Matsushita Electric Industrial Co., Ltd.

Isao Tashiro

Tohru Nakagawa

Yoshihiro Ikemoto

Teruo Maruyama

Katsuhiko Asai

On the stationary side of a radial bearing constructed of a plurality of magnetic poles, the magnetic poles are formed into a shape such that the magnetic flux density distribution formed between the inner surfaces of these magnetic poles and a rotor located on the rotating side of the radial bearing has a distribution inclined from the magnetic pole end portion to the magnetic pole center portion. With this arrangement, the rate of change in magnetic flux density during the shift of the rotor from a magnetic pole to the adjacent magnetic pole is reduced, thereby reducing the eddy current loss and heat generation.

Magnetic bearing

A radial electromagnetic attraction stator of a magnetic bearing system is manufactured by forming laminated core pieces as divisions of a laminated core each having a unit number of pole teeth, winding wires around pole piece portions of the laminated core pieces with insulators interposed, assembling a predetermined number of the laminated core pieces wound with the wires and fixing joined portions of the laminated core pieces. This manufacturing method prevents spaces in which the wires are wound from being limited by adjacent pole teeth unlike the conventional integral laminated core, permits winding the wires in a maximum number of turns in open spaces and allows to obtain the radial electromagnetic attraction stator having a high space factor, thereby being capable of providing a magnetic bearing system having a high load capacity and usable as a bearing capable of enhancing performance of production appliances such as working appliance and vacuum pumps.

Manufacturing method for magnetic bearing system

A second circuit B which is composed of a band-pass filter circuit (5) which takes out a rotating body position signal input from a sensor (1) while scarcely varying a phase within a range including a normal rotation frequency and a reverse rotation frequency of a rotating body, a gain circuit (6) for controlling a gain of an output signal from the bandpass filter circuit (5) and a second notch filter circuit (7) for attenuating components having frequencies lower than the natural frequency of an output signal from a gain circuit (6) is disposed separately from a main circuit A, and an output signal from the second notch filter circuit (7) is positively fed back to the main circuit A through an adding circuit (8). This composition makes it possible to obtain a magnetic bearing which is capable of sufficiently attenuating a bending natural frequency of a high-speed rotating body and supporting this rotating body with high rigidity even when a normal rotation frequency and a reverse rotation frequency of the high-speed rotating body vary.

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Hirakata, Japan

Isao Tashiro