JPS60124004A - Tape drum device - Google Patents

Abstract

PURPOSE:To avoid the malformation of a resin-molded stator despite a high temperature and a high humidity and to avoid contact among parts without deteriorating the motor characteristics, by attaining a monolithic structure of the stator consisting of an energizing winding of plural phases and a rotary transformer at the fixed side. CONSTITUTION:The stators 13 consisting of energizing windings of plural phases sre energized successively to generate the revolving power between a permanent magnet 10 and the stator 13. Then a rotary part unit A consisting of the magnet 10, a rotary part rotary transformer 11, a rotary disk 3, a main shaft 4, a rotary drum 2 and a magnetic head 1 is revolved. Then the head 1 is revolved and video signals are transferred between the head 1 and a magnetic tape, and this transfer of video signals is carried out between the transformer 11 and a rotary transformer 12 of a fixed part. The transformer 12 has a small change of size despite an environmental change since the stator 13 is adhered directly to the transformer 12. Thus the change of size is reduced also with the stator 13. In this way, the desired characteristics of a motor is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a tape drum device for recording and reproducing video signals to and from a magnetic tape in a rotating magnetic head type magnetic recording and reproducing device.

Conventional structure and problems In recent years, magnetic recording and reproducing devices (hereinafter referred to as VTR) have become smaller and smaller.
As tape drum devices, which are the main components of VT'Rs, become lighter and more popular, there is a demand for smaller, lighter, and more easily mass-produced tape drum devices.

A conventional tape drum device will be described below with reference to the drawings. Figure 1 shows a cross-sectional view of a conventional tape drum device, in which 1 is a rotating magnetic head for recording and reproducing video signals, 2 is a rotating drum whose outer periphery guides the running of a magnetic tape (not shown), and 3 is a rotating magnetic head for recording and reproducing video signals. A rotating disk 4 that rotates integrally with the rotating drum 2 is a main shaft, and is rotatably supported by bearings 5a and 5b. Reference numerals 6 and 7 denote a fixed-side rotary transformer and a rotating-side rotary transformer [1-tally 1 to lance, respectively, which transmit and receive video signals between the rotating magnetic head 1 and a video processing circuit section (not shown).

Reference numeral 8 denotes an inner yoke made of a magnetic material, which fixes the rotating side rotary transformer 7 to the rotating disk 3 and forms a magnetic loop together with a permanent magnet to be described later. 9 is a stator in which excitation windings of multiple phases are molded with resin. 10 is a permanent magnet magnetized with multiple poles.

-2- The operation of the tape drum device configured as described above will be explained below. By sequentially exciting the stator 9 consisting of excitation windings of multiple phases, rotational force is generated between the permanent magnet 10 and the stator 9, and the permanent magnet 10, the inner yoke 8, the rotating part rotary transformer 7, and the rotation disc 3
, a rotating unit A consisting of a main shaft 4, a rotating drum 2, and a rotating magnetic head 1 rotates. As the rotating magnetic head 1 rotates, video signals are transferred to and from the magnetic tape, and video signals are transferred between the rotating magnetic head 1 and the video signal processing section through the rotary transformer 7 in the rotating section and the fixed section. This is done between the rotary transformers 6.

However, in the above configuration, the water absorption and thermal expansion coefficient of the resin molding the stator 9 are higher than that of the permanent magnet 10.
and the inner yoke 8, the stator 9 and the permanent magnet 101 or the stator 9 may
There is a problem that the inner yoke 8 comes into contact with the inner yoke 8. As a countermeasure to the above problem, the stator 9 and the permanent magnet 10
It is also possible to increase the clearance C1 between the stator 9 and the inner yoke 8 in advance = 3 - the clearance C2 between the stator 9 and the inner yoke 8, but such a measure would reduce the radial width t of the stator 9. However, there is also the disadvantage that the excitation winding cannot be set to a desired value, and the characteristics of the motor cannot be set to the desired value.

Purpose of the Invention The purpose of the present invention is to provide a motor without deteriorating its characteristics.
It is an object of the present invention to provide a tape drum device in which deformation of a resin molded stator is suppressed even in high temperature and high humidity, and in which parts do not come into contact.

Structure of the Invention In order to achieve the above object, the tape drum device of the present invention includes a rotating drum having a built-in rotating magnetic head, a fixed drum for guiding a magnetic tape around its outer periphery, and a device for transmitting and receiving signals to and from the rotating magnetic head. A rotary transformer consisting of a pair of rotating parts and a fixed part, and a multi-phase excitation winding, with an identical constant 4 constant integrally constructed with the fixed part of the rotary transformer, and a plurality of magnetized poles. As a result, the stator is less likely to deform even when the environment changes (especially in high temperature and humidity), resulting in an extremely efficient tape drum device. .

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 shows a sectional view of a tape drum device in an embodiment of the present invention. In FIG. 2, 1 is a rotating magnetic head for recording and reproducing video signals, 2 is a rotating drum whose outer periphery guides the running of a magnetic tape (not shown), and 3 is a rotating disk that rotates integrally with the rotating drum 2. , 4 is a main shaft, which is rotatably supported by bearings 5a and 5b. Reference numeral 11 denotes a rotating side rotary transformer, which is fixed to the rotating disk 3. 12 is a fixed side rotary transformer. A stator 13 is composed of excitation windings of multiple phases, and is bonded to the fixed rotary transformer 12. 10 is a permanent magnet provided with a plurality of magnetic poles.

-5- The operation of the tape drum device configured as described above will be explained below. Stator 1 consisting of multiple phase excitation windings
3 is sequentially excited, a rotating horn is generated between the permanent magnet 10 and the stator 13, and the permanent magnet 10, the rotating part rotary transformer 11, the rotating disk 3, the main shaft 4, the rotating drum 2, and the rotating magnetic head. Rotating unit 8 consisting of 1 rotates. The rotating magnetic head 1 rotates and the ll! Li image signals are exchanged, and video signals are exchanged between the rotating magnetic head 1 and the rotary transformer 11 in the rotating part and the rotary transformer 12 in the fixed part.

As described above, according to this embodiment, the stator 13 consisting of a plurality of excitation windings is directly bonded to the fixed side [1-tally transformer 12], so even if environmental changes occur (particularly in high temperature and humidity), the fixed side Since the temperature of the rotary 1-lance 12 and dimensional changes due to temperature changes are small, the stator 13 is less likely to change dimensionally. Therefore, the permanent magnet 10 and the stator 1
The radial clearance C1 with respect to the motor 6 can be kept as small as possible, the excitation winding of the stator 13 can be wound in large numbers, and the desired performance of the motor 6 - can be obtained.

FIG. 3 is a unit perspective view showing the state of adhesion between the stator 13 and the stationary rotary transformer 12. In the above embodiment, the stator 13 was directly bonded to the fixed rotary transformer, but the method of fixing the stator is not limited to bonding, and it may be integrally bonded to the fixed rotary transformer 12 using resin. May be molded.

Effects of the Invention As is clear from the above explanation, in the present invention, the stator made of excitation windings of multiple phases and the stationary rotary transformer are integrally configured, so that the stator is prevented from deforming due to changes in temperature and humidity. Therefore, the radial clearance between the permanent magnet and the stator can be made as small as possible, and the excitation winding of the stator can also be wound sufficiently, so that a motor with good characteristics can be constructed.

In addition, since the fixed part rotary transformer has a low passing magnetic flux density, it forms a magnetic loop with the permanent magnet, so there is no need for an inner yoke to form a magnetic loop as in the conventional example. This has the effect of simplifying the overall configuration.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional tape drum device, and FIG. 2 is a sectional view of a tape drum device according to an embodiment of the present invention.
FIG. 3 is a unit perspective view of the stator and fixed-side rotary transformer. 1... Rotating magnetic head, 2... Rotating drum, 3...
- Rotating disk, 10... Permanent magnet, 11... Rotating side rotary transformer, 12... Stationary side rotary transformer, 13... Stator. Agent Yoshihiro Morimoto-8- Figure 1 Figure 2 L/ Figure 3

Claims (1)

[Claims] 1. A rotating drum with a built-in rotating magnetic head, a fixed drum for guiding a magnetic tape around its outer periphery, and a rotary transformer that transmits and receives signals to the rotating magnetic head and consists of a pair of a rotating part and a fixed part. A tape drum device comprising: a stator comprising excitation windings of multiple phases and integrally constructed with a fixed portion of the rotary transformer; and a permanent magnet magnetized with multiple poles.