JPH07282492A - Pinch roller - Google Patents

Abstract

PURPOSE:To maintain the tape traveling stability by making either of end parts of a sliding surface of an inner diameter part of a sliding bearing with a pinch roller supporting shaft approximately coincide with the center of a pinch roller in its width direction. CONSTITUTION:A leg of a perpendicular from a sliding part C between the sliding bearing 6 press-fitted into a cylindrical holder 3 and a pinch roller supporting shaft 2 down to an outer circumferential part of the pinch roller is coincident with the center of the pinch roller in the width direction. Then, even when the pinch roller supporting shaft 2 is more or less inclined in the direction of A, contact pressure between the outer circumferential part of the pinch roller and a capstan shaft 7 is distributed symmetrically to the center of the pinch roller in the width direction. As a result, a changing state of the tape height in the tape width direction before and after press-contacting the pinch roller against the capstan shaft 7 is ameliorated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pinch roller used in a magnetic recording / reproducing apparatus or the like.

[0002]

2. Description of the Related Art In recent years, in order to stabilize the tape speed by improving the accuracy of magnetic recording / reproducing devices, the importance of improving the accuracy of the pinch roller is increasing, and an inexpensive pinch roller is provided. Above all, cost reduction of the pinch roller cannot be avoided. Regarding the cost reduction of the pinch roller, various shapes have been studied so far. Among them, as the bearings used for the pinch rollers, widely used are ball bearings that have been conventionally used, and sliding bearings made of resin which are simple in structure and inexpensive.

An example of the pinch roller described above will be described below with reference to the drawings. FIG. 5 shows a side cross section of a conventional pinch roller. In FIG. 5, 13 is a cylindrical holder, and a cylindrical elastic body 14 made of, for example, rubber is integrally attached to the outer periphery of the cylindrical holder 13 by baking or the like. A resin slide bearing 16 is press-fitted into the inner circumference of the cylindrical holder 13, and the slide bearing 16 is rotatably held by a polyslider 15 mounted on the pinch roller support shaft 11.
The stopper 12 fixed to the pinch roller support shaft 11 penetrating the inner diameter part of the shaft prevents the displacement in the thrust direction. The sliding bearing 16 made of resin is press-fitted so that the center of the sliding surface with the pinch roller support shaft 11 in the width direction coincides with the center of the pinch roller in the width direction, and the sliding bearing press-fitted in the cylindrical holder 13 is pressed. A clearance is provided between the bearing 16 and the pinch roller support shaft 11, and play is generated between the pinch roller support shaft 11 and the slide bearing 16 by the clearance, which is the self-aligning amount. 17 is a capstan shaft,
18 is a tape.

The operation of the conventional pinch roller constructed as above will be described below. Since the tape 18 is transferred by the cooperation of the pinch roller and the capstan shaft 17, when the pinch roller is pressed against the capstan shaft 17 with a predetermined force by sandwiching the tape 18, the tape 18 is not attached to the capstan shaft 17 for some reason. Even if the pinch roller support shafts 11 are in a non-parallel state, the pinch roller is pressed against the inclination of the capstan by the self-aligning action, so that the tape transfer can be realized. Also, by using a resin slide bearing instead of a ball bearing,
The cost can be reduced compared to the ball bearings used conventionally.

[0005]

However, the conventional pinch roller having the above-mentioned structure has the following problems.

In the pinch roller having the above-mentioned structure, as compared with the conventional pinch roller using a ball bearing, the pinch roller support shaft 11 serves as the capstan shaft 17 in the direction of the X direction in FIG. When tilted with respect to each other, the contact between the pinch roller support shaft 11 and the slide bearing 16 always occurs in the central portion of the slide bearing. Therefore, the contact pressure between the capstan shaft 17 and the pinch roller always has a symmetrical distribution with respect to the center of the pinch roller in the width direction. On the other hand, when the pinch roller support shaft 11 is tilted in the direction having the Y direction as a rotation axis in FIG. 5, that is, in the direction of arrow A, while the capstan shaft 17 and the pinch roller support shaft 11 are parallel, the capstan shaft 17 The contact pressure between the pinch roller and the pinch roller has a symmetrical distribution with respect to the center of the pinch roller in the width direction. However, if the pinch roller support shaft 11 is slightly inclined with respect to the capstan shaft 17, the pinch roller support shaft 11 and the slide bearing 16 come into contact with each other at the upper end portion or the lower end portion of the slide bearing sliding surface. Therefore, due to the contact, the contact pressure between the pinch roller and the capstan shaft 17 is not symmetrical with respect to the center of the pinch roller in the width direction, and the tape height in the tape width direction around the capstan shaft 17 is pressed by the pinch roller. It becomes a cause of easy change before and after. Therefore, it is necessary to control the inclination accuracy of the pinch roller support shaft 11 with high accuracy so that the pinch roller support shaft 11 does not tilt in the direction A in FIG. It had a problem of causing ups.

In view of the above problems, it is an object of the present invention to provide a pinch roller which improves the stability of tape running by using the bearing of the present invention as the bearing of the pinch roller.

[0008]

In order to solve the above problems, a pinch roller of the first invention has a slide bearing rotatably supported by a pinch roller support shaft in its inner diameter portion, and has a capstan shaft. In a pinch roller that is crimped with a tape sandwiched between the slide bearings, one of the ends of the sliding bearing inner diameter and the sliding surface of the pinch roller spindle is approximately aligned with the widthwise center of the pinch roller. It is what

In order to solve the above problems, the pinch roller of the second invention is a pinch arm that supports a pinch roller support shaft. In the pinch arm, when the pinch arm has a lower end, a slide bearing and a pinch roller support shaft are provided. It is characterized in that the lower end portion of the sliding surface and the upper end portion in the case of holding the upper surface substantially coincide with the center of the pinch roller in the width direction.

In order to solve the above problems, the pinch roller of the third invention is characterized in that the center of the tape width direction and the center of the pinch roller width direction are substantially aligned.

[0011]

According to the present invention, the capstan shaft and the pinch shaft are always in contact with the pinch roller support shaft even if the angle of the pinch roller support shaft is inclined in the direction of the pinch roller support shaft in the Y direction in FIG. Since the contact pressure between the rollers has a symmetrical distribution with respect to the center of the pinch roller in the width direction, stable running can be obtained without changing the tape height in the tape width direction before and after the pinch roller is crimped to the capstan shaft. Since it is not necessary to adjust the inclination of the pinch roller support shaft with high precision, the cost of the bearing can be reduced.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A pinch roller according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a side sectional view of a pinch roller according to an embodiment of the first invention. In FIG.
Reference numeral 1 is a pinch roller support shaft, 2 is a stopper, and 3 is a cylindrical holder, and a cylindrical elastic body 4 made of, for example, rubber is integrally attached to the outer periphery thereof by baking or the like.
The pinch roller is pressure-bonded to the capstan shaft 7 with the tape 8 sandwiched between the pinch rollers, and the resinous plain bearing 6 is press-fitted into the inner circumference of the cylindrical holder 3. The slide bearing 6 is chamfered at both ends of the sliding surface between the slide bearing 6 and the pinch roller support shaft 1.
a is applied and one of the sliding surface ends formed by chamfering 6a is pressed into the pinch roller so as to match the center in the width direction of the pinch roller. Further, the slide bearing 6 provides a constant clearance between the pinch roller support shaft 1 and the stopper 2 through the polyslider 5 in both thrust directions of the slide bearing 6, and the slide bearing 6 is displaced in the thrust direction more than the clearance. Is preventing. Further, the pinch roller support shaft 1 is set in advance at an angle inclined with respect to the capstan support shaft 7.

The operation of the pinch roller configured as described above will be described below with reference to FIG.

C in FIG. 1 represents a sliding position between the slide bearing 6 press-fitted into the cylindrical holder 3 and the pinch roller support shaft 1. From FIG. 1, a perpendicular line drawn from the C portion to the outer peripheral surface of the pinch roller. Is aligned with the center of the pinch roller in the width direction, and even if the pinch roller support shaft 1 is slightly inclined in the A direction, the contact pressure between the pinch roller outer peripheral portion and the capstan shaft 7 is the center of the pinch roller width direction. The distribution is symmetrical with respect to. As a result, the state in which the tape height in the tape width direction changes before and after the pinch roller is pressed against the capstan shaft 1 is improved.

2A and 2B, when the pinch roller support shaft 1 is tilted in the direction of arrow A, the tape height in the tape width direction is measured before and after the pinch roller is pressed against the capstan shaft 7. It is a figure showing the result of having experimented the change of this in a present example and a conventional example. As can be seen from the figure, in this embodiment (a), the rotation angle range R in the A direction in which the height in the tape width direction does not change before and after the pinch roller pressure bonding is improved compared to the conventional example (b).

As described above, according to this embodiment, by making either one of the end portions of the sliding surface between the slide bearing 6 and the pinch roller support shaft 1 coincident with the center of the pinch roller in the width direction, The tape running performance when the pinch roller support shaft 11 is tilted in the direction of arrow A in FIG. 5 can be improved.
Also, due to the improved tape running performance, the pinch roller spindle 1
Since it is not necessary to manage the inclination of 1 with high accuracy, the cost is reduced as a result.

A pinch roller according to an embodiment of the second invention will be described below with reference to the drawings.

FIG. 3 is a side sectional view of a pinch roller according to an embodiment of the second invention. In FIG. 3, 1 is a pinch roller support shaft, 6 is a slide bearing, and 9 is a pinch arm that supports the pinch roller support shaft while holding it down. The other parts are the same as those in the first embodiment of the first invention described above, and the description thereof is omitted here. Further, FIG. 4 is a diagram shown for comparison of the operation with respect to FIG. 3, and is different from FIG. 3 in that the configuration of the pinch arm 9 is held up and supported. 3 and 4, the force exerted from the pinch roller support shaft 1 is set so as to reach the lower end of the sliding surface between the pinch roller support shaft 1 and the slide bearing 6, and the lower end of the sliding surface is set at the lower end of the pinch roller. It matches the center in the width direction.

The operation of the pinch roller configured as described above will be described below with reference to FIGS. 3 and 4.

First, in the case of FIG. 4, when the pinch roller is pressure-bonded to the capstan shaft 7, the pinch roller support shaft 1 receives a predetermined force P for suppressing the inclination. In the case of the above configuration, the pinch roller support shaft 1
In consideration of the force P exerted when the pinch roller is pressure-bonded to the capstan shaft 7, it is necessary to incline a little. This means that it is necessary to increase the clearance between the pinch roller support shaft 1 and the bearing inner diameter portion. Increasing the clearance causes the polyslider 5 to enter between the pinch roller support shaft 1 and the inner diameter portion of the bearing, which causes a hindrance to the centering action of the pinch roller. Further, if the clearance between the inner diameter portion of the slide bearing 6 and the pinch roller support shaft 1 is widened, the true contact area between the slide bearing 6 and the pinch roller support shaft 1 becomes small, and the life performance deteriorates.

On the other hand, in the case of the structure shown in FIG. 3, the force for pressing the pinch roller onto the capstan shaft 7 acts as a force P in the direction of increasing the inclination of the pinch roller support shaft 1. With this configuration,
Since the clearance between the pinch roller support shaft 1 and the inner diameter portion of the slide bearing 6 can be suppressed to a necessary minimum, the poly slider 5
Enters between the pinch roller support shaft 1 and the inner diameter of the bearing,
The possibility of hindering the centering action of the pinch roller is reduced. Further, the reduction of the true contact area between the slide bearing 6 and the pinch roller support shaft 1 is also minimized, and the deterioration of life performance is also minimized.

It should be noted that the pinch arm 9 is supported on the upper side,
The same effect can be obtained by aligning the widthwise center of the pinch roller with the upper end of the sliding bearing sliding surface.

As described above, according to this embodiment, the upper end of the bearing sliding surface between the slide bearing and the pinch roller support shaft is aligned with the center of the pinch roller in the width direction, and the pinch roller support shaft is held up. The clearance between the inner diameter of the slide bearing and the pinch roller support shaft can be supported by supporting it, or by matching the lower end of the bearing sliding surface with the center of the pinch roller width direction and supporting the pinch roller support shaft underneath. The number can be reduced, and the state in which the polyslider enters between the slide bearing inner diameter portion and the pinch roller support shaft and interferes with the centering operation is improved. Further, the reduction of the true contact area between the slide bearing 6 and the pinch roller support shaft 1 is also minimized, and the deterioration of life performance is also minimized.

The pinch roller of the third embodiment of the present invention will be described below. Although the configuration is the same as that of FIG. 1 in one embodiment of the first invention, this embodiment further includes a pinch roller spindle 1 so that the center in the tape width direction and the center in the width direction of the pinch roller coincide with each other. The height of is adjusted.

The operation will be described below. In the above-described embodiment of the first invention, when the contact pressure between the capstan shaft 1 and the pinch roller is unbalanced with respect to the center of the pinch roller in the width direction, when the contact pressure between the capstan shaft 1 and the pinch roller is unbalanced. As described above, the tape height changes in the tape width direction. On the other hand, in the state of the first embodiment of the present invention, when the center in the tape width direction and the center in the width direction of the pinch roller do not match, the contact pressure between the tape and the pinch roller is the center in the tape width direction. Is no longer symmetric to. If the tape 8 is not symmetrical, the tension in the width direction applied to the tape 8 becomes uneven with respect to the center in the tape width direction, which causes damage such as wrinkles on the tape 8. Therefore, to correct this condition,
In this embodiment, the center in the tape width direction and the center in the width direction of the pinch roller are aligned.

As described above, according to the present embodiment, by making the center in the tape width direction and the center in the pinch roller width direction coincide, the tension distribution in the tape width direction becomes uniform with respect to the center in the tape width direction. , The condition that the tape is easily damaged such as wrinkles is improved.

[0028]

As described above, in the pinch roller of the first aspect of the invention, one of the sliding surface end portions of the slide bearing inner diameter portion with the pinch roller support shaft is approximately centered in the width direction of the pinch roller. By making them coincide with each other, the tape running stability can be maintained even if the pinch roller support shaft is tilted in the direction A in FIG.
There is no need for excessive adjustment in the direction, resulting in cost reduction.

In the pinch roller of the second invention, the lower end portion of the sliding surface between the slide bearing and the pinch roller support shaft is used when the pinch arm is held downward, and the upper end portion is used when the pinch arm is held upward. By aligning with the center of the direction approximately, the clearance between the inner diameter of the slide bearing and the pinch roller support shaft can be minimized, and the polyslider enters between the stopper and the pinch roller support shaft. The state in which the centering of the roller is disturbed is improved, and the centering action is performed more reliably.

Further, the pinch roller of the third invention is the first invention.
Alternatively, in the pinch roller of the second invention, the tension distribution in the tape width direction is made uniform with respect to the center in the tape width direction by making the center in the tape width direction substantially coincide with the center in the width direction of the pinch roller. Therefore, the state where the tape is easily damaged such as wrinkles is improved.

[Brief description of drawings]

FIG. 1 is a side sectional view of a pinch roller according to an embodiment of the first invention.

FIG. 2 is a diagram showing a change in tape height in a tape width direction around a capstan axis in an embodiment of the first invention and a conventional example.

FIG. 3 is a side sectional view of a pinch roller according to an embodiment of the second invention.

FIG. 4 is a side sectional view showing a comparison with a pinch roller in one embodiment of the second invention.

FIG. 5 is a side sectional view of a pinch roller in a conventional example.

[Explanation of symbols]

 1 Pinch roller support shaft 2 Stopper 3 Cylindrical holder 4 Cylindrical elastic body 5 Poly slider 6 Sliding bearing 6a Sliding bearing chamfer 7 Capstan shaft 8 Tape 9 Pinch arm 11 Pinch roller support shaft 12 Stopper 13 Cylindrical holder 14 Cylindrical Elastic body 15 Polyslider 16 Sliding bearing 16a Sliding bearing chamfer 17 Capstan shaft 18 Tape

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeki Murata 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (3)

[Claims] 1. A pinch roller having a slide bearing rotatably supported by a pinch roller support shaft in an inner diameter portion and crimped with a tape on a capstan shaft, wherein the pinch of the inner diameter portion of the slide bearing is provided. A pinch roller characterized in that either one of the ends of the sliding surface with respect to the roller support shaft is substantially aligned with the widthwise center of the pinch roller. 2. A pinch arm for supporting a pinch roller support shaft, wherein a lower end portion of a sliding surface of the slide bearing and the pinch roller support shaft is provided when the pinch arm is held downward, and an upper end portion when provided with an upper support. The pinch roller according to claim 1, wherein the pinch roller is substantially aligned with the center of the pinch roller in the width direction. 3. The pinch roller according to claim 1, wherein the center in the tape width direction and the center in the width direction of the pinch roller are substantially aligned with each other.