Abstract: A multi-stage centrifugal compressor with an integral high-speed motor for compressing air has a variable speed permanent magnet motor having electronically commutated stator coils surrounding a rotor carrying permanent magnets, wherein there is a gap between the coils and the rotor. The rotor has a magnetic steel rotor shaft rotatably supported at each end by pressurized oil lubricated hydrodynamic bearings. The stator coils have a plurality of stator wires extending longitudinally along the stator and continuing around the ends of the stator to define end turns. The compressor also has a plurality of compressor impellers mounted to turn with the rotor shaft and cooler for cooling the bearings, rotor and stator coils comprising a pump for introducing cooled oil into the bearings, said bearing configured so that oil exiting from the bearings splashes over the supported ends of the shaft and splashes over the end turns of the stator coils.

Abstract: A multi-stage centrifugal compressor multi-stage centrifugal compressor with an integral high-speed motor for compressing air has a variable speed permanent magnet motor having electronically commutated stator coils surrounding a rotor carrying permanent magnets, wherein there is a gap between the coils and the rotor. The rotor has a magnetic steel rotor shaft rotatably supported at each end by pressurized oil lubricated hydrodynamic bearings. The stator coils have a plurality of stator wires extending longitudinally along the stator and continuing around the ends of the stator to define end turns. The compressor also has a plurality of compressor impellers mounted to turn with the rotor shaft and cooler for cooling the bearings, rotor and stator coils comprising a pump for introducing cooled oil into the bearings, said bearing configured so that oil exiting from the bearings splashes over the supported ends of the shaft and splashes over the end turns of the stator coils.

Abstract: A shaft seal assembly comprises contact seal rings which are inserted into a recess formed within labyrinth seal rings encompassing the shaft. The contact seal rings are adapted to be in sealing engagement with the shaft when the shaft is not rotating or the shaft speed is relatively slow. The contact seal rings are moved radially outward with respect to the rotary shaft when the shaft speed is increased. Buffer liquid generates the force to move the contact seal rings radially outward from sealing engagement with the shaft and at the same time establishes a barrier for process fluid when the shaft speed is increased.

Abstract: A magnetic pickup for sensing the speed of a rotor disc having a nosepiece affixed to the disc containing one or more magnets. The magnets are contained within blind openings passing inwardly from the back of the nosepiece and arranged to position the magnets within an embossed section extending axially from the outer surface thereof. A stationary sensing probe is mounted adjacent to the embossed section which is capable of generating a voltage signal as the magnets are passed in close proximity with the sensing element.