JP2571833Y2 - motor - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor used as a driving source for various electronic devices.

[0002]

2. Description of the Related Art For example, a structure shown in FIG. 7 is known as a motor with a brush applied to a VTR, a tape recorder and the like. Reference numeral 1 denotes a shaft which is rotatably supported by a pair of metallic bearings 2 and 3, and these bearings 2 and 3 are held by an insulating holder 4. The insulating holder 4 is made of a synthetic resin integrally formed with the yoke plate 5. Reference numeral 6 denotes a rotor unit including a core 8 and a coil 7 fixed to a shaft.

FIGS. 8 and 9 are a plan view and a sectional view, respectively, showing a bearing holder assembly 10 used in the motor shown in FIG. 7. In this bearing holder assembly 10, an insulating holder 4 is integrally formed with a yoke plate 5. It is constituted by. The motor uses such a bearing holder assembly 10 to form the insulating holder 4.
After a pair of bearings 2 and 3 are press-fitted and fixed in the through-hole 4 </ b> A in the inside, the shaft 1 is inserted into the bearings 2 and 3 to assemble. Next, a method of press-fitting and fixing the pair of bearings 2 and 3 will be described with reference to FIGS.

First, as shown in FIG. 10, tools for a guide bar 16, a die 17, and a punch 18 are prepared in advance, and a bearing holder assembly 10, and a pair of bearings 2, 3 are mounted on a bearing holder assembly 1.
The guide bar 16 is inserted in the order of the bearing 3, the bearing holder assembly 10, and the bearing 2 in a state where the guide bar 16 is arranged on the upper surface and the lower surface. Next, as shown in FIG. 11, the bearings 2 and 3 are pressed into the through holes 4A in the insulating holder 4 almost simultaneously by lowering the punch 18 and pressing the bearings 2. Subsequently, as shown in FIG. 12, by pulling the guide bar 16 downward and returning the punch 18 upward, the bearing assembly 14 in which the pair of bearings 2 and 3 are press-fitted and fixed to the bearing holder assembly 10 is obtained. .

Since the outer diameters of the bearings 2 and 3 and the inner diameter of the insulating holder 4 are press-fitted and fixed, they are tightly fitted. The outer diameter of the guide bar 16 is set slightly smaller than the inner diameter of each of the bearings 2 and 3.

According to such a press-fitting and fixing method, the pair of bearings 2 and 3 can be press-fitted into the through hole 4A in the insulating holder 4 almost at the same time using one guide bar 16, so that it is simple and inexpensive in a short time. Advantages can be obtained, such as being able to assemble using a simple assembling apparatus, and having extremely good coaxiality accuracy of the inner diameters of the pair of bearings 2 and 3.

[0007]

The conventional motor has the advantage that it can be assembled by a simple method, but has the following problems. (1) When a metal sintered body or a resin material is used for the bearings 2 and 3, if the press-fitting allowance between each of the bearings 2 and 3 and the insulating holder 4 is large, the inner diameter of each of the bearings 2 and 3 is slightly Since the contraction occurs, the bearings 2 and 3 are in a state where the guide bar 16 is tightened. Therefore, when the guide bar 16 is pulled out, the fixing position of the upper bearing 2 is particularly shifted as shown in FIG. As a result, not only the appearance of the motor becomes poor, but also noise during rotation increases and the life is shortened.

(2) Guide bar 1 for inner diameter of bearing 2
Since the clearance of the outer diameter of the bearing 6 is very small, the bearing 2 is positioned with respect to the motor mounting surface 5A in FIG.
Inner surface 2A is inclined. For this reason, the perpendicularity of the shaft 1 to the motor mounting surface 5A is deteriorated. Alternatively, even if the motor has a good degree of verticality, the synthetic resin forming the insulating holder 4 causes a creep phenomenon due to the side pressure applied to the shaft 1 during rotation and environmental conditions. As a result, the surface 2A is inclined and the verticality is deteriorated.

(3) Since the shaft 1 and the yoke plate 5 are electrically connected via the insulating holder 4, for example, when a pulley is attached to the shaft 1 and a rubber belt or the like is attached thereto, the rubber belt is rotated during rotation. The static electricity generated by the friction is charged on the pulley. For this reason, noise is generated by the charged static electricity. Alternatively, electromagnetic wave noise generated inside the motor is scattered outside the motor using the shaft 1 as an antenna.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has been made in consideration of the problems described above, and is intended to prevent a displacement of a fixed position of a bearing, improve the verticality of a shaft, and prevent the influence of noise. The purpose is to provide.

[0011]

In order to achieve the above object, the present invention provides a motor in which a metal bearing for rotatably supporting a shaft is held by an insulating holder, and a rotor portion is fixed to the shaft. , Wherein a yoke plate is projected from an inner peripheral surface of the insulating holder and is brought into contact with a bottom surface of the metallic bearing.

[0012]

Since the yoke plate protruding from the inner peripheral surface of the insulating holder is in contact with the bottom surface of the bearing, the fixed position of the bearing does not deviate. Further, since the yoke plate is in contact with the bottom surface of the bearing, the inclination of the inner peripheral surface of the bearing with respect to the motor mounting surface can be improved, so that the verticality of the shaft can be improved. Further, since the bearing and the yoke plate are electrically connected to each other, even if static electricity is generated, they are grounded without being charged, so that the influence of noise can be prevented.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of the motor of the present invention.
Is a shaft, 2 and 3 are a pair of metallic bearings, 4 is an insulating holder, 5 is a yoke plate, and 6 is a rotor portion including a coil 7 and a core 8. The above is the same as the conventional example of FIG.

Here, the yoke plate 5 has a planar structure and a sectional structure as shown in FIGS. That is,
FIGS. 2 and 3 show the structure of the yoke plate 5 before assembling. The center portion of the circular shape is concave, and a through hole 5B is formed here. Further, around the through hole 5B, a plurality of guide holes 5C for forming the insulating holder 4 by flowing a plurality of, for example, three synthetic resins are formed. 4 and 5 show a plan view and a sectional view after the insulating holder 4 is formed.

Here, assuming that the diameter of the shaft 1 in the insulating holder 4 is D1, and the outer diameters of the bearings 2 and 3 are D2,
The diameter D of the through hole 5B is usually set so as to satisfy the relationship of D2>D> D1. However, when radial ball bearings are used as the bearings 2 and 3, when the diameter of the inner ring of the radial ball bearing is D3, the diameter D of the through hole 5B has a relationship of D> D3. The insulating holder 4 is formed integrally with the yoke plate 5 by allowing the synthetic resin to flow into the yoke plate 5 from the guide hole 5C as shown in FIGS. Thereby, the yoke plate 5
Has a structure protruding from the inner peripheral surface of the through hole 4A of the insulating holder 4. 5D indicates an end surface of the protruding portion of the yoke plate 5, and serves as a fixing surface when the bearing 2 is press-fitted in a later step.

Next, by applying the method as shown in FIGS. 10 to 12 to the bearing holder assembly 10 thus configured, the through hole 4 in the insulating holder 4 is formed.
A, a pair of bearings 2 and 3 are press-fitted and fixed to form a bearing assembly 14 as shown in FIG. As is clear from FIG.
The bearing 2 is fixed by contacting the bottom surface 2B with the end surface 5D of the yoke plate 5. That is, the yoke plate 5
End surface 5D serves as a stopper for the bearing 2.

According to the motor of this embodiment, the following effects can be obtained. (1) When a metal sintered body or a resin material is used for the bearings 2 and 3, even if each of the bearings 2 and 3 tightens the guide bar 16, the end surface 5 </ b> D of the yoke plate 5 functions as a stopper. Therefore, it is possible to prevent the fixed position of the bearing 2 from being shifted as shown in FIG. As a result, the appearance defect of the motor is eliminated, and not only noise during rotation is suppressed but also the life is prolonged.

[0018] (2) bearing 2 that is fixed to those <br/> against the end face 5D of the yoke plate 5. Here, the parallelism between the motor mounting surface 5A and the end surface 5D of the yoke plate 5 can be relatively easily processed with high precision by press working. Further, the inner peripheral surface 2A and the bottom surface 2B of the bearing 2 can be machined with very high precision. Therefore, the inner peripheral surface 2A of the bearing 2 can be fixed to the motor mounting surface 5A without tilting,
In addition, since the creep phenomenon of the synthetic resin due to the side pressure on the shaft 1 during rotation, environmental conditions, and the like can be suppressed, the verticality of the shaft 1 can be improved.

(3) Since the shaft 1 and the yoke plate 5 are electrically connected via the bearing 2, the yoke plate 5 is grounded to the chassis so that static electricity is generated due to friction of the rubber belt during rotation. This static electricity is removed by a route from the shaft 1, the bearing 2, the yoke plate 5, and the chassis. For this reason, noise does not occur because static electricity is not charged. In addition, since the electromagnetic wave noise generated inside the motor is also removed by the same route, it is not scattered outside the motor.

In the embodiment, three recesses are formed in the yoke plate 5.
Although an example in which five guide holes 5C are formed is shown, any number of guide holes 5C can be selected as long as the number is one or more. Alternatively, a cutout may be provided in the through hole 5B. Although the bearing 2 is shown as being in contact with the end face 5D of the yoke plate 5, a similar structure can be applied to the other bearings 3. Further, the present invention is not limited to a motor with a brush, and the same effect can be obtained when applied to a brushless motor, a coreless motor, or the like.

[0021]

As described above, according to the present invention, the yoke plate is made to protrude from the inner peripheral surface of the insulating holder, and a metal bearing is brought into contact with the yoke plate to ground the yoke plate. Therefore, displacement of the fixed position of the bearing can be prevented, the verticality of the shaft can be improved, and the influence of noise can be prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a motor according to the present invention.

FIG. 2 is a plan view showing a yoke plate used in the embodiment.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a plan view showing a bearing holder assembly used in this embodiment.

FIG. 5 is a sectional view taken along line AA of FIG. 4;

FIG. 6 is a cross-sectional view showing a structure in which a bearing is press-fitted and fixed to a bearing holder assembly in the present embodiment.

FIG. 7 is a sectional view showing a conventional motor.

FIG. 8 is a plan view showing a bearing holder assembly used in a conventional example.

FIG. 9 is a sectional view taken along line AA of FIG. 8;

FIG. 10 is a sectional view showing a method of press-fitting and fixing a bearing to a bearing holder assembly in a conventional example.

FIG. 11 is a cross-sectional view showing another method for press-fitting and fixing a bearing to a conventional bearing holder assembly.

FIG. 12 is a cross-sectional view showing another method for press-fitting and fixing a bearing to a conventional bearing holder assembly.

FIG. 13 is a cross-sectional view for explaining a conventional defect.

[Explanation of symbols]

 Reference Signs List 1 shaft 2, 3 bearing 4 insulating holder 4A through hole 5 yoke 5A motor mounting surface 5B through hole 5C guide hole 5D end face 10 bearing holder assembly 14 bearing assembly 16 guide bar 17 die 18 punch

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-58-19140 (JP, A) JP-A-63-226443 (JP, A) JP-A-63-181635 (JP, A) JP-A-54 9701 (JP, A) Fully open Showa 60-151258 (JP, U) Fully open Showa 52-107312 (JP, U) Fully open flat 4-28754 (JP, U) Fully open flat 4-2952 (JP, U)

Claims (1)

(57) [Scope of request for utility model registration] 1. A motor in which a metallic bearing for rotatably supporting a shaft is held by an insulating holder and a rotor portion is fixed to the shaft, a yoke plate protrudes from an inner peripheral surface of the insulating holder. A motor that is brought into contact with the bottom surface of the metallic bearing.