U.S. patent number 3,614,275 [Application Number 04/876,247] was granted by the patent office on 1971-10-19 for control means for bidirectional rotary fluid motor system.
This patent grant is currently assigned to Curtiss-Wright Corporation. Invention is credited to Richard S. Eibsen.
United States Patent |
3,614,275 |
Eibsen |
October 19, 1971 |
**Please see images for:
( Certificate of Correction ) ** |
CONTROL MEANS FOR BIDIRECTIONAL ROTARY FLUID MOTOR SYSTEM
Abstract
A control means for a bidirectional, rotary fluid motor means
constructed and arranged to have porting and fluid working chambers
to provide rotation of a rotor in one direction or the opposite
direction. The control means comprises a control valve connected to
communicate with the fluid motor means and a pressurized fluid
supply means and a fluid exhaust or return means so that
pressurized fluid fills or "floods" the fluid motor, including the
ports and working chambers, in the neutral or null position of the
control valve to thereby cause equal and opposite torque forces on
the rotor and prevent rotation of the latter, and in another
operative position of the valve effect an imbalance of torque
forces on the rotor so as to cause rotation of the rotor in one
direction or the other with a minimum time lapse.
Inventors: |
Eibsen; Richard S. (Hillsdale,
NJ) |
Assignee: |
Curtiss-Wright Corporation
(N/A)
|
Family
ID: |
25367270 |
Appl.
No.: |
04/876,247 |
Filed: |
November 13, 1969 |
Current U.S.
Class: |
418/206.1;
417/315; 418/270; 418/210 |
Current CPC
Class: |
F01C
11/00 (20130101); F01C 21/18 (20130101) |
Current International
Class: |
F01C
11/00 (20060101); F01c 001/18 (); F01c 011/00 ();
F01c 021/12 () |
Field of
Search: |
;418/191,259,205,206,268,269,270,209,210 ;91/418,466 ;417/315 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Schwadron; Martin P.
Assistant Examiner: Cohen; Irwin C.
Claims
What is claimed is:
1. A hydraulic power-transmitting device comprising, in
combination, a bidirectional rotary liquid motor means having
housing means, rotor means defining with the housing means two sets
of working chambers, and a first suction and discharge port means
for one set of working chambers and second suction and discharge
port means for the other set of working chambers to deliver
pressurized liquid into the set of working chambers and exert a
torque force on the rotor means and effect thereby rotation of the
rotor means in one direction or the opposite direction depending on
which of said first and second suction and discharge port means
pass liquid into and from the sets of working chambers, and control
means comprising:
a. control valve means having first, second, and third fluid ports
and movable means coacting with said ports to control flow of
liquid therethrough;
b. uncontrolled pressurized liquid supply passage means
communicating with a source of pressurized liquid and with the
suction port means of said first suction and discharge port means
of the fluid motor means and with said first fluid port of the
control valve means;
c. uncontrolled exhaust passage means communicating with said
discharge port means of said second suction and discharge port
means of the liquid motor means and with the third fluid port to
pass spent pressurized liquid from the working chambers of the
liquid motor means;
d. control passage means communicating with the second fluid port
of the control valve means, the suction port means of said second
suction and discharge port means, and the discharge port of the
first suction and discharge port means of the liquid motor means;
and
e. said movable means of said control valve means coacting with
said first, second and third fluid port to communicate, in one
operative position, said first and second fluid port and thereby
affect rotation of the rotor means in one direction, in another
operative position terminate communication between said first and
second fluid ports and communicate the second fluid port with said
third fluid port to affect rotation of the rotor means in an
opposite direction, and in a neutral operative position of the
movable means close off pressurized liquid flow through the first,
second and third ports so that the communication between the
pressurized liquid supply passage and the exhaust passage means is
only through said suction port means of said first suction and
discharge port means and the discharge port means of the second
suction and discharge port means thereby maintaining said liquid
motor means in a flooded condition and providing substantially
balanced torque forces acting on the rotor means to prevent
rotation of the latter.
2. The combination of claim 1 wherein said movable means comprises
a slidable valve element movable relative to said first, second and
third fluid ports communicating with the supply passage means,
control passage means and exhaust passage means to vary the fluid
flow areas of the said first, second and third ports.
3. The combination of claim 1 wherein said fluid motor means is of
the balanced pressure slidable vane type.
4. The combination of claim 1 wherein said fluid motor means
comprises two unidirectional fluid motors disposed adjacent to each
other and connected to drive an output shaft in opposite
directions.
5. The combination of claim 4 wherein each of said unidirectional
fluid motors is of the gear type.
6. The combination of claim 1 wherein said fluid motor means
comprises a housing, a rotor disposed in the housing and carrying
radially extending, circumferentially spaced vanes slidable
radially relative to the rotor as the latter rotates within the
housing.
7. The combination of claim 1 wherein said control valve means
comprises a spool having lands and a groove disposed for
reciprocable movement relative to said fluid ports for controlling
fluid flow through said fluid ports.
Description
This invention relates to fluid power transmitting devices, and,
more particularly, to a control means for a bidirectional, rotary
fluid motor.
BACKGROUND OF THE INVENTION
In fluid-actuating systems which comprise rotary fluid motors, such
as the sliding vane type as exemplified in U.S. Pat. No. 2,719,512,
screw-and-gear type or the like, employed to effect the operation
or actuation of other devices, such as wing flaps or other control
surfaces of an aircraft, a time lag exists between the input signal
and the response of the system to that input signal. At least part
of this reaction time is attributable to the interstices between
components and other spaces in the fluid motors which provide
leakage flow paths and fluid voids which must be filled with
pressurized fluid before the fluid begins to become effective to
operate the fluid motors by overcoming the load thereon. This
delayed reaction time in some applications, such as in actuating
systems for aircraft, especially ultra-high-speed aircraft, is
obviously undesirable and increases the hazards of flying.
In the U.S. Pat. No. 3,016,021, to Rineer, the patentee recognized
the desirability of "flooding" a fluid motor to permit it to react
quickly to input signal, and achieved this result with a unique,
relatively complex, fluid motor in which the roller-type vanes
functioned as valve elements to effect rotation in different
directions in response to a control valve disposed in the fluid
exhaust of return conduits from the fluid motor.
Accordingly, it is an object of this invention to provide a control
means for a rotary fluid motor which permits the "flooding" of a
bidirectional rotary fluid motor of conventional, relatively simple
construction.
It is another object of the present invention to provide a control
means in combination with a rotary fluid motor of conventional
construction which enables the motor to switch from one direction
of rotation to another quickly in response to an input signal.
A feature of this invention is the interconnection of a
conventional bidirectional rotary fluid motor with a control means,
source of pressurized fluid and a fluid exhaust or return means so
that fluid pressure constantly exerts substantially equal and
opposite torque forces upon the rotor of the fluid motor in the
neutral or null position of a valve means of the control means to
thereby prevent rotation of the rotor and maintain the rotor under
the influence of these balanced opposing torque forces by keeping
the fluid motor fully pressurized or in a "flooded" condition. This
feature provides for holding the fluid motor against rotation and
provides rotation of the fluid motor, when its operation is
desired, within minimal reaction time.
SUMMARY OF THE INVENTION
Thus, the present invention contemplates a power-transmitting
device which comprises in combination, a novel control means and a
conventional bidirectional, rotary fluid motor having rotor means
connected to drive an output shaft in one direction or the opposite
direction and plurality of fluid ports for the passage of
pressurized fluid into and from the fluid motor. The control means,
including the control valve means, is provided for controlling the
flow of pressurized fluid to and from the fluid ports and thereby
the direction and speed of rotation of the rotor means of the fluid
motor. A pressurized fluid supply passageway means is connected to
continuously communicate a source of pressurized fluid with the
motor means through at least one of said fluid ports and the
control valve means. An exhaust fluid passageway means is provided
to communicate with the fluid motor means, through another of the
multiplicity of fluid ports, to exhaust pressurized fluid from the
fluid motor means and communicate with the control valve means. A
fluid passageway means is provided to communicate with the fluid
motor means, through two fluid ports other than the fluid ports to
which the fluid supply and the exhaust passageway means
communicate, and with the valve control means. The fluid control
valve means has a moveable valve element constructed and arranged
to control the intercommunication of the fluid supply passageway
means, exhaust passageway means and the control passageway means
and provide, in the neutral or null position, for the interruption
of communication between the aforesaid three fluid passageway
means.
In this neutral position of the control valve means, a fluid
pressure in the control passageway means is provided which is the
average of the fluid pressure in the supply and exhaust passageway
means so as to exert a total torque upon the rotor means counter to
and substantially equal in magnitude to the torque exerted by the
fluid pressure conducted to the rotor means by the supply
passageway means. With the fluid pressure forces acting upon the
rotor means in balance, the fluid motor is nonoperative. The
movement of the valve element of the control valve means from the
neutral or null position to communicate the control passageway
means with the supply passageway means and thereby conduct supply
fluid to the fluid motor, provides for the exertion of a total
torque force upon the rotor means counter to and substantially
double the torque force exerted by the supply fluid conducted to
the fluid motor means by the supply passageway means. This
imbalance of pressurized fluid acting upon the rotor means causes
the latter to rotate, assuming such supply fluid pressure is
sufficient to overcome the load upon the fluid motor means. The
movement of the valve element of the valve control means to another
position, whereby communication is effected between the fluid
control passageway means and the exhaust passageway means so that
the fluid pressure in the control passageway means is reduced to
exhaust fluid pressure, an unbalanced torque force results from the
fluid delivered to the rotor means by the supply passageway means
so that rotation of the rotor means is achieved in a direction
opposite to the direction of rotation effected in the
first-mentioned nonneutral position of the control valve means.
The control valve means may be constructed and arranged to modulate
fluid flow to the fluid motor means to control the speed of the
fluid motor in either direction of rotation.
Since pressurized supply fluid is continuously delivered to the
motor means, through the supply passageway means, and from the
fluid motor means, through the exhaust passageway means in the
neutral or null position of the control valve means, the fluid
motor is maintained in a "flooded" condition, thereby enabling the
fluid motor to rapidly respond to the actuation of said valve
control means.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more fully understood from the following
description thereof when considered in connection with the
accompanying drawing wherein two embodiments of the invention are
illustrated by way of example and in which:
FIG. 1 is a diagrammatic view of one embodiment of the present
invention; and
FIGS. 2 and 3 are diagrammatic illustrations, similar to FIG. 1,
showing other operative positions of the control valve;
FIG. 4 is a diagrammatic drawing of another embodiment of this
invention; and
FIGS. 5 and 6 are views, similar to FIG. 4, showing additional
operative positions of the control valve shown in FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now referring to the drawings and more particularly to FIGS. 1, 2
and 3, inclusive, in which one embodiment of the
fluid-power-transmitting device according to this invention is
diagrammatically illustrated, the reference numeral 10 generally
refers to the fluid-power-transmitting device which comprises a
fluid motor 11 and a control means of which control valve 12 forms
a part.
The fluid motor 11 is of the conventional bidirectional sliding
vane type which comprises a rotor 13, carrying slidable vanes 14,
journaled for rotation within a cavity of a housing 15 so that the
distal end edges of the vanes engage the inner surface of the
housing cavity, the adjacent vanes and housing cavity defining
working chambers into which pressurized fluid is introduced and
exhausted to apply a torque force to the rotor. The fluid motor 11
may be of the type, such as exemplified in the U.S. Pat. No.
2,719,512, to Kovach, wherein the cavity of housing 15 is provided
with two recesses, A and B, and four ports, 16, 17, 18 and 19,
arranged so that ports 16 and 17 communicate with recess 19 while
ports 18 and 19 communicate with recess B. With this construction,
the fluid motor is provided with two sets of working chambers which
by control of pressurized fluid flow into and from the ports 16,
17, 18 and 19, will achieve rotation of rotor 12 in a clockwise or
counterclockwise direction. In accordance with the present
invention, control means, including control valve 12, is provided
to control direction and speed of operation of fluid motor 11.
The control valve 12 may be a three -way valve of any suitable
construction, such as a spool valve, sleeve valve or the like. For
illustration purposes only, control valve 12 is schematically shown
in the drawings as a spool valve comprising a cylindrical housing
20 and an axially moveable valve element 21. The valve element has
two spaced land portions 22 and 23 which define therebetween an
annular groove 24. The housing 20 is provided wit three spaced
ports 25, 26 and 27 which communicate with the interior of the
housing. As will be readily apparent hereinafter, valve element 21
and the ports 25, 26 and 27 are so arranged and dimensioned that
axial movement of valve element 21 will control communication
between ports 25, 26 and 27. In addition to control valve 12, the
control means includes pressurized fluid supply passage means or
conduit 28, pressurized fluid exhaust passage means or conduit 28,
pressurized fluid exhaust passage means or conduit 29, and a
control passage means or conduit 30.
The pressurized fluid conduit 28 is in communication with a source
of pressurized fluid (not shown), such as a pump or an accumulator,
and with ports 25 of control valve 12 and port 16 of fluid motor
11. Fluid conduit 28 communicates with port 25 of control valve 12,
through a branch conduit 9.
The pressurized fluid exhaust conduit 29 is in communication with
port 18 of fluid motor 11 and port 27 of control valve 12, via
branch conduit 32, and with atmosphere or the recirculation pump,
receiver or other similar component if the fluid system is a
closed-recirculation system.
The control conduit 30 is connected to be in communication with
port 26 of control valve 12 and with ports 17 and 19, through
bifurcated branch portions 33 and 34, respectively.
While control valve 12 is shown hereinafter and described as
dimensioned so that in the neutral position, the land portions of
the valve element 21 close ports 25 and 27, it is within the
purview of the present invention to proportion valve element 21 so
that in the neutral position balanced communication exists between
ports 25 and 27. In other words, without departure from the scope
and spirit of the present invention, land portions 22 and 23 of
valve element 21 may be constructed so as not to cut off in the
neutral position communication between ports 25 and 27, but provide
balance fluid flow therebetween.
As best seen in FIG. 1 when control valve 12 is in the neutral or
null position, land portions 22 and 23 close ports 25 and 27 so
that no communication exists between ports 25, 26 and 27. In this
position, pressurized fluid, such as liquid or gas, is conducted to
port 16 of fluid motor 11 and thence into chamber A. This
pressurized supply fluid flow, at a pressure of P, fills the
interstices between the components of the fluid motor (leakage flow
paths) and other spaces or voids and becomes "flooded." The
pressurized fluid also flows into control conduit 30, via ports 17
and 18, to create a back pressure at each of the ports 17 and 18 of
approximately one-half of the fluid pressure P at port 16. Since
the fluid motor, through port 18 is in constant communication, via
exhaust conduit 29, with a point of low fluid pressure, a constant
flow of pressurized fluid through the fluid motor is provided and
air or other gaseous fluids are not trapped in the fluid motor.
Thus, the fluid motor is maintained in a "flooded" condition. Since
the fluid pressure P, at port 16, acts to urge rotor 13 in a
clockwise direction and the fluid pressure, at ports 17 and 19,
exert a torque force on rotor 13 which is substantially equal and
counter to the torque force imposed on the rotor by the fluid
pressure at port 16, the forces acting on the rotor are balanced
and rotor 13 remains stationary.
Actuation of control valve 12 to the position shown in FIG. 2, by
slidable movement of valve element 21 to the left from the neutral
position illustrated in FIG. 1, causes rotor 13 of fluid motor 11
to rotate in a counterclockwise direction. As shown, land portion
22 opens or uncovers port 25 in control valve 12 to bring port 25
into communication with port 26, via groove 24 so that fluid, at
supply pressure P, exerts in chambers A and B through ports 17 and
19 of fluid motor 11, a torque force on rotor 13 in a
counterclockwise direction. Since supply pressure P is exerted on
the rotor in both chambers A and B for a total pressure of 2P, the
supply pressure P exerting a clockwise torque on rotor 11 is
overcome and rotor 11 is rotated in a counterclockwise direction.
The response of the rotor to this input signal is very rapid
because the motor is in a saturated or "flooded" condition and no
reaction time is consumed in filling the leakage flow paths or
voids of the fluid motor before the force is effective to achieve
rotation of rotor 13.
To quickly effect clockwise rotation of rotor 13 of fluid motor 11,
control valve 12 is actuated to the right to the position shown in
FIG. 3 wherein land portion 22 closes port 25 and land portion 23
uncovers or opens port 27. In this position, the fluid in control
conduit 30 is brought into communication with exhaust conduit 29,
via groove 24 and branch conduit 32. This communication and the
consequent "dumping" of fluid in control conduit 30 provides,
through port 16, a supply fluid pressure P which exerts a torque
urging rotor 13 in a clockwise direction.
The fluid pressure in control conduit 30 is now at exhaust pressure
and provides only negligible resistance to the rotation of rotor 13
in a clockwise direction.
The speed of rotation of rotor 13 in both the clockwise and
counterclockwise direction is obviously achieved by positioning
valve element 21 in any position between the neutral position and
the position where ports 25 and 27 are fully open. Obviously, the
more land portions 22 and 23 of valve element 21 restrict the flow
area of ports 25 and 27 the slower will be the rotation of rotor
13. Thus, actuation of valve element 21 controls both direction and
speed of rotation of rotor 13 and, hence, the direction and speed
of an output shaft 31 to which rotor 13 is drivably connected.
In FIGS. 4, 5 and 6, a fluid-power-transmitting device 35 according
to another embodiment of this invention is shown and which differs
from the fluid-power-transmitting device 10 herein described and
illustrated in FIGS. 1, 2 and 3 in that two motors of a
unidirectional type are employed to effect the rotation of an
output shaft instead of a single bidirectional fluid motor 11. The
parts of fluid-power-transmitting device 35, corresponding to like
or similar parts of transmitting device 10, will be designated by
the same reference numbers, but with the suffix A added
thereto.
The power-transmitting device 35 comprises two fluid motors 36 and
37 of a unidirectional type, such as an internal gear motor in
which two meshing gears 38 and 39 are supported in a housing 40 for
rotation, gear 38 being connected to rotate an output shaft 31A. In
accordance with this invention a control means, including a control
valve 12A, is provided to control the direction and speed of
rotation of output shaft 31A.
The control valve 12A may be of any suitable type for control of
flow through three ports and, since it is shown for illustration
purposes only as being of identical construction to control valve
12, it will not be described in detail. As in the device herein
described and shown in FIGS. 1 to 3, in addition to control valve
12A, the control means includes a pressurized fluid supply passage
means or conduit 28A, pressurized fluid exhaust passage means or
conduit 29A, and a control passage means or conduit 30A.
The supply passage means 28A is connected to communicate with fluid
motor 36, via port 16A, to a source (not shown) of pressurized
fluid at a pressure P. Supply passage means is also in
communication with control valve 12A, via port 25A and branch line
or pipe 9A.
The exhaust passage means 29A is connected to fluid motor 37 and to
atmosphere or recirculating means (not shown) to conduct fluid from
motor 37 to the latter.
The control passage means 30A is connected to communicate with
fluid motors 36 and 37, via ports 17A and 19A, respectively, and
with control valve 12A through port 26A.
In the operation of the power-transmitting device 35 with the
control valve 12A in the neutral position shown in FIG. 4, output
shaft 21A is stationary. As in power-transmitting device 10, fluid
supply passage means 28A is constantly supplying fluid at a
pressure P to fluid motor 36 to "flood" the motor and control
passage means 30A. Since control valve 12A is positioned to close
ports 25A and 27A, flow of fluid, through control passage means
30A, is closed off, except through fluid motor 37, via port 19A.
With passage means 30A in communication with exhaust passage means
29A, through fluid motor 37, the latter is also maintained in a
"flooded" condition. The fluid in control passage means 30A,
through port 19A of fluid motor 37, exerts a torque force, through
gears 38 and 39, on output shaft 31A in a direction counter and
substantially equal to the torque force exerted on the output shaft
by the fluid entering fluid motor 36 via port 16A. With the torque
forces acting on output shaft 31A balanced, the output shaft is
stationary.
To effect rotation of output shaft 31A in a clockwise direction,
valve element 21A is actuated to the left from the position shown
in FIG. 4 to the position illustrated in FIG. 5. The land portion
22A clears port 27A while land portion 23A maintains port 25A
closed. In this position, control passage means 30A is brought into
communication with exhaust passage means, via ports 26A and 27A, so
that fluid in control passage means is released or "dumped" to the
exhaust passage means. When the fluid pressure in control passage
means falls below supply pressure P and no longer exerts a torque
force, through gears 38 and 39, on output shaft 31A in fluid motor
37 counter to that of the fluid in fluid motor 36, output shaft 31A
is rotated in a clockwise direction. Any fluid flow through fluid
motor 37 from control passage means to exhaust passage means 29A,
by way of ports 19A and 18A, exerts only a negligible torque force
counter to the rotation of output shaft 31A.
To reverse the rotation of output shaft 31A, valve element 21A of
control valve 12A is moved to the right to the position shown in
FIG. 6. In this position of valve element 21A land portions 22A and
23A close port 27A and open port 25A, respectively, so that supply
passage means 28A is brought into communication with control
passage means 30A. With the control passage means in communication
with supply passage means, the fluid pressure in control passage
means 30A rises to substantially a fluid pressure of P. Since the
fluid entering fluid motor 36, via port 17A, is at a pressure
substantially equal to the supply pressure P of the fluid entering
fluid motor 36, via port 16A, the torque forces acting upon output
shaft 31A in fluid motor 36 are substantially balanced. With
control passage means communicating with exhaust passage means 29,
through fluid motor 37, the fluid at supply pressure P flows into
the fluid motor, via port 19A, to exert a counterclockwise torque
force, through gears 38 and 39, on output shaft 31A. Since the
torque forces are balanced in fluid motor 36, output shaft 31 will
be rotated by fluid motor 37 in a counterclockwise direction.
To regulate the speed on the output shaft 31A in either direction
of rotation, valve element 21A is positioned to control the flow
areas of ports 27A and 25A between the fully opened and closed
positions shown in FIGS. 5 and 6.
It is believed now readily apparent that the present invention
provides a control means for a power-transmitting device which
permits the use of a conventional fluid motor means to achieve
bidirectional rotation and rapid response to an input signal to
change the direction of rotation.
Although two embodiments of the invention have been illustrated and
described in detail, it is to be expressly understood that the
invention is not limited thereto. Various changes can be made in
the arrangement of parts without departing from the spirit and
scope of the invention as the same will now be understood by those
skilled in the art.
* * * * *