JPH0644374U - motor - Google Patents

Abstract

(57) [Summary] [Object] To obtain a motor capable of preventing oil bleeding from an oil-impregnated bearing from entering between a pulley and a belt without increasing the thickness of the motor. A motor having a rotary shaft 2 supported by an oil-impregnated bearing 1 and a pulley 4 fixed to the rotary shaft 2 and having a belt 3 disposed on a surface of the pulley 4 facing the oil-impregnated bearing 1. The edge portion 5 was formed over the entire circumference. The edge portion 5 can prevent the oil from spreading.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a motor, and more particularly to an oil stop mechanism for a thin motor.

[0002]

[Prior art]

 Conventionally, an oil-impregnated bearing may be used as a bearing used for a motor. Since oil-impregnated bearings can be made smaller in size than bearings such as ball bearings, they are mainly used in thin motors and the like.

A conventional example of a motor using oil-impregnated bearings will be described with reference to the drawings. In FIG. 5, the oil-impregnated bearing 21 is attached to a bearing holder of a motor case (not shown), and the rotary shaft 22 is rotatably supported by the oil-impregnated bearing 21. A drum-shaped pulley 24 is attached to the upper end of the rotary shaft 22, and a belt 23 is hung on a circumferential groove of the pulley 24. When the rotary shaft 22 rotates, its power is transmitted to other members by the pulley 24 and the belt 23.

[0004]

[Problems to be solved by the device]

 As shown in FIG. 6, oil 26 oozes from the oil-impregnated bearing 21. The oil 26 bleeding from the oil-impregnated bearing 21 is transmitted to the pulley 24 via the rotary shaft 22, and is spread toward the outer periphery of the pulley 24 by the centrifugal force generated when the pulley 24 rotates. As a result, the pulley 24 and the belt 23 are adversely affected by slipping each other. A washer (not shown) was sometimes inserted between the oil-impregnated bearing 21 of the rotary shaft 22 and the pulley 24 in order to block the oil 26 oozing out from the oil-impregnated bearing 21. However, even if a washer was used, the oil 26 could not be completely shut off.

The present invention has been made to solve the above problems, and it is possible to prevent the oil bleeding from the oil-impregnated bearing from entering between the pulley and the belt without increasing the thickness of the motor. An object is to provide a motor that can be prevented.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention is a motor provided with a rotary shaft supported by an oil-impregnated bearing 1 and a pulley fixed to the oil-impregnated shaft and provided with a belt. It is characterized in that an edge portion is formed over the entire circumference on the surface of the facing pulley.

[0007]

[Action]

 The oil bleeding from the oil-impregnated bearing travels along the rotating shaft to reach the pulley, and the centrifugal force generated by the rotation of the pulley spreads it toward the outer circumference of the pulley, but the oil is formed over the entire circumference of the pulley surface. It is blocked by the edge and does not wrap around where the belt is hung.

[0008]

【Example】

 Embodiments of a motor according to the present invention will be described below with reference to the drawings. In FIG. 1, a drive magnet 7 is attached to the inner surface of the peripheral wall of a motor frame 6 having a cylindrical shape with a bottom. An end plate 14 is fitted and fixed to the open end of the motor frame 6. The end plate 14 has a circular shape and has a recess in the center, and holders 13 and 13 formed of resin or the like are attached to the end plate 14 in the thickness direction so as to sandwich the recess. Terminals 9 and 9 for power supply are respectively passed through and fixed to the holders 13 and 13, respectively. Further, the base ends of brush springs 8 extending in a direction orthogonal to a rotation axis, which will be described later, are attached to the terminals 9, 9. A slit is formed at the tip of each brush spring 8 and is divided into a plurality of slits.

In the drawing corresponding to the bottom plate of the motor frame 6, a hole is formed by punching in the center of the upper end plate, and this hole and the central recess of the end plate 14 are respectively impregnated with oil. Bearings 1, 1'are attached. A rotary shaft 2 is inserted into the central holes of the oil-impregnated bearings 1 and 1 '. The rotary shaft 2 is rotatably supported by the oil-impregnated bearings 1 and 1 ′ with respect to the motor frame 6 and the end plate 14.

A rotor core 10 is attached to a substantially central portion of the rotary shaft 2 in the longitudinal direction. The rotator core 10 is formed by stacking a plurality of core bodies. The rotor core 10 has a plurality of salient poles on its outer peripheral portion, and a winding wire 11 is wound around each salient pole of the rotor core 10. The outer peripheral surface of the rotor core 10 faces the inner peripheral surface of the magnet 7 mounted inside the peripheral wall of the motor frame 6 with a gap.

In FIG. 1, a commutator 15 is attached to a portion of the rotary shaft 2 below the rotor core 10. The commutator 15 has a cylindrical shape, and a plurality of partially cylindrical segments are attached to the surface thereof. The tip of the brush spring 8 is in contact with the surface of the commutator 6 by the elastic force of the brush spring 8. When the winding 11 is energized through the terminal 9, the brush panel 8 and the commutator 15, the rotor core 10 is energized and the rotating shaft 2 is driven to rotate.

In FIG. 1, a pulley 4 is fixed to one end of a rotary shaft 2 protruding upward from an upper end of a motor frame 6 by press fitting or the like. The pulley 4 has a peripheral groove, and the belt 3 for transmitting power to other members is hung on the peripheral groove. At the edge of the surface of the pulley 5 facing the oil-impregnated bearing 1, as shown in detail in FIG. 2, an edge 5 sharply pointed downward is formed over the entire circumference.

When the oil-impregnated bearing 1 is used as the bearing as in the above-described embodiment, the oil 12 oozing out from the oil-impregnated bearing 1 reaches the bottom surface of the pulley 4 as shown in FIG. The generated centrifugal force spreads toward the outer circumference of the pulley 4. However, since the edge portion 5 of the bottom of the pool 4 is formed with a sharply pointed edge portion 5 over the entire circumference, the advance of the oil 12 reaching the edge portion 5 is blocked by the edge portion 5. The oil 12 whose movement is blocked by the edge portion 5 is held by the surface tension and becomes spherical.

Here, a method of forming the edge portion 5 on the pulley 4 will be described. When the pulley 4 is made of metal such as brass, it is generally chamfered so that no burrs remain on the peripheral edge. However, if this chamfering process is omitted, the above-mentioned burr can be left as the edge portion 5. Alternatively, the edge portion 5 can be formed by pressing a pressing roller against the outer peripheral edge portion of the pulley 4 to deform it. Since the resin pulley 4 cannot be cut, it must be integrally molded with a mold, but it is difficult to form the molding portion of the edge portion 5 on the molding die. Therefore, if the mating die is used to form the pulley 4 so that the parting line of the mating die is exactly on the edge portion 5 of the pulley 4, the tip is sharp and sharp even if the material is resin. The edge part 5 can be formed.

As shown in FIG. 2, the edge portion of the pulley does not necessarily need to be clearly raised in the direction away from the circumferential groove, and may have a sharp corner. If the chamfering is C0.1 or less, that is, the chamfered portion is 0.1 mm or less, the desired effect can be obtained.

The number of the edge portions 5 is not limited to one, and if the plurality of edge portions 5 are combined to block the oil, the effect is further enhanced. FIG. 3 shows an example thereof, and a step may be formed on the end surface of the pulley 4 along a concentric circle, and edge portions 5 and 5 may be formed on the step portion and the outer peripheral edge portion of the pulley 4, respectively. Alternatively, as shown in FIG. 4, a plurality of concentric grooves 16 may be formed on the end surface of the pulley 4, and the edges 5 may be formed on the inner peripheral edge of each groove 16.

[0017]

[Effect of device]

 According to the present invention, since the edge portion is formed over the entire circumference of the surface of the pulley of the motor that faces the oil-impregnated bearing, the oil is blocked without using a washer or the like that would thicken the body of the motor. In addition, since the oil does not reach the portion of the pulley where the belt is hung, slippage between the pulley and the belt can be prevented.

[Brief description of drawings]

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

FIG. 2 is a sectional view showing a main part of the embodiment.

FIG. 3 is a sectional view showing a main part of another embodiment of the motor according to the present invention.

FIG. 4 is a sectional view showing a main part of another embodiment of the motor according to the present invention.

FIG. 5 is a schematic view showing an example of a conventional motor.

FIG. 6 is an enlarged cross-sectional view showing a main part of a conventional motor.

[Explanation of symbols]

 1 Oil-impregnated bearing 2 Rotating shaft 3 Belt 4 Pulley 5 Edge

Claims (1)

[Scope of utility model registration request] 1. A motor comprising a rotary shaft supported by an oil-impregnated bearing and a pulley fixed to the oil-impregnated bearing and having a belt disposed thereon. A motor formed by forming an edge portion over the entire length.