JPS63102012A - Magnetic reproducing and recording device - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rotary head type magnetic recording/reproducing device, and particularly to a device suitable for coupling a rotating shaft of a VTR to a rotating cylinder or a motor.

[Conventional technology]

FIG. 2 shows a conventional VTR cylinder. A disk 3 is fixed to the upper end of the shaft 1, and an upper cylinder 2 is attached to this disk 3.

A magnetic head 12 is attached to the upper cylinder 2 on the circumference. A lower cylinder 4 is provided below the upper cylinder 2 via a shaft 1 and a bearing 8. The lower cylinder 4 is fixed to the chassis part. A motor rotor 13 is provided at the lower end of the shaft 7) through a preload fitting 11, and drives the upper cylinder 2. The method for fixing the disk 3 to the shaft 1 is performed by shrink fitting, press fitting, or the like in terms of accuracy. The method of fixing the preload fitting 11 and the shaft 1 is as follows.
For ease of assembly, they are usually screwed together. Note that related to this type of device is Patent No. 4,647,65 for an upper rotating cylinder.

[Problem that the invention seeks to solve]

In the conventional method of fastening a rotating body such as a VTR cylinder to a rotating shaft, sufficient consideration has been given to problems regarding strength. However, little attention was paid to the boundary conditions of the fastening section. There are various methods for fastening parts, such as shrink fitting, press fitting, and screw fastening, but in all of these methods, the fastening is not uniform over the entire fastening group, but due to machining accuracy 9 surface roughness, etc. This caused variations and temperature changes. In particular, V T
In the R cylinder, this variation in the boundary conditions at the fastening section was manifested as a change in the spring constant and a change in the natural frequency of the cylinder design. In VTRs and cylinders, it is known that when the n-dimensional component of the motor rotation speed approaches the natural frequency of the screw thread of the cylinder system, resonance occurs and jitter worsens. In the design, the natural frequency of the screw is designed to avoid this n-order component, but due to the variation in the natural frequency or temperature change caused by the fastening parts mentioned above, some of the manufactured products It was inevitable that something with bad jitter would come out.

Conventionally, these jitter-defective products have been dealt with by replacing the rotor or cylinder, or by adjusting the preload on the bearing, but these methods have problems with walking and other issues. Ta.

An object of the present invention is to provide a magnetic recording/reproducing device that can stably fasten a rotating body with respect to machining accuracy, surface roughness, and temperature changes.

[Means for solving problems]

The above object is achieved by coupling the rotating shaft and the rotating body, in other words, the shaft, the rotating cylinder, and the motor by fitting together, and providing a gap in the middle of the coupling parts.

[Effect]

The contact area between the rotating body and the rotating shaft is stabilized by providing a gap in the intermediate portion of the fastening portion between the rotating body and the rotating shaft. Providing a gap in the fastening portion in this way limits the fastening area and increases the fastening force per unit, making the fastening method stable against processing errors and temperature changes. By applying this to a VTR cylinder, variations in p, natural frequency, and temperature changes can be kept small, making it easy to design a cylinder that avoids resonance.

〔Example〕

Hereinafter, an embodiment of the present invention applied to a VTR will be explained with reference to FIG. Figure 1 shows an overview of a VTR cylinder. The rotating cylinder is divided into an upper cylinder part, a lower cylinder part, and a motor rotor part. A disk 3 is fixed to one end of the shaft 1.

A motor rotor 13 is attached to the other end of the shaft 1 through a preloading tool 11. Disc 3 and preload fitting 1
A bearing 8 is provided between the two. The lower cylinder 4 is attached to the fixed side of the bearing 8.)
, the lower cylinder is fixed to the 4-digit VTR body. An FG base 6 and an S core 10 are attached to the cylinder 4, and the S core 10 is connected to a main magnet 9 attached to a portion facing the 8 cores 10 of the motor rotor 13.
The motor system is made between the two companies. An FG magnet 7 is provided above the main magnet 9, facing the FG base 6, and detects rotational components. An upper cylinder 2 is attached to the disk 3 and rotates together with the motor rotor. At the end of the upper cylinder 2 on the lower cylinder 4 side,
Two to four magnetic heads 12 are attached on the circumference. A lead 14 is provided around the outer periphery of the lower cylinder 4, and the magnetic tape is wound around the upper cylinder 2 and the lower cylinder 4 along this lead 14 and fed at a relatively low speed. On the other hand, the plurality of magnetic heads 12 attached to the upper cylinder 2 are rotating at high speed. Therefore, a helical magnetic information area is formed on the magnetic tape at an angle of ') -)'' 14, and image signals are recorded and reproduced.

The image signal is transmitted to the lower part of the disk 3 and a pair of rotary transformers 5 provided in the lower cylinder 4 between them.
It is transferred from the one rotation side to the fixed side.

The feature of this embodiment is that there is a gap 1 between the disk 3 and the preload fitting 11.
5 was established. This is shown in FIG. The disk 3 is fixed to the shaft 1 by shrink fitting or press fitting. Normally, in cases where there is no @15, these fixing conditions are not constant due to variations in processing accuracy 9 assembly conditions, etc. Further, the preload fitting 11 is screwed to the shaft 1.

of If there is no gap 15, the pressing tool will be damaged due to machining accuracy.

Fixing conditions vary depending on assembly conditions. Although these differences do not significantly affect the strength, they greatly affect the torsional natural frequency of the system, sometimes causing resonance problems and adversely affecting jitter.

Regarding the temperature characteristics, the normal disk 3 without the gap 15
The preload fitting 11 is unstable and causes a change in the natural frequency. As in this embodiment, if a gap 15 is provided at the contact portion of the disc 3 or the preload fitting 11 with the shaft 1, the contact portion can be limited, and the initial variation in natural frequency due to assembly and temperature characteristics are also reduced. It can be suppressed. This makes it easy to design a device that avoids resonance.

FIG. 3 shows an embodiment in which a gap 15 is provided in the rotating shaft 16. If there is no problem with the shaft strength, the same effect as when the gap 15 is provided on the rotating body 17 side can be expected.

FIG. 4 shows an embodiment in which the rotating body 17 is provided with a through screw hole 18 and fastened with a screw 19. screw hole 18
There may be more than one in the circumferential direction or in the axial direction, and the effect will be greater than in the case of a single one.

〔Effect of the invention〕

According to the present invention, it is possible to securely connect a rotating cylinder or a motor to a rotating shaft. In this way, variations in accuracy or changes in the natural frequency of the screw 9 due to temperature can be suppressed, and a design that avoids resonance between the rotational component and the torsion natural frequency becomes easy.

[Brief explanation of the drawing]

FIG. 1 is an embodiment of a VTR cylinder according to the present invention, FIG. 2 is a sectional view of a conventional VTR cylinder, and FIGS. 3 and 4 are other embodiments of the present invention. ...Upper cylinder, 3...Disk, 4...Lower cylinder, 5
...Rotary transformer, 6...FG base, 7...
F'G magnet, 8... Bearing, 9... Main magnet, 10... S core, 11... Preload fitting, 12... Magnetic head, 13... Motor rotor, 1
4... Lead, 15... Gap, 16... Rotating shaft,
17 First cause second self

Claims (1)

[Claims] 1. Consisting of a rotating shaft, a rotating cylinder fastened to the rotating shaft, a magnetic head provided on the rotating cylinder, and a motor fastened to the rotating shaft and driving the rotating cylinder. In the magnetic recording/reproducing device, a fastening part between the rotary shaft and the rotary cylinder and a fastening part between the rotary shaft and the motor are fitted together, and a gap is provided at an intermediate part of the fastening part on the side of the rotary cylinder. A magnetic recording/reproducing device characterized by: 2. A magnetic recording and reproducing device according to claim 1, characterized in that a gap is provided on the motor side at an intermediate portion between a fastening portion between the rotating shaft and the motor. 3. In claim 1, the fitting connection at the fastening portion between the rotary shaft and the rotary cylinder and the fastening portion between the rotary shaft and the motor may be a tight fit or a press fit. 1. A magnetic recording and reproducing device characterized in that the magnetic recording and reproducing devices are coupled together. 4. In claim 1, the fitting connection at the fastening part between the rotary shaft and the rotary cylinder and the fastening part between the rotary shaft and the motor is a connection by a clearance fit, and A magnetic recording/reproducing device characterized in that a through screw hole is provided in the radial direction on the motor side, and screws are secured using this hole.