JPH04229410A - Rotating type magnetic head drum - Google Patents

Abstract

PURPOSE:To prevent deviation in the rotating direction or the deviation of a rotating center from occurring between a rotor side core and a rotating yoke plate. CONSTITUTION:A notched part 511 is provided on the circumferential edge part of the lower end of the rotor side core 51. On the other hand, a pressing part 631 is provided on the circumferential edge part of the inside of the rotating yoke plate 63. When the yoke plate 63 is moved to the lower side of the core 51 and the projecting part 631 of the yoke plate 63 is engaged with the notched part 511 of the core 51, the yoke plate 63 and the core 51 are aligned. Simultaneously, the inside circumferential surface of the yoke plate 63 is brought into contact with the outside circumferential surface of the core 51 and the shaft center of the yoke plate 63 is aligned with the core 51.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating magnetic head drum installed in a magnetic recording/reproducing device such as a digital audio tape device or a video tape recorder.

0002

2. Description of the Related Art A conventional example of this type of rotating magnetic head drum is shown in FIG. The rotating magnetic head drum shown here includes a rotating upper drum 10 and a fixed lower drum 20 that are combined vertically, a motor 60 that drives the rotating upper drum 10, a magnetic head 40, and a magnetic head 4.
0 and the outside.

The rotating upper drum 10 is fixed to a shaft 30 rotatably supported at the axial center of the fixed lower drum 20. The magnetic head 40 is attached to the lower surface of the rotary upper drum 10, and by rotating together with the rotary upper drum 10, it scans the running tape at predetermined pitch intervals while being guided by the outer peripheral surface of the fixed lower drum 20.

The rotary transformer 50 has a cylindrical rotor-side core 51 and a cylindrical stator-side core 52 inserted into the rotor-side core 51. The rotor side core 51 is the sixth
In the structure shown in the figure, it is bonded to the inner circumferential surface of the rotating upper drum 10. Each motor 60 has an annular drive magnet 61, a drive coil component 62, and a rotating yoke plate 63. The drive magnet 61 is fitted onto the lower end of the rotor-side core 51 and is fixed to the rotating upper drum 10 with a screw 65 via a mounting boss 64 . Drive coil parts 62
is fixed to the fixed lower drum 20 in a state facing the lower surface of the drive magnet 61. The rotating yoke plate 63 is for concentrating the magnetic flux from the drive magnet 61.
It is disposed opposite to the drive coil component 62 and provided on the rotating upper drum 10 side.

[0005] Drive magnet 61, drive coil parts 62
, each gap of the rotating yoke plate 63 is set to about 0.2 to 0.3 mm in order to increase motor efficiency. In order to maintain the gap between the drive coil component 62 and the rotating yoke plate 63 at a desired value, the rotor-side core 51 and the rotating yoke plate 6
3, a cylindrical spacer 63 made of a non-magnetic material is interposed. The electromagnetic force from the drive magnet 61 acts on this rotating yoke plate 63, and this electromagnetic force is in the direction of pressing the rotating yoke plate 63 toward the spacer 63. As a result, the rotating yoke plate 63
3. It is fixed to the rotating upper drum 10 side via the rotor side core 51.

[0006]

[Problems to be Solved by the Invention] However, in the case of the above-mentioned conventional example, due to the structure, a shift in the rotation direction or a shift in the center of rotation is likely to occur between the rotor side core 51 and the rotating yoke plate 63. There are drawbacks. Moreover, all of these deviations become a factor that hinders the performance improvement of the drum. The present invention has been devised in view of the above circumstances, and its purpose is to provide a rotating magnetic head drum in which no deviation in the rotational direction or deviation of the center of rotation occurs between the rotor-side core and the rotating yoke plate. It is about providing.

[0007]

[Means for Solving the Problem] A rotating magnetic head drum according to claim 1 of the present invention has a magnetic head and holds a rotor-side core of a rotating transformer that transmits and receives signals between the magnetic head and the outside. A rotary magnetic head drum comprising an upper rotating drum, a fixed lower drum that is concentrically assembled below the upper rotating drum and holds a stator side core of a rotating transformer, and a motor that rotationally drives the upper rotating drum. By engaging the notch or notch provided on the inner peripheral edge of the rotary yoke plate of the motor with the notch or convex provided on the lower end peripheral edge of the side core, the rotor side core and this lower end The rotary yoke plate to be attached to the outer periphery is aligned.

In the rotary magnetic head drum according to a second aspect of the present invention, the rotary yoke plate is further axially aligned with the outer circumferential surface of the rotor-side core.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a rotating magnetic head drum according to the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a rotating magnetic head drum. The rotating magnetic head drum shown here includes a rotating upper drum 10 and a fixed lower drum 20 that are combined vertically, a motor 60 that drives the rotating upper drum 10, a magnetic head 40, and a signal exchange between the magnetic head 40 and the outside. It is equipped with a rotating transformer 50 that performs the following operations.

The rotating upper drum 10 is mounted concentrically on the upper part of the shaft 30. The shaft 30 has bearings 31 and 3 at the axial center position within the shaft portion 21 of the fixed lower drum 20.
It is rotatably supported at 1 and prevented from coming off by a stopper 32. A magnetic head 40 is attached to the lower surface of the rotating upper drum 10. A rotor-side core 51 of a rotary transformer 50 connected to the magnetic head 40 is fitted onto the inner surface of the upper rotating drum 10 and bonded to the inner peripheral surface with an adhesive or the like. The stator side core 52 inserted into the rotor side core 51 of the rotary transformer 50 is inserted into the fixed lower drum 2 with a predetermined gap between it and the rotor side core 51.
It is externally fitted onto the shaft portion 21 of 0. A tape guide surface is provided on the outer peripheral surface 22 of the fixed lower drum 20.

The motor 60 that drives the rotating upper drum 10 includes an annular drive magnet 61 and a drive coil component 6.
2. It is composed of a rotating yoke plate 63 and the like. The drive magnet 61 is fitted onto the lower end of the rotor-side core 51 and is fixed to the rotating upper drum 10 with a screw 65 via a mounting boss 64 . The drive coil component 62 is fixed to the fixed lower drum 20 while facing the lower surface of the drive magnet 61 . The rotating yoke plate 63 is made of a ferromagnetic material, and is fixed to the outer peripheral portion of the lower end of the rotor-side core 51 by the method described below. Note that the gaps between the rotor-side core 51, the drive magnet 61, and the rotating yoke plate 63 are set to about 0.2 to 0.5 mm.

FIG. 2 is a bottom view of the rotor-side core 51 seen from below, and FIG. 3 is a longitudinal cross-sectional view of the rotor-side core 51 taken along line AA in FIG. At the outer circumference of the lower end of the rotor side core 51,
As shown in the figure, a total of two groove-shaped notches 511 are provided so as to face each other. 4 is a plan view of the rotating yoke plate 63, and FIG. 5 is a sectional view of the rotating yoke plate 63. The rotating yoke plate 63 has a ring shape as shown in the figure, and its inner circumferential diameter is set to be approximately the same as the outer circumferential diameter of the rotor-side core 51. Further, on the inside of the rotating yoke plate 63, there is a convex portion 613 having a size corresponding to the notch portion 511.
A total of two are formed.

A rotating yoke plate 6 is provided below the rotor side core 51.
3 and cut out the notch 511 of the rotor side core 51.
When the convex portion 613 of the rotating yoke plate 63 is engaged with the rotating yoke plate 63, the rotating yoke plate 63 and the rotor-side core 51 are aligned. At the same time, the convex portion 6 on the rotating yoke plate 63
The inner circumferential surfaces other than 13 are in contact with the outer circumferential surface of the rotor-side core 51, and the rotary yoke plate 63 is aligned with the outer circumferential surface of the rotor-side core 51 as a reference. This rotating yoke plate 63
The electromagnetic force from the drive magnet 61 acts on the rotary yoke plate 63 , and this electromagnetic force is in a direction that presses the rotary yoke plate 63 against the rotor side core 51 .
is fixed to the outer peripheral portion of the lower end of the rotor-side core 51. However, instead of using this electromagnetic force, the rotating yoke plate 63 may be fixed to the rotor-side core 51 with an adhesive or the like.

It should be noted that the rotating magnetic head drum according to the present invention is not limited to the above-mentioned embodiments; for example, a convex portion may be provided on the rotor side core, and a notch may be provided on the upper surface of the rotating yoke plate. .

[0015]

As described above, in the case of the rotating magnetic head drum according to claim 1 of the present invention, the protrusions of the rotating yoke plate are engaged with the notches of the rotor-side core, and the rotating yoke plate is Since the rotor-side core is aligned with the rotor-side core, displacement of the rotating yoke plate in the rotational direction with respect to the rotor-side core is prevented. In the case of the rotating magnetic head drum according to claim 2 of the present invention, since the rotating yoke plate is axially aligned with respect to the outer peripheral surface of the rotor-side core,
Furthermore, displacement of the rotational yoke plate relative to the rotor-side core in the rotational direction is prevented. Therefore, it is of great significance in improving the performance of the rotating magnetic head drum.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a rotating magnetic head drum for explaining an embodiment of the present invention.

FIG. 2 is a bottom view of the rotor-side core of FIG. 1;

FIG. 3 is a longitudinal cross-sectional view of the rotor-side core taken along line AA in FIG. 2;

FIG. 4 is a plan view of the rotating yoke plate of FIG. 1;

FIG. 5 is a cross-sectional view of the rotating yoke plate of FIG. 1;

FIG. 6 is a diagram corresponding to FIG. 1 for explaining a conventional rotating magnetic head drum.

[Explanation of symbols]

10 Rotating upper drum 20 Fixed lower drum 40 Magnetic head 50 Rotating transformer 51 Rotor side core 52 Stator side core 511 Notch part 60 Motor 63 Rotating yoke plate 631 Convex part

Claims (2)

[Claims] 1. A rotary upper drum that holds a rotor-side core of a rotary transformer having a magnetic head and transmitting and receiving signals between the magnetic head and the outside; and a rotary upper drum that is concentrically combined below the rotary upper drum; In a rotating magnetic head drum that includes a fixed lower drum that holds a stator-side core of a rotating transformer and a motor that rotationally drives a rotating upper drum, a notch or a convex portion provided at the lower end peripheral portion of the rotor-side core has a The rotor-side core and the rotary yoke plate to be attached to the lower end outer circumference of the motor are aligned by engaging a convex portion or notch provided on the inner peripheral edge of the rotary yoke plate of the motor. Rotating magnetic head drum. 2. The rotating magnetic head drum according to claim 1, wherein the rotating yoke plate is axially aligned with respect to the outer peripheral surface of the rotor-side core.