U.S. patent application number 10/167316 was filed with the patent office on 2003-04-10 for methods of using electro-sensitive movable fluids.
This patent application is currently assigned to New Technology Management Inc.. Invention is credited to Edamura, Kazuya, Otsubo, Yasufumi, Yokota, Shinichi.
Application Number | 20030067225 10/167316 |
Document ID | / |
Family ID | 27456670 |
Filed Date | 2003-04-10 |
United States Patent
Application |
20030067225 |
Kind Code |
A1 |
Yokota, Shinichi ; et
al. |
April 10, 2003 |
Methods of using electro-sensitive movable fluids
Abstract
Provided is a method for creating fluid motion of an
electro-sensitive movable fluid upon application of
direct-current-voltage between two electrodes adjacent the fluid,
the fluid having a conductivity .sigma., and a viscosity .eta.
located inside a triangle in a graph showing a relation between a
conductivity .sigma. plotted as abscissa, and a viscosity .eta.,
plotted as ordinate, of a fluid at the working temperature, said
triangle having, as vertices, a point P indicated by the
conductivity .sigma.=4.times.10.sup.-10 S/m and the viscosity
.eta.=1.times.10.sup.0 Pa.multidot.s, a point Q indicated by the
conductivity .sigma.=4.times.10.sup.-10 S/m and the viscosity
.eta.1.times.10.sup.-4 Pa.multidot.s, and a point R indicated by
the conductivity .sigma.=5.times.10.sup.-6 S/m and the viscosity
.eta.1.times.10.sup.-4 Pa.multidot.s.
Inventors: |
Yokota, Shinichi;
(Sagamihara-City, JP) ; Otsubo, Yasufumi;
(Chiba-City, JP) ; Edamura, Kazuya; (Tokyo,
JP) |
Correspondence
Address: |
Kent E. Baldauf
Webb Ziesenheim Logsdon Orkin & Hanson
700 Koppers Building
436 Seventh Avenue
Pittsburgh
PA
15219
US
|
Assignee: |
New Technology Management
Inc.
|
Family ID: |
27456670 |
Appl. No.: |
10/167316 |
Filed: |
June 10, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10167316 |
Jun 10, 2002 |
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09358265 |
Jul 21, 1999 |
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09358265 |
Jul 21, 1999 |
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08792544 |
Jan 31, 1997 |
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6030544 |
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Current U.S.
Class: |
310/11 |
Current CPC
Class: |
H02N 11/006 20130101;
C10M 171/001 20130101; F03G 7/00 20130101; F15B 21/06 20130101 |
Class at
Publication: |
310/11 |
International
Class: |
G21D 007/02; H02K
044/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 1, 1996 |
JP |
16871/1996 |
Feb 1, 1996 |
JP |
16872/1996 |
Mar 29, 1996 |
JP |
76259/1996 |
Sep 12, 1996 |
JP |
241679/1996 |
Sep 12, 1996 |
JP |
248416/1996 |
Sep 19, 1996 |
JP |
248417/1996 |
Claims
What is claimed is:
1. An electro-sensitive movable fluid comprising a compound having
a conductivity .sigma. and a viscosity .eta. located inside a
rectangular triangle in a graph showing a relation between a
conductivity .sigma., plotted as abscissa, and a viscosity .eta.,
plotted as ordinate, of a fluid at the working temperature, said
rectangular triangle having, as vertexes, a point P indicated by
the conductivity .sigma.=4.times.10.sup.- -10 S/m and the viscosity
.eta.=1.times.10.sup.0 Pa.multidot.s, a point Q indicated by the
conductivity .sigma.=4.times.10.sup.-10 S/m and the viscosity
.eta.=1.times.10.sup.-4 Pa.multidot.s, and a point R indicated by
the conductivity .sigma.=5.times.10.sup.-6 S/m and the viscosity
.eta.=1.times.10.sup.-4 Pa.multidot.s, or comprising a mixture of
two or more kinds of compounds, said mixture being adjusted to have
a conductivity .sigma. and a viscosity .eta. located inside said
rectangular triangle.
2. The electro-sensitive movable fluid as claimed in claim 1,
wherein the point P is indicated by the conductivity
.sigma.=5.times.10.sup.-10 S/m and the viscosity
.eta.=8.times.10.sup.-1 Pa.multidot.s, the point Q is indicated by
the conductivity .sigma.=5.times.10.sup.-10 S/m and the viscosity
.eta.=2.times.10.sup.-4 Pa.multidot.s, and the point R is indicated
by the conductivity .sigma.=2.5.times.10.sup.-6 S/m and the
viscosity .eta.=2.times.10.sup.-4 Pa.multidot.s.
3. The electro-sensitive movable fluid as claimed in claim 1 or
claim 2, wherein the compound is a chain or branched, substantially
dielectric fluid compound containing molecular end group composed
of alkyl groups, outer ends of said groups inactivated by hydrogen
atoms bonding to the carbon atoms, said molecular end groups being
united by bonding to each other at the inner ends, in which the
bonding hand of each carbon atom for constituting the end groups
with the sealed ends is bonded to at least one hetero atom and
further linked to a straight-chain divalent hydrocarbon group,
which may have a hetero atom and may have a branch, through the
hetero atom, or is bonded to a divalent hydrocarbon group which may
have a hetero atom or may have a branch.
4. The electro-sensitive movable fluid as claimed in claim 3,
wherein the compound is at least one compound selected from
compounds represented by the following formulas [II], [II], [III],
[IV] and [V]: 64wherein X.sup.1 is a divalent group of 1 to 14
carbon atoms which may have either a branched chain, an ether
linkage or an ester linkage, and Y.sup.1 and Z.sup.1 are each
independently an alkyl group or 1 to 5 carbon atoms which may have
a branch; 65wherein X.sup.2 is a divalent alkyl group of 2 to 9
carbon atoms which may have a branch, Y.sup.2 is a divalent alkyl
group of 1 to 6 carbon atoms, Z.sup.2 is an alkyl group of 1 to 6
carbon atoms which may have a branch, n is an integer of 1 to 4, m
is an integer of 1 or 2, and in case of m=1, A is a hydrogen atom;
in case of m=2, said compound of this formula being a symmetric
dimer having A as a bonding hand in which groups each represented
by (Z.sup.2--O--(X.sup.2--O).sub.n-- -CO--Y.sup.2)--are directly
bonded to each other; 66wherein X.sup.3 is a monovalent group
having a carbon atoms, b oxygen atoms and 2a+1-2b hydrogen atoms (a
is an integer of 1 to 25, b is 0, 1, 2 or 3, and 2a+1 >2b), and
Y.sup.3 is a hydrocarbon group of 1 to 14 carbon atoms which may
have a branched chain and/or a carbon-to-carbon double bond;
67wherein R.sup.1 and R.sup.2 are each independently a hydrocarbon
group which may contain an atom other than carbon and hydrogen, and
may be the same as or different from each other, and X is a
divalent group represented by the following formula [VI] or [VII]:
68wherein R.sup.3 and R.sup.4 are each a hydrocarbon group which
may have a branch and to which an atom other than carbon and
hydrogen may be bonded, R.sup.3 and R.sup.4 may be the same as or
different from each other, q and r are each independently 0 or an
integer of 1 or more, when q or r is 0, R.sup.3 and R.sup.4 are
each independently a single bond, p is 0 or an integer of 1, 2 or
3, a cyclic structure regulated by p may have a substituent, and
the cyclic structure may be partly or wholly hydrogenated;
--C.sub.nH.sub.(2n-2m)-- [VII]wherein n is an integer of 2 or more,
and m is the number of double bonds contained in this group.
5. A method of driving the electro-sensitive movable fluid as
claimed in any one of claims 1 to 4, wherein said movable fluid
contains a small amount of a hydrocarbon compound having 5 to 10
carbon atoms.
6. A method of moving an electro-sensitive movable fluid,
comprising applying a voltage between at least two electrodes
arranged in an electro-sensitive movable fluid to move the
electro-sensitive movable fluid in the direction of one electrode
to the other electrode.
7. A method of converting electric energy to mechanical energy,
comprising the steps of arranging at least one pair of electrodes
in an electro-sensitive movable fluid, applying a voltage between
the electrodes to form jet flow of the electro-sensitive movable
fluid at a velocity corresponding to the applied electric energy,
and converting fluid energy of the jet flow of the
electro-sensitive movable fluid to mechanical energy capable of
being taken out.
8. A method of controlling energy conversion, comprising the steps
of arranging at least one pair of electrodes in a container filled
with an electro-sensitive movable fluid, applying a
direct-current-voltage between the electrodes to convert electric
energy to fluid energy of the electro-sensitive movable fluid by
changing the applied direct-current-voltage in a range of 0.1 V to
10 kV to control the flow velocity and the flow direction of the
electro-sensitive movable fluid in proportion to the applied
direct-current-voltage, and converting the fluid energy of the
movable fluid to mechanical energy capable of being taken out.
9. The method as claimed in claim 5 or 6, wherein at least one pair
of electrodes and a rotor are arranged in a container filled with
the electro-sensitive movable fluid and a direct-current-voltage
applied between the electrodes is changed in a range of 0.1 V to 10
kV to control a rotational speed and a rotational direction of the
rotor in proportion to the applied direct-current-voltage.
10. The method as claimed in any one of claims 6 to 9, wherein the
electro-sensitive movable fluid comprises a compound having a
conductivity .sigma. and a viscosity .eta. located inside a
rectangular triangle in a graph showing a relation between a
conductivity .sigma. plotted as abscissa, and a viscosity .eta.,
plotted as ordinate, of a fluid at the working temperature, said
rectangular triangle having, as vertexes, a point P indicated by
the conductivity .sigma.=4.times.10.sup.- -10 S/m and the viscosity
.eta.=1.times.10.sup.0 Pa.multidot.s, a point Q indicated by the
conductivity .sigma.=4.times.10.sup.-10 S/m and the viscosity
.eta.=1.times.10.sup.-4 Pa.multidot.s, and a point R indicated by
the conductivity .sigma.=5.times.10.sup.-6 S/m and the viscosity
.eta.=1.times.10.sup.-4 Pa.multidot.s, or comprises a mixture of
two or more kinds of compounds, said mixture being adjusted to have
a conductivity .sigma. and a viscosity .eta. located inside said
rectangular triangle.
11. The method as claimed in any one of claims 7 to 10, wherein the
electro-sensitive movable fluid is dibutyl decanedioate.
12. A motor for electro-sensitive movable fluid, including a
container to be filled with an electro-sensitive movable fluid, a
lid to close the container by being engaged with the open top of
the container, a cylindrical rotor rotatable inside the container
around a rotating shaft borne by a shaft hole provided at the
center of the lid and a bearing section provided at the center of
the bottom of the container, plural first electrodes which are
electrically connected with external electrode terminals through
the rotating shaft at the upper part of the cylindrical rotor and
arranged in the vertical direction on the surface of the
cylindrical rotor, and second electrodes which are electrically
connected with external electrode terminals through the rotating
shaft at the lower part of the cylindrical rotor and arranged in
non-contact with the first electrodes and in the vertical direction
on the surface of the cylindrical rotor.
13. The motor for electro-sensitive movable fluid as claimed in
claim 12, wherein the plural first and second electrodes arranged
in the vertical direction on the surface of the cylindrical rotor
are each made of a conductive material and the interval angle
between the electrodes is in the range of 1.degree. to
180.degree..
14. A method of driving a motor for electro-sensitive movable
fluid, said motor including a container to be filled with an
electro-sensitive movable fluid, a lid to close the container by
being engaged with the open top of the container, a cylindrical
rotor rotatable inside the container around a rotating shaft borne
by a shaft hole provided at the center of the lid and a bearing
provided at the center of the bottom of the container, plural first
electrodes which are electrically connected with first external
electrode terminals through the rotating shaft at the upper part of
the cylindrical rotor and arranged in the vertical direction on the
surface of the cylindrical rotor, and second electrodes which are
electrically connected with second external electrode terminals
through the rotating shaft at the lower part of the cylindrical
rotor and arranged in non-contact with the first electrodes and in
the vertical direction on the surface of the cylindrical rotor;
which comprises applying a direct-current-voltage between the first
and second electrodes to produce jet flow of the electro-sensitive
movable fluid in the fluid container and thereby rotate the
cylindrical rotor together with the electrodes.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to electro-sensitive movable
fluids which flow by application of a direct-current-voltage,
methods of using the movable fluids and motors using the movable
fluids.
BACKGROUND OF THE INVENTION
[0002] It is known that the characteristics of certain kinds of
dielectric fluids vary when the dielectric fluids are subjected to
electric fields. In case of liquid crystals, for example, when a
voltage is applied to liquid crystal compounds in a liquid crystal
phase (i.e., intermediate phase between a solid phase and a liquid
phase), orientation properties of the compounds are controlled to
thereby adjust light transmittance of the compounds, whereby
visible images are formed. However, even if the liquid crystal
compounds regulated by the orientation plates are placed in
electric fields, they cannot flow freely because they are not
liberated from the regulation.
[0003] Also, some fluids are known to exert an effect of variation
of properties such as viscosity (electrical rheology effect or
Winslow Effect).
[0004] The fluids exerting electrical rheology effect or Wien
effect are generally colloidal dispersions wherein solid
components, such as silica gel, cellulose, casein and polystyrene
ion exchange resins, are mixed with insulating oils and dispersed
in the oils, so that the storage stability of such fluids is
low.
[0005] As lubricating oils for automobiles, those exhibiting
electrical rheology effect have been proposed, but such lubricating
oils are also heterogeneous and have a problem of low storage
stability.
[0006] In Japanese Patent Laid-Open Publications No. 57274/1994 and
No. 73390/1994, inventions of electrosensitive compositions wherein
insulating oils are blended with specific fluorine compounds are
disclosed.
[0007] The compositions disclosed in those publications are
mixtures of insulating oils and fluorine compounds, and therefore
they have a problem in the storage stability. Additionally, there
is a worldwide tendency to avoid the use of fluorine compounds in
recent years.
OBJECT OF THE INVENTION
[0008] An object of the present invention is to provide an
electro-sensitive movable fluid which flows upon application of a
direct-current-voltage, a method of using the movable fluid and a
motor using the movable fluid.
[0009] More particularly, the object of the invention is to provide
an electro-sensitive movable fluid, wherein jet flow is induced by
the electric energy of a direct-current-voltage applied to the
movable fluid, said jet flow of the movable fluid being able to be
taken out as mechanical energy such as rotational energy.
[0010] It is another object of the invention to provide an energy
conversion method using the electro-sensitive movable fluid wherein
the electric energy of a direct-current-voltage applied to the
movable fluid is converted to energy in the other form.
[0011] It is a further object of the invention to provide a novel
motor using the electro-sensitive movable fluid.
SUMMARY OF THE INVENTION
[0012] The electro-sensitive movable fluid of the invention
comprises a compound having a conductivity .sigma. and a viscosity
.eta. located inside a rectangular triangle in a graph showing a
relation between a conductivity .sigma., plotted as abscissa, and a
viscosity .eta., plotted as ordinate, of a fluid at the working
temperature, said rectangular triangle having, as vertexes, a point
P indicated by the conductivity .sigma.=4.times.10.sup.-10 S/m and
the viscosity .eta.=1.times.10.sup.0 Pa.multidot.s, a point Q
indicated by the conductivity .sigma.=4.times.10.sup.-10 S/m and
the viscosity .eta.=1.times.10.sup.-4 Pa.multidot.s, and a point R
indicated by the conductivity .sigma.=5.times.10.sup.-6 S/m and the
viscosity .eta.=1.times.10.sup.-4 Pa.multidot.s, or comprises a
mixture of two or more kinds of compounds, said mixture being
adjusted to have a conductivity .sigma. and a viscosity .eta.
located inside said rectangular triangle.
[0013] The electro-sensitive movable fluid may be an inorganic
compound or an organic compound. When the electro-sensitive movable
fluid is an organic compound, this organic compound preferably is a
chain or branched, substantially dielectric fluid compound
containing molecular end group composed of alkyl groups, outer ends
of said groups inactivated by hydrogen atoms bonding to the carbon
atoms, said molecular end groups being united by bonding to each
other at the inner ends, in which the bonding hand of each carbon
atom for constituting the end groups with the sealed ends is bonded
to at least one hetero atom and further linked to a straight-chain
divalent hydrocarbon group, which may have a hetero atom and may
have a branch, through the hetero atom, or is bonded to a divalent
hydrocarbon group which may have a hetero atom or may have a
branch.
[0014] When a voltage is applied between at least two electrodes
arranged in the electro-sensitive movable fluid of the invention,
the electro-sensitive movable fluid can be moved in the direction
of one electrode to the other electrode.
[0015] Further, using the electro-sensitive movable fluid, the
electric energy can be converted to energy of other form by a
method comprising the steps of arranging at least one pair of
electrodes in the electro-sensitive movable fluid, applying a
voltage between the electrodes to form jet flow of the
electro-sensitive movable fluid at a velocity corresponding to the
applied electric energy, and converting fluid energy of the jet
flow of the electro-sensitive movable fluid to mechanical energy
capable of being taken out. In this case, the energy conversion
using the electro-sensitive movable fluid can be controlled by a
method comprising the steps of arranging at least one pair of
electrodes in a container filled with the electro-sensitive movable
fluid, applying a direct-current-voltage between the electrodes to
convert electric energy to fluid energy of the electro-sensitive
movable fluid by changing the applied direct-current-voltage in a
range of 0.1 V to 10 kV to control the flow velocity and the flow
direction of the electro-sensitive movable fluid in proportion to
the applied direct-current-voltage, and converting the fluid energy
of the movable fluid to mechanical energy capable of being taken
out.
[0016] The first motor for electro-sensitive movable fluid
(referred to as "RE type ECF motor" hereinafter, ECF:
electro-conjugated fluid), which is preferably employed for the
energy conversion, includes a container to be filled with an
electro-sensitive movable fluid, a lid to close the container by
being engaged with the open top of the container, a cylindrical
rotor rotatable inside the fluid container around a rotating shaft
borne by a shaft hole provided at the center of the lid and a
bearing section provided at the center of the bottom of the
container, plural first electrodes which are electrically connected
with external electrode terminals through the rotating shaft at the
upper part of the cylindrical rotor and arranged in the vertical
direction on the surface of the cylindrical rotor, and second
electrodes which are electrically connected with external electrode
terminals through the rotating shaft at the lower part of the
cylindrical rotor and arranged in non-contact with the first
electrodes and in the vertical direction on the surface of the
cylindrical rotor. The electro-sensitive movable fluid of the
invention can drive the second motor for electro-sensitive movable
fluid (referred to as "SE type ECF motor" hereinafter) other than
the RE type ECF motor. The SE type ECF motor includes a cylindrical
container to be filled with the electro-sensitive movable fluid, a
lid of the container and a vane rotor, vanes of which detect motion
of the movable fluid induced by application of a voltage to thereby
rotate the rotor. The cylindrical container is provided with slits
where the electrodes are arranged, and from the slits at least one
pair of electrodes extend along the inner wall surface of the
container.
[0017] As described above, the RE type ECF motor includes a
container to be filled with an electro-sensitive movable fluid, a
lid to close the container by being engaged with the open top of
the container, a cylindrical rotor rotatable inside the container
around a rotating shaft borne by a shaft hole provided at the
center of the lid and a bearing section provided at the center of
the bottom of the container, plural first electrodes which are
electrically connected with first external electrode terminals
through the rotating shaft at the upper part of the cylindrical
rotor and arranged in the vertical direction on the surface of the
cylindrical rotor, and second electrodes which are electrically
connected with second external electrode terminals through the
rotating shaft at the lower part of the cylindrical rotor and
arranged in non-contact with the first electrodes and in the
vertical direction on the surface of the cylindrical rotor. In the
case of this motor, when a direct-current-voltage is applied
between the first and second electrodes, jet flow of the
electro-sensitive movable fluid is produced in the fluid container,
whereby the rotor can be rotated together with the electrodes.
[0018] When a certain kind of a dielectric fluid (i.e.,
"electro-sensitive movable fluid" of the. invention) is subjected
to an electric field, an electric force is generated in the fluid
owing to the nonuniformity of electric conductivity and dielectric
constant inside the fluid. In the direct current field, the Coulomb
force acting on space charge dominates the dielectrophoretic force.
This Coulomb force causes hydrodynamic instability, resulting in
occurrence of convection of the electro-sensitive movable fluid or
a secondary motion of the fluid. These phenomena are called as
"electrohydrodynamic (EHD) effects".
[0019] The present inventors have found that the electric energy
can be readily converted to mechanical energy utilizing the EHD
effects and succeeded in specifying a dielectric fluid capable of
exerting the EHD effects. That is, the electro-sensitive movable
fluid of the invention inherently is a dielectric fluid, but when
the movable fluid is subjected to an electric field, electric
current is brought about, though it is very small. When a
direct-current-voltage is applied to the electro-sensitive movable
fluid as described above, the movable fluid is moved owing to the
EHD effects, whereby jet flow of the movable fluid is generated.
The intensity (or rate) of the jet flow varies with the applied
direct-current-voltage. Therefore, when the motion (jet flow) of
the electro-sensitive movable fluid is captured and taken out, the
electric energy can be utilized as mechanical energy transformed
from the electric energy.
[0020] The present inventors consider that the motion of the
electro-sensitive movable fluid in the invention is owing to the
EHD effects. This means that the present inventors consider that
the phenomenon occurring in the invention can be related with the
"EHD effects", but they do not conclude that the phenomenon
occurring in the invention is owing to the "EHD effects".
BRIEF DESCRIPTION OF THE DRAWING
[0021] FIG. 1 graphically shows a relation between viscosity and
conductivity of the dielectric fluid (electro-sensitive movable
fluid).
[0022] FIG. 2 schematically shows an embodiment of the SE type ECF
motor using the electro-sensitive movable fluid and an embodiment
of arrangement of the electrodes.
[0023] FIG. 3 schematically shows an embodiment of the RE type ECF
motor using the electro-sensitive movable fluid and an embodiment
of arrangement of the electrodes.
[0024] 1: SE type ECF motor
[0025] 2: container (outer cylinder)
[0026] 4: lid
[0027] 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h: electrode
[0028] 6: vane
[0029] 18: vane rotor
[0030] 22: electro-sensitive movable fluid
[0031] 40: RE type ECF motor
[0032] 41: container (outer cylinder)
[0033] 42: second electrode
[0034] 43: first electrode
[0035] 44: lid
[0036] 45: rotating shaft
[0037] 46: cylindrical rotor
[0038] 47: shaft hole
[0039] 48: bearing section
[0040] 49: bottom
[0041] 50, 60: rotational contact point
[0042] 52, 53: external terminal
[0043] FIG. 4 schematically shows a device to measure output torque
of the SE type ECF motor and the RE type ECF motor in Example
5.
[0044] FIG. 5 shows an example of behaviors of the
electro-sensitive movable fluid when a direct-current-voltage is
applied to the movable fluid contained in the container.
[0045] FIG. 6 schematically shows a fluidic components using the
electro-sensitive movable fluid.
[0046] FIG. 7 graphically shows a relation between rotational speed
and applied voltage and a relation between electric current and
applied voltage in the SE type ECF motor.
[0047] FIG. 8 to FIG. 10 graphically show variability of rotational
speed, output torque or motor output power density when dibutyl
decanedioate is used as the electro-sensitive movable fluid and the
applied voltage, the number of vanes, the diameter of the rotor,
the diameter of the fluid container or the number of electrodes is
varied.
[0048] FIG. 11 schematically shows a device which is used in
Example 7, etc. to measure output torque.
DETAILED DESCRIPTION OF THE INVENTION
[0049] The electro-sensitive movable fluid of the present
invention, the method of using the movable fluid, particularly the
method of converting electric energy to mechanical energy using the
movable fluid, and the motor capable of being driven by the use of
the movable fluid are described in detail hereinafter.
[0050] The electro-sensitive movable fluid of the invention can be
specified by the conductivity and the viscosity.
[0051] When the conductivity .sigma. and the viscosity .eta. of
fluids (generally called "dielectric fluids") are measured under
the conditions of an electric field intensity of 2 kVmm.sup.-1 and
a temperature of 25.degree. C., the dielectric fluids are
distributed as shown in FIG. 1.
[0052] Further, when the SE type ECF motor and the RE type ECF
motor are driven using the dielectric fluids, these fluids are
classified into a group capable of driving those motors and a group
incapable of driving those motors. In FIG. 1, the fluids capable of
driving the SE type ECF motor and the RE type ECF motor are
represented by the symbol .diamond-solid., and those incapable of
driving the motors are represented by the symbol .diamond..
[0053] The dielectric fluid serving as the electro-sensitive
movable fluid of the invention comprises a compound having, at its
working temperature, a conductivity .sigma. and a viscosity .eta.
located inside a rectangular triangle in a graph (FIG. 1) wherein
the conductivity .sigma. is plotted as abscissa and the viscosity
.eta. is plotted as ordinate, said rectangular triangle having the
following points P, Q and R as vertexes, or the fluid comprises a
mixture of two or more kinds of compounds, said mixture being
adjusted to have a conductivity .sigma. and a viscosity .eta.
located inside the above rectangular triangle.
1 TABLE 1 Conductivity (.sigma.) Viscosity (.eta.) Point P 4
.times. 10.sup.-10 S/m 1 .times. 10.sup.0 Pa .multidot. S (Point
P.sup.0) preferably preferably 5 .times. 10.sup.-10 S/m 8 .times.
10.sup.-1 Pa .multidot. S Point Q 4 .times. 10.sup.-10 S/m 1
.times. 10.sup.-4 Pa .multidot. S (Point Q.sup.0) preferably
preferably 5 .times. 10.sup.-10 S/m 2 .times. 10.sup.-4 Pa
.multidot. S Point R 5 .times. 10.sup.-6 S/m 1 .times. 10.sup.-4 Pa
.multidot. S (Point R.sup.0) preferably preferably 2.5 .times.
10.sup.-6 S/m 2 .times. 10.sup.-4 Pa .multidot. S
[0054] In Table 1, the points P.sup.0, Q.sup.0 and R.sup.0 are
particularly preferable points as the vertexes of the triangle
wherein the electro-sensitive movable fluid of the invention is
located.
[0055] The electro-sensitive movable fluid of the invention is a
substantially dielectric fluid. The conductivity .sigma. of
ordinary dielectric fluids, as measured at an electric field
intensity of 2 kVmm.sup.-1 and a temperature of 25.degree. C., is
usually in the range of 1.times.10.sup.-1 S/M to 1.times.10.sup.-17
S/m. However, the electro-sensitive movable fluid of the invention
is a dielectric fluid having a conductivity .sigma. of
4.times.10.sup.-10 to 5.times.10.sup.-6 S/m, preferably
5.times.10.sup.-10 to 2.5.times.10.sup.-6 S/m. Further, the
dielectric fluid employable as the electricity-sensitive working
liquid of the invention has a viscosity .eta. of 1.times.10.sup.-4
Pa.multidot.s to 1.times.10.sup.0 Pa.multidot.s, preferably
2.times.10.sup.-4 Pa.multidot.s to 8.times.10.sup.-1
Pa.multidot.s.
[0056] The reason why the electro-sensitive movable fluid of the
invention has the above conductivity and viscosity is not clear,
but it is assumably as follows.
[0057] In the below-described SE type ECF motor and RE type ECF
motor, the important factor of controlling the rotary motion is a
conductivity of the fluid. Occurrence of the EHD
(electrohydrodynamic) motion of the fluid in a direct current field
requires presence of free charge. Generation of the free charge
results from dissociation of neutral molecule and injection of
charge from electrodes. It is thought that free charge is generated
when the dielectric fluid having a conductivity within the above
range is used as the electro-sensitive movable fluid of the
invention and that upon application of a direct-current-voltage,
jet flow of the electro-sensitive movable fluid is produced owing
to the free charge. It is also thought that the viscosity of the
electro-sensitive movable fluid has influence on the efficiency in
transference of the kinetic energy of the fluid jet flow to the
rotor.
[0058] The materials having such conductivity and viscosity include
organic ones and inorganic ones. The electro-sensitive movable
fluid of the invention may be either of organic and inorganic
materials.
[0059] Some examples of the organic compounds which have the above
properties and are employable as the electro-sensitive movable
fluid of the invention are given below.
[0060] (1) Dibutyl adipate (DBA)
(.sigma.=3.01.times.10.sup.-9 S/m, .eta.=3.5.times.10.sup.-3
Pa.multidot.s)
[0061] (6) Triacetin
(.sigma.=3.64.times.10.sup.-9 S/m, .eta.=1.4.times.10.sup.-2
Pa.multidot.s)
[0062] 1
[0063] (11) Butyl cellosolve acetate
(.sigma.=2.10.times.10.sup.-8 S/m, .eta.=7.0.times.10.sup.-4
Pa.multidot.s)
[0064] (12) Butyl carbitol acetate
(.sigma.=5.20.times.10.sup.-8 S/m, .eta.=1.7.times.10.sup.-3
Pa.multidot.s)
[0065] (13) 3-Methoxy-3-methylbutyl acetate (Solfit AC)
(.sigma.=8.30.times.10.sup.-8 S/m, .eta.=6.0.times.10.sup.-4
Pa.multidot.s)
[0066] (14) Dibutyl fumarate (DBF)
(.sigma.=2.65.times.10.sup.-9 S/m, .eta.=3.5.times.10.sup.-3
Pa.multidot.s)
[0067] (17) Propylene glycol methyl ether acetate (PMA)
(.sigma.=1.56.times.10.sup.-7 S/m, .eta.=6.0.times.10.sup.-4
Pa.multidot.s)
[0068] 2
[0069] (18) Methyl acetyl ricinoleate (MAR-N)
(.sigma.=1.30.times.10.sup.-8 S/m, .eta.=1.3.times.10.sup.-2
Pa.multidot.s)
[0070] 3
[0071] (20) Dibutyl itaconate (DBI)
(.sigma.=1.46.times.10.sup.-8 S/m, .eta.=3.5.times.10.sup.-3
Pa.multidot.s)
[0072] 4
[0073] (23) 2,2,4-Trimethyl-1,3-pentanediol diisobutyrate (trade
name: Kyowanol D)
(.sigma.=6.24.times.10.sup.-9 S/m, .eta.=4.0.times.10.sup.-3
Pa.multidot.s)
[0074] 5
[0075] (26) Propylene glycol ethyl ether acetate (trade name:
BP-Ethoxypropyl Acetate)
(.sigma.=3.10.times.10.sup.-8 S/m, .eta.=6.0.times.10.sup.-4
Pa.multidot.s)
[0076] 6
[0077] (27) 9,10-Epoxy butyl stearate (trade name: Sansocizer
E-4030)
(.sigma.=5.46.times.10.sup.-9 S/m, .eta.=2.0.times.10.sup.-2
Pa.multidot.s)
[0078] 7
[0079] (28) Tetrahydrophthalic acid dioctyl ether (trade name:
Sansocizer DOTP)
(.sigma.=6.20.times.10.sup.-10 S/m, .eta.=4.0.times.10.sup.-2
Pa.multidot.s)
[0080] (33) 1-Ethoxy-2-acetoxypropane
(.sigma.=4.41.times.10.sup.-7 S/m, .eta.=4.0.times.10.sup.-4
Pa.multidot.s)
[0081] (35) Linalyl acetate
(.sigma.=1.82.times.10.sup.-9 S/m, .eta.=1.3.times.10.sup.-3
Pa.multidot.s)
[0082] 8
[0083] (36) Dibutyl decanedioate
(.sigma.=1.35.times.10.sup.-9 S/m, .eta.=7.0.times.10.sup.-3
Pa.multidot.s)
[0084] When a combination of plural compounds is used as the
electro-sensitive movable fluid of the invention, the conductivity
and the viscosity of a mixture of the plural compounds can be made
to be located inside the triangle defined by the points P, Q and R
shown in FIG. 1.
[0085] In other words, even if each of compounds has a conductivity
and/or a viscosity out of the above range, a mixture of the
compounds is employable as the electro-sensitive movable fluid of
the invention, as far as the conductivity and the viscosity of the
mixture are within the above range, respectively.
[0086] For example, a mixture (37) (.sigma.=2.60.times.10.sup.-9
S/m, .eta.=9.8.times.10.sup.-3 Pa.multidot.s) of
2,2,4-trimethyl-1,3-pentanedi- ol monoisobutyrate (trade name:
Kyowanol M, .sigma.=6.80.times.10.sup.-8 S/m,
.eta.=1.2.times.10.sup.-2 Pa-s) and 2-ethylhexyl palmitate (trade
name: Exepal EH-P, .sigma.=2.60.times.10.sup.-10 S/m,
.eta.=9.5.times.10.sup.-3 Pa.multidot.s) in a mixing ratio of 1:4
by weight, each having a conductivity and a viscosity out of the
above range, is employable as the electro-sensitive movable fluid.
Also, a mixture (38) (.sigma.=4.17.times.10.sup.-9 S/m,
.eta.=5.0.times.10.sup.-3 Pa.multidot.s) of DAM (diallyl maleate,
.sigma.=7.8.times.10.sup.-7 S/M, .eta.=2.5.times.10.sup.-3
Pa.multidot.s) and butyl stearate (trade name: Exepal BS,
.sigma.=3.1.times.10.sup.-10 S/m, .eta.=8.5.times.10.sup.-3
Pa.multidot.s) in a mixing ratio of 1:4 by weight, each having a
conductivity and a viscosity out of the above range, is employable
as the electro-sensitive movable fluid.
[0087] The requisite of the electro-sensitive movable fluid of the
invention is that the movable fluid has the above-defined
conductivity and viscosity. The conductivity and viscosity
mentioned above are measured at room temperature, but these
property values are known to vary depending on the measuring
temperature. The conductivity and the viscosity defined in the
invention are irrespective of the temperature. That is, even the
compounds having a conductivity and a viscosity out of the above
range at room temperature (25.degree. C.) are employable as the
electro-sensitive movable fluids, as far as the conductivity and
the viscosity of the compounds are within the above range at their
working temperatures, e.g., high temperatures or low temperatures.
For example, the compound (15), 2-ethylhexyl benzyl phthalate
(trade name: Placizer B-8), has a conductivity .sigma. of
1.10.times.10.sup.-8 S/m and a viscosity .eta. of
7.8.times.10.sup.-2 Pa.multidot.s at room temperature, and even if
a direct-current-voltage of 6 kV is applied to the compound at
25.degree. C., the SE type ECF motor or the RE type ECF motor with
the compound (25) cannot be driven. To the contrary, a heated
product (39) obtained by heating 2-ethylhexyl benzyl phthalate at
100.degree. C., has a conductivity .sigma. of 9.90.times.10.sup.-9
S/m and a viscosity of 3.5.times.10.sup.-2 Pa.multidot.s (at
100.degree. C.), and therefore the SE type ECF motor or the RE type
ECF motor with the heated product (39) can be driven by applying a
direct-current-voltage of 6 kV to the product (39).
[0088] On the other hand, at room temperature (25.degree. C), none
of the below-described compounds have a conductivity .sigma. and a
viscosity .eta. located inside the triangle formed by the points P,
Q and R in FIG. 1. Therefore, those compounds cannot drive the SE
type ECF motor or the RE type ECF motor at 25.degree. C. when they
are used singly.
[0089] (2) Tributyl citrate (TBC)
(.sigma.=5.71.times.10.sup.-7 S/m, .eta.=2.0.times.10.sup.-2
Pa.multidot.s)
[0090] (3) Monobutyl maleate (MBM)
(.sigma.=2.60.times.10.sup.-5 S/m, .eta.=2.0.times.10.sup.-2
Pa.multidot.s)
[0091] (4) Diallyl maleate (DAM)
(.sigma.=7.80.times.10.sup.-7 S/m, .eta.=2.5.times.10.sup.-3
Pa.multidot.s)
[0092] (5) Dimethyl phthalate (DMP)
(.sigma.=3.90.times.10.sup.-7 S/m, .eta.=1.2.times.10.sup.-2
Pa.multidot.s)
[0093] (7) Ethyl cellosolve acetate
(.sigma.=7.30.times.10.sup.-5 S/m, .eta.=9.0.times.10.sup.-4
Pa.multidot.s)
[0094] (8) 2-(2-Ethoxyethoxy)ethyl acetate
(.sigma.=6.24.times.10.sup.-7 S/m, .eta.=1.4.times.10.sup.-2
Pa.multidot.s)
[0095] (9) 1,2-Diacetoxyethane
(.sigma.=2.00.times.10.sup.-6 S/m, .eta.=1.5.times.10.sup.-3
Pa.multidot.s)
[0096] (10) Triethylene glycol diacetate
(.sigma.=5.20.times.10.sup.-7 S/m, .eta.=8.1.times.10.sup.-3
Pa.multidot.s)
[0097] (15) 2-Ethylhexyl Benzyl phthalate (trade name: Placizer
B-8)
(.sigma.=1.10.times.10.sup.-8 S/m, .eta.=7.8.times.10.sup.-2
Pa.multidot.s)
[0098] (19) 2-Ethylhexyl palmitate (trade name: Exepal EH-P)
(.sigma.=2.60.times.10.sup.-10 S/m, .eta.=9.5.times.10.sup.-3
Pa.multidot.s)
[0099] (21) Polyethylene glycol monooleate (trade name: Emanone
4110)
(.sigma.=3.75.times.10.sup.-7 S/m, .eta.=8.0.times.10.sup.-2
Pa.multidot.s)
[0100] (22) Butyl stearate (trade name: Exepal BS)
(.sigma.=3.10.times.10.sup.-10 S/m, .eta.=8.5.times.10.sup.-3
Pa.multidot.s)
[0101] (24) 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate (trade
name: Kyowanol M)
(.sigma.=6.80.times.10.sup.-8 S/m, .eta.=1.2.times.10.sup.-2
Pa.multidot.s)
[0102] (25) Propylene glycol monoethyl ether
(.sigma.=6.24.times.10.sup.-5 S/m, .eta.=8.0.times.10.sup.-4
Pa.multidot.s)
[0103] (29) Tributyl phosphate (TBP)
(.sigma.=2.20.times.10.sup.-6 S/m, .eta.=2.2.times.10.sup.-3
Pa.multidot.s)
[0104] (30) Tributoxyethyl phosphate (TBXP)
(.sigma.=1.10.times.10.sup.-5 S/m, .eta.=9.0.times.10.sup.-3
Pa.multidot.s)
[0105] (31) Tris(chloroethyl) phosphate (CLP)
(.sigma.=7.80.times.10.sup.-6 S/m, .eta.=3.0.times.10.sup.-2
Pa.multidot.s)
[0106] (32) Ethyl 2-methylacetoacetate
(.sigma.=1.00.times.10.sup.-4 S/m, .eta.=5.0.times.10.sup.-4
Pa.multidot.s)
[0107] (34) 2-(2,2-Dichlorovinyl)-3,3-dimethylcyclopropane
carboxylic acid methyl ester (DCM-40)
(.sigma.=2.60.times.10.sup.-5 S/m, .eta.=5.5.times.10.sup.-3
Pa.multidot.s)
[0108] 9
[0109] The electro-sensitive movable fluid of the invention, which
is identified by the conductivity a and the viscosity .eta. as
described above and is an organic material, preferably has the
following structure.
[0110] That is, the electro-sensitive movable fluid of the
invention preferably comprises a chain or branched, substantially
dielectric fluid compound containing molecular end group composed
of alkyl groups, outer ends of said groups inactivated by hydrogen
atoms bonding to the carbon atoms, said molecular end groups being
united by bonding to each other at the inner ends, in which the
bonding hand of each carbon atom for constituting the end groups
with the sealed ends is bonded to at least one hetero atom and
further linked to a straight-chain divalent hydrocarbon group,
which may have a hetero atom and may have a branch, through the
hetero atom, or is bonded to a divalent hydrocarbon group which may
have a hetero atom or may have a branch.
[0111] The electro-sensitive movable fluid having the above
structure is preferably at least one compound selected from the
compounds represented by the following formulas [I], [II], [III],
[IV] and [V].
[0112] The compound represented by the following formula [I] is
employable as the electro-sensitive movable fluid of the invention.
10
[0113] In the formula [I], X.sup.1 is a divalent group of 1 to 14
carbon atoms. This divalent group may be a straight-chain group or
a branched group. Further, X.sup.1 may be a hydrocarbon group
composed of a carbon atom and a hydrogen atom, and it may further
have hetero atoms (atoms other than carbon atom and hydrogen atom),
such as an oxygen atom, a nitrogen atom and a sulfur atom. Of such
divalent groups, those having an oxygen atom are, for example,
groups having an ether linkage or groups having an ester
linkage.
[0114] Examples of the straight-chain groups among the divalent
groups of 1 to 14 carbon atoms include --CH.sub.2--,
--CH.sub.2CH.sub.2--, --CH.sub.2CH.sub.2CH.sub.2--,
--CH.sub.2CH.sub.2CH.sub.2CH.sub.2--and --(CH.sub.2).sub.n-- (n is
an integer of 5 to 14).
[0115] The branched hydrocarbon group is a divalent group having
usually 3 to 14 carbon atoms, preferably 4 to 14 carbon atoms, and
some examples thereof are given below. 11
[0116] In the formula [I], when X.sup.1 is a divalent group having
an oxygen atom, examples of the divalent groups having an ether
linkage include the following groups. 12
[0117] In the formula [I], when X.sup.1 is a divalent group having
an oxygen atom, examples of the divalent groups having an ester
linkage include the following groups. 13
[0118] In the formula [I], Y.sup.1 and Z.sup.1 are each
independently an alkyl group of 1 to 5 carbon atoms, and examples
thereof include methyl, ethyl, n-propyl, iso-propyl, n-butyl,
iso-butyl, tert-butyl, n-pentyl and iso-pentyl. Each of Y.sup.1 and
Z.sup.1 may be a straight-chain alkyl group or a branched alkyl
group. Y.sup.1 and Z.sup.1 may be the same as or different from
each other.
[0119] Listed below are some examples of the compounds represented
by the formula [I] wherein X.sup.1, Y.sup.1 and Z.sup.1 are such
groups as mentioned above, which are suitably used as the
electro-sensitive movable fluid. 2,2,4-Trimethyl-1,3-pentanediol
diisobutyrate 14
[0120] The compound represented by the following formula [II] is
employable as the electro-sensitive movable fluid of the invention.
15
[0121] In the formula [II], X.sup.2 is a divalent hydrocarbon group
of 2 to 9 carbon atoms, preferably 2 to 5 carbon atoms, which may
have a branch. Y.sup.2 is a divalent alkyl group of 1 to 6 carbon
atoms which may have a branch. Some examples of such alkyl groups
are given below. 16
[0122] In the formula [II], Z.sup.2 is an alkyl group of 1 to 6
carbon atoms which may have a branch. Some examples of such alkyl
groups are given below. 17
[0123] In the formula [II], n is an integer of 1 to 4, preferably
an integer of 1 to 3, more preferably an integer of 1 or 2.
[0124] m is an integer of 1 or 2. When m is 1, A is a hydrogen
atom. When m is 2, the compound of the formula [II] is a symmetric
dimer having A as a bonding hand wherein groups which are each
represented by (Z.sup.2--O--(X.sup.2--O).sub.n--CO--Y.sup.2)-are
directly bonded to each other.
[0125] Listed below are examples of the compounds represented by
the formula [II]. 18 19
[0126] The compound represented by the following formula [III] is
employable as the electro-sensitive movable fluid of the invention.
20
[0127] In the formula [III], X.sup.3 is a monovalent group having
carbon atoms (a), oxygen atoms (b) and hydrogen atoms (2a+1-2b)
wherein a is an integer of 1 to 25, b is 0, 1, 2 or 3, and a and b
are numbers satisfying the condition of 2a+1>2b, preferably a
monovalent group which may have one oxygen atom as an epoxy group
or a carbonyl group and has 1 to 17 carbon atoms. Y.sup.3 is a
hydrocarbon group of 1 to 14 carbon atoms which may have a branched
chain and/or a carbon-to-carbon double bond, preferably a
hydrocarbon group of 2 to 10 carbon atoms.
[0128] Listed below are examples of the compounds represented by
the formula [III]. 21
[0129] The compound represented by the following formula [IV] or
[V] is employable as the electro-sensitive movable fluid of the
invention. 22
[0130] In the formulas [IV] and [V], R.sup.1 and R.sup.2 are each
independently a hydrocarbon group of usually 1 to 15 carbon atoms,
preferably 1 to 9 carbon atoms, but they may be each independently
a hydrocarbon group having an atom other than carbon and hydrogen.
R.sup.1 and R.sup.2 may be the same as or different from each
other.
[0131] In the formulas [IV] and [V], X is a divalent group
represented by the following formula [VI] or [VII]. 23
[0132] In the formula [VI], R.sup.3 and R.sup.4 are each basically
a divalent hydrocarbon group of usually 1 to 5 carbon atoms,
preferably 1 to 2 carbon atoms. This hydrocarbon group may have a
branch, and to the hydrocarbon group, an atom other than carbon and
hydrogen may be bonded. R.sup.3 and R.sup.4 may be the same as or
different from each other.
[0133] In the formula [VI], q and r are each independently 0 or an
integer of 1 or more, and when q or r is 0, R.sup.3 and R.sup.4 are
each independently a single bond.
[0134] In the formula [VI], p is 0 or an integer of 1, 2 or 3. The
cyclic structure regulated by p may have a substituent, and the
cyclic structure may be partly or wholly hydrogenated.
--C.sub.nH.sub.(2n-2m)-- [VII]
[0135] In the formula [VII], n is an integer of 2 or more, and m is
the number of double bonds contained in this group. That is, the
group represented by the formula [VII] has a double bond.
[0136] Listed below are examples of the compounds represented by
the formula [IV] or [V].
[0137] Dialkyl itaconates
[0138] e.g., Dibutyl itaconate, e.g., Diethyl itaconate 24
[0139]
[0140] Alkyl acetyl ricinoleates
[0141] e.g., Methyl acetyl ricinoleate 25
[0142] Dialkyl fumarates
[0143] e.g., Dibutyl fumarate 26
[0144] e.g., Bis(2-ethylhexyl) fumarate 27
[0145] Dialkyl adipates
[0146] e.g., dibutyl adipate 28
[0147] e.g., Bis(2-ethylhexyl) adipate 29
[0148] Dialkyl azelates
[0149] e.g., Bis(2-ethylhexyl) azelate 30
[0150] e.g., Dibutyl azelate 31
[0151] Phthalic acid derivatives
[0152] e.g., Butyl benzyl phthalate 32
[0153] Dialkyl phthalates
[0154] e.g., Bis(n-octyl) phthalate
C.sub.6H.sub.4(COO-n-C.sub.8H.sub.17).sub.2
[0155] Dialkyl decanedioates
[0156] e.g., Dibutyl decanedioate
C.sub.4H.sub.9--O--OC--(CH.sub.2).sub.8--CO--O--C.sub.4H.sub.9
[0157] e.g., Bis(2-ethylhexyl) decanedioate 33
[0158] Dialkyl naphthenates
[0159] e.g., Dibutyl naphthenate 34
[0160] Of the compounds represented by the formulas [I] to [V], the
compound employable as the electro-sensitive movable fluid of the
invention needs to have a conductivity .sigma. and a viscosity
.eta., at its working temperature, located inside the triangle
formed by the points P, Q and R in the graph shown in FIG. 1. When
the electro-sensitive movable fluid is an organic compound, the
compound preferably has a structure represented by the formula [I],
[II] or [III].
[0161] The compounds serving as the electro-sensitive movable
fluids can be synthesized by combining known synthesizing methods.
Some compounds having the above structures are commercially
available. As a matter of course, not only the compounds prepared
by the known synthesizing methods but also the commercially
available compounds can be used as the electro-sensitive movable
fluid of the invention. These compounds can be used after purified,
if desired.
[0162] To the above-mentioned compounds, a small amount of
hydrocarbon compounds having 5 to 10 carbon atoms can be added to
give mixtures employable as the electro-sensitive movable fluids of
the invention. When the mixture containing a small amount of a
hydrocarbon compound of 5 to 10 carbon atoms is used as the
electro-sensitive movable fluid, the electric sensitivity of the
movable fluid can be improved.
[0163] Examples of the hydrocarbon compounds of 5 to 10 carbon
atoms include petroleum benzine, ligroin, hexane, pentane,
cyclopentane, cyclohexane and benzene. It is particularly
preferable to use petroleum benzine and ligroin singly or in
combination. The petroleum benzine is defined by JIS K 8594 and is
a hydrocarbon fraction of 5 to 8 carbon atoms having a distillation
temperature of 50 to 80.degree. C. The ligroin is defined by JIS K
8937 and is a hydrocarbon fraction of 5 to 9 carbon atoms having a
distillation temperature of 80 to 110.degree. C.
[0164] The hydrocarbon compound of 5 to 10 carbon atoms is added to
the electro-sensitive movable fluid in an amount of usually 0.1 to
20% by weight, preferably 1 to 10% by weight. However, mixing of
those compounds may cause decrease of the specific gravity of the
electro-sensitive movable fluid or increase of the current value,
so that the mixing ratio can be adjusted according to the use
purpose. The total amount of the hydrocarbon compound of 5 to 10
carbon atoms and the compound exhibiting electric sensitivity is
100% by weight.
[0165] To the electro-sensitive movable fluid of the invention,
various additives, such as metallic powders, substances to
ascertain stability of the movable fluid, colorants for color
development (e.g., dyes and pigments), viscosity modifiers to
modify viscosity of the movable fluid, can be added. Further,
biocides agents, mildewcides, solvents, etc. can be also added.
[0166] When a direct-current-voltage is applied to the
electro-sensitive movable fluid of the invention, jet flow of the
movable fluid corresponding to the applied direct-current-voltage
is formed.
[0167] For example, when the electro-sensitive movable fluid of the
invention having a conductivity and a viscosity located inside the
triangle formed by the points P, Q and R in FIG. 1, preferably
having a structure represented by the above formula, is introduced
in a container provided with electrodes shown in FIG. 5 and a
direct-current-voltage is applied, such jet flows of the
electro-sensitive movable fluid as shown in FIG. 5 are produced.
Therefore, if a vane rotor is equipped in the container, convection
of the electro-sensitive movable fluid collides with vanes of the
rotor to thereby rotate the rotor. That is, the electric energy
supplied to the electro-sensitive movable fluid of the invention is
converted to kinetic energy of fluid (i.e., jet flow of the movable
fluid), and the kinetic energy is captured and taken out. Thus, the
electric energy can be transformed to mechanical energy through the
electro-sensitive movable fluid.
[0168] The electro-sensitive movable fluid of the invention can be
used for fluid control device (fluidics). The fluidics have a
function to convert an electric-signal to a fluid-signal, so that
they can be applied to, as it is called, fluid-computer. In the
fluidics using the electro-sensitive movable fluid of the
invention, as shown in FIG. 6(A), electrodes 65, 66, 67 are
arranged in a main tube 61 of a fluid transport tube having plural
branch tubes 62a, 62b, . . . Of the electrodes, the electrode 65 is
grounded to make it a negative electrode, while the electrode 66 is
set to be a positive electrode. Then, a voltage is applied to the
positive electrode. If a jet flow of the electro-sensitive movable
fluid is given in the upward direction inside the main tube 61, a
force to move the electro-sensitive movable fluid in the direction
of the electrode 66 to the electrode 65 is generated. This force
acts to push the upward jet flow in the transverse direction,
whereby the jet flow is led to the branch tube 62b. To the
contrary, when the electrode 67 is set to be a positive electrode
and a voltage is applied thereto, the jet flow can be led to the
branch tube 62a. Thus, the electric signals between the electrodes
can be converted to the kinetic signals of fluid.
[0169] As shown in FIG. 6(B), if the positions of the electrodes in
the fluidics are varied so that the electrode 69 is set to be a
positive electrode and that change-over of the negative electrode
(ground point) between the electrode 68a and the electrode 68b is
made possible, a jet flow of the electro-sensitive movable fluid is
formed and the direction of the jet flow can be controlled by
performing change-over of the earth point (68a, 68b). Thus, the
electric signals between the electrodes can be converted to the
kinetic signals of fluid.
[0170] In FIG. 2, an embodiment of an apparatus (SE type ECF motor)
to convert the electric energy to the mechanical energy using the
electro-sensitive movable fluid is shown, and an embodiment of
arrangement of the electrodes in the SE type ECF motor is also
shown. In FIG. 3, an embodiment of a RE type ECF motor and an
embodiment of arrangement of the electrodes in the RE type ECF
motor are shown.
[0171] Referring to FIG. 2, the SE type ECF motor 1 comprises a
container 2 (bottomed cylindrical fluid container) to be filled
with an electro-sensitive movable fluid 22, a lid 4 of the fluid
container 2, and a vane rotor 18 provided with vanes 6 which detect
motion of the movable fluid 22 caused by application of a voltage
to rotate the rotor. The upper rim of the bottomed cylindrical
fluid container 2 is provided with slits 13 for disposing
electrodes 3a . . . 3h therein. In the fluid container 2, fixing
parts 14, 15 are provided to fix the electrodes 3a . . . 3h drawn
inside through the slits onto the inner wall surface of the fluid
container.
[0172] The center of the lid 4 is provided with a shaft hole 19
through which a rotating shaft of the vane rotor 18 penetrates. The
vane rotor 18 comprises a bearing 23 provided at the center of the
bottom of the fluid container and plural vanes 6 combined with the
rotating shaft which is rotatably borne by the shaft hole.
[0173] The electrodes 3a . . . 3h are drawn inside the fluid
container 2 through the slits 13 and extend toward the bottom of
the fluid container 2 along the inner wall surface of the fluid
container 2 so that the rotation of the vane rotor 18 is not
hindered. The electrodes 3a . . . 3h are insulated from each
other.
[0174] The electro-sensitive movable fluid 22 is filled in the
fluid container 2 in such an amount that the movable fluid does not
overflow the slits 13 and that the most parts of the vanes 6 are
immersed in the movable fluid. Then, a direct-current-voltage is
applied to the electrodes 3a . . . 3h. The rotational direction of
the vane rotor 18 can be controlled by the arrangement of positive
electrodes and negative electrodes.
[0175] For example, when the electrodes 3a, 3e are set to be
positive electrodes, the electrodes 3b, 3f are set to be negative
electrodes, and the electrodes 3c, 3d, 3g and 3h are set to be
dummy electrodes, a jet flow in the direction of the electrode 3a
to the electrode 3b or a jet flow in the direction of the electrode
3e to the electrode 3f dominates. Consequently, the rotational
direction of the vane rotor 18 can be made clockwise as shown by
arrows in FIG. 2.
[0176] The voltage and the current applied to n of the electrodes
represented by 3a to 3h . . . can be successively varied with time
(variable application method). In the variable application method,
the applied voltage can be made low. Hence, this method is very
useful in the case where a high voltage is unable to be used or a
large-sized apparatus needs to be used.
[0177] The motor in which the electrodes 3a . . . 3h are fixed to
the inner wall surface of the fluid container 2 is referred to
herein as "SE type ECF motor (stator-electrode type
electro-conjugate fluid motor)".
[0178] For example, a vane rotor 18 having eight vanes 6 is
disposed inside the cylindrical fluid container 2, and the fluid
container 2 is filled with the electro-sensitive movable fluid to
fabricate a SE type ECF motor shown in FIG. 2. When a
direct-current-voltage is applied between the electrodes 3a . . .
3h arranged shown in FIG. 2, the vane rotor 18 begins to rotate. As
the number of the vanes 6 is increased, the rotational speed of the
vane rotor 18 tends to be increased. As the interval of the
electrodes is narrowed, or as the number of pairs of the electrodes
is increased, the rotational speed tends to be increased. The
rotational speed of the vane rotor 18 is increased or decreased in
proportion to the applied voltage during the time from the initial
rotation to the stable rotation.
[0179] The electro-sensitive movable fluid of the invention is able
to convert the electric energy to the mechanical energy using the
below-described RE type ECF motor in place of the SE type ECF
motor.
[0180] FIG. 3 is a perspective view schematically showing another
embodiment (RE type ECF motor) of the motor using the
electro-sensitive movable fluid. In FIG. 3, an embodiment of
arrangement of the electrodes in the RE type ECF motor is also
shown.
[0181] Referring to FIG. 3, the motor (RE type ECF motor) 40 for
electro-sensitive movable fluid comprises a container 41 (bottomed
fluid container) to be filled with an electro-sensitive movable
fluid 22 and a lid 44 which is engaged with the open top to close
the fluid container 41. When the lid 44 is engaged with the upper
open part of the fluid container 41, the lid 44 and the fluid
container 41 construct together a closed housing.
[0182] The fluid container 41 for constituting the housing has a
bottom and is generally made of a material which is corrosion
resistant to the electro-sensitive movable fluid filled therein.
Examples of such materials include synthetic resins, such as
Teflon, polycarbonate and acrylic resins, ceramics, woods, metals
and glasses. The fluid container 41 can be formed from a conductive
material such as metal (e.g., stainless steel). The fluid container
41 formed from such a conductive material is preferably subjected
to electrical insulation treatment or the fluid container 41 is
preferably formed from an insulating material so as not to mar the
insulated state between the electrodes.
[0183] The center of the bottom 49 of the fluid container 41 is
provided with a bearing section 48. Owing to the bearing section
48, the lower end of a rotating shaft 45 is borne. The bearing
section 48 forms a rotational contact point 60 for electrically
connecting the second external terminals 52 and the second
electrodes 42 with each other. From the rotational contact point
60, conductors are led out along the inner wall surface of the
fluid container 41. The conductors led out of the housing form the
second external terminals 52. At the bearing section 48 which forms
the rotational contact point 60 and bear the lower end of a
rotating shaft 45, a bearing mechanism can be provided to reduce
coefficient of friction between the bearing section 48 and the
rotating shaft 45.
[0184] The top of the fluid container 41 is open to fill the
container with the electro-sensitive movable fluid 22.
[0185] After the fluid container 41 is filled with the electricity
movable fluid 22, the lid 44 is engaged with the open top of the
fluid container 41 to form a closed housing. The lid 44 can be
formed from the same material as for the fluid container 41.
[0186] The lid 44 has a shaft hole 47 at the center thereof,
through which the rotating shaft 45 penetrates. The rotating shaft
47 is provided with a rotational contact point 50 for supplying
electricity to the first electrodes 43 through the rotating shaft
45. At the rotational contact point 50, a bearing mechanism can be
provided to reduce friction between the rotating shaft 45 and the
shaft hole 47. From the rotational contact point 50, conductors are
led out to form the first external terminals 53. As the conductors
of the rotational points 50, 60, mercury is employable.
[0187] In FIG. 3, the lid 44 is designed so as to be engaged with
the fluid container 41, but the fluid container 41 and the lid 44
may be designed so that they are screwed up in order to improve the
enclosed state, or packing or the like can be interposed between
the fluid container 41 and the lid 44 to improve the enclosed
state.
[0188] The rotational shaft 45 is divided into the upper part and
the lower part by a cylindrical rotor 46 disposed in the fluid
container 41, and the upper rotating shaft 45a and the lower
rotating shaft 45b are electrically insulated from each other. The
upper rotating shaft 45a penetrates through the shaft hole 47
provided at the center of the lid 44 and is rotatably borne by the
shaft hole, while the lower rotating shaft 45b is rotatably borne
by the bearing section 48 provided at the center of the bottom 49
of the fluid container 41. Between the upper rotating shaft 45a an
the lower rotating shaft 45b, the cylindrical rotor 46, which
rotates together with the rotating shaft 45 in the fluid container
41, is disposed. This cylindrical rotor 46 is in the form of a
cylinder having the rotating shaft 45 as a center axis of the
rotation and is disposed in such a manner that space is formed
between the rotor 46 and the fluid container 41 so that the rotor
46 is not brought into contact with the inner wall surface of the
container 41. The ratio of the inner diameter of the fluid
container 41 to the diameter of the cylindrical rotor 46 (inner
diameter of fluid container 41/diameter of rotor 46) is usually not
less than 1.01, preferably 1.05 to 10.0. When the motor is
miniaturized by setting the inner diameter of the fluid container
41 to not more than 30 mm and setting the ratio of the inner
diameter of the fluid container 41 to the diameter of the
cylindrical rotor 46 within the range of 1.5 to 3.0, the rotational
torque is increased at the same rotational speed. In other words,
this motor (RE type ECF motor) is characterized in that the
performance can be improved by being miniaturized.
[0189] The shape of the rotor 46 is not limited to a cylindrical
one, and various shapes such as a rectangular parallelepiped shape,
a shape having a number of protrusions on the surface and a shape
having star-like section are employable according to the use
purpose. The cylindrical rotor 46 may be hollow. In this case, the
hollow portion may be made vacuum or may be filled with air, gas,
liquid or solid so that the weight of the rotor is able to be
optionally adjusted. By adjusting the weight of the cylindrical
rotor 46, the specific gravity of the rotor 46 in the
electro-sensitive movable fluid can be adjusted, whereby motion or
balance of the rotor 46 can be controlled.
[0190] On the surface of the cylindrical rotor 46, the first
electrodes 43 and the second electrodes 42 are arranged. The first
electrodes 43 are connected with the external terminals 53 through
the upper rotating shaft 45a and the rotational contact point 50.
The second electrodes 42 are connected with the external terminals
52 through the lower rotating shaft 45b and the rotational contact
point 60. The first electrodes 43 are electrically insulated from
the second electrodes 42.
[0191] The first electrodes 43 and the second electrodes 42 can be
formed by extending conductors on the cylindrical surface of the
cylindrical rotor 46.
[0192] The first electrodes 43 and the second electrodes 42 can be
arranged at appropriate positions. FIG. 3 shows an embodiment of
arrangement of the electrodes when the cylindrical rotor 46 is seen
from above. The first electrodes 43 and the second electrodes 42
are arranged in such a manner that the interval angle .theta.
between the first electrode 43 and the second electrode 42 is
usually 1.0.degree. to 180.degree., preferably 3.0.degree. to
90.0.degree.. The interval angle .theta. varies depending on the
number of the electrodes arranged. Therefore, in order to set the
interval angle .theta. within the above range, the number of the
first electrodes 43 and the number of the second electrodes 42 are
each 1 to 60. In FIG. 3, the number 46 represents a cylindrical
rotor, and the number 53a represents a conductor led out from the
first electrode 43, and this conductor may be incorporated into the
upper rotating shaft 45a. Alternatively, the conductor and the
upper rotating shaft 45a may be united into one body by forming the
upper rotating shaft 45a itself from a conductive material.
[0193] Likewise, a conductor 52a is lead out from the second
electrode 42, and this conductor may be incorporated into the lower
rotating shaft 45b. Alternatively, the conductor and the lower
rotating shaft 45b may be united into one body by forming the lower
rotating shaft 45b itself from a conductive material.
[0194] The fluid container 41 having the above-described structure
is filled with the electro-sensitive movable fluid 22.
[0195] The motor in which the electrodes are arranged on the
surface of the cylindrical rotor 46 is referred to herein as "RE
type ECF motor (rotor-electrode type electro-conjugate fluid
motor)".
[0196] In FIG. 3, an embodiment of the RE type ECF motor wherein
the cylindrical rotor 46 formed from a column-like material is
disposed in the fluid container 41 is shown. On the top of the
cylindrical rotor 46, the rotating shaft 45a made of, for example,
a metallic round bar is provided.
[0197] A plus terminal and a minus terminal of a direct current
power source are connected with the external terminal 52 and the
external terminal 53, respectively, so that the
direct-current-voltage can be applied between the first electrode
43 and the second electrode 42 of the RE type ECF motor. One of the
first electrode 43 and the second electrode 42 is set to be a
positive electrode and the other is set to be a negative electrode,
and in this case, any one of them may be set to be a positive
electrode. When the direct-current-voltage is applied, the
electro-sensitive movable fluid 22 begins to flow. With the flow
(jet flow) of the electro-sensitive movable fluid 22, the
cylindrical rotor 46 begins to rotate. The current generated when
the direct-current-voltage is applied is very small, usually not
more than 0.5 mA, in many cases not more than 20 .mu.A because the
electro-sensitive movable fluid used in the invention is
substantially nonconductive.
[0198] By applying a direct-current-voltage to the
electro-sensitive movable fluid of the invention filled in the SE
type ECF motor or the RE type ECF motor having the above structure,
the SE type ECF motor or the RE type ECF motor can be driven.
[0199] Next, a method of driving, for example, the SE type ECF
motor by the use of the electro-sensitive movable fluid of the
invention is explained. This motor is so fabricated that the motor
comprises a plastic vane rotor having eight vanes and a plastic
fluid container of 10 mm in outer diameter, 8 mm in inner diameter
and 20 mm in height, and that four pairs of electrodes made of
copper wire of 0.3 .mu.m in diameter are arranged on the inner
surface of the fluid container. This SE type ECF motor is filled
with the electro-sensitive movable fluid and then driven. The
rotational speed of the SE type ECF motor, the applied voltage and
the current can be measured in the following manner. As for the
rotational speed, a plastic disc is fitted to the rotating shaft of
the SE type ECF motor as shown in FIG. 4(a). The rotation of the
plastic disc is detected by a photo interrupter to measure the
rotational speed of the SE type ECF motor. As for the current,
series resistance of 1 M.OMEGA. is inserted between the SE type ECF
motor and the ground as shown in FIG. 4(b). From the potential
difference caused by the resistance, the current can be measured.
As for the voltage, Zener diode is connected in parallel with the
resistance, and the voltage can be measured through a voltage
follower using an OP amplifier having sufficiently high input
impedance.
[0200] For example, a direct-current-voltage of usually 0.1 V to 10
kV, preferably 10 V to 7.0 kV, is applied to the electro-sensitive
movable fluid of the invention filled in the above-mentioned
apparatus. In this case, the current is usually 0.001 to 100 .mu.A,
preferably 0.05 to 10.0 .mu.A, and therefore the power supplied to
the SE type ECF motor or the RE type ECF motor (i.e., between the
electrodes) is 1.times.10.sup.-10 to 1.0 W, preferably
5.times.10.sup.-7 to 7.times.10.sup.-2 W.
[0201] The applied voltage can be appropriately varied depending on
scale of the apparatus, kind of the electro-sensitive movable fluid
of the invention, construction of the apparatus, etc., but with the
proviso that the same apparatus and the same fluid are used under
the same conditions, the rotational speed varies in proportion to
the applied voltage.
[0202] In FIG. 7, an example of a relation between the applied
voltage and the rotational speed and an example of a relation
between the applied voltage and the current are shown. That is,
FIG. 7 shows a relation between the applied voltage and the
rotational speed and a relation between the current and the
rotational speed given when a voltage up to 6 kV is applied to the
SE type ECF motor. As shown in FIG. 7, there are constant
proportional relations between the applied voltage and the
rotational speed and between the applied voltage and the
current.
[0203] The control of the rotational speed owing to the control of
the voltage can be performed also in the RE type ECF motor using
the electro-sensitive movable fluid as well as in the SE type ECF
motor.
[0204] The mechanism of driving the SE type ECF motor or the RE
type ECF motor by the use of the electro-sensitive movable fluid of
the invention has not been clarified yet. However, such jet flows
as shown in FIG. 5 are confirmed to be produced when a voltage is
applied to the electro-sensitive movable fluid, and it is
considered that the jet flows become a rotational propulsion force
of the motor.
[0205] Periodically, the motors driven in high electric fields by
the use of dielectric fluids have attracted the attention of
scientists, and some reports have been made. For example, more than
40 years ago, there was a report that a glass bar having a diameter
of a few mm placed between parallel plate electrodes, which were
immersed in a dielectric fluid, began to rotate at a few thousands
rpm upon application of about 10 kV. The explanation for occurrence
of this phenomenon is as follows. The charge generated on the glass
bar surface is attracted by the electrode of the opposite polarity
to slightly rotate the glass bar, at this instant the polarization
disappears, and the repetition of attraction of the charge and
disappearance of the polarization results in occurrence of constant
rotation. In this explanation, there is no direct relation between
the conductivity of the fluid and the rotary motion of the glass
bar. The motor utilizing the above phenomenon is of about a few mm,
and it is not reported that a large motor such as the SE type ECF
motor or the RE type ECF motor is able to be rotated.
[0206] The above theory cannot explain the mechanism of converting
electric energy to mechanical energy through the SE type ECF motor
or the RE type ECF motor using the electro-sensitive movable fluid
of the invention, because the conductivity and the viscosity of the
electro-sensitive movable fluid are very important factors of the
drive of the motor in the invention.
[0207] The mechanism of converting the electric energy to the
mechanical energy through the SE type ECF motor or the RE type ECF
motor of the invention is investigated below based on the matters
having been already confirmed.
[0208] The ionic mobility has been reported to be of the order of
10.sup.-8 m.sup.2V.sup.-1S.sup.-1 in a fluid having a viscosity of
a few mPa.multidot.s. Assuming that the hydrodynamic radius of ions
is within the range of 0.5 to 1.2 nm, the ionic mobility can be
estimated, through the Stokes-Einstein equation, as
5.times.10.sup.-3 m/s in an electric field of 0.5 kVmm.sup.-1 (5 kV
applied between electrodes at an interval of 10 mm). Also, assuming
that the ionic motion directly brings about drag flow of the fluid
to thereby rotate the motor, the rotational speed may be much
slower. Because the SE type ECF motor and the RE type ECF motor
rotate at a higher speed by two figures as much as the
above-assumed rotational speed, it is difficult to infer that the
ionic motion directly brings about a rotary motion of the rotor.
When a high voltage is applied to a dielectric fluid as described
above, a secondary motion of fluid such as convection or chaos is
sometimes brought about. According to the computing simulation on
the electrohydrodynamic (EHD) convection under such conditions that
the gravitational effect is negligibly small (microgravity
conditions), the velocity of the secondary flow is assumed to be
about 0.02 m/s at an electric Rayleigh number of 6,000 where the
Coulomb force is much larger than the viscous force. However, this
value is a little smaller than the flow velocity observed when the
electro-sensitive movable fluid of the invention is used, so that
the mechanism of the high speed rotation of the rotor cannot be
completely explained by only the EHD convection. The EHD convection
referred to herein is a non-linear phenomenon controlled by
continuous equation, kinetic equation, Maxwell equation and charge
transfer equation.
[0209] Yabe and Maki have found that when a high voltage of 10 kV
is applied to a ring electrode and a plate electrode arranged
axisymmetrically, a jet flow of fluid is created in the vicinity of
the center of the ring in the direction away from the plate
electrode, and they made a report on the findings (see: Int. J.
Heat Mass Transfer 31, 407 (1988)). It has been reported that the
above phenomenon is such a phenomenon that the fluid attracted from
the circumference of the ring is jetted after the fluid passed
through gap between the ring and the plate electrode, and the flow
velocity sometimes exceeds 1 m/s. The mechanism of occurrence of
the jet flow is not clear, but the velocity of the jet flow is
comparable to the circumferential velocity of the rotor in the
invention. Since the velocity of the jet flow seems to be similar
to that of the electro-sensitive movable fluid when a
direct-current-voltage is applied to the movable fluid, those
mechanism may have some relevancy each other. However, the above
fluid composition (flon R113 +ethanol) shows quite different from
the movable fluid of the invention, and the above apparatus is also
different from that of the invention. For reasons, the relevancy is
still unknown.
[0210] The description on the mechanism of the present invention is
just an inference which is made by the present inventors based on
the confirmed facts and which is intended to assist understanding
of the present invention. Therefore, it should be construed that
the invention is not limited to the inference.
[0211] The electro-sensitive movable fluid of the invention flows
upon application of a direct-current-voltage. The jet flow of the
movable fluid can be converted to mechanical energy such as
rotational energy and can be taken out as the mechanical energy.
Further, when the voltage applied to the electro-sensitive movable
fluid of the invention is changed to vary the supplied electric
energy, the electric energy can be converted to energy of other
form in proportion to the amount of the electric energy supplied by
the applied voltage, with stepless controlling the voltage.
Accordingly, the electro-sensitive movable fluid of the invention
can be used in various fields, for example, a field utilizing the
motion of the electro-sensitive movable fluid between the
electrodes applied with a direct-current-voltage and a field
utilizing the rotational energy which is converted from the jet
flow motion of the electro-sensitive movable fluid produced by
application of a direct-current-voltage and then taken out of the
apparatus. The SE type ECF motor and the RE type ECF motor are
typical embodiments. The SE type ECF motor and the RE type ECF
motor utilizing the energy conversion control method of the
invention is improved in the performance when they are
miniaturized. Besides, these motors have simple structures, so that
they are very effective as inexpensive, trouble-free
micromotors.
[0212] As described above, the electro-sensitive movable fluid can
be utilized for the rotary mechanism in which the rotor equipped
with electrodes is rotated. Further, if a small fragment equipped
with electrodes is placed in the electro-sensitive movable fluid
and a direct-current-voltage is applied to the electrodes from the
outside, the small fragment is able to freely swim like fish in the
movable fluid owing to a propulsion force supplied by the fluid jet
flow produced between the electrodes.
[0213] Furthermore, if a small fragment equipped with electrodes on
its bottom surface is floated on the electro-sensitive movable
fluid of the invention and a direct-current-voltage is applied to
the electrodes, the small fragment is able to freely sail like a
boat on the movable fluid surface owing to a propulsion force of
the fluid jet flow.
[0214] Instead of application of the direct-current-voltage from
the external electric source, the direct-current-voltage can be
directly applied by means of solar panel, light piezoelectric
element or PLZT element capable of generating high voltage by
irradiation with light. In this case, the solar panel or the PLZT
element is fitted to the driving section together with the
electrodes and irradiated with light instead of applying a voltage
from the external electric source, whereby no wire from the
external electric source is necessary. As a result, the above
fragment (fragment moving like fish or boat) has a high degree of
freedom in its motion, and even in a transparent closed container,
the motion of the fragment can be controlled without restraint. In
other words, for an innter work where human beings cannot get into,
e.g., atomic power station, the system using the electro-sensitive
movable fluid of the invention can be used as an inner work
apparatus capable of being driven and controlled by irradiation
with light through protective glass; therefore, it is very
useful.
[0215] In the field of computer technology, a great number of
semiconductors are used for computers. When the computers are
driven, the semiconductors generate heat. Therefore, most of the
computers needs to be equipped with built-in fans to cool the
computers. The cooling fans generally use electromagnetic motors,
and such cooling fans generate heat during working. Consequently,
the cooling fans must cool not only the semiconductor chips which
generate heat during working but also the electromagnetic motors
which drive the fans, resulting in large power consumption.
Moreover, the size of the electromagnetic motors is large for the
size of the semiconductor chips, and this is an obstacle to
miniaturization of computer or conservation of energy. On the other
hand, the ECF cooling fans using the electro-sensitive movable
fluid, which comprise motors fabricated based on the technique of
the invention and cooling vanes, hardly generate heat. Besides,
they can be driven by a low power and can be miniaturized.
Therefore, the ECF cooling fans are most suitable for small
computers. In addition, miniaturization of the motors makes it
possible to equip the cooling fan for every semiconductor which
generates heat. That is, on-chip type cooling fans are
employable.
[0216] In another use, a linear motor capable of being driven by a
linear jet flow of the electro-sensitive movable fluid is available
by using a rectangular parallelepiped fluid container in place of
the cylindrical fluid container and arranging electrodes on the
inner surface of the container. As another mechanism, a linear
motor using the above-mentioned fish-like fragment provided with
electrodes can be constructed.
[0217] The electro-sensitive movable fluid of the invention is
specified by the conductivity and the viscosity at a temperature at
which the movable fluid is used, and therefore the fluid may be
either of an organic compound and an inorganic compound.
Accordingly, the electro-sensitive movable fluid of the invention
also includes high-temperature inorganic fluids having the
prescribed conductivity and viscosity, such as lava extruded from
volcanoes (lava flow). If the high-temperature inorganic fluids
such as lava flow have the viscosity and conductivity defined by
the present invention, those fluids exhibit behaviors equivalent to
those of the electro-sensitive movable fluid of the invention.
Hence, if the lave flow satisfying the requisite of the
electro-sensitive movable fluid of the invention were provided with
huge electrodes and a direct-current-voltage were applied to the
electrodes, it might be feasible to control a path of the lava flow
(direction of the lave flow) by the applied
direct-current-voltage.
[0218] Since the electro-sensitive movable fluid of the invention
can be specified by the viscosity and the conductivity at the
working temperature as described above, driving of motors is
feasible by application of a direct-current-voltage even in the
extremely high-temperature environment where the conventional
motors are difficult to use, provided that the viscosity and the
conductivity of the fluids used for the motors are within the
above-defined range.
EFFECT OF THE INVENTION
[0219] The properties required for the electro-sensitive movable
fluid of the invention and the ranges of the properties are
specified by the present inventors. That is, the properties
required for the electro-sensitive movable fluid of the invention
are viscosity and conductivity at a temperature at which the
movable fluid is used, and no phenomenon suggesting participation
of other properties has not been found. The temperature is a mere
condition to specify the conductivity and the viscosity in the use
of the electro-sensitive movable fluid.
[0220] Accordingly, the requisite of the electro-sensitive movable
fluid of the invention is only that the fluid satisfies the
above-defined conductivity and viscosity, irrespective of an
organic or inorganic compound. That is, the present invention gets
out of the preconceived ideas that electro-sensitive movable fluids
are organic compounds and thereby extends a possibility of using
the inorganic compounds as the electro-sensitive movable
fluids.
[0221] When a direct-current-voltage is applied to the
electro-sensitive movable fluid of the invention provided with
positive and negative electrodes, the movable fluid moves between
the electrodes. In other words, the electro-sensitive movable fluid
of the invention moves between the electrodes by mere application
of a direct-current-voltage without using any physical actuation
means such as pump. Therefore, the electric energy can be directly
converted to kinetic energy by the use of the electro-sensitive
movable fluid of the invention.
[0222] Owing to the movement of the electro-sensitive movable
fluid, a continuous, constant and systematic motion of the movable
fluid, such as convection of the fluid, can be formed in the
container.
[0223] By taking the continuous, constant and systematic motion of
the movable fluid out of the container in the form of, for example,
rotational energy, the electric energy can be transformed to clean
and quiet kinetic energy.
[0224] Further, the conversion of the electric energy to the
kinetic energy is performed by mere applying a
direct-current-voltage to a specific single material, so that it is
unnecessary to mix plural compounds to prepare a fluid.
Furthermore, the electric sensitivity is determined by the
properties inherent in the single compound, variability in the
electric sensitivity, which may be caused by the mixing ratio in
the case of using mixtures, is small.
[0225] Since the electro-sensitive movable fluid of the invention
is a stable ester compound, it is quite safe to the human body.
Moreover, since the movable fluid substantially contains no halogen
atoms, environmental pollution of the earth-caused by the halogen
atoms does not brought about.
[0226] By the use of the electro-sensitive movable fluid of the
invention, an extremely small sized actuator can be manufactured,
and because of its simple internal structure, the actuator is
almost free from troubles.
[0227] The electro-sensitive movable fluid of the invention works
upon application of a direct-current-voltage as described above,
and the current is very low under those conditions. Hence, the SE
type ECF motor or the RE type ECF motor using the electro-sensitive
movable fluid of the invention can be driven for a long period of
time by means of small-sized batteries. In addition, these motors
have simple structures, they are almost free from troubles, and
they are able to convert the electric energy to the kinetic energy
at low costs.
[0228] Production of a jet flow of the electro-sensitive movable
fluid of the invention upon application of a voltage means that the
applied electric energy is directly converted to the kinetic
energy. Therefore, if a fluid begins to flow upon application of a
voltage, this fluid is an electro-sensitive movable fluid. A fluid,
which shows a high flow velocity when the applied voltage is made
constant, is an electro-sensitive movable fluid capable of
preferably converting the electric energy to the kinetic
energy.
[0229] Furthermore, since the jet flow of the electro-sensitive
movable fluid of the invention can be produced when an electric
field is formed, the movable fluid can be applied to the
above-mentioned various uses.
EXAMPLE
[0230] The present invention will be further described with
reference to the following examples, but it should be construed
that the invention is in no way limited to those examples.
Example 1
[0231] The compounds (1) to (36) listed below were measured on the
viscosity and the electric resistance (conductivity) at 25.degree.
C. Measurement of the viscosity and the electric resistance was
performed by the use of a rheometer (Rheo-Stress RS100 of HAAKE
Co.). In detail, the compound was sandwiched between two discs each
having a diameter of 3.5 cm, and thereto was applied a
direct-current-voltage of 2 kV to measure the conductivity (S/m
upon application of 2 kV/mm). In the same state, the viscosity of
the compound was measured with rotating one of the discs. The
values of the conductivity and the viscosity referred to in herein
are those determined by the above methods.
[0232] The compound was filled in such a SE type ECF motor as shown
in FIG. 2. Then, a direct-current-voltage of 6 kV was applied to
the compound at 25.degree. C. to examine whether the vane rotor
rotated or not and to measure the rotational speed when the rotor
rotated.
[0233] In the SE type ECF motor used herein, the inner diameter of
the bottomed cylindrical container was 20 mm, the number of vanes
was 8, and each vane had a height of 35 mm and a width of 17 mm.
When 12 ml of the movable fluid was introduced into the container,
the vanes were completely immersed in the fluid.
[0234] The SE type ECF motor was provided with 4 electrodes. The
first and the third electrodes were set to be negative electrodes,
and the second and the fourth electrodes were set to be positive
electrodes. These four electrodes were arranged in such a manner
that the interval angle between the first and the third electrodes
and the interval angle between the second and the fourth electrodes
were each 180.degree. and the interval angle between the first and
the second electrodes and the interval angle between the third and
the fourth electrodes were each 45.degree..
[0235] Into the SE type ECF motor having the above structure, 12 ml
of the fluid was introduced, and a direct-current-voltage of 6 kV
was applied between the electrodes to examine whether the SE type
ECF motor was driven or not and to measure the rotational speed
when the motor was driven. The conductivity, the viscosity and the
electric sensitivity of the dielectric fluids used are set forth in
Table 3.
2TABLE 3 Compound Conduc- Viscosity Electric Sensitivity
(.TM.:trademark) tivity (S/m) (Pa .multidot. s) (6 kV) (I) (1) DBA
3.01 .times. 10.sup.-9 3.5 .times. 10.sup.-3 .diamond-solid.driven
at 147 rpm (2) TBC 5.71 .times. 10.sup.-7 2.0 .times. 10.sup.-2
.diamond.not driven (3) MBM 2.60 .times. 10.sup.-5 2.0 .times.
10.sup.-2 .diamond.not driven (4) DAM 7.80 .times. 10.sup.-7 2.5
.times. 10.sup.-3 .diamond.not driven (5) DMP 3.90 .times.
10.sup.-7 1.2 .times. 10.sup.-2 .diamond.not driven (6) Triacetin
.TM. 3.64 .times. 10.sup.-9 1.4 .times. 10.sup.-2
.diamond-solid.driven at 77 rpm (7) Ethyl cellosolve acetate 7.30
.times. 10.sup.-5 9.0 .times. 10.sup.-4 .diamond.not driven (8)
2-(2-Ethoxyethoxy) ethyl 6.24 .times. 10.sup.-7 1.4 .times.
10.sup.-2 .diamond.not driven acetate (9) 1,2-Diacetoxyethane 2.00
.times. 10.sup.-6 1.5 .times. 10.sup.-3 .diamond.not driven (10)
Triethylene glycol acetate 5.20 .times. 10.sup.-7 8.1 .times.
10.sup.-3 .diamond.not driven (11) Butyl cellosolve acetate 2.10
.times. 10.sup.-8 7.0 .times. 10.sup.-4 .diamond-solid.driven at
129 rpm (12) Butyl carbitol acetate 5.20 .times. 10.sup.-8 1.7
.times. 10.sup.-3 .diamond-solid.driven at 155 rpm (13) Solfit AC
.TM. 8.30 .times. 10.sup.-8 6.0 .times. 10.sup.-4
.diamond-solid.driven at 158 rpm (14) DBF 2.65 .times. 10.sup.-9
3.5 .times. 10.sup.-3 .diamond-solid.driven at 178 rpm (15)
Placizer B-8 .TM. 1.10 .times. 10.sup.-8 7.8 .times. 10.sup.-2
.diamond.not driven (17) PMA 1.56 .times. 10.sup.-7 6.0 .times.
10.sup.-4 .diamond-solid.driven at 162 rpm (18) MAR-N .TM. 1.30
.times. 10.sup.-8 1.3 .times. 10.sup.-2 .diamond-solid.driven at 53
rpm (19) Exepal EH-P .TM. 2.60 .times. 10.sup.-10 9.5 .times.
10.sup.-3 .diamond.not driven (20) DBI 1.46 .times. 10.sup.-8 3.5
.times. 10.sup.-3 .diamond-solid.driven at 167 rpm (21) Emanone
4110 .TM. 3.75 .times. 10.sup.-7 8.0 .times. 10.sup.-2 .diamond.not
driven (22) Exepal BS .TM. 3.10 .times. 10.sup.-10 8.5 .times.
10.sup.-3 .diamond.not driven (23) Kyowanol D .TM. 6.24 .times.
10.sup.-9 4.0 .times. 10.sup.-3 .diamond-solid.driven at 138 rpm
(24) Kyowanol M .TM. 6.80 .times. 10.sup.-8 1.2 .times. 10.sup.-2
.diamond.not driven (25) MP-Ethoxypropanol .TM. 6.24 .times.
10.sup.-5 8.0 .times. 10.sup.-4 .diamond.not driven (26)
BP-Ethoxypropyl Acetate .TM. 3.10 .times. 10.sup.-8 6.0 .times.
10.sup.-4 .diamond-solid.driven at 143 rpm (27) Sansocizer E-4030
.TM. 5.46 .times. 10.sup.-9 2.0 .times. 10.sup.-2
.diamond-solid.driven at 58 rpm (28) Sansocizer DOTP .TM. 6.20
.times. 10.sup.-10 4.0 .times. 10.sup.-2 .diamond-solid.driven at
35 rpm (29) TBP 2.20 .times. 10.sup.-6 2.2 .times. 10.sup.-3
.diamond.not driven (30) TBXP 1.10 .times. 10.sup.-5 9.0 .times.
10.sup.-3 .diamond.not driven (II) (31) CLP 7.80 .times. 10.sup.-6
3.0 .times. 10.sup.-2 .diamond.not driven (32) Ethyl
2-methylacetoacetate 1.00 .times. 10.sup.-4 5.0 .times. 10.sup.-4
.diamond.not driven (33) 1-Ethoxy-2-acetoxypropane 4.41 .times.
10.sup.-7 4.0 .times. 10.sup.-4 .diamond-solid.driven at 161 rpm
(34) DCM-40 .TM. 2.60 .times. 10.sup.-5 5.5 .times. 10.sup.-3
.diamond.not driven (35) Linalyl acetate 1.82 .times. 10.sup.-9 1.3
.times. 10.sup.-3 .diamond-solid.driven at 258 rpm (36) Dibutyl
decanedicate 1.40 .times. 10.sup.-9 7.0 .times. 10.sup.-3
.diamond-solid.driven at 132 rpm
[0236] The relation between the conductivity and the viscosity set
forth in table 3 is shown in FIG. 1, in which the conductivity and
the viscosity of the fluid which was driven are represented by
symbol .diamond-solid., and the conductivity and the viscosity of
the fluid which was not driven are represented by symbol
.diamond..
Example 2
[0237] The SE type ECF motor of Example 1 was filled with
2,2,4-trimethyl-1,3-pentanediol monoisobutyrate (compound (24),
trade name: Kyowanol M), and a direct-current-voltage of 6 kV was
applied. Since 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate had
a conductivity .sigma. of 6.80.times.10.sup.-8 S/m and a viscosity
.eta. of 1.2.times.10.sup.-2 Pa.multidot.s at 25.degree. C. as
shown in Tables 3 and 4, the SE type ECF motor was not driven.
[0238] Separately, the SE type ECF motor was filled with
2-ethylhexyl palmitate (compound (19), trade name: Exepal EH-P),
and a direct-current-voltage of 6 kV was applied. Since
2-ethylhexyl palmitate had a conductivity .sigma. of
2.60.times.10.sup.-10 S/m and a viscosity .eta. of
9.5.times.10.sup.-3 Pa.multidot.s at 25.degree. C. as shown in
Tables 3 and 4, the SE type ECF motor was not driven.
[0239] Then, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate
(compound (24), trade name: Kyowanol M) and 2-ethylhexyl palmitate
(compound (19), trade name: Exepal EH-P) were mixed in a mixing
ratio of 1:4 by weight to prepare a homogeneous mixture (37).
[0240] This mixture (37) was measured on the conductivity and the
viscosity in the same manner as in Example 1. As a result, the
mixture had a conductivity .sigma. of 2.60.times.10.sup.-9 S/m and
a viscosity .eta. of 9.8.times.10.sup.-3 Pa.multidot.s at
25.degree. C.
[0241] Then, the SE type ECF motor was filled with the mixture
(37), and a direct-current-voltage of 6 kV was applied at
25.degree. C. in the same manner as described above. As a result,
the motor was driven at 38 rpm.
[0242] The results are set forth in Table 4.
Example 3
[0243] The SE type ECF motor of Example 1 was filled with diallyl
maleate (DAM, compound (4)), and a direct-current-voltage of 6 kV
was applied. Since diallyl maleate had a conductivity .sigma. of
7.80.times.10.sup.-7 S/m and a viscosity .eta. of
2.5.times.10.sup.-3 Pa.multidot.s at 25.degree. C. as shown in
Tables 3 and 4, the SE type ECF motor was not driven.
[0244] Separately, the SE type ECF motor was filled with butyl
stearate (compound (22), trade name: Exepal BS), and a
direct-current-voltage of 6 kV was applied. Since butyl stearate
had a conductivity .sigma. of 3.10.times.10.sup.-10 S/m and a
viscosity .eta.of 8.5.times.10.sup.-3 Pa.multidot.s at 25.degree.
C. as shown in Tables 3 and 4, and the SE type ECF motor was not
driven.
[0245] Then, diallyl maleate (compound (4), DMA) and butyl stearate
(compound (22), trade name: Exepal BS) were mixed in a mixing ratio
of 1:4 by weight to prepare a homogeneous mixture (38).
[0246] This mixture (38) was measured on the conductivity and the
viscosity in the same manner as in Example 1. As a result, the
mixture had a conductivity .sigma. of 4.17.times.10.sup.-9 S/m and
a viscosity .eta. of 5.0.times.10.sup.-3 Pa.multidot.s at
25.degree. C.
[0247] Then, the SE type ECF motor was filled with the mixture
(38), and a direct-current-voltage of 6 kV was applied at
25.degree. C. in the same manner as described above. As a result,
the motor was driven at 140 rpm.
[0248] The results are set forth in Table 4.
3TABLE 4 Compound or Conduc- Visco- Electric Mixture tivity sity
Sensitivity ( .TM.: trademark) (S/m) (Pa .multidot. s) (6 kV) (24)
Kyowanol M .TM. 6.80 .times. 10.sup.-8 1.2 .times. 10.sup.-2
.diamond. (not driven) (19) Exepal EH-P .TM. 2.60 .times.
10.sup.-10 9.5 .times. 10.sup.-3 .diamond. (not driven) (37) (24) +
(19) 2.60 .times. 10.sup.-9 9.8 .times. 10.sup.-3 .diamond-solid.
(driven at 38 (24): (19) = 1:4 rpm) (4) DAM 7.80 .times. 10.sup.-7
2.5 .times. 10.sup.-3 .diamond. (not driven) (22) Exepal BS .TM.
3.10 .times. 10.sup.-10 8.5 .times. 10.sup.-3 .diamond. (not
driven) (38) (4) + (22) 4.17 .times. 10.sup.-9 5.0 .times.
10.sup.-3 .diamond-solid. (driven at 140 (4): (22) = 1:4 rpm)
[0249] The relation between the conductivity and the viscosity set
forth in Table 4 is shown in FIG. 1, in which the conductivity and
the viscosity of the fluid which was driven are represented by
symbol .diamond-solid., and the conductivity and the viscosity of
the fluid which was not driven are represented by symbol
.diamond..
Example 4
[0250] The SE type ECF motor of Example 1 was filled with
2-ethylhexyl benzyl phthalate (compound (15), trade name: Placizer
B-8), and a direct-current-voltage of 6 kV was applied with
maintaining the temperature of the 2-ethylhexyl benzyl phthalate at
25.degree. C. Since 2-ethylhexyl benzyl phthalate had a
conductivity .sigma. of 1.10.times.10.sup.-8 S/m and a viscosity
.eta. of 7.8.times.10.sup.-2 Pa.multidot.s at 25.degree. C. as
shown in Tables 3 and 5, the SE type ECF motor was not driven.
[0251] Then, 2-ethylhexyl benzyl phthalate (compound (15), trade
name: Placizer B-8) was heated to 100.degree. C. to obtain a heated
product (39). This heated product (39) was measured on the
conductivity and the viscosity at 100.degree. C. As a result, the
heated product had a conductivity .sigma. of 9.90.times.10.sup.-9
S/m and a viscosity .eta. of 3.5.times.10.sup.-3 Pa.multidot.s at
100.degree. C.
[0252] Then, a direct-current-voltage of bkV was applied in the
same manner as in Example 1, except that the SE type ECF motor was
filled with the heated product (39) and the temperature of the
product (2-ethylhexyl benzyl phthalate) was maintained at
100.degree. C. As a result, the motor was driven at 21 rpm.
[0253] The results are set forth in Table 5.
4TABLE 5 Compound or Conduc- Visco- Electric Mixture tivity sity
Sensitivity ( .TM.: trademark) (S/m) (Pa .multidot. s) (6 kV) (15)
Placizer B-8 .TM. 1.10 .times. 10.sup.-8 7.8 .times. 10.sup.-2
.diamond. (not driven) (25.degree. C.) (39) Placizer B-8 .TM. 9.90
.times. 10.sup.-9 3.5 .times. 10.sup.-2 .diamond-solid. (driven at
21 rpm) (100.degree. C.)
[0254] The relation between the conductivity and the viscosity set
forth in Table 5 is shown in FIG. 1, in which the conductivity and
the viscosity of the fluid which was driven are represented by
symbol .diamond-solid., and the conductivity and the viscosity of
the fluid which was not driven are represented by symbol
.diamond..
Example 5
[0255] A SE type ECF motor shown in FIG. 2 was fabricated, wherein
the fluid container made of an acrylic resin had an outer diameter
of 10 mm, an inner diameter of 8 mm and a height of 20 mm, and the
vane rotor had 8 vanes made of an acrylic resin. This SE type ECF
motor was provided with four pairs of electrodes each made of wire
having a diameter of 0.3 mm. The interval angle between the
electrodes was set to be 22.5.degree. (1.5 mm). The rotating shaft
of the vane rotor is made of wire having a diameter of 1 mm. As the
bearing, ball bearings were used to reduce friction torque. To the
rotating shaft, a plastic disc was fitted as shown in FIG. 4, and
the rotation of the disc was detected by means of a
photointerrupter to measure the rotational circumferential speed.
As shown in FIG. 4, a resistance of 1 M.OMEGA. was provided in
series between the SE type ECF motor and the ground to obtain a
current from the electric potential. In order to protect the
measuring device, Zener diode was connected in parallel with the
resistance, and the voltage was measured through a voltage follower
using an OP amplifier having sufficiently high input impedance.
[0256] The SE type ECF motor was filled with dibutyl decanedioate.
Then, a voltage was applied with varying the applied voltage by 1
kV in the range of 0 to 6 kV, to measure the rotational speed and
the current.
[0257] The SE type ECF motor began to rotate at the applied voltage
of 2 kV, and the rotational speed was increased in proportion to
the applied voltage.
[0258] The relation among the applied voltage, the rotational speed
and the current is shown in FIG. 7. As is clear from FIG. 7, the
rotational speed was increased in proportion to the applied
voltage.
Example 6
[0259] The SE type ECF motor shown in FIG. 2 was filled with
dibutyl decanedioate as the electro-sensitive movable fluid. Then,
a direct-current-voltage was applied between the electrodes with
varying the applied voltage to 2.5 kV, 3.0 kV, 3.5 kV, 4.0 kV, 4.5
kV, 5.0 kV, 5.5 kV and 6.0 kV, to measure the rotational speed of
the vane rotor. The results are shown in FIG. 8(a).
Example 7
[0260] In the SE type ECF motor shown in FIG. 2, dibutyl
decanedioate was used as the electro-sensitive movable fluid and
the number of vanes was varied to 2, 3, 4, 6 or 8. In each case,
the rotational speed of the vane rotor was measured (applied
voltage: 6 kV). The results are shown in FIG. 8(b). As the number
of vanes was increased, the rotational speed was increased. As the
interval between the electrodes was narrowed, the rotational speed
was increased. As the number of pairs of the electrodes was
increased, the rotational speed was increased. The rotational speed
was independent from the interval between the pairs of
electrodes.
Example 8
[0261] In the SE type ECF motor shown in FIG. 2, dibutyl
decanedioate was used as the electro-sensitive movable fluid, the
diameter of the fluid container was varied to 20 mm, and the
diameter of the vane rotor was varied to 6 mm, 13 mm or 17 mm. In
each case, the rotational speed and the output torque were
measured. For measuring the output torque, an apparatus shown in
FIG. 11 was used. The results are shown in FIG. 8(c).
[0262] Referring to FIG. 11, the number 30 represents a SE type ECF
motor or a RE type ECF motor, the number 31 represents a strain
gauge, the number 32 represents a micrometer, the number 33
represents a micrometer head, the number 34 represents a rotating
shaft, and the number 35 represents a wire. The wire 35 is spread
between two poles each fitted to the corresponding strain gauge 31
respectively, and is wound once on the rotating shaft 34. When the
rotating shaft 34 rotates, a difference of tension force of the
wire is produced. The difference of the tension force between the
right and left sides is measured by the strain gauge to determine
the output torque (rotational torque). That is, the load torque
given when the flexible wire 35 is wound once on the rotating shaft
34 of the SE type ECF motor is a friction torque (DF/2). The
difference of the tension force (T.sub.1-T.sub.2) of the wire 35 is
assumed to equal to the friction force F acted on the output shaft,
so that the output torque is calculated as
D(T.sub.1-T.sub.2)/2.
[0263] As is clear from FIG. 8(c), the vane rotor 18 was
efficiently rotated by the jet flow of dibutyl decanedioate, and
the electric energy was able to be transformed to rotational
energy. With increase of the rotational speed, the output torque
was reduced linearly. The current in the measurement of the output
torque was 2.2 .mu.A irrespective of the vane rotor diameter and
the output torque.
Example 9
[0264] In the SE type ECF motor shown in FIG. 2, dibutyl
decanedioate was used as the electro-sensitive movable fluid, and
the diameter of the fluid container and the diameter of the vane
rotor were varied to 12 mm and 9 mm, respectively, 16 mm and 13 mm
respectively, or 20 mm and 17 mm, respectively. In each case, the
rotational speed and the output torque were measured. The results
are shown in FIG. 8(d). When the ratio of the diameter of the vane
rotor 18 to that of the fluid container 2 was set to be constant
0.8, a higher output torque at the same rotational speed was
obtained with a smaller diameter of the fluid container 2. The
current was almost the same and the values thereof were 4.5 .mu.A
for 12 mm (fluid container diameter), 3.2 .mu.A for 16 mm, and 2.2
.mu.A for 20 mm. Based on the results shown in FIG. 8(d), when the
fluid container 2 having a diameter of 12 mm was used, the output
power was 0.30 mW and the energy conversion efficiency was 1.1%. It
was confirmed that when the ratio of the vane rotor diameter to the
fluid container diameter was constant, a higher output torque was
obtained with a smaller diameter of the fluid container. This
result suggests that the SE type ECF motor is suitable for
miniaturization.
[0265] From the output power obtained above, an output power
density to the volume of the motor was calculated. The volume of
the motor was calculated as a value of vane rotor
length.times.fluid container sectional area. The results are shown
in FIG. 9(a). As is clear from FIG. 9(a), the output power density
was remarkably improved by miniaturizing the SE type ECF motor.
Therefore, the SE type ECF motor is suitable for
miniaturization.
Example 10
[0266] In the RE type ECF motor shown in FIG. 3, dibutyl
decanedioate was used as the electro-sensitive movable fluid and
the interval angle between the rod type electrodes was varied to
11.degree., 23.degree. or 45.degree.. In each case, the rotational
speed and the output torque were measured. The results are set
forth in Table 9(b). The interval angle between the electrodes
hardly influenced the rotational speed of the cylindrical rotor 46.
That is, the characteristics of the RE type ECF motor are not
determined only by an equivalent electric field strength obtained
by dividing the voltage by the interval between the electrodes.
Assuming that the circumferential rate of the rotor with no-load is
almost equal to a flow rate of the dibutyl decanedioate, the
circumferential rate is about 120 mm/S, and this suggests that a
higher rotational speed may be obtained by miniaturizing the RE
type ECF motor.
Example 11
[0267] In the RE type ECF motor shown in FIG. 3, dibutyl
decanedioate was used as the electro-sensitive movable fluid, the
interval angle between the electrodes was set to be 23.degree., the
diameter of the cylindrical rotor was made to be 10 mm, and the
diameter of the fluid container was varied to 14 mm, 20 mm, 30 mm
or 40 mm. In each case, the rotational speed and the output torque
were measured. The results are set forth in FIG. 9(c). When the
diameter of the fluid container 41 was 14 mm, a high output torque
was obtained, but the rotational speed in the no-load state was
decreased. The reason is assumably that because of a narrow gap
between the fluid container 41 and the cylindrical rotor 46, the
jet flow of the dibutyl decadedioate is able to be efficiently
transformed to the rotary motion owing to the viscous force of the
fluid, while the loss of energy is increased because of the viscous
force, resulting in that a high rotational speed is not obtained
particularly in the no-load state.
Example 12
[0268] In the RE type ECF motor shown in FIG. 3, dibutyl
decanedioate was used as the electro-sensitive movable fluid, the
diameter of the fluid container and the diameter of the vane rotor
were varied to 14 mm and 10 mm, respectively, 20 mm and 16 mm
respectively, or 24 mm and 20 mm, respectively. In each case, the
rotational speed and the output torque were measured. The results
are shown in FIG. 9(d). With a smaller diameter of the fluid
container 41, the output torque at the same rotational speed was
increased and the change of the rotational speed for the load
torque was increased. Based on the results shown in FIG. 9(d), the
maximum value of the output power was 0.32 mW when the diameter of
the fluid container and the diameter of the cylindrical rotor of
the RE type ECF motor were 14 mm and 10 mm, respectively.
Example 13
[0269] In the SE type ECF motor shown in FIG. 2, dibutyl
decanedioate was used as the electro-sensitive movable fluid, and
the diameter of the fluid container and the diameter of the vane
rotor were varied to 14 mm and 10 mm, respectively, 20 mm and 16 mm
respectively, or 24 mm and 20 mm, respectively. In each case, the
rotational speed and the output torque were measured. The results
are shown in FIG. 10(a). In comparison with Example 12, the output
power of the SE type ECF motor was higher than that of the RE type
ECF motor, but the RE type ECF motor was superior to the SE type
ECF motor in the change of the rotational speed for the load
torque.
Example 14
[0270] In the RE type ECF motor shown in FIG. 3, dibutyl
decanedioate was used as the electro-sensitive movable fluid, the
diameter of the fluid container was made to be 30 mm, and the
diameter of the cylindrical rotor was varied to 10 mm, 16 mm or 20
mm. In each case, the rotational speed and the output torque were
measured. The results are shown in FIG. 10(b). When the diameter of
the cylindrical rotor 46 was 20 mm, a high output torque was
obtained.
Example 15
[0271] In the RE type ECF motor shown in FIG. 3, dibutyl
decanedioate was used as the electro-sensitive movable fluid, and
the diameter of the fluid container and the diameter of the vane
rotor were varied to 20 mm and 10 mm, respectively, 30 mm and 16 mm
respectively, or 40 mm and 20 mm, respectively. In each case, the
rotational speed and the output torque were measured. The results
are shown in FIG. 10(c). It was found that with a smaller diameter
of the fluid container 41, the output torque at the same rotational
speed was increased and the change of the rotational speed for the
load torque was increased.
Example 16
[0272] A SE type ECF motor with the same structure as shown in FIG.
2 and larger than the motor of Example 1 was used. This SE type ECF
motor is provided with a bottomed cylindrical container having an
inner diameter of 26 mm as the fluid container and a vane rotor
having 6 vanes each being large in proportion to the container's
size. The fluid container was provided with 8 electrodes (3a to
3h), wherein 3a and 3e were set to be positive electrodes and the
remainders 3b, 3c, 3d, 3f, 3g and 3h were grounded so as to be
negative electrodes.
[0273] The fluid container was filled with about 17 ml of
2,2,4-trimethyl-1,3-pentanediol diisobutyrate represented by the
following formula (trade name: Kyowanol D, available from Kyowa
Hakko Kogyo Co., Ltd.), and a direct-current-voltage of 5 kV or 6
kV was applied. 35
[0274] When the direct-current-voltage was applied, the rotor 18
having 6 vanes began to rotate and continued to rotate during the
application of voltage. When the voltage was varied to 6 kV from 5
kV, the rotational speed was increased. The results are set forth
in Table 6. The measurement of the current in Examples 15 to 29 was
carried out by means of a commercially available ammeter. The lower
limit of the measurement by this ammeter is 0.05 mA. By the
expression "<0.05 unmeasurable" in the following tables is meant
that the current was lower than the lower limit of the measurement
by the ammeter.
5 TABLE 6 Voltage (DC-kV) 5.0 6.0 Rotational speed 72 100 (rpm)
Current (mA) <0.05 unmeasurable <0.05 unmeasurable
Example 17
[0275] The procedure of Example 16 was repeated except that
glycerol triacetate represented by the following formula (alias
"triacetin", available from Daihachi Chemical Industry Co., Ltd.)
was used in the same amount in place of
2,2,4-trimethyl-1,3-pentanediol diisobutyrate (trade name: Kyowanol
D, available from Kyowa Hakko Kogyo Co., Ltd.) and the applied
voltage was varied to 6.0 kV. 36
[0276] When a direct-current-voltage of 6 kV was applied, the rotor
18 began to rotate at 60 rpm. The pointer of the ammeter was
confirmed to slightly move at the moment the voltage was applied.
However, the current was lower than the lower limit (0.05 mA) of
the measurement by the ammeter and the accurate value was unable to
be measured.
Example 18
[0277] The procedure of Example 16 was repeated except that a
container provided with 16 electrodes at the same intervals on the
inner surfce was used in place of the container provided with 8
electrodes at the same intervals on the inner surifce.
[0278] The fluid filled in the container was
2,2,4-trimethyl-1,3-pentanedi- ol diisobutyrate which was the same
fluid as used in Example 16.
[0279] Of the electrodes, the first, fifth, ninth and thirteenth
electrodes clockwise numbered were set to be positive ones, and the
second, sixth, tenth and fourteenth electrodes were grounded so as
to set to be negative ones. Then, a direct-current-voltage of 6 kV
was applied. The third, fourth, seventh, eighth, eleventh, twelfth,
fifteenth and sixteenth electrodes were dummy electrodes. The
interval between the positive and negative electrodes in the case
of using 16 electrodes was 1/2 of the interval in the case of using
8 electrodes.
[0280] When a direct-current-voltage of 6 kV was applied, the rotor
18 began to rotate and continued to rotate at 158 rpm during the
application of voltage. The pointer of the ammeter was confirmed to
slightly move at the moment the voltage was applied. However, the
current was lower than the lower limit (0.05 mA) of the measurement
by the ammeter and the accurate value was unable to be measured,
similarly to the case of using 8 electrodes.
[0281] As a result, it was confirmed that the rotational speed of
the rotor was increased with a smaller interval between the
positive and negative electrodes.
[0282] Further, when the direct-current-voltage was applied in the
manner described in Examples 16 to 18, rise of the
electro-sensitive movable fluid along either of the positive and
negative electrodes was observed.
Example 19
[0283] The procedure of Example 16 was repeated except that 15 ml
of 2-methoxy-l-methylethyl acetate represented by the following
formula (trade name: Arcosolve PMA, available from Kyowa Hakko
Kogyo Co., Ltd.) was used as the electro-sensitive movable fluid.
That is, in this example, a vane rotor provided with 6 vanes at the
same intervals was used, 15 ml of 2-methoxy-1-methylethyl acetate
represented by the following formula was used as the
electro-sensitive movable fluid, the electrodes 3a and 3e were set
to be positive electrodes and the remainders were grounded so as to
be negative ones, and a direct-current-voltage was applied. 37
[0284] As a result, the vane rotor began to rotate immediately
after the application of voltage and continued to rotate during the
application of voltage. The relation between the applied voltage
and the rotational speed is set forth in Table 7. As is clear from
Table 7, the current during the application of voltage was lower
than the lower limit (0.05 mA) of the measurement by the
ammeter.
6 TABLE 7 Voltage (DC-kV) 5.0 6.0 Rotational speed 109 152 (rpm)
Current (mA) <0.05 unmeasurable <0.05 unmeasurable
Example 20
[0285] The vane rotor was rotated in the same manner as in Example
19, except that a mixture of the compounds represented by the
following formulas was used as the electro-sensitive movable fluid
in place of 2-methoxy-1-methylethyl acetate (trade name: Arcosolve
PMA, available from Kyowa Hakko Kogyo Co., Ltd.).
7 38 (Mixing ratio 90% by weight: 10% by weight)
[0286] That is, this electro-sensitive movable fluid was a mixture
of isomers of propylene glycol monoethyl ether acetate (trade name:
BP Ethoxypropyl Acetate, available from Kyowa Hakko Kogyo Co.,
Ltd.). The relation between the applied voltage and the rotational
speed is set forth in Table 8. As is clear from Table 8, the
current during the application of voltage was lower than the lower
limit (0.05 mA) of the measurement by the ammeter.
8 TABLE 8 Voltage (DC-kV) 5.0 6.0 Rotational speed 61 106 (rpm)
Current (mA) <0.05 unmeasurable <0.05 unmeasurable
Example 21
[0287] The electro-sensitive movable fluid used in Example 20 was a
mixture of two compounds, and the fluid showed good electric
sensitivity. In this example, one of the compounds,
1-ethoxy-2-acetoxypropane represented by the following formula, was
used as the electro-sensitive movable fluid. 39
[0288] That is, the procedure of Example 19 was repeated except
that 1-ethoxy-2-acetoxypropane (available from Wako Junyaku K. K.)
which is one of the compounds of the mixture used in Example 20 was
used singly without mixing it with any other components or adding
any other components. The relation between the applied voltage and
the rotational speed is set forth in Table 9. As is clear from
Table 9, the current during the application of voltage was lower
than the lower limit (0.05 mA) of the measurement by the
ammeter.
9 TABLE 9 Voltage (DC-kV) 5.0 6.0 Rotational speed 82 180 (rpm)
Current (mA) <0.05 unmeasurable <0.05 unmeasurable
Example 22
[0289] A direct-current-voltage of 5.0 kV was applied in the same
manner as in Example 19, except that dibutyl diglycol adipate
represented by the following formula (trade name: BXA, available
from Daihachi Chemical Industry Co., Ltd.) was used in place of
2-methoxy-1-methylethyl acetate (trade name: Arcosolve PMA,
available from Kyowa Hakko Kogyo Co., Ltd.). 40
[0290] As a result, the rotor began to rotate immediately after the
application of voltage and continued to rotate during the
application of voltage. However, the rotational speed was not
constant and one rotation took 2.3 to 6.5 seconds.
[0291] In addition, there was also observed sudden stop of the
rotor or vigorous right-left vibration of the rotor followed by the
normal rotary motion. The cause of such behaviors has not been
clarified yet, but those behaviors seem to be phenomena
specifically observed in some of the compounds represented by the
formula [II]. In each case, the current during the application of
voltage was lower than the lower limit (0.05 mA) of the measurement
by the ammeter.
Example 23
[0292] The applied voltage and the rotational speed were measured
in the same manner as in Example 19 by means of the same SE type
ECF motor as in Example 19, except that 3-methoxy-3-methylbutyl
acetate represented by the following formula (trade name: Solfit
Acetate, available from Kuraray Co., Ltd.) was used as the
electro-sensitive movable fluid. 41
[0293] The results are set forth in Table 10.
10 TABLE 10 Voltage (DC-kV) 5.0 6.0 Rotational speed 75 110 (rpm)
Current (mA) <0.05 unmeasurable <0.05 unmeasurable
Example 24
[0294] The applied voltage and the rotational speed were measured
in the same manner as in Example 19 by means of the same SE type
ECF motor as in Example 19, except that diethylene glycol butyl
ether acetate represented by the following formula (trade name:
Butyl Carbitol Acetate, available from Union Carbide) was used as
the electro-sensitive movable fluid. 42
[0295] The results are set forth in Table 11.
11 TABLE 11 Voltage (DC-kV) 5.0 6.0 Rotational speed 82 135 (rpm)
Current (mA) <0.05 unmeasurable <0.05 unmeasurable
Example 25
[0296] The compound represented by the following formula [D] or
[D-1], each of which is very similar to the compound of the formula
[III], is also employable as the electro-sensitive movable fluid of
the invention. 43
[0297] The compounds represented by the above formulas are
compounds wherein X.sup.4 and Y.sup.4 are linked by an ester
linkage. X.sup.4 and Y.sup.4 may be the same as or different from
each other. X.sup.4 and Y.sup.4 are each basically a monovalent
hydrocarbon group and may contain a hetero atom such as an oxygen
atom, a nitrogen atom or a sulfur atom. Further, X.sup.4 and
Y.sup.4 may have a functional group such as a double bond and may
be linear or branched. However, the compound represented by the
formula [D] contains no halogen atom (e.g., chlorine atom, fluorine
atom, bromine atom, iodine atom). By virtue of the absence of
halogen atom in the electro-sensitive movable fluid of the
invention, even when the electro-sensitive movable fluid is applied
to an apparatus made of a metal, the corrosion of the apparatus
does not take place, and the movable fluid is safe to the human
body or the environment even when it is decomposed. The presence of
a small amount of halogen atom had been thought to be essential to
the movable fluid in the past, but as a result of studies by the
present inventors, it has been found that the structure was more
dominative than the presence of halogen atom in the
electricity-sensitive working fluids. Accordingly, the presence of
a halogen atom is not essential to the electro-sensitive movable
fluid of the invention. On the contrary, in consideration of
corrosion of the apparatus or bad influences on the human body and
the environment, it is preferable that no halogen atom is contained
in the electro-sensitive movable fluid of the invention.
[0298] Of the compounds represented by the formula [D], those
having an epoxy group present in the following formula or 3,
7-dimethyl-1,6-octadien-3-yl acetate represented by the following
formula (trade name: Linalyl Acetate, available from Kurarey Co.,
Ltd.) are preferable from the viewpoint of the action of converting
electric energy to rotational energy.
Example Using Compound Having Epoxy Group
[0299] 44
[0300] The SE type ECF motor having a vane motor with 6 vanes,
which was used in Example 19, was filled with about 15 ml of
9,10-epoxy butyl stearate (trade name: Sansocizer E4030, available
from New Japan Chemical Co., Ltd.) to set the SE type ECF
motor.
[0301] The electrodes 3a and 3e were set to be positive electrodes
and the remainders were grounded so as to be negative ones. Then, a
direct-current-voltage of 6.0 kV was applied.
[0302] As a result, the SE type ECF motor began to rotate
immediately after the application of voltage and continued to
rotate at 45 rpm during the application of voltage. The current
during the application of voltage was lower than the lower limit
(0.05 mA) of the measurement by the ammeter.
Example Using 3,7-dimethyl-1,6-octadien-3-yl acetate
[0303] 45
[0304] A direct-current-voltage of 6 kV was applied in the same
manner as in Example 19, except that the SE type ECF motor having a
vane motor with 6 vanes, which was used in Example 19, was filled
with 3,7-dimethyl-1,6-octadien-3-yl acetate represented by the
above formula (trade name: Linalyl Acetate, available from Kurarey
Co., Ltd.).
[0305] As a result, the SE type ECF motor began to rotate
immediately after the application of voltage and continued to
rotate at 126 rpm during the application of voltage. The current
during the application of voltage was lower than the lower limit
(0.05 mA) of the measurement by the ammeter.
Example 26
[0306] The electrode 53 of the RE type ECF motor shown in FIG. 3
was set to be a positive electrode and the electrode 52 thereof was
set to be a negative electrode. Supply of the electric power to the
electrodes arranged on the cylindrical rotor was carried out
through the rotational contact point of mercury. Arrangement of the
electrodes and polarities thereof are shown in FIG. 3. The bearing
section at the center of the bottom of the fluid container was
provided with ball bearings to reduce friction of the shaft.
[0307] As shown in FIG. 3, a cylindrical rotor having a diameter of
20 mm and a height of 50 mm was arranged in the fluid container,
and the container was filled with the following electro-sensitive
movable fluids individually to completely immerse the whole rotor.
The length of the electrode provided on the rotor was 50 mm, and
the interval angle .theta. between the electrodes was
22.5.degree..
[0308] When a direct-current-voltage of 6.0 kV was applied, the
rotor began to rotate clockwise, and the rotary motion of the rotor
was continued during the application of voltage. When the polarity
of the applied voltage was reversed, the rotor began to rotate
counterclockwise, and the counterclockwise rotation was
continued.
[0309] The rotational speed (rad/s) for each movable fluid was
measured. The results are set forth in Table 12.
[0310] The types I to V of the electro-sensitive movable fluids
shown in Table 12 have structures represented by the following
formulas. 46
[0311] In the above formula, X.sup.1 is a divalent group of 1 to 14
carbon atoms which may have either a branched chain, an ether
linkage or an ester linkage, and Y.sup.1 and Z.sup.1 are each
independently an alkyl group or 1 to 5 carbon atoms which may have
a branch. 47
[0312] In the above formula, X.sup.2 is a divalent alkyl group of 2
to 9 carbon atoms which may have a branch, Y.sup.2 is a divalent
alkyl group of 1 to 6 carbon atoms, Z.sup.2 is an alkyl group of 1
to 6 carbon atoms which may have a branch, n is an integer of 1 to
4, m is an integer of 1 or 2. When m is 1, A is a hydrogen atom.
When m is 2, the compound of this formula is a symmetric dimer
having A as a bonding hand in which groups each represented by
(Z.sup.2--O--(X.sup.2--O).sub.n--CO--Y.sup.2)-- - are directly
bonded to each other. 48
[0313] In the above formula, X.sup.3 is a monovalent group having
carbon atoms (a), oxygen atoms (b) and hydrogen atoms (2a+1 -2b)
wherein a is an integer of 1 to 25, b is 0, 1, 2 or 3, and
2a+1>2b, and Y.sup.3 is a hydrocarbon group of 1 to 14 carbon
atoms which may have a branched chain and/or a carbon-to-carbon
double bond. 49
[0314] In the above formulas of the types IV and V, R.sup.1 and
R.sup.2 are each independently a hydrocarbon group which may
contain an atom other than carbon and hydrogen, R.sup.1 and R.sup.2
may be the same as or different from each other, and X is a
divalent group represented by the following formula [VI] or [VII]:
50
[0315] wherein R.sup.3 and R.sup.4 are each a hydrocarbon group
which may have a branch and to which an atom other than carbon and
hydrogen may be bonded, R.sup.3 and R.sup.4 may be the same as or
different from each other, q and r are each independently 0 or an
integer of 1 or more, when q or r is 0, R.sup.3 and R.sup.4 are
each independently a single bond, p is 0 or an integer of 1, 2 or
3, a cyclic structure regulated by p may have a substituent, and
the cyclic structure may be partly or wholly hydrogenated;
--C.sub.nH.sub.(2n-2m)-- [VII]
[0316] wherein n is an integer of 2 or more, and m is the number of
double bonds contained in this group. 51
[0317] In the above formula, Z.sup.4 is an alkyl group of 1 to 5
carbon atoms which contains any one of 52
[0318] a single bond and --O--CH.sub.2-- and 53
[0319] and which may have a branch, X.sup.4 is a hydrocarbon group
of 1 to 17 carbon atoms which may have a branch, Y.sup.4 is a
hydrocarbon group of 1 to 20 carbon atoms which may have a branch,
and X.sup.4 and Y.sup.4 may have a hetero atom and/or an
unsaturated bond.
12TABLE 12 Rotational speed Type Electricity-sensitive working
medium (rad/s) I 2,2,4-Trimethyl-1,3-pentanediol diisobutyrate 16.5
54 I Glycerol triacetate 9.6 55 II
2-Methoxy-1-methoxy-1-methylethyl acetate 25.0 56 II Propylene
glycol monoethyl ether acetate (mixture) 17.4 57 II
3-Methoxy-3-methylbutyl acetate 18.0 58 II Diethylene glycol butyl
ether acetate 22.1
C.sub.4H.sub.9--O--(CH.sub.2--CH.sub.2O).sub.2--CO--- CH.sub.3 III
9,10-Epoxy butyl stearate 7.3 59 III 3,7-Dimethyl-1,6-octadien-3-yl
acetate 29.0 60 IV Dibutyl itaconate 20.3 61 IV Dibutyl
decanedioate 14.0 C.sub.4H.sub.9--O--CO--(CH.-
sub.2).sub.8--CO--O--C.sub.4H.sub.9 IV Butyl benzyl phthalate 5.8
62 V Methyl acetyl ricinoleate 6.9 63
[0320] In the use of each of the electro-sensitive movable fluids,
the value of the direct current in the measurement of the
rotational speed was lower than the lower limit (0.05 mA) of the
measurement by the ammeter, and the accurate value was unable to be
measured.
Example 27
[0321] The output torque (basic characteristics of the RE type ECF
motor of the invention) was measured by the use of a measuring
device shown in FIG. 11. In FIG. 11, the number 30 represents a RE
type ECF motor.
[0322] The RE type ECF motor 30 used for the measurement had a
structure shown in FIG. 3. The inner diameter of the fluid
container was 30 mm. As for the cylindrical rotor, three kinds of
rotors having a height of 50 mm and having different diameters,
i.e., rotor A 10 mm in diameter, rotor B 16 mm in diameter and
rotor C 20 mm in diameter, were used. The interval angle between
the electrodes was 22.5.degree.. The rotor C was the same rotor as
used in Example 26.
[0323] As the electro-sensitive movable fluid, dibutyl decanedioate
which was the same fluid as used in Example 26 was used. The fluid
container was filled with the movable fluid to completely immerse
the whole cylindrical rotor.
[0324] Then, a direct-current-voltage of 6.0 kV was applied. As a
result, each of the rotors A to C began to rotate immediately after
the application of voltage. The rotational speed, the output torque
and the current were measured with respect to each rotor.
[0325] The results are set forth in Tables 13 to 15,
respectively.
13TABLE 13 Inner diameter of fluid container: 30 mm Rotor A
(diameter: 10 mm) Rotational speed Output torque Current (rad/s)
(.mu.N .multidot. m) (.mu.A) 30.6 0.0 12.0 20.9 5.5 12.0 14.0 12.3
12.0 11.3 14.7 12.0
[0326]
14TABLE 14 Inner diameter of fluid container: 30 mm Rotor B
(diameter: 16 mm) Rotational speed Output torque Current (rad/s)
(.mu.N .multidot. m) (.mu.A) 17.9 0.0 7.0 16.5 2.6 7.0 12.3 8.8 7.0
9.1 17.2 7.0
[0327]
15TABLE 15 Inner diameter of fluid container: 30 mm Rotor C
(diameter: 20 mm) Rotational speed Output torque Current (rad/s)
(.mu.N .multidot. m) (.mu.A) 12.6 0.0 6.0 11.6 3.2 6.0 8.7 13.3 6.0
8.1 20.8 6.0
[0328] As is clear from the results, with a larger diameter of the
cylindrical rotor, a higher output torque was obtained. The reason
is assumably that because of the narrow gap between the fluid
container (housing) and the cylindrical rotor, the jet flow of the
fluid produced between the electrodes is efficiently transformed to
the rotary motion by means of the viscous force of the fluid.
Example 28
[0329] Fluid containers (housings) having inner diameters of 20 mm
and 40 mm were prepared. In the fluid container having an inner
diameter of 20 mm, the rotor A having a diameter of 10 mm which was
used in Example 27 was set, while in the fluid container having an
inner diameter of 40 mm, the rotor C having an inner diameter of 20
mm which was used in Example 27 was set. Then, the rotational
speed, the output torque and the current were measured in the same
manner as in Example 27.
[0330] The results are set forth in Table 16 and 17,
respectively.
16TABLE 16 Inner diameter of fluid container: 20 mm Rotor A
(diameter: 10 mm) Rotational speed Output torque Current (rad/s)
(.mu.N .multidot. m) (.mu.A) 30.6 0.0 12.0 19.3 4.8 12.0 11.4 16.1
12.0 7.9 19.3 12.0
[0331]
17TABLE 17 Inner diameter of fluid container: 40 mm Rotor C
(diameter: 20 mm) Rotational speed Output torque Current (rad/s)
(.mu.N .multidot. m) (.mu.A) 14.0 0.0 6.0 10.1 9.9 6.0 9.2 10.5
6.0
[0332] As is clear from the result, the ratio of the housing
diameter to the rotor diameter in this example was 2.0, while the
ratio of the housing diameter to the rotor diameter in Table 15 of
Example 27 was 1.9. It was confirmed from the results that with
decrease of the diameter of the housing, namely, with
miniaturization of the housing, the output torque at the same
rotational speed was increased and the change of the rotational
speed for the output torque was increased.
Example 29
[0333] The rotational speed, output torque and the current were
measured in the same manner as in Example 27, except that a fluid
container having an inner diameter of 24 mm was used and three
kinds of rotors having different interval angles of the electrodes,
i.e., rotor C-2 having an interval angle .theta. of 11.30.degree.,
rotor C-3 having an interval angle of 45.0.degree. and rotor C
having an interval angle of 22.5.degree., were used.
[0334] The results are set forth in Table 18 to 20,
respectively.
18TABLE 18 Inner diameter of fluid container: 24 mm Rotor C-2
(diameter: 20 mm, .theta.: 11.3.degree.) Rotational speed Output
torque Current (rad/s) (.mu.N .multidot. m) (.mu.A) 10.6 0.0 12.0
9.0 30.5 12.0 7.7 56.0 12.0 6.3 83.7 12.0
[0335]
19TABLE 19 Inner diameter of fluid container: 24 mm Rotor C
(diameter: 20 mm, .theta.: 22.5.degree.) Rotational speed Output
torque Current (rad/s) (.mu.N .multidot. m) (.mu.A) 12.6 0.0 6.0
12.0 9.4 6.0 10.5 35.5 6.0 8.6 58.4 6.0
[0336]
20TABLE 20 Inner diameter of fluid container: 24 mm Rotor C-3
(diameter: 20 mm, .theta.: 45.0.degree.) Rotational speed Output
torque Current (rad/s) (.mu.N .multidot. m) (.mu.A) 12.6 0.0 5.6
10.3 21.0 5.6 9.2 43.0 5.6 8.5 52.2 5.6
Example 30
[0337] The rotational speed was measured in the same manner as in
Example 26, except that a mixture of dibutyl decanedioate (97.5% by
weight) and petroleum benzine (2.5% by weight, available from
Nippon Oil Co., Ltd.) was used as the electro-sensitive movable
fluid. As a result, the rotational speed was 20.2 rad/s, and this
speed was biggar rather than one containing only dibutyl
decanedioate as a movable fluid described in Example 26 (14.0
rad/s). This means that the electric sensitivity of dibutyl
decanedioate was improved and provided bigger rotational speed by
adding petroleum benzine. The current was lower than the lower
limit (0.05 mA) of the measurement by the ammeter.
* * * * *