Swash plate type variable displacement compressor

Abstract

A housing has a peripheral wall that surrounds a crank chamber. The peripheral wall has a valve chamber that is recessed radially inward from an outer surface of the peripheral wall with respect to the axis. A bimetal member, which deforms in correspondence with the temperature in the crank chamber, is arranged in the valve chamber. A valve body, which is supported by the bimetal member, is arranged in the valve chamber. The peripheral wall has a first oil discharge passage and allows communication between the crank chamber and the valve chamber, and a second oil discharge passage through which the valve chamber and a suction chamber communicate with each other. When the temperature in the crank chamber exceeds a predetermined value and deforms the bimetal member to move the valve body, communication between the first and second oil discharge passage is permitted through the valve chamber.

1 . A swash plate type variable displacement compressor, comprising:
 a housing having a cylinder bore, a suction chamber, a discharge chamber, and a crank chamber;   a drive shaft, which is rotatably supported by the housing and exposed in the crank chamber;   a swash plate supported by the drive shaft in the crank chamber such that the inclination angle of the swash plate is changeable;   a piston received in the cylinder bore in a manner reciprocally movable;   a movement conversion mechanism arranged between the swash plate and the piston to convert swinging of the swash plate to reciprocation of the piston; and   a displacement control mechanism for adjusting displacement using pressure in the crank chamber, wherein   the housing includes a peripheral wall that surrounds the crank chamber in a circumferential direction with respect to the axis of the drive shaft and has an outer surface and an inner surface,   the peripheral wall includes a valve chamber recessed radially inward from the outer surface of the peripheral wall, a first oil discharge passage that has an opening in the inner surface of the peripheral wall and allows communication between the crank chamber and the valve chamber, and a second oil discharge passage that allows communication between the valve chamber and the suction chamber, wherein a temperature sensitive member, which deforms in correspondence with the temperature in the crank chamber, is arranged in the valve chamber, and a valve body supported by the temperature sensitive member is located in the valve chamber, and   when the temperature in the crank chamber exceeds a predetermined value to deform the temperature sensitive member and move the valve body, communication between the first oil discharge passage and the second oil discharge passage is permitted through the valve chamber.   
     
     
         2 . The compressor according to  claim 1 , wherein the inner surface has a cylindrical surface extending parallel to the axis, the first oil discharge passage having the opening in the cylindrical surface. 
     
     
         3 . The compressor according to  claim 1 , wherein the valve body has a surface facing the first oil discharge passage, and a recess is formed in the surface. 
     
     
         4 . The compressor according to  claim 1 , wherein the second oil discharge passage is a bolt hole, through which a bolt for fastening the housing is passed. 
     
     
         5 . The compressor according to  claim 1 , further including an urging member arranged in the valve chamber, wherein the urging member urges the valve body in a direction opposite to the direction in which the valve body moves when the temperature in the crank chamber exceeds the predetermined value. 
     
     
         6 . The compressor according to  claim 1 , wherein a bulging portion that bulges radially outward is formed in the peripheral wall, and the valve chamber is formed in the bulging portion. 
     
     
         7 . The compressor according to  claim 1 , wherein the displacement control mechanism has a centrifugal oil discharge valve mechanism, which sends lubricant oil from the crank chamber to the suction chamber when the drive shaft rotates at a speed greater than a predetermined speed.