JPH0556597A - Structure for fixing bearing of motor - Google Patents

Abstract

PURPOSE:To reduce the cost of manufacture by machining a bearing housing easily and highly accurately only by press work. CONSTITUTION:Periphery receiving parts 32 for positioning the periphery of a bearing 15 and end-face receiving parts 33 for positioning an end face of the bearing 15 are formed independently and alternately in a circumferential direction on a bearing housing 11 integrally formed in the center part of a motor case 10 or an end plate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing fixing structure integrally formed with a motor case or an end plate.

[0002]

2. Description of the Related Art In a small motor such as a stepping motor, a bearing structure for rotatably supporting a motor shaft is provided in a motor case and / or an end plate.
A structure is used in which a bearing housing for positioning and fixing a ball bearing or the like is integrally formed. 5 and 6 are partial vertical cross-sectional views illustrating a conventional bearing structure of this type. In the bearing structure of FIG. 5, only the outer peripheral surface of the ball bearing 53 is press-fitted and fixed by the bearing housing 52 formed integrally with the motor case 51, and the axial direction of the ball bearing 53 is fixed by a press-fitting jig (not shown) or the like. A structure is adopted in which the position is set and the outer peripheral surface is fixed to the inner peripheral surface of the bearing housing 52 by press fitting or adhesion. In the bearing structure of FIG. 6, the bearing housing 54 is formed by deep drawing in the center of the motor case 51, and the outer peripheral surface of the ball bearing 53 is press-fitted or adhered to the inner peripheral surface of the bearing housing 54, and By adopting a structure in which the end surface of the bearing 53 (the outer end surface in the illustrated example) is brought into contact with the end surface of the bearing housing 54, both the outer peripheral surface and the end surface of the bearing 53 are pressed and positioned and fixed.

[0003]

However, the above-mentioned conventional bearing fixing structure has the following problems at the time of assembling the motor and manufacturing the parts. That is, FIG.
In the above structure, it is necessary to use a press-fitting jig or the like to position the bearing 53 in the axial direction, and in order to fix the inner peripheral surface of the bearing 53, a press-fitting method with a large tightening margin or a fixing method using an adhesive is adopted. Therefore, there is a problem that the number of assembling steps is increased and the yield is not good. On the other hand, in the structure of FIG. 6, it is difficult to obtain the machining accuracy such as the roundness and the concentricity of the bearing housing 54 only by deep drawing, and therefore it is necessary to separately perform the machining, which increases the man-hours. There is a problem that the cost will increase.

The present invention has been made in view of the above technical problems, and an object of the present invention is that it does not require a jig for positioning a bearing, has no drawing step, and is easy to perform only by press working. (EN) It is possible to provide a motor bearing fixing structure that can be processed with high accuracy, can secure sufficient processing accuracy, and can be manufactured at low cost.

[0005]

According to the motor bearing fixing structure of the present invention, the outer peripheral receiving portion for positioning the outer periphery of the bearing and the end surface of the bearing are positioned in the bearing housing portion integrally formed with the motor case or the end plate. The above object is achieved by forming the end face receiving portions that are formed independently of each other. Further, according to another aspect of the present invention, in addition to the above-described configuration, the outer peripheral receiving portion and the end surface receiving portion are formed by press working, or a ball bearing is used as the bearing, thereby more efficiently It achieves the purpose.

[0006]

1 is a vertical sectional view illustrating the structure of a motor having a bearing fixing structure according to the present invention. In FIG. 1, a drum-shaped motor case 1 with one end open
A bearing housing 11 is formed in the central portion of 0, and a mounting plate 12 is fixed to the open end surface of the motor case 10 by fixing means such as caulking 13.
Another bearing housing 14 is formed at the center of the motor shaft. The mounting plate 12 also serves as an end plate that seals the open end surface of the motor case 10. Bearings (ball bearings in the illustrated example) 15 and 16 are positioned and fixed in the bearing housings 11 and 14 by press-fitting, bonding, or the like.
A motor shaft 17 is pivotally supported by 5 and 16.

A rotor 18 is press-fitted and fixed at a position of the motor shaft 17 in the motor case 10. The rotor 18 is magnetized to the N and S poles at a predetermined pitch in the circumferential direction on the outer peripheral portion of the rotor 18. A magnet 19 is formed. Inside the motor formed by the motor case 10 and the mounting plate 12, two stator units 5 facing the rotor magnet 19 with a gap are provided.
0 and 60 are arranged side by side in the axial direction. Each of the stator units 50 and 60 has a structure in which the exciting coils 20 and 21 are housed between the inner and outer yokes having pole teeth, and constitutes the exciting phase of the motor. It has two excitation phases.

In the illustrated example, the first phase outer yoke 22 is formed integrally with the motor case 10 by cutting and raising a part of the end surface of the motor case 10, and the first phase inner yoke 23 and The second-phase inner yoke 24 is joined back to back, and the second-phase outer yoke 25 is integrally formed with the mounting plate 12 by cutting and raising a part of the mounting plate 12. The first-phase outer yoke 22 and the second-phase outer yoke 25 may be made of independent separate members and fixed to the motor case 10 and the mounting plate 12 by welding or the like. .. Thus, the first exciting coil 20 wound around the bobbin 26 is provided inside the first inner and outer yokes 22 and 23.
By installing the first phase stator unit 5
0, and by mounting the second exciting coil 21 wound around the bobbin 27 inside the second inner and outer yokes 24, 25, the second-phase stator unit 60
Is configured.

Each of the yokes 22, 23, 24, 25 is provided with a plurality of pole teeth formed at a predetermined pitch in the circumferential direction so as to face the rotor magnet 19 with a predetermined gap. The bobbins 26, 2
7 is made of, for example, an insulating material such as plastic, and portions 26A and 27A thereof are exposed from the side surface notch 31 of the motor case 10. The exposed portions are connected to the exciting coils 20 and 21, respectively. Motor terminals 28, 29
(4 or 6 in total) are fixed so as to project to the outside. A rotational force extracting means 30 such as a pulley is fixed to the output side projection of the motor shaft 17.

Each of the motor terminals 28 and 29 projecting to the substantially same side in the circumferential direction of the motor case 10 is formed of a conductive rod-shaped or plate-shaped metal having a predetermined rigidity. Therefore, at the tip of each motor terminal 28, 29,
The circuit board 35 is fixed by soldering or the like. The circuit board 35 is for connecting the motor terminals 28 and 29 to an external control circuit, and a circuit pattern connected to the motor terminals 28 and 29 is formed on the circuit board 35. In the illustrated example, the circuit board 35
Is arranged on the side surface of the motor, that is, on the outside of the peripheral surface of the motor case 10.

FIG. 2 is a front view of the motor case 10 in FIG. 1 as seen from the inside of the motor, and FIG. 3 is a line 3-- in FIG.
3 is a vertical cross-sectional view of the motor case 10 taken along line 3 in FIG.
FIG. 4 is a partial vertical cross-sectional view showing a state where a ball bearing is fixed to a bearing housing. 1 to 4, a bearing housing 11 is integrally formed at the center of a motor case 10. The bearing housing 11 has an outer periphery of a bearing (ball bearing in the illustrated example) 15 (outer periphery of an outer race). ), And an end surface receiving portion 33 for positioning and fixing the end surface (the outer end surface of the outer race in the illustrated example) of the bearing 15 are individually formed. ing. The outer peripheral receiving portion 32 and the end surface receiving portion 33 are formed by sheet metal pressing, and in the illustrated example,
It is formed in four places alternately on the circumference. The ball bearing 15 regulates the concentricity by press-fitting with the outer peripheral receiving portion 32, and the end face receiving portion 33.
It is positioned and fixed to the motor case 10 by restricting the axial position by abutting with.

In FIG. 1, the end plate (mounting plate) 1
A bearing housing 14 is integrally formed at the center of 2, and this bearing housing 14 also has substantially the same structure as the bearing housing 11. That is, the bearing housing 14 includes an outer peripheral receiving portion 37 for positioning and fixing the outer periphery (outer periphery of the outer race) of the bearing (ball bearing in the illustrated example) 16 and the bearing 1.
6 end face (in the illustrated example, the outer end face of the outer race)
The end face receiving portions 38 for positioning and fixing are formed individually. These outer peripheral receiving portions 3
7 and the end surface receiving portion 38 are formed by sheet metal pressing, and are formed, for example, at four locations alternately on the circumference. Therefore, the ball bearing 16 is also attached to the end plate (mounting plate) 12 in a state where the concentricity is regulated by the press-fitting engagement with the outer peripheral receiving portion 37 and the axial position is regulated by the contact with the end face receiving portion 38. Positioning is fixed. Since the end plate 12 is also positioned and fixed to the motor case 10, the ball bearing 16 is also positioned and fixed to the motor case 10.

According to the embodiment described above, the bearing housings 11 and 14 integrally formed in the central portions of the motor case 10 and the end plate 12 are the ball bearings 15,
Outer circumference receiving portions 32, 37 for positioning the outer circumference of 16
Since it has a structure in which the end faces 33 and 38 for positioning the end faces of the ball bearings 15 and 16 are alternately and independently formed in the circumferential direction, the outer periphery receiving part and the end face receiving part are simultaneously raised by press working. It is possible to process with high accuracy, and it is possible to easily increase the positioning accuracy of the bearing without the need for machining or the like. Further, since the jig for positioning the bearing, which is required in the conventional example of FIG. 5, can be omitted, it is possible to manufacture at low cost. Further, since the drawing process is not included in the housing processing as in the conventional example of FIG. 6, the processing accuracy can be easily increased, and the finishing processing (machining) can be omitted.

In the above embodiment, the ball bearings 15 and 16 are used. However, the present invention is also applicable to the case where a roller or needle bearing or a bush type plain bearing is used. It can be applied and the same effect can be obtained.

[0015]

As is clear from the above description, according to the bearing fixing structure for a motor of the present invention, the outer peripheral support for positioning the outer periphery of the bearing in the bearing housing portion integrally formed with the motor case or the end plate. Since the end face receiving part for positioning the end part and the end face of the bearing is formed independently of each other, a jig for positioning the bearing is not required, moreover, there is no drawing step, and only the press work can be performed easily with high precision. Provided is a bearing fixing structure for a motor, which can be processed at a low cost and can be manufactured at low cost.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a configuration example of a motor having a bearing fixing structure to which the present invention is applied.

FIG. 2 is a front view of the motor case in FIG.

3 is a vertical cross-sectional view taken along the line 3-3 in FIG.

FIG. 4 is a partial vertical sectional view showing a bearing fixing structure of the motor of FIG.

FIG. 5 is a vertical sectional view showing an example of a conventional bearing fixing structure.

FIG. 6 is a vertical sectional view showing another example of a conventional bearing fixing structure.

[Explanation of symbols]

 10 motor case 11 bearing housing 12 end plate (mounting plate) 14 bearing housing 15 bearing 16 bearing 17 motor shaft 18 rotor 19 rotor magnet 20 exciting coil 21 exciting coil 26 bobbin 27 bobbin 28 motor terminal 29 motor terminal 32 outer peripheral receiving part 33 end surface Receiving part 35 Circuit board 37 Outer peripheral receiving part 38 End face receiving part 50 First phase stator unit 60 Second phase stator unit

Claims (3)

[Claims] 1. A bearing housing integrally formed with a motor case or an end plate, wherein an outer peripheral receiving portion for positioning the outer periphery of the bearing and an end surface receiving portion for positioning the end surface of the bearing are independently formed. Characteristic motor bearing fixing structure. 2. The bearing fixing structure for a motor according to claim 1, wherein the outer peripheral receiving portion and the end face receiving portion are formed by press working. 3. The bearing fixing structure for a motor according to claim 1, wherein the bearing is a ball bearing.