JPS6120688Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field This invention relates to a drum assembly for a magnetic recording and reproducing device (hereinafter referred to as a VTR).

BACKGROUND TECHNOLOGY In a VTR drum assembly, it is necessary to enable the magnetic tape wound helically around the drum to run along the circumferential surface of the drum in optimal contact and in complete contact with the video head. is necessary. Otherwise, reliable and good recording and playback operations cannot be performed. This drum assembly includes, for example, an upper drum and a lower drum, and is configured such that a video head supported by a head disk rotates along a slit formed between the two drums. Then, the video head slides into contact with the magnetic surface of the tape running along the circumferential surface of the drum, thereby performing recording and reproducing operations.

By the way, in such a drum assembly,
Conventionally, the following problems have occurred.

In other words, when the video head comes into sliding contact with the tape,
The head behaves as if it intermittently hits the tape running surface. As a result, the running tape may flutter and vibrate, or a so-called waving phenomenon may occur.
Therefore, the contact between the video head and the tape, that is, the adhesion, deteriorates, and the tape cannot run stably. As a result, good and reliable recording and playback operations cannot be performed. Furthermore, due to variations in processing accuracy and assembly accuracy, eccentricity during installation, etc., the drum rotating body vibrates during rotation as the video head rotates, which has an adverse effect on recording and playback operations.

In addition, it is necessary to efficiently dissipate heat from heat sources placed around the drum assembly, the motor that drives the video head, etc. to the outside, but conventional drum assemblies do not have sufficient heat dissipation measures. No consideration was given to this.

Disclosed in the invention This invention was made to solve the above-mentioned problems, and aims to improve the adhesion between the video head and the tape, suppress and reduce the vibration of the video head, and improve heat dissipation efficiency. The purpose is to provide a drum assembly.

In order to achieve this purpose, this invention includes a mounting fixture fitted via an elastic shock absorber to the rotating shaft that supports the video head, and a peripheral part elastically supported on the outer periphery of the fixture. A rotary fan mechanism that also serves as a dynamic damper is constructed by a rotating body having a plurality of blades, and this rotary fan mechanism is disposed inside an upwardly opening opening formed in the upper drum.

According to this invention, during recording and playback, air around the drum is sucked into the drum through the slits formed between the tape and the circumferential surface of the drum and between the upper and lower drums by the rotation of the rotating body. This suction action brings the running tape into close contact with the circumferential surface of the drum. Therefore, good tape contact can be obtained.

Moreover, since the rotating body is attached to the rotating shaft via an elastic buffer, and the rotating fan mechanism acts as a dynamic damper, it is possible to suppress and prevent the vibration of the drum rotating body caused by the rotation of the video head. It has vibration damping and anti-vibration effects.

In addition, the air sucked into the drum by the rotation of the rotating body is quickly discharged upward from the opening opening above the upper drum, so that a sufficient heat dissipation effect can be obtained. In particular, compared to those that radiate heat below the drum, it has a higher heat radiating effect on the motor and circuit system, and is an excellent heat radiation measure.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, one embodiment of the invention will be described in detail with reference to the drawings.

1 and 2 show the overall structure of the drum assembly of the present invention.

This drum assembly includes an upper drum 10,
It is generally composed of a lower drum 11 and a rotary drum 12 rotatably supported inside the drums 10 and 11.

The upper drum 10 and the lower drum 11 are connected and fixed together by a drum support 13 provided on a part of their peripheral surfaces and an upper plate 14 by screws or the like. A slit 15 of a predetermined width is formed between the two drums 10, 11, along which video heads 20, 20 rotate.

A bearing 1 is attached to the center boss portion 110 of the lower drum 11.
6 and 16 are provided, and a rotary shaft 17 is rotatably supported by the bearings 16 and 16 with its central axis coaxial with the lower drum 11. The rotating drum 12 is mounted above the bearing of the rotating shaft 17.

The rotating drum 12 includes a flange 18 fitted and fixed to the rotating shaft 17, a disc-shaped head disk 19 fixed to the flange 18, and a disk-shaped head disk 19 arranged at an interval of 180 degrees on the upper surface of the peripheral edge of the tip of the head disk 19. It consists of a pair of video heads 20, 20 mounted on the head. A small and thin DD (direct drive) motor 21 is disposed below the lower drum 11 and is connected to an end of the rotary shaft 17 that projects downward from the lower drum. By driving the motor 21, the video heads 20, 20 are rotated in a predetermined direction via the head disk 19.

The upper surface of the upper drum 10 is open, and the upper end of the rotating shaft 17 extends to the position of the opening 22. A tape guide 23 for guiding the tape A is provided on the circumferential surface of the lower drum 11 and inclined at a predetermined angle in the circumferential direction. The tape A is loaded onto the drums 10 and 1 by a loading mechanism (not shown).
The tape is wound helically around the circumferential surface of the drum along the tape guide 23, and runs diagonally with respect to the drum along the tape guide 23.

Inside the opening 22 of the upper drum 10 is a rotating fan mechanism 30 that also serves as a dynamic damper.
is fitted. This rotating fan mechanism 30 is constructed as shown in FIG. 3 in more detail.

In FIG. 3, an annular mounting bracket 3 is attached to a portion of the rotating shaft 17 that protrudes upward from the rotating drum 12.
1 is fitted and fixed. An annular elastic body 32 made of rubber, resin, or the like is interposed on the outer periphery of this fixture 31. This elastic body 32 has a vibration-proofing effect. A rotating body 33 is attached to the outer circumference of the fixture 31 via an elastic body 32. Rotating body 33
A plurality of blades 34 are provided along the circumferential direction on the circumferential surface of the...
are provided radially in the radial direction from the center. The blade 34 is inclined at a predetermined angle from the upper edge to the lower edge toward the front in the rotational direction of the rotating body 33, and is curved downward in the inclined direction into a slightly convex curved shape. This makes it possible to more effectively suck in air from around the drum and discharge it above the upper drum, which will be described later. The tips of the blades 34 extend to a position near the peripheral wall of the opening 22.

At the top of the top drum 10 is an air guide 35.
is attached to completely cover the upper part of the opening 22. One end of the air guide 35 is open, and the one end opening 36 is not shown.
It extends to the position of the VTR's heat sink. This air guide 35 efficiently guides and discharges the surrounding air sucked into the drum assembly by the suction action of the rotating fan mechanism 30 to the position of the heat radiation port.

Next, the operation of the drum assembly according to the present invention having the above structure will be explained.

First, the tape A is placed on the tape guide 2 on the circumferential surface of the drums 10 and 11 by the driving of the loading mechanism.
The tape is wound diagonally in a helical manner along the tape 3, and simultaneously loaded along a tape running system (not shown). Next, when recording, reproducing, etc., the tape running system is driven and the motor 21 is driven, the tape A runs along the circumferential surface of the drum in the direction of arrow 100, as shown in FIG. At the same time, the video heads 20, 20 are rotated along the slit 15 via the head disk 19 in the direction shown by arrow 101 due to the rotation of the rotating shaft 17. Due to this rotation, the video heads 20, 20 come into sliding contact with the tape A,
Recording, recording or playback is performed.

On the other hand, when the motor 21 is driven, the rotating body 33
rotates at high speed inside the opening 22 in the same direction as the video heads 20, 20, as shown by arrow 103. Then, the insides of the drums 10, 11 become under negative pressure with respect to the surrounding areas, and the air in the surrounding areas is sucked into the insides of the drums 10, 11 due to the suction action accompanying the rotation of the blades 34. That is, arrow 10 in FIG.
4, As shown in 105, the air in the peripheral area is covered with tape A.
and the peripheral surfaces of the drums 10, 11, and through the slits 15 formed between the two drums, into the drums 10, 11. The sucked air is discharged above the upper drum 10 through the opening 22 as the blades 34 rotate as shown by the arrow 106. This discharged air is guided by the air guide 35 to the position of the opening 36, and from there is discharged to the discharge port.

Then, when the surrounding air is sucked into the drum, the tape A is pulled into the drums 10 and 1 by the suction force.
It is suctioned into close contact with the circumferential surface of 1. Therefore, the tape A runs in optimal contact with the circumferential surface of the drum. In addition, phenomena such as flapping, vibration, and floating of the tape from the drum circumferential surface that occur when the video heads 20, 20 hit tape A are eliminated, and the contact between tape A and video heads 20, 20 is eliminated. It will be reliable and good.

Furthermore, the air sucked into the drum is passed through the blades 34...
Due to the rotational action of the upper drum 10, it is smoothly and quickly discharged outwardly, that is, in the upward discharge direction of the upper drum 10. Moreover, the air discharged above the upper drum 10 is efficiently and smoothly guided and discharged by the air guide 35 to the position of the heat radiation opening provided in the VTR. Therefore, heat dissipation efficiency can be improved, and a rise in temperature around and inside the drum assembly can be reliably prevented.

The rotor 33 is elastically supported by the elastic body 22, which has a vibration-proofing effect.
Therefore, since it also functions as a dynamic damper, the vibration of the head which has conventionally occurred when the head disk 19 rotates, that is, when the video heads 20, 20 rotate, is reliably damped and absorbed.

Moreover, the above-mentioned measures such as improving the contact between the tape and the video head, improving adhesion, improving heat dissipation efficiency, and reducing the vibration of the video head can all be achieved at the same time through a mechanism with a simple structure. can be achieved.

In the embodiment, the present invention was applied to a drum assembly consisting of an upper drum, a lower drum, and a rotating drum.
This invention is of course not limited to this, but can also be applied to a drum assembly in which a rotary drum integrally equipped with a video head is installed above a so-called lower drum.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the overall structure of the drum assembly according to the invention, Fig. 2 is a sectional view thereof, Fig. 3 is a perspective view of the main part of the drum assembly of the invention, and Fig. 4 is a perspective view of the drum assembly of the invention. It is a perspective view explaining operation. 10...Upper drum, 11...Lower drum, 15...Slit, 20, 20...Video head, 17...Rotating shaft, 30...Rotating fan mechanism, 31...Mounting bracket (fitting), 33...Rotation body, 32... elastic body (buffer), 34... feather,
35... Air guide, 36... Opening, 22...
An opening (provided in the top drum).

Claims (1)

[Scope of utility model registration request] In a drum assembly comprising a pair of upper and lower drums, and a video head rotatable along a slit formed between both drums, an elastic shock absorber is attached to a rotating shaft that supports the head. A rotary fan mechanism that also serves as a dynamic damper is formed by a substantially annular fitting fitted through the fitting and a rotating body having a plurality of blades on its circumferential surface, which is elastically supported by the rotating shaft via the fitting and the buffer. 1. A drum assembly for a magnetic recording and reproducing apparatus, characterized in that the rotating fan mechanism is disposed inside an upwardly opening opening formed in the upper drum.