Piston type compressor

A piston type compressor comprising a drive shaft rotatably supported on a housing, the housing including a cylinder block, the cylinder block including a cylinder bore and a valve accommodating chamber communicating with a suction communicating passage, wherein reciprocation of a piston operably connected to the drive shaft in the corresponding cylinder bore changes the volume of a compression chamber in the cylinder bore to compress gas supplied from a first region through the suction communicating passage, on which a suction pressure acts, to the compression chamber, wherein the compressed gas is sent to a second region, on which a discharge pressure acts, the compressor comprising:

• a rotary valve accommodated in the valve accommodating chamber, wherein the rotary valve has a suction guiding groove which is communicated with the first region, wherein the rotary valve rotates integrally with the drive shaft to selectively open or close a passage of gas from the first pressure region to the compression chamber in accordance with relative positions of the suction communicating passage and the suction guiding groove, wherein the rotary valve has a substantially cylindrical shape and an outer surface, wherein the valve accommodating chamber has a circular cross-section and an inner surface, wherein the outer surface and the inner surface constitute slide bearing surfaces for receiving a radial load applied to the drive shaft by sliding on each other.