JPH089447Y2 - Pinch rollers and oil-impregnated bearings for pinch rollers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a pinch roller in a video tape recorder or the like, and more particularly to a bearing structure thereof.

[Prior Art] As shown in FIG. 3, the pinch roller (2) cooperates with the capstan motor shaft (4) to feed the tape running between them. In order to perform such a function smoothly and surely, the pinch roller (2) must be able to tilt along the capstan motor shaft (4). Therefore, conventionally, a deep groove type radial ball bearing (hereinafter simply referred to as a ball bearing)
It was attached to the shaft (8) so as to be tiltable using (6).

[Problems to be solved by the device]

In view of the fact that the use of ball bearings is an obstacle to cost reduction, it is an object of the present invention to provide a structure that does not use ball bearings and allows tilting of the pinch roller.

[Means for solving the problem]

This invention solves the above-mentioned problems by adopting an oil-impregnated bearing having the following shape instead of the ball bearing. That is, the oil-impregnated bearing has a generally hollow spindle shape, the central portion of the outer diameter has a linear shape parallel to the axis, and both sides of the central portion each have a tapered shape with a diameter reduced toward the end. . The inner diameter of the oil-impregnated bearing is straight at the center and crowned at both ends.

Use the oil-impregnated bearings that have been shaped as described above as they are.In addition, press the ones with straight inner diameter and cylindrical outer diameter consisting of the central part and the tapered both ends into the pinch rollers at appropriate places. The inner diameter may be given a predetermined crowning shape.

The pinch roller of the present invention includes a shaft fixed to a frame, a housing attached to the shaft via the oil-impregnated bearing, and a rubber roller fixed to the outer periphery of the housing.

[Action]

The pinch roller is pressed against the capstan motor shaft, and as a result, the tape is pressed between the rubber roller and the capstan motor shaft to feed the tape. At this time, since both ends of the inner diameter of the oil-impregnated bearing are crowned, the entire pinch roller easily follows the inclination of the capstan motor shaft, and the stable contact state with the capstan motor shaft is maintained over the entire length of the rubber roller. Reserved.

〔Example〕

 Hereinafter, a detailed description will be given with reference to the accompanying drawings.

As shown in FIG. 1, the pinch roller (20) has a shaft (24) fixed to a frame (28) and an oil-impregnated bearing (2).
A metal housing (22) having a rubber roller (21) on the outer periphery is attached via (3).

When the oil-impregnated bearing (23) having a straight inner diameter and tapered outer diameter ends as shown by the solid line in FIG. 2 is press-fitted into the housing (22), the solid line in FIG.
As shown by the chain line in FIG. 2, the inner diameter of the bearing is linear at the center and both ends of the center are crowned toward the ends.

The straight part in the center of the bearing leaves a proper clearance between it and the shaft (24) to apply radial runout during rotation.

In the axial direction, the stepped part of the shaft (24) and the oil-impregnated bearing (23)
Insert a washer (25) made of synthetic resin between and. Also,
Insert a washer (25) made of synthetic resin between the upper part of the oil-impregnated bearing (23) and the end cap (26).

After inserting the oil-impregnated bearing (23) into the shaft (24), the end cap (26) made of synthetic resin is attached to the end of the shaft (24).
Are fitted with an interference fit to position the oil-impregnated bearing (23). Provide an appropriate axial clearance between the end cap (26) and the washer (27).

The interference fit between the housing (22) and the oil-impregnated bearing (23) allows a pull-out force of 10 kgf, and can hold the pinch roller (20) at an appropriate position in the axial direction.

The pinch roller (20) having the above-described structure is attached to a proper position of a main body such as a video tape recorder by the shaft (24) and the frame (28), and the rubber roller (2
1) extends parallel to the capstan motor shaft (4) (see Fig. 3). During use, the pinch roller (20) is pressed against the capstan motor shaft (4), so that the rubber roller (21) presses a tape (not shown) between it and the capstan motor shaft (4). ,
Can be sent. Since both ends of the inner diameter of the oil-impregnated bearing (23) are crowned, the entire pinch roller (20) easily follows the inclination of the capstan motor shaft (4) and the entire length of the rubber roller (21). A stable contact state with the capstan motor shaft (4) is secured.

[Effect of device]

As described above, in the present invention, the shape of the oil-impregnated bearing is devised so that the pinch roller can be tilted with respect to the shaft. Therefore, the pinch roller easily follows the tilt of the capstan motor shaft and the total length of the rubber roller is increased. A stable contact state with the capstan motor shaft can be secured over the entire range, and there is no concern that the function of the pinch roller is deteriorated due to uneven contact or the like. Therefore, according to this invention, a cheaper oil-impregnated bearing can be adopted in place of the conventional ball bearing, so that the cost of the pinch roller can be reduced.

[Brief description of drawings]

1 is a sectional view of a pinch roller, FIG. 2 is a sectional view of an oil-impregnated bearing, and FIG. 3 is a sectional view showing a capstan motor and a conventional pinch roller. 4: Capstan motor shaft 20: Pinch roller 23: Oil bearing 21: Rubber roller 22: Housing 24: Shaft

Claims (3)

[Scope of utility model registration request] 1. A shaft fixed to a frame, a housing having a rubber roller on its outer periphery, and an oil-impregnated bearing interposed between the shaft and the housing, the oil-impregnated bearing being press-fitted into the housing, By having the inner diameter of the oil-impregnated bearing has a straight central portion and a crowning-shaped both end portion with a clear lance left between the shaft and the shaft,
A pinch roller which is tiltable with respect to the shaft. 2. A pinch roller including a shaft fixed to a frame, a housing having a rubber roller on the outer periphery thereof, and an oil-impregnated bearing interposed between the shaft and the housing, the inner diameter of which is a clearance between the shaft and the shaft. An oil-impregnated bearing for a pinch roller having a straight central portion and crowning-shaped both ends that gradually expand in diameter toward the ends. 3. A pinch roller including a shaft fixed to a frame, a housing having a rubber roller on its outer periphery, and an oil-impregnated bearing interposed between the shaft and the housing, wherein the inner diameter is cylindrical and the outer diameter is cylindrical. The central part of the inner diameter is linear with the clearance left between it and the shaft, and both ends gradually expand toward the end by press fitting into the housing. An oil-impregnated bearing for pinch rollers that has a crowning shape with a diameter.