JPH0589570A - Guide roller for magnetic tape - Google Patents

Abstract

PURPOSE:To allow high-speed rotation and to eliminate run-out and rotational torque by subjecting a roller surface to electroless plating of a nickel system contg. tetrafluoroethylene. CONSTITUTION:The roller 1 which consists of aluminum or a soft alloy, such as free cutting brass, and is formed with the electroless plating layer 1A of the nickel system essentially consisting of the nickel contg. 15 to 30wt.% tetrafluoroethylene or contg. the nickel, phosphorus, etc., as components at a prescribed thickness on its surface is freely rotationally fitted onto a shaft 2 which consists of a stainless steel and is finished to <=1mum surface roughness. An upper flange 3 is press fitted to the upper part of the roller 1 and a lower flange 4 is press fitted to the lower part. Threads 4A are worked on the flange 4 and a screw driver groove 3A is worked on the flange 3. The guide roller for a magnetic tape having the excellent high-speed rotational performance and run-out accuracy is obtd. by this constitution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to recording using a magnetic tape such as a video tape recorder (hereinafter referred to as VTR),
The present invention relates to a guide roller for guiding the running of a magnetic tape in a reproducing device.

[0002]

2. Description of the Related Art In recent years, a magnetic tape recording / reproducing apparatus such as a VTR has come to perform high-speed reproduction of 20 times or more in addition to the conventional standard speed reproduction, and a head recording / reproducing track width of 20. The recording density is improved by narrowing it to less than a micrometer. Along with this, the guide rollers for magnetic tapes are required to rotate at high speed and with high precision without swinging.

An example of the above-mentioned conventional magnetic tape guide roller will be described below with reference to the drawings. FIG. 2 is a sectional view of a conventional magnetic tape guide roller.
A roller 5 made of a synthetic resin in which a small amount of oil is mixed with polyacetal is rotatably fitted on the shaft 6,
An upper flange 7 and a lower flange 8 are press-fitted in the upper part and the lower part, respectively. The lower flange 8 is provided with a screw 8A, and the upper flange 7 is provided with a driver groove for fixing the guide roller to a chassis (not shown) with a screw driver.

The operation of the magnetic tape guide roller having the above structure will be described below. When a magnetic tape (not shown) is wound around the roller 5 and starts running, the roller 5 in FIG. 2 rotates, and the upper and lower ends of the magnetic tape are guided by the upper and lower flanges 7 and 8 to run stably.

[0005]

However, the above-mentioned structure has the following problems. In a VTR or the like, high-speed reproduction is performed in addition to normal recording / reproduction. At this time, the roller 5 rotates at a high speed of about 10,000 RPM. As a result, the conventional resin roller 5 may be subject to thermal distortion and become heavy in rotation, or the outer peripheral runout may occur due to deformation, resulting in poor jitter performance in a VTR or the like.

[0006]

In order to solve the above problems, the guide roller for a magnetic tape of the present invention comprises a roller made of free-cutting soft metal having good heat resistance and having tetrafluoroethylene (hereinafter Nickel-based electroless plating having PTFE) is applied.

[0007]

According to the present invention, with the above-described structure, it is possible to obtain a magnetic tape guide roller which can be stably rotated at a high speed.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic tape guide roller according to an embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a sectional view of a magnetic tape guide roller of the present invention. Shaft 6 made of stainless steel, etc., with a surface roughness of less than 1 micrometer and a diameter of 1 to 1.5 mm
Is made of a soft metal such as aluminum or free-cutting brass, and the surface contains nickel powder containing 15 to 30% by weight of PTFE powder having a particle size of about 1 micrometer and a thickness of 3 to 20 micrometer. The nickel-based electroless plating layer 1A is applied, and the roller 1 having a diameter of 3 to 5 mm is rotatably fitted therein. An upper flange 3 is press-fitted in the upper part of the roller 1, and a lower flange 4 is press-fitted in the lower part. The lower flange 4 is processed with a screw 4A, and the upper flange 3 is processed with a driver groove 3A for fixing this guide roller to a chassis (not shown) with a screw driver.

The operation of the magnetic tape guide roller configured as described above will be described below with reference to FIG. When a magnetic tape (not shown) is wound around the roller 1 and starts running, the roller rotates, and the upper and lower ends of the magnetic tape are guided by the upper and lower flanges 3 and 4 to run stably. At this time, since the guide roller of the present invention has the roller 1 made of metal, it does not undergo thermal deformation even at high speed rotation of 10,000 rpm or more, so that the deformation does not cause runout or the rotation becomes heavy. Further, since the surface of the shaft 2 is smoothly processed and the surface of the roller 1 is coated with a nickel-based plating layer containing PTFE having good lubricity, the coefficient of friction between the shaft 2 and the roller is 0.08. Good level of rotational sliding performance can be obtained, and good tape running performance can be obtained in VTR and the like.

As described above, according to this embodiment, no thermal strain is generated even when the motor is rotated at a high speed, and there is almost no increase in runout or change in rotational load torque.

The surface of the roller 1 may be the same even if the surface of the roller 1 is electrolessly plated with nickel or phosphorus having irregularities or a large number of fine holes and then the surface is impregnated with PTFE resin.

[0012]

As described above, according to the present invention, by applying nickel-based electroless plating containing PTFE to the surface of the roller, it is possible to obtain a guide roller for a magnetic tape which is excellent in high-speed rotation performance and has good runout accuracy. .

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a magnetic tape guide roller of the present invention.

FIG. 2 is a sectional view of a conventional magnetic tape guide roller.

[Explanation of symbols] 1 roller 1A electroless plating layer 2 shaft 3 upper flange 3A driver groove 4 lower flange 4A screw

Claims (2)

[Claims] 1. A shaft made of stainless steel and having a surface roughness of 1 micrometer or less, a roller rotatably attached to the outer periphery of the shaft and made of an aluminum alloy or a copper alloy, and the roller above and below the roller. A guide roller for a magnetic tape, which has an upper flange and a lower flange that are press-fitted and fixed to a shaft, and whose surface is plated with nickel-based electroless plating containing 15 to 30 wt% of tetrafluoroethylene powder. 2. The guide for magnetic tape according to claim 1, wherein the surface of the roller is subjected to nickel-based electroless plating having a large number of irregularities or a large number of fine holes, and the surface is impregnated with a tetrafluoroethylene resin. roller.