Variable displacement compressor

A variable displacement compressor comprising:

• a housing having a suction chamber and a discharge chamber;
• a crank chamber defined in the housing;
• a drive shaft having a front end and a rear end, the shaft being supported in the housing so that the front end protrudes from the housing;
• a cylinder block forming part of the housing, wherein cylinder bores are defined in the cylinder block;
• a valve plate assembly, which includes a suction port, a suction valve, a discharge port and a discharge valve for each cylinder bore;
• single-headed pistons housed in the cylinder bores, respectively;
• a drive plate, which is housed in the crank chamber and is connected to the pistons to convert rotation of the drive shaft into reciprocating motion of the pistons, wherein the drive plate rotates integrally with the drive shaft;
• a control mechanism, which controls inclination of the drive plate by controlling the pressure of the crank chamber to change the volume of a refrigerant discharged from each cylinder bore into the discharge chamber;
• a radial bearing supporting the rear end of the drive shaft, wherein the refrigerant flows through the radial bearing;
• a holding bore, in which the rear end of the drive shaft and the radial bearing are located, wherein the holding bore is connected to a holding space, and the holding space is defined by the valve plate assembly, wherein the holding space is connected to the suction chamber;
• means for restricting being located in the holding space, and divide the holding space into a first region and a second region, wherein a clearance is formed between the drive shaft and the restricting means or between the restricting means and the valve plate assembly in a normal compressing operation, wherein the restricting means restricts the movement of the drive shaft, which movement would be equal to or greater than the clearance if there were no restriction of the movement, and the clearance disappears when the pressure of the crank chamber is increased rapidly by the control mechanism;
• and
• a passage connecting the first region to the second region.

A variable displacement compressor comprising;

• a housing having a suction chamber and a discharge chamber;
• a crank chamber defined in the housing;
• a drive shaft having a front end and a rear end, the shaft being supported in the housing so that the front end protrudes from the housing;
• a cylinder block forming part of the housing, wherein cylinder bores are defined in the cylinder block;
• a valve plate assembly, which includes a suction port, a suction valve, a discharge port and a discharge valve for each cylinder bore;
• single-headed pistons housed in the cylinder bores, respectively;
• a drive plate, which is housed in the crank chamber and is connected to the pistons to convert rotation of the drive shaft into reciprocating motion of the pistons, wherein the drive plate rotates integrally with the drive shaft;
• a control mechanism, which controls inclination of the drive plate by controlling the pressure of the crank chamber to change the volume of a refrigerant discharged from each cylinder bore into the discharge chamber;
• a radial bearing supporting the rear end of the drive shaft, wherein the refrigerant flows through the radial bearing;
• a holding bore, in which the rear end of the drive shaft and the radial bearing are located, wherein the holding bore is connected to a holding space, and the holding space is defined by the valve plate assembly;
• a passage connecting the holding space and the suction chamber;
• and
• a cylindrical body located in the holding space, wherein one end of the cylindrical body is fixed to the drive shaft, and the other end of the cylindrical body abuts against the valve plate assembly, wherein the cylindrical body divides the holding space into a first region and a second region, wherein the cylindrical body has a hole to connect the first region to the second region, wherein a clearance is formed between the drive shaft and the cylindrical body or between the cylindrical body and the valve plate assembly in a normal compressing operation, wherein the cylindrical body restricts the movement of the drive shaft, which movement would be equal to or greater than the clearance if there were no restriction of the movement, and the clearance disappears when the pressure of the crank chamber is increased rapidly by the control mechanism.