Abstract: A compressor may include a shell defining an internal volume containing compressed working fluid and first and second scrolls disposed within the internal volume. The first scroll may include a first spiral wrap. The second scroll may include a second spiral wrap, a suction inlet opening and a capacity-modulation aperture. The second spiral wrap may engage the first spiral wrap to define a pocket therebetween. The suction inlet opening may be sealed off from the internal volume. The capacity-modulation aperture may receive a valve member that is movable between a first position allowing leakage of fluid from the pocket to the suction inlet opening and a second position restricting leakage of fluid from the pocket.

Abstract: A scroll machine is powered by a brushless permanent magnet motor. The rotor for the motor includes a rotor body formed by a plurality of laminations and an upper and lower counterweight made of zinc and located at opposite ends of the rotor body. An attachment member extends through the counterweights and the rotor body to secure the counterweights and the plurality of laminations. The counterweights include steel inserts which cooperate with the attachment member to provide a metal to metal clamping for the rotor body with a steel connection being maintained through the rotor.

Abstract: A refrigeration system has a compressor which incorporates fluid injection into one or more of the fluid pockets. A source of fluid for injection into the pockets is attached directly to the shell of the compressor to eliminate the need for having fluid piping between the source of fluid and the compressor. The source of fluid can be a flash tank which increases the capacity and efficiency of the system or the source of fluid can be a heat exchanger which also increases the capability and efficiency of the system.

Abstract: A refrigeration system has a compressor which incorporates fluid injection into one or more of the fluid pockets. A source of fluid for injection into the pockets is attached directly to the shell of the compressor to eliminate the need for having fluid piping between the source of fluid and the compressor. The source of fluid can be a flash tank which increases the capacity and efficiency of the system or the source of fluid can be a heat exchanger which also increases the capability and efficiency of the system.

Abstract: A scroll compressor includes a fluid injection system. The fluid injection system includes a fluid passage which extends from a position outside of the shell of the compressor to the fluid pockets created by the wraps of the scroll members. The fluid passage extends through the orbiting scroll member. The fluid injection system can be used to inject gaseous or liquid refrigerant, lubricant or the fluid injection system can be used to vent the moving pocket to the suction area of the compressor for capacity modulation.