Variable capacity wobble plate compressor

Claim 2

A compressor comprising means defining a plurality of gas working spaces each having a piston cooperating with suction and discharge ports to compress a fluid therein; a drive shaft; a cam mechanism driven by said drive shaft; a wobble plate driven by said cam mechanism in a nutating path about the drive shaft axis; means operably connected between said wobble plate and the individual pistons to impart reciprocating drive to said pistons, the length of stroke being a function of the angle at which said wobble plate is supported relative to the drive axis; means for pivoting said wobble plate at a point spaced from said drive axis so as to permit said wobble plate to be inclined relative to a plane normal to said drive shaft axis, so that when the wobble plate is disposed in said normal plane, the pistons are located at top-dead-center within said gas working spaces; means for producing a substantially constant force biasing said wobble plate away from said normal plane to increase the length of stroke; a fluid tight housing enclosing said pistons and confining the fluid bypassing said pistons from said gas working spaces such that the fluid pressure in said housing is applied to the underside of each said piston to produce a force urging said wobble plate toward said normal plane; and pressure control means adapted to control the pressure in said housing in response to capacity requirements of said compressor.

Claim 3

A compressor as defined in claim 1 wherein the pressure in said housing is maintained in the range of 5-10 percent of the difference between discharge and suction pressure.

Claim 4

A compressor comprising means defining a plurality of gas working spaces arranged in spaced relation along generally parallel axes, each gas working space being provided by a stationary cylinder, and a piston cooperating with suction and discharge ports to compress a gaseous fluid therein; a wobble plate driven in a nutating path by a rotating cam member; said wobble plate being supported at a point spaced from its central axis and being pivotable from a first plane wherein said wobble plate lies substantially normal to the axis of said gas working spaces to a second plane wherein said wobble plate is substantially inclined relative to said first plane; means for connecting said wobble plate to said individual pistons to impart reciprocating motion to said pistons, the length of stroke being a function of the angle at which said wobble plate is supported relative to said working space axes; means for maintaining a substantially constant force urging said wobble plate in a direction toward said second position; housing means providing a substantially closed crankcase, the pressure in said crankcase being applied to the underside of each said piston, the gaseous fluid by-passing said pistons into said crankcase developing a pressure, subject to modulating control, for opposing the force tending to urge said wobble plate from said first plane to said second plane.

Claim 5

A compressor comprising means defining a plurality of gas working spaces arranged in spaced relation along generally parallel axes, each gas working space being provided by a stationary cylinder, and a piston cooperating with suction and discharge ports to compress a gaseous fluid therein; a wobble plate driven in a nutating path by a rotating cam member; said wobble plate being supported at a point spaced from its central axis and being pivotable from a first plane wherein said wobble plate lies substantially normal to the axis of said gas working spaces to a second plane wherein said wobble plate is substantially inclined relative to said first plane; means for connecting said wobble plate to said individual pistons to impart reciprocating motion to said pistons, the length of stroke being a function of the angle at which said wobble plate is supported relative to said working space axes; means for maintaining a substantially constant force urging said wobble plate in a direction toward said second position; housing means providing a substantially closed crankcase, the pressure in said crankcase being applied to the underside of each said piston, the gaseous fluid by-passing said pistons into said crankcase developing a pressure, subject to modulating control, for opposing the force tending to urge said wobble plate from said first plane to said second plane.

Claim 8

A compressor comprising a housing; means defining a plurality of gas working spaces each having a movable piston cooperating with suction and discharge ports to compress a fluid therein; a drive shaft; a cam mechanism driven by said drive shaft; A wobble plate driven by said cam mechanism, said cam mechanism including a drive ring rotatably driven by said drive shaft and adapted to pivot around a point along the drive axis such that the drive ring may be inclined relative thereto, and a bearing assembly interconnecting said wobble plate and said drive ring such that the wobble plate follows a nutating motion when so inclined; a plurality of connecting rods operably connecting said wobble plate and the individual pistons; a universal joint assembly including a yoke connected to said wobble plate at two points along a first axis; means for connecting said yoke to an axially movable member along a second axis disposed at right angles to said first axis whereby said wobble plate is free to pivot about both of said axes to permit nutating movement relative to said drive axis; and an annular element carried by said drive ring providing a substantial mass radially outwardly of said drive shaft axis and between said drive ring pivot point and said gas working spaces to balance the wobble plate when the same is inclined relative to the drive axis and maintain the center of gravity of the rotating elements in the drive ring assembly close to said drive ring pivot point.

Claim 9

A compressor comprising a housing; means defining a plurality of gas working spaces each having a movable piston cooperating with suction and discharge ports to compress a fluid therein; a drive shaft; a cam mechanism driven by said drive shaft; A wobble plate driven by said cam mechanism, said cam mechanism including a drive ring rotatably driven by said drive shaft and adapted to pivot around a point along the drive axis such that the drive ring may be inclined relative thereto, and a bearing assembly interconnecting said wobble plate and said drive ring such that the wobble plate follows a nutating motion when so inclined; a plurality of connecting rods operably connecting said wobble plate and the individual pistons; a universal joint assembly including a yoke connected to said wobble plate at two points along a first axis; means for connecting said yoke to an axially movable member along a second axis disposed at right angles to said first axis whereby said wobble plate is free to pivot about both of said axes to permit nutating movement relative to said drive axis; and an annular element carried by said drive ring providing a substantial mass radially outwardly of said drive shaft axis and between said drive ring pivot point and said gas working spaces to balance the wobble plate when the same is inclined relative to the drive axis and maintain the center of gravity of the rotating elements in the drive ring assembly close to said drive ring pivot point.

Claim 10

Apparatus as defined in claim 5 including counterweights connected to said wobble plate to maintain the center of gravity of said nutating elements close to said drive ring pivot point.

Claim 11

A compressor as defined in claim 6 including a reaction ring rotatable with said drive ring and said drive shaft; and means for pivotally supporting said balance ring from said reaction ring, whereby the reaction forces are transmitted through the reaction ring to the housing.