Brushless motor

Abstract

In a brushless motor comprising an external stator constituted by electrically forming a magnetic circuit by winding wire on a core, a bus bar forming an external input terminal by tying the wound wire together, and an internal rotor integrated with a permanent magnet and rotatably supported to the external stator through bearings, an insulating plate is held at one end side of the external stator, and a magnetic pole sensor for detecting the magnetic pole of the permanent magnet is attached to the insulating plate.

Description

technical field [0001] The present invention relates to a brushless motor used as a driving source of, for example, an EGR (Exhaust Gas Recirculation) valve, a VG (Variable Geometry, variable geometry) turbine actuator, and the like. Background technique [0002] The brush motor (commutator motor) uses a commutator to switch the electrical contacts mechanically. Unlike the brushless motor, the direction of the current is switched from the controller side, so in order to switch the direction of the current , It is necessary to detect the magnetic poles of the permanent magnets used in the inner rotor of the brushless motor. In order to simplify this magnetic pole detection and reduce costs, a magnetic pole sensor such as a Hall element is used. [0003] Therefore, in the past, the axial length of the permanent magnet used in the inner rotor was extended to the position where the magnetic pole sensor could detect the magnetic pole (Patent Document 1); or other magnets and magn...

AI Technical Summary

Problems solved by technology

Therefore, it is difficult to align the positions of the external stator and the magnetic pole sensor since the positions of the external stator and the magnetic pole sensor are determined in the final assembly process

Also, since the magnetic pole sensor is generally constituted by a chip or the like, there is a problem that electrical insulation etc. are required with respect to the external stator

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