Patent ID: 6435847
Filing Date: 2002-08-20
Classification: F04D,F16C

Abstract:
A turbo-molecular pump comprising:a pump body including a rotor, a rotor position detector, a magnetic bearing, a temperature detector and a heater; and a pump control section including a single digital signal processor programmable by software or capable of executing programmed software, wherein said rotor position detector, said magnetic bearing, said temperature detector and said heater are operatively connected to said pump control section, wherein said rotor position detector and said magnetic bearing are operatively connected to said single digital signal processor, said single digital signal processor for controlling said magnetic bearing to hold a posture of said rotor along a plurality of axes, wherein said temperature detector and said heater are operatively connected to said single digital signal processor, said single digital signal processor for controlling said heater to hold a temperature variation range based on temperature detected by said temperature detector, wherein the software includes a position control operation and a heater control operation, which is capable of setting a temperature value and a predetermined temperature variation of said pump body to hold the temperature variation range in the heater operation, the position control operation is performed to control said magnetic bearing to hold a posture of said rotor along said plurality of axes at high speed, and the heater control operation is performed at periodic intervals based on a predetermined number of performed position control operations, wherein said plurality of axes includes at least an axial direction of said rotor, a first radial direction and a second radial direction perpendicular to said first radial direction at a first position of the axial direction, and a third radial direction and a fourth radial direction perpendicular to said third radial direction at a second position of the axial direction, and wherein said temperature detecting device detects a temperature of said pump body and said heater heats said pump body.