Piston type compressor especially for coolant compression has a support surface on the piston crown to support the action of the inlet flap valve

摘要

A piston type compressor, e.g. for compression a coolant in a chiller system, has a special surface (11) on the piston crown (12) to support the free end of an inlet flap valve (8) fitted to the inside of the end of the cylinder. The support surface is harder and smoother than the rest of the crown and can be profiled (16) to support the end of the flap valve. The initial opening movement of the flap valve is limited by the speed of the piston thereby reducing valve fatigue. The profiling of the support surface provides a convex support for the flap valve. The support surface can be made of ceramic or PTFE.