Filing Information

Inventor(s)	Jack W. Savage · Thomas J. Savage ·
Assignee(s)	General Motors Corporation ·  View assignee updates
Attorney/Agent(s)	Edward P. Barthel ·
Primary Examiner	William L. Freeh ·
Application Number	US5732927
Filing date	10/15/1976
Issue date	08/08/1978
Predicted expiration date	10/15/1996
U.S. Classifications	417/238  · 417/273  ·
International Classifications	F04B 1900  ·
Kind Code	A
International Classifications	417273;271;539;238 ·

Patent Family

Abstract

A refrigerant compressor constructed for the addition of one or more pumping cylinders for the change of capacity. Improved mechanical efficiency is attained by means of a motor-driven eccentric cam imparting linear motion through one or more of the compressor pistons to the compression stroke and wherein the work to reciprocate each piston is assisted by dual out-of-phase compression springs. The cam is configured for producing a predetermined dwell-period when each piston reaches its bottom-dead-center position wherein a maximum gas charge will be inducted into the cylinder bore by the ram velocity effect of the inward moving gas stream. In a like manner the cam design provides piston dwell time at its top-dead-center position wherein an increased gas charge will be expelled per cycle resulting in increased volumetric efficiency.

Independent Claims | See all claims (4)

1. 1. A compressor of selectable configuration for changing the capacity thereof, said compressor comprising an exposed mounting surface having four mounting positions thereon around a drive shaft which is normal thereto, each of said mounting positions adapted to receive interchangeably thereat one of four identical cylinder assemblies, each of said cylinder assemblies selectively mountable on said surface in any of said mounting positions singly or in multiples of two, three or four such assemblies, said drive shaft having affixed thereto an eccentric cam the periphery of which rotates in a plane parallel to said mounting surface and is exposed thereon, each of said cylinder assemblies comprising a cylinder bore selectively opened and closed at an outboard end thereof by intake and exhaust valve means and closed at an inboard end thereof by a guide member, a piston reciprocable in said cylinder bore and having a piston rod affixed at one end to said piston and slidably received in said guide member, said piston rod having an exposed cam follower affixed to the other end thereof sandwiching a spring between said cam follower and said guide member to bias said piston toward said inboard end of the cylinder bore and said cam follower against the exposed periphery of said cam when said cylinder assembly is in any of said four mounting positions.
2. 2. A compressor of selectable configuration for changing the capacity thereof, said compressor comprising an exposed mounting surface having four mounting positions thereon around a drive shaft which is normal thereto, each of said mounting positions adapted to receive interchangeably thereat one of four identical cylinder assemblies, each of said cylinder assemblies selectively mountable on said surface in any of said mounting positions singly or in multiples of two, three or four such assemblies, said drive shaft having affixed thereto an eccentric cam the periphery of which rotates in a plane parallel to said mounting surface and is exposed thereon, each of said cylinder assemblies comprising a cylinder bore selectively opened and closed at an outboard end thereof by intake and exhaust valve means and closed at an inboard end thereof by a guide member, a piston reciprocable in said cylinder bore and having a piston rod affixed at one end to said piston and slidably received in said guide member, said piston rod having an exposed cam follower affixed to the other end thereof sandwiching a spring between said cam follower and said guide member to bias said piston toward said inboard end of the cylinder bore and said cam follower against the exposed periphery of said cam when said cylinder assembly is in any of said four mounting positions, said cam periphery having a sinusoidal configuration thereon producing a predetermined dwell-period when each piston reaches its bottom-dead-center position in its cylinder bore, whereby a maximum gas charge will be inducted into the bore through its intake valve means by virtue of the ram velocity effect of the inward moving gas stream, and said cam periphery producing a predetermined dwell-period when each piston reaches top-dead-center position in its bore, whereby a maximum gas charge will be expelled through its exhaust valve means resulting in increased volumetric efficiency of said compressor.
3. 4.4. A radial compressor for a gas including a support member having a unit axis, a bored cylinder fixed on said support member, said cylinder having the axis of its bore in a transverse plane and having the inner end of said bore closed by a guide member, a drive shaft on said unit axis having one end rotatably mounted in said support member with said unit axis normal to said transverse plane, a cam member eccentrically mounted on said drive shaft for rotation therewith in said transverse plane, a piston slidable in said bore, said piston having a piston push rod extending through an aperture in said guide member, said piston rod having a cam follower member on its inner end portion cooperating with said cam member so that said piston moves radially outwardly to its top-dead-center position when said shaft rotates, said piston rod having a coiled wire compression spring positioned concentrically thereon between its cam follower member and said guide member such that said spring is compressed between its cam follower member and said guide member as said piston moves radially outwardly to its top-dead-center position when said shaft rotates, and the outer end of said cylinder bore having suction and discharge valve means for inducting and expelling gas, said cam member having a variable curvature peripheral surface thereon engaging said cam follower member, said surface configured with a first curvature in one location to produce a predetermined first dwell-period when said piston reaches its bottom-dead-center position, whereby a larger charge of gas to be compressed per cycle will be inducted into the bore through said intake valve means by virtue of the ram velocity effect of the inward moving gas stream, and said peripheral surface of said cam member configured with a second curvature in another location to produce a predetermined second dwell-period when said piston reaches said top-dead-center position, whereby a larger charge of compressed gas per cycle will be expelled through said exhaust valve means with said piston stationary at full compression for raising the volumetric efficiency of said compressor.