A vacuum pump and a temperature control device are capable of preventing, with a simple configuration, overheating and overcooling of a pump that are caused due to abnormality in a temperature sensor used to control a heater or a water-cooling solenoid valve that is provided to prevent the deposition of products. Problems such as overheating and overcooling of a heater can be avoided in a case where a temperature sensor system fails and consequently the measured temperature continues to be constant between the upper limit and the lower limit. TMS function controls the measured temperature of the temperature sensor to a target temperature. Thus, if an application such as a target to be heated or a heater capacity is identified, the same cycles of turning ON/OFF of the heater or the water-cooling solenoid valve are repeated, and the upper limit of the time in which the ON/OFF state is sustained continuously is determined. An allowed time considering a margin is provided for this upper limit, and the ON/OFF state is changed so that the ON state or the OFF state is not continuously sustained beyond the allowed time.

A vacuum pump comprises: a rotary body including a rotor blade and a rotor shaft; a case rotatably housing the rotary body; a motor configured to drive the rotor shaft of the rotary body; a bearing arranged at an end portion of the rotor shaft; and at least three balance correction portions including a first balance correction portion provided on one end side of the rotary body in an axial direction, a second balance correction portion provided on the other end side of the rotary body in the axial direction, and a third balance correction portion provided between the first balance correction portion and the second balance correction portion. Balance correction by an n-plane method, where n≥3, is available such that any of the three balance correction portions is accessible from an outside of the case.

A magnetic bearing control apparatus and a vacuum pump which do not require a displacement sensor, which enable control with high accuracy, and which are small and low cost. A rate of change (di/dt) that is a time derivative of a current value I.sub.m flowing through an electromagnet varies in accordance with a magnitude of a displacement of a gap between a target member and the electromagnet. The rate of change (di/dt) can be obtained by detecting a voltage value V.sub.s that is generated at both ends of an inductive element. Therefore, by detecting the voltage value V.sub.s, the magnitude of the displacement of the gap can be estimated by calculation. Inductive elements are connected in series to electromagnets and the voltage V.sub.s between the inductive elements is detected by the differential input amplifier. A single period of switching of a PWM switching amplifier is constituted by a current control period of the electromagnet and a displacement detection period for detecting the rate of change (di/dt). In addition, the displacement detection period is further constituted by a current increase period and a current decrease period which are certain periods of time. The current increase period and the current decrease period are equal to each other.

A turbomolecular pump has a housing, a rotor shaft supported by a plurality of bearings for rotation relative to the housing about an axis of rotation, a deflector, a lubricant supply system and a lubricant transfer device provided on the rotor shaft. The bearings include a rolling bearing that receives lubricant from the lubricant supply system to via the lubricant transfer device. The rolling bearing is disposed intermediate the lubricant transfer device and the deflector and the deflector is configured to deflect lubricant that passes through the rolling bearing outwardly with respect to the rotor shaft.

A rolling bearing includes an inner ring, an outer ring, rolling elements, and a retainer that holds the rolling elements. The retainer includes a metal portion and a sliding resin portion The metal portion has communication holes each having a plurality of openings on the surface of the metal portion, and the sliding resin portion is disposed in the communication holes.

A turbomolecular pump has a housing, a rotor shaft supported by a plurality of bearings for rotation relative to the housing about an axis of rotation, a deflector, a lubricant supply system and a lubricant transfer device provided on the rotor shaft. The bearings include a rolling bearing that receives lubricant from the lubricant supply system to via the lubricant transfer device. The rolling bearing is disposed intermediate the lubricant transfer device and the deflector and the deflector is configured to deflect lubricant that passes through the rolling bearing outwardly with respect to the rotor shaft.

A thrust foil bearing includes: a base plate including an insertion hole through which a shaft is inserted, and a supporting surface expanding in a direction orthogonal to an axial direction of the insertion hole; a step member placed on the supporting surface and formed of a different body from the base plate; and a back foil extending in a circumferential direction of the insertion hole and in which one part of the back foil is supported by the supporting surface and another part of the back foil next to the one part in the circumferential direction is supported by the step member.

Lubricant supply system comprising a lubricant container body defining a lubricant reservoir wherein the lubricant container body comprising an indentation of through-hole to receive a lubricant transfer device of a vacuum pump. Therein, the indentation of through-hole is surrounded by a collar extending from the lubricant container body.

A vacuum pump exhaust system and an exhausting method of the vacuum pump supply a purge gas to the vacuum pump such that an amount of the purge gas satisfies one of following conditions: an amount of the purge gas flowing at a higher velocity than a backflow velocity of gas exhausted by the vacuum pump on at least a part of a downstream side of the temperature sensor unit, and an amount of the purge gas having a pressure of one of an intermediate flow and a viscous flow around the temperature sensor unit. The exhaust system further includes a purge gas supply unit capable of controlling a flow rate of purge gas introduced into the vacuum pump. This configuration can prevent process gas from flowing backward so as to change the composition around the temperature sensor unit, thereby accurately measuring the temperature of the rotating portion.

A turbo molecular pump including multiple stages. At least one of the multiple stages of the rotor blades and the multiple stages of the stator blades is configured to satisfy any one of a first condition of Xout<Xc and Xin<Xc, a second condition of α.Math.Xc≥Xin>Xc>Xout where α=1.04, or a third condition of Xin<Xc<Xout≤β.Math.Xc where β=1.04. Xout, Xc and Xin being an inter-blade distance dived by a blade length, at an outer-diameter-side end portion, at an inner-diameter-side portion, and at an intermediate position of each blade, respectively.