JP2001212511A - Vibration motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide s vibration motor, suited for the purpose of incorporating it in a portable wireless communications apparatus or a wrist watch, which can generate sufficiently effective vibration without the necessity to increase the outer diameter of a weight and consequently, increase the volume and the weight of the oscillating motor. SOLUTION: The vibration motor 4 is of such a structure that a bearing part 10 protrudes from the face of a motor housing 11 and the weight 3 has an almost half-moon shaped section i.e., a section having an eccentic center of gravity and further, an extension part 30 having the inner peripheral part avoiding the bearing part 10 is extended in the direction of the bearing part 10, at the rear part of the weight 3 the same half-moon outer shape as the weight 3. In addition, the motor 4 is characterized in that the overall length of the extension part 30 is sufficiently large as compared with the overall length of the weight 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibrating motor used for an incoming call function of a portable radio communication device such as a portable telephone and a time signal notifying section of a wristwatch.

[0002]

2. Description of the Related Art FIG.
This will be described with reference to FIG. A weight 103 is eccentrically fixed to the shaft 102 projecting from one end surface of the motor housing 111 by caulking. When the shaft 102 rotates, the shaft 102 rotates eccentrically, and the vibration motor 104 generates vibration.

[0003] Caulking is performed to fix the weight 103 and the shaft 102, and a caulking mark 109 is formed on the weight 102. Shaft 102 to maintain sufficient holding force by caulking
It is necessary to increase the joint between the weight and the weight 103. In the weight 103, a portion that does not contribute to the generation of vibration becomes large. For this reason, the eccentricity of the weight 103 is offset by this portion, and the eccentricity is not sufficiently large. Therefore, the vibration motor 104 could not generate sufficiently large vibration. If it is necessary to generate a large vibration, the outer diameter of the weight 103 needs to be increased.
4 Not only does the overall volume increase,
In order to be built into a portable radio communication device or a wristwatch, which has been increased in weight and has been increasingly required to be miniaturized in recent years, the volume and weight of the vibration motor become large and disadvantageous.

[0004]

It is not necessary to increase the outer diameter of the weight, so that a sufficiently large vibration can be generated without increasing the volume and weight. It is an object to provide a vibration motor suitable for the purpose of being incorporated in a wristwatch.

[0005]

An object of the present invention is to provide a motor housing, a shaft rotatably supported by a bearing portion of the motor housing, and a weight fixed to an end of the shaft in an eccentric state. In a vibration motor that directly connects a motor and the weight with the shaft and transmits motor rotation to the weight directly via the shaft, the bearing portion protrudes from a distal end surface of the motor housing, and the weight has a cross section. It has an eccentric shape that is approximately half-moon-shaped, and at the rear of the weight, an extended portion having the same semi-lunar outer shape as the weight and having an inner peripheral portion avoiding the bearing portion extends in the bearing portion direction. The vibration motor is characterized in that the total length of the extending portion is set to be sufficiently larger than the total length of the weight.

[0006] Since the entire length of the extending portion is set sufficiently large as compared with the entire length of the weight, a portion that does not contribute to the generation of vibration of the weight is reduced, and vibration can be generated efficiently.

Further, in the vibration motor, the weight and the shaft are fixed by welding.

[0008] By fixing the weight and the shaft by welding, compared to the fixing method by press fitting or caulking,
The joint between the shaft and the weight may be small,
Therefore, the weight only needs to have a size required for welding to the shaft. That is, the portion of the weight that does not contribute to the generation of vibration can be reduced, and the vibration can be emitted efficiently.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described with reference to FIGS. The present invention is not limited only to this embodiment.

FIG. 1 is an exploded perspective view of the vibration motor 4.
FIG. 2 is a partial cross-sectional perspective view of the vibration motor 4, and FIG. 3 is a perspective view of the vibration motor 4. A motor housing 11 having a cylindrical motor housing 11 has a motor housing 11
And a cylindrical bearing portion 10 having a diameter smaller than that of the base. The weight 3 is made of high specific heavy metal.

A bearing 6 is fixed to an upper portion of the bearing portion 10, and the shaft 2 is rotatably fixed. Shaft 2
Project from one end surface of the bearing 6. A mirror 5 is provided on one end surface of the bearing 3. The weight 3 is located above the mirror 5. The weight 3 has an eccentric shape with a substantially half-moon cross section, and an extended portion 30 having the same half-moon shape as the weight 3 and an inner periphery avoiding the bearing 10 is provided at the rear of the weight 3.
Is provided so as to extend in the bearing portion direction, and the entire length of the extension portion 30 is set sufficiently larger than the entire length of the weight 3.

The motor 1 has a terminal 7 for power supply. The portion of the shaft 2 protruding from the upper end surface of the weight 3 and the weight 3 are melted to form a nugget 9 so that the weight 3
And the shaft 2 are welded.

[0013]

According to the present invention, since the total length of the extending portion is set to be sufficiently larger than the total length of the weight, a portion that does not contribute to the vibration of the weight is reduced, and the vibration is efficiently performed. Can be generated.

Further, by fixing the weight and the shaft by welding, a joint portion between the shaft and the weight may be smaller than in a fixing method by press-fitting or caulking. What is necessary is just to have the size of the part required for welding. That is, the portion of the weight that does not contribute to the generation of vibration can be reduced, and the vibration can be emitted efficiently.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an embodiment according to the present invention.

FIG. 2 shows the same sectional view.

FIG. 3 shows the same perspective view.

FIG. 4 is an exploded perspective view of a vibration motor according to the related art of the present invention.

FIG. 5 shows the same sectional view. DESCRIPTION OF SYMBOLS 1 Motor 2 Shaft 3 Weight 4 Vibration motor 5 Lumirror 6 Bearing 7 Terminal 8 Through hole 9 Nugget 10 Bearing part 11 Motor housing 30 Extension part 101 Motor 102 Shaft 103 Weight 104 Vibration motor 105 Lumirror 106 Bearing 107 Terminal 108 Through hole 109 Caulking Mark 110 Bearing 111 Motor housing 130 Extension

Claims (2)

[Claims] 1. A motor housing, a shaft rotatably supported by a bearing portion of the motor housing, and a weight fixed to a tip of the shaft in an eccentric state, wherein the motor and the weight are connected to each other. In a vibration motor that is directly connected to a shaft and transmits motor rotation directly to the weight via the shaft, the bearing portion protrudes from a distal end surface of the motor housing, and the weight has an eccentric shape having a substantially half-moon cross section. Have
At the rear part of the weight, an extended portion having the same semicircular outer shape as the weight and having an inner peripheral portion avoiding the bearing portion is provided so as to extend in the bearing direction, and the total length of the extended portion is A vibration motor, wherein the vibration motor is set to be sufficiently larger than the total length of the weight. 2. The vibration motor according to claim 1, wherein said weight and said shaft are fixed by welding.