Device for guiding a piston

摘要

A compressor has a front housing, cylinder block and a rear housing. The housings and cylinder block are secured to one another by a plurality of bolts. A plurality of pistons reciprocally move in cylinder bores to compress gas. Each of said bolts has a shaft extending through the housings and the cylinder block. A cam plate is supported on a drive shaft for integral rotation therewith to convert the rotation of the drive shaft to reciprocal movement of a piston in the cylinder bore. The piston rotates about its axis in accordance with rotation force transmitted from the cam plate and abuts against the shaft of the bolt, which extends in close proximity to the piston. The rotating piston abuts against the shaft so that the rotation thereof is restricted. The shaft has a diameter greater than that of a threaded portion formed at an end of the bolt. Since the threaded portion is smaller, the threaded portion does no damage to the piston during assembly.