JP2000339645A - Rotary head drum device, and balance adjusting method for the device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust balance after the assembling of a rotary head drum device by adjusting the balance of a rotary drum from a hole connected to the rotary drum provided in a fixed drum. SOLUTION: A hole 20 connected to the bottom surface of a rotary drum 3 is provided in the bottom part of a fixed drum 2, and the balance of the rotary drum 3 is adjusted from this hole 20. For this balance adjusting work, a weight 21 made of a metallic plate (e.g. copper plate) is stuck by adhesive or the like to the bottom surface of the rotary drum 3, i.e., the attaching surface of a magnetic head 7. This weight 21 is stuck to a proper position considering the arrangement or the like of the magnetic head 7, the entire weight balance of the rotary drum 3 is adjusted to be smoothly rotated, and stable recording/ reproducing is carried out. This balance adjusting work is easily carried out through the hole 20 even after the complete assembling of the rotary head drum device 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary head drum device used in a magnetic recording / reproducing apparatus and a balance adjusting method in the rotary head drum device.

[0002]

2. Description of the Related Art FIG. 6 shows an example of a rotary head drum device used in a magnetic recording / reproducing apparatus.

The rotary head drum device 1 has a lower fixed drum 2 and an upper rotary drum 3 supported to rotate at a high speed with respect to the fixed drum 2 and to which a magnetic head 7 is attached. And the magnetic tape T
The signal is recorded or reproduced by traveling with the .wound at a predetermined angle. In the rotary head drum device 1, the magnetic tape T is run while being wound obliquely along the leads 4 formed on the peripheral surface of the fixed drum 2.

FIG. 7 shows the internal structure of the rotary head drum device 1. A shaft 5 is fixed upright at the center of the fixed drum 2, and a ball bearing 6 is attached to the shaft 5.
The rotatable drum 3 is rotatably supported via.

[0005] A plurality (three in this example) of magnetic heads 7 are mounted on the bottom side of the rotating drum 3 as shown in FIG. The magnetic heads 7 are attached to the tip of the head base 8, respectively, and the head base 8 is fixed to the rotating drum 3 by fixing screws 9 so that the magnetic head 7 slightly projects from the drum peripheral surface. It is.

A motor for rotating the rotating drum 3 at a high speed with respect to the fixed drum 2 is incorporated in the rotating drum 3 to which the magnetic head 7 is attached.

That is, this motor has a stator plate 1 provided with a plurality of coils 10 in the rotation direction of the rotating drum 3.
1 and annular rotor magnets 13 and 14 arranged so as to sandwich the stator plate 11 from above and below.

The stator plate 11 is fixedly connected to the upper end of the shaft 5 via a connecting member 12, while the rotor magnets 13, 14 face the coil 10 on yoke plates 15, 16 integrated with the rotating drum 3, respectively. So that it is fixed.

When the coil 10 is energized in the motor, the coil 10 and the rotor magnet 13
14, the rotor magnet 13,
The rotary drum 3 is driven to rotate with respect to the fixed drum 2 integrally with the fixed drum 2.

[0010] Rotary transformers 17 and 18 are attached to the fixed drum 2 and the rotary drum 3 so as to face each other on both sides. During recording or reproduction, the rotary trans- formers 17 and 18 are interposed therebetween. A signal is transmitted between the magnetic head 7 of the rotating drum 3 and the magnetic head 7.

[0011]

In this rotary head drum device, if the weight balance of the rotary drum 3 is not balanced due to the arrangement of the magnetic heads 7 and the like, smooth rotation of the rotary drum 3 is hindered. Since stable recording and reproduction cannot be performed, it is necessary to adjust the overall weight balance (dynamic balance) of the rotating drum 3.

However, in the conventional rotary head drum device, it is not possible to adjust the balance of the rotary drum 3 after assembling, so that it has been necessary to adjust the balance a plurality of times during the assembly process.

As described above, conventionally, since the balance adjustment is performed during the assembly of the rotary head drum device, there has been a problem that the mass productivity is low and the burden on equipment is large.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to make it possible to adjust the balance of the rotating drum after assembling the rotating head drum device, and to solve the above problems.

[0015]

In order to solve the above-mentioned problems, the present invention comprises a fixed drum, and a rotating drum supported to rotate at a high speed with respect to the fixed drum and having a magnetic head mounted thereon. In the rotating head drum device, a fixed drum is provided with a hole communicating with the rotating drum,
The hole allows the balance of the rotating drum to be adjusted.

In this case, a weight is stuck to a required portion of the rotary drum through the hole to adjust the balance of the rotary drum. Alternatively, a plurality of holding holes may be provided in the rotating drum, and a weight may be fitted into one or more of the holding holes through the holes to adjust the balance of the rotating drum.

By adjusting the balance of the rotary drum in this manner, the rotary drum can rotate smoothly, and stable recording and reproduction can be performed. This balance adjustment work can be easily performed through the hole of the fixed drum even after the rotary head drum device is assembled, which leads to improvement in mass productivity.

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIGS. 1 to 3 show a first embodiment of the present invention. The basic structure of the rotary head drum device 1 shown here is substantially the same as that of the conventional example shown in FIGS. 7 and 8 described above.

That is, the rotary head drum device 1 has a lower fixed drum 2 and an upper rotary drum 3 supported to rotate at a high speed with respect to the fixed drum 2 and to which a magnetic head 7 is attached. A signal is recorded or reproduced by traveling with the magnetic tape wound around the peripheral surface at a predetermined angle.

A shaft 5 is fixed upright at the center of the fixed drum 2, and a ball bearing 6 is mounted on the shaft 5.
The rotatable drum 3 is rotatably supported via.

A plurality (three in this example) of magnetic heads 7 are mounted on the bottom side of the rotating drum 3 as shown in FIG. The magnetic heads 7 are attached to the tip of the head base 8, respectively, and the head base 8 is fixed to the rotating drum 3 by fixing screws 9 so that the magnetic head 7 slightly projects from the drum peripheral surface. It is.

A motor for rotating the rotating drum 3 at a high speed with respect to the fixed drum 2 is incorporated in the rotating drum 3 to which the magnetic head 7 is attached.

That is, this motor has a stator plate 1 provided with a plurality of coils 10 in the rotation direction of the rotary drum 3.
1 and annular rotor magnets 13 and 14 arranged so as to sandwich the stator plate 11 from above and below.

The stator plate 11 is fixedly connected to the upper end of the shaft 5 via a connecting member 12, while the rotor magnets 13, 14 face the coil 10 on yoke plates 15, 16 integrated with the rotating drum 3, respectively. So that it is fixed.

When the coil 10 is energized in the motor, the coil 10 and the rotor magnet 13
14, the rotor magnet 13,
The rotary drum 3 is driven to rotate with respect to the fixed drum 2 integrally with the fixed drum 2.

Between the fixed drum 2 and the rotary drum 3, rotary transformers 17 and 18 are mounted on both sides of the fixed drum 2 so as to face each other. A signal is transmitted between the magnetic head 7 of the rotating drum 3 and the magnetic head 7.

In the rotary head drum device 1 constructed as described above, in particular, in the present invention, as shown in FIGS. 1 and 3, a hole 20 communicating with the bottom surface of the rotary drum 3 is provided at the bottom of the fixed drum 2. , The rotary drum 3 from this hole 20
The balance adjustment work can be performed.

In this embodiment, as shown in FIG. 2, a weight 21 made of a metal plate (for example, a copper plate) or the like is provided on the bottom surface of the rotating drum 3, that is, the mounting surface of the magnetic head 7, as shown in FIG.
With an adhesive or the like. The weight 21 is attached to an appropriate position in consideration of the arrangement of the magnetic head 7 and the like, whereby the weight of the rotating drum 3 is adjusted and smooth rotation becomes possible, and stable recording and reproduction is performed. Will be able to

The balance adjustment by attaching the weight 21 can be easily performed from the lower side of the fixed drum 2 through the hole 20 even after the rotary head drum device 1 is completely assembled. is there. This hole 20
It is desirable that the size is set to a size having some allowance so that the balance adjustment work of the rotary drum 3 (the work of attaching the weight 21) can be easily performed.

FIGS. 4 and 5 show a second embodiment of the present invention. Here, the description of the same parts as in the first embodiment described above is omitted, but the rotary head drum device 1 in this example is provided in the holding hole 22 provided in the rotary drum 3 as shown in FIG. The balance is adjusted by fitting a spherical weight 23.

As shown in FIG. 5, a plurality of holding holes 22 are arranged along the outer periphery of the rotating drum 3 so as to face the bottom surface of the rotating drum 3, ie, the mounting surface of the magnetic head 7, and one or more of the holding holes 22 are provided. A spherical weight 23 made of metal (for example, copper) or the like is press-fitted and held in a suitable holding hole 22 to adjust the overall weight balance of the rotating drum 3.

The balance adjustment by fitting the weight 23 can be easily performed from the lower side of the fixed drum 2 through the hole 20 even after the rotary head drum device 1 is completely assembled. .

In the above configuration, the spherical weight 2 is provided in the holding hole 22.
3 is press-fitted and fitted. Alternatively, for example, a structure in which the holding hole 22 is formed as a screw hole, and a weight made of a screw is screwed into the holding hole 22 and fitted to adjust the balance.

[0035]

As apparent from the above description, in the present invention,
By providing a hole in the fixed drum and adjusting the balance of the rotating drum from this hole, the balance of the rotating drum can be adjusted in one step after assembling the rotating head drum device. Improvements in mass productivity are expected, and there are effects such as a reduction in the burden on equipment.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a rotary head drum device showing a first embodiment of the present invention.

FIG. 2 is a bottom view of the rotary drum.

FIG. 3 is a bottom view of the fixed drum.

FIG. 4 is a longitudinal sectional view of a rotary head drum device showing a second embodiment of the present invention.

FIG. 5 is a bottom view of the rotary drum.

FIG. 6 is a perspective view of a rotary head drum device.

FIG. 7 is a longitudinal sectional view of a rotary head drum device showing a conventional example.

FIG. 8 is a bottom view of the rotary drum.

[Explanation of symbols]

1 ‥‥ rotating head drum device, 2 ‥‥ fixed drum, 3 ‥
{Rotary drum, 7} magnetic head, 20 holes, 21,
23 ‥‥ weight

Claims (6)

[Claims] 1. A rotary head drum device comprising: a fixed drum; and a rotary drum supported to rotate at a high speed with respect to the fixed drum and having a magnetic head attached thereto. A rotary head drum device, wherein a hole communicating with the drum is provided, and the balance of the rotary drum is adjusted from the hole. 2. The rotary head drum device according to claim 1, wherein a weight is attached to the rotary drum through the hole to adjust the balance of the rotary drum. 3. A rotary drum having a plurality of holding holes,
2. The rotary head drum device according to claim 1, wherein a weight is inserted into one or more holding holes through the holes to adjust the balance of the rotary drum. 4. A balance adjusting method in a rotary head drum device, comprising: a fixed drum; and a rotary drum supported to rotate at a high speed with respect to the fixed drum and having a magnetic head mounted thereon. A balance adjustment method for a rotary head drum device, wherein a hole communicating with the rotary drum is provided in the fixed drum, and the balance of the rotary drum is adjusted from the hole. 5. The balance adjustment method for a rotary head drum device according to claim 4, wherein a weight is attached to said rotary drum through said hole to adjust the balance of said rotary drum. 6. The rotating drum is provided with a plurality of holding holes, and a weight is fitted into one or more of the holding holes through the holes to adjust the balance of the rotating drum. Item 5. A balance adjusting method in the rotary head drum device according to Item 4.