Patent ID: 7573165

Claim:
A compressor and driving motor assembly, in which the motor is a hybrid permanent magnet motor and comprises a rotor and a stator assembly, the compressor comprising a main body supporting first and second interengaged compressor rotors; and a substantially horizontal drive shaft having first and second portions, wherein one of the first and second compressor rotors is mounted on the drive shaft first portion and the motor rotor is mounted directly on the drive shaft second portion, the drive shaft first portion being vertically supported by the compressor main body and the drive shaft second portion is free of vertical support to provide cantilever support of the motor rotor, wherein the drive shaft second portion includes a first frustoconical tapered portion tapered in a first direction and a second frustoconical tapered portion tapered in a second direction opposite the first direction, the motor rotor being mounted on the first frustoconical tapered portion by tapered fit, the first tapered portion and the second tapered portion cooperating to inhibit axial movement of the motor rotor on the drive shaft, and wherein the drive shaft drives the compressor rotor mounted thereon and the interengagement between the first and second compressor rotors drives the other compressor rotor.