JPH10201195A - Switched reluctance motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce torque ripple to a minimum and restrain vibration and noise due to vibration, by fixing a flywheel having a suitable mass to the rotating shaft side of a rotor. SOLUTION: A disc-shaped flywheel 3 having necessary mass is fixed to a rotating shaft to which a rotor 1 is fixed. Torque ripple (rapid drop of torque) which is caused by mismatch of the number of magnetic poles of the rotor 1 and a stator 4 is compensated by the moment of inertia of the flywheel 3, so that smooth rotating operation is always realized. Since the rotating operation is maintained by using the inertia momentum of the flywheel, power-saving also can be realized by performing the ON/OFF control of power supply operation to a motor at suitable intervals. Thereby vibration and noise can be effectively prevented, and a motor of high quality and high output wherein the rotating operation is stable can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention has a large output,
Further, the present invention relates to a switched reluctance motor which has a feature of a long durability time and is suitable for application to various fields such as an electric vehicle, an electric bicycle, a crane, and a vacuum cleaner.

[0002]

2. Description of the Related Art As shown in FIG. 3, for example, a reluctance motor includes a rotor 100 having a plurality (four) of outwardly projecting magnetic poles 100A on the inside and a plurality of inwardly projecting magnetic poles 200A on the outside. (Six) stators 200, and each of the magnetic poles 200A on the stator 200 side is provided with a coil (not shown) formed by winding an appropriate winding. Are known.

Usually, the convex magnetic poles on the side of the stator 200 are bilaterally symmetrical, and correspond to the relative angle difference θ between the rotor 100 and the stator 200 during rotation as shown in FIGS. Relationship (characteristic) of change in generated torque T
Is a curve as shown in FIG.

[0004]

By the way, as can be seen from FIG. 7 showing the transition of the torque, if attention is paid to a specific convex magnetic pole, the decrease in the latter half portion where the torque (solid line portion) decreases. Since the amount of fluctuation is large, even if the torque (indicated by a two-dot chain line) and the torque (indicated by a two-dot chain line) of the adjacent magnetic pole that partially overlaps due to the approach of the next convex magnetic pole is combined, the rotational force is also indicated (indicated by a one-dot chain line) However, a sudden drop in torque cannot be completely compensated. As a result, there is a problem that vibration (pulsation) or vibration sound is generated during the rotation operation due to a temporary (temporary, but very short time) sudden drop of torque (torque ripple).

[0005] In view of the above circumstances, the present invention provides a switched reluctance motor capable of reducing torque ripple as much as possible and suppressing vibration and noise accompanying the vibration. It is intended for.

[0006]

According to a first aspect of the present invention, there is provided a rotor having a plurality of outwardly projecting pole projections, and an inwardly projecting magnetic pole coil surrounding the rotor from the outside. In a switched reluctance motor, in which a plurality of stators are arranged and a rotor rotates in a fixed direction while detecting a rotor position with respect to the stator, a flywheel having an appropriate mass is attached to a rotating shaft side of the rotor. .

[0007]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic view showing a main part of a switched reluctance motor (SR motor) according to the present invention. A flywheel 3 having a disc-shaped specific mass is fixed to a rotating shaft 2 on which a rotor 1 is mounted. ing.

[0008] Assuming that the flywheel 3 of this embodiment is a disk having a radius of R, a thickness of L, and a density of γ, as shown in FIG. ² where w = πR ² · L · γ / g (g is the gravitational acceleration). The rotational energy generated by the rotation of the flywheel 3 is given by E = (1/2) Iω ² , where ω is the rotational angular velocity.

The flywheel 3 is preferably mounted at a position as far away as possible to minimize the influence of the magnetic field generated in the coil 40 on the stator 4 side. There is no problem if it is formed of a magnetic material.

Further, when driving a desired device using the switched reluctance motor (SR motor), particularly when applying to a suitable device other than a device requiring smooth operation, , A control unit may be additionally provided to control ON / OFF of the power supply to the motor at relatively small time intervals. In this case, the rotary shaft continues to rotate due to the moment of inertia of the flywheel 3 during the short pause, and the operation of the device can be continued, so that the power consumption for the short pause can be saved. .

Therefore, according to this embodiment, the torque ripple caused by the mismatch of the number of magnetic poles between the rotor 1 and the stator 4, for example, specifically, the number of magnetic poles 4 on the rotor 1 and the number of magnetic poles 6 on the stator 4 In the case of a switched reluctance motor comprising:
(Twice) The torque ripple that has occurred is compensated by the moment of inertia of the flywheel 3, so that a smooth rotation operation can be always realized.

[0012]

As described above, according to the present invention, the flywheel having an appropriate mass is attached to the rotating shaft side of the rotor, and the difference in the relative angle between the rotor and the stator is zero. However, since the drop of the torque component in the rotational direction of the rotor can be sufficiently compensated for by the moment of inertia of the flywheel, the torque ripple is reduced by that amount, and the vibration and noise accompanying this can be effectively prevented. What is quiet, smooth rotation, small size and high output? ? In other words, it is possible to provide a high-quality, high-output switched reluctance motor whose rotation operation is stable.

Further, according to the present invention, since the rotation operation is maintained by utilizing the inertia force of the flywheel, the power supply operation to the motor is turned on at appropriate intervals.
By performing the / OFF control, there is an effect that power can be saved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an SR motor according to the present invention.

FIG. 2 is a perspective view showing a flywheel of the motor.

FIG. 3 is a schematic configuration diagram showing a conventional SR motor.

FIG. 4 is an explanatory view showing the operation of a conventional SR motor.

FIG. 5 is an explanatory view of the same.

FIG. 6 is an explanatory view of the same.

FIG. 7 is a graph showing torque characteristics of a conventional SR motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotor 2 Rotation axis 3 Flywheel 4 Stator

Claims (1)

[Claims] 1. A rotor having a plurality of outwardly projecting pole projections, and a stator having a plurality of inwardly projecting magnetic pole coils surrounding the rotor from outside, and detecting a rotor position with respect to the stator. A switched reluctance motor that rotates in a fixed direction while attaching a flywheel having an appropriate mass to the rotating shaft side of the rotor.