JPH0118486B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tape guide drum for recording and reproducing video signals in a rotating magnetic head type magnetic recording and reproducing apparatus (hereinafter referred to as a VTR).

As is well known, in VTRs that use a rotating magnetic head, a non-contact rotary transformer is used to send and receive signals between the rotating part and the fixed part. Opposite types are often used. This rotary transformer has a rotating part that is connected to the rotating magnetic head and rotates integrally with it, and a fixed part that is attached to the fixed side of the bearing or tape guide, which face each other in the plane direction, and are capable of transmitting signals. is configured to do so. In terms of function and performance, this planar facing type rotary transformer is required to have a constant distance between the rotary transformers in the rotating part and the fixed part, and to minimize surface runout. Therefore, various mounting structures have been proposed to meet these demands.

FIG. 1 shows an embodiment of a conventional device.

The rotating part rotary transformer 18 is glued to the rotating disk 16, and a spacer with the same thickness as the desired distance g is sandwiched between it and the fixed part rotary transformer 20, and then the rotating disk 16 is fixed to the main shaft 14 with screws 12. to obtain the desired spacing.

Further, in the embodiment of another conventional device shown in FIG.
The main shaft 3 is attached to the rotary disk 34.
2 is fitted and fixed. The main shaft 32, rotating disk 34, rotary transformer 36, bearings 50a, 50b, spacer 48, and preload boss 46 are integrally slidable in the bearing insertion hole 44 of the fixed drum 42, and are rotated by sliding. A spacer having the same thickness as the desired spacing g is sandwiched between both the rotary transformers of the section and the fixed section, and the spacer 48 is fixed to the fixed drum 42 with screws 40 to obtain the desired spacing between the two rotary transformers. Ta.

However, in both the embodiments shown in FIG. 1 and FIG.
Since there are variations in dimensions in the thickness direction of single items of 0 and 38, the height H' from the reference plane B to the mounting surface A of the rotating drums 17 and 35 of the rotating disks 16 and 34 varies, and therefore the rotating magnetic head 10 , 30, the height H from the reference plane B was not within the set range in many cases. Therefore, after adjusting the distance between the rotary transformers on both the rotating and fixed sides,
by assembling or doing something similar.
The height H from the rotary magnetic head 10, 30 to the rotary magnetic head 10, 30 must be set to a predetermined value, which requires an extremely large amount of time.

The present invention is capable of solving the drawbacks of such conventional devices, and aims to provide a tape guide drum device that can easily and reliably set the distance between the rotating part and the fixed part of a rotary transformer to a desired value. It is.

The configuration of the present invention will be described in detail below based on embodiments shown in the drawings, but the technical scope of the present invention is not limited to these embodiments.

FIG. 3 is a longitudinal cross-sectional view of the device according to the invention, in which the tape guide 60 includes a cylindrical rotating drum 74 and a stationary drum 84. The rotary drum 74 has a built-in rotary magnetic head 62 and rotates together with it. A video signal is recorded on tape 86 or played back from it.

The rotary drum 74 is fixed to a rotary disk 70 into which a main shaft 68 is fitted and fixed with a required number of screws 66, and rotates together with the main shaft 68. Note that the rotating drum 7
Dimensions from the magnetic head mounting surface of No. 4 to the mounting surface A of the rotating disk 70, dimensions from the mounting surface A of the rotating drum 74 of the rotating disk 70 to the surface C in contact with the upper bearing 104a, the upper bearing 104a
Since the width dimension of the fixed drum 84 and the dimension from the surface D supporting the outer ring of the upper bearing 104a of the fixed drum 84 to the reference plane B can be determined very accurately with a single item, the height H from the reference plane B to the rotating magnetic head. are precisely set to predetermined dimensions.

The fixed drum 84 has a stepped portion on its outer periphery for winding and guiding the magnetic tape 86 in an oblique direction.
In the embodiment shown in FIG. 3, the bearing portion that rotatably supports the main shaft 68 has a shape that is integrated with the fixed drum 84, but the present invention is not limited to such a structure; It is also possible to separate them and connect them with screws or the like.

The bearing section 100 consists of a housing 102 and two bearings 104a, 104b. These two bearings 104a, 104b are screwed to the lower end surface of a rotary disk 70 that is integral with the main shaft 68 and the main shaft 68, and are attached to plate springs. 108 and receiving plate 10
6 and a preload boss 110 pressing the bearing 104b, a preload is applied in a direction such that the inner rings thereof tend to approach each other in the axial direction.

The rotary transformer for transmitting and receiving signals to and from the rotating magnetic head 62 is of a plane facing type, in which a flat rotating part 78 and a fixed part 80 face each other in a plane perpendicular to the main axis. There is. The rotating part 78 of the rotary transformer is bonded to a rotary transformer adjusting member 64, and this rotary transformer adjusting member 64 has a built-in leaf spring 76 and is slidably fitted to the rotary disk 70. When completed, it is fixed to the rotary disk 70 from the radial direction by screws 72 and rotates integrally with the rotary disk 70. The leaf spring 76 presses the rotary transformer adjusting member 64 in the direction of the main axis. Fixed part 80 of rotary transformer
is a screw (not shown) on one end surface of the fixed drum 84 side.
The rotary transformer rotating portion 78 is fixed to the rotary transformer rotating portion 78 and faces the rotary transformer rotating portion 78 . The rotary transformer rotating part 78 and the rotary transformer fixing part 80 have an interval determined by an assembly method described later.

Further, a plurality of holes 90 are formed in the circumference of the fixed drum 84 to be used during assembly, and a gap g between the rotating part 78 and the fixed part 80 of the rotary transformer is formed.
It is configured such that a spacer 82 can be inserted for setting the .

Signals are taken out from the rotary transformer fixing section 80 through a terminal 88 connected to the wound coil.

The structure of one embodiment of the device according to the present invention has been described above, but in order to make it easier to understand the effects of the present invention, the distance between the rotating part 78 and the fixed part 80 of the rotary transformer in the main axis direction is A method of assembling to obtain the desired value will be explained.

The rotary transformer adjusting member 64 is temporarily fixed to the rotary disk 70 with screws 72 so that the distance between the rotating part 78 and the fixed part 80 of the rotary transformer is larger than a desired value.

A plurality of holes 90 are provided on the outer periphery of the fixed drum 84 with spacers 82 having the same thickness as the desired spacing g.
Insert the rotary transformer rotating part 78
and the fixing part 80, loosen the temporarily fastened screw 72, and the spacer 82 is placed between the opposing surfaces of the rotating part 78 and the fixing part 80 of the rotary transformer by the axial pressing force of the plate spring 76. By holding it in place and fully tightening the screw 72 in this state, and then removing the spacer 82, the desired spacing can be obtained.

FIG. 4 shows a longitudinal sectional view of another embodiment of the device according to the invention. The rotary transformer rotating part 132 is attached to the rotary transformer adjusting member 130, and the rotary transformer adjusting member 130
is slidably fitted to the main shaft 126, and by sliding it, the rotating part 132 of the rotary transformer
A spacer 136 having the same thickness as the desired distance g is sandwiched between the fixed part 134 and the rotary transformer adjusting member 130 with the screw 128.
A desired spacing can be obtained by fixing it to .

In addition, the dimensions from the rotating magnetic head mounting surface of the rotating drum 122 to the rotating disk 124 mounting surface A,
The dimension from the surface C of the rotating disk 124 in contact with the upper end surface of the main shaft 126 to the mounting surface A of the rotating drum 122, the dimension from the surface C of the rotating disk 124 in contact with the upper end surface of the main shaft 126 to the surface D where the stopper 138 contacts the upper bearing 140a, Width dimension of upper bearing 140a and fixed drum 14
Since the dimension from the surface E supporting the outer ring of the upper bearing 140a of 2 to the reference surface B can be controlled with high precision before assembly, the height H from the reference surface B to the rotating magnetic head 120 can be adjusted to a predetermined dimension. Can be set accurately.

As described above, the tape guide drum device according to the present invention is provided with an adjusting member that is slidable in the axial direction using the rotating disk or main shaft as a guide, which is separate from the rotating drum to which the magnetic head is attached. Now that the rotating side rotary transformer is installed, insert a spacer through the hole between the fixed side and rotating side rotary transformers, and then move this adjustment member in the axial direction to adjust the height of the rotating magnetic head from the reference plane. The gap between the fixed and rotating rotary transformers can be set to the desired value very easily and accurately without affecting the There is no need for any troublesome and time-consuming assembly work, and productivity is extremely high. Alternatively, since the adjustment member is fixed to the rotating disk, the rotating drum can be replaced without causing the rotary transformer to vibrate due to unbalance of the rotating body, and without affecting the spacing between the rotary transformers. It also has the following effects.

[Brief explanation of drawings]

Figures 1 and 2 are longitudinal sectional views of the conventional device;
4 and 4 are longitudinal sectional views each showing an embodiment of the device according to the present invention. 62,120...Rotating magnetic head, 64,13
0...Rotary transformer adjustment member, 68, 12
6... Main shaft, 70, 124... Rotating disk, 7
4,122...Rotating drum, 78,132...Rotary transformer rotating part, 80,134...Rotary transformer fixing part, 82,136...Spacer, 84,142...Fixed drum, 86...Magnetic tape, 76 ...Flat spring.

Claims (1)

[Claims] 1. A rotating drum with a built-in rotating magnetic head, a fixed drum whose outer periphery can be wrapped with tape to guide its travel, a rotating disk to which the rotating drum is attached, and a main shaft that is fitted and fixed to the rotating disk and rotatably supports it. a bearing part, and a rotating part and a fixed part which are disposed on the rotating drum side and the fixed drum side and facing each other in a plane perpendicular to the main axis in order to send and receive signals to the rotating magnetic head. A tape guide drum device comprising a pair of rotary transformers, wherein an adjustment member is provided integrally with the rotary transformer and is slidable in the axial direction using the rotary disk or the main shaft as a guide, A plurality of holes are formed in the circumference of the drum into which spacers can be inserted between the pair of rotary transformers, and a desired distance is created between the pair of rotary transformers through the spacers inserted between the pair of rotary transformers. A tape guide drum device characterized in that the adjusting member is fixed to the rotary disk or the main shaft after the adjustment member is fixed to the rotary disk or the main shaft.