Two-speed compressor

Claim 1

In a refrigerant compressor including compression mechanism within a sealed outer casing, said compression mechanism including an upright crankshaft means having at least one longitudinally extending pump passage therein offset from the rotational axis of the crankshaft means for supplying lubricant to surfaces to be lubricated, motor means within the outer cAsing for actuating the compression mechanism, and a lubricant sump in the compressor, the improvement characterized by said motor means comprising a four-pole two-winding drive motor for driving the compression mechanism at a first high speed and a second lower speed to control capacity of the compressor, two-pole operation providing said high speed and four-pole operation providing said lower speed, and a two-stage pump mechanism operatively driven by the drive motor for assuring adequate lubrication whether the drive motor is operating at said high speed or said lower speed, said pump mechanism including means defining first inlet opening means offset from the rotational axis of the crankshaft means for ingesting lubricant from the sump, a first-stage pressurizing opening transversely disposed in said crankshaft means, said first-stage pressurizing opening communicating with said first inlet opening means, a second-stage pressurizing opening transversely disposed in said crankshaft means, passage means communicating with said first-stage pressurizing opening with said second-stage pressurizing opening, said second-stage pressurizing opening also communicating with said pump passage, the two-stage pump mechanism assuring adequate lubrication of said surfaces to be lubricated at said lower speed operation of said drive motor.