JP2002045793A - Small-sized vibration motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized vibration motor constituted so that a rotary shaft is prevented from bending within an elastic deformation range without being plastically deformed, as if it ready to bend in any direction, to continue rotation. SOLUTION: In the small-sized vibration motor 1, a bearing part 9 is projected from the leading end surface of a motor housing 6 and a balance weight 3 has a mass eccentricity shape having an almost semicircular cross section and is equipped with a first balance weight extension part 12 extending in the direction of the bearing part 9 and a second balance weight extension part 18, and the first balance weight extension part 12 has a semicircular cross section and the inner peripheral part thereof has a shape avoiding the bearing part 9 while the second balance weight extention part 18 has a semicircular cross section and the inner peripheral part thereof has a shape avoiding the motor housing 6 and a part thereof has an annular part 5 covering the outer periphery of the motor housing 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small vibrating motor used for a notifying unit by vibrating a pager or a vibrator for radio calling.

[0002]

2. Description of the Related Art Japanese Unexamined Utility Model Publication No. 7-16573, filed on Aug. 11, 1993, is a prior art. According to this invention, a motor housing, a rotating shaft rotatably supported by a bearing portion of the motor housing, and a weight fixed to the tip of the rotating shaft in an eccentric state are included, and the motor and the weight are rotated. In a small vibration motor directly connected by a shaft and transmitting motor rotation directly to a weight via a rotating shaft, the bearing portion protrudes from a distal end surface of a motor housing, and the weight has an eccentric shape having a substantially half-moon cross section. At the rear of the weight, an extended portion having the same semicircular outer diameter as the weight and having an inner peripheral portion avoiding the bearing portion is provided so as to extend in the bearing direction, and is provided with the weight. The total length of the parts is set to be sufficiently large compared to their semi-lunar outer diameters, and the semi-lunar outer diameters of the weights and the extending parts are set to be substantially equal to the outer diameter of the cylindrical motor housing. And

[0003] In the above-mentioned invention, the extended portion of the weight comes into contact with the bearing portion, so that the rotating shaft is prevented from bending.
However, when the extended portion of the weight is bent in a direction not in contact with the bearing portion, there is a disadvantage that the bending of the rotating shaft cannot be prevented.

[0004]

Whatever direction the rotary shaft bends, the rotary shaft stops bending without plastic deformation and without elastic deformation, and can continue rotating. It is an object of the present invention to provide a motor.

[0005]

SUMMARY OF THE INVENTION In order to solve the problems of the present invention, an invention according to claim 1 includes a motor housing, a rotating shaft rotatably supported by a bearing of the motor housing, and a rotating shaft. A weight fixed in a state of eccentricity to the tip of the small vibration motor, which directly connects the small motor and the weight with the rotating shaft and directly transmits motor rotation to the weight via the rotating shaft. A bearing portion protrudes from a distal end surface of the motor housing, the weight has an eccentric shape with a substantially half-moon cross section, and a first weight extending portion and a second weight extending extending in the bearing direction. The first weight extension portion has a half-moon shape in cross section, an inner peripheral portion has a shape avoiding the bearing portion, and the second weight extension portion has a half-moon shape in cross section. The periphery has a shape avoiding the motor housing, and a part of the shape is And having an annular portion forming a circular ring covering the outer periphery of the housing.

According to the first aspect of the present invention, no matter in which direction the rotary shaft bends, the annular portion abuts on the motor housing, so that the rotary shaft is prevented from being bent to cause plastic deformation. be able to.

[0007] Further, the invention according to claim 2 is based on claim 1.
In the small vibration motor described in (1), a protrusion for restricting the movement of the weight in the axial direction is provided on the motor housing.

[0008] Further, the invention according to claim 3 is based on claim 2.
The small vibration motor according to any one of claims 1 to 3, wherein the projecting portions are arranged at three locations so as to have an equal interval in a circumferential direction of the motor housing.

According to the second or third aspect of the present invention, it is possible to prevent the weight from coming off the rotating shaft.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described with reference to FIGS. FIG. 1 shows a perspective view of a small vibration motor 1. FIG. 2 is an exploded perspective view of the small vibration motor 1. FIG. 3 is a sectional view of the weight 3 of the small vibration motor 1 and its periphery. FIG. 4 shows a sectional view of the motor housing 6.

The small vibration motor 1 includes a small cylindrical motor 2 and a weight 3. The weight 3 is made of a high specific heavy metal such as a tungsten alloy. The weight 3 has a half-moon shape in cross section. A rotating shaft through hole 10 is formed at the center of rotation of the weight 3, and the tip of the rotating shaft 4 is inserted and swaged.
It is fixed by bonding or welding. In the present embodiment, caulking by the dent 17 is employed. The tip of the rotating shaft 4 is inserted into the rotating shaft through hole 10 of the weight 3.

The first weight extension portion 12 of the weight 3 has a half-moon cross section, and the inner peripheral portion has a shape avoiding the bearing portion 9, and the second weight extension portion 18 has a half-moon cross section. The periphery has a shape avoiding the motor housing 6. The second weight circular portion 18 includes an annular portion 5 integrally formed so as to draw a circle when viewed from the axial direction. The outer diameters of the first weight extension portion 12 and the second weight extension portion 18 are the same. When the rotating shaft 4 is bent, the annular portion 5 of the weight 3 contacts the surface of the motor housing 6 before the rotating shaft 4 reaches plastic deformation, that is, in an elastically deformed state. Since the rotating shaft 4 is in a state of being elastically deformed, it can return to the original state again and can continue to rotate. Therefore, even if a strong external impact is applied, the small vibration motor 1 The vibration can be continuously generated while maintaining the function.

The small motor 2 will be described below. The small motor 2 includes a cylindrical motor housing 6 and a bearing 9 protruding from one end surface. A bearing 10 is fixed to the bearing 9. The bearing 10 is a sintered oil-impregnated bearing and rotatably supports the rotating shaft 4.

The motor housing 6 has a first protruding portion 7, a second protruding portion 8, and a third protruding portion 1 on a peripheral surface of a tip portion on the bearing portion 9 side.
9 are arranged so as to have an equal interval in the circumferential direction. A lumirror 11 is provided at the distal end of the bearing 9 to reduce friction on the sliding surface between the weight 3 and the bearing 10 or the bearing 9.

The distal end of the stator yoke 15 is press-fitted into the rear portion of the bearing 9 to fix the motor housing 6. In the stator 15, the magnet 14 is press-fitted into the stator yoke magnet press-fit portion 21. A coreless armature coil 13 is arranged in a gap between the motor housing 6 and the magnet 14, and the coreless armature coil 13 rotates integrally with the rotating shaft 4.

The fixing strength between the rotating shaft 4 and the weight 3 is loosened,
Even if the weight 3 tries to come off from the rotating shaft 4, the weight 3 is not removed from the first projection 7, the second projection 8, the third projection 19, and the weight 3.
The axial movement is restricted by the contact of the annular portion 5 formed integrally with the weight, so that the weight 3 cannot be removed from the small motor 2, and the weight 3 enters a certain machine, and It will not cause an accident.

[0017]

According to the first aspect of the present invention, no matter in which direction the rotary shaft bends, the annular portion comes into contact with the motor housing, so that the rotary shaft bends to plastic deformation. Can be prevented.

Further, the invention according to claim 3 is based on claim 2
The small vibration motor according to any one of claims 1 to 3, wherein the projecting portions are arranged at three locations so as to have an equal interval in a circumferential direction of the motor housing.

According to the second or third aspect of the present invention, it is possible to prevent the weight from coming off the rotating shaft.

[Brief description of the drawings]

FIG. 1 is a perspective view of a small vibration motor 1. FIG.

FIG. 2 is an exploded perspective view of the small vibration motor 1. FIG.

FIG. 3 is a sectional view of a weight 3 of the small vibration motor 1 and its periphery.

FIG. 4 shows a sectional view of the motor housing 6;

[Explanation of symbols]

 1, small vibration motor 2, small motor 3, weight 4, rotating shaft 5, annular portion 6, motor housing 7, first projecting portion 8, second projecting portion 9, bearing portion 10, bearing 11, lumirror 12, One weight extension part 13, coreless armature coil 14, magnet 15, stator yoke 16, through hole 17 for rotary shaft, dent 18, second weight extension part 19, stator yoke projection part 20, stator projection part 21, stator magnet press-fitting section

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference) 5D107 AA09 AA15 BB08 CC08 CC09 DD09 5H605 AA00 BB05 BB19 CC01 CC04 CC05 DD03 EB02 EB06 EB13 EB21 FF06 5H607 BB01 BB14 BB17 CC01 CC03 DD01 DD02 DD03 DD08 DD17 EJ07 GG01 GG01 GG01 GG02 5H623 AA00 BB04 BB07 GG11 HH06 HH10 JJ05 JJ06 LL04 LL09

Claims (3)

[Claims] 1. A small motor and said weight, comprising: a motor housing; a rotary shaft rotatably supported by a bearing portion of the motor housing; and a weight fixed to a tip of the rotary shaft in an eccentric state. In a small vibration motor that is directly connected to the rotating shaft and directly transmits motor rotation to the weight via the rotating shaft, the bearing portion protrudes from a distal end surface of the motor housing, and the weight has a substantially half-moon cross section. It has an eccentric shape, and comprises a first weight extending portion and a second weight extending portion extending in the bearing direction, the first weight extending portion has a half-moon shape in cross section, and an inner peripheral portion. Has a shape avoiding the bearing portion, the second weight extending portion has a semicircular cross section, an inner peripheral portion has a shape avoiding the motor housing, and a part thereof is an outer periphery of the motor housing. Characterized by having an annular portion that forms an annular shape that covers Type vibration motor. 2. The vibration motor according to claim 1, wherein a protrusion for regulating the movement of the weight in the axial direction is provided on the motor housing. 3. The small vibration motor according to claim 2, wherein the protrusions are arranged at three places so as to have a uniform interval in a circumferential direction of the motor housing. .