Electric motor

Abstract

The invention provides an electric motor (10) which is constructed from an inner circumferential rotor (11) and an outer circumferential rotor (12) that are coaxially arranged and also from a planetary gear mechanism for rotating at least either the inner circumferential rotor (11) or the outer circumferential rotor (12) about a rotation axis (O). The motor is constructed such that, when at least either the inner circumferential rotor (11) or the outer circumferential rotors (12) is rotated by the planetary gear mechanism, a long side of a substantially oblong plate-shaped inner circumferential permanent magnet (11a) of the inner circumferential rotor (11) and a long side of a substantially oblong plate-shaped outer circumferential permanent magnet (12a) of the outer circumferential rotor (12) are opposite each other in a cross section in parallel to the rotation axis (O).

Description

technical field [0001] The present invention relates to electric motors. [0002] this application claims priority based on Japanese Patent Application No. 2005-367451 for which it applied in Japan on December 21, 2005, and uses the content here. Background technique [0003] Conventionally, there is known a motor that has, for example, first and second rotors arranged concentrically around the rotation shaft of the motor, and controls the first rotor according to the rotational speed of the motor or the speed of a rotating magnetic field generated by the stator. and the relative position in the circumferential direction of the second rotor, that is, the phase difference (for example, refer to Patent Document 1). [0004] In this motor, for example, when the phase difference between the first and second rotors is controlled according to the rotational speed of the motor, the relative positions of the first and second rotors in the circumferential direction are changed by a ...

AI Technical Summary

Problems solved by technology

[0006] However, in the electric motor in an example of the above-mentioned prior art, for example, when controlling the phase difference between the first and second rotors according to the rotational speed of the electric motor, the second rotor can only be controlled under the condition that the centrifugal force acts on the operating state corresponding to the rotational speed of the electric motor. The phase difference between the first and second rotors sometimes has the problem of not being able to control the phase difference at an appropriate moment including the stop state of the motor

In addition, when the electric motor is mounted on a vehicle as a drive source, etc., in a state where external vibrations tend to act on the electric motor, it may be difficult to properly control the phases of the first and second rotors only by centrifugal force. bad question

Furthermore, in this case, although the phase difference is controlled against the fluctuation of the power supply voltage in the power supply of the motor, for example, there may be a problem that the magnitude relationship between the power supply voltage and the induced voltage of the motor is reversed.

[0007] In addition, for example, when the phase difference between the first and second rotors is controlled based on the speed of the rotating field generated by the stator, the speed of the rotating field is changed, so there is a problem that the control of the motor becomes complicated.

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