JPH0648590Y2 - Pinch roller device - Google Patents

Description

[Detailed Description of the Invention] Industrial field of application The present invention relates to recording / reproducing of a video tape recorder (hereinafter referred to as VTR) for recording a signal on a tape or reproducing a signal recorded on a tape. The present invention relates to a pinch roller device used in the device.

2. Description of the Related Art A conventional pinch roller device will be described with reference to FIG. FIG. 3 is a side sectional view of a conventional pinch roller device.

In FIG. 3, a cylindrical elastic body 2 made of, for example, rubber is integrally attached to the outer circumference of the cylindrical holder 1, and an outer ring 3a of the ball bearing 3 is attached to the inner circumference of the cylindrical holder 1. It is sandwiched and fixed by the step portion 1a of the cylindrical holder 1 and the sleeve 4 fitted to the inner peripheral portion of the cylindrical holder 1. On the other hand, the inner ring 3b of the ball bearing 3 fitted in the small diameter portion 5a of the support shaft 5 is fixed by the stopper 6 fitted in the small diameter portion 5a of the support shaft 5.

In the ball bearing 3 of the pinch roller 7 configured as described above, the ball 3c, the outer ring 3a, and the ball 3c
So-called rattling occurs between the support shaft 5 and the pinch roller 7 by the amount of the gap between the inner ring 3b and the inner ring 3b, which is the amount of self-alignment.
Therefore, in order to transfer the tape by the cooperation of the pinch roller 7 and the capstan (not shown), when the pinch roller 7 is pressure-bonded to the capstan via the tape (not shown) with a predetermined force, Therefore, even if the support shaft 5 of the pinch roller 7 is not parallel to the capstan, the pinch roller 7 is uniformly pressed along the inclination of the capstan by the self-aligning action by the self-aligning amount. Good tape transfer can be realized.

Further, in the bearing portion of the pinch roller device, copper, iron, tin,
A pinch roller device using a sliding bearing made of a sintered oil-impregnated alloy whose raw materials are lead, zinc, nickel, etc.
As shown in Japanese Patent Laid-Open No. 58-155559, a spherical concave portion centered on the axis of the roller shaft is formed on the inner peripheral surface of the metal sleeve, while the roller shaft is rotatably and slidably fitted to the spherical recess. A pinch roller device has been proposed in which a spherical surface portion corresponding to the above is formed on the lower peripheral surface of a bearing member made of an oil-impregnated alloy and a self-aligning action is realized by sliding contact between both spherical surface portions.

However, in the pinch roller device configured as described above, the bearing portion has the following problems.

First, in the case of a pinch roller device using a ball bearing in the bearing part, (1) the pinch roller device performs an automatic centering function by utilizing the clearance between the inner ring, the ball, and the outer ring of the ball bearing. Therefore, since the range of automatic alignment is determined by the ball bearing used, there is little room for selection of the automatic alignment amount, and when determining the automatic alignment amount, the ball bearing must be selected. Increase, leading to higher costs.

(2) The cost is increased by using the ball bearing.

There was a problem such as.

Next, in the case of a pinch roller device that uses a sintered oil-impregnated alloy for the slide bearing in the bearing portion, (1) the bearing member rotates around the fixed shaft, which is the original operating mechanism of the sintered oil-impregnated alloy. The frictional heat is generated due to the unevenness of the surface of the shaft and the bearing, and the frictional heat causes the temperature of the bearing part to rise, which reduces the viscosity of the oil impregnated inside the bearing and makes it easier for it to flow. The temperature rise of the mechanism that lubricates the sliding surface of the roller bearing gradually and the temperature rise is slower than when the shaft rotates around the fixed bearing, so the initial rotation characteristics of the pinch roller deteriorate and It causes unevenness.

(2) Further, a coil spring for elastically restraining the shaft member from above is required to hold the bearing member at a predetermined position, and for this reason, a metal sleeve in which the roller shaft and the elastic member are fixed to the outer peripheral surface is required. There is a possibility of a relative vertical displacement between the tape and the tape, and the tape is not transported stably.

There was a problem such as.

In view of the above problems, the present invention realizes stable tape transfer even when the capstan and pinch roller support shafts are not parallel to each other, has a large setting range of the alignment amount, and has excellent initial characteristics. (EN) Provided is a pinch roller device which has a long life and is inexpensive.

Means for Solving the Problems In order to solve the above-mentioned problems, a pinch roller device of the present invention comprises a cylindrical support member having a cylindrical bearing fitted on an upper inner peripheral surface thereof, and a cylindrical shape. A rotary pair supporting member consisting of a cylindrical portion on the outer peripheral side and a substantially circular column on the inner peripheral side so as to form an annular groove at the lower end, and at least the cylindrical portion has a cylindrical elastic member fixed to its outer peripheral surface, And the inner peripheral surface of the support member is arranged so as to be spaced from and opposed to the outer peripheral surface of the support member,
The substantially cylindrical shape is configured such that the outer peripheral surface thereof is rotatably loosely fitted on the inner peripheral surface of the bearing of the support member.

Action With the above-described configuration, the present invention realizes stable tape transfer even if the capstan and pinch roller support shafts are non-parallel by the self-aligning action due to the gap between the inner peripheral surface of the bearing and the substantially cylindrical shape. Thus, it is possible to provide a pinch roller device that has a wide setting range of the amount of alignment, has excellent initial characteristics, has a long life, and is inexpensive.

Embodiment An embodiment of the pinch roller device of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view of an embodiment of the pinch roller device of the present invention, and FIG. 2 is an operation explanatory view of a bearing portion used in an embodiment of the pinch roller device of the present invention.

In FIG. 1, the pinch roller device 7 includes a metallic rotating body support member 11 made of a magnetic material and having a substantially cylindrical portion 9 and an annular groove portion 10 formed substantially in the center, and a cylindrical bearing 8 on the inner peripheral surface. The rotating body support member 11 is fixed to the cylindrical elastic member 12 made of rubber or the like by means of adhesion, baking, press fitting, or the like on the outer peripheral surface. And the inner peripheral surface of the support member 13 is spaced apart from and opposed to the outer peripheral surface of the support member 13, the first cylindrical portion 10a, the hollow second cylindrical portion 10b separating the annular groove portion 10, and the outer peripheral surface are supported. The bearing 8 is fitted in the member 13 and is rotatably fitted to the inner peripheral surface 8a of the bearing 8 and is composed of a first cylindrical portion 10a and a cylindrical portion 9 arranged to form the annular groove portion 10. Has been done. Further, the support member 13 is formed integrally with the rotor support member 11 and the support member 13 by providing the permanent magnet 14 at a position axially opposed to the substantially cylindrical portion 9 of the rotor support member 11.

The bearing 8 of the pinch roller device is made of a sintered oil-impregnated alloy. By setting the gap distance between the inner peripheral surface 8a of the bearing 8 and the outer peripheral surface of the substantially cylindrical portion 9 of the rotor support member 11 to a predetermined length, or by the lower half portion 8b of the inner peripheral surface 8a of the bearing 8. Is processed into a concave spherical shape, and the lower half portion 10c of the substantially cylindrical portion 9 of the rotary member support member 11 is processed into a convex spherical shape or a tapered shape, whereby the pinch roller device is allowed to tilt within a predetermined angle range. It is configured to allow.

In the pinch roller device configured as described above, when a tape is sandwiched between the pinch roller device and the capstan, the rotational force of the capstan is transmitted to the pinch roller device. Accordingly, in the pinch roller device, the rotor support member 11 is a support member.
Rotating around 13, the pinch roller device drives the tape, but at this time, even if the capstan and the support member 13
Even if there is no parallelism between the capstan and the pinch roller device, it is possible to maintain the parallelism between the capstan and the pinch roller device by the above-mentioned aligning action, and the pinch roller device uniformly presses along the inclination of the capstan. Therefore, good tape transfer can be realized.

Further, since the bearing 8 is fixed and the substantially cylindrical portion 9 rotates, frictional heat is generated due to the unevenness of the surface of the substantially cylindrical portion 9 and the bearing 8, and the frictional heat raises the temperature of the bearing 8 and the bearing 8 The viscosity of the oil impregnated in the inside of the bearing decreases and the oil easily flows, and thermal expansion helps, and the oil gradually exudes to the sliding surface of the bearing 8 to lubricate it. Further, the load on the bearing 8 is applied to the contact portion of the substantially cylindrical portion 9 and the substantially cylindrical portion 9 of the bearing 8 is abutted.
When no force is applied to the portion which is not in contact with, and when the substantially cylindrical portion 9 starts to rotate, a force is exerted such that oil is gathered to the portion where no load is applied. A part of this oil adheres to the surface of the substantially cylindrical portion 9 and is carried, and is dragged by this oil to move a larger amount of oil. In this way, the oil is sent into the gradually narrowing gap in the vicinity of the contact portion of the substantially cylindrical portion 9 with the bearing 8, and finally, into the contact portion of the substantially cylindrical portion with the bearing 8 where lubrication is most necessary. Reach As a result, as shown in FIG. 2, the oil flows toward the contact portion of the substantially cylindrical portion 9 that receives the high pressure from the low hydraulic pressure portion with the bearing 8, and the wedge of the oil caused by the oil flow is substantially reduced. A force for separating the substantially cylindrical portion 9 from the abutting portion of the cylindrical portion 9 with the bearing 8 is generated, and it functions to prevent the metals from contacting each other. When the movement reaches equilibrium, the flow of the oil that enters causes the approximately cylindrical portion 9 to be biased in the rotational direction, and the load that is pressed against the capstan motor shaft (not shown) of the pinch roller device causes the approximately cylindrical portion 9 to move. The thickness of the oil film on the bearing 8 is reduced, and as a result, the hydraulic pressure distribution A on the inner peripheral surface 8a of the bearing 8 becomes a sill as shown in FIG. Therefore, the bearing 8 made of a sintered oil-impregnated alloy
Will have good rotary bearing performance.

As described above, according to the present embodiment, the capstan and the pinch roller support shafts are not moved by the self-aligning action due to the gap between the inner peripheral surface 8a of the bearing 8 and the substantially cylindrical portion 9 of the rotating body support member 11. Even if they are parallel, stable tape transfer is realized, the setting range of the alignment amount is large, the initial characteristics are excellent, and the life is long.

Effects of the Invention As described above, the cylindrical supporting member having the cylindrical bearing fitted on the inner surface of the upper portion and the cylindrical portion formed on the outer peripheral side so as to form the annular groove at the lower end thereof. And a rotation-pair supporting member integrally formed with a substantially cylindrical portion on the inner peripheral side, at least the cylindrical portion has a cylindrical elastic member fixed to the outer peripheral surface thereof, and the inner peripheral surface thereof has the outer periphery of the supporting member. Away from the surface,
Since the substantially cylindrical portions are arranged so as to face each other, and the outer peripheral surfaces thereof are rotatably loosely fitted to the inner peripheral surface of the bearing, a gap between the inner peripheral surface of the bearing and the substantially cylindrical portion is formed. The self-aligning function enables stable tape transfer even if the capstan and pinch roller support shafts are not parallel, and has a large setting range for the centering amount, excellent initial characteristics, and long life. Moreover, the present invention provides an inexpensive pinch roller device.

[Brief description of drawings]

1 is a side sectional view of an embodiment of the pinch roller device of the present invention, FIG. 2 is a schematic view of a bearing portion of the pinch roller device, and FIG. 3 is a side sectional view of a conventional pinch roller device. 8 ... Bearing, 9 ... Substantially cylindrical portion, 10 ... Annular groove portion, 10a ...
... first cylindrical portion, 10b ... second cylindrical portion, 11 ... rotating body supporting member, 12 ... cylindrical elastic member, 13 ... supporting member.

Claims (1)

[Scope of utility model registration request] 1. A cylindrical support member having a cylindrical bearing fitted on the upper inner peripheral surface, and a cylindrical portion and an inner peripheral surface on the outer peripheral side so as to form an annular groove at the lower end of the cylindrical support member. A rotating body support member integrally formed with a substantially cylindrical body on the side, at least the cylindrical portion has a cylindrical elastic member fixed to the outer peripheral surface thereof, and the inner peripheral surface thereof is the outer peripheral surface of the supporting member. A pinch roller device, wherein the pinch roller device is arranged so as to be spaced apart and opposed to each other, and an outer peripheral surface of the substantially cylindrical column is loosely rotatably fitted to an inner peripheral surface of a bearing of the support member.