JPH0636246A - Rotary body drive device - Google Patents

Abstract

PURPOSE:To prevent a belt from falling off even if the opening direction of a groove of a follower pulley is inclined to the direction of the rotary surface of the follower pulley. CONSTITUTION:Formation surfaces 41a and 41b of a groove 41 of a follower pulley 4 at the delivery part of a belt 5 in a follower pulley 4, namely at an extended side 41d of the belt 5, are asymmetrical for a rotary surface 8 passing through a deepest part 41 of the groove 41. When a drive motor 1 is rotated, the belt 5 is pulled by the delivery part 41d of the groove 41 and then goes out while rotating a drum 3 via a drive pulley 2 and inclines an opening direction D of the groove 41 toward a horizontal surface 9 for agreeing with the direction of the rotary surface of the drive pulley 2 or for bringing closer to it. Also, the formation angle of the groove 4 for the horizontal surface is made equal for both the drive pulley 2 and the follower pulley 4, thus equalizing the force in thrust direction exerted on the belt 5 and hence preventing the belt 5 from falling off.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to, for example, DAT (digital audio tape recorder), VTR (video recorder).
The present invention relates to a rotary body driving device that can be suitably used for a magnetic recording / reproducing device having a helical scan type belt drive type rotary drum such as a tape recorder).

[0002]

2. Description of the Related Art FIG. 5 shows a D using a conventional rotary body driving device.
FIG. 6 is a plan view showing an AT tape path system, and FIG.
6 is a side view in the direction of line VI (view from the arrow), and FIG. 7 is a side view in the direction of line VII-VII in FIG. 6 (view from the arrow). In the figure, 1 is a drive motor, 2 is a drive pulley which is rotated by the drive motor 1 in the direction of arrow A, 3 is a rotary drum as a rotating body, 4 is a driven pulley which rotationally drives the rotary drum 3, and 41 is this driven drum. Guide grooves 5 provided on the pulley 4 indicate belts mounted on the drive pulley 2 and the driven pulley 4. Reference numeral 6 shown by a chain line in FIG. 5 records an information signal.
It is a magnetic tape for reproduction. 6 and 7
Reference numeral 7 indicated by an alternate long and short dash line therein is a rotation center axis of the rotating body 3, and the center axis 7 is provided so as to be inclined by an angle θ with respect to the Z axis parallel to the axis of the drive motor 1.

Next, the operation will be described. When the drive pulley 1 is rotated by the drive motor 1 in the direction of arrow A, the driven pulley 4 is rotated in the direction of arrow B via the belt 5, and the rotary drum 3 is rotated by the rotary shaft 3a as shown by arrow B in FIG. It is driven to rotate counterclockwise. At this time, the magnetic tape 6 running by the drive device (not shown) is rotated by the rotary drum 3.
5, a signal is recorded on the magnetic tape 6 by a recording / reproducing head (not shown) provided on the rotating drum 3 and tilted with respect to the rotating drum 3 as shown in FIG. The signal recorded on the tape 6 is read by the recording / reproducing head.

As described above, in the case of the belt drive system in which the rotary drum 3 is rotated counterclockwise as shown in FIG. 5, the position at which the belt 5 is stretched by the rotation of the drive pulley 2 is at the belt outlet of the driven pulley 4. Side, ie 5a in FIG.
Be on the side. Here, as shown in FIG. 7, the rotation center axis 7 of the rotary drum 3 is inclined by θ with respect to the Z axis parallel to the rotation axis of the drive motor 1. When the direction D of the center line of the angle formed by the V-shaped groove 41 forming surface 41a and 41b is the opening direction of the groove 4, the opening direction D is the deepest part 41 of the groove 41.
Since it is provided so as to coincide with the direction 8 of the rotation surface of c, the plane 8 passing through the center of the feeding portion 41d of the belt 5 and the horizontal plane 9 in the guide groove 41 of the driven pulley 4 are inclined by θ, and therefore The groove forming surfaces 41a, 4a on the right side in FIG. 7, which is the belt feeding side of the pulley 4, that is, the belt tension side.
The angles formed by 1b and the horizontal plane 9 are 45 ° + θ and 45, respectively.
It becomes ° -θ.

Therefore, when the belt 5 is stretched via the drive pulley 2 by the rotational force of the drive motor 1, the groove forming surface 4
The restriction forces in the thrust direction of the belt 5 by 1a and 41b become uneven, and the belt 5 easily moves to the side where the angle between the horizontal surface 9 and the surface where the groove 4 is formed is large, that is, 41a side.

On the other hand, FIGS. 8 and 9 show, for example, an actual flat plane 2-8.
It is an explanatory view showing the important section of the rotary drum drive shown in 4111 gazette, and each numerals show the same portion as the above-mentioned conventional device. In such a conventional device, the belt 5 is crossed between the driving pulley 2 and the driven pulley 4, so that the transmission rate of the driving force is improved.

[0007]

As described above, in the conventional device, the belt 5 moves in the thrust direction, and the driven pulley 4 is moved.
There is a problem that it is easy to drop from the guide groove 41 in the direction of arrow C in FIG. Further, in the conventional apparatus shown in FIGS. 8 and 9, the belt 5 is crossed once, which increases the wrapping angle, which is advantageous for preventing falling, but the work of reversing the belt 5 once when mounting the belt 5 is required. It was necessary, and there was a problem that the workability of deck assembly was deteriorated.

It is an object of the present invention to provide a rotating body drive device which has a simple structure and prevents the belt from falling off without deteriorating the assembly workability of the device.

[0009]

According to the present invention, in the rotary body driving device, the opening direction of the groove of the driven pulley is formed so as to be inclined with respect to the direction of the rotational surface of the driven pulley at the feeding portion of the belt. It is configured in.

[0010]

In the driven pulley according to the present invention, the guide groove is formed such that the opening direction of the guide groove is inclined with respect to the direction of the rotational surface of the driven pulley in the feeding portion of the belt. Force is applied in the direction of inclination to prevent the belt from falling out of the groove.

[0011]

【Example】

Example 1. FIG. 1 is a side view showing a main part of a rotary body driving apparatus according to an embodiment of the present invention, and FIG. 2 is a side view showing a belt mounted state of the embodiment of FIG. In the figure, the reference numerals indicate the same or corresponding parts as those of the above-mentioned conventional device, and therefore the description thereof is omitted. In this embodiment, the feeding portion of the belt 5 in the driven pulley 4, that is, the tension side 4 of the belt 5.
1d, the surfaces 41a and 4 where the grooves 41 of the driven pulley 4 are formed.
1b is asymmetric with respect to the rotation surface 8 passing through the deepest portion 41c of the groove 4. That is, the opening direction of the groove 41, that is,
The direction D of the center line of the angle formed by the grooves 4 forming surfaces 41a and 41b is inclined with respect to the rotating surface 8 by an angle γ.

For example, when the angle formed by the surfaces 41a and 41b is 90 °, the forming surface 41 of the V-shaped groove 4 on the upper side in the drawing is formed.
The angle α formed by a and the horizontal plane 9 is set to 0 ° or more and less than 45 °, and the angle β formed by the lower surface 41b and the horizontal plane 9 is set to 90 ° -α.

Next, the operation will be described. Drive motor 1
When the belt is rotated, the belt 5 is pulled out of the feeding portion 41d of the groove 41 through the driving pulley 2 while rotating the driven pulley 4 and the rotating drum 3 by the rotation torque of the driving motor 1. The opening direction D of the groove 41 in the portion 41d is inclined in the direction of the horizontal plane 9 so as to match or approach the direction of the rotation surface of the drive pulley 2, that is, the formation angle of the groove 4 with respect to the horizontal plane is driven by the drive pulley 2 and the driven pulley 2. Since the pulley 5 and the pulley 4 are made equal to each other, the forces acting on the belt 5 in the thrust direction are equalized, and the belt 5 can be prevented from falling off. Further, since the belt 5 does not need to be inverted, the device can be easily assembled.

Since the rotary drum 3 used in the magnetic recording / reproducing apparatus is designed to rotate only in one direction, the driving motor 1 always rotates in only one direction, and the belt 5 is stretched in one direction. Only correspondence is enough. Also,
The opening direction D does not necessarily have to coincide with the direction of the horizontal plane 9.

Example 2. FIG. 3 is a side view showing an essential part of another embodiment of the present invention. In the figure, each reference numeral indicates the same or corresponding portion as that of the embodiment shown in FIG.
In this embodiment, the forming surface 41 of the groove 41 on the upper side of the drawing is shown.
The angle formed by a and the horizontal surface 9 and the forming surface 4 on the lower side of the drawing
1b and the horizontal surface 9 form an angle equal to each other. In this embodiment, the inclination angle of the rotary drum 3 with respect to the Z axis is θ, the angle formed by the forming surfaces 41a and 41b is 90 °, and the angle α formed by the surface 41a and the flat surface 8 is as shown in FIG. 45 ° −θ, the angle β formed by the forming surface 41b and the plane 8 is 45 ° + θ, and the opening direction D of the groove 41 is relative to the direction 8 of the rotation surface of the driven pulley 4 as shown in the figure. It is formed so as to be inclined by θ and equal to the horizontal plane 9.

Next, the operation will be described. According to this embodiment, the angle formed by the horizontal surface 9 and the forming surface 41a and the angle formed by the horizontal surface 9 and the surface 41b are both 45 °, and the forces acting on the belt 5 in the thrust direction are equalized.
The effect of preventing the belt from falling off along the surface 41a is increased.

As another embodiment of these embodiments, the opening direction of the groove 41 of the drive pulley 2 may be inclined to obtain the same effect. That is, the formation angle of the groove 41 may be asymmetrical. Furthermore, the surface 4 on which the groove 41 is formed
The angle formed by 1a and 41b is not limited to 90 °. Further, the opening direction D of the groove 41 does not necessarily have to be completely aligned with the direction of the horizontal plane 9.

Example 3. FIG. 4 is a side view showing a main part of still another embodiment of the present invention. In the figure, 5 is a square belt having a substantially square cross section. Other reference numerals indicate the same or corresponding portions as those shown in FIG.

Next, the operation will be described. The area of the contact portion between the belt 5 and the one V-shaped groove forming surface 41a of the driven pulley 4 and the area of the contact portion between the other one surface 41b are the same because the belt 5 has a square cross-sectional shape. Therefore, the frictional force between the belt 5 and the driven pulley 4 on the side 41a and the side of the driven pulley 4 are equalized, and the effect of preventing the belt from falling is increased.

By the way, the above-mentioned embodiment is merely an example shown for facilitating the understanding of the present invention, and in addition to the above, various modifications and changes can be made within the spirit of the present invention. is there. For example, the present invention is applicable to other A than DAT.
Similar effects can be expected when applied to V equipment and other devices. Needless to say, the rotating body 3 is not limited to the rotating drum, and for example, the driven pulley itself,
Alternatively, the driven pulley 4 and the rotating body 3 may be integrally formed. Further, although the groove 41 has a V-shaped cross section, the groove 41 is not limited to this and may have, for example, a U shape, a semicircular shape, an oval shape, or any other shape. The cross-sectional shape of the belt 5 is not limited to that of the embodiment, and may be circular in cross section, suigy circular, or any other shape.

[0021]

As described above, according to the present invention, the opening direction of the groove of the driven pulley is set at the feeding portion of the belt.
Since the driven pulley is formed so as to be inclined with respect to the direction of the rotation surface, it is possible to prevent the belt from falling off with a simple structure without deteriorating the assembly workability of the device.

[Brief description of drawings]

FIG. 1 is a side view showing a main part of a rotary body driving device according to an embodiment of the present invention.

FIG. 2 is a side view showing a belt mounted state in the embodiment shown in FIG.

FIG. 3 is a side view showing a main part of a rotary body driving device according to another embodiment of the present invention.

FIG. 4 is a side view showing a main part of still another embodiment of the present invention.

FIG. 5 is a plan view showing a DAT tape path system as a conventional device.

FIG. 6 is a side view showing a mounted state of a belt of the conventional device of FIG.

FIG. 7 is a side view showing a main part of a conventional device.

FIG. 8 is a perspective view showing another example of a conventional device.

9 is a perspective view showing a tape path system of the conventional apparatus shown in FIG.

[Explanation of symbols]

 2 Drive pulley 3 Rotating body (rotary drum) 4 Driven pulley 5 Belt 41 Groove 41d Feeding part D Opening direction

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] September 16, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

Next, the operation will be described. When the drive pulley 1 is rotated by the drive motor 1 in the direction of arrow A, the driven pulley 4 is rotated in the direction of arrow B via the belt 5, and the rotary drum 3 is rotated by the rotary shaft 3a as shown by arrow B in FIG.
Is rotated counterclockwise. At this time, the magnetic tape 6 running by the drive device (not shown) is rotated by the rotary drum 3.
5, a signal is recorded on the magnetic tape 6 by a recording / reproducing head (not shown) provided on the rotating drum 3 and tilted with respect to the rotating drum 3 as shown in FIG. The signal recorded on the tape 6 is read by the recording / reproducing head.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction content]

[0011]

EXAMPLES Example 1. FIG. 1 is a side view showing a main part of a rotary body driving apparatus according to an embodiment of the present invention, and FIG. 2 is a side view showing a belt mounted state of the embodiment of FIG. In the figure, the reference numerals indicate the same or corresponding parts as those of the above-mentioned conventional device, and therefore the description thereof is omitted. In this embodiment, the feeding portion of the belt 5 in the driven pulley 4, that is, the tension side 4 of the belt 5.
1d, the surfaces 41a and 4 where the grooves 41 of the driven pulley 4 are formed.
1b is asymmetric with respect to the rotation surface 8 passing through the deepest portion 41c of the groove 4. That is, the opening direction of the groove 41, that is,
The direction D of the center line of the angle formed by the formation surfaces 41 a and 41 b of the groove 41 is inclined by an angle γ with respect to the rotation surface 8.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

For example, when the angle formed by the surfaces 41a and 41b is 90 °, the forming surface 4 of the V-shaped groove 41 on the upper side in the drawing is formed.
The angle α formed by 1a and the horizontal plane 9 is 0 ° or more and less than 45 °, and the angle β formed by the lower surface 41b and the horizontal plane 9
To 90 ° -α.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

Next, the operation will be described. Drive motor 1
When the belt is rotated, the belt 5 is pulled out of the feeding portion 41d of the groove 41 through the driving pulley 2 while rotating the driven pulley 4 and the rotating drum 3 by the rotation torque of the driving motor 1. The opening direction D of the groove 41 in the portion 41d is inclined in the direction of the horizontal plane 9 so as to coincide with or approach the direction of the rotation surface of the drive pulley 2, that is, the formation angle of the groove 41 with respect to the horizontal plane is driven by the drive pulley 2 and the driven pulley 2. Belt 5 is the same as pulley 4
The force acting in the thrust direction becomes even, and the belt 5 can be prevented from falling off. Further, since the belt 5 does not need to be inverted, the device can be easily assembled.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction content]

As another embodiment of these embodiments, the opening direction of the groove 41 of the drive pulley 2 may be inclined to obtain the same effect. That is, the formation angle of the groove 41 may be asymmetrical. Furthermore, the surface 4 on which the groove 41 is formed
The angle formed by 1a and 41b is not limited to 90 °. Further, the opening direction D of the groove 41 does not necessarily have to be completely aligned with the direction of the horizontal plane 9.

[Procedure correction 6]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 5

[Correction method] Change

[Correction content]

[Figure 5]

Claims (1)

[Claims] 1. A drive pulley having a guide groove, a rotary body having a rotary shaft inclined at a predetermined angle with respect to the rotary shaft of the drive pulley, and a driven body having a guide groove for rotationally driving the rotary body. In a rotary body driving device including a pulley and a belt mounted on these pulleys, an opening direction of a groove of the driven pulley is inclined with respect to a direction of a rotation surface of the driven pulley at a feeding portion of the belt. A rotating body drive device characterized by being formed as follows.