JP2642815B2 - Method of assembling head drum of magnetic recording / reproducing apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a VTR (video tape recorder) and a DAT (digital audio tape recorder).
And a method of assembling a head drum for magnetic recording and reproduction.

[0002]

2. Description of the Related Art In such a head drum, in order to efficiently transmit an electric signal, as shown in FIG. 5, between a fixed rotary transformer (9) and a rotary rotary transformer (8). in the gap G ₀ a predetermined range, for example 40
It is necessary to assemble so as to fit within ６０60 μm.

As one of the methods, as shown in FIG. 5, a flywheel having a rotary rotary transformer (8) fixed thereto.
Spacer between the bearing contact surface (31) of (3) and the bearing (5)
(6) is inserted, and the influence of the thickness variation of the rotary transformers (8) and (9), the thickness error of the bearing (5) and the processing error of the fixed cylinder (2) is caused between the rotary transformers (8) and (9). and in the manner it does not appear to variations in the gap G _0.

When the compatibility of the head drum is taken into consideration, the magnetic head is moved from the lower reference surface (21) of the fixed cylinder (2).
The error of the height H ₀ up to (7) is within a certain range, for example, 50 μm.
It is necessary to make the following so that the outer peripheral tape sliding contact surface (11) of the rotary cylinder (1) is concentric with the rotary shaft (4).

[0005] Therefore, the rotary cylinder flywheel and (3) after assembly by setting the gap G ₀ between rotary transformer (8) (9), the reference surface of the fixed cylinder (2) (21)
(1) As the height H ₃ of the mounting surface (61) is constant, also the fitting portion of the rotary cylinder (1) and flywheel (3) rotational axis
After the fitting portion is cut so as to be concentric with (4), the rotary cylinder (1) is fitted to the flywheel (3) and fixed with screws (10).

The head drum having the above structure has a gap G ₀ between the rotary transformers (8) and (9), a fixed cylinder reference surface (21).
From to the magnetic head (7) the height H _0, the rotation cylinder (1)
All the concentricity of the tape sliding surface (11) with respect to the rotation axis (4) can be ensured, but there is a disadvantage that the number of parts increases.

As shown in FIG. 1, if the rotary shaft (4) is simply press-fitted and fixed directly to the rotary cylinder (1) and the flywheel (3) is omitted, the number of parts is reduced. Clearance G ₀ between transformers (8) and (9), fixed cylinder
From the reference plane (2) (21) in order to secure the height H ₀ to the magnetic head (7) is a high processing accuracy is required in the single item of each component, the yield is deteriorated.

According to the present invention, the gap between the rotary transformers is kept within an allowable range without reducing the number of parts and without increasing the precision of the parts, and the mounting height error of the magnetic head from the reference plane is reduced. The purpose of the present invention is to clarify a method of assembling a head drum that can be set within a certain range.

[0009]

According to the head drum of the present invention, the rotating shaft (4) penetrates the axis of the fixed cylinder (2) via the bearing (5), and the exposed end of the rotating shaft (4) rotates. The rotary cylinder (1) and the fixed cylinder (2) are fitted directly into the holes (18) in the axial center of the cylinder (1) and fixed, respectively.
And a fixed rotary transformer (9) are opposed to each other with a gap within an allowable range, and a magnetic head is attached to the rotary cylinder (1).
(7) A method of assembling a head drum provided with a fixed cylinder (2) of the reference plane (21) from the rotating cylinder (1) until the end faces of the abutting bearing (5) the height H ₁ and the fixed rotary depending from the transformer (9) to the height G ₁ until the end face of the bearing (5), from the bearing the bearing contacting surfaces of the rotating cylinder (1) with respect to (5) (12) to the magnetic head mounting surface (13) the height H ₂ and the magnetic head mounting surface to adjust the height G ₂ from the bearing contacting surfaces (12) to rotate the rotary transformer attachment surface (14)
(13) After adjusting and cutting the rotary rotary transformer mounting surface (14), the rotary cylinder (1) and the magnetic head (7) are mounted, and then the rotary cylinder (1) and the fixed cylinder (2) are assembled.

Another aspect of the present invention relates to a height H ₂ from the bearing abutment surface (12) of the rotary cylinder (1) to the magnetic head mounting surface (13) with respect to the bearing (5) and a bearing abutment surface (13). to adjust the rotational rotary transformer attachment surface (14) to a height G ₂ from 12) the magnetic head mounting surface of the rotating cylinder (1) (13) and the rotating rotary transformer mounting surface a spacer instead of processing (14) It is characterized by being interposed.

Still another aspect of the present invention is a magnetic head mounting surface from a bearing abutment surface (12) of a rotary cylinder (1) to a bearing (5).
Up (13) the height H _2, and the height G ₂ from the bearing contacting surfaces (12) to rotate the rotary transformer attachment surface (14) instead of adjusting the cutting each case, their height H _2, G _{For 2} , several types of rotating cylinders (1) having different dimensions are prepared in advance, and the rotating cylinder (1) having the optimal dimensions is fixed to the fixed cylinder (2).
Combine with

[0012]

[Action and Effect] Depending from the fixed rotary transformer fixed cylinder (2) (9) to the height G ₁ to the upper surface of the bearing (5), rotating the rotary from the bearing contacting surfaces of the rotating cylinder (1) (12) the G ₂ transformer (8) processing the height, and the reference plane from (21) to the bearing upper surface height H ₁ of the stationary cylinder (2)
Depending on, by processing a bearing abutment magnetic head mounting surface from the surface (12) (13) to a height height to G ₂ of the rotary cylinder (1), rotated through the rotary shaft (4) Cylinder By combining (1) and fixed cylinder (2), rotary transformer
(8) The gap G ₀ between (9) and the reference surface (21) of the fixed cylinder (2)
The height H ₀ to the magnetic head (7) can can be accommodated in the permissible range, also is not necessary to increase the precision of the parts separately.

Further, the number of parts can be reduced by directly fitting and fixing the rotating shaft (4) to the rotating cylinder (1).

[0014] Instead of adjusting the cutting dimension H ₂ and G ₂ of the rotating cylinder (1), even interposed spacers required locations, except that only the spacer component parts is increased, the same effect Play.

Instead of adjusting and cutting the dimensions H ₂ and G ₂ of the rotary cylinder (1) each time, a plurality of types having different dimensions are prepared in advance, and a rotary cylinder having an optimum dimension is selected. When assembled, the same effect as described above is achieved except for the trouble of preparing rotating cylinders having different dimensions.

[0016]

FIG. 1 shows an embodiment of a head drum according to the present invention. Two upper and lower bearings on the axis of the fixed cylinder (2)
(5) The rotating shaft (4) penetrates through (50), and the rotating shaft
The rotary cylinder (1) is press-fitted and fixed to the upper exposed end of (4). On the lower surface of the rotary cylinder (1), a bearing abutting surface (12) which is annularly protruded along the edge of the press-fit hole (18) is formed, and the bearing abutting surface (12) is provided on the upper bearing (5). ) Is pressed against the inner ring (51).

The lower surface of the rotary cylinder (1) is
Two concave surfaces (17) are opened, and the magnetic head (7) is fixed to the bottom of the concave surface (17) serving as the magnetic head mounting surface (13) by screws (71) via a mounting plate (72). Rotary rotary transformers are provided on the facing surfaces of the rotating cylinder (1) and the fixed cylinder (2), respectively.
(8) and the fixed rotary transformer (9) are adhered and fixed, and a gap G within an allowable range is provided between the rotary transformers (8) and (9).
0 is formed.

[0018] from the bearing contacting surfaces of the rotating cylinder (1) (12), the lower surface of the reference plane of the magnetic head mounting surface (13) to a height H ₂ is in a fixed cylinder in FIG. 1 (2) (21) the height H ₀ to the magnetic head (7) from the inner ring gave a preload downward of the upper bearing from at stationary cylinder reference plane (21) in FIG. 3 (5)
As the difference between the height H ₁ to the upper end of (51) to adjust cutting the magnetic head mounting surface of the rotating cylinder (1) (13). That is, the magnetic head mounting surface (13) is processed so that H ₂ = H ₁ −H ₀ .

Also, in FIG. 2, the rotary abutting surface (12) of the rotary cylinder (1) extends from the rotary rotary transformer mounting surface (14).
In fixed rotary transformer to the height G ₂ is 3 to
From the height G1 to the upper end of the downwardly on the inner ring gave a preload the upper bearing from the upper surface (9) (5) (51), in the rotary transformer (8) in FIG. 1 (9) the gap G ₀ between and processing the rotating rotary transformer attachment surface of the reduced value and becomes the rotation as the cylinder thickness G ₃ (1) (14) of at rotating rotary transformer (8) in FIG. That processed G ₂ = G ₁ -G ₀ rotation -G _three become like rotary transformer attachment surface (14).

By machining the magnetic head mounting surface (13) of the rotary cylinder (1) as described above, the fixed cylinder (2)
The height H ₀ from the reference surface (21) of the magnetic head (7) to the magnetic head (7) depends on the variation in processing of the magnetic head mounting surface (13) of the rotary cylinder (1) (within 5 μm) and the variation in magnetic head (within 40 μm). It falls within the range of the added variation (within 45 μm). or,
Since the rotary cylinder (1) is directly press-fitted and fixed to the rotary shaft (4), concentricity of the tape sliding contact surface (11) of the rotary cylinder (1) with respect to the rotary shaft (4) can be secured.

As shown by a two-dot chain line in FIG. 2, an annular concave portion (19) for applying an adhesive is formed on the rotary rotary transformer mounting surface (14) of the rotary cylinder (1) to abut the rotary transformer. If the variation due to the thickness of the adhesive layer of the rotary rotary transformer (8) can be ignored by providing a step between the surface and the bonding surface, etc., the rotary rotary transformer mounting surface (14 ), The gap G0 between the rotary transformers (8) and (9) can be made to vary according to the processing variation (within 5 μm) of the rotary rotary transformer mounting surface (14) of the rotary cylinder (1) and the rotary rotary transformer (8). ) Thickness variation of G3 (20μ)
(within 25 m).

As described above, the head drum of the present invention is shown in FIG.
Flywheel compared to conventional head drums
(3) The spacer (6) for adjusting the gap of the rotary transformers (8) and (9) and the screw (10) for fixing the rotary cylinder (1) to the flywheel (3) become unnecessary.

As shown in FIG. 2, the rotary rotary transformer (8) is directly press-fitted and fixed to the rotary cylinder (1) to directly connect the winding (14a) of the rotary rotary transformer (8) to the magnetic head (14). 7), and the connection terminals (15) and (16) for connecting the magnetic head (7) and the rotary rotary transformer (8) are unnecessary as in the conventional example shown in FIG.

In the above embodiment, the heights H ₂ and G ₂ from the bearing abutment surface (12) of the rotary cylinder (1) to the magnetic head mounting surface (13) and the rotary rotary transformer mounting surface (14) are determined. The case of adjusting and cutting the magnetic head mounting surface (13) and the rotary rotary transformer mounting surface (14) has been described.
The height H ₂ and G ₂ of the rotary cylinder (1) from the bearing abutment surface (12) to the magnetic head mounting surface (13) and from the bearing abutment surface (12) to the rotary rotary transformer mounting surface (14) are measured in advance. Different types of rotary cylinders (1) are prepared, or between the rotary rotary transformer mounting surface (14) and the rotary rotary transformer (8), and between the magnetic head mounting surface (13) and the magnetic head (7). Even if a spacer (not shown) is inserted between them, the same effect as described above can be obtained. The present invention is not limited to the configuration of the above embodiment, and various modifications can be made within the scope described in the claims.

[Brief description of the drawings]

FIG. 1 is a sectional view of a head drum according to the present invention.

FIG. 2 is a sectional view of a rotary cylinder into which a rotary shaft is press-fitted.

FIG. 3 is a sectional view of a fixed cylinder.

FIG. 4 is a bottom view of the rotary cylinder.

FIG. 5 is a sectional view of a conventional head drum.

[Explanation of symbols]

 (1) Rotary cylinder (12) Bearing abutment surface (13) Magnetic head mounting surface (14) Rotary rotary transformer mounting surface (2) Fixed cylinder (4) Rotary shaft (5) Bearing (7) Magnetic head (8) Rotation Rotary transformer (9) Fixed rotary transformer

Claims (3)

(57) [Claims] A rotary shaft (4) penetrates through an axis of a fixed cylinder (2) via a bearing (5), and a tip end of the rotary shaft (4) has a hole (5) in the axis of the rotary cylinder (1). 18) directly fits and is fixed,
A rotary rotary transformer (8) and a fixed rotary transformer (9) are provided oppositely to the rotary cylinder (1) and the fixed cylinder (2), respectively, with a gap within an allowable range.
A method of assembling a head drum provided with a magnetic head (7) in (1), wherein the rotating cylinder (1) is brought into contact with an upper end surface of a bearing (5) in advance.
Forming the butting surface (12), the reference surface (21) of the fixed cylinder (2)
From the fixed rotary transformer (9) to the upper end surface of the bearing (5).
Depending on the 1, the magnetic head mounting surface (13) and the rotating rotary transformer attachment surface (14) to adjust the cutting, the rotary cylinder
From the bearing contact surface (12) of (1) to the magnetic head mounting surface (13)
Rotary rotary from height H2 and bearing abutment surface (12)
After adjusting the height G2 to the transformer mounting surface (14) , the magnetic head (7) is mounted on the rotary cylinder (1), and then the rotary cylinder (1) and the fixed cylinder (2) are assembled. A method for assembling a head drum of a magnetic recording / reproducing apparatus. 2. A rotary shaft (4) penetrates through an axis of a fixed cylinder (2) via a bearing (5), and a tip end of the rotary shaft (4) has a hole (3) in the axis of the rotary cylinder (1). 18) directly fits and is fixed,
A rotary rotary transformer (8) and a fixed rotary transformer (9) are provided oppositely to the rotary cylinder (1) and the fixed cylinder (2), respectively, with a gap within an allowable range.
A method of assembling a head drum provided with a magnetic head (7) in (1), wherein the rotating cylinder (1) is brought into contact with an upper end surface of a bearing (5) in advance.
Forming the butting surface (12), the reference surface (21) of the fixed cylinder (2)
The height of the magnetic head mounting surface according to the height H1 from the shaft to the upper end surface of the bearing (5) with which the rotary cylinder (1) abuts and the height G1 from the fixed rotary transformer (9) to the upper end surface of the bearing (5). interposed a spacer between (13) and between the rotating rotary transformer attachment surface of the magnetic head (7) and (14) and the rotating rotary transformer (8), rotating cylinder with respect to the bearing (5)
Da magnetic head mounting surface of the bearing contacting surfaces (12) (1) (13)
From the height H2 to the bearing contact surface (12)
ー After adjusting the height G2 to the transformer mounting surface (14)
And a method of assembling a head drum of a magnetic recording / reproducing apparatus, comprising assembling a rotary cylinder (1) and a fixed cylinder (2). 3. A rotary shaft (4) penetrates through an axis of a fixed cylinder (2) via a bearing (5), and a tip end of the rotary shaft (4) has a hole (3) in the axis of the rotary cylinder (1). 18) directly fits and is fixed,
A rotary rotary transformer (8) and a fixed rotary transformer (9) are provided oppositely to the rotary cylinder (1) and the fixed cylinder (2), respectively, with a gap within an allowable range.
A method for assembling a head drum provided with a magnetic head (7) in (1), comprising: a bearing abutment for a rotating cylinder (1) in contact with an upper end surface of a bearing (5).
And the height H1 from the reference surface (21) of the fixed cylinder (2) to the upper end surface of the bearing (5) and the height H1 from the fixed rotary transformer (9) to the end surface of the bearing (5). According to the height G1, the height H2 from the bearing contact surface (12) of the rotary cylinder (1) to the bearing (5) to the magnetic head mounting surface (13) and the rotary rotary transformer from the bearing contact surface (12). Mounting surface
A plurality of types of rotating cylinders (1) having different heights from the height G2 up to (14) are prepared in advance, and fixed cylinders are prepared.
(2) Fixed rotary transformer (9) to rotary cylinder
Select the rotating cylinder (1) according to the dimension up to the upper end of the bearing (5) on the (1) side, and select the rotating cylinder (1) and the fixed cylinder.
(2) A method for assembling a head drum of a magnetic recording / reproducing apparatus, which comprises assembling (2).