JP2580435Y2 - Brush holding device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brush holding device for a DC machine, and more particularly to a technique for preventing a brush box from being deformed.

[0002]

2. Description of the Related Art As a brush holding device used in a DC motor, a brush box into which a brush is slidably inserted is formed integrally with a base for fixing the brush box using resin. A cap is mounted on one end of the brush box so as to close the cap, and the cap is configured to receive the reaction force of the brush spring to slide the brush against the commutator.

[0003]

In such a brush holding device, since the side wall of the brush box formed of resin is likely to fall inward due to heat, the brush tends to be difficult to slide.

That is, since both the base and the brush box are molded using a thermoplastic resin such as nylon resin, when the temperature of the brush increases, the contact surface of the brush box with the brush deforms, The slidability becomes worse.

Further, if the base and the brush box are integrally formed, burrs are generated on the opening end side of the brush box due to the mold splitting, and the slidability of the brush may be hindered.

[0006] An object of the present invention is to provide a brush holding device that can prevent the occurrence of poor sliding of a brush.

[0007]

Brush holding device according to the present invention SUMMARY OF THE INVENTION The brush box ends is formed in the opened rectangular tube shape hollow portion in the cylinder forms a housing part (5) and (4) Before
Serial receiving portion and the front end portion accommodating portion (5) (5) brushes arranged so as to protrude from the front end opening is slidably fitted in the cylinder axis direction of the (1), the brush (1) Pigtail
(2) and is inserted the brush box (4) pigtail insertion hole that is opened so as to open at one end extending in the cylinder axis direction in one side wall (6), a rear end of the brush box (4) the receiving portion and the cap are capped so as to close the (5) (10), housed prior Symbol brush into said receiving portion (5) to the rear end comes into contact with the cap (10)
(1) comprises a brush spring (9) which biases the commutator (16) and, in the brush holding device the brush box (4) is fixed to the resin base (3), said base (3) Insert the brush box (4)
There is an opening (7) that can enter
A pair of radially outer ends opened on both side surfaces of the opening (7)
Stopper grooves (8) and (8) are formed respectively.
And the brush box (4) is molded using a heat-resistant resin.
The brush box (4) has a pair of
The stoppers (15) are formed so as to protrude, respectively.
The brush box (4) is inserted into the opening (7) from the outer end.
The two stoppers (15) and (15) are the two stopper grooves.
(8) and (8) are fitted and fixed respectively.
And features.

[0008]

According to the above-described means, the brush box is formed separately from the base, and the brush box is formed using a heat-resistant resin. Deformation is suppressed. As a result, it is possible to suppress an increase in the contact resistance between the brush and the brush of the brush box as the temperature of the brush increases. Also, the stopper
Since it is located at the bottom of the side of the brush box, the opening of the base
Brush box with the brush box fixed to the part
The part where the brush slides in does not deform,
The brush can slide stably.

[0009]

FIG. 1 is an exploded perspective view showing a brush holding device according to an embodiment of the present invention, and FIG. 2 is a partially omitted front sectional view in an assembled state.

In the present embodiment, the brush holding device according to the present invention has a pair of brush boxes 4 for holding the brush 1 on which the pigtails 2 are implanted (only one of them is shown; other components are shown). The brush box 4 is removably mounted on a base 3 for fixing the brush holding device to a DC motor or the like. Since the other components including the brush box 4 are formed symmetrically with respect to the center, only one of the components will be representatively described.

The base 3 is made of a nylon resin, which is an example of a thermoplastic resin, and is integrally formed in a circular ring shape so as to surround the commutator 16. A brush box 4 is removably inserted into the base 3. Openings 7 are arranged so as to face each other in the diametric direction,
It is formed in a groove shape having a constant width and a constant depth, which is open at both ends in the radial direction and an upper surface. Further, a pair of stopper grooves 8 are provided on both side walls of the opening 7 so as to extend radially toward the bottom of the base 3. A pair of engaging portions 12 for engaging with a retaining claw of a cap to be described later is formed in a pair of bulging portions in an outer position on an upper surface of the base 3 adjacent to the opening portion 7. .

On the other hand, the brush box 4 is made of a heat-resistant resin such as a phenolic resin and formed of a thermosetting resin, and has a substantially square shape with both ends (hereinafter referred to as front and rear ends) opened. Is formed in the shape of a square tube. A brush 1 having a shape substantially the same as the inner diameter of the brush box 4 is provided in a housing portion 5 formed by a hollow portion of the brush box 4 so that the front end can protrude from a front end opening, and slides in the front-rear direction. It is freely inserted.

A pigtail insertion hole 6 is formed in the upper wall of the brush box 4 to be elongated in the front-rear direction at the center. The pigtail 2 implanted in the brush 1 is slidably inserted into the insertion hole 6. Have been. A pair of stoppers 15 that can be fitted into the stopper grooves 8 are arranged on both side walls of the brush box 4 so as to extend in the front-rear direction at the bottom, and are formed so as to bulge.

A cap 10 closes a rear end opening at the rear end of the brush box 4 configured as described above.
It is mounted so as to be able to receive the reaction force of the brush spring 9 housed in the housing part 5. The cap 10 is formed integrally using a normal resin such as a nylon resin, and is formed in a rectangular flat plate shape larger than the outer shape of the end face of the brush box 4. A brush spring positioning projection 11 is provided on the cap 10 at a substantially central portion of an end face facing the brush box side, and is integrally protruded therefrom. The brush spring 9 is concentrically disposed on the projection 11. Are positioned.

The cap 10 has a pair of retaining pieces 13 disposed substantially at the center of the left and right sides, respectively.
Projections are integrally formed so as to extend in a forward direction in a state parallel to each other, and engaging claws 14 are respectively formed to protrude inward at distal ends of the both retaining pieces 13, 13. Then, in a state where the cap 10 is attached to the brush box 4,
Each engaging claw 14 of each of the retaining pieces 13, 13 is engaged with each engaging portion 1.
2 , 12 respectively. As a result, the cap 10 is attached to the rear end of the brush box 4 in a state where the cap 10 does not come off. Therefore, the cap 10 receives the reaction force of the brush spring 9 and urges the brush 5 forward, thereby bringing the brush 5 into sliding contact with the commutator 16 under a predetermined elastic force.

When this brush holding device is used in a rotating electric machine and the brush holding device is fixed to the yoke 17, the cap 10 comes into contact with the outer surface of the cap 10 in contact with the yoke 17, thereby supporting the back side. It has become so. Therefore, the brush box 4 can be securely fixed to the base 3 by the cap 10.

Next, a description will be given of the function of the brush holding device according to the above-described configuration to prevent the deformation of the brush box.

The base 3 and the brush box 4 made of resin expand and contract, respectively, due to the temperature cycle accompanying the heat generation of the DC motor. Moreover,
Since the brush 1 is inserted into the brush box 4, the brush 1 is affected by the temperature rise of the brush 1.

However, in this embodiment, the brush box 4
Is molded separately from the base 3, and the base 3 is molded from a thermoplastic nylon resin, whereas the brush box 4 is molded from a thermosetting phenolic resin. The deformation of the brush box 4 is suppressed more than the deformation of the base 3. Therefore, the contact surface of the brush box 4 with the brush 1 is prevented from being deformed, and the slidability of the brush 1 is prevented from being deteriorated.

[0020]

[Effects of the Invention] As described above, according to the present invention,
The base and the brush box are each configured separately,
Moreover, the brush box is integrally molded from heat-resistant resin,
Since the brush box is detachably attached to the base, it is possible to prevent the contact surface of the brush box with the brush from being deformed due to the temperature rise of the brush, and to prevent the slidability of the brush from being reduced. be able to. In addition, stopper
Since it is located at the bottom of the side of the box, the opening of the base
To the brush box with the brush box fixed
The sliding part of the brush is not deformed.
The brush can slide stably.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a brush holding device according to an embodiment of the present invention.

FIG. 2 is a partially omitted front sectional view in an assembled state.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Brush, 2 ... Pigtail, 3 ... Base, 4 ... Brush box, 5 ... Housing part , 6 ... Pigtail insertion hole, 7 ... Opening,
8: stopper groove, 9: brush spring, 10: cap, 11: brush spring positioning projection, 12: engaging part, 13: retaining piece, 14: engaging claw, 15: stopper, 16: commutator, 17 ... yoke.

Claims (1)

(57) [Scope of request for utility model registration] 1. A two ends is formed in the opened square tubular
Brush box empty portion in the cylinder forms accommodating portion (5) (4)
When the housing section and the front end portion accommodating portion (5) brushes arranged so as to protrude from the front end opening is slidably fitted in the cylinder axis direction (5) (1), said brush (1 pigtail (2) the brush box is inserted (pigtail insertion hole is opened so as to open at one end extending in the cylinder axis direction in one side wall of 4) (6), the brush box) (4)
The receiving portion at the rear end of the (5) a cap that is capped so as to close the (10), the rear end is the cap (10)
The receiving portion so as to abut on the (5) is accommodated before Symbol brush (1) and a commutator brush spring (9) which biases the (16), said brush boxes (4)
Is fixed to a resin base (3) , wherein the brush box (4) can be inserted into the base (3).
The opening (7) is opened and this opening
(7) A pair of strikes whose radial outer ends are open on both side surfaces
The brush box (4) is formed by using a heat-resistant resin.
The brush box (4) has a pair of brushes at the bottom on both sides.
The toppers (15) are respectively formed to bulge, and the brush box (4) is inserted into the opening (7) from an outer end.
The two stoppers (15) and (15) are the two stopper grooves.
(8) and (8) are fitted and fixed respectively.
And a brush holding device.