JPH06282901A - Capstan device - Google Patents

Abstract

PURPOSE:To unnecessitate a clutch at the reel base side by incorporating the clutch at the capstan side and to attain the cost reduction in accordance with the cutdown of assembling man-hour due to the reduction of the number of components and the tolerance relaxation of the reel base due to the reduction of components constituting the reel base. CONSTITUTION:Clutch disks A and B are fixed on a capstan shaft 1. Magnets Am and Bm for attraction are respectively arranged on the outer peripheries of the clutch disks A and B. A clutch felt Af is arranged on the surface of clutch disk A opposite to a rotor yoke 3. A clutch felt Bf is arranged on the surface of clutch disk B opposite to the clutch disk A. A clutch effect is brought by the friction between the clutch felts Af and Bf.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capstan for a magnetic recording / reproducing device such as a VTR.

[0002]

2. Description of the Related Art Conventionally, a capstan device for feeding a magnetic tape together with a pinch roller has a structure as shown in FIG. One end 61a of the capstan shaft 61 is fixed to a rotor yoke 63 by a bush 62, and a plurality of rotor magnets 65 that operate by the magnetism of a plurality of starter coils 64 are arranged on the rotor yoke 63. The starter coil 64 is fixed to a mounting plate 66 that is fixed to the main body of the VTR so as to face the rotor magnet 65. A current is sequentially applied to the plurality of starter coils 64 to generate magnetism and repel each other with the rotor magnet 65, thereby generating a rotational force on the capstan shaft 61.

The bushing 62 side of the capstan shaft 61 is a bearing bearing 67, and the other end 61b is a bearing 68.
It is rotatably supported by. The bearing 68 is arranged in a housing 69 fixed to a mounting plate.

A pulley 610 inserted and attached to the end 61a side of the capstan shaft 61 transmits power to a reel stand by a rubber belt 611 or the like. The power transmitted from the capstan shaft 61 via the rubber belt 611 or the like is supplied to each reel base on the supply side and the winding side by the drive switching unit having the swing mechanism shown in FIG. 7 (FIG. 7 shows one reel). Showing the stand). The power from the capstan shaft 61 is transmitted to the reel gear 71. Next, the clutch felt 72 crimped to the reel gear 71 transmits power to the reel boss 73.

The power transmitted to the reel boss 73 is transmitted to the reel stand 75 by a clutch spring 74 arranged so as to pass through the central axis of the reel boss 73. The clutch spring 73 keeps the rotational torque constant.
Further, the power transmitted to the reel base 75 is transmitted to the reel top 77 by the reel top spring 76 and drives the reel of the cassette.

However, in the above-mentioned conventional capstan device, in order to stably perform the operations of reproduction, fast-forwarding and rewinding, the supply side and take-up side reel stands must be equipped with separate clutches. However, there is a problem that the number of components increases. In addition, the difficulty of assembly accuracy has increased, which has led to an increase in cost.

[0007]

As described above, according to the conventional capstan device, it is necessary to separately incorporate clutches in the reel bases on the supply side and the winding side, which increases the number of components. was there.

In view of the above, the present invention eliminates the above-mentioned drawbacks, and by incorporating a clutch on the capstan side, the clutch on the reel stand side is not required, and the number of parts is reduced to reduce the number of assembly steps and the number of reel stand components. It is an object of the present invention to provide a capstan device that can reduce the cost due to the relaxation of the tolerance of the reel stand.

[0009]

In order to achieve the above object, according to the present invention, a capstan shaft disposed as a rotary shaft of a direct drive motor, a rotor yoke coaxially fixed to the capstan shaft, and A rotor magnet fixed to the rotor yoke; a suction magnet facing the rotor magnet and having a rotation center coaxial with the capstan shaft; and a rotation center coaxial with the capstan shaft. And a clutch member having a clutch effect, which is disposed between the suction magnet and the suction magnet.

[0010]

In the structure thus constructed, the capstan motor, which is the drive source of the reel base, uses the capstan motor with the multiple clutch, thereby reducing the number of assembly steps by reducing the number of parts of the reel base and the reel base constituent parts. It is possible to reduce the cost by reducing the tolerance of the reel stand by reducing

[0011]

Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a capstan device according to an embodiment of the present invention. The capstan shaft 1 is fixed to a rotor yoke 3 via a bush 2 on one end 1a side, and a rotor magnet 5 is arranged on the rotor yoke 3. Starter coil 4 facing the rotor magnet 5
Is fixed to the mounting plate 6 fixed to the VTR main body.
By supplying an electric current to the starter coil 4 to generate magnetism and repel each other with the rotor magnet 5, a rotational force is generated on the capstan shaft 1.

A bearing bearing 7 rotatably supports the capstan shaft 1 near the bush 2 and a bearing 8 rotatably supports the end 1b of the capstan shaft 1. The bearing 8 and the bearing bearing are arranged in a housing 9 fixed to the mounting plate 6. Further, a slip-out preventing bush 10 is attached to the end of the bush 2 side.

Further, from the rotor yoke 3 attached to the bush 2 on the most end side, the clutch disks A and B are
Is fixed to the capstan shaft 1. Suction magnets Am and Bm are arranged on the outer circumferences of the clutch disks A and B, respectively.

A clutch felt Af is arranged on the surface of the clutch disk A facing the rotor yoke 3. Further, a clutch felt Bf is arranged on the surface of the clutch disc B facing the clutch disc A.

Rotor magnet 5, attracting magnet A
The outer peripheral portions of B and B are gears and supply power to the reel side. The clutch disc A is attracted to the rotor yoke 3 by the rotor magnet 5 having a larger diameter than the rotor yoke 3 and the attraction magnet Am attached to the clutch disc A. Since the clutch felt Af is disposed on the clutch disc A, friction is transmitted with the rotation of the rotor yoke 3 and the clutch disc A rotates with a constant torque.

Since the clutch disc B is attracted to the clutch disc A by the attraction magnet Bm, the clutch disc B rotates with a constant torque due to the friction transmission of the clutch felt Bf attached to the clutch disc B.

The relationship between the transmission torques of the rotor yoke 3, the clutch disc A and the clutch disc B is rotor yoke 3> clutch disc A> clutch disc B.
FIG. 2 is a configuration diagram showing a supply and take-up reel when this embodiment is used. The power transmitted from the capstan shaft 1 via a pulley or the like is supplied to each reel stand on the supply side and the winding side by a drive switching unit having a swing mechanism. The power from the capstan shaft 1 is transmitted to a gear provided on the outer circumference of the reel stand 11. The power transmitted to the reel base 11 rotates the reel base 11 in a predetermined direction. The power of the reel stand 11 is transmitted to the reel top 13 by the reel top spring 12 arranged so as to pass through the central axis of the reel, and drives the reels of the cassette.

FIGS. 3, 4 and 5 are explanatory views showing the operating principle of the capstan device in this embodiment. 3 shows the reproduction mode, FIG. 4 shows the reverse reproduction mode, and FIG. 5 shows the fast-forward and rewind modes.

The relationship of the torque required in each mode is fast forward and rewind> reverse reproduction> reproduction. In the reproduction mode, as shown in FIG. 3, power is transmitted from the clutch disc Bm to the pulley gear 15 via the idler gear 14. The power transmitted to the pulley gear 15 is supplied from the pulley 16 coaxially fixed to the pulley gear 15 to the reel stand on the winding side by a drive switching unit having a swing mechanism.

In the reverse regeneration mode, as shown in FIG. 4, power is transmitted from the clutch disk Am to the pulley gear 15 via the idler gear 14. The power transmitted to the pulley gear 15 is supplied from the pulley 16 coaxially fixed to the pulley gear 15 to the reel base on the supply side by a start switching unit having a swing mechanism.

Since the most torque is required in the fast-forward and rewind modes, as shown in FIG. 5, power is transmitted from the rotor magnet 5 to the pulley gear 15 via the idler gear 14 without using the clutch mechanism. The power transmitted to the pulley gear 15 is supplied from the pulley 16 coaxially fixed to the pulley gear 15 to the reel stand on either the supply side or the winding side by a drive switching unit having a swing mechanism.

In this embodiment, by incorporating a clutch mechanism on the capstan side, it is possible to supply a torque suitable for each mode, reducing the number of parts near the reel stand and simplifying the manufacturing process. Can be realized.

Further, in this embodiment, the friction clutch using the felt is used as the means for realizing the clutch effect, but there is no problem even if a means such as a magnet clutch by the attractive force of the magnet is used.

[0024]

As described above, according to the present invention, by providing a capstan with a plurality of clutch mechanisms with a simple structure, it is possible to generate a torque suitable for its operation. Further, a clutch structure is not required on each of the supply side and take-up side reel bases, and the number of assembling steps for each reel base is reduced and the component accuracy error management is facilitated.

Further, by stacking the clutch discs, the power can be transmitted according to the required transmission torque, and since the clutch discs are built in, they can be used together to protect the mechanism in the event of an abnormality.

[Brief description of drawings]

FIG. 1 is a structural diagram showing a capstan device according to an embodiment of the present invention.

FIG. 2 is a structural diagram showing reels on a supply side and a winding side in the embodiment of FIG.

FIG. 3 is an explanatory diagram of a reproduction mode in the embodiment of FIG.

FIG. 4 is an explanatory diagram of a reverse reproduction mode in the embodiment of FIG.

5 is an explanatory diagram of a fast-forwarding and rewinding mode in the embodiment of FIG.

FIG. 6 is a structural diagram showing a conventional capstan.

FIG. 7 is a structural diagram showing conventional supply-side and rewind-side reels.

[Explanation of symbols]

1 ... Capstan shaft, 1a ... Capstan shaft end, 1b ...
Capstan shaft end portion, 2 ... Bushing, 3 ... Rotor yoke, 4 ... Starter coil, 5 ... Rotor magnet, 6 ...
Mounting plate, 7 ... Bearing bearing, 8 ... Bearing, 9 ... Housing, A ... Clutch disc, B ... Clutch disc, Am ... Suction magnet, Bm ... Suction magnet, Af ... Clutch felt, Bf ... Clutch felt.

Claims (2)

[Claims] 1. A capstan shaft disposed as a rotary shaft of a direct drive motor, a rotor yoke coaxially fixed to the capstan shaft, a rotor magnet fixed to the rotor yoke, and a surface facing the rotor magnet, An attraction magnet having a rotation center coaxial with the capstan shaft and a rotation center coaxial with the capstan shaft are disposed between the rotor yoke and the attraction magnet to provide a clutch effect. And a clutch member having the capstan device. 2. A capstan shaft provided as a rotary shaft of a direct drive motor, a rotor yoke coaxially fixed to the capstan shaft, a rotor magnet fixed to the rotor yoke, and a surface facing the rotor magnet, A first disc for a clutch, which has a rotation center coaxial with the capstan shaft and a rotation center coaxial with the capstan shaft, and which is disposed on the disc-side surface of the rotor yoke.
And a rotation center coaxial with the capstan shaft.
And a second magnet for a clutch facing the surface of the capstan.