JP2872623B2 - Vibration motor without output shaft - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration motor having no output shaft which is suitable as a silent information source of a small pager or a vibration source of a massager.

[0002]

2. Description of the Related Art Conventionally, a vibration motor having no output shaft, particularly a flat coreless motor, is disclosed in
Japanese Patent Application Laid-Open No. 63-111868. As shown in FIG.
An eccentric rotor R is disposed in a housing H composed of a rotor holder 3 and a bracket 29.
The structure is such that the case 28 and the bracket 29 are rotatably supported by oil-impregnated bearings 32 and 33 respectively disposed on the case 28 and the bracket 29 via the shaft 31. Since the eccentric rotor R is fixed to the shaft 31, the housing H
The position is determined by the shaft 31 which is flush with the shaft.

[0003]

However, in the case of the twin bearing type as described above, the coaxiality of the upper and lower bearings becomes important. In the case of a coin-type flat motor having a thickness of about 3 mm, a case,
10μ coaxiality between the fitting part of the bracket and each bearing
The precision of each component is required, for example, it is necessary to keep the accuracy below m. Such a problem could be solved by using a so-called cantilever type bearing in which only one of the bearings was used. However, if the fitting portion of the bearing is lengthened, the fitting margin of the rotor holder fitted to the shaft is shortened, and this also poses a practical problem. And in the above configuration, the housing is
It is difficult to insulate the case and bracket
Battery-type vibration using the case and bracket as power supply electrodes
It is difficult to configure the motor.

Further, as a vibration motor of a fixed shaft type in which the shaft does not protrude outside the housing, there is one as disclosed in FIG. 1 of Japanese Patent Publication No. 59-14966. However, such a configuration is difficult to assemble because both ends of the shaft are fixed to the bracket as can be determined from the drawings. That is, in order to attach the rotor 12 to the bearings 5 and 6 fitted to the brackets 2 and 3 via the shaft support brackets 10 and 11, the stator 7 is in the way and cannot be normally assembled.

The bearings 5 and 6 are not attached to the shaft 4 but are unavoidably arranged on the brackets 2 and 3 for drawing out the lead wire 9, so that the outer diameter must be large. Since the sliding loss of the shaft support brackets 10 and 11 cannot be made as small as that of the shaft, it is very large and is not practical.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a vibration motor having no output shaft which utilizes the vibration of the motor itself to overcome the above-mentioned problems without having to rotate a shaft. It was created with a focus on what should be done, without compromising the accuracy of each part more than necessary, easy to assemble, and therefore cost-effective,
Another object of the present invention is to provide a vibration motor having no output shaft and excellent in handleability .

[0007]

According to the present invention, an eccentric rotor comprising a plurality of armature coils is disposed in a housing comprising a case and a bracket, a commutator is disposed on the rotor, and a brush is mounted on the commutator. In a vibration motor without an output shaft, which is slidably contacted so that a shaft supporting the rotor does not protrude outward from the housing, only one end of the shaft is fixedly supported on a part of the housing, and the other end of the shaft is And a rotor in which a commutator and a bearing are integrated is incorporated, and the other end of the shaft is covered with the housing and is insulated from the housing.

[0008]

As described above, only one end of the shaft is fixedly supported on a part of the housing, and a rotor having a commutator and a bearing integrated therefrom is incorporated from the other end of the shaft. The other end of the shaft is connected to the housing by the housing. Because it is configured so that it is covered and the other end is insulated from the housing, the problem of coaxiality of the upper and lower bearings is eliminated, the rotating part is not exposed to the outside, and as a vibration motor that is extremely easy to handle. It is easy to configure.

[0009]

First Embodiment A first embodiment of the present invention is applied to a lithium battery type flat coreless vibration motor as shown in FIG. 1, and is provided at a central portion of a case 1 constituting a part of a housing. One end of a stainless steel shaft 2 is press-fitted via a shaft holder 1a, and the other end is a bracket 9
And the shaft 2 is almost within the thickness from the open end .
In addition, a bearing 3 made of resin or sintered metal impregnated with oil and a rotor 5 eccentric via a rotor holder 4 are mounted. The eccentric rotor 5 has two armature coils 6.6 formed by winding a rectangular copper wire at a pitch of about 120 ° as shown in FIG. At the same time, they are integrally fixed to the flat plate commutator 8 by soldering.

On the other hand, a bracket 9 which is a part of the housing
Is formed by outsert molding of insulating means 10 such as polyethylene terephthalate resin on the outer periphery, and a magnet 11 made of neodymium facing the rotor 5 through a gap is placed. ,
13 is brought into sliding contact with the flat plate commutator 8. Therefore, the rotor 5 is urged toward the case 1 and is held down by the thrust washer S1.

In this embodiment, in order to use the case 1 and the bracket 9 as power supply electrodes, one of the brushes 12 is used.
Together are soldered directly to the bracket 9, the other brush 13, passes under the magnet 11 through the flexible plate 14, which is connected to the inside of the casing 1, the shaft
By providing a gap between the other end of 2 and the bracket 9,
The other end of the shaft 2 is insulated from the bracket 9
You . The rotor holder 4 is not particularly required, and may be directly integrated with resin as in Japanese Utility Model Application No. 63-111868, or the bearing 3 may be integrated directly with the flat plate commutator 8. Further, in addition to the shaft holder 1a, for example, a case in which the center of the case 1 is burred may be used.

Next, the principle of rotation of the motor will be described with reference to FIG. 3. The magnet 11 is equally polarized N and S alternately at 90 ° open angle. The winding end of 6.6 is connected to each segment 8a, 8c of the commutator 8, the end of winding is connected to the same segment 8b, and the 180 ° opposing segments are short-circuited by the conductors 15a, 15b and 15c. Have been.

When positive and negative voltages are applied to the case and the bracket by a power source such as a battery, a current flows through the armature coil 6.6 in the direction of arrow A at the position of "0 °", and the rotor 5 Arrow B according to Fleming's left hand rule
A torque is generated in the direction of and the motor rotates. Hereinafter, the same applies to the position of “60 °”, and since there is no counter-torque that hinders rotation at other positions, the rotation is continued cyclically as long as power is supplied.
Since this rotor has a center of gravity at a position shifted in the radial direction from the center, a large centrifugal force is generated during rotation, and the rotor functions as a vibration motor.

Although the above embodiment has been described as including two armature coils, it has three armature coils as disclosed in Japanese Utility Model Application No. 63-111868 previously filed by the present applicant. Of course, it may be something.

[0015]

Second Embodiment FIG. 4 shows a cross section of a main part of a second embodiment applied to a cylindrical vibration motor having no output shaft. That is, reference numeral 16 denotes a metal dry battery type cylindrical case, the surface of which is plated with a metal having good electrical conductivity, and a bracket which also serves as an insulator made of a thick double-sided printed wiring board is provided at an opening edge portion of the case 16. 17 are fitted. Note that this bracket may be a molded product made of polyethylene terephthalate resin instead of a printed wiring board.

A recess 16 is formed at the center of the ceiling of the case 16.
a, and the shaft 18 is press-fitted. The shaft 18 includes oil-impregnated bearings 19 and 20, and at least a part of one of the three poles is omitted.
Is mounted rotatably.

A cylindrical commutator C is attached to the rotor 23, and a pair of brushes 24 and 25 are slid on the sliding surface of the commutator C.
There are seven plants. One brush 24 is a bracket 17
The other brush 25 is implanted on the other electrode pattern 17c disposed on the outer surface through a through hole 17b insulated from the electrode pattern 17a.

If the bracket is made of a resin molded product instead of a printed wiring board, a brass plate may be outsert molded instead of the pattern. In the figure, reference numeral 26 denotes a cylindrical field magnet disposed on the rotor 23 with a gap therebetween, the magnetic center of which is shifted upward with respect to the center of the rotor 23, whereby the rotor 23 is constantly biased upward. Is to be kept. Reference numeral 27 denotes two or three polyester washers which act as sliders under the urging force of the rotor 23. Therefore, since the rotor 23 is always urged in the direction of the slider 27, there is no possibility that the rotor 23 will slip downward and the position of the rotor 23 is stabilized.

With such a configuration, one of the brushes 24 can be used as the electrode pattern 1 when the bracket is assembled to the case 16.
Since it is electrically connected to the case by 7a, a vibration motor of a dry cell type can be obtained as a whole. Here, the other end of the shaft 18 or the opposite bracket
If the surface, etc. is made of insulating material,
There is no problem even if it makes contact. Also in such an embodiment, since the rotor is at the position where the center of gravity moves in the radial direction, a large centrifugal force is generated during rotation, and the rotor functions as a vibration motor. In each of the above embodiments, the battery type in which the lead wire and the terminal are eliminated and the case and the bracket are used as electrodes has been described. In the flat type, one end of the shaft may be fixed to the bracket side instead of the case.

[0020]

As described above, according to the present invention, only one end of the shaft is fixedly supported on a part of the housing, and the other end of the shaft incorporates a rotor having a commutator and a bearing integrated therein. Since the end is covered with the housing and the other end is insulated from the housing, the rotating part is not exposed to the outside, so that it is easy to construct a vibration motor having extremely excellent handleability.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a first embodiment of the present invention.

FIG. 2 is a plan view of the eccentric rotor according to the embodiment.

FIG. 3 is an operation development diagram in the embodiment.

FIG. 4 is a sectional view of a main part of a second embodiment of the present invention.

FIG. 5 is a sectional view of a main part of a conventional vibration motor without an output shaft.

[Explanation of symbols]

 1, 16 ‥‥ case 2 ‥‥ shaft 5, 23 ‥‥ eccentric rotor 9, 17 ‥‥ bracket 10 ‥‥ insulation means

Claims (1)

(57) [Claims] An eccentric rotor comprising a plurality of armature coils is disposed in a housing comprising a case and a bracket, a commutator is disposed on the rotor, and a brush is slidably contacted with the commutator to support the rotor. In a vibration motor without an output shaft, a shaft to be fixed does not protrude outward from the housing, only one end of the shaft is fixedly supported on a part of the housing, and a commutator and a bearing are integrated from the other end of the shaft. A vibrating motor without an output shaft, wherein the rotor is incorporated, the other end of the shaft is covered with the housing, and the housing is insulated from the housing.