JPS6318946A - Motor - Google Patents

Abstract

PURPOSE:To obtain an improved electrical contact with simple composition, by forming a brush arm to be rigid, and by supporting an arm engaging section at the brush arm rotatably against an arm guide. CONSTITUTION:A motor terminal is composed of an arm guide 12 penetrating through a case cover 4, and current is supplied to a brush arm 8 via a contact point between an arm engaging section 15 and the arm guide 12. The brush arm 8 is essentially formed to have rigidity, and when the brush arm 8 is urged by a spring 14, the surface of a commutator 5 is pressed by a carbon brush 10. In this case, the arm engaging section 15 at the brush arm 8 is rotatably supported against the arm guide 12, and even if the carbon brush 10 is abraded, it comes in correct contact with the commutator 5 and is contrived to slide on the surface of the commutator 5.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a motor, particularly a motor configured by engaging a motor case that holds a field and a case lid that mounts a brush device. The present invention relates to a motor in which a brush arm holding a brush is made substantially rigid to prevent undesired sawing motion of the brush and also to prevent an increase in contact resistance when energizing the brush arm.

[Conventional technology]

Fig. 8 shows a longitudinal cross-sectional view of a conventional motor, and Fig. 9 shows a brush device mounted on the case lid.
A cross-sectional view taken along the -x' line is shown.

Conventional motors generally have configurations as shown in FIGS. 8 and 9. In the figure, 1 is a cylindrical motor case, 2 is a field made of permanent magnets, 3 is a rotor, 4 is a case lid, 5 is a commutator, 6 is a rotating shaft, 7 is a bearing, and 8 is a brush. Arm, 9 is motor terminal, 10! i carbon brush.

11 represents an arm fixing part.

In the illustrated case, the brush arm 8 is made of a flexible plate and holds a carbon brush 10 near its tip, and the other end is fixed to the case M4 at an arm fixing part 11. The brush arm 8 is integrally formed with a motor terminal 9 shown in FIG.
is engaged with the open end of motor case 1.

The brush arm 8 is expanded from the dotted line position shown in FIG. 9 to the solid line position so that the carbon brush 10 can slide over the commutator.

[Problem that the invention seeks to solve]

The conventional configuration described above also uses carbon brushes and is suitable for relatively high output motors, but this is the case when an even higher output is desired.

There are the following problems. That is.

(A) A flexible brush arm 8 is used as shown in FIG. This is used because the structure for mounting the brush device on the case lid 4 is simple and is preferred as a mass production technique.

However, as shown in FIG. 9, the brush arm 8 is in a curved state and presses the carbon brush 10 against the surface of the commutator 5. The rotor rotates under this condition, but if the commutator 5 were to rotate counterclockwise in the condition shown in FIG.
The carbon fiber is first stretched as shown by arrow a in the figure.
The brush 10 is moved, and when the extension of the brush arm 8 reaches its limit, the brush 10 is moved one time so as to return to its original position as shown by the arrow in the figure. That is, the carbon brush 10 makes a so-called sawtooth movement on the surface of the commutator 5, as shown by arrows a and b in the figure. Therefore, undesired sparks are generated along with the sawing motion, which becomes a major hindrance to increasing the output of the motor.

(B) In order to solve the problems mentioned in paragraph (A) above,
Instead of the above-mentioned flexible brush arm 8, the arm itself is substantially rigid, and the rigid arm is pressed by a separately provided spring body to move the carbon brush 10 against the surface of the commutator 5. Pressing upwards is considered. However, in this case, electricity is supplied through the spring body. For this reason, the spring body has the function of pressing the carbon brush 10 onto the surface of the commutator 5 and the function of energizing the brush arm.

The material of the spring body is an issue.

(C) In order to also overcome the problem mentioned in paragraph (B) above,
The above-mentioned spring body mainly has the above-mentioned pressing function,
It is considered that a non-rigid conductive lead in the form of a pigtail is connected to the rigid arm and the rigid arm is energized through the conductive lead. In this case.

Although the problems mentioned in (A) and (B) above are solved, it is necessary to connect the conductive leads, which requires work such as soldering, which is not necessarily desirable from a mass production technology standpoint. do not have.

(D) In order to solve the problems listed in (A> or C) above, one end of the rigid brush arm is held rotatably relative to the two cylindrical conductive arm guides. Provide an arm locking part. Then, it is considered that the brush arm is energized through the arm locking portion and the brush arm is pressed by the spring body. However, in the case of this configuration, electrical contact between the arm locking portion and the arm guide becomes a problem. In other words, electricity is supplied through a point where one side rotates relative to the other, and electrical contact becomes a problem.

[Means for solving problems]

The present invention solves the above-mentioned problems, and is designed to simplify the structure for attaching the above-mentioned spring body.

FIG. 1 shows the configuration of a main part which also serves as an embodiment of the present invention. In the figure, 4 is a case lid, 5 is a commutator, 7 is a bearing, 8 is a brush arm, 10 is a carbon brush, 1
Reference numeral 2 represents an arm guide, 13 a spring receiver, 14 a spring, and 15 an arm locking portion.

In the conventional case (FIG. 9), the case lid 4 as shown in FIG. 1 is engaged with the motor case 1 as shown in FIG.
is the same as

In the case shown in FIG. 1, the brush arm 8 is substantially rigid and holds a carbon brush 10 near its tip;
An arm locking portion 15 is provided at the other end. A conductive column is provided on the case lid 4 and constitutes an arm guide 12. The arm locking portion 15 is substantially the same as shown in FIG.

It has a hollow cylindrical shape that encloses the arm guide I2, and as will be described in detail later with reference to FIGS. In terms of shape, they touch at two points, so to speak. That is, when the arm locking part 15 is rotatably supported with respect to the arm guide 12, there is a gap between the arm guide 12 and the arm locking part 15.
Even if conditions arise that may cause ``rattle''.

Spring 14 connects arm locking portion 15 to arm guide 1
2, and always keep the arm/locking part 15 and the arm-
Care has been taken to ensure proper contact with the guide I2. In order to obtain a large pressing force at this time, the position where the spring 14 presses the brush arm 8 can be selected as close to the arm guide 12 as possible.

The spring 14 is held at one end by a spring receiver 13 that is at substantially the same potential as the arm guide 12, and presses the brush arm 8 at the other end.
One end of the brush arm 8 may be held by the brush arm 8, and the other end may press against the spring receiver 13.

[Effect]

The motor terminal is constituted by an arm guide 12 provided through the case M4, and the brush arm 8 is energized through the contact point between the arm locking portion 15 and the arm guide 12. The brush arm 8 is formed to be substantially rigid, and the carbon brush 10 presses against the surface of the commutator 5 as the plan arm 8 is pressed by the spring 14. At this time, the arm locking portion 15 of the brush arm 8 is rotatably supported with respect to the arm guide 12, and even if the carbon brush 10 is worn, it can properly contact the commutator 5 and maintain the surface of the commutator 5. is made to slide. Note that there is a route for energizing the brush arm 8 from the arm guide 12 through the spring receiver 13 and via the spring 14;
Needless to say, electricity is supplied mainly through the arm locking portion 15, although it has a similar shape. Also, as much as possible, even if the carbon brush 10 shown in FIG. In addition, the strength of the spring and the position of the spring relative to the brush arm 8 can be selected.

〔Example〕

FIG. 2 is a detailed view of the contact portion between the arm guide and the arm locking portion, and FIG. 3 is an enlarged view of the main part thereof. Also the fourth
The figures through FIG. 6 each show a modification of the configuration shown in FIG. 1. Furthermore, FIGS. 7(A), 7(B), and 7(C) each show how the brush device is arranged with respect to the case lid.

In FIGS. 2 and 3, reference numeral 4. 9. 12.
15 correspond to FIG. 1 and FIG. 8, respectively. Also 1
2a is an annular convex portion provided on the arm guide 12, and 16 represents a tangential portion provided on the arm locking portion 15 according to the present invention.

Further, reference numeral 17 represents a screw.

Figure 3 (A) and (B) are A - in the case shown in Figure 2.
This corresponds to the enlarged cross-sectional views of line A and line B-B 6m, respectively.

The arm locking portion 15 is a portion of the arm guide 12 that is in contact with the annular protrusion 12a.

The illustrated tangent portion 16 is formed. That is, FIG. 3(A)
When considering the cross section as shown in the figure, the annular protrusion 12
It is made to have a tangent part 16°16 that is tangent to the circle formed by a. The tangents 16.16 are chosen to intersect each other, for example at 30°.

For this reason, as can be seen from consideration of FIG. 1, when the brush arm 8 is pressed by the spring 14, the tangential portion 16. 16 is always in contact with the annular protrusion 12a on the arm guide (see Fig. 3 (A)).
,) When a cross section is taken as shown in the figure, the shape is so to speak two points in contact) 6 In the present invention, the annular protrusion 12a may not exist (in this case, the shape shown in the cross section) This is a two-point contact, but overall it is creating two line contacts). Also, instead of providing an annular protrusion 12a on the arm guide 12, a protrusion 12b protruding toward the arm guide 12 is provided on the arm locking portion 15 side as shown in FIG. 16.16 may be formed.

Further, the tangential portion 16.16 does not necessarily have to have a straight line shape, and a part of the arcuate portion may be in contact with an arcuate portion having a diameter larger than the circular arc of the annular protrusion portion 12a. Good too.

Further, the cross-sectional shape of the arm guide 12 is not necessarily limited to a circular shape, but may be any shape as long as the cross section of the annular protrusion 12a and the tangent portion 16.16 are in contact at two points.

In the present invention, as shown in FIG. 3(A), a typical configuration has a tangential portion 16, 16 at least in cross-sectional view, so that the above-mentioned two-point contact occurs, and the spring 14 is used to properly This allows for two-point contact. That is, the arm locking portion 15 is pressed by the arm guide X2 as indicated by the arrow P in FIG. 3(A), and there is no risk of electrical contact failure, and stable rotation as a motor can be obtained.

Reference numeral 4 in FIGS. 4(A) and (B). 5. 7. 8゜1
0.12, 13.1.4.15 correspond to FIG. In the configuration shown in FIG. 4(A), the arm guide 12 is, unlike the cases shown in FIGS. 2 and 3, properly configured in a cylindrical shape. As shown in an enlarged view of the main part in FIG. , the arm guide 12 is provided with a hole through which the spring 14 acts to make two-point contact similar to that described with reference to FIGS. 2 and 3. Also, spring 14.

It is provided so as to wrap around the arm guide 12, and the arm
The brush arm 8 is pressed against the guide 12.

Numbers 4, 5, 8, 10, 12, 13.14 shown in Figure 5
．． 15 corresponds to FIG. In the illustrated case, the contact mode between the arm guide 12 and the arm locking portion 15 is the first one.
In the case illustrated (therefore.

This is similar to the case shown in FIG. 2 and FIG. 3, but the spring 14 is configured in the shape of a helical spring.

Reference numeral 4 shown in Figure 6. 5. 8. 10. 12.
13.14.15 correspond to FIG. and.

The difference from the case shown in FIG. 5 is that the spring 14 is given a force that tends to expand.

Note that these configurations are not limited to those shown in the embodiments. For example, the spring 14 acting on the brush arm 8 shown in FIG. 4 may be the spring 14 and spring receiver shown in FIGS. Of course, it is also possible to use one having a structure of 13.

FIGS. 7(A,) to C) each show the manner in which the brush devices are arranged. In the figure, numeral 4 represents a case lid, 5 represents a commutator, and 8 represents a brush arm.

〔Effect of the invention〕

As explained above, according to the present invention, the brush arm 8
The brush has rigidity, so to speak, and the brush does not make undesired sawing movements as in the conventional case. The material of the brush arm should be designed primarily with conductivity in mind, and the material of the spring should be designed primarily to provide the original spring force, although conductivity should also be considered. In addition, because the brush arm 8 has rigidity and the brush arm needs to rotate relative to the arm guide to cope with brush wear, the arm guide and brush
Electrical contact with the arm can be an issue, but this is also correctly addressed.

Furthermore, the structure for holding the spring is relatively simple.

Energization via the spring is also an auxiliary im electricity route.
becomes.

[Brief explanation of drawings]

Fig. 1 shows the configuration of main parts that also serves as an embodiment of the present invention, and Fig.
The figure is a detailed view of the contact part between the arm guide and the arm locking part, FIG. 3 is an enlarged view of the main part, and FIGS. 4 to 6 are modifications of the configuration shown in FIG. 1, respectively. 7(A), 7(B), and 7(C) respectively show how the brush device is arranged with respect to the case lid, FIGS. 8 and 9 show the conventional configuration, and FIG. 10 shows the arrangement shown in FIG. A modification of what is shown is shown. In the figure, 1 is the motor case, and 2 is the permanent magnet field. 3 is a rotor, 4 is a case lid, 5 is a commutator, 8 is a brush.
Arm, 9 is motor terminal, 10 is carbon brush, 1
Reference numeral 2 represents an arm guide, 13 a spring receiver, 14 a spring, and 15 an arm locking portion. Patent applicant Mabuna Motor Co., Ltd. Agent
Patent Attorney Mori 1) Hiroshi (2 others) Fan 1 m Sword 2 Nagi Taka 4 m FA+ +B)
(C) 7th Sword to FiJ - Shibu Otsu

Claims (1)

[Scope of Claims] A motor case that holds a magnetic field is provided, and a case lid that is configured to engage with an open end of the motor case, and a brush device that slides a commutator is connected to the case lid. In the motor, the brush device is mounted on the case and is arranged so that the brushes in the brush device slide on the commutator when the motor case and the case lid are engaged. An arm guide provided on the lid, a brush that slides on the commutator, and a brush arm that holds the brush near its tip and whose other end is rotatably held with respect to the arm guide. The arm portion of the brush arm is configured to have substantially rigidity, and an arm locking portion rotatably held by the arm guide of the brush arm is connected to the arm guide and the arm guide. In the cross-sectional shape of the contact portion with the arm locking portion, the brush arm has two tangent lines that extend in a direction tangent to the cross-section of the arm guide and intersect with each other, and the brush arm contacts the cross-section of the arm guide. and a spring receiver that is electrically connected to the motor terminal through a contact point with the cut-off wire portion of the arm locking portion and placed in electrical continuity with the arm guide; A motor comprising a spring having one end in contact with the spring receiver and the other end in contact with the brush arm.