JP2001009372A - Cylindrical micro vibration motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the diameter of a cylindrical micro vibration motor small so as to be built in various kinds of apparatuses without making the thickness of a field magnet thin, by forming one end part of a motor housing to have a small diameter and integrally molding the housing parts of a bearing and of the field magnet to be projected outside. SOLUTION: In a cylindrical micro vibration motor 1, one end of a micro motor 2 is formed to have a small diameter by projecting one end of an opened cylindrical motor housing 3 to the outside, and a housing 5 of a bearing 4 and a housing 6 of a field magnet 9 are integrally molded. A cylindrical coreless armature is installed between the motor housing 3 and the field magnet 9, and is rotated integrally with a shaft 10 which penetrates the bearing 4 and a shaft insertion hole 7 of the field magnet 9. In addition, a brush holder 14 to form an end cap is mounted to the other end of the motor housing 3. Thereby, the diameter of the cylindrical micro vibration motor 1 is made small without making the thickness of the field magnet 9 thin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for producing a material having a diameter of 3 to
Regarding cylindrical vibration motors using ultra-fine cylindrical micro motors such as 4 mm, vibration generation of pagers (calling devices), mobile phones, toothbrushes, massagers, alarm clocks, watches, game controllers, resin molding machines, etc. Used for

[0002]

2. Description of the Related Art For example, as a prior art of the present invention, there is a cylindrical micro vibration motor invented by the present applicant and disclosed in Japanese Patent Application Laid-Open No. 11-69746.

[0003] The cylindrical micro vibration motor 101 will be described with reference to FIGS. In the cylindrical micro-vibration motor 101, portions common to the embodiment of the present invention are denoted by the same reference numerals as those of the embodiment of the present invention,
An explanation will be given of the embodiment of the present invention, and the explanation here will be omitted.

FIG. 7 shows a cylindrical micro vibration motor 101.
FIG. FIG. 8 is a sectional view taken along line BB in FIG.

In the cylindrical micro vibration motor 101, one end of a motor housing 103 of the cylindrical micro motor 102 is formed in a thin pipe shape having a small outer diameter, and a bearing house 45 for accommodating the bearing 4 is integrally formed and one end is provided outside. The bearing 4 is built in at one end of the bearing house 45.

A hollow stator yoke 8 having a projection 40 for regulating the axial movement of the bearing 4 between the motor housing 103 and the field magnet 9 and having a shaft insertion hole 7 extending in the axial direction. Have.

The projecting portion 40 of the stator yoke 8 is positioned between the other end surface of the bearing 4 and one end surface of a field magnet 9 fixed to the outer periphery of the stator yoke 8 so that the bearing 4 and the field magnet 9 Restricts axial movement.

[0008] The stator yoke 8 is a back yoke of the field magnet 9 for closing a magnetic circuit including the field magnet 9.

[0009]

When the diameter of the cylindrical micro-vibration motor having the above structure is further reduced, the thickness of the field magnet 9 or the thickness of the stator yoke 8 is reduced. There is a need.

However, if the thickness of the stator yoke 8 is too thin, the effect as the back yoke is lost, and the magnetic circuit may not be closed. Also,
As the field magnet 9 becomes thinner, the magnetic force becomes weaker,
For example, neodymium-iron-boron magnet (neodymi)
In the case of um-iron-boron magnet, when the thickness is smaller than about 0.7 mm, the magnetic force is sharply reduced.

As described above, when the diameter of the cylindrical micro vibration motor is reduced to, for example, 3 mm, there is a problem that the magnetic flux applied to the cylindrical coreless armature is reduced. When this magnetic flux is reduced, the output of the cylindrical micro motor is reduced, and the amount of vibration generated by the cylindrical micro vibration motor is also reduced. As a result, for example, when a mobile phone receives an incoming call, there is a problem that the user does not notice the call due to vibration

[0012]

Means for Solving the Problems In order to solve the above-mentioned problems, the invention according to claim 1 is characterized by comprising the following components or the following components.

One end of the motor housing 3 of the cylindrical micromotor is formed to have a small outer diameter, and a bearing housing for housing a bearing and a field magnet housing for housing a field magnet are formed integrally with the motor housing. One end is projected outside.

[0014] A bearing is provided at one end of the bearing housing portion.

[0015] A part of the field magnet is provided in the field magnet storage section.

The field magnet is hollow having a shaft insertion hole coaxial with the bearing and extending in the axial direction.

An eccentric weight for generating vibration is attached to a shaft that passes through the shaft insertion hole and protrudes from one end of the bearing.

At the other end of the motor housing,
A brush holder for holding a brush that forms a sliding contact with a commutator electrically connected to a cylindrical coreless armature that is housed in the motor housing and rotates integrally with the shaft is provided.

According to the first aspect of the present invention, the field magnet is directly housed in the field magnet housing so that the diameter of the cylindrical micro vibration motor can be reduced without reducing the thickness of the field magnet. can do. Although the stator yoke, which is the back yoke of the field magnet, is not used, even if the cylindrical micro vibration motor is provided with a thin stator yoke and the diameter is reduced, the stator yoke which is too thin is used as the back yoke. Does not work. Therefore, by eliminating the stator yoke while keeping the thickness of the field magnet as it is, the diameter of the cylindrical micro vibration motor can be reduced.

For this reason, the cylindrical micromotor does not become large in the axial direction, that is, the diameter can be reduced, so that it can be incorporated in various devices.

Further, when assembling the cylindrical micromotor, a stator yoke for holding the field magnet is not required, so that the number of parts to be assembled is reduced and the number of assembling steps can be reduced.

According to a second aspect of the present invention, in order to solve the above-mentioned problem, in the first aspect of the present invention, the brush holder is formed integrally with a bearing for supporting a shaft. .

According to the present invention, since the brush holder is formed integrally with the bearing, the number of parts to be assembled is reduced when assembling the cylindrical micromotor, and the number of assembling steps can be reduced.

[0024] Further, in order to solve the above-mentioned problem, the invention described in claim 3 provides the invention according to claim 1 or 2 in which
The inner diameter of the bearing housing portion and the inner diameter of the field magnet housing portion are substantially the same.

According to the present invention, the shape of the motor housing can be simplified, the motor housing with higher accuracy can be mass-produced, and the yield can be increased.

[0026]

FIG. 1 is a longitudinal sectional view of a cylindrical micro vibration motor 1 according to the present invention. FIG. 2 is a cross-sectional view taken along the line AA in FIG. FIG. 3 shows the brush holder 14.
FIG. FIG. 4 is an explanatory diagram when the brush holder 14 is viewed from the inner surface direction. FIG.
FIG. 3 is an explanatory diagram of a contact relationship between the brushes 16-1 and 16-2. FIG. 6 is an explanatory diagram of a contact state between the commutator 15 and the brush tip portions 16a and 16b. Hereinafter, a cylindrical micro vibration motor 1 will be described as an embodiment of the present invention with reference to FIGS.

Referring mainly to FIG. 1, a cylindrical micro-vibration motor 1 of the present invention has an outer diameter of 3 mm to 4 mm and a thickness of 0.2 mm made of a magnetic material having the other end of a cylindrical micro motor 2 opened. One end of the cylindrical motor housing 3 is formed to have a small outer diameter by protruding outwardly from the one end, and the bearing housing 5 and the field magnet housing 6 are integrally formed to form the bearing housing. The bearing 4 for rotatably supporting the shaft 10 is housed and arranged at one end in the portion 5. A hollow field magnet 9 is inserted from the direction of the other end of the motor housing 3, and the motor housing 3 and the field magnet 9 are fixed by bonding, fixing by bonding and press fitting, or fixing by welding.

The positions of the bearing 4 and the field magnet 9 with respect to the motor housing 3 are regulated using a separate jig when the cylindrical micromotor 2 is assembled.

The motor housing 3, the field magnet 9 and the bearing 4 are arranged concentrically. A cylindrical coreless armature is disposed in a gap between the motor housing 3 and the field magnet 9, and rotates integrally with a shaft 10 passing through the bearing 4 and the shaft insertion section 7 of the field magnet 9.

The main body of the cylindrical micro-vibration motor 1 is constructed by mounting a brush holder 14 constituting an end cap in which the other end of the motor housing 7 is formed of resin or the like.

The field magnet 9 is of a two-pole type having N and S poles in the circumferential direction. In order to generate a sufficiently large torque in the cylindrical micro vibration motor 1 having a small diameter. In addition, it is formed by using a magnet such as neodymium, boron, iron, or the like having a strong magnetic force.

A cylindrical coreless armature 18 constituting a rotating shaft is interposed in a radial gap between the motor housing 7 and the field magnet 9, and the shaft 10 provided on the coreless armature 18 has the bearing 4 and the bearing 10 at that position. The brush holder 14 is rotatably supported by a central through hole provided with the brush holder 14. Note that, in this embodiment, the cylindrical coreless armature 18 has a known turtle-shaped winding, and an adhesive tape (not shown) is wound around the center of the outer periphery. However, another winding method may be used.

The other end of the cylindrical coreless armature 18 is fixed to the outer periphery of the commutator hub 19 by using an adhesive or the like. The commutator hub 19 is formed of resin, and has a commutator 15 formed of a group of commutator pieces on the outer periphery of the other end.

At the commutator hub 19, the commutator pieces of the commutator 15 and the armature 18 are electrically connected. Commutator 15
, A brush 15 provided with a brush holder 14 is slidably contacted to perform commutator of the energized armature 18.

The center of the lower end of the vibration generating eccentric weight 11 is formed in a concave portion 13 serving as a concave portion, and the concave portion of the vibration generating eccentric weight 11 made of a high specific gravity metal such as an inverted L-shaped tungsten alloy is formed. An inverted L-shaped eccentric weight 11 for vibration generation is attached to the shaft 10 via a liner 21 between the eccentric weight 13 and one end of the motor housing 3. The bent part 12 is opposed to the outer peripheral part of the bearing housing part 5.

According to the extension bending deviation 12, the weight of the outer peripheral portion of the vibration generating eccentric weight 11 can be increased by that amount, so that a larger vibration can be generated without changing the length of the cylindrical micro vibration motor 1. Obtainable.

FIG. 2 is a sectional view taken along the line AA in FIG. The motor housing 3, the cylindrical coreless armature 18, and the field magnet 9 are arranged concentrically, and a shaft 10 extends through the center thereof. There is a gap between each. The motor housing 3 and the shaft 10 are made of a magnetic material. Therefore, since the motor housing 3 and the shaft 10 function as a yoke, the density of the magnetic flux flowing through the magnetic circuit of the cylindrical micromotor 2 is increased.

Next, the brush holder 14 and the commutator 15 will be described with reference to FIGS.

FIG. 4 is a view of the brush holder 14 as viewed from the inner surface in the axial direction, and FIG. 3 is a side longitudinal sectional view of the brush holder 14 for holding a pair of U-shaped brushes 16-1 and 16-2. Part 2
Brush holder 14 in which 2-1 and 22-2 are formed of resin
And the brush holding parts 22-1, 22-2.
The brushes 16-1 and 16-2 are held by the
At its tip is in sliding contact. [See FIGS. 5 and 6]

An insertion hole for passing the shaft 10 is formed in the center of the brush holder 14, and the shaft 10 is passed through the insertion hole.

As shown in FIG. 4, the lead wire 23- led to the outside at a position symmetrical with respect to 180 degrees is provided on the brush holder 14.
1. Through holes 25-1 and 25-2 are provided for passing the lead wires 23-1 and 23-2, and lead wires 24-1 and 24-2 of the lead wires 23-1 and 23-2 are provided.
Small diameter through-holes 26-1 and 26-2 for passing 4-2 are formed, and the conducting wires 24-1 and 24-2 are implanted.

One end of a pair of brush holders 22-1 and 22-2 projecting from the inner surface of the brush holder 14 is
Each of the brushes 16-1 and 16-2 is supported so as to slide on the commutator 15, and each of the brushes 16-1 and 16-2 has a good rectifying characteristic as shown in FIG. The brush tips 16-1 and 16-2 are axially 2
It is slid into contact with the commutator 15 by using one divided into stages.

The other end of each of the brushes 16-1 and 16-2 is provided with a two-piece piece 28-1, 2 integrally formed of the same conductive material.
8-2 is formed as an extension.
Conductor 2 passed through 4-2 slits 27-1 and 27-2
The coreless armature 18, the commutator 15, the brush 22-1, or 22-
2, and the conducting wire 24-1 or 24-2 is connected to the conducting wire.

After passing through the slits 27-1 and 27-2 of the forked pieces 28-1 and 28-2, the lead wires 25-1 and 25-2 are bifurcated from the conductive material by means such as soldering. 28-1 and 28-2.

[0045]

According to the first aspect of the present invention, the field magnet is directly housed in the field magnet housing so that the cylindrical micro vibration motor can be manufactured without reducing the thickness of the field magnet. The diameter can be reduced. Also,
Although the stator yoke, which is the back yoke of the field magnet, is not used, even if the cylindrical micro vibration motor is provided with a thin stator yoke and the diameter is reduced, the stator yoke that is too thin acts as a back yoke. Do not do. Therefore, by eliminating the stator yoke while keeping the thickness of the field magnet as it is, the diameter of the cylindrical micro vibration motor can be reduced.

For this reason, the cylindrical micromotor does not become large in the axial direction, that is, the diameter can be made small, so that it can be incorporated in various devices.

When a cylindrical micromotor is assembled, a stator yoke for holding a field magnet is not required, so that the number of parts to be assembled is reduced and the number of assembling steps can be reduced.

According to the second aspect of the present invention, since the brush holder is integrally formed with the bearing, the number of parts to be assembled when assembling the cylindrical micromotor is reduced, and the number of assembling steps can be reduced.

According to the third aspect of the invention, the shape of the motor housing can be simplified, the motor housing with higher accuracy can be mass-produced, and the yield can be increased.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a cylindrical micro vibration motor showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the same motor taken along line AA in FIG.

FIG. 3 is a vertical sectional view of a brush holder of the motor.

FIG. 4 is a drawing of a brush holder portion of the motor viewed from the inside.

FIG. 5 is a view showing a contact relationship between a brush and a commutator of the motor.

FIG. 6 is a view showing a contact relationship between a brush and a commutator of the motor.

FIG. 7 is an explanatory view of a conventional cylindrical micro vibration motor.

FIG. 8 is a cross-sectional view of the motor of the related art, taken along line BB.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylindrical micro vibration motor 2 Cylindrical micro motor 3 Motor housing 4 Bearing 5 Bearing storage part 6 Field magnet storage part 7 Shaft insertion hole 9 Field magnet 10 Shaft 11 Eccentric weight for vibration generation 14 Brush holder 15 Commutator 16 Brush 18 Cylindrical coreless armature 19 Commutator hub 22-1, 22-2 Brush holder 23-1, 23-2 Lead wire 24-1, 24-2 Conductive wire

Claims (3)

[Claims] 1. A cylindrical micro-vibration motor, comprising: One end of the motor housing 3 of the cylindrical micromotor 2 is formed to have a small outer diameter, and the bearing housing 5 for housing the bearing 4 and the field magnet housing 6 for housing the field magnet 9 are integrated with the motor housing 3. Forming and projecting outward at one end. The bearing 4 is provided at one end of the bearing housing 5. A part of the field magnet 9 is provided in the field magnet housing 6. The field magnet 9 is coaxial with the bearing 4 and has a hollow shape having a shaft insertion hole 7 extending in the axial direction. An eccentric weight for generating vibration is attached to a shaft that passes through the shaft insertion hole and protrudes from one end of the bearing. At the other end of the motor housing, there is provided a brush holder that holds a brush that forms a sliding contact with a commutator that is housed in the motor housing and that is electrically connected to a cylindrical coreless armature that rotates integrally with the shaft. That 2. The cylindrical micro vibration motor according to claim 1, wherein the brush holder is formed integrally with a bearing that supports a shaft. 3. The cylindrical micro-vibration motor according to claim 1, wherein the inner diameter of the bearing housing is substantially the same as the inner diameter of the field magnet housing.