JP2001095194A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of assembling processes of a motor having such a structure that the leakage of electromagnetic noise from a resin-made housing may be reduced. SOLUTION: A shielding member 13 for shielding electromagnetic noise is inserted into a resin-made housing 9 according to the positions of a brush 7a and a commutator 5a, both of which are sources of electromagnetic noise. Due to this structure, the number of components required for assembling a motor 1 can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor having a structure for reducing leakage of electromagnetic noise from a resin portion.

[0002]

2. Description of the Related Art A motor of this kind is disclosed in Japanese Unexamined Patent Publication No. 6-2614.
As disclosed in Japanese Patent Application Laid-Open No. 83-83, a metal shielding plate is attached to the outer periphery of the resin portion.
As disclosed in Japanese Patent Application Publication No. 4 (1994), a cushion member made of rubber or the like containing a material capable of absorbing electromagnetic noise is wound around the outer periphery of a resin portion. With such a shielding plate or cushion material, leakage of electromagnetic noise is reduced.

[0003]

However, the motors disclosed in the above publications have a structure in which a shield plate is attached or a cushion material is wound, so that the number of parts at the time of assembling the motor increases, and the number of assembling steps is reduced. There is a problem of increasing.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a motor having a structure for reducing leakage of electromagnetic noise from a resin housing. It is to provide a motor that can be reduced.

[0005]

According to a first aspect of the present invention, there is provided a motor having a resin housing, wherein a shielding member for shielding electromagnetic noise is provided.
It was inserted into the resin housing according to the position of the source of the electromagnetic noise.

According to a second aspect of the present invention, in the motor according to the first aspect, the shielding member is provided annularly with respect to the source of the electromagnetic noise. According to a third aspect of the present invention, in the motor according to the first aspect, the motor housing includes the resin housing and the metal housing, and the shielding member is provided so as to be continuous with the metal housing.

Therefore, according to the first aspect of the present invention,
A shielding member for shielding the electromagnetic noise is inserted into the resin housing according to the position of the source of the electromagnetic noise.
With this configuration, the electromagnetic noise scattered from the generation source to the resin housing side is shielded by the shielding member, so that leakage of the electromagnetic noise from the resin housing is reduced.
Further, since such a shielding member is inserted into the resin housing, the number of parts at the time of assembling the motor can be reduced. Therefore, the number of steps for assembling the motor is reduced.

According to the second aspect of the present invention, the shielding member is provided annularly with respect to the source of the electromagnetic noise. Therefore, the annular shielding member shields electromagnetic noise scattered from the source to the surroundings.

According to the third aspect of the present invention, the shielding member is provided in the motor housing including the resin housing and the metal housing so as to be continuous with the metal housing. Therefore, the shielding member and the metal housing cooperate to shield electromagnetic noise scattered from the source to the surroundings.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. In addition, FIG.
1 shows a motor with a speed reduction mechanism of the present embodiment. FIG. 2 shows FIG.
It is AA sectional drawing of.

As shown in FIG. 1, a motor 1 with a speed reduction mechanism
The motor unit 2 as a driving source of the motor includes a yoke housing 3 made of metal, a rotor 5 having a rotating shaft 4, a magnet 6, a brush holder 7 for supporting a brush 7a, and the like. The yoke housing 3 is formed in a bottomed cylindrical shape, and a bearing 8 is fixed to the bottom of the housing 3. The bearing 8 rotatably supports the base end (the lower end in FIG. 1) of the rotating shaft 4.

An opening 3a of the yoke housing 3 is provided with a resin-made deceleration housing 9 so as to cover the protruding rotary shaft 4.
Is assembled. Specifically, the reduction housing 9
A cylindrical fitting portion 9a is formed to fit inside the opening 3a of the yoke housing 3. The brush holder 7 is inserted into and fixed to the fitting portion 9a. The brush 7a supported by the brush holder 7 is in sliding contact with a commutator 5a provided on the opening 3a side of the rotor 5.

The inside of the speed reduction housing 9 is formed in a predetermined shape capable of accommodating a part of the rotary shaft 4 disposed therein and the worm wheel 10 and the like. Two bearings 11 and 12 are fixed in the reduction housing 9, and the center and the tip (the upper end in FIG. 1) of the rotating shaft 4 are rotatably supported by the bearings 11 and 12. Bearings 11 and 1 for rotating shaft 4
A worm 4a is formed between the worm wheels 2 and the worm 4a and the worm wheel 10 mesh with each other to form the rotating shaft 4a.
A speed reduction mechanism for transmitting a rotational force in a direction perpendicular to the direction is configured.

A metal shielding member 13 as shown in FIGS. 1 and 2 is inserted near the fitting portion 9a of the speed reduction housing 9 (near the yoke housing 3). The shielding member 13 has a predetermined length in the axial direction and an outer shape in the radial direction is formed in a substantially square cylindrical shape slightly smaller than that of the yoke housing 3. That is, the shielding member 13 is connected to the brush 7a, which is a source of electromagnetic noise, and the commutator 5a.
Around the contact portion P and the yoke housing 3
Are provided so as to continue in the axial direction.

When the motor 1 thus configured is driven to rotate, electromagnetic noise is generated between the brush 7a and the commutator 5a. At this time, the electromagnetic noise scattered from the generation source to the motor unit 2 side is shielded by the yoke housing 3 and does not leak from the housing 3 to the outside. On the other hand, most of the electromagnetic noise scattered from the source toward the deceleration housing 9 is shielded by the shielding member 13 inserted in the housing 9. for that reason,
Leakage of electromagnetic noise from the deceleration housing 9 side is reduced.

As described above, according to the present embodiment,
The following effects are obtained. (1) The resin deceleration housing 9 has a contact portion P between the brush 7a, which is a source of electromagnetic noise, and the commutator 5a.
The shielding member 13 for shielding the electromagnetic noise is inserted according to the position of. With this configuration, the electromagnetic noise scattered from the generation source to the deceleration housing 9 side is shielded by the shielding member 13, so that leakage of the electromagnetic noise from the deceleration housing 9 can be reduced.

(2) Since the shielding member 13 is inserted into the speed reduction housing 9, the number of parts when assembling the motor 1 can be reduced. Therefore, the number of steps for assembling the motor 1 can be reduced.

(3) The shielding member 13 is formed in a substantially quadrangular cylindrical shape, and is provided outside the contact portion P between the brush 7a, which is a source of electromagnetic noise, and the commutator 5a. Therefore, it is possible to reliably shield electromagnetic wave noise scattered from the source to the surroundings.

(4) The shielding member 13 is provided so as to be continuous with the yoke housing 3 made of metal in the axial direction. Therefore, the shielding member 13 and the yoke housing 3 cooperate with each other to reliably shield the electromagnetic noise scattered from the source to the surroundings.

(5) Since the shielding member 13 is made of metal,
Easy to insert molding. Note that the embodiment of the present invention may be modified as follows. In the above-described embodiment, the shielding member 13 is inserted into the resin reduction housing 9 to reduce leakage of electromagnetic noise generated between the brush 7a and the commutator 5a from the housing 9. A motor mounted with electronic components such as a coil and a capacitor may reduce leakage of electromagnetic noise generated from the electronic components. Alternatively, the present invention may be applied to a brushless motor having a circuit board on which various electronic components for controlling rotation are mounted in a housing and having no brush or commutator.

In the above embodiment, the metal shielding member 13 is formed in a substantially quadrangular cylindrical shape and is arranged at the position shown in FIGS. 1 and 2. However, if the electromagnetic noise can be sufficiently shielded, the shape of the shielding member 13 can be reduced. The position and the number of arrangements are not limited to the above embodiment. Further, the shielding member 13 may be formed of a material other than metal.

In the above embodiment, the present invention is applied to a motor having a speed reduction mechanism provided with a speed reduction mechanism in a resin housing 9, but may be applied to a motor having no speed reduction mechanism having a resin housing. .

The technical ideas other than the claims that can be grasped from the above embodiments will be described below together with their effects. (A) The motor according to claim 1, wherein a speed reduction mechanism is provided in the resin housing. In this manner, in the motor having the speed reduction mechanism, the number of assembly steps can be reduced while reducing leakage of electromagnetic noise from the resin housing.

(B) The motor according to claim 1, wherein the shielding member is made of metal. This facilitates insert molding of the resin housing.

(C) The motor according to claim 1, wherein the sources of the electromagnetic noise are a brush and a commutator. With this configuration, leakage of electromagnetic noise generated between the brush and the commutator from the resin housing can be reduced.

(D) The motor according to claim 1, wherein the source of the electromagnetic noise is an electronic component. By doing so, it is possible to reduce leakage of electromagnetic noise generated from the electronic component from the resin housing.

[0027]

As described in detail above, according to the present invention,
A motor having a structure for reducing leakage of electromagnetic noise from a resin housing, which can reduce the number of assembly steps, can be provided.

[Brief description of the drawings]

FIG. 1 is a plan view in which a part of a motor according to an embodiment is cut away.

FIG. 2 is a sectional view taken along line AA of FIG.

[Explanation of symbols]

3 ... Yoke housing as metal housing, 9 ...
A deceleration housing as a resin housing, 13 a shielding member, P a contact portion as a source of electromagnetic noise.

Claims (3)

[Claims] 1. A motor having a resin housing (9), wherein a shielding member (13) for shielding electromagnetic noise is inserted into the resin housing (9) according to the position of a source (P) of the electromagnetic noise. A motor characterized in that: 2. The motor according to claim 1, wherein the shielding member (13) is provided annularly with respect to the electromagnetic noise generation source (P). 3. The motor according to claim 1, wherein the motor housing comprises the resin housing (9) and a metal housing (3), and the shielding member (13) is connected to the metal housing (3). )
A motor provided to be connected to the motor.