JPS5929354Y2 - brush device - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a brush device having a rotating electrode, such as a commutator of an electric drill using a commutator motor, and a brush that is pressed into contact with the rotating electrode.

A conventionally known brush device of this type will be explained with reference to FIG.

In the figure, 1 is an armature that constitutes a part of a commutator motor for an electric drill, 1a is a rotating electrode consisting of a commutator that is a part of armature 1, and 2 houses the armature 1, rotating electrode 1a, etc. A frame body 2a includes a through hole 3 formed in a portion of the frame body 20 facing the rotating electrode and communicating the inside and outside of the frame body 2.
4 is a bearing that is supported by the frame 2 and rotatably supports the armature 1, and 4 is a brush guide that is press-fitted into the hole 2a of the frame 2 and guides the movement of the brush, which will be described later. It is composed of an electrode 5 and an insulator 6 attached to the outer circumference thereof and having a screw hole 6a formed at the end opposite to the rotating electrode 1a side,
A portion of the electrode 5 is connected to a power cord (not shown).

γ is a brush movably inserted into the hole 5a, 8 is a first elastic body made of a compression coil spring that engages with the brush 7 and brings one end of the brush 7 into pressure contact with the rotating electrode 1a, and 9 is a first elastic body. 1 is a receiver made of a conductive material 2 that comes into contact with the end of the elastic body 8 opposite to the brush γ side; 10 is a lead wire that electrically connects the brush 7 and the receiver 9; 11 is an insulator 6; screw hole 6a
This is a stopper that is screwed onto the hole 5a, and is used to bring the electrode 5 and the receiver 9 into pressure contact and to prevent the brush 7, first elastic body 8, etc. inserted into the hole 5a from falling out.

The button configured in this way has the following features: When power is supplied to the rotating electrode 1a through the power cord, the electrode 5, the receiver 9, the lead wire 10, and the brush 7, the armature 1 rotates, and the brush 7 As is well known, when the brush 7 is worn out, the elasticity of the first elastic body 8 causes the brush 7 to move toward the rotating electrode 1a.

However, when the brush device vibrates due to the rotation of the armature 1, etc., the stopper 11 screwed into the screw hole 6a rotates extremely easily, and the pressure contact between the rotating electrode 1a and the brush 7, and between the electrode 5 and the holder 9 becomes unstable. Because of this, not only is it not possible to stably supply the electric power to the rotating electrode 5, but the stopper 11, the brush 7, etc. eventually fall off, and there are many cases where the stopper 11, etc. is lost. .

This invention was made in view of the conventional situation as described above, and is intended to suppress the rotation of the stopper 110 due to vibration and to stably supply the above-mentioned power to the rotating electrode 5.
The purpose of this invention is to provide a brush device which is designed to prevent the brush from falling out of the brush guide 4. An embodiment of this invention will be described below with reference to FIG.

In the figure, reference numeral 13 denotes a second elastic body made of a spring steel plate, which is attached to the outer surface of the frame 21 with screws 14 so that one end thereof comes into pressure contact with the stopper 11.

The explanation of the other symbols is the same as the explanation of the symbols in FIG. 1, so the explanation will be omitted.

In the structure configured in this way, the second elastic body 13
is attached to the frame 12, and one end thereof is attached to the stopper 11.
Since the stopper 11 is in pressure contact with the stopper 11, rotation of the stopper 11 due to vibration is suppressed.

Note that the position of attaching the second elastic body 130 to the frame body 12 is not particularly limited.

Furthermore, there are no particular limitations on the mutual positional relationship of the stopper 11 and the second elastic body in terms of pressure contact.

As mentioned above, this design press-fits the brush guide into the through-hole of the frame, so it will not move and wear even if the frame vibrates, and the stopper is screwed into the screw hole of the brush guide. Since the brush is pressed by a plate-like elastic body, it is possible to prevent the stopper from falling off due to vibration of the frame, and furthermore, the brush can be easily replaced by removing the stopper.

Furthermore, according to this invention, the second elastic body is attached to the housing and the second elastic body is brought into pressure contact with the stopper, so that the dimensional accuracy of the housing, stopper, etc. is limited. At worst, the stopper and the second elastic body can be engaged with each other within the restorable range of the second elastic body, which is extremely valuable in practical terms.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view of a conventional brush device, and FIG. 2 is a partial sectional view of an embodiment of this invention. In the figure, 1a is a rotating electrode, 2a is a through hole, γ is a brush, 8 is a first elastic body, and 11 is a stopper 13 is a second elastic body. Note that the same reference numerals in the figures indicate the same, different, or equivalent parts.

Claims (1)

[Scope of utility model registration request] A brush guide that is press-fitted into a through-hole of a frame and has a screw hole at its outer end; a brush inserted into the inner end of this brush guide;
A receiver that is inserted into the brush guide and presses the brush via the first elastic body; a stopper that is screwed into the threaded hole of the brush guide to fix the receiver; one end is fixed to the frame; and a second plate-shaped plate whose other end presses the stopper.
Brush device with elastic body.