JPH10295050A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent electromagnetic vibration generated by a stator from being transmitted to a vibration generated by a stator from being transmitted to a bracket by a method, wherein a protrusion is formed on the outer circumferential face of the stator, in which a displacement by the electromagnetic vibration on the outer circumferential face of the stator becomes zero or close to zero and the stator is housed, via the protrusion, in the inner circumferential part of the bracket so as to be fixed. SOLUTION: A stator core 1 is constituted of a ring-shaped back yoke and of teeth which protrude to the shaft center from the inner circumferential face of the back yoke, and a plurality protrusion 4 are formed on the outer circumferential face of the back yoke. As the positions of the protrusions 4, positions in which a power supply are supplied to a coil so as to generate an electromagnetic vibration, in which a displacement in an arbitrary position on the outer circumferential face of the stator core is measured and in which the displacement of the electromagnetic vibration becomes minimum are selected. When the protrusions 4 are formed in this manner, a stator 5 is attached to a bracket 9 at a place in which the displacement by the electromagnetic vibration on the outer circumferential face of the stator core 1 becomes minimum, and the electromagnetic vibration which is transmitted to the bracket can be suppressed to a minimum.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric motor having a stator housed in a steel plate bracket.

[0002]

2. Description of the Related Art A conventional DC motor having a stator housed in a steel plate bracket will be described with reference to FIG. FIG. 5 is a partial cross-sectional view of a conventional DC motor.

In FIG. 5, a DC motor 11 includes a stator 12, a rotor 13 housed in an inner peripheral portion of the stator 12, and rotatably mounted, a bracket 14 housing the stator 12, and the like. It is configured. Further, the outer peripheral surface of the stator 12 is fixed to the inner peripheral surface of the bracket 14 by press-fitting or bonding. This bracket 14
It plays a role of fixing and protecting the stator 12, the rotor 13, and the like, and is also used as a fixing member for fixing the DC motor 11 to another device.

The stator 12 includes a stator core 1 having a ring-shaped back yoke 15 and teeth 16 extending from the inner periphery of the back yoke 15 toward the axial center.
7, a coil 18 wound around the teeth 16 of the stator core 17, and a coil insulating material 19 provided between the stator core 17 and the coil 18 for electrical insulation.

The rotor 13 includes a shaft 20 and a cylindrical yoke 21 mounted on the outer peripheral surface of the shaft 20.
And the permanent magnet 2 attached to the outer periphery of the yoke 21
And 2.

Power is supplied to the coil 18 wound around the stator core 17 to generate a magnetic field and rotate the rotor 12.

[0007]

As described above, in the conventional electric motor, the entire outer peripheral surface of the stator is press-fitted or adhered to the inner peripheral surface of the bracket. When power is supplied to the electric motor, the rotor rotates, but at this time, the stator generates electromagnetic vibration. And this electromagnetic vibration,
When transmitted to a steel plate bracket, the bracket may resonate and cause noise.

[0008]

Therefore, according to the present invention, a protrusion is provided on the stator outer peripheral surface where the displacement of the electromagnetic vibration of the stator outer peripheral surface becomes zero or near zero, and the stator is fixed via the protrusion. An electric motor characterized in that a child is mounted on a bracket.

[0009]

The stator is housed in the inner peripheral portion of the bracket through the projection provided on the outer peripheral surface of the stator, and is fixed, thereby making it difficult to transmit the electromagnetic vibration generated by the stator to the bracket.

[0010]

An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a front view of a stator core according to the present invention. FIG. 2 is a front view of the stator according to the present invention. FIG. 3 is a graph illustrating the displacement of the vibration on the outer peripheral surface of the stator. FIG. 4 is a partial sectional view of the DC motor according to the present invention.

In FIG. 1, a stator core 1 comprises a ring-shaped back yoke 2 and teeth 3 extending from the inner peripheral portion of the back yoke 2 toward the axis. A plurality of projections 4 are provided on the outer peripheral surface.

In FIG. 2, the stator 5 comprises a stator core 1, a coil 6 wound around teeth 3 of the stator core 1, and the like, similarly to the stator described in the conventional example. .

When power is supplied to the coil 6,
A magnetic field is generated, and a magnetic flux passing through the stator core 1 is generated. By changing the direction of the current flowing through each coil in a predetermined order, the rotor 7 can be rotated.

When power is supplied to the coil 6 and a magnetic flux is generated, an electromagnetic vibration is generated in the stator 5. Then, as described above, by changing the direction of the current flowing through each coil 6, that is, the teeth 3
The rotor 7 is rotated by changing the poles (N-pole and S-pole) generated in the stator core. Therefore, the displacement of the electromagnetic vibration measured on the outer peripheral surface of the stator core 1 is expressed by The direction of the vibration is reversed at the place where it occurs.

FIG. 3 is a graph in which power is supplied to the coil 6 to generate electromagnetic vibration and the displacement of the electromagnetic vibration at an arbitrary position on the outer peripheral surface of the stator core 1 is measured. Therefore, the protrusion 4 may be provided at a position where the displacement of the electromagnetic vibration is minimized.

Referring to FIG. 4, a DC motor 8 includes a stator 5 having a projection 4 on the outer periphery, a rotor 7 housed in the inner periphery of the stator 5 and rotatably mounted, and a stator 7. 5 The projection 4 on the outer peripheral surface is constituted by a bracket 9 or the like which is press-fitted or adhered to the inner peripheral surface formed in a cylindrical shape.

By providing the projections 4, the stator 5 is mounted on the bracket 9 at the position where the displacement of the electromagnetic vibration on the outer peripheral surface of the stator core 1 is minimum. Vibration can be minimized.

[0018]

According to the present invention, the amount of electromagnetic vibration generated when the electromagnetic vibration generated from the stator is transmitted to the bracket can be reduced.

[0019]

[Brief description of the drawings]

FIG. 1 is a front view of a stator core according to the present invention.

FIG. 2 is a front view of a stator according to the present invention.

FIG. 3 is a graph illustrating a displacement of vibration on an outer peripheral surface of a stator.

FIG. 4 is a partial sectional view of a DC motor according to the present invention.

FIG. 5 is a partial sectional view of a conventional DC motor.

[Description of Signs] 1, 17 ... Stator core 2, 15 ... Back yoke 3, 16 ... Teeth 4 ... Projection 5, 12 ... Stator 6, 18 ... Coil 7, 13 ... Rotor 8, 11 ... DC motor 9 , 14 ... bracket 19 ... insulating material 20 ... shaft 21 ... yoke 22 ... permanent magnet

Claims (1)

[Claims] An electric motor having a stator housed in a bracket made of steel plate, wherein a projection is provided on an outer peripheral surface of the stator where the displacement of electromagnetic vibration on the outer peripheral surface of the stator is zero or near zero. An electric motor characterized in that a stator is attached to a bracket via a bracket.