JPH0442418A - Rotary drum structure for rotary magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To attain miniaturization by providing a motor which drives an upper rotary drum in a drum, and fixing the rotor of a rotary transformer on the upper rotary drum by the attractive force of a driving magnet. CONSTITUTION:The motor 60 which drives the upper rotary drum 10 is assembled in a lower fixed drum 20, and it is equipped with a ring driving magnet 61 assembled concentrically, a driving coil assembly 62, and a rotary yoke 66. Torque is generated between the driving magnet 61 and the driving coil assembly 62 by permitting a current to flow on the driving coil assembly 62, which rotates the upper rotary drum 10. Simultaneously, the rotary yoke 66 consisting of a magnetic material is attracted on the driving magnet 61, and the attractive force is added on the rotor 51 as a pushing up force. Consequently, the rotor 51 can be fixed on the upper rotary drum 10 regardless that it is not fixed mechanically. Thereby, no mechanical fixing means is required, and also, the motor 60 can be incorporated, and the structure of a rotary drum can be miniaturized.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a rotating drum structure used in a rotating magnetic recording/reproducing device such as a consumer video tape recorder or a digital audio tape recorder.

<Prior Art> As a conventional structure of this type, there is a rotating drum structure shown in FIG. This rotating drum structure includes a rotating upper drum 71 and a fixed lower drum 72 that are vertically combined concentrically, a magnetic head 73 in a rotating magnetic recording/reproducing device, and a rotary transformer 74 used for signal transmission.

The rotating upper drum 71 is fixed to a shaft 75 rotatably supported at the axial center of the fixed lower drum 72, and the shaft 75 is driven by a motor 76 attached to the lower surface of the fixed lower drum 72. Rotates due to

The magnetic head 73 is attached to the lower surface of the rotating upper drum 71, and by rotating together with the rotating upper drum 71, scans the running tape guided by the outer peripheral surface of the fixed lower drum 72 at a predetermined pitch.

The rotary transformer 74 has a cylindrical rotor R and a cylindrical stator S inserted into the rotor R. The rotor R is positioned on the inner circumferential surface of the upper rotating drum 71 and needs to be removed when replacing the magnetic head 73. It is fixed at 71. A stator S of the rotary transformer 74 is fixed to the fixed lower drum 72.

<Problems to be Solved by the Invention> In such a conventional rotating drum structure, in order to make the rotor R of the rotary transformer 74 detachable from the upper rotating drum 71, the presser metal fitting 77 and its set screw 78 are used.
is used. This hinders miniaturization and also makes it difficult to replace the rotor R.

The present invention was devised in view of the above circumstances, and its purpose is to enable the rotor of a rotary transformer to be freely attached to and detached from the rotating upper drum, and to make the process easy and compact. The purpose is to provide a rotating drum structure.

Means for Solving the Problems> A rotating drum structure according to the present invention includes a magnetic head in a rotating magnetic recording and reproducing device, and a rotating upper drum that holds a rotor of a rotary transformer used for signal transmission; The rotary transformer is concentrically assembled below the upper drum, and has a tape guide surface on its outer peripheral surface, a fixed lower drum that holds the stator of the rotary transformer, and a motor that drives the rotating upper drum. The motor is characterized in that it is provided within the drum so that the rotor of the rotary transformer is fixed to the rotating upper drum by the attraction force of the drive magnet.

<Function> A motor that drives the rotating upper drum is provided inside the drum, and the rotor of the rotary transformer is fixed to the rotating upper drum by the attraction force of the driving magnet. No need for screws or set screws.

<Example> Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view showing an example of a rotating drum structure according to the present invention.

The rotating upper drum 10 is assembled concentrically on the fixed lower drum 20. The shaft 30 supporting the 0-rotating upper drum 10 is rotatably mounted within the shaft portion 21 of the fixed lower drum 20 by a bearing 31.31. supported and stopper 32
Extraction is stopped.

A magnetic head 40 is attached to the lower surface of the rotating upper drum 10. A rotor 51 of a rotary transformer 50 connected to the magnetic head 40 is inserted into the upper rotating drum 10 and positioned on the inner peripheral surface of the upper rotating drum 10 . The stator 52 inserted into the rotor 51 of the rotary transformer 50 is inserted into the shaft portion 21 of the fixed lower drum 20 with a predetermined gap between the stator 52 and the rotor 51.
is fitted externally. A tape guide surface is provided on the outer peripheral surface of the peripheral wall portion 22 of the fixed lower drum 20.

Note that the structures of the rotating upper drum 10 and the fixed lower drum 20 are not much different from those structures used in conventional rotating drum structures.

The motor 60 that drives the rotating upper drum IO is built into the lower fixed drum 20 and includes an annular driving magnet 61, a driving coil assembly 62, and a rotating yoke 66 that are concentrically assembled.

The drive magnet 61 is positioned on the outer peripheral surface of the lower end of the rotor 51, and is attached to the rotating upper drum 10 by a set screw 63.
Fixed. 64 and 65 are drive magnets 61
It is a holding and fixing member. The drive coil assembly 62 is fixed to the inner peripheral surface of the peripheral wall of the fixed lower drum 20 and faces the drive magnet 61 with a gap below. This drive coil assembly 62 has a 0-rotation yoke 66 that does not receive the magnetic force from the drive magnet 61, and is made of a magnetic material to concentrate the magnetic flux from the drive magnet 61. It is placed in a non-contact manner in a gap provided in the The rotating yoke 66 is connected to the lower end surface of the rotor 51 via a spacer 67.

In the rotating drum structure having the above configuration, the drive coil assembly 6
2, the drive magnet 61
A rotational force is generated between the drive coil assembly 62 and the drive coil assembly 62, causing the rotating upper drum 10 to rotate. At this time, drive coil assembly 6
2, the magnetic flux from the drive magnet 61 is concentrated on the drive coil assembly 62, improving the efficiency of the motor 60.

At the same time, the rotating yoke 66 made of magnetic material is attracted to the drive magnet 61. This suction force is applied to the rotor 51 via the spacer 67 as a pushing force. As a result, the rotor 51 is fixed to the rotating upper drum IO even though it is not mechanically fixed. Therefore, mechanical fixing means such as presser metal fittings and their setscrews are not required, and together with the fact that the motor 60 is built into the drum, the rotating drum structure can be significantly downsized.

Further, in each of the assembly and disassembly operations, there is no need for screwing or the like for fixing the rotor 51, so that the number of man-hours is reduced and the efficiency of the operation is improved.

<Effects of the Invention> As described above, in the case of the rotating drum structure according to the present invention,
Since there is no need for a member to fix the rotor of the rotary transformer to the rotating upper drum, it can be made smaller, and the number of parts can be reduced, reducing manufacturing costs. It also becomes possible to reduce man-hours.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of a rotating drum structure according to the present invention, and FIG. 2 is a sectional view showing a conventional rotating drum structure. 10, 20, 40, 50, 51, 52... Rotating upper drum... Fixed lower drum... Magnetic head... Rotary transformer... Rotor... Stator 60, 61, 62, 66... Motor drive magnet drive coil set rotating yoke

Claims (1)

[Claims] (1) A rotating upper drum that is equipped with a magnetic head in a rotating magnetic recording and reproducing device and holds the rotor of a rotary transformer used for signal transmission; The rotary transformer is provided with a tape guide surface, a fixed lower drum that holds the stator of the rotary transformer, and a motor that drives the rotary upper drum. A rotating drum structure for a rotating magnetic recording/reproducing device, characterized in that the rotor is provided within the drum to fix the rotor to the upper rotating drum.