U.S. patent application number 11/755304 was filed with the patent office on 2007-12-06 for vortex pump.
This patent application is currently assigned to NIDEC Sankyo Corporation. Invention is credited to TAKESHI OZAWA.
Application Number | 20070280837 11/755304 |
Document ID | / |
Family ID | 38790425 |
Filed Date | 2007-12-06 |
United States Patent
Application |
20070280837 |
Kind Code |
A1 |
OZAWA; TAKESHI |
December 6, 2007 |
VORTEX PUMP
Abstract
A vortex pump comprises: an impeller that includes a plurality
of blades at an outer circumference and a rotor magnet placed at an
inner circumference; a shaft fixed at a center of the impeller; a
bearing component placed at an outer circumference of the shaft; a
motor stator placed at an inner circumference side of the rotor
magnet; and a case structural component having a suction port and a
discharge port that functions to house the impeller and furthermore
to divide the impeller and the motor stator. A motor stator side
surface of the case structural component is covered with an
adhesive material to cause the motor stator to adhere to the motor
stator side surface.
Inventors: |
OZAWA; TAKESHI; (Nagano,
JP) |
Correspondence
Address: |
REED SMITH, LLP;ATTN: PATENT RECORDS DEPARTMENT
599 LEXINGTON AVENUE, 29TH FLOOR
NEW YORK
NY
10022-7650
US
|
Assignee: |
NIDEC Sankyo Corporation
|
Family ID: |
38790425 |
Appl. No.: |
11/755304 |
Filed: |
May 30, 2007 |
Current U.S.
Class: |
417/354 |
Current CPC
Class: |
F04D 13/064 20130101;
F04D 29/628 20130101; F04D 13/0633 20130101; F04D 5/002
20130101 |
Class at
Publication: |
417/354 |
International
Class: |
F04B 17/00 20060101
F04B017/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 6, 2006 |
JP |
2006-156859 |
May 8, 2007 |
JP |
2007-123958 |
Claims
1. A vortex pump comprising: an impeller that includes a plurality
of blades at an outer circumference and a rotor magnet placed at an
inner circumference; a shaft fixed at a center of the impeller; a
bearing component placed at an outer circumference of the shaft; a
motor stator placed at an inner circumference side of the rotor
magnet; and a case structural component having a suction port and a
discharge port that functions to house the impeller and furthermore
to divide the impeller and the motor stator; wherein a motor stator
side surface of the case structural component is covered with an
adhesive material to cause the motor stator to adhere to the motor
stator side surface.
2. The vortex pump according to claim 1 wherein thickness of a wall
of the case structural component at a side, which divides the
impeller and the motor stator, is at least 0.2 mm and thinner than
1.5 mm.
3. The vortex pump according to claim 1 wherein the bearing
component is a ball bearing, and a circular protruded section
centered at the shaft is placed at an outer circumference section,
which is outside a position including an outer race of the ball
bearing and at a lower surface of a motor stator side of the
impeller.
4. The vortex pump according to claim 1 wherein a lid component
placed on the case structural component that houses the impeller is
welded onto the case structural component.
5. A vortex pump comprising: an impeller that includes a plurality
of blades at an outer circumference and a rotor magnet placed at an
inner circumference; a shaft fixed at a center of the impeller; a
bearing component placed at an outer circumference of the shaft; a
motor stator placed at an inner circumference side of the rotor
magnet; and a case structural component having a suction port and a
discharge port that works to house the impeller and furthermore to
divide the impeller and the motor stator; wherein the motor stator
is adhered and fixed with an adhesive material onto a surface of
the case structural component that faces the motor stator.
6. The vortex pump according to claim 5 wherein the motor stator is
equipped with a protruded pole part in which a wire-wound coil is
formed, and at least all the wire-wound coil is adhered and fixed
with an adhesive material onto a surface of the case structural
component that faces the motor stator.
7. The vortex pump according to claim 6 wherein all the wire-wound
coil and the protruded pole part are adhered and fixed with an
adhesive material onto a surface of the case structural component
that faces the motor stator.
8. The vortex pump according to claim 6 wherein thickness of a wall
of the case structural component at a side, which divides the
impeller and the motor stator, is at least 0.2 mm and thinner than
1.5 mm.
9. The vortex pump according to claim 8 wherein the motor stator is
equipped with a protruded pole part in which a wire-wound coil is
formed, and all the wire-wound coil and the protruded pole part are
embedded with a resin material so as to construct the integral-type
case structural component.
10. The vortex pump according to claim 6 wherein the bearing
component is a ball bearing, and a circular protruded section
centered at the shaft is placed at an outer circumference section,
which is outside a position including an outer race of the ball
bearing and at a lower surface of a motor stator side of the
impeller.
11. A vortex pump comprising: an impeller that includes a plurality
of blades at an outer circumference and a rotor magnet placed at an
inner circumference; a shaft fixed at a center of the impeller; a
bearing component placed at an outer circumference of the shaft; a
motor stator placed under the impeller and at an inner
circumference side of the rotor magnet; and an integral-type case
structural component having a suction port and a discharge port,
which functions to house the impeller, and furthermore in which the
motor stator is embedded.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority of Japanese Application No.
2006-156859, filed Jun. 6, 2006 and Japanese Application No.
2007-123958, filed May 8, 2007, the complete disclosures of which
are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] a) Field of the Invention
[0003] The present invention relates to a vortex pump in which a
fluid sucked through a suction port by revolution of an impeller
passes through a fluid path and gets discharged from a discharge
port; and furthermore in detail, the invention relates to such a
vortex pump provided with a structure that enables the vortex pump
to become further low-profile designed.
[0004] b) Description of the Related Art
[0005] In recent years, as a method of efficiently cooling down
CPUs and so on of notebook-sized personal computers and so forth, a
system that circulates a refrigerant in it by using a pump for
refrigerant circulation has been under research. For a pump to be
used in such a system, it is required to have a long operating
life, and also to be provided with low-profile design in the same
way as a trend of low-profile design of notebook-sized personal
computers. Furthermore in recent years, a fuel battery to be used
in notebook-sized personal computers and so on has also been under
research. Also in a fuel supplying unit that supplies such a fuel
battery with fuel (oxygen, air, water, and so forth), a small-sized
pump is used. For a pump to be used for a fuel battery, it is
especially desired to use a model with less power consumption for
the purpose of reducing the power consumption of the pump itself as
much as possible.
[0006] As one of small-sized pumps of conventional models, a vortex
pump described in Japanese Unexamined Patent Publication (Kokai)
No. 2003-161284, for example, includes: an impeller in which a
large number of blades are formed at an outer circumference and a
rotor magnet is placed at an inner circumference; a shaft on which
the impeller revolves; a motor stator that is placed at an inner
circumference side of the rotor magnet; and a pump casing that
divides the impeller and the motor stator air-tightly and has a
suction port and a discharge port. The vortex pump is provided with
a motor structure including a structure of an outer rotor. In the
vortex pump, the impeller and the motor stator are combined
together and air-tightly divided so as to materialize compact
design and low-profile design.
SUMMARY AND OBJECT OF THE INVENTION
a) Problem to be Solved
[0007] Considering a trend of compact design and weight saving of
portable devices represented by notebook-sized personal computers
and so forth in recent years, further compact design and
low-profile design are still requested even in the vortex pump
described in the reference above and so on. Under such
circumstances; in the course of an examination of thinning a
thickness of each structural member down to its limit in order to
thinly shape a vortex pump still further, the inventor of the
present invention has noticed that, when a wall thickness of a pump
casing air-tightly dividing an impeller and a motor stator is made
thinner, micro vibration during revolution of the impeller causes
sympathetic vibration with the thin-walled pump casing so as to
generate a large noise. Generation of such a noise is a significant
problem especially when a portable device is concerned, and
countermeasures for the problem are critical. However, if the wall
thickness of the pump casing is made thicker for the purpose of
solving the problem of noise generation, there arises a problem
that low-shaping an entire profile of the vortex pump can no longer
be achieved.
b) Primary Object
[0008] The present invention aims at solving the problem identified
above, and it is a primary object of the present invention to
provide a vortex pump equipped with a structure that enables the
vortex pump to further become low-shaped.
c) Summary of the Invention
[0009] To solve the problem identified above, a vortex pump of the
present invention includes: an impeller that has a plurality of
blades at an outer circumference and a rotor magnet placed at an
inner circumference; a shaft fixed at a center of the impeller; a
bearing component placed at an outer circumference of the shaft; a
motor stator placed at an inner circumference side of the rotor
magnet; and a case structural component having a suction port and a
discharge port that works to house the impeller and furthermore to
divide the impeller and the motor stator; wherein a motor stator
side surface of the case structural component is covered with an
adhesive material to cause the motor stator to adhere to the motor
stator side surface. For another case, it is also possible to have
the motor stator adhered and fixed with an adhesive material onto a
surface of the case structural component that faces the motor
stator. In this case; it is possible that the motor stator is
equipped with a protruded pole part in which a wire-wound coil is
formed, and at least all the wire-wound coil is adhered and fixed
with an adhesive material onto a surface of the case structural
component that faces the motor stator. Still further, it is also
possible to have all the wire-wound coil and the protruded pole
part adhered and fixed with an adhesive material onto a surface of
the case structural component that faces the motor stator.
[0010] According to the present invention; the motor stator side
surface of the case structural component is covered with the
adhesive material, or the motor stator is adhered and fixed onto
the surface of the case structural component at the side of the
motor stator. Therefore, even if thickness of a section of the case
structural component that divides the impeller and the motor stator
is thin, sympathetic vibration of the case structural component can
be restrained. As a result, compact design and low-profile design
of the vortex pump can be achieved. Therefore, even if a wall in a
thrust direction of the case structural component that constructs
the surface section (hereinafter called a thrust-direction wall) is
thin enough so as to be at least 0.2 mm and thinner than 1.5 mm,
noise generation because of sympathetic vibration of the
thin-walled thrust-direction wall caused with micro vibration
during revolution of the impeller can be restrained and then
low-profile design can be realized as an entire profile of the
pump. As a result, a low-shaped vortex pump can be provided while
securing stable revolution of the pump for a long time.
[0011] A vortex pump of the present invention is especially
effective when thickness of a wall of the case structural component
at a side, which divides the impeller and the motor stator, (the
thrust-direction wall) is at least 0.2 mm and thinner than 1.5
mm.
[0012] In a vortex pump of the present invention, it is preferable
that the bearing component is a ball bearing, and a circular
protruded section centered at the shaft is placed at an outer
circumference section, which is outside a position including an
outer race of the ball bearing and at a lower surface of a motor
stator side of the impeller.
[0013] According to the invention, since a ball bearing is used as
the bearing component, and the ball bearing is effective for
preventing any play from arising. Furthermore, since a circular
protruded section centered at the shaft is placed, it is possible
for a space surrounded by the protruded section and the shaft to
retain a lubricant material for the ball bearing, such as grease
and so on, without evaporation or scattering away. As a result, a
low-shaped vortex pump can be provided while securing stable
revolution of the pump for a long time.
[0014] In a vortex pump of the present invention, it is preferable
that a lid component placed on the case structural component that
houses the impeller is welded onto the case structural
component.
[0015] According to the invention, a mounting structure for
placement of the lid component is not a conventional
screw-fastening structure using an O-ring, which is disadvantageous
to low-profile design, so that an entire profile of the vortex pump
can be low-profiled.
[0016] To solve the above-referenced problem, another vortex pump
relating to the present invention includes: an impeller that has a
plurality of blades at an outer circumference and a rotor magnet
placed at an inner circumference; a shaft fixed at a center of the
impeller; a bearing component placed at an outer circumference of
the shaft; a motor stator placed under the impeller and at an inner
circumference side of the rotor magnet; and an integral-type case
structural component having a suction port and a discharge port
which works to house the impeller, and furthermore in which the
motor stator is embedded. In this case; it is possible that the
motor stator is equipped with a protruded pole part in which a
wire-wound coil is formed, and all the wire-wound coil and the
protruded pole part are embedded with a resin material so as to
construct the integral-type case structural component.
[0017] According to the invention; even if the thickness of a wall
at a side that divides the impeller and the motor stator is thin,
sympathetic vibration of the wall can be restrained so that compact
design and low-profile design of the vortex pump can be
materialized.
[0018] In a vortex pump according to the present invention, even if
the thickness of the thrust-direction wall that constructs a
surface of the case structural component at the motor stator side
is thin, noise generation because of sympathetic vibration of the
thin-walled thrust-direction wall caused with micro vibration
during revolution of the impeller can be restrained and then
low-profile design can be realized as an entire profile of the
pump. Therefore, a low-shaped vortex pump can be provided while
securing stable revolution of the pump for a long time. As a
result, the pump can be used preferably as a low-shaped pump with a
long operation life for cooling down a CPU of a portable device,
such as a notebook-sized personal computer and so on, as well as
for a fuel battery.
[0019] Preferred embodiments of the present invention are described
below with reference to the accompanying drawings. Further,
needless to say, a vortex pump of the present invention is not
limited to the example of the preferred embodiment described below
as far as the vortex pump has technical characteristics of the
present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In the drawings:
[0021] FIG. 1 is an exploded perspective view showing an example of
a vortex pump relating to the present invention;
[0022] FIG. 2 is an A-A cross-sectional drawing of the vortex pump
shown by FIG. 1;
[0023] FIG. 3 includes perspective views of a case structural
component, which is a constitutional element of the present
invention, when it is viewed from a side of a motor stator;
[0024] FIG. 4 is an explanatory drawing to show an example of
adhesive joining configuration of an adhesive material that covers
a surface at a side of the motor stator of the case structural
component;
[0025] FIG. 5 is an explanatory drawing to show another example of
adhesive joining configuration of an adhesive material that covers
a surface at a side of the motor stator of the case structural
component;
[0026] FIG. 6 is an explanatory drawing to show an example of a
configuration including an integral-type case structural component
in which the motor stator is integrated and embedded; and
[0027] FIG. 7 is an explanatory drawing to describe a preload given
onto the bearing component constructed by using the couple of ball
bearings that are stacked up.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] FIG. 1 is an exploded perspective view showing an example of
a vortex pump relating to the present invention, and meanwhile FIG.
2 is an A-A cross-sectional drawing of the vortex pump shown by
FIG. 1 when it is in assembled condition. FIG. 3 includes
perspective views of a case structural component, which is a
constitutional element of the present invention, when it is viewed
from a side of a motor stator; and meanwhile, FIG. 4 and FIG. 5 are
explanatory drawings showing condition of adhesive joining
configuration of an adhesive material that covers a surface at a
side of the motor stator of the case structural component.
[0029] As shown in FIG. 1 and FIG. 2, a vortex pump 1 of the
present invention is a pump in which a fluid (gas or liquid) is
introduced from a suction port 61 and discharged from a discharge
port 62; and the pump is equipped with; an impeller 20 that
includes a plurality of blades 22 at an outer circumference and a
rotor magnet 40 placed at an inner circumference; a shaft 41 fixed
at a center of the impeller 20; a bearing component 50 (supplied as
a couple of ball bearings 50a and 50b in FIG. 1) placed at an outer
circumference of the shaft 41; a motor stator 70 placed under the
impeller 20 and at an inner circumference side of the rotor magnet
40; a case structural component 60 having the suction port 61 and
the discharge port 62 that works to house the impeller 20 and
furthermore to divide the impeller 20 and the motor stator 70; and
a lid component 10 placed on the case structural component 60 that
houses the impeller 20. A feature of the present invention is that
a motor stator side surface 65 of the case structural component 60
is glued, or in other words, covered with an adhesive material 69
that cause the motor stator 70 to adhere to the motor stator side
surface 65. Incidentally, a member with a reference numeral 80 in
FIG. 1 and FIG. 2 is a substrate positioned under the motor stator
70.
[0030] In the present application; the terms of "on", "under",
"inner", and "outer" as well as "above", "bottom surface", "inner
circumference", and "outer circumference" and so on each represent
"a higher position", "a lower position", "an inner position", and
"an outer position" under condition where the drawings including
FIG. 1, FIG. 2 and so on are each viewed as a plane view while the
lid component 10 is located at a higher position in comparison with
the case structural components (the reference numeral 60, and
another reference numeral 75). Therefore, the description "under"
in the "under the impeller 20" described above represents "a lower
position", i.e., "a position closer to the substrate 80" in FIG. 2
under condition where the drawing is viewed in the same manner as
defined above. Meanwhile, the description "on" in the "on the case
structural component 60 that houses the impeller 20" described
above represents "a higher position", i.e., "a position closer to
the lid component 10" in FIG. 2 under condition where the drawing
is viewed in the same manner as defined above. Furthermore, the
description "a bottom surface" in a description "a bottom surface
at a motor stator side of the impeller 20" represents "a bottom
surface" under condition where the drawing is viewed in the same
manner as defined above. Still further, the description "an inner
circumference side" in the "at an inner circumference side of the
rotor magnet 40" described above represents "an inner circumference
side", i.e., "a position closer to the shaft" under condition where
the drawing is viewed in the same manner as defined above.
Meanwhile, in the same manner; a description "an outer
circumference side" contrarily represents "a position more distant
from the shaft".
[0031] The impeller 20 is a disk-shaped body of revolution equipped
with a plurality of blades 22 at an outer circumference, and as
FIG. 1 and FIG. 2 show, the impeller 20 includes a ring-shaped
blade component 21, a disk-shaped rotor yoke 30 whose outer
circumference is equipped with the blade component 21, and a
ring-shaped rotor magnet 40 placed at an inner surface side of an
outer circumference wall 32 of the rotor yoke 30. The impeller 20
is fixed to the shaft 41, which is supported by the bearing
component 50 mounted on the case structural component 60. Thus the
impeller 20 is housed within a space that the lid component 10 and
the case structural component 60 comprise, and a vortex flow of a
fluid can be generated by revolution of the impeller.
[0032] The blade component 21 is, a ring-shaped component made of
heat resistance plastic (PPS: poly-phenylene-sulfide), for example,
and so on; and the blade component is fixed on an outer
circumference surface of the outer circumference wall 32 of the
disk-shaped rotor yoke 30 with an adhesive material and so on. The
blades 22 formed on the blade component 21 are in a form of a
plurality of grooves 23 placed along a circumferential direction at
an outer circumference of the blade component 21. The grooves 23
are formed at both edge sections, where end surfaces (i.e., upper
and lower surfaces) of the blade component 21 intersect with an
outer circumference surface, and the grooves are formed by cutting
the edge sections of the blade component 21 into fan-shaped forms.
No particular restriction exists on the number of the blades 22,
and usually the blades are placed at an optional pitch according to
the size of the blade component 21.
[0033] The rotor yoke 30 is a disk-shaped component at which the
blade component 21 is mounted on an outer circumference surface of
the outer circumference wall 32; and it is preferable that the
rotor yoke is made of a magnetic material such as, for example, an
SK material (tool carbon steel) on which anti-corrosion surface
treatment is done. The outer circumference surface of the rotor
yoke 30 is formed with a dimension that makes it possible to mount
the blade component 21. Furthermore, it is preferable that, as FIG.
1 and FIG. 2 show, a protrusion edge part 36 is formed, for
example, at a bottom edge of the outer circumference surface, for
the purpose of locating the blade component 21 in engagement at a
specified position.
[0034] The rotor magnet 40 is a ring-shaped component placed at an
inner surface side of the outer circumference wall 32 of the rotor
yoke 30 by using an adhesive material and so on. For the rotor
magnet, a permanent magnet such as, for example, a neodymium-bond
magnet and so on is used. The rotor magnet 40 is located at a
position which, being under the impeller 20, faces the motor stator
70 placed at an inner circumference side of the rotor magnet 40;
and in cooperation with the motor stator 70, the rotor magnet makes
the impeller 20 revolve in driving. Preferably used in the present
invention is an outer-rotor-type motor in which the rotor magnet 40
positioned at an outer circumference side revolves.
[0035] The impeller 20 constructed as described above is fixed to
the shaft 41, which is supported by the bearing component 50. No
particular restriction exists on a configuration of the bearing
component 50. For example, a ball-bearing-type component as shown
in FIG. 1 and FIG. 2 is preferably used; but a sleeve-type
component, which is not illustrated, can also be used instead.
[0036] In cooperation with the lid component 10, the case
structural component 60 makes up a space, in which the impeller 20
is housed. The case structural component 60 has the suction port 61
to suck a fluid, a fluid path 63 through which the fluid made into
a vortex flow by revolution of the impeller 20 flows, and the
discharge port 62 to discharge the fluid. Incidentally, no
particular restriction exists on a material for the case structural
component 60 and the lid component 10, however, it is preferable
that, from the viewpoint of reduction in size and weight, a light
metal such as an aluminum material or an aluminum alloy and so on,
or a heat resistance plastic material (PPS) is used.
[0037] The fluid path 63 constructed by the case structural
component 60 and the lid component 10 is formed with a wide width
so as to surround a fringe of the blades 22, and a cross-section of
the fluid path 63 is shaped into size with which an outer section
of the blades 22 is surrounded so as to have a wide clearance. In a
configuration example shown in FIG. 2, while having the blades 22
almost located at its center position, the fluid path 63 is formed
to be about oval-shaped. At both ends of the fluid path 63, the
suction port 61 and the discharge port 62 are formed. In the
present invention; when the impeller 20 is revolved, a fluid
existing in the grooves 23 that the blade component 21 includes is
pressed so as to flow into the fluid path 63 by centrifugal
movement, meanwhile a fluid existing in the fluid path 63 is
contrarily sucked to flow into the blade component 21, so that the
fluid is transferred from the suction port 61 to the discharge port
62 while forming a vortex flow. As a result, usually the fluid path
63 in a vicinity of the suction port 61 is under a negative
pressure condition, while the fluid path 63 in a vicinity of the
discharge port 62 is under a positive pressure condition
[0038] On the case structural component 60 that houses the impeller
20, the lid component 10 is mounted in order to shield a space
built up by the lid component 10 and the case structural component
60. For mounting the lid component 10 onto the case structural
component 60, various means can be applied. However, from the
viewpoint of compact design and low-profile design, as shown in
FIG. 1 & FIG. 2, it is preferable that the lid component 10 is
welded onto the case structural component 60. For use as a welding
method, preferably selected for example is a method; where the case
structural component 60 including a protrusion for welding 91
formed on an edge surface 92 that contacts the lid component 10 is
used, and the lid component 10 is mounted on the case structural
component 60, and then laser radiation (for example, YAG laser and
so on) from a position above the lid component 10 is carried out
along the protrusion for welding 91 in order to weld together the
lid component 10 and the case structural component 60. Furthermore,
for use as another welding method, ultrasonic welding can also be
applied. Though no particular restriction exists on size of the
protrusion for welding 91, a width from 0.5 mm to 2.5 mm and a
height from 0.05 mm to 0.15 mm as the size can be exemplified when
entirely compact and low-profile design is taken into
consideration.
[0039] Thus, when a mounting structure for placement of the lid
component 10 by welding is applied instead of any other structure
such as a conventional screw-fastening structure using an O-ring
that is disadvantageous to low-profile design, an entire profile of
the vortex pump can be low-profiled. However, if there is a spare
space in size, it is still possible to apply any conventional
method using an O-ring or a sheet-shaped sealing material (a
silicone sheet and so on), a press-fit method, an adhering method
that uses an adhesive agent, and so on.
[0040] Although FIG. 1 shows an example where a through-hole 90 is
formed for the purpose of mounting the vortex pump 1 of the present
invention onto another component (such as a substrate not
illustrated, and so on) by using a bolt and nut and so forth, no
restriction particularly exists on a method of fastening the vortex
pump 1.
[0041] The motor stator 70 is placed under the case structural
component 60 and at an inner circumference side of the rotor magnet
40. In a stator yoke 71 included in the motor stator 70; a wire
winding section for forming a wire-wound coil, i.e., a protruded
pole part 711, is placed at certain intervals, and then a
wire-wound coil 72 is formed in the wire winding section. In the
present application, an example where 9 wire winding sections are
uniformly laid out is exemplified, as FIG. 1 and FIG. 3 show. An
outer circumference surface of the protruded pole part 711 of the
motor stator 70 is placed at a position that faces the rotor magnet
40. Then, in order to make it possible to restrain the impeller 20
from vibrating, a center level in a thickness direction of the
rotor magnet 40 is located a bit higher than a center level in a
thickness direction of the stator yoke 71, namely, of the protruded
pole part 711. Incidentally, size of the stator yoke 71 corresponds
to what can be housed in a lower space of the case structural
component 60, as shown in FIG. 3. Furthermore, it is preferable
that a material of the stator yoke is a magnetic material, as the
foregoing material of the rotor yoke 30 of the impeller 20 is.
[0042] Described next is a characteristic structure of the present
invention, i.e., an adhering configuration of the adhesive material
69 to be glued onto the motor stator side surface of the case
structural component 60. A wall in a thrust direction (hereinafter
called a thrust-direction wall 66) of the case structural component
60 is designed to be, for example, about at least 0.2 mm and
thinner than 1.0 mm in thickness for the purpose of realization of
further-low-profile design of a vortex pump. When the thin
thrust-direction wall 66 is made to be even thinner, micro
vibration during revolution of the impeller 20 causes sympathetic
vibration with the thin-walled thrust-direction wall 66 so as to
generate a large noise that becomes a significant problem
especially in a case where the pump is used for a portable device
and so on. In the present invention, as shown in FIG. 2 to FIG. 5,
a construction is given in such a way that the motor stator side
surface 65 of the case structural component 60 adheres to and gets
fixed to the motor stator, or in other words, the motor stator side
surface is covered with the adhesive material 69 in order to solve
the problem described above.
[0043] That is to say, it is preferable in the present invention
that strength of the thin thrust-direction wall 66 be increased by
covering the motor stator side surface 65 of the case structural
component 60, without any void part, with the adhesive material 69
so that, despite micro vibration during revolution of the impeller
20, no sympathetic vibration with the thrust-direction wall 66 is
caused. The adhesive material 69 preferably covers the motor stator
side surface 65 (hereinafter called "the wall surface 65" in
short), without any void part. In this occasion, "to cover the
surface without any void part" means that: if the wire-wound coil
72 which is a structural component of the motor stator 70 does not
contact the wall surface 65, only the adhesive material covers the
wall surface 65 without any void part; meanwhile if a structural
component of the motor stator 70 (for example, the wire-wound coil
72) contacts the wall surface 65, the adhesive material covers any
other section, without any void part, except a section where the
wire-wound coil 72 and the wall surface 65 contact each other so
that the adhesive material 69 cannot enter there.
[0044] The adhesive material is to be used for the purpose of
fixing the motor stator 70 to the lower space of the case
structural component 60 by applying the adhesive material. For use
as the adhesive material, various kinds of adhesive materials, for
example epoxy-base materials, acryl-base materials and so on, can
be used; including furthermore, one-component type adhesive
materials as well as two-component reactive type adhesive materials
and light-curable type adhesive materials, without any restriction
on the type indeed. After all, an important point is that viscosity
and other properties of the adhesive material are controlled in
order to make it possible to cover the motor stator side surface 65
of the case structural component 60, without any void part.
[0045] Usually, as shown in FIG. 3A and FIG. 3B, the motor stator
70 is pressed into the lower space of the case structural component
60 until the wire-wound coil 72 of the motor stator 70 contacts the
wall surface 65, and then the adhesive material 69 is fed through a
void space of the wire-wound coil 72 so that the adhesive material
69 is applied evenly all over the wall surface 65. By the way, the
motor stator 70 is pressed into the lower space while contacting an
outer circumference wall (hereinafter called a "radial-direction
wall 67") of the case structural component 60 and/or a shaft side
wall (hereinafter called a "shaft side wall 68") of the case
structural component 60. Therefore, the motor stator does not move
even without any adhesive material, and furthermore the motor
stator does not move while the adhesive material 69 is being
charged and/or hardened.
[0046] Thus, the adhesive material 69 covering the wall surface 65
may be placed, as FIG. 2 shows for example, so as to cover a
position of the stator yoke 71 included in the motor stator 70,
namely a position of the protruded pole part 711, so that an entire
part of the protruded pole part 711 adheres to and gets fixed to
the motor stator side surface 65 of the case structural component
60 with the adhesive material 69. Furthermore, the adhesive
material may be placed, as FIG. 4 shows for example, so as to have
a thickness that is thinner than a thickness of the stator yoke 71
included in the motor stator 70 so that only the wire-wound coil 72
adheres to and gets fixed to the motor stator side surface 65 of
the case structural component 60 with the adhesive material 69.
Still further, it is also possible, as FIG. 5 shows, to cover an
entire part of the motor stator 70 with the adhesive material. In
order to fix the motor stator 70 to the lower space of the case
structural component 60 by using the adhesive material 69, it is
possible only to drop the adhesive material at several spots for
each wire-wound coil 72 or each combination of the wire-wound coil
72 and protruded pole part 711. However, to surely restrain the
thin thrust-direction wall 66 from having any sympathetic
vibration, it is preferable that a configuration is made up so as
to have no exposure of the wall surface 65 and have the wall
surface 65 contacted by at least one of the adhesive material 69
and any structural component of the motor stator 70. In order to
surely restrain the thrust-direction wall 66 from having any
sympathetic vibration, it is preferable that the adhesive material
69 covers the wall surface 65 with thickness of the adhesive
material that is greater than 1.0 mm including thickness of the
thrust-direction wall 66.
[0047] Incidentally, sympathetic vibration of the case structural
component 60 mainly comes up at the thrust-direction wall 66, and
therefore no restriction exists on an adhesive material that covers
other sections including the radial-direction wall 67 and the shaft
side wall 68 so that various adhering configuration can be applied
for those sections. With the vortex pump 1 constructed as described
above, low-profile design can be realized as an entire profile of
the pump, and eventually a low-shaped vortex pump can be provided
while securing stable revolution of the pump for a long time.
[0048] Described next is another preferred embodiment of the
present invention. In a configuration shown in FIG. 5 described
above, the adhesive material 69 is charged so as to cover the motor
stator 70. Meanwhile, FIG. 6 is an explanatory drawing to show an
example of a configuration including an integral-type (which can
also be expressed as "embedded-type") case structural component 75
in which the motor stator 70 is embedded.
[0049] In a vortex pump of the present invention, as shown in FIG.
6, the integral-type case structural component 75, in which the
motor stator 70 is integrated with a case structural component, can
also be used as a structural component of the vortex pump 1. The
integral-type case structural component 75 is usually formed
through an integral molding process; in which a metal mold for
injection molding provided with a specified shape is prepared, and
the motor stator 70 is placed in the metal mold for injection
molding, and then a mold resin material is injected through an
injection gate into the metal mold to make up the integral-type
case structural component. Therefore, the integral-type case
structural component 75 shown in FIG. 6 corresponds to a
configuration in which the adhesive material 69 in the
configuration of FIG. 5 is replaced with the same material as a
structural resin material of the case structural component 60.
Incidentally, a structure of any other section of the vortex pump
of this configuration is the same as what is described by using
FIG. 1 and so on, and therefore the same reference numerals are
used in the drawing and explanation is omitted.
[0050] In the same manner as described above, a vortex pump using
the integral-type case structural component 75 is a pump in which a
fluid (gas or liquid) is introduced from the suction port 61 and
discharged from the discharge port 62; and the pump is equipped
with; the impeller 20 that includes the plurality of blades 22 at
an outer circumference and the rotor magnet 40 placed at an inner
circumference; the shaft 41 fixed at a center of the impeller 20;
the bearing component 50 (supplied as the couple of ball bearings
50a and 50b) placed at an outer circumference of the shaft 41; the
motor stator 70 placed under the impeller 20 and at an inner
circumference side of the rotor magnet 40; the integral-type case
structural component 75 having the suction port 61 and the
discharge port 62 that works to house the impeller 20 and
furthermore to embed the motor stator 70; and the lid component 10
placed on the integral-type case structural component 75 that
houses the impeller 20.
[0051] A feature of a vortex pump according to this configuration
includes; having the integral-type case structural component 75,
and thickness "T" of a wall (thrust-direction wall) 66 of the
integral-type case structural component 75 positioned at a side
dividing the impeller 20 and the motor stator 70, with which it
becomes possible to restrain sympathetic vibration of the
thrust-direction wall 66. In the integral-type case structural
component 75 of a configuration shown in FIG. 6, the thickness "T"
of the thrust-direction wall 66 is expressed as a distance between
the wall surface 65 of the wire-wound coil 72, positioned at a side
of the impeller, and a surface of a side facing the impeller 20 in
the motor stator 70. The vortex pump according to the configuration
does not have sympathetic vibration of the thrust-direction wall 66
caused. Even if the thickness "T" of the thrust-direction wall 66
is thin, sympathetic vibration of the thrust-direction wall 66 can
be restrained. Therefore, compact design and low-profile design of
the vortex pump can be achieved.
[0052] Described next are circular protruded sections (i.e.,
reference numerals of 31, 32, 55 and 56). As shown in FIG. 2, the
circular protruded sections (the reference numerals of 31, 32, 55
and 56) centered at the shaft 41 are placed at an outer
circumference section, which is outside a position including an
outer race of a ball bearing as the bearing component 50, and
including at least a lower surface of a motor stator side of the
impeller 20. The circular protruded sections play a sealing role in
preventing a lubricant material from evaporating or scattering away
into an outer circumference direction of the impeller 20 when the
bearing component 50 is supplied with the lubricant material, such
as grease and so on. The reason why the expression "at least" is
used in the above explanation is that the condition includes not
only a case where the circular protruded sections are placed at the
lower surface of the impeller 20 at the motor stator side but also
another case where the circular protruded sections are placed at
both the lower surface of the impeller 20 at the motor stator side
and a surface of another component facing the objective
surface.
[0053] Adequate condition is to have at least one circular
protruded section (at least one of a first protruded section 31 and
a second protruded section 32) at the lower surface of the impeller
20 at the motor stator side. However, it is preferable that;
particularly (1) at least one couple of protruded sections facing
each other are placed, like a couple of the first protruded section
31 and a third protruded section 55 or another couple of the second
protruded section 32 and a fourth protruded section 56; and still
further it is preferable that; (2) two or more couples of protruded
sections in which the protruded sections face each other are
prepared as FIG. 2 shows. These circular protruded sections (the
reference numerals of 31, 32, 55 and 56) play a sealing role in
preventing the lubricant material from evaporating or scattering
away, as described above, and the circular protruded sections also
have an effect on prevention against any fluid to get into the
shaft 41.
[0054] More specifically, as shown in FIG. 2, two circular-shaped
protrusion sections, i.e., the first protruded section 31 and the
second protruded section 32 are formed at a lower surface of the
motor stator side of the disk-shaped rotor yoke 30 included in the
impeller 20 while being provided with a specified clearance (for
example, a clearance of 1 mm). On the other hand, at an opposite
side facing the first protruded section 31 and the second protruded
section 32; two circular-shaped protrusion sections, i.e., the
third protruded section 55 and the fourth protruded section 56,
having the same circular-shaped profiles as the first protruded
section 31 and the second protruded section 32 have, are formed at
each position opposite to the first protruded section 31 and the
second protruded section 32 while being provided with a specified
clearance (for example, a clearance of 1 mm). A clearance between
the first protruded section 31 and the third protruded section 55
as well as another clearance between the second protruded section
32 and the fourth protruded section 56 are each approximately 200
microns. A first space 58 and a second space 59; surrounded by the
protruded sections of 31, 32, 55 and 56; function as a sealing
section 590. The sealing section 590 is preferably filled with a
lubricant material, such as grease and so on, as described above.
Filling the first space 58 with a lubricant material, such as
grease and so on, makes it possible to prevent evaporating or
scattering away of a lubricant material out of a bearing component
section at an inner side and furthermore to prevent a fluid coming
in out of an outer side and also preferably a liquid coming in.
Thus, the sealing section 590 prevents the lubricant material
charged in the second space 59 at the bearing component side from
evaporating or scattering away in order to secure good lubricating
condition of the shaft and the bearing component. Moreover, the
sealing section 590 can effectively prevent a fluid from getting
into the shaft 41.
[0055] In the embodiment shown in FIG. 2, the fourth protruded
section 56 is formed to be circular on a surface of the case
structural component 60 at a side of the rotor yoke 30, while the
third protruded section 55 is constructed by an upper end of a ring
component 54 mounted at a surface of the case structural component
60 at a side of the bearing component 50.
[0056] By the way, in FIG. 2, the sealing section 590 is formed at,
or in a vicinity of the bearing component. When the protruded
sections of the sealing section are formed at any other position,
e.g., at around a middle position toward a circumferential edge of
the rotor yoke 30, or at an outer circumference side; the sealing
section becomes preferred as far as run-out and tilt of the
impeller 20 are concerned. When the protruded sections are located
at an outer circumference position, a better effect is especially
expected. However, it is usually preferable that the sealing
section is formed at or in a vicinity of the bearing component, as
shown in FIG. 2. The reason is that forming the protruded sections
at such a position is relatively easier in terms of thickness of
components; and furthermore when the protruded sections are formed
at an outer circumference position, grease and so on of the sealing
section 590 becomes a resistance to revolving operation and creates
a load, so that effective revolving operation with low power
consumption is hampered.
[0057] Furthermore, although a configuration in which the circular
protruded sections are placed is explained as a preferred one in
the embodiment described above, a labyrinth structure including a
plurality of combinations of protruded sections and caved section
may be used instead of such a configuration.
[0058] Explained next is an effect of the present invention in a
case where a ball bearing is used as the bearing component 50. FIG.
7 is an explanatory drawing to describe a preload "F" given onto
the bearing component 50 constructed with the couple of ball
bearings of 50a and 50b that are stacked up. Outer circumference
rings of the ball bearings of 50a and 50b are fixed to the ring
component 54 mounted onto the case structural component 60 by using
an adhesive material and so on at a side of the bearing component
50, while inner rings of the ball bearings of 50a and 50b are fixed
to the shaft 41.
[0059] As described above, the center level in the thickness
direction of the rotor magnet 40 is located a bit higher than the
center level in the thickness direction of the stator yoke 71.
Therefore, while the impeller 20 is revolving, a downward force "F"
acts on the impeller. Since the force "F" acts so as to press the
shaft 41 downward, other downward forces "F1" and "F3" also act on
inner circumference rings of the ball bearings of 50a and 50b that
are fixed to the shaft 41. Furthermore, other downward forces "F2"
and "F4" also act on balls included in the ball bearings of 50a and
50b.
[0060] By operations of the forces "F1" and "F3 as well as "F2" and
"F4" described above, a load (preload) is given to upper contacting
sections "P" and "R" between the inner circumference rings and
balls included in the ball bearings of 50a and 50b, while a load
(preload) is given to lower contacting sections "Q" and "S" between
the inner circumference rings and balls included in the ball
bearings of 50a and 50b. Since the loads (preloads) given to the
upper contacting sections "P" and "R" as well as the lower
contacting sections "Q" and "S" stabilize revolving operations of
the ball bearings of 50a and 50b, revolution free from any play can
be realized.
[0061] In the bearing component 50 configured as shown in FIG. 7, a
ratio of length "L" of the bearing component to inner diameter "D"
thereof (LID) is usually 2 or greater. However, in a vortex pump of
the present invention, because of actions of the loads (preloads)
given to the upper contacting sections "P" and "R" as well as the
lower contacting sections "Q" and "S", revolution of the impeller
20 can be stabilized, and furthermore reduction in size and weight
can be realized. Consequently, it also becomes possible to make the
ratio "L/D" less than 2.0 (as a matter of course, it is possible to
make it 2.0 or greater).
[0062] While the foregoing description and drawings represent the
present invention, it will be obvious to those skilled in the art
that various changes may be made therein without departing from the
true spirit and scope of the present invention.
REFERENCE NUMERALS
[0063] 1. Vortex Pump [0064] 10. Lid Component [0065] 20. Impeller
[0066] 21. Blade Component [0067] 22. Blades [0068] 23. Grooves
[0069] 30. Rotor Yoke [0070] 31. & 32. Protruded sections
[0071] 36. Protrusion Edge Part [0072] 40. Rotor Magnet [0073] 41.
Shaft [0074] 50. Bearing Component [0075] 50a & 50b. Ball
bearings [0076] 54. Ring Component [0077] 55. & 56. Protruded
sections [0078] 58. First Space [0079] 59. Second Space [0080] 60.
Case Structural Component [0081] 61. Suction Port [0082] 62.
Discharge Port [0083] 63. Fluid Path [0084] 64. Lead Wire Path
[0085] 65. Motor stator side surface of the case structural
component [0086] 66. Wall of the case structural component
(Thrust-direction wall) [0087] 67. Outer circumference wall of the
case structural component (Radial-direction wall) [0088] 68. Shaft
side wall of the case structural component (Shaft side wall) [0089]
69. Adhesive Material [0090] 70. Motor Stator [0091] 71. Stator
Yoke [0092] 72. Wire-Wound Coil [0093] 75. Integral-type case
structural component [0094] 80. Substrate [0095] 90. Through-Hole
[0096] 91. Protrusion for Welding [0097] 92. Edge Surface [0098] P.
& R. Upper contacting sections [0099] Q. & S. Lower
contacting sections [0100] F, F1, F2, F3, & F4. Forces
* * * * *