Lubricating structure in piston type compressor

A rotary shaft for use in a piston type compressor that has a housing including a seal chamber, a cylinder bore and a suction pressure region, and a shaft seal device located in the seal chamber, the rotary shaft comprising:

• a supply passage communicating with the suction pressure region;
• an introducing passage communicating with the supply passage for introducing fluid into the cylinder bore;
• and
• a lubricating passage interconnecting the seal chamber and the suction pressure region for introducing the fluid with lubricant in the suction pressure region into the seal chamber, the part of lubricant staying in the seal chamber.

A piston type compressor connected to an external refrigerant circuit, the compressor comprising:

• a housing defining a seal chamber, a cam chamber, a plurality of cylinder bores and a suction pressure region;
• a rotary shaft rotatably supported by the housing, the rotary shaft including a first lubricating passage that interconnects the suction pressure region and the seal chamber for introducing fluid with lubricant in the suction pressure region into the seal chamber, the part of lubricant staying in the seal chamber;
• a cam located in the cam chamber, the cam being operatively connected to the rotary shaft;
• a piston located in each of the cylinder bores, the piston engaging the cam to reciprocate in accordance with rotation of the rotary shaft through the cam;
• a rotary valve connected to the rotary shaft, the rotary valve including an introducing passage, the rotary shaft including a supply passage that interconnects the introducing passage and the suction pressure region for introducing the fluid into the cylinder bore;
• and
• a shaft seal device located in the seal chamber, the shaft seal device being located between the housing and the rotary shaft for preventing the fluid from leaking along a circumferential surface of the rotary shaft from the housing.

A lubricating structure in a piston type compressor connected to an external refrigerant circuit, comprising:

• a housing defining a seal chamber, a cam chamber, a plurality of cylinder bores and a suction pressure region;
• a rotary shaft rotatably supported by the housing, the rotary shaft including a communication passage that interconnects the suction pressure region and the seal chamber;
• a cam located in the cam chamber, the cam being operatively connected to the rotary shaft;
• a piston located in each of the cylinder bores, the piston engaging the cam to reciprocate in accordance with rotation of the rotary shaft through the cam;
• a rotary valve connected to the rotary shaft, the rotary valve including an introducing passage, the rotary shaft including a supply passage that interconnects the introducing passage and the suction pressure region for introducing the fluid into the cylinder bores;
• a shaft seal device located in the seal chamber, the shaft seal device being located between the housing and the rotary shaft for preventing fluid from leaking along a circumferential surface of the rotary shaft from the housing;
• and
• a lubricating passage interconnecting the cam chamber and the seal chamber.