JPH0684763U - Bearing device for motor - Google Patents

Abstract

(57) [Summary] [Purpose] Without damaging the insertion hole of the oil-impregnated bearing,
Moreover, a tapered insertion hole with good dimensional accuracy is obtained. [Structure] In a cylindrical bearing 10 having an insertion hole 11 for supporting a rotating shaft, a ring-shaped sleeve 13 having an inner diameter smaller than the outer diameter of the bearing 10 is press-fitted on one end side, and the insertion hole 11 is The inner diameter on one end side is formed in a substantially tapered shape smaller than the inner diameter on the other end side.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a bearing device for a motor, and more particularly to a bearing device suitable for a capstan motor configured to pivotally support a shaft to which a lateral pressure load is applied.

[0002]

[Prior art]

 Conventionally, this type of motor bearing device has been mainly used for a capstan motor for driving and driving a magnetic tape such as a video tape recorder. This capstan motor has a rotating shaft that serves as a capstan shaft, and lateral pressure is applied laterally by a pinch roller being pressed against the rotating shaft, as is well known. Since the rotating shaft bends due to lateral pressure, for example, when the insertion hole of the sintered oil-impregnated bearing that rotatably supports the rotating shaft is constant at the front and rear ends, the rotating shaft is unidirectionally contacted with the front end. The point contact or line contact. In this state, the problem that the rotary shaft does not rotate smoothly occurs. Therefore, in some cases, the rotary shaft was rotated for a predetermined time to perform aging to cut the oil-impregnated bearing until a surface contact condition was obtained.

However, since it takes a considerably long time to age until the rotary shaft and the oil-impregnated bearing come into surface contact with each other, there is a problem that productivity is reduced. In order to solve this problem, as shown in FIG. 4, an oil-impregnated bearing 3 having an insertion hole 2 through which the rotary shaft 1 is inserted is provided, and the inner diameter A on the front end side of the insertion hole 2 is changed to the inner diameter B on the rear end side. There has been proposed a device for forming a larger tapered shape to eliminate the uneven contact of the rotating shaft 5.

As described above, by the configuration in which the insertion hole 2 of the oil-impregnated bearing 3 is formed in a taper shape, when the rotary shaft 5 is bent due to lateral pressure, the insertion hole 2 and the rotation shaft 1 of the oil-impregnated bearing 1 are initially formed. Since the surface contact is likely to occur, the aging time can be shortened.

[0005]

However, in the above bearing device for a motor, when the insertion hole of the oil-impregnated bearing is formed in a tapered shape, a taper pin having a tapered outer diameter is press-fitted into the insertion hole in advance. The method of manufacturing by this is adopted. However, when the taper pin is press-fitted as described above, the inner surface of the insertion hole of the oil-impregnated bearing may be damaged, and the desired performance as a bearing is degraded, which poses a problem in practical use.

The present invention has been made to solve such a problem, and a tapered insertion hole having good dimensional accuracy is obtained without damaging the insertion hole of the oil-impregnated bearing. An object of the present invention is to provide a bearing device for a motor that can be used.

[0007]

[Means for Solving the Problems]

 According to the present invention, in a cylindrical bearing having an insertion hole for rotatably supporting a rotating shaft, a ring-shaped sleeve having an inner diameter smaller than the outer diameter of the bearing is press-fitted at one end side, and the insertion hole is It is characterized in that the inner diameter on one end side is formed in a substantially tapered shape smaller than the inner diameter on the other end side.

[0008]

[Action]

 By press-fitting the sleeve onto the outer circumference of the one end side of the bearing, the inner diameter of the one end side is reduced, and thus the inner diameter of the other end side is gradually reduced toward the one end side to form a substantially tapered shape. Therefore, since the inner surface of the bearing is not subjected to any processing, there is no risk of damage or the like, and moreover, there is no dimensional change due to springback and the dimensional accuracy is good.

[0009]

【Example】

 Embodiments of a motor bearing device according to the present invention will be described below with reference to the drawings. In FIG. 1, an oil-impregnated bearing 10 formed of a cylindrical oil-impregnated bearing or the like has an insertion hole 11 formed at the center in the axial direction. Further, a press-fitting portion 12 having a slightly smaller diameter is formed on the outer periphery at the one end side on the lower side of the drawing. The press-fitting portion 12 may be provided at the time of molding the oil-impregnated bearing 10 or may be provided later by lace processing. Further, the inner surface of the insertion hole 11 is finished with good surface accuracy by being subjected to a normal sizing process. A sleeve 13 is press-fitted into the press-fitting portion 12.

The sleeve 13 is made of, for example, brass having a rigidity equal to or higher than that of the oil-impregnated bearing 10, and is formed in a ring shape as shown in FIG. The press-fitting margin between the sleeve 13 and the press-fitting portion 12 of the oil-impregnated bearing 10 is set within the range of 10 to 40 μm. Then, by press-fitting the sleeve 13 into the press-fitting portion 12, one end side of the oil-impregnated bearing 10 is compressed, and as a result, the inner diameter A1 on one end side of the insertion hole 11 is smaller than the inner diameter B1 on the other end side by 10 to 40 μm. It is formed in a substantially tapered shape. After the taper is formed, the sleeve 13 prevents the oil-impregnated bearing 10 from springing back, so that the accuracy of the tapered insertion hole 11 is maintained.

The degree of taper of the insertion hole 11 as described above can be appropriately set depending on the press-fitting margin with the sleeve 13, and can also be arbitrarily changed depending on the material of the oil-impregnated bearing 10 and the like. Further, it is desirable that the degree of such taper be appropriately set according to the degree of bending of the rotary shaft 5 due to the aforementioned lateral pressure.

The above bearing device is applied to the capstan motor shown in FIG. That is, the oil-impregnated bearing 10 similar to that described with reference to FIG. 1 is fixed to the distal end side of the hollow portion 21 of the housing 20 by press fitting, and the ball bearing 30 is fixed to the lower end side to support the rotary shaft 22. I am trying.

One end side of the rotating shaft 22 is fixed to a flat rotor yoke 32 formed in a substantially dish shape by protruding from a lower ball bearing 30 and a bush 31. Further, an annular drive magnet 33 magnetized with multiple poles is fixed to the inner surface of the rotor yoke 32. Further, a circuit board 35 also serving as a stator yoke is fixed to a flange 34 integrally formed on the outer periphery of the housing 10, and a plurality of drive coils 36 face the drive magnet 33 on the circuit board 35. Are arranged in a ring. On the other hand, the other end of the rotary shaft 15 projects from the bearing 12, and a pinch roller 37 that moves forward and backward is pressed against the rotary shaft 22. When the rotary shaft 22 rotates, a magnetic tape (not shown) is applied. Run at a constant speed.

It should be noted that the above-described embodiment is merely an example, and the bearing device is not limited to the capstan motor and may be used for other types of motors such as a streamer spindle motor, for example. Various changes can be made without departing from the range.

[0015]

[Effect of device]

 As is clear from the above description, according to the bearing device for a motor of the present invention, the inner diameter of one end side is compressed by pressing the sleeve into the outer periphery of the one end side of the bearing, so that the one end side is compressed to the other end side. It can be formed in a substantially tapered shape smaller than the inner diameter of. Therefore, since the inner surface of the bearing is not processed at all, there is no risk of damage or the like, and there is an advantage that the dimensional accuracy can be improved since the dimensional change due to springback does not occur.

[0016]

[Brief description of drawings]

FIG. 1 is a sectional view showing a bearing device for a motor according to the present invention.

FIG. 2 is an exploded sectional view of the above bearing.

FIG. 3 is a half sectional view showing a capstan motor using the above bearing device.

[Explanation of symbols]

 10 Oil-impregnated bearing 11 Insertion hole 12 Press-fitting portion 13 Sleeve 22 Rotating shaft

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[Procedure amendment]

[Submission date] October 29, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a sectional view showing a bearing device for a motor according to the present invention.

FIG. 2 is an exploded sectional view of the above bearing.

FIG. 3 is a half sectional view showing a capstan motor using the above bearing device.

FIG. 4 is a related cross-sectional view showing a conventional bearing device.

[Explanation of symbols] 10 oil-impregnated bearing 11 insertion hole 12 press-fitting portion 13 sleeve 22 rotating shaft

Claims (1)

[Scope of utility model registration request] 1. A cylindrical bearing having an insertion hole for rotatably supporting a rotating shaft, wherein a ring-shaped sleeve having an inner diameter smaller than the outer diameter of the bearing is press-fitted into one end of the bearing. By this press-fitting, the insertion hole is formed into a substantially tapered shape in which the inner diameter on one end side is smaller than the inner diameter on the other end side.