JP3168816B2 - Pinch roller - Google Patents

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, with the aim of stabilizing the tape speed by increasing the precision of magnetic recording / reproducing apparatuses, the importance of increasing the precision of pinch rollers has become more and more important, and inexpensive pinch rollers have been provided. Above, the cost reduction of the pinch roller cannot be avoided. In order to reduce the cost of the pinch roller, various shapes have conventionally been studied. Among them, as the bearings used for the pinch rollers, widely used are ball bearings which have been conventionally used, and resin sliding bearings having a simple structure and a low cost are used.

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

The operation of the conventional pinch roller configured as described 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 across the tape 18, the tape 18 is transferred to the capstan shaft 17 for some reason. Even when the pinch roller support shaft 11 is in a non-parallel state, the pinch roller presses along the inclination of the capstan by the self-aligning action, so that the tape transfer can be realized. Also, by using a resin sliding bearing instead of a ball bearing for the bearing,
The cost can be reduced as compared with conventionally used ball bearings.

[0005]

However, the conventional pinch roller having the above configuration has the following problems.

In the pinch roller having the above-described configuration, as compared with a conventional pinch roller using a ball bearing as a bearing, the pinch roller support shaft 11 is connected to the capstan shaft 17 in a direction about the X direction in FIG. When the pinch roller is inclined, contact between the pinch roller support shaft 11 and the slide bearing 16 always occurs at the center of the slide bearing. Therefore, the contact pressure between the capstan shaft 17 and the pinch roller always has a symmetric distribution with respect to the center in the width direction of the pinch roller. On the other hand, when the pinch roller support shaft 11 is inclined in a direction with the rotation direction being the Y direction 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 symmetric distribution with respect to the center in the width direction of the pinch roller. However, when the pinch roller support shaft 11 is slightly inclined with respect to the capstan shaft 17, the contact between the pinch roller support shaft 11 and the slide bearing 16 becomes the upper end or the lower end 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 in the width direction of the pinch roller, and the tape height in the tape width direction around the capstan shaft 17 is reduced by the pinch roller pressure bonding. This may cause a change before and after. For this reason, the inclination accuracy of the pinch roller support shaft 11 must be controlled with high precision so as not to incline in the direction A in FIG. 1, and as a result, the cost is lower than when a pinch roller using a ball bearing is used as a bearing. There was a problem of inviting up.

[0007] In view of the above problems, an object of the present invention is to provide a pinch roller for improving the running stability of a tape by using the bearing according to the present invention for a pinch roller bearing.

[0008]

According to a first aspect of the present invention, there is provided a pinch roller having a slide bearing rotatably supported by a pinch roller support shaft on an inner diameter portion, and a capstan shaft. In a pinch roller that is pressure-bonded with a tape in between, one of the sliding surface end portions of the inner diameter of the slide bearing and the pinch roller support shaft substantially coincides with the center in the width direction of the pinch roller. It is assumed that.

According to a second aspect of the present invention, there is provided a pinch roller for supporting a pinch roller support shaft, wherein, when the pinch arm has a lower end, a slide bearing and a pinch roller support shaft are provided. The sliding surface is characterized in that the lower end is substantially aligned with the center of the pinch roller in the width direction when the sliding surface is held up.

In order to solve the above problem, a pinch roller according to a third aspect of the present invention is characterized in that the center in the width direction of the tape substantially coincides with the center in the width direction of the pinch roller.

[0011]

According to the present invention, the pinch roller support shaft is always in contact with the capstan shaft even when the angle of the pinch roller support shaft is tilted in the direction of 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, a stable running in which the tape height in the tape width direction does not change before and after the pinch roller is pressed against the capstan shaft can be obtained. Therefore, it is not necessary to adjust the inclination of the pinch roller support shaft with high precision, and as a result, the cost of the bearing can be reduced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a pinch roller according to an embodiment of the present invention will be described 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.
1 is a pinch roller support shaft, 2 is a stopper, 3 is a cylindrical holder, and a cylindrical elastic body 4 made of rubber, for example, is integrally attached to its outer periphery by baking or the like.
The pinch roller is pressed against a capstan shaft 7 with a tape 8 interposed therebetween, and a resin-made sliding bearing 6 is press-fitted on the inner periphery of the cylindrical holder 3. The sliding bearing 6 has chamfers 6 on both sides of the sliding surface between the pinch roller support shaft 1 and the sliding bearing.
a, and one of the sliding surface ends formed by chamfering 6a is press-fitted so as to coincide with the center of the pinch roller in the width direction. Further, the slide bearing 6 provides a fixed gap between the pinch roller support shaft 1 and the stopper 2 via the poly slider 5 in both thrust directions of the slide bearing 6, and the slide bearing 6 is shifted in the thrust direction more than the gap. Is preventing. In addition, the pinch roller support shaft 1 is set in advance at an angle to the capstan support shaft 7.

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

In FIG. 1, C represents a sliding portion between the slide bearing 6 press-fitted into the cylindrical holder 3 and the pinch roller support shaft 1. FIG. 1 shows a perpendicular line lowered from the portion C to the outer peripheral surface of the pinch roller. Are 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 direction A, the contact pressure between the outer peripheral portion of the pinch roller and the capstan shaft 7 is the center of the pinch roller in the width direction. 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.

2 (a) and 2 (b) show the tape height in the tape width direction before and after the pinch roller is pressed against the capstan shaft 7 when the pinch roller support shaft 1 is tilted in the direction of arrow A. FIG. 7 is a diagram showing the results of experiments on the change in the present embodiment and the conventional example. As can be seen from the drawing, the rotation angle range R in the direction A in which the height in the tape width direction does not change before and after the pinch roller compression is improved in the present embodiment (a) as compared with the conventional example (b).

As described above, according to this embodiment, one of the ends of the sliding surface between the slide bearing 6 and the pinch roller support shaft 1 is made to coincide with the center of the pinch roller in the width direction. The tape running performance when the pinch roller support shaft 11 is inclined in the direction of arrow A in FIG. 5 can be improved.
In addition, the pinch roller support shaft 1 is improved by improving the tape running performance.
Since it is not necessary to manage the inclination of 1 with high precision, the cost is reduced as a result.

Hereinafter, a pinch roller according to an embodiment of the second invention will be described with reference to the drawings.

FIG. 3 is a sectional side 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 with a lower end. The other parts are the same as those in the embodiment of the first invention already described, and the description thereof is omitted here. FIG. 4 is a diagram for comparison of the operation with FIG. 3, and is different from FIG. 3 in that the configuration of the pinch arm 9 is supported by upright support. 3 and 4, the force applied 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 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.

First, in the case of FIG. 4, when the pinch roller is pressed against the capstan shaft 7, a force P is applied to the pinch roller support shaft 1 so as to suppress the inclination given in advance. In the case of the above configuration, the pinch roller support shaft 1
In view of the force P applied when the pinch roller is pressed against the capstan shaft 7, it is necessary to tilt the pinch roller a little. This means that it is necessary to increase the clearance between the pinch roller support shaft 1 and the inner diameter of the bearing. Increasing the clearance causes the polyslider 5 to enter between the pinch roller support shaft 1 and the inner diameter of the bearing, which hinders the centering action of the pinch roller. If the clearance between the inner diameter of the slide bearing 6 and the pinch roller support shaft 1 is increased, the true contact area between the slide bearing 6 and the pinch roller support shaft 1 is reduced, and the life performance is deteriorated.

On the other hand, in the configuration shown in FIG. 3, the force for pressing the pinch roller against the capstan shaft 7 acts as a force P in the direction to increase the inclination of the pinch roller support shaft 1. In this configuration,
Since the clearance between the pinch roller support shaft 1 and the inner diameter of the slide bearing 6 is minimized, 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. Also, the reduction of the true contact area between the slide bearing 6 and the pinch roller support shaft 1 is minimized, and the deterioration of the life performance is also minimized.

It should be noted that the pinch arm 9 is supported upright,
The same effect can be obtained even if the center of the sliding bearing sliding surface upper end portion in the width direction of the pinch roller is made to coincide.

As described above, according to this embodiment, the upper end portion of the bearing sliding surface between the slide bearing and the pinch roller support shaft coincides 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 increased by supporting or aligning the lower end of the bearing sliding surface with the center of the pinch roller in the width direction, and supporting the pinch roller support shaft with a lower support. It is possible to improve the condition that the polyslider enters between the slide bearing inner diameter portion and the pinch roller support shaft and hinders the alignment operation. Also, the reduction of the true contact area between the slide bearing 6 and the pinch roller support shaft 1 is minimized, and the deterioration of the life performance is also minimized.

Hereinafter, a pinch roller according to an embodiment of the third invention will be described. Although the configuration is the same as that of the first embodiment of FIG. 1, the present embodiment further includes a pinch roller support shaft 1 such that the center in the tape width direction coincides with the center in the width direction of the pinch roller. The height of is adjusted.

Hereinafter, the operation will be described. In the above-described embodiment of the first invention, when the contact pressure between the capstan shaft 1 and the pinch roller becomes unbalanced with respect to the center in the width direction of the pinch roller in the contact between the capstan shaft 1 and the pinch roller. As described above, the tape height in the tape width direction changes. On the other hand, in the state of the embodiment of the first invention, when the center in the tape width direction does not coincide with the center in the width direction of the pinch roller, the contact pressure between the tape and the pinch roller becomes the center in the tape width direction. Is no longer symmetric with respect to If the tape 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 width direction of the tape and the center in the width direction of the pinch roller coincide with each other.

As described above, according to this embodiment, the tension distribution in the tape width direction becomes uniform with respect to the center in the tape width direction by matching the center in the tape width direction with the center in the pinch roller width direction. Thus, the state in which the tape is easily damaged by wrinkles and the like is improved.

[0028]

As described above, in the pinch roller according to the first aspect of the present invention, one of the sliding surface inner ends of the sliding bearing and the sliding surface end with the pinch roller support shaft is substantially 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 inclined in the direction A in FIG.
It is not necessary to adjust the direction excessively, resulting in cost reduction.

In the pinch roller according to the second invention, the lower end of the sliding surface between the slide bearing and the pinch roller support shaft is provided when the pinch arm is held down, and the upper end is provided when the pinch arm is held up. By making them approximately coincide with the center of the direction, the clearance between the slide bearing inner diameter part and the pinch roller support shaft can be minimized, and the poly slider enters between the stopper and the pinch roller support shaft, and the pinch The state in which the centering of the rollers is hindered is improved, and the centering action is performed more reliably.

Further, the pinch roller according to the third aspect of the present invention is characterized in that
Alternatively, in the pinch roller according to the second aspect of the present invention, the center in the tape width direction and the center in the width direction of the pinch roller substantially coincide with each other so that the tension distribution in the tape width direction is equal to the center in the tape width direction. Thus, the state in which the tape is easily damaged by wrinkles and the like is improved.

[Brief description of the 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 in one 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]

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

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Shigeki Murata 1006 Kazuma Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-2-123546 (JP, A) 31433 (JP, U) JP-A-3-37631 (JP, U) JP-A-4-12130 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 15/29

Claims (3)

(57) [Claims] 1. A pinch roller having a slide bearing rotatably supported by a pinch roller support shaft on an inner diameter portion and pressing a tape on a capstan shaft, wherein the pinch of the slide bearing inner diameter portion is provided. A pinch roller characterized in that one of a sliding surface end and a roller support shaft substantially coincides with the center in the width direction of the pinch roller. 2. A pinch arm supporting a pinch roller support shaft, wherein the lower end of the sliding surface between the slide bearing and the pinch roller support shaft is provided when the pinch arm is held down, and the upper end is provided when the pinch arm is held up. 2. The pinch roller according to claim 1, wherein the distance is substantially coincident with the center of the pinch roller in the width direction. 3. The pinch roller according to claim 1, wherein the center in the width direction of the tape substantially coincides with the center in the width direction of the pinch roller.