Axially balanced, adjustable volume rotary machine and drive system utilizing same

A rotary machine usable as a pump, compressor, turbine or motor, for example. Rotating piston cylinders have radially movable pistons therein and the cylinders are mounted within a control ring and a housing. The control ring is tangentially pivoted within the housing to vary the volume flow through the machine and the torque application transmitted by a shaft, as well as the direction of flow through the machine. Pressure fluid operated balancing pistons are used to counter the axial thrust placed on the rotor by liquids applied to the rotor, regardless of the direction of flow through the machine.

BRIEF DESCRIPTION OF THE INVENTION 
1. Field of the Invention 
This invention relates to rotary piston pumps and motors and the like. 
2. Prior Art 
Rotary pumps and motors have long been known. These machines have generally 
included a stator and a rotor and have used either movable vanes or 
pistons to compress or to be driven by liquid passed through the machines. 
U.S. Pat. No. 1,156,816, for example shows a rotary machine usable as 
either a pump or a motor. In the disclosed machine vanes are carried by a 
rotor and serve to compress or to be driven by liquid moving through the 
machine. Machines of this type, with vanes, have been used in the past, 
but have not, to my knowledge, proven satisfactory for use where high 
pressures, i.e. of at least 4500 p.s.i. are involved. 
U.S. Pat. No. 2,164,888, discloses a rotary machine that utilizes 
reciprocating pistons. U.S. Pat. No. 2,164,888 discloses a variable 
delivery pump wherein the reciprocating pistons operate within a pivoted 
control ring. Liquid is supplied to and exhausted from the piston 
cylinders through a central axial passage system. The control ring 
position is controlled by a screw and an opposing spring biased sleeve 
member. A control knob on the screw is marked with a graduation so that a 
central position of the control ring in the machine housing can be 
determined. Turning of the knob and screw will then move the control ring 
in one direction beyond the centered position. The direction of flow 
through the pump is determined by which side of the center of the shaft 
the ring has been displaced. The degree of displacement of the control 
ring in either direction past the centered position will control the 
volumetric flow through the pump. 
SUMMARY OF THE INVENTION 
Principal objects of the present invention are to provide a rotary machine 
usable as either a pump or a motor and that is reversible in operation to 
change from a pumping function to a motor function and vice versa. 
Other objects are to provide a rotary machine that can provide for variable 
flow control in either a pump or motor mode and wherein the volumetric 
flow can be readily regulated. 
Still other objects are to provide a rotary machine that can be 
inexpensively constructed, easily assembled and that will include a 
balanced rotor in either a pump or a motor mode, to thereby minimize wear 
and to increase the life expectancy of the machine, while maintaining a 
central input or output shaft axially fixed. 
Principal features of the invention include a rotor mounted to have 
movement axially along an output shaft while being rotatable with the 
shaft; flow ports through a machine housing adapted to sequentially align 
with rotor ports interconnecting the piston chambers with one rotor face; 
a thrust plate carried by an opposite rotor face; pressure responsive 
balance pistons pressing against the thrust plate at sides opposite to the 
flow ports; and means for applying the pressures developed at the flow 
ports to oppositely acting ones of the balance piston. 
Additional objects and features of the invention will become apparent from 
the following detailed description and claims, taken together with the 
accompanying drawing showing a preferred form of the invention.

DETAILED DESCRIPTION 
Referring now to the drawing: 
In the illustrated preferred embodiment, the rotary machine of the 
invention is shown generally at 10. As shown, the machine includes a front 
housing plate 11, a rotor 13, a thrust plate 14, and a rear housing plate 
15. 
A central shaft 16 has one end journaled by a bearing 17 positioned in a 
recess 18 provided therefor in the front housing plate 11 and is journaled 
by a bearing 19 through the rear housing plate 15. The rotor 13 is spline 
connected at 20 to the shaft 16 and is slightly movable axially along the 
shaft while being rotatable therewith. Washers 21 encircle the shaft at 
opposite sides of the rotor 13 to limit the axial movement of the rotor on 
the shaft and split rings 22, snapped into grooves 23 in the shaft, hold 
the washers 21 in place. 
A pair of flow ports 24 and 25 are spaced at opposite sides of the 
centerline through the shaft and extend through the front housing plate to 
terminate in curved slots 26 and 27, respectively, formed on the inside 
face of the front housing plate. 
The rotor 13 has a plurality of radial cylinders 28 formed around the 
periphery thereof and extending thereinto. A port 29 through one face of 
the rotor intersects each cylinder 28. The ports 29 are elongate and are 
curved to form arcuate slots. In a preferred embodiment eleven cylinders 
28 and ports 29 are provided, but it should be apparent that more or fewer 
such cylinders and ports can be provided and since they are identically 
constructed only two such structures are here illustrated. 
A piston 30 reciprocates in each cylinder 28 and each piston has a ball 31 
formed on an end projecting outwardly of the cylinder. A shoe 32 is 
mounted to each ball 31 by a socket 32a of the shoe. Each shoe includes, 
in addition to the socket 32a, a follower 33 that is arcuately curved to 
correspond to the inner curve of a control ring 34, and has outwardly 
extended flanges 35 and 36 that are adapted to be engaged by shoe rings 37 
and 38, respectively. 
The control ring 34 forms a ring around the rotor 13 and the pistons 30 and 
shoes 31 carried thereby and is tangentially mounted by a pivot pintle 39 
that extends through a control ring, and that has its ends journaled in 
bearings 40 and 41, respectively mounted in openings provided in the front 
and rear housing plates 11 and 15. 
Shoe rings 37 and 38 are loosely fitted inside the control ring and 
respectively include flanges 42 and 43 that extend beyond the flanges 35 
and 36 to slidably hold the followers 33 between the control ring 34 and 
the flanges 42 and 43. 
The control ring is positioned within a larger central housing ring 44 and 
the bolts 45 inserted through the front housing plate 11 and the central 
housing ring 44 are threaded into the rear housing plate 15 to clamp the 
front housing plate, central housing ring and rear housing plate together. 
So arranged, the control ring is able to swing from one side to the other 
within the central housing ring, as will be hereinafter further described. 
A port 46 through each piston 30 communicates with a port 47 through the 
shoe such that pressure in the piston cylinder is communicated through the 
ports to the face of the follower 53 and between the follower and the 
control ring 34. 
The thrust plate 14 encircles the shaft 16 and fits flat within a recess 48 
provided therefor in the rotor 13. The thrust plate is adapted to be acted 
on by thrust plate engagement means, in opposition to the pressure of 
liquid moving into and out of the cylinders. 
The thrust plate engagement means includes a pair of pistons 49 (only one 
of which is shown in FIG. 2) positioned in spaced apart bore holes 50 
(only one of which is shown) provided therefor in the rear housing plate. 
The bore holes 50 are located so that force applied through the pistons 
therein will be opposite to force applied at the port 24 and are opposite 
the ends of the curved slot 26. Similarly another pair of pistons 51 (only 
one of which is shown in FIG. 2) are positioned in spaced apart bore holes 
52 (only one of which is shown in dotted lines) provided therefore in the 
rear housing plate. The ports 52 are located so that force applied through 
the pistons therein will be opposite to force applied at the port 25 and 
are opposite the ends of the curved slot 27. 
Each of the pistons 49 and 51 is recessed at 53 to receive one end of a 
spring 54, th other end of which abuts the end of the bore hole in which 
the piston is positioned. At the end opposite spring 54, each piston is 
made concave at 55 to receive a convex projection 56 formed on a thrust 
shoe 57. The ball and socket arrangement thus formed between the piston 
and the shoe allows a flange 58 on a face of the shoe to be flush against 
the thrust plate during all positions and movement of the thrust plate 
with the rotor 13. 
A passage 59 through each shoe 54 is aligned with a passage 60 through the 
piston and communicates the face of each shoe, inside the flange 58 with 
the recess 53 in which the spring 54 is located at the rear of each 
piston. 
Ports 61 in the rear housing plate communicate the bore holes 50 behind 
pistons 49, through ports in the central housing ring and ports 63 in the 
front housing plate with the flow ports 24. Similarly, ports 64 in the 
rear housing plate communicate the bore holes 52 behind the pistons 51 
with ports 65 through the central housing ring, ports 66 in the front 
housing plate and the flow port 25. 
Actuators 70 and 71 are mounted by bolts 72 to the central housing ring 44 
and provide a means whereby the control ring 34 is pivoted around the 
pintle 39. 
The actuators may be of the mechanical type shown in U.S. Pat. No. 
2,164,888 for example, or preferably are fluid operated, such as is 
hereinafter described. In either case, the actuators are mounted to be 
opposite one another at opposite sides of the central housing ring and 
ninety degrees around the central housing from the pivot pintle 39. The 
actuators are adapted to engage the rotor and to pivot it from side to 
side within the central housing ring 44. 
Shaft 16 has an axial bore hole 73 extending partially therethrough and 
transversely extending intercept ports 74 and 75. So arranged, oil flowing 
through the thrust plate engagement pistons and thrust shoes can lubricate 
the bearing 19, and then flow through port 75, bore hole 73 and port 74 to 
lubricate bearing 17. 
In operation, the position of the control ring 34, as set by the actuators 
70 and 71, regulates the unit and the volume of flow through the unit and 
the direction of rotation of the rotor. Thus, if the inlet port 25 is 
connected to a reservior of oil for example, upon rotation of the shaft 16 
the pistons will be moved in or out of the cylinders 28 in accordance with 
the position of the control ring 34 since each shoe is held close to the 
inner surface of the control ring centrifugally while being guided by the 
shoe rings 37 and 38. 
As the shaft 16 and rotor are turned it will be apparent that fluid will be 
drawn into those piston cylinders connected to the inlet port 25 by the 
curved slot 27 and the ports 28 of the cylinders aligned with inlet 27 and 
wherein the pistons are moving out of the rotor. The entering fluid is 
then compressed as the rotor turns and the pistons are moved into the 
rotor, with the compressed fluid being discharged under pressure from the 
cylinders as the ports 28 thereof come into alignment with the curved slot 
26 at the end of flow port 24. The control ring may be positioned, as 
necessary to allow either port 24 or 25 to serve as an inlet port and the 
other said port an outlet port and to allow for the reversal of rotation 
of the shaft 16. 
When the unit is used as a motor to drive the shaft 16, fluid, under 
pressure enters the cylinders connected to the inlet port 24 or 25 acts 
against the pistons 30 and rotor 13 and rotates the rotor such that the 
pistons will be moved out with respect to the rotor. The fluid is then 
discharged from the cylinders as the ports 29 come into alignment with the 
curved slot formed on the inside of the front housing and connected to the 
other port 24 or 25, serving as the outlet port. 
Nipples 80 and 81, fixed to the housing 11, provide means for respectively 
connecting fluid lines to the ports 24 and 25. O-rings 82, seated in 
grooves 83, provided therefor in the nipples seal the nipples to housing 
11. Other O-rings 84 and 85 fit in grooves provided therefore in the faces 
of the central housing ring to prevent loss of fluid between the end 
plates and the central housing ring. Still other O-rings 86 fit in grooves 
around each piston 47 and 51 of the thrust plate engagement means. The 
O-rings 86 allow the pistons to move, as required, but prevent leakage of 
fluid between the pistons and the walls of the bore holes provided 
therefor in the rear housing plate. 
During rotation of the rotor oil in the piston cylinders is centrifugally 
forced through the ports 46 and 47 to provide a lubricating film for the 
shoes 32 as they move within the control rings 34. Radial slots 87 allow 
the oil to move from the inside of the control ring past lands 88 formed 
on the face of the rotor and into ring shaped lubrication grooves 89 on 
the rotor face but outwardly of the slots 26 and 27. At the same time 
ports 90 and 91, spaced around the rotor allow oil to move into a 
lubricating groove 92 inside the grooves 26 and 27. This greatly reduces 
the friction between the rotor and the front housing plate. 
As has been previously noted, the pressure present at the flow ports and 
acting to force the rotor against the rear housing plate is also applied 
to the thrust plate engagement means to balance the applied forces at the 
flow ports. The springs 54 lightly bias the pistons 49 and 51 and socketed 
shoes 57 into engagement with the thrust plate 14 and hold the thrust 
plate in engagement with the rotor 13. 
If a high pressure is present at flow port 24, the same high pressure will 
be communicated through the ports 63, aligned ports through the central 
housing ring and ports 61 in the rear housing plate to the rear of pistons 
49 and the rotor 13, between the flow port 25 and the pistons 49 is held 
in an axially balanced position. If, at the same time, a low pressure is 
present at the flow port 24 the same low pressure will be communicated 
throgh ports 66, 65 and 64 to the rear of pistons 51 to hold the rotor 13 
between flow port 25 and the pistons 51 in an axially balanced condition. 
Naturally, if the high and low pressures are reversed at the flow ports, 
the same balanced condition of the rotor is maintained. 
The axially balanced adjustable volume rotary machine herein described has 
been found to be very satisfactory for use where high pressures of at 
least 4500 p.s.i. are required. Because of the axially balanced 
configuration and rotor lubrication arrangement, little wear occurs to the 
pump and it has been found that exceptionally long life can be achieved 
for the machine. 
The machine has been found to be ideally suitable for use in the driving of 
automotive vehicles and particularly to electro-hydraulic vehicles. 
As shown in FIG. 3, the machine 10 is well suited for use in systems having 
a prime mover and requiring a supplemental acceleration boost. As shown, 
the machine 10 is arranged in series with an electric motor 100 to power 
the drive wheels 101 of the vehicle, not shown, through a differential 
unit 102 and axles 103, but it will be apparent that the same system could 
be used to drive other loads, as well. 
In the system as schematically illustrated, the initial energy for 
accelerating the load comes from the batteries 105. To initiate such 
acceleration, the switch 106 is moved to a forward drive position, 
completing a circuit through contact 107 and placing the system in a 
forward operation mode. 
The accelerator pedal 108 is depressed, and upon the first movement of the 
pedal operates through a controller 109 to move a contactor switch 110 
such that a circuit is completed through a contact 110a to the reversible 
electric drive motor 100 to drive it in a forward direction and to thereby 
accelerate and drive the load, i.e., the wheels 101. 
When it is desired to stop or brake the vehicle the brake pedal 111 is 
depressed. The initial movement of the brake pedal closes switch 112 and 
continued movement of the brake pedal will operate the usual vehicle 
brakes, not shown, in conventional fashion. 
Closing of switch 112 completes the circuit to a solenoid 113 that controls 
operation of a two-position, three-way, normally open valve 114. In its 
"normally open" position, i.e., when solenoid 113 is deenergized, fluid 
from a fluid operated actuator 70 of the machine 10 is exhausted through a 
line 115 and the valve 114 to a reservoir 116. As will be further 
explained, when the solenoid 113 is energized, the valve is operated to 
allow high pressure fluid therethrough, and through the line 115 and a 
variable restrictor 117 in the line 115 to the actuator 70. 
In the system shown, both the actuators 70 and 71 are fluid operated. 
Actuator 70 comprises a fluid cylinder having a piston 118 therein and a 
piston rod 119 projecting therefrom through the central housing ring of 
machine 10 to engage the control ring 34 of the machine 10. Fluid is 
supplied to and exhausted from the back of the piston 118 by the line 115 
and a spring 121 within the actuator housing normally biases the piston to 
move the piston rod against control ring 34. 
Actuator 71 comprises a fluid cylinder with a piston 122 therein having a 
cross-sectional area somewhat smaller than that of piston 118 and a piston 
rod 123 projecting therefrom through the central housing ring of the 
machine 10 and into engagement with the control ring 34. Fluid is supplied 
to and exhausted from the actuator 70, behind the piston 121 through a 
line 124 having a variable restrictor 125 therein. 
When valve 114 is operated to exhaust fluid from actuator 70, the valve, at 
the same time, cuts off flow of fluid, under pressure to the actuator. 
The spring 121 moves the piston 118 to extend the piston rod 119 and to 
force the control ring 34 over center in the direction of the actuator 71. 
The rotation of the shaft 16 of the machine 10, caused by the turning of 
wheels 101, then causes the machine to begin pumping oil from reservoir 
116 through flow port 25 and out the flow port 24, under pressure, as has 
been heretofore described. The discharging oil, under pressure is 
communicated through the variable restrictor 120 and line 124 to the back 
of piston 122. The high pressure, acting on the piston 122 expels the 
piston rod 123 and moves the control ring 34 back towards its centered 
position, thereby decreasing the pumping action of the machine 10 until 
only a minimum pressure output results. The minimum pressure output is 
regulated by the balancing pressure required at the back of piston 122 to 
move the control ring to an essentially centered position and is 
transmitted through line 125, a pilot operted check valve 126, a check 
valve 127, a filter 128 and throughout the high pressure portion of the 
system, shown generally at 129. The minimum pressure is thus always 
present in the high pressure portion of the system and is available to 
operate the controller 70 when the brake pedal 111 is first actuated. 
As previously noted, when the brake pedal 111 is first actuated it 
completes a circuit to energize the solenoid 113 and to permit the 
available high pressure in line 130 to be supplied through line 115 to the 
back of piston 118. The high pressure acting on the back of piston 118 and 
the spring 121 bias the piston 118 to expel the piston rod 119 and to move 
the control ring of machine 110 overcenter towards the actuator 71. The 
variable restrictor 117 controls the rate of pressure application to the 
back of piston 118 and therefore the rate at which piston rod 119 is 
expelled and the control ring is moved. 
As the piston 118 is moved and the piston rod 119 is expelled it overcomes 
the biasing force of the same fluid acting on the smaller piston and the 
control ring is moved. 
As the control ring moves off center towards actuator 71, the machine pumps 
fluid from the reservoir 116 through flow port 25, out flow port 24 and 
into line 125. The flow is then through the pilot operated check valve 
126, check valve 127, filter 128, and into line 130. At the same time the 
flow is through an excess pressure responsive valve 131 and into an 
accumulator 132. During such braking, the action of the wheels in driving 
the machine 10 as a pump (through the axle 103 differential 102, and shaft 
16) causes the fluid to be pumped from reservoir 116 into the accumulator, 
as previously described. The accumulator preferably utilizes a 
compressible gas as a spring and the fluid pumped therein will compress 
the gas as the pressure in the system is increased. As the pressure in the 
system increases the vehicle will decelerate due to the energy of the 
inertia of the vehicle being absorbed by the gas. As the vehicle comes to 
a stop the pumping action of the machine 10 will stop. At this time the 
pilot operated check valve 126 prevents reverse flow from the accumulator 
chamber through the machine 10. 
If the braking cycle just described has continued for a sufficiently long 
time to allow a predetermined pressure to have built up in the accumulator 
132 and in line 130, for example 2500 p.s.i., the pressure will close a 
pressure switch 134. 
Thereafter, if the accelerator pedal is again depressed, the initial 
movement will act through controller 109 to close the contactor switch 110 
with contact 110a. At the same time a switch 135 is operated by the 
accelerator pedal to furnish power from the power supply through the 
closed pressure switch 134 to activate a solenoid 136 of a valve 137. 
When solenoid 136 is energized it operates valve 137 to allow high pressure 
fluid from line 130 to pass therethrough and into a line 138 leading to 
the pilot operated check valve 126. The high pressure from line 138 
unseats the check valve of valve 136 to allow from the accumulator 132, 
through excess flow valve 131 by pass line 139 and the check valve 140 
therein around the filter 128 and check valve 127, the pilot operated 
check valve 126, line 125, port 24, machine 10 and port 25 to the 
reservoir 116. At the same time, the time, the high pressure is 
transmitted through orifice 125 and line 120 to the back piston 122 of 
actuator 71. Also at this time, the valve 114 is operated to place the 
actuator 70 in connection with the reservoir 116. Consequently, the 
smaller piston 122 is moved and the piston rod 123 is expelled to overcome 
the force of spring 121 and to move the control ring 34 over center 
towards the actuator 70. The machine 10 then acts as a motor to cooperate 
with the motor 100 in driving the wheels 101. 
The operation of the machine 10 as a motor continues until the pressure in 
the accumulator and high pressure system falls to a level at which the 
pressure switch 134 will open. This pressure is below that at which the 
switch closes and, for example, may be 2100 p.s.i. When the pressure 
switch opens solenoid 136 is deenergized and valve 137 is returned to its 
"normal" condition where pressure in line 138 is relieved through the 
valve to the reservoir 116. When the pressure in line 138 is relieved, the 
check valve of the pilot operated check valve 126 is again seated and flow 
from accumulator 132 to the machine 10 is stopped. 
When the flow through the valve 126 to the machine 10 is stopped, the 
pressure at the back of the small piston 122 is reduced and the spring 121 
acts on piston 118 to move the control ring back to its centered position. 
If further booster power is needed and it is desired to continue operation 
of the machine 10 as a motor, to supplement the operation of motor 100 it 
is only necessary to push the accelerator until another switch 141 is 
closed. This switch is connected directly to the solenoid 136 and 
by-passes the pressure switch 134. When the switch 141 is closed the 
solenoid 136 is energized and valve 137 is operated, as previously 
described, to allow high pressure fluid into line 138, thereby moving the 
check valve 136 off its seat. All pressure in the accumulator 132 can thus 
be used to drive machine 10 as a motor, if desired. The pressure, will, of 
course, build-up in the accumulator chamber again during subsequent 
braking operations. 
The system herein described is especially suited for use with vehicles and 
particularly with electrically powered vehicles. However, it will be 
apparent that other prime movers could as well be used with but minor 
modification of the overall system. The system described provides for 
actuation of the machine 10 as a pump to store energy during braking, and 
as a motor to assist in propulsion during acceleration. Thereafter the 
prime mover can be used to maintain vehicle speed and accumulated energy 
can be provided to meet extraordinary demands such as may occur during 
passing, hill climbing or emergency conditions. 
When reverse motion of the vehicle is desired the switch 106 is moved to 
contact 150 and the controller 109 is operated to move switch 110 to 
complete a circuit through contact 110b for reverse operation of the 
motor. It is not contemplated in the present system that the machine 10 be 
used to assist in such reverse movement. 
While other controllers 109 may be satisfactory, an SCR controller, 
manufactured by the General Electric Company has been found suitable for 
selectively actuating the collector switch 110 in response to positioning 
of the switch 106 and movement of accelerator 108. 
The hydraulic system is protected from over pressurization by a pressure 
relief valve 151 that is connected to line 130 and that will open in the 
event of excess pressure in the system to discharge into the reservoir 
116. 
In the event of a line rupture or overspeeding of the vehicle wheels or 
drive shaft the excess flow valve 131 will close. The excess valve can be 
reset by pressurizing of the high pressure portion of the system as has 
been previously described. 
Although a preferred form of our invention has been herein disclosed, it is 
to be understood that the present disclosure is made by way of example and 
that variations are possible without departing from the scope of the 
hereinafter claimed subject matter, which subject matter we regard as our 
invention.