JP2530650Y2 - Take-up reel base rotation transmission mechanism - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a take-up reel table rotation transmitting mechanism of a magnetic recording and reproducing apparatus using a magnetic tape.

[0002]

2. Description of the Related Art A conventional take-up reel base rotation transmission mechanism is, for example, a motor (2) as shown in FIGS.
The torque is transmitted to the torque limiter (3) through the rubber belt (21) and the gear (23).
The torque limited to the specified value in (3) is changed from gear (6) to gear.
(61), (62), (63), and sequentially transmitted to the reel base (5), and the reel (7) on the reel base (5) rotates together with the reel base (5) to wind the magnetic tape. .

In the case of the above-mentioned mechanism, when used for a long period of time, there is a problem that the torque limited by the torque limiter (3) changes for the following reasons, resulting in a change in the final transmission torque.

The reason for this is that, as shown in FIG. 6, a torque limiter (3) has an input side gear (31) and an output gear (32) concentric with a shaft (30) protruding from a chassis (1). Deploy, both gears
(31) A friction member (33) such as felt is interposed between (32) and the input gear (31) is supported by a support plate (35) and a friction member (34) such as felt.
The friction members (33) and (34) wear and deteriorate due to long-term use, and the thickness of the friction members decreases. The spring (36) is extended by the reduced thickness, the surface pressure applied to the friction members (33) and (34) is reduced, and as a result, the transmission torque of the torque limiter (3) is reduced.

In the case of the torque limiter (3) having the above structure, the transmission torque also changes depending on the relative speed at which the friction members (33) and (34) slip. Generally, the higher the relative speed of the slip, the higher the torque. Further, the torque changes due to the temperature change, and when the temperature rises, the transmission torque decreases.

Therefore, in the conventional tape winding mechanism in which torque is controlled by using the slip mechanism shown in FIGS. 4 and 5, the winding torque cannot be kept constant over a long period of time or when the use environment is different. Was.

This is because it is difficult to realize a mechanism corresponding to a reduction in the thickness of a magnetic tape and a diversification of reproduction speed from a low speed to a high speed due to a long recording time of a magnetic recording / reproducing apparatus in recent years. I have to. The present invention clarifies a rotation transmission mechanism that can solve the above problem.

[0008]

The take-up reel base rotation transmission mechanism is
A torque limiter (3) constituted by a slip mechanism is provided in a rotation transmission gear train connecting the motor (2) and the take-up reel base (5), and the take-up reel base (5) is taken up. Transmits torque. A second torque limiter (4) that includes a slip mechanism in a rotation transmission gear train between the first torque limiter (3) and the take-up reel base (5) and applies a rotational load to the first torque limiter (3). ), And a torque obtained by subtracting the load torque generated by the second torque limiter (4) from the torque generated by the first torque limiter (3) is applied to the take-up reel base (5). Is done.

[0009]

[Operation and Effect] A torque obtained by subtracting the torque generated by the second torque limiter (4) from the torque generated by the first torque limiter (3) is transmitted to the take-up reel base (5). Even if the transmission torque decreases due to the wear of the slip member of the first torque limiter (3) or the like, the load torque also decreases due to the wear of the slip member of the second torque limiter (4) and the like. The applied torque hardly changes over time and in any environment. Therefore, a constant and stable torque can always be supplied to the reel stand (5) without using an expensive torque sensor or a complicated torque adjusting mechanism.

[0010]

1 and 2 show a rotation transmitting means of a magnetic recording / reproducing apparatus from a capstan motor (2) to a reel base (5) via a torque limiter (3).

In the same manner as in the prior art shown in FIGS. 4 and 5, rotation is transmitted from a capstan motor (2) for generating torque to a pulley (22) via a rubber belt (21) and is coaxial with the pulley. An input gear (31) of a known torque limiter (3) is meshed with a gear (23) provided so as to be able to rotate integrally with the pulley.

The output gear (32) of the torque limiter (3)
Gear of the second torque limiter (4), which is a feature of the present invention
(41) is engaged. The gear (41) rotates in the opposite direction to the output gear (32), and the rotation is transmitted from the gear (41) to the reel base (5) via the gears (61), (62) and (63). The reel (7) on the reel base (5) rotates integrally with the reel base and winds up a tape (not shown).

The second torque limiter (4) includes a chassis
A gear (41) is provided on a shaft (40) protruding from (1) so as to be rotatable and slidable in the axial direction, and a friction member (42) such as felt is provided between the gear (41) and the chassis (1). ), And a spring (44) is interposed between the support plate (43) and the gear (41) locked at the shaft tip,
The gear (41) is configured to be pressed toward the chassis (1).

The friction member (42) may be pressed against a fixing member instead of the chassis. The output gear of the torque limiter (3)
The gear (41) of the second torque limiter (4) and the output gear (32) may be indirectly engaged with the gear (32) via an intermediate gear (not shown).

The torque value limited by the torque limiter (3) is determined in consideration of the existence of the second torque limiter.
It is set a little higher than before.

However, as described above, the torque limiter
Even if the transmission torque decreases due to the wear deterioration of the friction members (33) and (34) of (3), the friction member of the second torque limiter (4)
(42) also wears and deteriorates, and the load is reduced. As a result, the torque transmitted to the reel base (5) hardly changes.

Depending on which part of the torque transmission mechanism the second torque limiter (4) is provided, or depending on the reduction ratio,
If the second torque limiter (4) and the torque limiter (3) change in the same manner, the torque transmitted to the reel stand (5) may change, but the second torque limiter (4) By properly selecting the strength of the spring (44) and the thickness of the friction member (42), it is possible to minimize the change in the torque transmitted to the reel stand (5).

The present invention is not limited to the configuration of the above embodiment, and various modifications can be made within the scope described in the claims for utility model registration.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a rotation transmission mechanism on a motor side.

FIG. 2 is a cross-sectional view of the rotation transmitting mechanism on a reel base side.

FIG. 3 is a sectional view of a second torque limiter.

FIG. 4 is a sectional view on the motor side of a conventional rotation transmission mechanism.

FIG. 5 is a cross-sectional view of a conventional rotation transmission mechanism on a reel base side.

FIG. 6 is a sectional view of a torque limiter.

[Explanation of symbols]

 (2) Motor (3) Torque limiter (4) Second torque limiter (5) Take-up reel base

Claims (2)

(57) [Scope of request for utility model registration] A torque limiter (3) constituted by a slip mechanism is provided in a rotation transmission gear train connecting between a motor (2) and a take-up reel base (5). 5) a take-up reel table rotation transmission mechanism for transmitting a take-up torque to a take-up reel base rotation transmission mechanism, wherein a slip mechanism is provided in a rotation transmission gear train between the first torque limiter (3) and the take-up reel base (5); A second torque limiter (4) for applying a rotational load to the first torque limiter (3) is provided, and a second torque limiter (4) is provided for the torque generated by the first torque limiter (3). A take-up reel base rotation transmitting mechanism, wherein a torque obtained by reducing a load torque generated by the take-up reel base (5) is applied to the take-up reel base (5). The second torque limiter (4) includes a gear (41) that meshes directly or via an intermediate gear with an output gear (32) of the first torque limiter (3) and a chassis (1) and the like. A friction member such as felt is sandwiched between the fixing member and the gear (4
2. The take-up reel base rotation transmission mechanism according to claim 1, wherein the take-up reel base rotation transmission mechanism is configured such that 1) is pressed toward the fixing member by a spring (44).