Abstract: A hydraulic power steering system has a vane type pump which is operable to supply fluid to a power steering gear at a volumetric rate determined in part by the system pressure or system demand. The flow from the pumping chambers is partially bypassed through a bypass passage formed between the cam ring and the pump thrust plate. The bypass passage is urged to the open position by a bypass spring which urges separation between the cam ring and the thrust plate. The pressure plate of the pump responds to system pressure or demand to urge the cam ring into abutment with the thrust plate thereby reducing the opening and decreasing the bypass flow.

Abstract: A rotary compressor formed with an unloading port maintaining a working space in communication with a suction chamber and opened and closed by a valve, to vary the capacity of the compressor. The internal pressure of the working space is sensed in a compression stroke or this pressure and the pressure of a fluid drawn by suction are both sensed, so as to open and close the valve based on the sensed internal pressure of the working space or the pressure differential between the internal pressure of the working space and the pressure of the fluid drawn by suction, to give suitable hysteresis to the operation characteristics of the on-off valve to stabilize the operation of the on-off valve.

Abstract: A pump includes a rotor, a cam encircling said rotor and means for effecting relative rotation of the cam and rotor about an axis. A plurality of vanes are carried by the rotor and engage the cam to define pumping pockets which expand and contract on rotation of the rotor. A check plate is movable along the rotational axis to communicate expanding and contracting pumping pockets. There is a cavity on one side of the cheek plate, and a fluid passage conducts fluid pressure into the cavity which fluid pressure biases the cheek plate into a position blocking the flow of fluid from the contracting pumping pockets to the expanding pumping pockets. The pump also includes a servo valve for venting the pressure in the cavity to thereby control the flow of fluid between the contracting and expanding pumping pockets. A fluid passage in the cheek plate receives flow from the contracting pockets. The passage has a portion directing flow from the contracting pumping pockets radially inwardly of the cheek plate.

Abstract: A pump includes a rotor, a cam encircling said rotor and means for effecting relative rotation of the cam and rotor about an axis. A plurality of vanes are carried by the rotor and engage the cam to define pumping pockets which expand and contract on rotation of the rotor. A cheek plate is movable along the rotational axis to communicate expanding and contracting pumping pockets. There is a cavity on one side of the cheek plate, and a fluid passage conducts fluid pressure into the cavity which fluid pressure biases the cheek plate into a position blocking the flow of fluid from the contracting pumping pockets to the expanding pumping pockets. The pump also includes a servo valve for venting the pressure in the cavity to thereby control the flow of fluid between the contracting and expanding pumping pockets. A fluid passage in the cheek plate receives flow from the contracting pockets. The passage has a portion directing flow from the contracting pumping pockets radially inwardly of the cheek plate.

Abstract: A pump has an inlet, an outlet, and a fluid displacement mechanism operable to pump fluid from the inlet to the outlet. A cheek plate in the pump is movable to control a flow of fluid from the outlet back to the inlet and thereby to vary the fluid flow to a hydraulic system supplied by the pump. Acting on different and unequal surface areas of the cheek plate are two fluid pressure forces. One fluid pressure force is provided by fluid pressure in a cheek plate control chamber. The force acts with a spring biasing force to bias the cheek plate into a position blocking the flow of fluid from the outlet back to the inlet. The second fluid pressure force acts on the cheek plate against the spring force and the first fluid pressure force. A first orifice communicates the pump outlet with the hydraulic system, a second orifice communicates the system with the control chamber, and a third orifice communicates the control chamber with the pump inlet.

Abstract: An electric fuel pump which is self-contained in a unitary housing with a fuel inlet at one end leading to a rotary eccentric pump, the pumped fuel passing out an outlet at the other end of the housing. A relief valve in the form of a shaped plate at the pump end by-passes fuel when there is reduced demand at the outlet. The outlet end of the pump is formed as a brush holder for the electric drive motor and a magnet retainer for the field assembly. A substantially constant pressure at the outlet with varying flow demands is the function of the relief valve.

Abstract: Flushable rotary gear pumps for delivering fluidic material, such as liquid coating material, may quickly and thoroughly be flushed of material of one type in preparation for delivering material of another type. In one embodiment, a valve selectively establishes a bypass channel between an inlet to and an outlet from a pump, thereby to accommodate a relatively large volume flow of flushing media through the pump and supply and delivery lines therefor. In another embodiment, the valve is structured to monitor fluid pressure developed by the pump and to automatically control and limit the pressure to a maximum value should an overpressure condition develop. In yet other embodiments passages are provided internally of the pump for conveying flushing media to all exposed surfaces of the gears, gear shafts and pump body to flush the same of coating material, whereby the entirety of the pump may readily be cleansed. If desired, the various features may be combined in a single pump.

Abstract: A movable section of a housing of a pump that permits an inlet port to be connected to an outlet port whenever a predetermined fluid pessure differential develops therebetween to reduce the work required to move a wall between the input port and the output port by an input member.

Abstract: A rolling piston compressor comprising: a casing of circular cross-section; a rolling piston supported within the casing on a drivable eccentric shaft so as to be freely rotatable thereon and adapted to roll on the internal surface of the casing in the course of rotation of the shaft; at least one separating slide slidably supported in the casing and resiliently urged by the action of a spring against the circumference of the rolling piston, said slide being disposed between an inlet port for drawing in a medium which is to be compressed and an outlet port for the delivery of the compressed medium, and being associated with a device for locking the separating slide in a position in which the free edge does not bear on the rolling piston circumference.

Abstract: A modulating system for a rotary hermetic compressor is provided with a valve operable by a force varying with the difference in pressure between the suction and discharge pressure for allowing a portion of the refrigerant gas being compressed to travel from the compression side of the roller to the suction side of the roller when the design peak load of the compressor is exceeded.

Abstract: An electric fuel pump which is self-contained in a unitary housing with a fuel inlet at one end leading to a rotary eccentric pump, the pumped fuel passing out an outlet at the other end of the housing. A relief valve in the form of a shaped plate at the pump end by-passes fuel when there is reduced demand at the outlet. The outlet end of the pump is formed as a brush holder for the electric drive motor and a magnet retainer for the field assembly. A self-aligning composite pump assembly is utilized with a motor housing. A substantially constant pressure at the outlet with varying outlet flow is the function of the relief valve.

Abstract: A movable section of a housing of a pump that permits an inlet port to be connected to an outlet port whenever a predetermined fluid pressure differential develops therebetween to reduce the work required to move a wall between the input port and the output port by an input member.

Abstract: Rotary displacement pump, of which the delivery pressure can be adjusted by modifying the losses in the gap between the lateral flank or flanks of one or more of the gear wheels and the house in which these gear wheels are enclosed, at the place of this gap also the mouth of a channel being present, which channel is or can be connected to a return line.

Abstract: A rotary positive-displacement pump in which the vane or vanes separating the chambers are locked in the inner dead center point after a certain outlet pressure has been attained, in order to shut off the pump. A corresponding locking apparatus has a detent which assures that each vane is locked in a form-locking manner in the position which shuts off the pumping action. Preferably, the locking apparatus has an overstroke step by means of which it is assured that each vane is constantly held at an increased distance from its sliding surface so that friction and impact noises are positively avoided.

Abstract: A rotary fluid pressure device such as a motor or pump of the type utilizing a Geroler.RTM. gear set. The internal teeth of the Geroler.RTM. are tubular members mounted on bearings to be slightly movable. Between each adjacent pair of tubular teeth is a check valve in the form of a roller which is mounted to be movable slightly more than are the tubular teeth. A resilient band surrounds the rollers, biasing each of them inwardly toward engagement with the adjacent teeth, but permitting each of the roller check valves to move out of sealing engagement with the adjacent teeth when the fluid pressure in the adjacent volume chamber exceeds the combined biasing force of the resilient band and the fluid in the outer fluid chamber. The invention provides a low cost Geroler.RTM. gear set permitting greater manufacturing tolerances, and having improved low speed characteristics and volumetric efficiency, resulting from minimized tooth-tip leakage.

Abstract: A positive fluid pump is provided which is capable of being cleaned in place by a circulating cleaning solution without the various pump components being disassembled. The impellers for the pump are rotatably mounted within a chamber formed in a housing. The inlet and the outlet for the chamber are separated from one another by the engaging impellers during normal operation of the pump. One of the side walls forming the pump chamber is provided with a cavity in which is slidably and sealingly mounted a wall piece. Under normal operation of the pump, the wall piece assumes a first position wherein one surface thereof is disposed adjacent the corresponding end faces of the impellers. When, the pump is being cleaned in place, the wall piece assumes a second position independently of the impellers wherein the one surface thereof is recessed from the pump chamber and the inlet and the outlet are interconnected permitting the cleaning solution to circulate through the chamber and around the impellers.

Abstract: A pump comprises a housing having an inlet and an outlet. The housing defines a pumping chamber and pumping means is located in the chamber and is operable to pump fluid from the inlet to the outlet. The pumping means includes pumping elements which define a series of pumping pockets which expand and contract to effect pumping of fluid. A cheek plate having one axial side adjacent to and facing the pumping means is supported in the housing. The cheek plate has a sealing position blocking fluid communication between the pumping pockets and is movable therefrom to enable fluid to flow directly between the pockets. The housing defines a cavity on the other axial side of the cheek plate. A fluid passage directs a flow of fluid from the pumping means into the cavity for urging said cheek plate into sealing position. A seal is provided between the cheek plate and the housing blocking flow into the cavity. An orifice is located in the pump outlet.

Abstract: A gear pump and motor having a plurality of pumps and motors, each of which have at least three gears interengaged with one another, seal members disposed adjacent to the gears, and control means for selectively controlling the movement of the seal members toward or away from the gears of the pump and motors so as to selectively actuate the pumps and motors so as to attain a desired output.

Abstract: An integral housing type rotary positive displacement fluid flow device such as a power steering pump is provided with a servo valve sensitive to a pressure gradient on opposite sides of an orifice in the fluid flow path, controlling the unloading of a fluid pressure loaded cheek plate which unseats to directly bypass fluid from the outlet to the inlet in amounts exceeding the flow control set point and has an efficiently cored housing providing cavities for the components and passages connecting them in operative relation.

Abstract: The pressure acting on a pressure loaded cheek plate in a pump is selectively vented by a servo valve actuated by the buildup of pressure in the pump outlet caused by normal parasitic losses in a downstream hydraulic flow circuit. Since it may be desirable to actuate the servo valve by the pressure drop across an orifice in the outlet line or by a suitable orifice in the pump return to pump, both embodiments are disclosed as exemplary means for achieving the premises of this design.