JPH04121810A - Drum unit - Google Patents

Abstract

PURPOSE:To eliminate the influence of the working accuracy and assembling accuracy of an upper drum on the rotating locus of a magnetic head and to improve assembling workability by mounting the magnetic head on a sheet of flange plate with a step mounted integrally on a rotary shaft. CONSTITUTION:The flange plate 12 with a step on which a rotating side rotary transformer 11a is fixed is fitted in the shaft 13a set rotatably freely of a shaft integral type bearing 13 with sleeve fitted in a lower drum 5, and plural magnetic heads 2 are mounted on the magnetic head mounting plane 121b of the flange plate 12 with a step whose finish working is performed setting the shaft integral type bearing 13a with a sleeve as reference, and similarly, the upper drum 1 is mounted on an upper drum mounting planes 122b whose finish working is performed setting the shaft 13a as reference and a unpper drum fitting part 123b, and the height adjustment of the plural magnetic heads 2 can be performed with a step adjusting screw 17 provided at the upper drum 1.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a drum unit of a rotary head type magnetic recording/reproducing device such as a VTR or DAT, and particularly relates to mounting of a magnetic head and a rotating side rotary transformer. .

[Prior art 1] For example, Utility Model Application No. 64-801 and Utility Model Application No. 64-245
The structure of the conventional drum unit shown in Japanese Patent No. 08 will be explained.

FIG. 17 is a perspective view showing the appearance of a conventional drum unit;
FIG. 18 is a sectional view of a conventional drum unit, and FIG. 19 is a plan view showing how a magnetic head is attached to the conventional upper drum.

In the figure, (1) is the upper drum which is a rotating part, (2) is a magnetic head that sends and receives signals to and from a tape-shaped magnetic recording medium (magnetic tape), (2a) is a magnetic helad tip, (2b) is ) is the head base to which the magnetic head chip (2a) is attached, (3) is the magnetic head (2) attached to the upper drum (
1), (4) is a notch called a window provided in the upper tram (1), (5) is a fixed lower drum, (5a) is provided on the outer circumferential surface of the lower drum (5). (6) is a drive motor that rotates the upper drum (1); (7) is a chassis (not shown) to which the drum unit is attached; (8) is a bearing that supports the rotation axis of the upper drum (1), (9) is the shaft that is the rotation axis of the upper drum (1), (10) is the upper drum (
Shaft (9) which is the mating member when attaching 1)
(lla) is a rotating side rotary transformer fixed to the flange (10), and (llb) is a fixed side rotary transformer fixed to the lower drum (5).

Next, the operation will be explained. In a typical drum unit assembly process, the bearing (8) is first fixed to the lower drum (5) by a method such as press fitting, and the fixed rotary transformer (llb) is adhered to the lower drum (5). After the rotating side rotary transformer (lla) is bonded to the flange (10) integrated with the shaft (9), the bearing (
A shaft (9) is fixed to the inner ring of (8). On the other hand, the magnetic head (-2) is finely adjusted so that it protrudes a certain distance from the outer peripheral surface of the upper drum (1), and its posture is adjusted so that the head gap at the tip of the magnetic head (2) is at the top. is then fixed to the upper drum (1) via screws (3). Each of the above adjustments requires precision on the order of microns. Then, the upper drum (1) to which the magnetic head (2) is attached is fixed to the flange (10).

In addition, since the magnetic herad chip (2a) and the rotating side rotary transformer (lla) are attached to separate members, the signal line (not shown) is usually relayed on the top surface of the upper drum (1). [Problem to be solved by the invention] Since the conventional tram unit is configured as described above, even if the magnetic head (2) is attached to the upper drum (1) with high precision, the flange (10 ), if the mounting accuracy of the upper drum (1) is poor, or if the machining precision of the upper drum itself such as eccentricity or the machining precision of the surface of the upper drum mounting is poor, the magnetic head (2) may There was a problem in that the desired accuracy could not be obtained in the rotation locus. In addition, the magnetic head (
2) and the rotating side rotary transformer (lla) must be routed after the drum unit is assembled, posing the problem of complicating the process.

This invention was made to solve the above-mentioned problems, and provides a rotating head that can obtain a high-precision magnetic head rotation trajectory with small cumulative errors in processing and assembly, and that also simplifies the assembly process. The purpose of this invention is to obtain a drum unit for a type magnetic recording/reproducing device.

[Means for Solving the Problems] A drum unit according to the present invention has a magnetic head and a rotary transformer on the rotating side attached to a single stepped flange plate that is integrally attached to a rotating shaft, and The upper drum is attached to it.

[Function] In the drum unit of the present invention, the magnetic head is mounted on a single stepped flange plate that is mounted integrally with the rotating shaft, so the rotation locus of the magnetic head depends on the machining accuracy and assembly accuracy of the upper drum. Not affected. Furthermore, since the magnetic head and the rotating side rotary transformer are mounted on a single stepped flange plate, assembly work efficiency is improved.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 7. Fig. 1 is a cross-sectional view of a drum unit showing an embodiment of the present invention, Fig. 2 is a cross-sectional view of a component in which a rotary transformer is attached to a stepped flange plate, and Fig. 3 is a lower drum with an integrated shaft with a sleeve. Figure 4 is a cross-sectional view of the fixed-side rotary transformer with the bearing fitted, and Figure 4 is a cross-sectional view of the parts shown in Figures 2 and 3 fitted together. Figure 5 is the same as Figure 4. Figure 6 is a cross-sectional view of the magnetic head attached to the shown component, Figure 6 is a plan view of Figure 5 viewed from the direction in which the magnetic head is attached, Figure 7 is an enlarged view of the head gap to explain the height difference adjustment of the magnetic head. It is a diagram.

In the figure, (5b) is the sleeve fitting hole provided in the lower drum (5), (5c) is the fixed side rotary transformer adhesive surface of the lower drum (5), (12) is the stepped flange plate,
(12a) is a shaft fitting hole provided in the stepped flange plate (12), (12b) is the stepped flange plate (12)
Holes for signal lines provided in (121a), (121b
) is the magnetic head mounting surface, (122a), (122b
) is the upper drum mounting surface, (123a), (12
3b) is the upper drum fitting part, (124) is the adhesive surface of the rotating side rotary transformer, (13) is the stepped flange plate (12)
This is an integrated bearing with a shaft with a sleeve that rotatably supports the (1
3a) is the shaft, (13b) is the steel ball, (13c) is the outer ring, (13d) is the sleeve that constitutes the outer peripheral surface of the bearing, (
14) is the relay board (15) is the rotating side rotary transformer (lla) and the relay board (14) through the hole (12b)
(16) is the screw that attaches the upper drum (1) to the stepped flange plate (12), (17) is the step adjustment screw that adjusts the height of the magnetic head, (18) is the lower drum ( 5) to the drum base (7), (
19) is a signal line connecting the relay board (14) and the magnetic l\rad 2), (20) is the head gap, (21) is the movable direction of the magnetic head (2), and Ll is the rotating side rotary transformer (11a). and the fixed side rotary transformer (llb), and L2 is the head step representing the deviation of the lower end of the head gap (2o) of the plurality of magnetic heads (2).

Note that (121a), (122a), and (123a) represent the states of the stepped flange plate (12) before finishing the respective surfaces with reference to the shaft (13a);
b), (122b), and (123b) represent after finishing processing. Further, the same or corresponding parts as those of the conventional device described above are given the same reference numerals, and the description thereof will be omitted.

Next, the operation will be explained.

Figure 1 shows the entire drum unit after assembly is completed, and in the figure, the rotatable shaft (13a
) is fitted with a stepped flange plate (12) to which the rotating side rotary transformer (lla) is fixed. 12) Magnetic head mounting has a plurality of magnetic heads (2) attached to the surface (121b), and the upper drum mounting, which is also finished based on the shaft (13a), is mounted on the surface (122b) and the upper drum fitting. Part (1
An upper drum (1) is attached to the upper drum (1), and the head height (step) of the plurality of magnetic heads (2) is adjusted by a step adjustment screw (17) provided on the upper drum (1).

The individual assembly steps will be explained according to FIGS. 2 to 7.

In FIG. 2, the rotating side rotary transformer (lla) is fixed to the rotating side rotary transformer adhesive surface (124) with reference to the shaft fitting hole (12a). Pass the signal wire (15) from the rotating side rotary transformer (11a) through the hole (12b) of the stepped flange plate (12), and connect the relay board (14) pasted on the stepped flange plate (12).
).

In Fig. 3, the integral shaft bearing with sleeve (13) is
It is fixed to the sleeve fitting hole (5b) of the lower drum (5) by press fitting, shrink fitting, or adhesive. The fixed rotary transformer (llb) is fixed to the fixed rotary transformer adhesive surface (5c) of the lower drum (5).

In FIG. 4, the parts shown in FIG. 3 and the parts shown in FIG.
), there is a set distance L1 between the rotating side rotary transformer (lla) and the stationary side rotary transformer (11b).
They are fitted and fixed by press-fitting, shrink-fitting, gluing, or screwing so that Next, with the shaft (13a) as a reference, finish processing is performed on the surface (121a) for the magnetic head attachment of the stepped flange plate (12), the surface (122a) for the upper drum attachment, and the upper drum fitting part (123a). to bring each surface within a predetermined accuracy based on the shaft (13a). After finishing, each surface has a magnetic head mounting surface (1
21b), the upper drum is attached to the surface (122b), and the upper drum fitting part (123b).

In FIGS. 5 and 6, the finished magnetic head mounting is performed by placing a plurality of magnetic heads (2) on the surface (121b) by the amount of protrusion, the mounting by the posture, and the mounting by the angle (
Glue and fix while adjusting with a jig so that the indexing) has the specified accuracy. Next, the relay board (14) and the magnetic head (
2) through a signal line (19) to complete the connection between the rotating side rotary transformer (lla) and the magnetic head chip (2a).

After that, as shown in Figure 1, the stepped flange plate (12
) The upper tram is fixed to the surface (122b) with a plurality of screws (16) via the upper drum fitting part (123b). At this time, the upper drum (1) is positioned in the radial direction by fitting with the upper drum fitting part (123b), and the upper drum fitting part (123b) is connected to the shaft (1).
3a) The shaft (1
The coaxiality of the upper drum (1) with respect to 3a) is maintained.

Next, as shown in FIG. 7, by pushing and pulling the head base (2b) in the movable direction (21) using the step adjustment screw (17), the lower end of the head gap (20) of the plurality of magnetic heads (2) is The head height difference L2 is adjusted to within a predetermined accuracy.

In addition, in the above embodiment, the sleeve-integrated shaft bearing (13)
After fitting to the lower drum (5), attach the stepped flange plate (1) to the lower drum (5).
2) was fitted onto the shaft (13a), but as shown in FIG.
), attach the parts shown in Figure 8 to the lower drum (5).
It may be fitted to

Further, in the above embodiment, a square helad base (2b) was used as shown in FIG. 6, but as shown in FIG.
A bow-shaped (arc-shaped) head base (2b) may also be used.

Further, in the above embodiment, an arc-shaped stepped flange plate (12) is shown as the stepped plate, but as shown in FIG. 10, a rectangular stepped flange plate (12) may also be used. 2), the rotating side rotary transformer (11a) and the upper drum (1) can be attached, and the shaft (1)
If it has a shape that can be fitted and fixed to 3a), the same effects as in the above embodiment can be achieved.

Further, in the above embodiment, the magnetic head (2) is fixed to the stepped flange plate (12) by adhesive, but it may also be fixed using screws (22) as shown in FIG.

Further, in the above embodiment, the radial positioning of the upper drum (1) and the stepped flange plate (12) is performed at the upper drum fitting portion (1).
23b), but the shaft (13a) may be used as shown in FIG.

In addition, in the above embodiment, a jig (not shown) was used to position the stepped flange plate (12) and the rotating side rotary transformer (lla), but as shown in FIG. A side rotary transformer positioning surface (125) may be provided on the stepped flange plate (12).

In addition, in the above embodiment, the head level difference was adjusted using the level difference adjustment screw (17) in the drum unit state, but if high precision adhesion, high precision finishing processing, and high precision assembly of the magnetic head (2) can be performed, As shown in FIG. 14, the step adjustment screw (17) may be omitted.

In addition, in the above embodiment, the shaft integrated bearing with sleeve (13)
However, as shown in FIG. 15, a shaft-integrated bearing (130) without a sleeve may also be used. Ordinary ball bearings may also be used, as shown in FIG. 16.

[Effect of the invention 1 As described above, according to the present invention, the magnetic head is attached to the stepped flange plate after finishing is applied to one stepped flange plate fixed to the rotating shaft. Therefore, there is an effect that a highly accurate magnetic head rotation locus can be realized. In addition, since the magnetic head and rotating side rotary transformer are fixed to two stepped flange plates,
Signal lines can be routed before attaching the upper drum, improving assembly work efficiency and reducing work time. Further, since the upper drum has a simplified shape and can reduce the required precision, it becomes easier to process and can be replaced with a molded product, making it possible to significantly reduce the cost.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a drum unit showing an embodiment of the present invention, Fig. 2 is a cross-sectional view of a component in which a rotary transformer is attached to a stepped flange plate, and Fig. 3 is a lower drum with an integrated shaft with a sleeve. Figure 4 is a cross-sectional view of the parts in which the bearings are fitted and the fixed side rotary transformer is attached. Figure 4 is a cross-sectional view of the parts in which the parts shown in Figures 2 and 3 are fitted together. Sectional view of the magnetic head attached to the shown parts, No. 6
The figures are Fig. 5, a plan view of the mounting direction of the magnetic head, Fig. 7 is an enlarged view of the head gap section to explain the step adjustment of the magnetic head, and Fig. 8 is Fig. 2 showing another assembly example. The sectional view to be compared, FIG. 9, is the sixth sectional view showing another embodiment.
FIG. 10 is a plan view to be compared with FIG. 6 showing another embodiment, and FIG. 11 is a plan view to be compared with FIG. 1 showing still another embodiment. Cross section, 1st
2 is a sectional view to be compared with FIG. 1 showing still another embodiment, FIG. 13 is a sectional view to be compared with FIG. 1 showing still another embodiment, and FIG. 14 is a sectional view to be compared with FIG. 1 showing still another embodiment. First example
15 is a sectional view to be compared with FIG. 1 showing another embodiment, and FIG. 16 is a sectional view to be compared with FIG. 1 showing still another embodiment. Cross section, 1st
Figure 7 is a perspective view showing the appearance of a conventional drum unit.
FIG. 8 is a sectional view of a conventional drum unit, and FIG. 19 is a plan view showing how a magnetic head is attached to the conventional upper drum unit. In the figure, (1) is the upper drum, (2) is the magnetic head,
(lla) is a rotating side rotary transformer, (12) is a stepped flange plate, (13) is a shaft integrated bearing with sleeve, (
13a) is a shaft, (14) is a relay board, (15) is a signal line, and (17) is a step adjustment screw. In addition, the same symbols in the figures indicate the same or equivalent parts. Agent Patent Attorney Masu Oiwa Figure 19 Credit delivery fee Figure Figure 14 Figure a

Claims (1)

[Scope of Claims] 1. A drum unit equipped with a magnetic head of a rotary head type magnetic recording/reproducing device configured to form diagonal signal tracks on a tape-shaped magnetic recording medium,
A fixed lower drum, a rotating shaft rotatably attached to the lower drum, a flange integrally attached to the rotating shaft, a rotating upper drum fixed to the upper part of the flange, and a rotating means for rotating the rotating shaft. and a drum unit consisting of a rotary transformer on a rotating side and a rotary transformer on a stationary side, which are provided so as to face a lower part of the flange and the lower drum in order to send and receive signals to and from the magnetic head, the flange being disposed on the intermediate side. a stepped flange plate to which a magnetic head can be directly attached at a position, and before attaching the upper drum to the upper part of the stepped flange plate, the magnetic head is attached to the stepped flange plate; A drum unit characterized in that a lower rotating side rotary transformer and the magnetic head are electrically connected.