JP3815632B2 - Brush for small motor - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a brush motor. More specifically, the present invention relates to a compact, lightweight, easy-to-manufacture, and durable small motor with excellent portability that is used in vibration alarm devices and the like.
[0002]
[Prior art and its problems]
In recent years, attention has been paid to a pager device using a vibration method instead of a ringing method using sound, and improvements have been made to motor devices that generate vibrations.
As this motor device, for example, a hollow cylindrical coreless motor device shown in FIG. 5 is known. This apparatus has a rotor comprising a cylindrical coil 1, a cylindrical coil support 2, a commutator 3 formed on the support, and a rotating shaft 4 that passes through the center of the support and is fixed to the support. The rotating shaft 4 of the rotor is inserted into a hollow cylindrical field magnet 5 and is disposed on one end side in the cylindrical housing case 6 and on the other end side of the housing case 6. The bearing 8 is supported.
[0003]
Normally, in the coreless motor device having this structure, an eccentric weight 10 having a biased center of gravity is provided at the tip of the rotating shaft 4, and the commutator 3 is in contact with the brush 9 on the stator side. The housing case 6 is fixed to a holder in a case such as a pager, and the eccentric weight 10 is rotated to transmit this vibration to the pager body via the housing case 6 so that the function as a vibration pager is exhibited.
[0004]
As a brush device of such a small brush motor, a straight spring-like ribbon wire 31 serving also as a contact material fixed to a brush holder 33 is used as shown in FIG. However, when the motor becomes smaller, the effective length of the spring becomes insufficient, and it has been impossible to contact the commutator 3 with a predetermined preload.
[0005]
Therefore, as shown in FIG. 4, a U-curved ribbon line 41 obtained by bending the ribbon line into a U-shape has been used. However, when the motor is further reduced in size and diameter, the effective length of the spring becomes insufficient even in the shape shown in FIG. 4, and thus a stable spring pressure cannot be obtained.
[0006]
The present invention has been made in view of the circumstances as described above, and it is an object of the present invention to improve the drawbacks of conventional devices and to provide a brush for a small motor that can obtain a stable spring pressure even with a very small diameter. It is said.
[0007]
[Means for Solving the Problems]
The present invention has been made to solve the problems of the prior art, and will be described with reference to FIG. 1 and FIG. 2 corresponding to the embodiment. The small motor melt brush according to claim 1 of the present invention is a noble metal contact. A ribbon wire made of material and a leaf spring bent in an arc shape along the inner periphery of the housing case are welded at one end welded portion , and provided on the inner periphery of the housing case filled with a paste agent made of thixotropic material. relative to the gap, the second fulcrum portion in the vicinity of the welded portion is mounted to be floating, and the other end of the leaf spring, the first from the second fulcrum portion of the inner periphery of the housing case in the diametrical direction opposite the Rukoto is deformably fixed fulcrum, the ribbon line at the same time is contacted with a predetermined preload to the commutator, in which also configured to preload is applied to the second fulcrum portion.
[0008]
Further, in the brush for a small motor of the present invention, a gap provided in the inner periphery of the housing case filled with the paste agent made of the thixotropic material G, the welded portion 14 where the ribbon wire 11 and the leaf spring 12 are welded. On the other hand, it is mounted so as to be freely movable.
[0009]
In the brush for a small motor according to claim 2 of the present invention, the other end of the leaf spring 12 is bent outside the housing case 6 to form an external terminal 17.
[0010]
[Action]
In the brush for a small motor according to claim 1 of the present invention, the ribbon wire 11 made of a noble metal contact material and the leaf spring 12 bent in an arc shape in the outer peripheral direction are welded at the welded portion 14 at one end as described above. Since the housing case 6 is deformably mounted at the first fulcrum and the second fulcrum 15, when incorporated in the commutator 3, it is expanded at the second fulcrum 15 and the first fulcrum 16. Sufficient and stable spring pressure can be obtained.
[0011]
Also, in the brush for a small motor according to claim 1 of the present invention, the welded portion 14 where the ribbon wire 11 and the leaf spring 12 are welded is filled with a paste agent made of a thixotropic material G. Vibration can be absorbed and noise generation can be suppressed.
[0012]
Further, in the brush for a small motor according to claim 2 of the present invention, the other end of the leaf spring 12 is bent outside the housing case 6 to form the external terminal 17, so that the structure of the terminal can be simplified at low cost. Can be manufactured.
[0013]
[Example 1]
A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing the configuration of a small motor brush according to an embodiment of the present invention.
[0014]
As shown in FIG. 1, the brush for a small motor according to the first embodiment of the present invention is composed of a ribbon wire 11 made of a contact material such as a noble metal and a leaf spring 12, and the leaf spring 12 increases the length. Curved in an arc. When the ribbon wire 11 and the welded portion 14 of the leaf spring 12 are expanded by being assembled into the commutator 3, they contact at the second fulcrum 15.
[0015]
Also, the weld 14, by filling the grease-like thixotropic material G in the gap in the housing case 6, since the covered in contact with the pastes, can absorb vibration of the brush. Further, the leaf spring 12 is bent outward to form an external terminal 17.
[0016]
In the first embodiment of the present invention, the amount of deflection can be increased by a factor of two compared to the conventional U-curved ribbon line of FIG. Doubled. Further, the brush stagnation could be eliminated by providing the second fulcrum 15 and filling the thixotropic material G into 15 at the second fulcrum. Furthermore, the brush spring is divided into a contact material and a leaf spring, so that expensive noble metal contact materials can be reduced, which makes it possible to reduce costs.
[0017]
[Example 2]
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a cross-sectional view showing the structure of a brush for a small motor showing a second embodiment of the present invention.
[0018]
As shown in FIG. 2, the brush for a small motor according to the second embodiment of the present invention comprises a ribbon wire 21 made of a contact material such as a noble metal, a leaf spring 22 and a brush holder 23. As in Example 1, it is curved in an arc shape to increase the length. One end of the leaf spring 22 is welded to the ribbon wire 21, and the other end is welded and fixed to the brush holder 23. Similar to the first embodiment, the ribbon wire 21 and the welded portion 14 of the leaf spring 12 are in contact with each other at the second fulcrum 25 when the ribbon wire 21 and the welded portion 14 of the leaf spring 12 are spread by being assembled into the commutator 3.
[0019]
Further, since the welded portion 24 is covered with this paste agent by filling the gap provided in the housing case 6 with the grease-like thixotropic material G, the vibration of the brush can be absorbed.
[0020]
Also in the second embodiment of the present invention, the amount of deflection can be increased by a factor of about 2 compared to the conventional U-curved ribbon line of FIG. Doubled. In addition, the brush support can be eliminated by providing the second fulcrum 25 and filling the thixotropic material G into the 25 with the second fulcrum. Furthermore, the brush spring is divided into a contact material and a leaf spring, so that expensive noble metal contact materials can be reduced, which makes it possible to reduce costs.
[0021]
【The invention's effect】
As described above in detail, according to the present invention, the spring pressure of the brush can be sufficiently obtained even with a very small diameter, a stable spring pressure can be obtained, and a small amount of ribbon wire of expensive noble metal member is easy to be manufactured. A brush device with less noise can be provided.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a configuration of a brush for a small motor according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view showing the configuration of a small motor brush according to a second embodiment of the present invention.
FIG. 3 is a cross-sectional view showing a configuration of a conventional brush device.
FIG. 4 is a cross-sectional view showing a configuration of a conventional brush device for a small motor.
FIG. 5 is a cross-sectional view showing a configuration of a conventional cylindrical coreless vibration motor.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cylindrical coil 2 Coil support 3 Commutator 4 Rotating shaft 5 Field magnet 6 Housing case 7 Bearing 9 Brush
10 Weight
11, 21, 31, 41 Ribbon wire
12, 22 leaf spring
14, 24 Welded part
15, 25 2nd fulcrum
16, 26 First fulcrum
17 External terminal G Thixotropic material

Claims (2)

Ribbon wire made of noble metal contact material and leaf spring bent in an arc along the inner circumference of the housing case are welded at one end of the weld , and inside the housing case filled with paste agent made of thixotropic material against gap provided circumferentially, said second fulcrum portion in the weld vicinity is mounted so as to be floating, and the plate other end of the spring, the second from the fulcrum portion of the inner periphery of the housing case diametrically opposite the Rukoto is deformably fixed first fulcrum portion of the side, the ribbon wire is configured to simultaneously be in contact with a predetermined preload to the commutator, the preload to the second fulcrum portion is applied A brush for a small motor.   2. The brush for a small motor according to claim 1, wherein the other end of the leaf spring is bent outside the housing case to form an external terminal.

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