JP3151030B2 - Cylinder device for magnetic recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder device for a magnetic recording / reproducing apparatus.

[0002]

2. Description of the Related Art In recent years, as a magnetic recording / reproducing apparatus (hereinafter, referred to as a VTR) has become smaller and thinner, a cylinder device in a VTR has also become smaller and thinner. The applicant has already proposed this type of apparatus in Japanese Patent Application No. 2-304068 (hereinafter referred to as a conventional example). In this proposal, a cylinder drive motor provided in the lower portion of a conventional cylinder is inserted into the cylinder to reduce the thickness of the cylinder. FIG.
FIG. 2 is a side sectional view of a cylinder device (hereinafter, referred to as the present device) of the magnetic recording / reproducing device proposed above. In FIG. 3, the present apparatus is composed of a fixed lower cylinder 1 and a rotating upper cylinder 2. A rotary transformer is provided in the lower cylinder 1, and a motor is provided in the upper cylinder.

Next, a conventional method of assembling the present apparatus will be described with reference to FIG. In FIG. 3, first, the fixed side 7 of the rotary transformer is bonded to the lower cylinder 1,
Is bonded to the bearing unit 16 with a shaft assembled in the transformer base 6. The shaft 15 of the bearing unit with a shaft to which the rotary transformer is bonded is press-fitted into the lower cylinder 1 while controlling the gaps of the rotary transformers on the rotating side and the fixed side. After that, the upper cylinder unit is assembled, and the motor is assembled.

[0004]

However, in the above conventional example, in order to press-fit the bearing unit with a shaft into the lower cylinder, it is necessary to strictly control the inclination accuracy of the shaft with respect to the lower cylinder. Further, since the gap is set while press-fitting, the press-fitting increases. Therefore, it is necessary to strictly control the gap due to the deformation of the shaft bending and its return. When a gap failure or the like due to dust or the like occurs, it is impossible to reassemble, so it is necessary to take measures to prevent the dust or the like from being mixed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has as its object to improve the precision of a gap and reduce defective products, and to obtain a highly accurate, inexpensive and lightweight apparatus. .

[0006]

For this reason, in the present invention, a recording medium travels around the outer periphery of a fixed cylinder and a rotary cylinder rotatably supported by the fixed cylinder, and performs recording and reproduction on the recording medium. In a cylinder device of a magnetic recording / reproducing apparatus, a fixed shaft disposed on a fixed cylinder, a transformer base fitted to the fixed shaft and holding a rotary transformer and a rotary cylinder, and a pair of a pair mounted on the transformer base. A bearing, a preload means for applying a preload to the bearing, and a pedestal that is fitted to the fixed shaft and locked at a predetermined position, and by the preload means and the pedestal,
An object of the present invention is to solve the above problems and achieve the object by a cylinder device of a magnetic recording / reproducing apparatus in which a preload is applied to the pair of bearings to adjust a gap of the rotary transformer.

[0007]

The magnetic recording / reproducing apparatus according to the present invention is mounted on a transformer base which fits on a fixed shaft and holds a rotary transformer and a rotary cylinder, and is fitted on a fixed shaft with preload means for applying a preload to a pair of lower bearings. While adjusting the gap of the rotary transformer with the pedestal that locks in place.
Apply preload to the pair of bearings.

[0008]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view of a cylinder device of a magnetic recording and reproducing apparatus according to one embodiment of the present invention, and FIG. 2 is an exploded side sectional view of a lower cylinder unit in FIG.

In FIGS. 1 and 2, a fixed shaft 3 is provided upright at the center of the lower cylinder 1. Transformer stand 6
The inner sides of the bearings 4 and 5 that rotatably support are fixed to the fixed shaft 3, and the outer sides are fixed to the transformer base 6. Lower cylinder 1
And the transformer base 6, each having a fixed rotary transformer 7
And the rotary rotary transformer 8 are fixed. The head support 9 is adjusted so that the magnetic head 19 has a predetermined height and angle with respect to the rotating upper cylinder 2. The upper cylinder 2 is fitted to a transformer base 6 and further fixed by screws 6c. A rotor magnet unit 10 for a cylinder driving motor is mounted on the upper cylinder 2, and a motor base 12 fixed on the upper part of the fixed shaft 3 has a stator coil unit 11 facing the rotor magnet 10.
Is installed. A preload member 13 and a preload spring 14 are provided between the lower cylinder 1 and the bearing 5 to apply a preload to each of the bearings 4 and 5. Since the transformer base 6 is lifted by the preload spring 14, the gap 7a between the rotary transformers 7 and 8 is set while pressing the motor pedestal 12, and the gap is set at a predetermined position.
Is fixed. Preload is applied to each of the bearings 4 and 5 by the preload member 13 and the end face of the motor base 12 on the bearing 4 side.

A magnetic tape (not shown) skews on the outer circumference of the lower and upper cylinders 1 and 2, the upper cylinder 2 is driven to rotate by motors 10 and 11, and signals are recorded and reproduced by the magnetic head 9.

Next, a method of assembling the lower cylinder portion of this embodiment will be described with reference to FIG. In FIG. 2, first, a center fixed shaft 3 is fixed to the lower cylinder 1 by so-called shrink fitting. `` Bake shrink '' is a method of heating a member with a hole to a high temperature, expanding it, expanding the hole diameter, inserting the shaft to a predetermined position, cooling it, and fixing the shaft uniformly without applying excessive stress Because it is cooled, it is fixed with high accuracy without falling down according to the processing accuracy. The fixed rotary transformer 7 is fixed to the lower cylinder 1 by bonding or the like.
Next, each of the bearings 4 and 5 is fixed to the transformer base 6 by shrink fitting, and the mounting surface 6a and the fitting portion 6b of the upper cylinder 2 are fixed to a predetermined position with reference to the shaft fitting portion inside the bearing. After processing to obtain the accuracy, the upper cylinder 2 is mounted. Thereafter, the rotary side 8 of the rotary transformer is fixed to the transformer base 6 by bonding or the like. Next, the preload spring 14 and the preload member 13 are inserted into the fixed shaft 3, and the separately assembled transformer base 6 is inserted into the fixed shaft 3 so that the bearings 4 and 5 respectively fit. Finally, the motor pedestal 12 is inserted into the fixed shaft 3 and fixed by screws or the like. The gap 7a (FIG. 1) of each of the rotary transformers 7 and 8 can be freely adjusted by pressing the motor base 12 and fixing it at a predetermined position while measuring mechanical dimensions or inductance.

[0012]

As described above, according to the present invention, the fixed shaft is assembled to the fixed cylinder and the transformer base is inserted into the shaft later, so that the shaft can be fixed by shrinkage fitting. , And the accuracy of the verticality with respect to the fixed cylinder was remarkably improved. Further, the thickness of the fixed cylinder can be made thinner and the rigidity can be made smaller than in the conventional case, which greatly contributes to weight reduction. Also, due to the repulsive force of the preload means,
Since the gap of the rotary transformer is large when the transformer base is fitted, the gap can be adjusted while pushing the motor base. In addition, variations due to shaft deformation return, difficulties in checking once assembled, and re-adjustment when the gap is clogged due to excessive press-fitting can all be solved. Decreased. Also, by pushing the transformer stand,
The gap can be reconfirmed. These effects make it possible to manufacture an accurate, inexpensive and lightweight cylinder device.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a cylinder device of a magnetic recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is an exploded side sectional view of the cylinder unit in FIG. 1;

FIG. 3 is a side sectional view of a cylinder device in a conventional magnetic recording / reproducing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lower cylinder 2 Upper cylinder 3 Fixed shaft 4,5 Bearing 7,8 Rotary transformer 12 Motor pedestal 13 Preload member 14 Preload spring

Continuation of the front page (56) References JP-A-58-137132 (JP, A) JP-A-63-269314 (JP, A) JP-A-63-1410 (JP, U) JP-A-3-66015 (JP) , U) (58) Field surveyed (Int.Cl. ⁷ , DB name) G11B 5/02 G11B 5/52 102

Claims (1)

(57) [Claims] In a cylinder device of a magnetic recording / reproducing apparatus in which a recording medium travels around an outer periphery of a fixed cylinder and a rotating cylinder rotatably supported by the fixed cylinder, and performs recording and reproduction on the recording medium, A fixed shaft disposed, a transformer base fitted to the fixed shaft and holding a rotary transformer and a rotary cylinder, a pair of bearings mounted on the transformer base, and a preload means for preloading the bearing; A pedestal that is fitted to the fixed shaft and locked at a predetermined position, and by the preload means and the pedestal,
A cylinder device for a magnetic recording / reproducing apparatus, wherein a preload is applied to said pair of bearings to adjust a gap of said rotary transformer.