JPH08237902A - Motor bearing holder and manufacturing method thereof - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain a bearing holder for a motor that has high accuracy and low cost, and has a small load on the bearing, and a method for manufacturing the bearing holder. A bearing holder 2 for a motor, which is cylindrical and holds bearings 1 and 1'at both ends of an inner peripheral surface thereof. A plurality of bent portions 2a, which are integrally formed by cutting and raising, are formed on the outer peripheral surface of the bearing holder 2 in the longitudinal middle portion. In the bearing holder 2, at least a step of cutting a metal plate having a uniform thickness into a substantially rectangular shape and forming a substantially U-shaped cut in a flat surface portion, the metal plate is curled into a cylindrical shape, and both ends thereof are butted. And a step of bending a portion demarcated by the notch outward in the radial direction to form a bent portion. A pipe material may be used instead of the metal plate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor bearing holder applicable to, for example, a capstan motor of a tape recorder and a manufacturing method thereof.

[0002]

2. Description of the Related Art For example, in a capstan motor of a tape recorder, bearings are fitted into both end portions of a cylindrical bearing holder, and the rotary shaft of the motor is supported by these bearings. FIG. 5 shows an example of a motor used as a capstan motor. In FIG. 5, the substrate 35 has a hole 35a in the center, and the bearing holder 32 is inserted into this hole 35a. The bearing holder 32 is cylindrical and has a flange 32a on the outer peripheral surface in the center, and the lower end surface of the flange 32a is in contact with the substrate 35. A screw (not shown) is inserted in the collar portion 32a. The tip end of a screw (not shown) penetrates the collar portion 32a and is screwed into the substrate 35, and the bearing holder 32 is fixed to the substrate 35.

The flange portion 32a of the bearing holder 32 and the substrate 35.
A stator core 39 is attached to the outer peripheral surface of the lower side. The stator core 39 is formed by laminating a plurality of magnetic plates, and has a plurality of salient poles on the outer circumference. A coil 38 is wound around each salient pole.

At both ends of the inner peripheral surface of the bearing holder 32, bearings 31 and 31 'made of sintered oil-impregnated bearings are attached. The bearings 31, 31 'are ring-shaped and have a hole in the center. In addition, washers 42, 42 'are attached to the inner edge portions of both ends of the bearing holder 32.
The end surface of the bearing holder 32 inside is the bearing 31, 31 '.
Is in contact with the end surface of. A ring-shaped thrust bearing 43 is attached to the upper surface of the upper washer 42.

In the bearing holder 32, the thrust bearing 43,
The rotary shaft 33 is inserted through the central holes of the washer 42, the bearing 31, the bearing 31 ', and the washer 42'. A groove 33a is formed on the outer peripheral surface of the upper end portion of the rotating shaft 33.
A ring 44 is fixed to a. Also, the ring 44
The lower end surface of the shaft contacts the upper end surface of the thrust bearing 43, and the rotary shaft 33 is supported by the thrust bearing 43 in the thrust direction. Further, the rotating shaft 33 is the bearing 3
1, 31 'are supported in the radial direction, and as a result, the rotating shaft 33, which is a fixed member, is supported so as to be rotatable with respect to the bearing holder 32 and the substrate 35.

At the lower end of the rotary shaft 33, the rotor case 4
The center part of 0 is fixed. A drive magnet 41 is attached to the inner surface of the peripheral wall of the rotor case 40. The inner peripheral surface of the drive magnet 41 faces the outer peripheral surface of the stator core 39 with a constant gap.

When the coil 38 wound around the salient poles of the stator core 39 is energized, the drive magnet 41 is energized and the ring 44 attached to the rotary shaft 33 is energized.
While sliding on the thrust bearing 43, the rotor case 4
0, the rotary shaft 33 is rotationally driven.

Next, an example of another motor will be described. In FIG. 6, a substrate 55 is attached to the lower end surface of the frame 54. The frame 54 has a hole in the center, and a hole having a smaller diameter than the hole of the frame 54 is also formed in the center of the substrate 55. On the substrate 55, the bearing holder 52 is provided inside the hole of the central portion of the frame 54.
Is attached. The bearing holder 52 has a cylindrical shape and has a bent portion 52a at the lower end, and the bent portion 52a is the substrate 5
It is attached to 5. A hole 52b is formed at the tip of the bent portion 52a.

On the lower surface side of the substrate 55, a spacer 56 is attached to the edge portion of the hole in the central portion.
A stator core 59 is attached to the lower end surface of 6. The stay core 59 is configured by laminating a plurality of magnetic plates, has a salient pole on the outer circumference, and a coil 58 is wound around the salient pole.

Hole 52b of bent portion 52a of bearing holder 52
A screw 57 is inserted in the. The screw 57 is formed on the substrate 55.
Through the spacer 56 and screwed into the spacer 56,
2 and the spacer 56 are fixed to the substrate 55. Another screw (not shown) is inserted into the stator core 59 from the lower side, and this screw is screwed into the spacer 56, whereby the stator core 59 is fixed to the substrate 55.

Bearings 51 and 51 'made of sintered oil-impregnated bearings are press-fitted and fixed on the inner peripheral surface of the bearing holder 52. A rotary shaft 53 is inserted in the central hole of the bearing 51, 51 '. The center of the rotor case 60 is attached to the lower end of the rotary shaft 53 via a hub 62, and the drive magnet 61 is attached to the inner surface of the peripheral wall of the rotor case 60. The inner peripheral surface of the drive magnet 61 faces the outer peripheral surface of the stator core 59 with a certain gap. Therefore, when the coil 58 is energized, the drive magnet 61 is rotationally biased, and the rotor case 60 and the rotary shaft 53 are rotationally driven.

[0012]

In the motor shown in FIG. 5, since the bearing holder 32 is made of expensive zinc die casting or resin molding, the cost rises and the bearing holder 32 is expensive.
Since the bearing holder 32 cannot be formed with high accuracy, the bearings 51, 5
It also causes deterioration of the assembly accuracy of 1 '.

In order to solve the above drawbacks, a motor as shown in FIG. 6 has been proposed. The bearing holder 52 of the motor shown in FIG. 6 is made by curling a metal plate as shown in FIG.
It is formed by abutting both ends into a cylindrical shape. Pre-formed a protrusion on the bottom of the metal plate,
After curling the metal plate, the protruding portion is folded back to form the bent portion 52a, thereby forming the bearing holder 52 as shown in FIG. Although the bearing holder 52 formed of such a metal plate is low in cost, it has the bent portion 52a on the lower side, and by forming the bent portion 52a, the bearing 51 'is press-fitted. Since the shape of the lower inner peripheral surface of the bearing holder 52 is deformed into a polygonal shape as shown in FIG. 7B, the circularity of the upper side of the bearing holder 52 and the circularity of the lower side of the bearing holder 52 are different, and the bearings 51, 51 ′ Assembling accuracy will deteriorate. Further, since the bent portion 52a for attaching to the substrate 55 is provided at the lower end of the bearing holder 52, when the motor is constructed, the bearings 51, 5 are formed only on one surface of the substrate 55.
1'is arranged. With such a configuration, the bearings 51, 51 'cannot be arranged sufficiently apart from each other, and thus the load applied to the rotary shaft 53 by a pinch roller or the like (not shown) increases the load applied to the bearings 51, 51'.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and has a bearing holder for a motor that has both high accuracy and low cost, and can reduce the load on the bearing, and its bearing. It is intended to provide a manufacturing method.

[0015]

According to the first aspect of the present invention,
A bearing holder for a motor, which is cylindrical and holds a bearing at both ends of an inner peripheral surface, wherein a plurality of bent portions integrally formed by cutting and raising are formed at an intermediate portion in the longitudinal direction of the outer peripheral surface of the bearing holder. It is characterized by having. The invention according to claim 2 is characterized in that the inner circumferences of both end portions for holding the bearing are circular. The invention according to claim 3 is a method for manufacturing a bearing holder, wherein at least a metal plate having a uniform thickness is cut into a substantially rectangular shape, and a substantially U-shaped cut is formed in a flat surface portion, The method is characterized by including a step of curling the plate into a cylindrical shape and abutting both ends thereof, and a step of bending a portion defined by a notch outward in the radial direction to form a bent portion. According to a fourth aspect of the present invention, there is provided a method of manufacturing a bearing holder, which is defined by at least a step of forming a substantially U-shaped cut in an intermediate portion of an outer peripheral surface of a pipe material cut into a certain size, and the cut. It is characterized by at least including a step of bending the bent portion outward in the radial direction to form a bent portion.

[0016]

The bearing holder is fixed by attaching the bent portion to the frame of the motor or the substrate. The bent part is
Since the metal plate is formed in the middle part of the bearing holder made of curling or pipe material, it does not affect the shape (roundness) of both ends of the bearing holder to which the bearing is attached, and moreover, the bearing holder. Since the bearings attached to both ends of the motor can be disposed on both sides of the motor frame or the board to which the bent portion is fixed, the bearings are sufficiently spaced in a limited space.

[0017]

Embodiments of a motor bearing holder and a method of manufacturing the same according to the present invention will be described below with reference to the drawings. In FIGS. 1 and 2, a substrate 5 is attached to the lower end surface of the frame 4 of the motor. The frame 4 has a hole in the center thereof, and a hole having a smaller diameter than the hole of the frame is also formed in the center of the substrate 5. Board 5
The lower part of the bearing holder 2 is inserted into the hole at the center of the. The bearing holder 2 is formed in a cylindrical shape, and has a bent portion 2 formed by cutting and raising in an intermediate portion in the longitudinal direction.
It has a plurality of a. Since the bent portion 2a is cut and raised, the window portion 2d is necessarily formed in the middle portion of the bearing holder 2. A circular convex portion 2 is provided at the tip of the bent portion 2a.
b, and a hole 2c is formed in the center of the convex portion 2b. The bent portion 2a is located inside the hole at the center of the frame 4, and the lower end surface of the bent portion 2a is in contact with the edge of the hole of the substrate 5.

On the lower end surface side of the substrate 5, a spacer 6 is attached to the edge of the central hole, and a stator core 9 is attached to the lower end surface of the spacer 6. The stator core 9 is configured by laminating a plurality of magnetic plates, has salient poles on the outer circumference, and the coil 8 is wound around the salient poles.

A screw 7 is inserted into the hole 2c of the bent portion 2a of the bearing holder 2. The screw 7 penetrates the substrate 5 and is screwed into the spacer 6, so that the bearing holder 2 and the spacer 6 are fixed to the substrate 5. Further, another screw (not shown) is inserted through the stator core 9 from the lower side, and this screw is screwed into the spacer 6, whereby the stator core 9 is fixed to the substrate 5.

Bearings 1 and 1'made of sintered oil-impregnated bearings are press-fitted and fixed to the upper and lower ends of the inner peripheral surface of the bearing holder 2. Further, washers 12, 12 'are attached to the outer sides of the bearings 1, 1'at both ends of the bearing holder 2. Washer 12,
12 ′ has a hole in the center, and the surface of the washer 12 on the inner side of the bearing holder 2 abuts the upper end surface of the bearing 1,
The inner surface of the bearing holder 2 of 2'abuts on the lower end surface of the bearing 1 '. The rotating shaft 3 is inserted into the central holes of the washers 12, 12 'and the bearings 1, 1'. The center of the rotor case 10 is attached to the lower end of the rotating shaft 3 with the boss 16 interposed, and the drive magnet 11 is attached to the inner surface of the peripheral wall of the rotor case 10. The inner peripheral surface of the drive magnet 11 faces the outer peripheral surface of the stator core 9 with a certain gap. Therefore, by energizing the coil 8, the drive magnet 11 is rotationally biased, and the rotor case 10 and the rotary shaft 3 are rotationally driven.

Next, an example of a method of manufacturing the bearing holder 2 used in the above motor will be described. 1. First, a metal plate having a uniform thickness is cut into rectangular shapes at regular intervals to form a metal plate 13 as shown in FIG. 2 Next, a plurality of substantially U-shaped cuts 13d are formed from the center of the metal plate 13 in the vertical direction to the lower side. The metal plate 13 has a plurality of cantilevered separating portions 13a defined by the cuts 13d. 3 The protrusions 13b are formed by stamping the lower end of each separating portion 13a. Further, a punching process is performed on the central portion of each convex portion 13b to form a hole 13c. Convex part 1
The formation of 3b and the hole 13c may be performed in separate steps, or may be performed simultaneously in the same step. 4 The metal plate 13 is curled so that the protruding side of the convex portion 13b is the outer circumference, and both ends in the longitudinal direction (both left and right ends in FIG. 3) are butted to form a pipe-shaped intermediate member. The pipe-shaped intermediate member is formed such that the inner peripheries of both end portions in the vertical direction in the drawing are circular. 5. The bearing holder 2 as shown in FIG. 4 is formed by bending each separating portion 13a of the intermediate member from its root to the outside in the direction orthogonal to the central axis of the intermediate member. The window 2d is inevitably formed by bending the separating portion 13a.

The separating portion 13a shown in FIG. 3 becomes the bent portion 2a of the bearing holder 2 by curling and bending as described above. Similarly, the convex portion 13b becomes the convex portion 2b, and the hole 13c becomes the hole 2c.

According to the bearing holder of the above-mentioned motor, since it is formed by curling the metal plate 13, it is possible to contribute to cost reduction. Further, since the bent portion 2a is integrally formed by cutting and raising in the middle portion in the length direction, the bent portion 2a is formed in the roundness of the inner peripheral surfaces of both ends to which the bearings 1, 1'are attached. It is possible to assemble the bearings 1 and 1 ′ with high accuracy without adversely affecting them. Further, the bent portion 2a is provided at the middle portion in the length direction of the bearing holder.
Since it has a bearing 5, bearings 1, 2
1'can be arranged and the bearings 1, 1'can be arranged sufficiently far apart. Therefore, when the load of the pinch roller is applied to the rotating shaft 3, the bearing 1,
The load on the bearing 1'can be reduced, and the life of the bearings 1, 1'can be extended.

Although the bearing holder 2 is formed of a metal plate in the above embodiment, the present invention is not limited to this. Although not shown, a cantilevered separating portion is formed by forming a substantially U-shaped cut on the outer peripheral surface of the pipe material, and the separating portion is bent from the root to the outer peripheral side to form a bent portion, It is also possible to form the bearing holder in which the bent portion is attached to the frame of the motor and the bearing is held at the inner peripheral portions at both ends in the length direction of the pipe material.

Although the invention made by the present inventor has been specifically described based on the embodiments, the invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say. For example, although the notch formed on the flat surface portion of the metal plate or the outer peripheral surface of the pipe material is substantially U-shaped, it may be a notch having a right angle as shown in FIG. 3 (a), or FIG. 3 (b). It is also possible to make an arcuate notch as shown in FIG. That is, the shape is not particularly limited as long as one side is connected to the main body portion of the bearing holder and the notch is formed so as to define one end of the side from the other end.

[0026]

According to the present invention, since the bearing holder has a plurality of bent portions integrally formed by cutting and raising, etc., in the middle portion in the lengthwise direction of the outer peripheral surface of the bearing holder, the bent portions are the bearings. It is possible to assemble the bearing with high accuracy on both ends of the bearing holder without adversely affecting the roundness of both ends of the holder. Further, since the bearings can be arranged on both sides of the motor frame or the substrate as the center, it is possible to arrange the bearings sufficiently apart in a limited space.
For this reason, it is possible to reduce the load on the bearing caused by the radial load on the rotary shaft, and it is possible to extend the life of the bearing. Further, since the metal plate is curled or the bearing holder is formed of a pipe material, the manufacturing cost can be kept low.

[Brief description of drawings]

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

FIG. 2 is a cross-sectional view showing an embodiment of a bearing holder according to the present invention used in the same motor.

FIG. 3 is a plan view showing one step in the embodiment of the method for manufacturing the bearing holder of the motor according to the present invention.

FIG. 4 is a perspective view showing an embodiment of the above bearing holder.

FIG. 5 is a cross-sectional view showing an example of a motor having a conventional bearing holder.

FIG. 6 is a sectional view showing another example of a motor having a conventional bearing holder.

FIG. 7A is a perspective view of a bearing holder used in the same motor, and FIG. 7B is an enlarged plan view thereof.

[Explanation of symbols]

 1, 1'bearing 2 holder 2a bent portion

Claims (4)

[Claims] 1. A bearing holder for a motor, which is cylindrical and holds bearings at both ends of an inner peripheral surface, wherein the bearing holder is integrally formed by cutting and raising in an intermediate portion in a longitudinal direction of an outer peripheral surface of the bearing holder. A bearing holder for a motor, wherein a plurality of bent portions are formed. 2. The bearing holder for a motor according to claim 1, wherein the inner circumferences of both end portions holding the bearing are perfect circles. 3. A method for manufacturing a bearing holder for a motor, which comprises at least the following steps: (a) A metal plate having a uniform thickness is cut into a substantially rectangular shape, and a substantially U-shaped cut is formed in a flat surface portion. And (b) a step of curling the metal plate into a cylindrical shape and abutting both ends thereof, (c) a step of bending the portion demarcated by the notch radially outward to form a bent portion. 4. A method of manufacturing a bearing holder for a motor, which comprises at least the following steps: (a) a step of forming a substantially U-shaped cut in an intermediate portion of an outer peripheral surface of a pipe material cut into a certain size; (B) A step of forming a bent portion by bending the portion defined by the notch outward in the radial direction.