JPS59217221A - Fitting method of video head disk - Google Patents

Abstract

PURPOSE:To fit a video head disk without requiring center deviation confirmation by forming a positioning part to such size that it is inserted into a hole part when a video head disk is heated, and assembling the video head disk to a rotating shaft assembly in the heated state. CONSTITUTION:The external diameter phid of the positioning part 28 and the internal diameter phiD of the hole part 22 are finished so as not to insert the positioning part 28 into the hole part 22 at room temperature, and when the video head disk 20 is heated and the hole part 22 increases in internal diameter phiD, the positioning part 28 is inserted into the hole part 22. When this video head disk 20 constituted as mentioned above is assembled to the rotating shaft assembly 23, the video head disk 20 is fitted while increased in the internal diameter phiD of the hole part 22 by being heated and only fixed with screws 29, etc. Namely, the video head disk 20 and positioning part 28 come into complete contact at room temperature, so the video head disk is assembled to the rotating shaft assembly without confirming whether there is center deviation or not.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a magnetic recording/reproducing device, and more particularly to an improvement in a method for mounting a video head disk having a magnetic head on the outer periphery.

[Technical background of the invention]

A magnetic recording/reproducing device (VTR) using the helical scan method.
), a plurality of magnetic heads are provided around the outer periphery of a video head disk, and as the video head disk rotates, the magnetic head rotates, thereby recording and reproducing magnetic tape.

Conventionally, this video recording disk has been attached to a rotating shaft in the manner shown in FIGS. 1 and 2.

1 has a plurality of magnetic heads 2 on the outer periphery and a hole 3 in the center.
This is a video head disk with a perforation.

Reference numeral 4 denotes a rotating shaft assembly consisting of a rotating shaft 7 rotatably held by a bearing 6 provided on the lower guide drum 5, and a flange 8 fixed to this rotating shaft 7.

The video head disk 1 has its hole 3 connected to 7 lunges 8.
It is installed in a predetermined position of the rotary shaft assembly 4 by inserting it into a positioning portion 9 formed in the rotary shaft assembly 4 and fixing it to the flange 8 with a screw lO.

[Problems with background technology]

However, in the conventional method described above, since the video head disk 1t needs to be smoothly fitted into the positioning part 9, it is necessary to set the inner diameter of the hole 3 to be larger than the outer diameter of the positioning part 9.

Therefore, as shown in FIG. 2, a gap δ is created between the video head disk 1 and the positioning portion 9, so that it is necessary to adjust the center runout before the disk 1 is completely fixed. That is, it was necessary to touch the dial gauge 11 to the outer edge of the disc 1 with the disc 1 temporarily secured to the 7th and 8th positions, check for center runout, and then secure the disc it. Therefore, when replacing the disk 1, the installation process becomes troublesome. Furthermore, even if the gap δ is made as small as possible within the range in which the disc 1 can be inserted, the value of core runout is larger than the required value calculated from the video signal, and the work of checking core runout cannot currently be omitted. there were.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned drawbacks of the conventional art, and provides a method for mounting a video head disk that allows the video head disk to be mounted without the need for checking for core runout. The purpose is to

[Summary of the invention]

Therefore, in the present invention, the positioning part of the hole part of the video head disk and the positioning part of the flange are set in such a state that the positioning part cannot fit into the hole part at room temperature, and the video head disk is heated to adjust the size of the hole part. The above objective was achieved by forming the video head disk to a size that would allow it to be inserted into the positioning part or hole when the video head disk was increased, and by attaching it to the rotating shaft assembly while the video head disk was heated. There is.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail below with reference to FIGS. 3 and 4f.

The disk is a video head disk having a magnetic head 21 provided on its outer periphery, and a hole 22 having an inner diameter φD is bored in the center of the disk.

The yoke is a rotating shaft assembly consisting of a rotating shaft 26 rotatably held by a bearing δ provided on a lower guide drum 24, and a flange 27 centered on the rotating shaft 26,
A positioning portion 28 having an outer diameter φd and having the rotating shaft 26 as its center is formed to project from the center of the flange n. The outer diameter φd of the positioning portion 28 and the inner diameter φD of the hole 22 are such that the positioning portion 28'f cannot be inserted into the hole 22 at room temperature. When the inner diameter φD of the hole portion 22 increases due to heating, the positioning portion 28 is dimensioned to be able to be inserted into the sixth portion 22.

When attaching the video head disk mount formed in this way to the rotating shaft assembly, the video head disk 2
If it is heated to 0 and the inner diameter φD of the hole n is expanded, it is inserted and fixed with screws 29, etc., and the legs are closed.

That is, at room temperature, the video head disk mounting and positioning section are in complete contact with each other, so the video head disk 20 can be attached to the rotating shaft assembly without checking for core runout.

〔Effect of the invention〕

As described above, if the present invention is used, the video head disk can be attached to the rotating shaft assembly without checking for core runout, so the video head disk replacement work becomes easy and the effect is great. There is something.

[Brief explanation of the drawing]

1 and 2 are explanatory diagrams showing a conventional method for installing a video head disk, and FIG. 1 shows a video head disk and rotating shaft assembly shown in the previous state. FIG. 2 is a sectional view showing a state in which center runout is being checked with a video head disk attached. 3 and 4 are explanatory diagrams showing the method of attaching the head disk to the video head according to the present invention. FIG. 3 is a sectional view showing the video head disk and rotating shaft assembly, and FIG. FIG. 3 is a sectional view showing a state in which the head disk is attached to the rotating shaft assembly chamber. 20...Video head disk 22...Hole 23...Rotating shaft assembly 27...Flange 28...Positioning department Attorney Kensuke Noriyuki (and 1 other person) Figure 1 Figure 3 Figure 2 No. 41″-1

Claims (1)

[Claims] The video head disk is attached to a predetermined position on the rotary shaft assembly by fitting the hole provided in the video head disk into the positioning portion provided on the flange of the rotary shaft assembly. When the hole of the video head disk and the positioning section of the seven lunges are set in such a state that the positioning section cannot be inserted into the hole at room temperature, and when the size of the hole is increased by heating the video head disk, The video head disk mounting system is characterized in that the positioning portion is formed in a size that allows it to be inserted into the hole, and the video head disk is attached to the rotating shaft assembly in a heated state. Method.