JPH04349258A - Rotary drum device - Google Patents

Abstract

PURPOSE:To suppress the flow of air at the circumference of an upper drum and to suppress the wind blowing sound to occur due to the rotation of an upper drum by fitting a cover to cover the upper edge face and the flank of a rotary type upper drum. CONSTITUTION:At a lower drum 1, a motor 4 for rotating and driving an upper drum 2 is fitted and a rotary axis 6 is rotatably supported by a ball bearing 7. At the drum 1, a pedestal 8 is fixed and at the pedestal 8, a cover 3 is fixed by a bolt 9. The cover 3 is made of aluminium or the plastic resin, and the upper edge face and the flank of the drum 2 are formed to a shape where the lead of the drum 1 is separated by the magnetic tape width of the drum 1. Thus, the flow of the air of the circumference of the upper drum is suppressed, the wind blowing sound generated due to the rotation of the upper drum is suppressed, the generation of an air film generated between the upper drum and the magnetic tape can be reduced and the spacing loss is reduced.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating drum device equipped with a rotating upper drum used in a magnetic recording/reproducing device.

0002

2. Description of the Related Art A conventional rotating drum device has a structure as shown in FIG. 5, and is composed of a fixed lower drum 1 and a rotating upper drum 2. The diameter of the upper drum 2 is φ100mm,
When this upper drum 2 rotates at, for example, 9000 rpm, the speed at the inner side, that is, the rotation center point O, becomes 0 km/h,
The speed at the outside, ie, point A, is 170 km/h, which creates a speed difference. As a result, the air around the upper drum 2 is stirred and "wind noise" is generated. This principle is the same as the centrifugal pump shown in FIG.

0003

Problem to be Solved by the Invention The present invention has been made in order to suppress the "wind noise" which is a problem with the conventional art. An object of the present invention is to provide a rotating drum device that can reduce the amount of air film generated during the rotation.

0004

[Means for Solving the Problems] A rotary drum device equipped with a rotary upper drum according to the present invention is characterized in that a cover is attached to cover the upper end surface and/or side surface of the rotary upper drum.

[0005]

[Operation] By doing this, the flow of air around the upper drum can be suppressed.

[0006]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 3. Components that are the same as those described in the related art will be described with the same reference numerals. First, FIG. 1 is a sectional view of an embodiment of a rotating drum device according to the present invention, and FIG. 2 is a perspective view thereof. 1 is a fixed lower drum, and 2 is a rotating upper drum. 3 is a cover that covers the upper end surface and/or side surface of the upper drum 2, which is a feature of the present invention.

A motor 4 is attached to the lower drum 1 to rotate the upper drum. 5a is a rotary transformer on the fixed side. A rotating shaft 6 is rotatably supported by a ball bearing 7, and an upper drum 2 is attached to the opposite end of the rotating shaft 6 to which the rotor of the motor 4 is attached. 5b is a rotary transformer on the rotating side. A pedestal 8 is attached to the lower drum 1 by a bolt (not shown).
is fixed. The cover 3 is fixed to this pedestal 8 with bolts 9. This cover 3 is made of aluminum or synthetic resin, and is formed so that the upper end surface and side surface of the upper drum 2 are separated from the leads of the lower drum 3 by a magnetic tape width. Note that 10 is a video head.

The gap B between the side surface of the upper drum 2 and the cover 3 is
For example, the cover 3 is adjusted to have a thickness of 50 to 200 μm, and the cover 3 is fixed to the pedestal 8 with bolts 9. Figure 3
This is another embodiment of the rotating drum device of the present invention. The cover 3 covers only the upper end surface of the upper drum 2. FIG. 4 shows still another embodiment of the rotating drum device of the present invention. A cover 3 covers the side surface of the upper drum 2. The upper end surface of the upper drum 2 is exposed.

[0009]

As described above, the rotary drum device equipped with the rotary upper drum of the present invention has a cover that covers the upper end surface and/or side surface of the rotary upper drum. By doing so, the flow of air around the upper drum can be suppressed, resulting in the following effects. ■It is possible to suppress the "wind noise" caused by the rotation of the upper drum. ■Air film generated between the upper drum and the running magnetic tape can be reduced, reducing space loss.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of a rotating drum device of the present invention.

FIG. 2 is a perspective view of an embodiment of the rotating drum device of the present invention.

[Figure 3]
A perspective view of another embodiment of the rotary head device of the present invention

[Figure 4]
A perspective view of still another embodiment of the rotary head device of the present invention

[Fig. 5] Perspective view of a conventional rotating drum device

[Figure 6] Principle diagram of centrifugal pump

[Explanation of symbols]

1 Fixed lower drum 2 Rotating upper drum 3 Cover 4 Motor 5a, 5b Rotary transformer 6 Rotation axis 7 Ball bearing 8 Pedestal 9 bolts 10 Video head

Claims (1)

[Claims] 1. A rotary drum device comprising a rotary upper drum, characterized in that a cover is attached to cover an upper end surface and/or side surface of the rotary upper drum.