Patent ID: 6220146
Filing Date: 2001-04-24
Classification: F04B

Abstract:
A single-headed-piston type refrigerant compressor comprising:a cylinder block provided with a plurality of parallel cylinder bores formed therein and having front and rear ends;a front housing covering the front end of said cylinder block and defining a crank chamber therein;a drive shaft supported on said cylinder block and said front housing to be rotatable about an axis of rotation;a rear housing covering the rear end of said cylinder block and defining, therein, a suction chamber for a refrigerant before compression and a discharge chamber after compression; a cam plate arranged around said drive shaft to be rotatable together with said drive shaft; anda plurality of single-headed pistons fitted for linear motions in said plurality of cylinder bores, respectively, each being engaged, via a pair of shoes, with said cam plate to be moved linearly in one of said cylinder bores in response to rotation of said cam plate,wherein each of said single-headed pistons comprises:a piston head portion sliding in said cylinder bore and having a compressing end to compress the refrigerant and a base end opposite to said compressing end;a shoe-holding portion arranged adjacent to said base end of said piston head portion and formed as a substantially longitudinal U-shape-cross-sectional portion having opposing inner faces defining a pair of engaging recesses to receive said pair of shoes therein; anda projecting portion formed as a rotation-preventing portion for preventing the single-headed piston from turning about its own axis, said projecting portion extending from said shoe-holding portion in a direction away from said piston head portion, and having a rotation-preventing face partially protruding in a radially outward direction beyond an outer circumference of said piston head portion so as to be in contact with a stationary part of said compressor to prevent said single headed piston from turning about its own axis, andwherein said cylinder block comprises:an extended bore-forming portion defining a cylindrical guide surface able to permit at least said outer circumference of said piston head portion to slidably move thereon, said extended bore-forming portion being arranged to extend from a peripheral portion of said front end of said cylinder block toward said crank chamber.