JP3003308U - Bearing support structure for rotating electrical machines - Google Patents

Abstract

(57) [Summary] [Purpose] The object is to obtain a simple bracket structure for directly supporting a bearing on a plate-shaped bracket attached to the yoke of a stepping motor. In a rotary electric machine in which a plate-shaped bracket (18) is provided on a side surface of a yoke (12) forming a stator, and a rotor (20) is supported by a bearing (20) supported by the bracket (18), the rotor (16) is supported at the center of the bracket (18). The support hole 26 is provided, and a stopper claw 28 extending in the axial direction is provided on the inner periphery of the support hole 26, and a plurality of radial claws 30 bent in the axial direction from the peripheral edge of the support hole 26.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement in a rotary electric machine including a relatively small stepping motor used in office electronic equipment, and more particularly to a support structure for a bearing that supports a rotor.

[0002]

[Prior art]

 Generally, in a stepping motor, a plate-shaped bearing support plate is attached to an end surface of a cylindrical yoke, and a bearing that supports a rotor is supported by the plate-shaped bearing support plate. (For example, Japanese Patent Laid-Open No. 3-112356).

However, if an attempt is made to support the bearing in the hole provided in such a plate member, the supporting surface for mounting the bearing is too small, and the rigidity of the bearing supporting portion becomes low. Therefore, as shown in FIG. 5 and FIG. 6, the bearing housing H is attached to the bearing support plate P by caulking to reinforce it, and the bearing B is supported through it, or the bearing support plate P is burred. It is also performed that the bearing shaft is machined into a cylindrical shape and a bearing hole is punched in the side surface to directly support the output shaft S in the shaft hole of the bearing housing H.

[0004]

[Problems to be solved by the device]

 However, if another bearing housing is attached to the bearing support plate and a bearing is provided on it, or if the bearing housing itself is made of a material with excellent lubricity, the number of parts that make up the rotating electric machine increases and they are combined. Requires an assembly process to do so. Alternatively, there is a problem that the cost of production will be greatly increased because expensive materials will be required for the parts. In addition, the bearing hole made by burring can be positioned in the radial direction, but it cannot be positioned in the thrust direction. In addition, in any of the above structures, manufacturing is too difficult or high accuracy is difficult to maintain as a supporting structure for supporting an ultra-compact bearing used for a stepping motor with a small diameter of about 20 to 30 mm. was there.

[0005]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention provides a rotary electric machine in which a plate-shaped bracket 18 is provided on a side surface of a yoke 12 that forms a stator, and a rotor 20 is supported by a bearing 20 supported by the bracket 18. A support hole 26 for supporting the rotor 16 is provided in the center of the support hole 26, a stopper claw 28 extending in the axial direction on the inner circumference of the support hole 26, and a plurality of radial claws bent from the peripheral edge of the support hole 26 in the axial direction. And 30 are provided.

[0006]

[Action]

 The radial claw 30 and the stopper claw 28 are both projected from the inner circumference toward the axial direction when punching out the support hole 26 from the steel plate. Only the radial claw 30 is further bent in the axial direction. There is. Each of the bent claws of the radial claw 30 has an arc-shaped cross section, and a bearing hole 31 is formed on the inner surface thereof. When the outer circumference of the bearing 20 is press-fitted into the bearing hole 31, the bearing 20 is guided by the inner surface of the radial pawl 30 to move in the axial direction, and is pushed to a position where it abuts on the stopper pawl 28 and is held at a predetermined position.

[0007]

【Example】

 The present invention will be described below with reference to the illustrated embodiments. In the figure, 10 is a stepping motor adopting the bearing device according to the present invention, and has a so-called claw pole type yoke 12. That is, in the stepping motor 10, two pairs of annular yokes 12, 12 are arranged side by side in the axial direction to form a stator 14, and brackets 18 are attached to both end surfaces of the stator 14 by adhesion or adhesion. Reference numeral 16 is a rotor supported by the bracket 18.

The yoke 12 forming the stator 14 is formed by arranging an annular steel disc and two halves each having a claw extending in the axial direction from the inner and outer peripheries thereof so as to face each other. The exciting coil 22 is sandwiched between them. The exciting coil 22 is composed of an exciting winding 22a made by winding an electric wire and a bobbin 22b made of an insulating material to hold the exciting winding 22a.

The rotor 16 arranged inside the stator 14 includes an output shaft 24 and a permanent magnet supported by the output shaft 24. That is, a cylindrical magnet rotor 34 is supported on the output shaft 24 via a sleeve 32. As is well known, the magnet rotor 34 is magnetized with a plurality of magnetic poles at a predetermined pitch in the circumferential direction. ing.

The bracket 18 that supports the rotor 16 is composed of a flange bracket 18a and a shield bracket 18b, and bearings 20 and 20 are provided on them, respectively. The flange bracket 18a supporting the front bearing 20 is arranged on the side where the output shaft 24 projects, and is provided with four mounting holes 18c for mounting the stepping motor 10 to other members. Reference numeral 11 is a lead wire for connecting the stepping motor 10 to a control circuit (not shown). It should be noted that the bearing 20 is not limited to the illustrated ball bearing, and an oil-free plain bearing (or bush) can also be used and has been widely used conventionally.

The characteristic structure according to the present invention will be described below. As described above, the brackets 18a and 18b of the stepping motor 10 are attached to both side surfaces of the yoke 12 by adhesion or adhesion. Both of the brackets 18a and 18b are formed by pressing a thin steel plate into an annular shape, and a support hole 26 for the output shaft 24 forming the rotor 16 is formed in the center thereof.

Inside the support hole 26, there are three stopper claws 28 extending axially from the support hole 26, that is, from the inner surface of the support hole 26 toward the axial direction of the output shaft 24, and bent from the root. And three radial claws 30 extending axially from the edge of the support hole 26 are provided. The stopper claw 28 and the radial claw 30 are formed by pressing a steel plate as a material. That is, the radial claw 30 and the stopper claw 28 both protrude from the inner circumference toward the axial direction when punching out the support hole 26 from the steel plate, and only the radial claw 30 further bends it in the axial direction. It was made. The radial claw 30 may include the punching step and the axial bending step in two steps, or may be processed in one step at the same time.

Each of the radial claws 30 has a circular arc-shaped cross section, and a plurality of the radial claws 30 form a notched bearing hole 31. The diameter of the bearing hole 31 is equal to the outer diameter of the bearing 20 to be supported. It is set to be approximately equal or smaller. When the outer circumference of the bearing 20 is press-fitted into the bearing hole 31, the bearing 20 is guided by the inner surface of the radial pawl 30 and moves in the axial direction, and eventually contacts the stopper pawl 28 and is held at that position. The number of both claws 28 and 30 is not limited to three, and one stopper claw is sufficient, and it is necessary that there be a plurality of radial claws 30.

On the other hand, as is apparent from FIGS. 1 and 2, a disc-shaped resin label 19 is attached to the surface of the shield bracket 18b after the bearing 20 is assembled. The label 19 has a function of closing a hole opened in the center of the bracket 18. This prevents dust and the like from entering the stepping motor 10 such as the bearing 20 from the outside, which is a measure against dust.

Although the above embodiment has described the stepping motor 10, the present invention is not limited to this, and can be used for other small electric motors and pulse generators, and is included in the technical scope thereof. To be done.

[0016]

[Effect of device]

 As described above, according to the present invention, since the bearing 20 supporting the output shaft 24 is directly supported by the bracket 18, the above-mentioned conventional bearing housing is not required, so that the number of parts is small and the structure is simple. Become. Further, since the work for assembling the bearing housing to the bracket 18 is unnecessary, the manufacturing process can be shortened. Further, since the radial claw 30 and the stopper claw 28 are metallurgically integrated with the bracket 18 and are simultaneously molded at the time of molding, the strength is excellent and the man-hours for production are greatly increased. It has no productivity and is excellent in productivity. Therefore, the effect of reducing the production cost of the rotating electric machine is remarkable.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of a rotary electric machine showing an embodiment of the present invention.

FIG. 2 is a back view showing an annular bracket which is a main part thereof.

FIG. 3 is a sectional view taken along the line III-III.

FIG. 4 is a side view thereof.

FIG. 5 is a sectional view of a main part showing a conventional bearing structure.

FIG. 6 is a sectional view of a main part showing another conventional bearing structure.

[Explanation of symbols]

 10 ... Stepping motor 11 ... Lead wire 12 ... Yoke 14 ... Stator 16 ... Rotor 18 ... Bracket 18a ... Flange bracket 18b ... Shield bracket 18c ... Mounting hole 19 ... Label 20 ... Bearing 22 ... Excitation coil 22a ... Excitation winding 22b ... Bobbin 24 ... Output shaft 26 ... Support Hole 28 ・ ・ ・ ・ Stopper claw 30 ・ ・ ・ Radial claw 31 ・ ・ ・ ・ Bearing hole 32 ・ ・ ・ ・ Sleeve 34 ・ ・ ・ ・ Magnet rotor

Claims (1)

[Scope of utility model registration request] 1. A rotary electric machine in which a plate-shaped bracket (18) is provided on a side surface of a yoke (12) which forms a stator, and a rotor (20) is supported by a bearing (20) supported by the bracket (18), and the rotor (16) is supported at the center of the bracket (18). And a plurality of radial claws 30 bent from the peripheral edge of the support hole 26 in the axial direction. Bearing support structure.