Abstract: A vane compressor has a vane back pressure adjustment device including back-pressure chambers defined in a vane-supporting rotor and surrounded by vanes and side blocks secured to axial ends of a cylinder. The back-pressure chamber has axial ends disposed to follow a path against each of the side blocks when the rotor rotates. The path is divided into at least one high-pressure zone in which the vanes move across a pump outlet defined in the cylinder, and at least one normal-pressure zone which is the remainder of the path. In the normal-pressure zone, oil grooves defined in surfaces of the side blocks which face the rotor and supplied with oil from an oil sump in the vane compressor are in communication with the back-pressure chambers, to thereby maintain the oil pressure in the back-pressure chambers at a pressure level in the oil sump.

Abstract: A cylinder has at least one valve seating surface-forming portion which has an outer surface formed therein with at least one recess, the bottom surface of which serves as a valve seating surface. A discharge valve is arranged on the valve seating surface-forming portion to close or open outlet holes each formed in corresponding ones of the valve seating surface. The discharge valve has at least one valve body formed of an elastic plate member disposed in close contact with a corresponding one of the valve seating surface. Preferably, the valve seating surface is arcuately concavely curved and the corresponding valve body has a correspondingly curved surface. The outlet holes are each formed in a thinnest portion of the valve seating surface-forming portion.

Abstract: A double acting type compressor has a main body which is formed by a cylinder block and a pair of cylinder heads secured to opposite ends of the cylinder block. The main body is formed therein with a pair of discharge chambers arranged at opposite ends thereof, a discharge passageway communicating the discharge chambers with each other, and a discharge port communicating substantially directly with the discharge passageway. A pulsation attenuating means formed of restriction hole means is provided between each of the discharge chambers and the discharge passageway. Compression medium in each of the discharge chambers flows into the discharge passageway through the restriction hole means of the pulsation attenuating means, while simultaneously having its pulsations attenuated, and then is supplied into an associated external circuit through the discharge port.

Abstract: A vane compressor has a vane back pressure adjustment device including back-pressure chambers defined in a vane-supporting rotor and surrounded by vanes and side blocks secured to axial ends of a cylinder. The back-pressure chamber has axial ends disposed to follow a path against each of the side blocks when the rotor rotates. The path is divided into at least one high-pressure zone in which the vanes move across a pump outlet defined in the cylinder, and at least one normal-pressure zone which is the remainder of the path. In the normal-pressure zone, oil grooves defined in surfaces of the side blocks which face the rotor and supplied with oil from an oil sump in the vane compressor are in communication with the back-pressure chambers, to thereby maintain the oil pressure in the back-pressure chambers at a pressure level in the oil sump.

Abstract: A vane compressor has a vane back pressure adjustment device including back-pressure chambers defined in a vane-supporting rotor and surrounded by vanes and side blocks secured to axial ends of a cylinder. The back-pressure chamber has axial ends disposed to follow a path against each of the side blocks when the rotor rotates. The path is divided into at least one high-pressure zone in which the vanes move across a pump outlet defined in the cylinder, and at least one normal-pressure zone which is the remainder of the path. In the normal-pressure zone, oil grooves defined in surfaces of the side blocks which face the rotor and supplied with oil from an oil sump in the vane compressor are in communication with the back-pressure chambers, to thereby maintain the oil pressure in the back-pressure chambers at a pressure level in the oil sump.

Abstract: A swash plate compressor is disclosed which is provided with a compression capacity control apparatus capable of returning an output pressure of a high pressure chamber of one cover to a low pressure chamber of the same cover. The control apparatus comprises a delivery chamber which is communicated with a high pressure chamber of the other cover, isolated from the high pressure chamber of the one cover and connected to a delivery conduit. The control apparatus also comprises a compression capacity control passageway providing communication between the delivery chamber and the low pressure and high pressure chambers of the one cover. A rotary three-way valve member is disposed in the control passageway to interrupt the communication between the delivery chamber and the high pressure chamber of the one cover while establishing communication between the low pressure and high pressure chambers of the one cover.

Abstract: A double acting type compressor has a main body which is formed by a cylinder block and a pair of cylinder heads secured to opposite ends of the cylinder block. The main body is formed therein with a pair of discharge chambers arranged at opposite ends thereof, a discharge passageway communicating the discharge chambers with each other, and a discharge port communicating substantially directly with the discharge passageway. A pulsation attenuating means formed of a multiplicity of small through holes is provided between each of the discharge chambers and the discharge passageway. Compression medium in each of the discharge chambers flows into the discharge passageway through the small through holes of the pulsation attenuating means, while simultaneously having its pulsations attenuated, and then is supplied into an associated external circuit through the discharge port.

Abstract: A pair of combined cylinder blocks which are horizontally disposed are formed with wall portions extending from the boss portions of the cylinder blocks to the bottoms thereof. The wall portions define therebetween a swash plate chamber and an oil pan located beneath the swash plate chamber. The wall portions are each formed with a lubricating oil channel communicating the oil pan with a through bore formed in the cylinder block through which the drive shaft of the compressor extends. Due to a pressure differential between the swash plate chamber and the suction chambers of the pump, lubricating oil in the oil pan is led through the lubricating oil channels and gaps between the drive shaft and the through bores and supplied to radial bearings supporting the drive shaft in the through bores, thrust bearings supporting the swash plate and the sliding portions between the swash plate and the pistons to lubricate same.

Abstract: Front and rear radial roller bearings are provided in front and rear side blocks of the pump housing. A partition wall member is secured to an end face of the rear side block remote from the rotor to define a sealing chamber therebetween. The sealing chamber communicates with a back pressure chamber in the rotor through the rear radial roller bearing. A shaft-seal chamber defined between the front head and the front side block communicates with the back pressure chamber through the front radial roller bearing. The pump housing is formed therein with passage means communicating the discharge pressure chamber with at least one of the sealing chamber and the shaft-seal chamber.

Abstract: A partition member is fitted within a casing at a location between an end wall of a pump housing accommodated within the casing and an opposed inner end face of the casing and cooperates with the one end wall to define a suction chamber therebetween. A first discharge pressure chamber is defined between an outer peripheral surface of the pump housing and an inner peripheral surface of the casing, and a second discharge pressure chamber between the above opposed inner end face of the casing and the partition member, respectively. The two discharge pressure chambers communicate with each other via passages formed through the partition member and the above end wall of the pump housing. A suction port and a discharge port are formed in the casing at the same axial side thereof, the former opening in the suction chamber in a substantially direct manner.

Abstract: In a vane compressor wherein at least two spaces are defined between a pump housing and a rotor disposed within the pump housing, for defining pump working chambers in cooperation with vanes carried in slits in the rotor, each of the vanes has an axial end edge provided with engaging means. Arresting means is disposed for engagement and disengagement with the engaging means of the vanes. When the arresting means is in a position engaging with the engaging means, it arrests each of the vanes in a retracted position in the vane slit in the rotor, while the vane is circumferentially moving in at least one of the pump working chamber-defining spaces from a pump inlet opening in the same space to a pump outlet opening in the same space.

Abstract: The communication between at least one of the pump inlets opening in at least two housing cavities and the suction chamber can be interrupted by a first valve means for prohibiting fluid compression in at least one of the housing cavities associated with the at least one pump inlet. At least one of the front and rear side blocks is formed with at least two passage means at locations corresponding to different ones of the cavities for introducing compressed fluid into back pressure chambers formed in the rotor. The communication between at least one of the passage means and the suction chamber can be interrupted by a second valve means.

Abstract: A swash plate compressor is disclosed which is provided with a compression capacity control apparatus capable of returning an output pressure of a high pressure chamber of one cover to a low pressure chamber of the same cover. The control apparatus comprises a delivery chamber which is communicated with a high pressure chamber of the other cover, isolated from the high pressure chamber of said one cover and connected to a delivery conduit. The control apparatus also comprises a compression capacity control passageway providing communication between the delivery chamber and the low pressure and high pressure chambers of said one cover. A valve member is disposed in the control passageway to interrupt the communication between the delivery chamber and the high pressure chamber of said one cover while establishing communication between the low pressure and high pressure chambers of said one cover.

Abstract: A sealing chamber is defined between the front head and the front side block, and an oil chamber between the rear side block and a partition member secured to the rear end face of the rear side block, respectively. The drive shaft, on which the rotor is rigidly fitted, is radially supported by a pair of roller bearings provided at the front and rear side blocks. The bearings have end portions remote from the rotor enclosedly disposed in the sealing chamber and the oil chamber. The lubricating oil feeding system includes lubricating oil feeding bores formed in the front and rear side blocks and communicating with a zone under discharge pressure, and clearances between the front and rear side blocks and opposed end faces of the rotor. The clearances have predetermined flow resistance, and communicate, on one hand, with the back pressure chamber formed within the rotor, and on the other hand, with the sealing chamber and the oil chamber by way of the above roller bearings.

Abstract: A vane compressor has a suction connector and a discharge connector arranged at a rear portion thereof. A rear suction chamber is formed at a rear side of the rear side block and communicates with pump working chambers. A passage means directly communicates the above rear suction chamber with an annular front suction chamber formed in the front head in a manner surrounding a sealing chamber accommodating a shaft-seal means.

Abstract: A sealing chamber is defined between the front head and the front side block. The drive shaft on which the rotor is rigidly fitted is journalled by front and rear plain bearings provided on the front and rear side blocks, respectively. The bearing on the front side has an end portion remote from the rotor enclosedly disposed in the sealing chamber. The sealing chamber communicates in a direct manner with the suction port formed in the compressor casing by way of a passage means so as to be supplied in a direct manner with suction refrigerant having a low temperature and a low pressure.

Abstract: The front and rear side blocks are each formed therein with a first lubricating oil passage which supplies high pressure lubricating oil, and at least one of the side blocks is formed therein with a second lubricating oil passage communicating with the back pressure chamber formed within the rotor. The first and second lubricating oil passages each open at one end in the sliding peripheral surface of a plane bearing formed with the corresponding side block. The drive shaft has its interior formed with a lubricating oil chamber and its peripheral wall formed with at least one lubricating oil feeding hole communicating with the lubricating oil chamber.

Abstract: An electromagnetic spring-wound clutch comprising a driving member, a driven member axially aligned with the driving member, a coil spring mounted around both the driving and driven members, a first clutch armature member interposed between the driving member and the coil spring and operatively connected to the coil spring, and at least one second clutch armature member rotatably interposed between the first clutch armature member and the driving member. When the clutch is actuated, the first, second clutch armature members and the driving member are brought into frictional engagement with each other, immediately after occurrence of slight slips between the second clutch armature member and the driving member and between adjacent ones of the first clutch armature member and the at least one second clutch armature member.

Abstract: In a vane compressor, a liner formed of iron or an alloy thereof is disposed along the endless camming inner peripheral surface of the cylinder forming part of the pump housing. The liner has at least one break extending thereacross and has its whole surface elastically permanently urging the cylinder in the radially outward directions. The use of the liner permits forming the rotor and the cylinder of aluminum or an alloy thereof. Preferably, the cylinder has its camming inner peripheral surface formed with a pair of elongate recesses extending parallel with the axis of the rotor and diametrically symmetrically arranged. The recesses are supplied with pumped compression fluid. The liner is partially urged by the rotor and located in the above recesses to maintain fluid tightness between the suction side and the discharge side in the pump housing.

Abstract: In a swash-plate type compressor, a partition wall, which separates a suction passageway extending through the cylinder block and the valve plates from the swash plate chamber, has its lateral wall formed with a refrigerant gas inlet opening which communicates the suction passageway with the swash plate chamber. The refrigerant inlet opening opens in the suction passageway with its opening end directed upstream in the refrigerant gas flow in the suction passageway. The partition wall has two opposite end wall portions, at least one of which is formed with a refrigerant gas outlet opening communicating the swash plate chamber with the suction passageway.