Patent ID: 6071092
Filing Date: 2000-06-06
Classification: F04D,F16C

Abstract:
A vacuum pump with a back-up bearing assembly having a rotor pumping section mounted to a rotor drive shaft and a primary bearing system, said back-up bearing assembly comprising:an axially elongated center shaft having one end proximal to a rotor pumping section and another end distal from a rotor pumping section;annular bearings fitted on and attached to said center shaft;a sensor located near the distal end of said center shaft for detecting the position of said rotor drive shaft with respect to said center shaft;said rotor drive shaft having a tubular hollow cavity with an open end, sidewalls and a closed end, said tubular hollow cavity being distal from said rotor pumping section;said center shaft and said annular bearings being disposed inside said tubular hollow cavity and positioned coaxially with said rotor drive shaft;a metal ring secured to the open end of said tubular hollow cavity, anda unit for restricting the movement of said annular bearings along an axis of said rotor drive shaft, said unit being attached to said metal ring;wherein the sidewalls of said rotor drive shaft frictionally engage said annular bearings when said primary bearing system becomes disabled.