CAM AND CRANK ENGAGEMENT FOR A REVERSIBLE, VARIABLE DISPLACEMENT COMPRESSOR AND METHOD OF OPERATION THEREOF

摘要

A reversible reciprocating piston compressor includes a crankcase defining a t least one cylinder therein and a crankshaft rotatably supported by the crankcase. The crankshaft includes a drive portion and a crankpin eccentrically positioned relative to an axis of rotation of the crankshaft. A piston is reciprocable within the cylinder and a connecting rod assembly is provided between the crankpin and the piston to reciprocally drive the piston in response to forward or reverse rotation of the crankshaft. A cam assembly is operably connected to the crankpin and is engageable with the drive member to effectuate a first strok e length in a first direction of rotation of the crankshaft and a second stroke in a second direction of rotation of the crankshaft. The cam assembly includes a cam, a driven portion and a counterweight. The cam is interposed between the connecting rod assembly and the crankpin and t he driven portion is attached to the cam and is in a contacting relationship with the drive portion through at least one contact interface. The contact interface is oriented at a non-zero angle to a radial reference originating from a centerline axis of the crankpin. The counterweight is attached to the cam and has a center of mass located radially adjacent to or through the contact interface. Thedrive portion is engageable and disengageable with the driven portion through sliding movement of the drive portion relative to the driven portion along the contact interface.