JPH0731101A - Split brush - Google Patents

Abstract

PURPOSE:To obtain a split brush in which excellent commutation characteristics can be attained by damping the vibration of brush quickly and effectively. CONSTITUTION:Upon occurrence of abnormal vibration in a brush body 22, a plurality of split brush arts 24-1, 24-2, arranged slidingly in combination, are slid along the split face 26 thereof. Consequently, the vibration energy is converted into friction heat and dissipated thus damping the abnormal vibration.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a split brush, and more particularly to a split brush capable of reducing brush vibration.

[0002]

2. Description of the Related Art In a DC machine, a brush device and a commutator are used to obtain a rectifying action. The brush device has, for example, a boulder that holds the brush and a spring that elastically presses the brush against the commutator.

However, in such a brush device, the brush vibrates abnormally due to various causes, resulting in defective commutation.
It is known to induce abnormal wear of the brush.
It has been clarified that abnormal vibration of the brush is caused by the existence of several kinds of vibration modes, the inflow of vibration energy due to friction between the brush and the commutator, and the occurrence of self-excited vibration.

As a method for coping with this abnormal vibration, there has been conventionally proposed a technique of applying a lateral pressure to the brush to reduce the vibration by using a lateral pressure leaf spring, a coil spring or the like or a method of inclining the rear end surface of the brush. Proposals have been made (Japanese Utility Model Publication No. 62-188965, Japanese Patent Laid-Open No. 59-66).
734, JP-A-60-31153).

[0005]

However, such a conventional technique has a problem in that it is difficult to obtain a lateral pressure of a magnitude necessary for suppressing abnormal vibration. When a larger lateral pressure is applied, the brush commutator surface is affected. There was a problem that followability deteriorates.

The present invention has been made in view of such conventional problems, and an object thereof is to obtain a split brush that effectively and quickly attenuates brush vibration and obtains good rectifying characteristics. is there.

[0007]

In order to achieve the above object, the split brush of the invention of claim 1 is arranged in contact through a split surface which intersects with the rotating direction of the commutator to form a brush main body as a whole. A plurality of divided brush portions and a holding member that integrally holds the divided brush portions so as to be slidable along the divided surfaces are provided, and the sliding of the divided brush portions attenuates the brush vibration. It is characterized by

According to another aspect of the present invention, there is provided a split brush part, which is disposed in contact with a split surface that intersects the direction of rotation of the commutator, and which forms a brush main body, and a brush holder. By protruding the portion into a leaf spring shape, including a spring portion that partially presses the plurality of divided brush portions, by pressing the spring portion to integrally hold each divided brush portion, It is characterized in that brush vibration is attenuated by sliding of the respective divided brush portions.

The divided brush of the invention of claim 3 is characterized in that the brush main body of the invention of claim 1 or 2 is formed such that the adjacent divided brush portions have different electric resistances.

In this case, it is preferable that the brush main body is formed such that adjacent divided brush portions have different electric resistances.

[0011]

In the split brush according to any one of claims 1 to 3, when abnormal vibration occurs in the brush body, a plurality of split brush portions arranged in combination so as to be in sliding contact with each other are provided along the split surface. It slides and converts vibration energy into friction heat and dissipates it. Thereby, the abnormal vibration is effectively damped and suppressed.

In particular, the split brush according to the second aspect forms the spring portion for pressing the brush main body by projecting a part of the brush holder, so that it can be manufactured inexpensively without increasing the number of parts. it can.

Further, in the divided brush of the third aspect, the electric resistances of the adjacent divided brush portions are different, and the electric resistances of the divided brushes are set so that the upstream side in the rotating direction of the commutator is low and the electrical resistance side is high in the downstream direction. By doing so, most of the rectification can be completed at a relatively early stage of the rectification cycle. Therefore, good rectification characteristics are obtained, and abrupt voltage changes in the latter half of rectification are eliminated.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the drawings.

First Embodiment First, a first embodiment of the present invention will be described by taking a one-way rotating small DC machine as an example.

FIG. 2 schematically shows a commutator 10 used in the DC machine of the embodiment and a brush device 20.

The commutator 10 is provided on the rotor side. The commutator 10 includes a plurality of commutator pieces 12-1 arranged in a ring shape along the rotor rotation direction 100.
12-2, ..., and adjacent commutator pieces 12 are connected by an armature coil (not shown).

The brush device 20 is provided on the stator side. The brush device 20 includes a brush main body 22 that is held by a brush holder (not shown) so as to be in sliding contact with the commutator piece 12, and a pigtail 32 as a power supply line that connects the brush main body 22 and a power source.

The brush main body 22 is formed by using a plurality of divided brush portions 24-1 and 24-2 arranged in contact with each other through a divided surface 26 that intersects the rotation direction 100 of the commutator 10. In the embodiment, the low resistance brush portion 24-1 and the high resistance brush portion 24-2 are arranged in contact with each other through the dividing surface 26 set in the direction orthogonal to the rotation direction 100. Then, each of the divided brush parts 24-1, 24-2
Are slidably connected to each other along the dividing surface 26, and are integrally connected to each other using a coupling fitting 28 as a holding member.

FIG. 3 shows a concrete structure of the brush device 20, and FIG. 3A is a side view thereof and FIG. 3B is a rear view thereof.

As shown in the figure, the brush main body 22 is
The engaging recess 3 is formed on the outer circumference of each of the divided brush portions 24-1 and 24-2.
0 is formed. Then, the fitting fitting 28 is attached and fixed to the engaging recess 30, and both the brush portions 24-1 and 24 are attached.
-2 are integrally connected.

FIG. 4 shows the construction of the coupling fitting 28. FIG. 4A is a side view thereof and FIG. 4B is a plan view thereof.

The connecting fitting 28 of the embodiment is formed in a rectangular cross section with one end open. The fitting 28 is fitted and fixed in the engaging recess 30 of the brush main body 22 from the cutout side. At this time, the fitting 28 is
As shown in FIG. 4, so that the tightening urging force F acts inside,
For example, it is formed by using a leaf spring or the like.

Further, in the embodiment, the connecting fitting 28
The width L1 of the brush is slightly smaller than the width L2 of the engaging recess 30 of the brush main body 22, and the two brush portions 24-1 and 24-2 integrally held by the coupling fitting 28 are shown in FIG. As shown in the drawing, they are slidably formed in a certain range (L2-L1) in the direction of arrow 200.

FIG. 5 shows the operation of the brush device thus formed.

In the conventional device, a plurality of divided brush portions 24-1 and 24-2 are bonded and fixed by the divided surface 26 as shown in FIG.

On the other hand, the brush device 20 of the embodiment is
As shown in FIG. 5, the divided brushes 24-1 and 24-2 are not fixed in contact with each other on the divided surface 26, but are formed so as to slide with a predetermined frictional force.

Therefore, as shown in FIG. 1, even when vibration occurs in the brush main body 22 along the rotor rotating direction 100 during rotor rotation, the divided brushes 24-1 and 24-2 are separated from each other along the divided surface 26. Sliding, and the sliding frictional force at this time converts the vibration energy into friction heat to damp the vibration.

As a result, the vibration generated in the brush body 22 can be effectively damped in a short time. Therefore,
In the brush device 20 of the embodiment, it is possible to effectively suppress rectification failure, abnormal brush wear, abnormal noise, and the like due to abnormal vibration of the brush body 22.

Further, the brush device of the embodiment can effectively suppress not only abnormal vibration but also normal vibration, and exhibit good rectification characteristics with low noise.

Incidentally, the divided brushes 24-1, 24-2.
The frictional force at the time of sliding can be adjusted by the elastic force F of the coupling fitting 28.

Second Embodiment FIG. 7 shows a second preferred embodiment of the present invention.
The members corresponding to those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

The brush device 20 of this embodiment has a triangular prism-shaped low resistance brush portion 24-1 and a high resistance brush portion 24-2.
The brush main body 22 is characterized in that the brush main body 22 is formed by arranging and are slidably combined through the dividing surface 26.

FIG. 8 shows a plan view of the brush main body 22 thus formed, and FIG. 9 shows each divided brush portion 24.
The top view of the coupling metal fitting 28 which connects-holds -1,4-2 is schematically shown.

With the above structure, the vibration generated in the brush main body 22 can be effectively damped, as in the above embodiment.

Third Embodiment FIG. 13 shows a third preferred embodiment of the present invention. FIG. 2 schematically shows a commutator 10 and a brush device 40 used in a DC machine, and FIG.
Corresponding to. The members corresponding to those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

The brush device 40 is provided on the stator side. The brush device 40 includes a brush main body 42 held by a brush holder 46 so as to be in sliding contact with the commutator piece 12, and a pigtail 32 as a power supply line connecting the brush main body 46 and a power source. These structures are basically the same as those of the brush device 20 of the first embodiment.

The brush main body 42 is composed of the commutator 10
It is formed by using a plurality of divided brush portions 44-1 and 44-2 arranged in contact with each other through a divided surface intersecting the rotation direction 100. In the embodiment, the low resistance brush portion 44-1 and the high resistance brush portion 44-2 are arranged in contact with each other through the division surface set in the direction orthogonal to the rotation direction 100. Then, each of the divided brush portions 44-1 and 44-2
Are arranged so as to be slidable along the divided surface, and the divided brush portions 44-1 and 44-2 are pressed by the spring portion 48. The two divided brush parts 44-1 and 44-2 are simply arranged in contact with each other, and the brush main body 42 is integrally formed only by pressing the spring part 48.

The spring portion 48 is formed by the brush holder 46.
Of the divided brush portions 44-1 and 4-4 by partially projecting the two surfaces facing each other.
By pressing each of 4-2 at a position close to the commutator 10, the split brush portions 44-1 and 44-2 slide on the split surface.

FIG. 14 shows an enlarged sectional view taken along the line AA of FIG. As shown in FIG.
Is bent at a position where two spring parts 48 functioning as leaf springs are formed at opposite positions, and the two brush parts 48 divide the split brush parts 44-1 and 44-2.
Is slidably pressed.

Further, the coil spring 50 is provided in the brush main body 42.
By pressing the rear end face, the brush main body 42 is brought into contact with the commutator 10 with an appropriate brush pressure, and the spring constant of the spring portion 48 is determined in consideration of the spring constant of the coil spring 50. It That is, the coil spring 5
When the spring constant of the spring portion 48 is too large as compared with the spring constant of 0, the followability of the brush main body 42 deteriorates. On the other hand, in the opposite case, the sliding resistance between the divided brushes 44-1 and 44-2 becomes too small, and the object of the present invention of converting the vibration energy into friction heat and dissipating it cannot be achieved. Therefore, it is necessary to determine the spring constant of the spring portion 48 so that the followability is good and an appropriate frictional heat is generated.

FIG. 15 shows the operation of the brush device thus formed. This figure corresponds to FIG. 5 of the first embodiment.

As shown in FIG. 15, the split brush 44-
Since 1 and 44-2 are merely pressed by the spring portion 48, they are not fixed in contact with each other on the split surface, but are formed so as to slide with a predetermined frictional force determined by the spring constant of the spring portion 48. . Therefore, even when vibration occurs in the brush main body 42 along the rotor rotation direction 100, the divided brushes 44-1 and 44-2 slide along the divided surfaces,
The sliding frictional force at this time converts the vibration energy into friction heat to damp the vibration.

As a result, similarly to the above-described first and second embodiments, the vibration generated in the brush main body 42 can be effectively damped in a short time, and the rectification failure due to the abnormal vibration of the brush main body 42 is caused. It is possible to effectively suppress the abnormal brush friction and the generation of abnormal noise.

The spring portion 48 formed by bending a part of the brush holder 46 is
When 6 is formed by a metal plate, it can be manufactured at the same time when the brush holder 46 is formed by press working, and when forming the brush holder 46 by resin, it is formed by injection molding.

The present invention is not limited to the above-mentioned embodiment, and various modifications can be made within the scope of the gist of the present invention.

For example, in each of the above embodiments, the brush main body 2
2, 42 are divided into two divided brush portions, but the present invention is not limited to this, and an arbitrary number of divided portions can be selected depending on the desired rectifying characteristics, rectifying rotation direction, required vibration damping capacity, and the like. Any shape can be adopted.

For example, FIG. 18 shows a case where the brush main body of the third embodiment is formed by three layers of divided brush portions 60-1, 60-2, 60-3. In this case, the divided brush parts 60-1, 60-2, 60-3 and the divided brush parts are arranged so that the resistance value increases from the upstream side to the downstream side in the rotating direction of the commutator, and the distance between the divided brush parts is increased. It is slidable.

Further, the dividing surface of each divided brush is not limited to a flat surface, and various surface shapes, for example, curved surface shapes can be adopted if necessary.

For example, as shown in the plan view of FIG. 10, divided brush portions 24-1 and 24-2 having a trapezoidal cross section may be adopted. In this case, the width L of the brush main body 22 in the commutator rotation direction and the length l of each divided brush portion 24 on the short side.
The rectification characteristics can be adjusted by changing the ratio (l / L) of and. In this case (1/20) ≤ (l
/ L) <(1/2) is desirable.

Further, in each of the above-mentioned embodiments, the description has been made by taking the DC machine of the type in which the rotor rotates in one direction as an example, but the present invention is not limited to this, and may be applied to, for example, a bidirectional rotary DC machine. Applicable.

11 and 12 schematically show plan views of specific examples of the brush main body 22 used in the bidirectional rotating DC machine.

The brush body 22 shown in FIG. 11 is formed by arranging a low resistance brush portion 24-1 in the center and high resistance brush portions 24-2, 24-2 on both sides thereof. In addition,
The brush portions 24-1 and 24-2 are slidably connected along the dividing surface 26, as in the above-described embodiment.

The brush main body 22 shown in FIG. 12 is formed by providing a high resistance brush portion 24-2 at the center and arranging low resistance brush portions 24-1 and 24-1 on both sides thereof.

As shown in FIGS. 11 and 12, the brush main body 2
By forming 2 symmetrically in the figure, the same rectifying characteristic can be always exhibited even if the rotation direction of the commutator 10 changes.

Further, in the above-described third embodiment, the two spring portions 48 are formed by using a part of the brush holder 46, but one of the spring portions 48 may be omitted. .

FIG. 16 shows the structure of the brush device in which one of the two spring portions 48 is replaced with the protrusion 54.
Even in this case, the brush main body 42 is pressed by the spring portion 48 and the protrusion 54, so that the divided brush portions 44-1 and 44-2 forming the brush main body 42 can slide on the divided surfaces. The same effect as when the two spring portions 48 are provided can be obtained.

Further, although the divided brush portions 44-1 and 44-2 having the rectangular cross section are considered in the above-mentioned third embodiment,
It is also possible to form each divided brush portion into a triangular prism shape as in the second embodiment.

FIG. 17 shows a case where a brush main body is formed by slidably combining a low-resistance brush 56-1 and a high-resistance brush 56-2 each having a triangular prism shape via a dividing surface. . 13 is an enlarged cross-sectional view taken along line BB of FIG. 13, in which the low resistance brush 56-1 is located on the upstream side in the rotation direction 100 of the commutator 10 and the high resistance brush 56- is located on the downstream side.
2 are arranged respectively. The two protrusions 58 shown in the figure are for preventing the low resistance brush 56-1 and the high resistance brush 56-2, which are pressed by the spring portion 48, from slipping sideways.

Further, in each of the above-described embodiments, the case where the plurality of divided brush portions having different resistance values are slidably arranged to form the brush main body has been described, but the plurality of divided portions having the same resistance value are described. The brush portion may be slidably arranged. Even in this case, there is an effect that the vibration energy can be converted into frictional heat by sliding to damp the vibration.

In each of the above embodiments, the case where the present invention is applied to a DC machine has been described as an example, but it goes without saying that the present invention is not limited to this and can be applied to other rotary electric machines. Nor.

[0062]

As described above, according to the inventions of claims 1 to 3, the vibration generated in the brush main body, especially the abnormal vibration, can be effectively damped in a short time.

In particular, according to the second aspect of the present invention, since the spring portion for pressing the brush main body is formed by projecting a part of the brush holder, it can be manufactured inexpensively without increasing the number of parts. You can

Further, according to the invention of claim 3, the electric resistances of the adjacent divided brush portions are different, and the electric resistances of the divided brush portions are set to be low on the upstream side in the rotational direction of the commutator and high on the downstream side. By setting, most of the rectification can be ended at a relatively early stage of the rectification cycle. Therefore, good rectification characteristics are obtained, and abrupt voltage changes in the latter half of rectification are eliminated.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an operation of a split brush according to an embodiment.

FIG. 2 is a schematic explanatory diagram of a main part of a DC machine to which the brush device of the present invention is applied.

FIG. 3 is an explanatory diagram of a split brush according to an embodiment.

FIG. 4 is an explanatory view of a connecting fitting used in the split brush of the embodiment.

FIG. 5 is an explanatory diagram showing the operation of the split brush of the embodiment.

FIG. 6 is a schematic explanatory view showing a configuration of a conventional split brush.

FIG. 7 is a schematic perspective explanatory view of another embodiment of the split brush of the present invention.

8 is a schematic plan view of the split brush shown in FIG. 7. FIG.

9 is a plan explanatory view of a coupling fitting used in the split brush shown in FIG. 7. FIG.

FIG. 10 is an explanatory plan view of another embodiment of the split brush of the present invention.

FIG. 11 is a plan view of a split brush used in a bidirectional rotary electric machine.

FIG. 12 is a plan view of another embodiment of the split brush used in the bidirectional rotary electric machine.

FIG. 13 is a schematic explanatory diagram of a main part of a DC machine to which a brush device according to another embodiment of the present invention is applied.

14 is an enlarged cross-sectional view taken along the line AA of FIG.

FIG. 15 is an explanatory diagram showing the operation of the split brush of another embodiment.

FIG. 16 is a cross-sectional view of a brush device having one spring portion.

FIG. 17 is a cross-sectional view of a brush device according to another embodiment of the present invention.

FIG. 18 is a sectional view of a three-layer brush device according to another embodiment.

[Explanation of symbols]

22, 42 Brush main body 24-1, 24-2, 44-1 and 44-2 Divided brush portion 26 Divided surface 28 Coupling metal fitting 30 Engagement concave portion 46 Brush holder 48 Spring portion

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiromi Suzuki 390 Umeda, Kosai City, Shizuoka Prefecture Asmo Stock Company In-house (72) Inventor Yoji Hino 390 Umeda, Kosai City, Shizuoka Prefecture In-house (72) Inventor Nakamura Toshiaki 390 Umeda, Kosai City, Shizuoka Prefecture Asmo Stock Association In-house (72) Inventor Takio Oya 2-27-2 Sakainancho, Musashino City, Tokyo

Claims (3)

[Claims] 1. A plurality of divided brush portions, which are arranged in contact with each other through divided surfaces that intersect with the rotation direction of the commutator and form a brush main body as a whole, and each of the divided brushes are slidable along the divided surfaces. And a holding member for integrally holding the brush portion, wherein the divided brush portion slides to damp the brush vibration. 2. A plurality of split brush portions, which are arranged in contact with each other through split surfaces intersecting with the rotating direction of the commutator and form a brush main body as a whole, and a part of a brush holder is projected in a leaf spring shape. A spring part that partially presses the plurality of divided brush parts, and by integrally holding the divided brush parts by pressing the spring parts, the brushes can be slid by the divided brush parts. Divided brush characterized by damping vibration. 3. The divided brush according to claim 1, wherein the brush main body is formed so that adjacent divided brush portions have different electric resistances.