Abstract: An axial piston pump assembly includes a housing having first and second interconnected housing portions (12,14). A cylinder barrel (18) has an axis of rotation and is rotatably supported in the housing about the axis of rotation. The cylinder barrel (18) includes a plurality of pistons (22). The pistons (22) are reciprocally supported in the each of the piston cavities (20) for reciprocating movement parallel to the axis of rotation reacting with a cam surface (30) and causing the reciprocating movement of the pistons (22). The pistons (22) include a body portion (44) having a longitudinally extending central bore (46). One end of the bore (46) defines a fluid inlet (48) into the bore (46) and the other end defines a fluid outlet (51). The fluid inlet (48) includes a ball seat (50) and a ball member (52) seated therein and substantially over the fluid inlet (48), the ball member (52) engaging the cam surface (30).

Abstract: A swash plate type compressor having shoes provided with center holes on the slidable surfaces. The center hole provided with a bottom acts as a reservoir for lubricating oil and supplys the oil on the slidable surface of the shoe, which slides against the swash plate. There can be a second ring groove concentric to the center hole, or annexed grooves which are stretching outward radially from the center hole. The center hole also prevents the center part from protruding outward by thermal expansion, which is caused by friction. The slidable surface of the shoe is preferably coated with a layer containing solid lubricant so as to smooth the sliding motions.

Abstract: The apparatus for conveying and compressing a gaseous medium utilizes thermoacoustic oscillations. The oscillations are generated in a tubular cavity by means of a heat source or heat sink with the medium to be conveyed being taken in through a check valve on one side while being exhausted after compression through a second check valve on an opposite side. During operation, the heat is supplied to the medium within the tubular cavity to generate thermoacoustic oscillations.In one embodiment, a plurality of tubes can be disposed in series relative to a common line. Also, the apparatus can be used in combination with a helium liquifying plant.

Abstract: A power control device for an adjustable hydrostatic pump with a lever controlling a control valve piston and a pressure measuring piston loaded with feed pressure acting on said lever to control the pressure feed to a servo piston is provided wherein the pressure measuring piston loaded with feed pressure is mounted in a structural member slidable with the servo piston and slides lengthwise of the lever and the control valve piston is biased by resilient member toward the pressure measuring piston.

Abstract: The cryogenic pump operates in two stages, utilizing a supercharging part and a high pressure part. These two parts are comprised of a high pressure piston pump (3, 4, 34, 35) and a supercharger (5, 6, 61, 62) disposed in a tandem relationship and sharing a common piston rod (8). The supercharger is enclosed in a heat insulated intermediate container (7) and delivers the liquid cryogenic fluid to the high pressure cylinder. The pump operates to convey a liquid cryogenic fluid such as liquid nitrogen, for example, at a high pressure through evaporating means into pressure resistant commercial steel cylinders where the gaseous nitrogen is kept at a pressure of 200 bar and ambient temperature.

Abstract: A fluid operated pump displacement control system is provided wherein a self pressure is defined as a first control signal, and characterized in that an arbitrary switchable second control signal different from the first control signal is added to the first control signal, and a displacement is adapted to be switched to a displacement corresponding to a value of the second control signal as added to the first control signal. Further, a fluid operated pump displacement control system is provided comprising a control circuit connected to respective displacement control devices of variable displacement pumps and adapted to be operated by discharge pressure fluid from a discrete control pump.

Abstract: A water ring vacuum pump having a body with end members, an impeller in the body and having a shaft which extends through the end members and being journalled for rotation therein. One end member has an inlet and the other an outlet. A port plate is located in each member and adjacent the ends of the blades of the impeller whereby a manifold is formed between each port plate and its adjacent end chamber. The port plates are moveable relative to their adjacent end members by screws or the like passing through the end member, which screws abut the face of the port plate and can act to vary its location relative to the impeller and locking bolts passing through the end member and into threads in the port plate whereby the port plate can be moved away from the impeller. The locking bolts, when the impeller is correctly positioned, acts against the screws or the like which abut the port plate, thus serving to lock the port plate in position.

Abstract: A lubricant chamber encloses the sliding contact portions of a slant plate and the plurality of shoes to confine lubricating oil therein. The lubricating oil is permitted to leak from the chamber at a rate greater than the rate of flow of oil from the pressure pockets formed on the sliding faces of the shoes.

Abstract: In radial piston pumps and motors the dimensions of the rotor, pistons and piston shoes are optimized for best efficiency and power in a given size and weight. The efficiency and reliability of the piston shoes is improved by the provision of fluid pressure pockets in the outer face of the piston shoe which have cross-sectional areas exceeding the cross-sectional area of the piston whereon the piston shoe is pivotably borne. Welding of the outer face of the piston shoe is prevented and the devices are able to operate with higher pressures and rotary velocities.

Abstract: A hydraulic radial piston pump or motor comprises a rotary cylinder unit (20) mounted to rotate on a fixed pintle (25), the unit (20) having radial cylinder bores formed by cylinder sleeves (23) each housing a piston (40) connected by a ball joint (44) to a slipper (45) engaging a surrounding annular track ring (47). The unit (20) also includes a separately formed central sleeve (21) having ports (26) cooperating with ports (31,32) in the pintle, the pintle ports (31,32) and the sleeve ports (26) being elongated in a circumferential direction. The pintle has three parallel flow passages, two (28') of smaller diameter than the third (27'). The slippers (45) are held resiliently against the track ring (47) by a band (66) having windows (68) which fit the slippers, the band being of resilient material and split at one point. The cylinder unit (20) has a rounded external surface and is free to float in an axial direction which provides a self-centering effect.

Abstract: A method and apparatus for detecting standing heat in cattle includes an electronic timer module connected to a membrane switch. The module includes a digital time readout display, as well as audible and visible indicators. A saddle-like sleeve includes a transparent pocket having a sealable opening adapted to receive the timer module and membrane switch therein. The sleeve is adapted to be adhered to the base of the tail of a cow. The membrane switch is adapted to be actuated by the weight of other cows attempting to mount the cow when in heat. The switch actuates the timer, and also actuates intermittent operation of the audible and visible indicators to warn the cattle owner that the cow is in heat, and also to indicate exactly when the cow came into heat.

Abstract: An infinitely variable transmission, method of controlling an infinitely variable transmission, and an apparatus utilizing the method. The infinitely variable transmission provides a lever or walking beam having a variable fulcrum point. Power is supplied to one end of the lever, for example by cams on a driving shaft. Power is taken from the other end of the lever by use of a rack cooperating with a gear mounted to a one-way clutch on a driven shaft. The method controlling the infinitely variable transmission includes measuring the intake manifold pressure of the internal combustion engine driving the transmission and displacing the fulcrum point of the lever in response to the measurement obtained to vary the transmission ratio.

Abstract: A pump is positioned in the oil producing zone of a well to pump fluid therefrom and is driven by an oil accumulating chain used to recover oil from the well in conjunction with associated secondary drive means.

Abstract: A hydraulic fluid seal, a pressure plate and gear pump are provided in which two spaced adjacent surfaces are sealed, one surface having a groove opening toward the other surface, a sealing member adapted to fit in said groove and a plastically deformable interference member in the sealing member having a section such that it will plastically deform before the seal surface of the sealing member.

Abstract: A power drive unit and control system therefor avoiding performance degradation which can occur in control of the variable displacement hydraulic motor of the power drive unit by measurement of the angle of a displacement-setting wobbler of the motor and the speed of the motor. This is avoided by sensing flow through the motor which provides an indirect measure of wobbler position and speed of motor operation. The power drive unit and control system therefor has a variable displacement hydraulic motor with a displacement-setting wobbler positioned by pressure applied to a servo piston by an electro-hydraulic servo valve. The control system responds to a speed command having a value dependent upon a position loop which determines the relation between the actual position of a load and a commanded position, with the control providing for a maximum possible speed of motor operation under a particular load condition with a substantially constant rate of fluid flow through the motor.

Abstract: In a liquid ring compressor, the erosion and cavitation damage occurring under certain operating conditions is avoided by adding air or gas from the outside, at a pressure which approximately corresponds to the compression pressure, into particular pressure slot areas.

Abstract: A pump for applying pre-mixed cement, and similar mud-like flowable materials, employs power driven oppositely reciprocating pistons sliding in a pair of cylinders for pumping action. A control manifold, having a single cement discharge outlet, interconnects combined suction and discharge outlets of each pump cylinder with a cement supply hopper manifold inlet. Two manifold pump response chambers, and a single discharge chamber in flow communication with one another within the manifold, together with associated valving within each chamber, provides for unidirectional flow of cement under pressure from the manifold discharge outlet solely in response to the movement of the pistons within the pump cylinders. The pump response chamber valves have adjustable valve openings so that the pump may be employed with flowable materials of varying viscosity.

Abstract: A variable displacement fluid pump comprises a rotor rotatably disposed within a housing, an eccentric ring movable close to and apart from the rotor to change a first eccentricity between a center of an inner periphery of the eccentric ring and a fixed center of rotation of the rotor so as to vary a displacement of the pump, and a plurality of pumping chambers each having a variable volume which changes sequentially to introduce thereinto fluid from an inlet port and to discharge therefrom fluid to a discharge port as the motor rotates. The rotor is so disposed that the fixed center of rotation of the rotor is spaced apart by a predetermined second eccentricity from a locus of the center of the inner periphery of the eccentric ring towards the discharge port.

Abstract: An external combustion engine wherein a plurality of radially disposed piston cylinders are arranged around the axis of an output drive shaft. Pistons are reciprocal in the cylinders and actuate rollers carried by radially extending slide bearings, the rollers engaging in an eccentric cam groove formed in a flywheel fixed to the drive shaft. The cylinders have closed inner and outer ends and are provided with valve means for applying pressurized gas to opposite ends of the pistons at different times in a manner to provide power to a majority of the pistons at all times during rotation of the drive shaft. The engine can alternatively operate as a pump by applying motive power to the shaft.

Abstract: A reciprocating piston type refrigerant compressor includes a compressor housing having a cylinder block provided with a plurality of cylinders and crank chamber adjacent the cylinder block. A piston slides within each of cylinders and is reciprocated by a wobble plate driven by a cam rotor mounted on a drive shaft. The cam rotor comprises a rotor plate fixed on an inner terminal end of a drive shaft and slant plate with a sloping surface in close proximity to the wobble plate. The slant plate is hinged to the rotor plate for adjusting the slant angle thereof in response to change of pressure in the crank chamber. The pressure in the crank chamber is controlled by controlling communication between the crank chamber and the suction chamber. The wobble plate is supported for a nutational motion on a ball element which is disposed on supporting element slidably carried in the cylinder block to maintain the wobbling center thereof on the center of the ball element.