Abstract: A multi-stage vacuum pump comprising a stator defining multiple pumping chambers is discussed. The stator comprises a plurality of transfer channels for providing a fluid passage from an outlet port of one of the plurality of pumping chambers to an inlet port of a subsequent pumping chamber. Some of the transfer channels comprise two side channel sections on opposing sides of the stator. One of the transfer channels comprises a single side channel section on one side of the stator. The vacuum pump further comprises a gas ballast inlet channel arranged on an other side of the stator to the one side of the stator.

Abstract: In a rotary compressor of a vane rotary type, an outer peripheral surface of an eccentric portion of a shaft on a side adjacent to a center of the shaft is located radially inwardly of an outer peripheral surface of a main shaft inserted in a main bearing and that of an auxiliary shaft inserted in an auxiliary bearing. Also, a back clearance means used in mounting a piston on the shaft is provided in each of an inner peripheral surface of the piston and the eccentric portion of the shaft. Such configurations can reduce a diameter of the eccentric portion.

Abstract: An enclosed positive displacement mechanism including a body with an inlet and an outlet; a rotor mounted in the body and rotatable about a main axis; an orbiting piston located in the cavity, rotatable about an eccentric secondary axis and arranged to orbit around the main axis to roll on the internal side surface of the cavity; and a vane located in the cavity, slidable in the piston and mounted in the body between one inlet and one outlet so as to oscillate. The orbiting piston and the vane divide in cyclic manner the cavity into a first and a second chamber with variable volume, which are mutually complementary and communicate with the inlet and the outlet. During a portion of its oscillation, the vane passes through the piston and is in contact with the side surface of the cavity, thereby separating the chambers in a fluid-tight manner.

Abstract: A compressor includes a drive shaft, a housing, an annular rotor, and cradles. The rotor has cradle windows. The rotor can rotate within the rotor chamber together with the drive shaft while being in sliding contact with the housing at the circumferential surface. The cradles are provided in the cradle windows to be pivotable about pivot axes. When pivoting, the cradles maintain the compression chambers in an airtight state by being in contact with the housing at pivoting ends of the cradles, the pivoting ends extending along the direction parallel to the axis. The rotor chamber includes an outer operation chamber located on the outside of the rotor, and an inner operation chamber located on the inside of the rotor. The cradles, and the outer operation chamber and/or the inner operation chamber form the compression chambers, the volumes of which are varied by the rotation of the rotor.

Abstract: An airtight compressor includes a compression mechanism disposed inside an airtight container in a position below a gas retention space. An oil supply passage supplies oil from an oil reservoir both to the gas retention space (14) and to a sliding portion of the compression mechanism in a compression space. The oil supply passage communicates the gas retention space with a second space located on an opposite side of the piston from the intake chamber. A second channel is a channel that is different from the oil supply passage. The second channel enables a gas medium to flow from the gas retention space to the second space. Preferably, passage resistance when the gas medium flows through the second channel is less than when the gas medium flows through the oil supply passage.

Abstract: A rotary compressor includes a cylinder body, end plate members fitted on both sides of the cylinder body, a roller placed in a cylinder chamber, a blade fitted to the roller, and a bushing for supporting the blade. A width of the bushing in a roller axis direction is larger than an axial width of the roller. A gap in the roller axis direction between the roller and the end plate members is larger than a gap in the roller axis direction between the bushing and the end plate members.

Abstract: A motor (20) is driven by pressure medium delivered from an external pressure source. A rotor part (28) forms sealing abutment against a local area (2Id) of the motor's (20) cylindrical inner wall (21c). A piston-forming plate part (30) is pivot-mounted at one end to the rotor part (28) and can be pivoted forwards and backwards in the motor casing's working chamber (21) relative to the rotor part (28). At the same time at its opposite end the piston-forming plate part (30) forms sealing abutment along the motor casing's (26) circular inner wall (21c).

Abstract: A compressor assembly having a drive shaft supported by a main bearing and an outboard bearing located on opposite axial ends of a cylinder block. The main bearing has a bearing support formed therein in which first and second apertures are defined. The diameter of the first aperture is less than the diameter of the second aperture. The shaft extends through the first and second apertures with the diameter of the drive shaft having an outer diameter which is no greater than the diameter of the first aperture. A sleeve is mounted on the drive shaft and is at least partially disposed within the second aperture. A bearing is located in the second aperture and engages the sleeve and the main bearing to rotationally support the drive shaft. The sleeve can have a thickness which allows the bearing to be of a standard size rather than a custom size.

Abstract: A rotary compressor has a cylinder, a crank shaft having an eccentric part disposed in said cylinder, a bearing which rotatably supports said crank shaft, a roller which moves in said cylinder following said eccentric part, and a vane whose all or part of the tip is of R configuration, wherein a groove with which the vane tip is disposed in contact is provided on the outer periphery of said roller, a first oil groove is provided on the end face of said roller, and said roller is provided with an oil hole communicating said first oil groove and said groove of the roller.

Abstract: A rotary compressor of the low operational noise type is disclosed. This compressor consists of a casing, a rotating shaft set within the casing, a roller eccentrically fixed to the rotating shaft and eccentrically, rotatably set within a cylinder so as to form a variable suction chamber and a variable compression chamber within the cylinder. The compressor also has a bypass passage, which is formed on the internal surface of the cylinder at a position around the refrigerant exhaust stroke initiating point, thus allowing the compression and exhaust chambers to communicate with each other through the bypass passage and allowing highly compressed refrigerant to be fed from the compression chamber back into the suction chamber at the initial stage of each exhaust stroke.

Abstract: A rotary compressor is provided with a cylinder which defines a cylinder chamber and a piston disposed in the cylinder chamber. The piston includes a roller which performs a revolving motion within the cylinder chamber and a vane which partitions the interior of the cylinder chamber into a suction chamber and a compression chamber. A small space is provided so as to communicate with the compression chamber in only a predetermined section without communicating with the suction chamber so as to suppress noise generated by a pressure fluctuation in the interior of a compression chamber and, at the same time, can prevent the occurrence of a loss induced by re-expansion of a refrigerant remaining in a small space and a loss induced by return of the refrigerant to a suction chamber.

Abstract: A rotary compressor has a cylinder, a crank shaft having an eccentric part disposed in said cylinder, a bearing which rotatably supports said crank shaft, a roller which moves in said cylinder following said eccentric part, and a vane whose all or part of the tip is of circular configuration, wherein a groove with which the vane tip is disposed in contact is provided on the outer periphery of said roller, a first oil groove is provided on the end face of said roller, and said roller is provided with an oil hole communicating said first oil groove and said groove of the roller.

Abstract: A slit, spanning a distance across the top of the vane slot in a cylinder for a rolling piston compressor, safely distributes the stress which occurs in the vane slot. The slit opens onto the bore, in the cylinder, which is provided for a rotary shaft and rotary piston, and onto the vane slot.

Abstract: A notch is provided in the motor end bearing of a rotary compressor in the region of the discharge port. The notch enhances the flow by smoothing the flow path and guiding the flow so as to impinge upon the discharge valve in a glancing manner and reduces the noise from the valve and valve stop and from the turbulent flow through the discharge port. The notch is located along the axis of the discharge valve and on the side of the valve port on which the valve is pivoted.

Abstract: A rotary compressor having a cylinder within which an eccentric piston is rotated. A vane has one end mounted in a radial slot in the cylinder and an insert is mounted in the other end of the vane. The insert has a concave face to contact the outer surface of the piston as it rotates and an engaging element in the form of a key lodged in slots in the insert and the piston, acts simultaneously on the piston and insert and restrains the piston from rotating.

Abstract: A rolling piston type expansion machine eliminates the need for an open-close valve mechanism and smoothens the timing of inflow of high-pressure gas. The machine includes a cylinder having a discharge port and a roller freely gyratable or orbital in the cylinder. A freely movable blade supported in the cylinder has its tip in contact with the circumferential surface of the roller to form an expansion chamber. A gas passage is freely rotatably supported by a main bearing member and a secondary bearing member. The gas passage is formed in a main shaft having a crank shaft portion that gyrates or orbits the roller. An inlet port is provided along a shaft center of the main shaft. An inflow timing control portion controls inflow timing of the suction gas toward the expansion chamber via the inlet port of the gas passage.

Abstract: An oscillatory fluid pump is provided with a horizontally disposed cylindrical chamber disposed above and in communication with a rectilinear chamber along the entire length of both chambers. An inverted Y-shaped elastic member is secured at the lower ends of the downwardly angularly related legs to the bottom of the rectilinear chamber and the upstanding leg is secured to a cylindrical pumping member located in the cylindrical chamber. A cylindrical bore is eccentrically located along the length of the cylindrical pumping member of a drive shaft having an eccentric thereon extends through the bore and is supported at opposite ends by the housing.

Abstract: A rotary mechanical vacuum pump has a pump chamber formed of aluminum which has been treated by hard anodizing the working surfaces of the pump chamber and the lapped mating surfaces between the parts surrounding the chamber, with a high vacuum grease applied to such mating surfaces and providing an effective seal against leakage between the pump chamber and the ambient atmosphere.