JPH0746788A - Electric motor - Google Patents

Abstract

(57) [Summary] [Purpose] The purpose is to reduce the number of waterproofing members that are required at the ground lead wire extraction portion when the ground lead wire is taken out of the motor housing. [Structure] A motor housing (1
0a) and the ground (screw 25) of the brush holder (20) electrically connected to the motor housing (10a).
And a ground lead wire (35) connected to a screw portion (34) provided on the motor housing (10a), and a ground (screw 25) and ground lead provided on the motor housing (10a). The screw hole that connects the wire is not a through hole.

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 brush supporting device.

[0002]

2. Description of the Related Art As a conventional technique of this type of electric motor, one disclosed in Japanese Patent Laid-Open No. 3-3635 is known. This is a motor housing, a shaft supported by the motor housing, a core fixed to the shaft and wound with a coil, a commutator fixed to the shaft, and sliding in the commutator and stored in a brush box. In the electric motor having the brush and the brush holder attached to the motor housing, the ground of the brush holder accommodating the brush is connected to the lead wire, and the connected lead wire is connected to the motor housing. It was taken out.

[0003]

However, with the above technique, when the lead wire connected to the brush holder inside the motor housing is taken out of the motor housing,
In an electric motor that requires waterproofness, it is necessary to attach a waterproofing member to the portion where the lead wire is taken out.

It is an object of the present invention to reduce the number of waterproof members required at the ground lead wire extraction portion when the ground lead wire is taken out of the motor housing.

[0005]

Means for Solving the Problems The measures taken in claim 1 for solving the above problems are, in a rectifying type DC motor, a motor housing formed of a conductive member and electrically connected to the motor housing. The brush holder has a ground and a lead wire connected to a screw portion provided on the motor housing.

The means taken in claim 2 is that the screw hole for mounting the ground of the brush holder provided in the motor housing and the screw hole for connecting the external ground lead wire are not through holes.

[0007]

According to the above-mentioned means, by connecting the electrode of the brush holder to the motor housing of the conductive member,
The ground lead wire and the electrode of the brush holder can be connected via the motor housing, and the screw hole for connection for connecting the brush holder to the motor housing and the screw hole for the screw provided in the motor housing and for connecting the ground lead wire However, since it is not necessary to form the through hole, it is possible to prevent water and the like from entering through the screw hole. This eliminates the need to dispose a waterproof member for the ground lead wire extraction portion.

[0008]

Embodiments of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the electric motor includes a motor housing 10, a brush holder motor housing 10a, a shaft 11, a core 12, and a commutator 13.
And a brush holder 20 and brushes 21 and 22.

The motor housing 10 includes a permanent magnet 14
Is fixed and supports the shaft 11 press-fitted into the bearings 15 and 16. A core 12 around which a coil is wound is press-fitted and fixed to the shaft 11.
A commutator 13, which is a power supply means, is press-fitted and fixed to the shaft 11. Also, the commutator 13 is the brush 2
It is always sliding with Nos. 1 and 22. Each brush 21,
22 is housed in brush boxes 23, 24 that are fixed to the motor housing 10a and that are integrally formed with the brush holder 20.

FIG. 2 shows a front view from the brush holder 20 side inside the motor. The brush holder 20 is connected to the motor housing 10a by screws 25 and 26. Further, it is electrically connected to the motor housing 10a by a screw 25. The screw 25 is an electrode for ground (hereinafter referred to as GND), and the screw 27 is an electrode for +. 28 and 29 are brush pigtails. The brush 22 and the brush pressing spring 31 are housed in the brush box 24.
The brush pigtail 29 is connected. The screw 25 and one end of the brush pigtail 29 are electrically connected by a brass plate lower plate 33 insert-molded in the brush holder 20. Also, screw 27 and brush pigtail 28
Similarly, one end of is similarly electrically connected by the brass plate lower plate 33.

As shown in FIG. 3, a brass plate lower plate 32
Is insert-molded in the brush holder 20, and the brush pigtail 29 is attached to the brass plate lower plate 32.
And the screw 25 are connected. In addition, the screw 25 causes the brush holder 20 to move to the motor housing 10a.
It is electrically connected. Also, the motor housing 10a
A GND lead wire 35 is connected by a screw 34 provided on the.

A current flows from a lead wire on the + side (not shown), and a current flows from the screw 27 to the brass plate lower plate 33. From the brass plate lower plate 33, through the brush pigtail 28, the brush 21
Flow to. A current flows through the commutator 13 from the brush 21, and a current flows through the brush 22 on the GND side. An electric current flows through the brass plate lower plate 32 via the brush pigtail 29. The current flowing through the brass plate lower plate 32 flows through the screw 25, and then through the motor housing 10a to the screw 34. The current flowing to the screw 34 is the GND lead wire 35.
Flow to.

[0014]

Since the electrode of the brush holder is connected to the motor housing of the conductive member, the ground lead wire and the electrode of the brush holder can be connected via the motor housing, and the brush holder is connected to the motor housing. Since it is not necessary for the connection screw hole and the screw hole of the screw that is provided in the motor housing and that connects the ground lead wire to be a through hole, it is possible to prevent water and the like from entering through the screw hole.

As a result, it is not necessary to dispose a waterproof member for the ground lead wire takeout portion.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an electric motor according to the present invention.

FIG. 2 is a plan view of a brush holder according to the present invention.

3 is a cross-sectional view taken along the line AA shown in FIG.

[Explanation of symbols]

 10a ... Motor housing 11 ... Shaft 12 ... Core 20 ... Brush holder 21, 22 ... Brush 23, 24 ... Brush box 34 ... Screw 35 ... Ground lead wire

Claims (2)

[Claims] 1. In a rectifying type DC motor, a motor housing formed of a conductive member, a brush holder ground electrically connected to the motor housing, and a screw portion provided on the motor housing are connected. An electric motor with an external ground lead. 2. The electric motor according to claim 1, wherein a screw hole for mounting the ground of the brush holder provided in the motor housing and a screw hole for connecting the external ground lead wire are not through holes.