Patent ID: 6287088
Filing Date: 2001-09-11
Classification: F04C

Abstract:
An oil free screw compressor comprising a compressor main body having a male rotor and a female rotor which are received in a casing and meshed with each other, first and second bearings for supporting the male rotor and the female rotor, and a shaft sealing apparatus for preventing an oil from entering into a compression chamber formed by said casing, the male rotor and the female rotor; and a high speed motor driven by a high frequency inverter and connected to a suction side of said compressor main body, said high speed motor having a motor shaft in which the motor rotor is formed, a third bearing for rotating and supporting the motor shaft and a second shaft sealing apparatus for preventing a lubricating oil for lubricating the third bearing from entering within the high speed motor; said first, second and third bearings being made the same with respect to each other, and said first shaft sealing apparatus and said second shaft sealing apparatus being made the same.