Abstract: A self priming gear pump 14 for pumping liquids containing gases is provided with a vent pipe 26 for releasing entrapped gases that would otherwise collect at the outlet side of the pump 14. The vent pipe 26 terminates within the pump housing 21 at a zone which is out of the path of the oil centrifuged by the gears 25 and in the region lying near the point of intersection of the gears 25. An additional inlet pipe 27 which directs liquid across the main inlet into the gap between the periphery of one of the gears 25 and the housing 21 may be provided to improve liquid sealing.

Abstract: A rotary vane-type engine includes a rotor, a cam ring surrounding the rotor, and working vanes slidably disposed in radial slots of the rotor and engaging with one of their ends the inner contour of the cam ring. The vanes subdivide the space formed between the rotor and the cam ring into working spaces which are limited axially by side plates. Control ports provided in the side plates have throttle channels which extend in the rotor circumferential direction and connect the working spaces arranged on either side of the throttle channel with each other.

Abstract: In a gas pressure increasing system for increasing the pressure of a refrigerant gas or air having a scroll compressor, a condenser, a pressure reducing means and an evaporator or a scroll compressor and a gas cooler, an exhaust gas released from the scroll compressor after having its pressure increased by the scroll compressor itself is cooled and expanded to reduce its pressure to an intermediate pressure level to produce a gas of an intermediate pressure having a cooling capability. The gas of the intermediate pressure is used to provide a force for axially sealing an orbiting scroll member of the scroll compressor as well as to cool the scroll compressor and a motor.

Abstract: A three-lobe Root's blower is provided with feed back structure to bring the gas trapped in the impeller well volumes up to the discharge pressure prior to delivery. An essentially uniform and pulse-free discharge is produced by having a constant feed back flow rate which is achieved by always having a trapped impeller well volume in communication with the outlet via feed back structure which is sized to yield a continuous feed back flow rate.

Abstract: A compact, rotary gas-operated motor having only three moving components including valving. Pressurized gas entering through a crank causes it to move within a slot in an elongate rotor which rotates end-over-end within a generally triangular chamber. Pressurized gas bypassed to the space between the rotor and a chamber wall also causes rotation. Expansion ratios of 5:1 to 15:1 or more may readily be obtained.

Abstract: A gear pump or motor in which a pair of meshing gears are rotatably mounted in a housing and in which a throttle passage provides communication between a region of the housing in which, during rotation of the gears, high pressure is maintained and the region of the interstices between engaging teeth of the gears at which these interstices increase during such rotation, to prevent cavitation and to essentially reduce noise during operation.

Abstract: A variable capacity rotary screw compressor for a refrigeration system which includes a high pressure condenser, a subcooler, a main evaporator and an intermediate evaporator, the compressor including a primary inlet connected to receive low pressure vapor from the main evaporator, a secondary or intermediate inlet connected to receive high pressure vapor from the subcooler and/or intermediate evaporator, and a high pressure discharge port connected to the condenser, the compressor including a pair of oppositely rotating constant mesh helical lobe rotors and a slide valve to vary the capacity of the compressor by changing the points of admission of the low pressure vapor and the high pressure vapor to the rotors of the compressor, the points of admission of low pressure vapor and high pressure vapor being maintained in a fixed relation as the capacity of the compressor is varied.

Abstract: A rotary compressor having mating rotary impellers defined by lobes and well spaces therebetween, a discharge port sealed by the peripheral surface of one of the lobes and passages for communicating one impeller well space with a well space of the other impeller as the discharge port is sealed by the one impeller peripheral surface. According to one form, the passages are defined by conduits in the compressor housing; whereas according to a second form the passages are defined by a recess in one impeller and the interior of the compressor housing.