Refrigerant compressors

In a refrigerant compressor unit of the type having a compressor housing, a cylinder block mounted within said compressor housing having a plurality of cylinders, a plurality of piston means slidably disposed within said plurality of cylinders, means for driving said piston means within said cylinders to compress refrigerant gas, said compressor housing having a first chamber adjacent said cylinder block for containing said driving means, a cylinder head having a suction chamber and a discharge chamber which operatively communicate with said cylinders, and a gas passageway communicating between said first chamber and said suction chamber to return blow-by gas in said first chamber to said suction chamber, the improvement comprising:

• said cylinder head being provided with a second chamber at a lower portion thereof, means for communicating said second chamber with said discharge chamber, an oil passageway communicating between said first chamber and said second chamber, partitioning means fixedly disposed within said discharge chamber to separate said discharge chamber into a first and a second spaces, said first space being a front portion of said discharge chamber and communicating with said cylinders, said second space being a rear portion of said discharge chamber and communicating with said second chamber, said partitioning means being shorter than the inner wall of said discharge chamber at the upper portion thereof to define a first gap therebetween along the inner wall of said discharge chamber through which gap said first space communicates with said second space, said partitioning means including a first plate member fixed to said cylinder head and with conduit means connecting said first space with an outlet port of said cylinder head to be connected with an external cooling circuit, a guide wall extending along the inner surface of said discharge chamber at the lower peripheral portion of said plate member and axially projecting within said first space to define a groove along the inner surface of said discharge chamber, opposite ends of said groove connecting with said first gap, whereby the oil flowing on the inner surface of said first space may be transferred to said second space directly through said first gap and/or through said first gap after flowing in and along said groove by the compressed gas flow to said conduit, and whereby the oil separated from the compressed gas within said second space may be accumulated in said second chamber and be returned to said first chamber through said oil passageway.