Abstract: A rotary compressor including a housing, a first scroll member, a second scroll member in meshing engagement with the first scroll member, and an Oldham coupling coupled to the second scroll member to inhibit the relative rotational movement between the first scroll member and the second scroll member. The Oldham coupling including a first riding pad, a second riding pad, a third riding pad is positioned, and a fourth riding pad positioned such that the first riding pad and the fourth riding pad are in an overlapping arrangement.

Abstract: A rotary compressor including a housing, a first scroll member, a second scroll member in meshing engagement with the first scroll member, and an Oldham coupling coupled to the second scroll member to inhibit the relative rotational movement between the first scroll member and the second scroll member. The Oldham coupling including a first riding pad, a second riding pad, a third riding pad is positioned, and a fourth riding pad positioned such that the first riding pad and the fourth riding pad are in an overlapping arrangement.

Abstract: An oil-less/oil-free air brake compressor comprising a bore, a piston positioned for reciprocating in the bore, the piston having an annular recess and a rigid polymeric piston ring received within the annular recess, the piston ring having a predetermined non-circular profile in the free state.

Abstract: An oil-free/oil-less air compressor with a piston positioned for reciprocating in a bore, the piston having a first piston ring assembly made from a rigid, high temperature polymer, and a second piston ring assembly comprising a first portion that engages the bore, the first portion made from a relatively soft, self-lubricating polymer, and a second portion that biases the first portion against the bore.

Abstract: An oil-free/oil-less air compressor with a piston positioned for reciprocating in a bore, the piston having a first piston ring assembly made from a rigid, high temperature polymer, and a second piston ring assembly comprising a first portion that engages the bore, the first portion made from a relatively soft, self-lubricating polymer, and a second portion that biases the first portion against the bore.

Abstract: An oil-less/oil-free air brake compressor comprising a bore, a piston positioned for reciprocating in the bore, the piston having an annular recess and a rigid polymeric piston ring received within the annular recess, the piston ring having a predetermined non-circular profile in the free state.

Abstract: A cylinder is divided into two chambers by a wall to receive a pair of pistons. This reduces the stroke length and correspondingly reduces the linear speed of the piston. This leads to a reduced PV factor associated with degradation and wear of the piston rings. Moreover, the multi-cylinder arrangement provides the same performance in an oil-free compressor assembly without appreciably expanding dimensional constraints relative to known systems.

Abstract: A scroll machine has an elastomeric member placed between the drive shaft and an unloader drive bushing of the scroll machine. The elastomeric member provides limited transverse movement between the drive shaft and the orbiting scroll member which is driven by the drive bushing. The limited transverse movement permits radial compliant engagement of the scroll wraps of the scroll machine. In one embodiment, the elastomeric member is connected to the drive shaft and a bearing plate is placed between the elastomeric member and the drive bushing for driving engagement. In another embodiment, the elastomeric member is connected to the drive bushing and a bearing plate is placed between the elastomeric member and the drive shaft for driving engagement.