Scroll compressor

Abstract

A scroll compressor comprises a fixed scroll, an orbiting scroll engaged with the fixed scroll to form a compression chamber therebetween, a back pressure chamber arranged at a back side of an end plate of the orbiting scroll, a back pressure hole formed in the end plate of the orbiting scroll to form a fluidal communication between the compression chamber and the back pressure chamber, and a release valve mechanism for discharging the fluid from the compression chamber to the discharge space when a pressure in the compression chamber is higher than the pressure in the discharge space, wherein the back pressure hole and the release flow path are arranged to prevent both of the fluidal communication and the another fluidal communication from being formed simultaneously.

1 . A scroll compressor, comprising
 a fixed scroll including a base plate and a spiral wrap projecting from the base plate,   an orbiting scroll including an end plate and another spiral wrap projecting from the end plate and engaged with the fixed scroll to form a compression chamber therebetween,   a discharge space for receiving a compressed fluid from the compression chamber,   a back pressure chamber arranged at a back side of at least one of the fixed scroll and the orbiting scroll to press the fixed scroll and the orbiting scroll against each other,   a back pressure hole formed in at least one of the base plate and the end plate to enable a fluidal communication to be formed between the compression chamber and the back pressure chamber so that a pressure in the back pressure chamber is kept between an intake pressure and a pressure in the discharge space, and   a release valve mechanism including a release flow path to enable another fluidal communication to be formed between the compression chamber and the discharge space, and a valve arranged between the release flow path and the discharge space to open the release flow path to enable the fluid to be discharged from the compression chamber to the discharge space when a pressure in the compression chamber is higher than the pressure in the discharge space, so that an excessive compression in the compression chamber is prevented,   wherein the back pressure hole and the release flow path are arranged to prevent both of the fluidal communication and the another fluidal communication from being formed simultaneously during each orbital revolution.   
   
   
       2 . The scroll compressor according to  claim 1 , wherein the fluidal communication between the compression chamber and the back pressure chamber is formed intermittently by the back pressure hole. 
   
   
       3 . The scroll compressor according to  claim 2 , wherein the back pressure hole is formed in the end plate of the orbiting scroll, an end of the back pressure hole is arranged to be intermittently opened in accordance with the orbital motion of the orbiting scroll to a notch portion formed on a surface of the end plate of the fixed scroll at its radially outer side to fluidly communicate with the back pressure chamber, and the other end of the back pressure hole is arranged to fluidly communicate with the compression chamber before the fluid is discharged from the compression chamber to the discharge space. 
   
   
       4 . The scroll compressor according to  claim 1 , wherein the release valve mechanism is of a flapper valve type arranged on the base plate of the fixed scroll, and the valve has a valve body, an elastic member for urging the valve body toward the release flow path, a stopper for holding the elastic member, and a retainer for restraining a movable range of the stopper. 
   
   
       5 . The scroll compressor according to  claim 4 , wherein the release flow path has a cross-sectional shape of elongated hole, and a tapered shape at a side of the valve body to increase its cross-sectional area in a direction from the compression chamber toward the discharge space, and the valve body has a flat plate. 
   
   
       6 . A scroll compressor comprising a fixed scroll, an orbiting scroll engaged with the fixed scroll to form a compression chamber therebetween and capable of orbiting, a discharge space for receiving a compressed fluid from the compression chamber, a back pressure chamber arranged at a back side of an end plate of the orbiting scroll to press the orbiting scroll against the fixed scroll, a back pressure hole formed in the end plate of the orbiting scroll to enable a fluidal communication to be formed between the compression chamber and the back pressure chamber, and a release valve mechanism including a release flow path in a base plate of the fixed scroll to enable another fluidal communication to be formed between the compression chamber and the discharge space, and a valve arranged between the release flow path and the discharge space to open the release flow path to enable the fluid to be discharged from the compression chamber to the discharge space when a pressure in the compression chamber is higher than the pressure in the discharge space, so that an excessive compression in the compression chamber is prevented, wherein the back pressure hole and the release flow path are arranged to prevent both of the fluidal communication and the another fluidal communication from being formed simultaneously during each orbital revolution. 
   
   
       7 . A scroll compressor comprising a fixed scroll, an orbiting scroll engaged with the fixed scroll to form a compression chamber therebetween, a discharge space for receiving a compressed fluid from the compression chamber, a back pressure chamber arranged at a back side of an end plate of the orbiting scroll, a back pressure hole formed in the end plate of the orbiting scroll to enable a fluidal communication to be formed between the compression chamber and the back pressure chamber, and a release valve mechanism including a release flow path in a base plate of the fixed scroll to enable another fluidal communication to be formed between the compression chamber and the discharge space so that the fluid is discharged from the compression chamber to the discharge space when a pressure in the compression chamber is higher than the pressure in the discharge space, wherein the back pressure hole and the release flow path are arranged to prevent both of the fluidal communication and the another fluidal communication from being formed simultaneously during an orbital motion of the orbiting scroll.