JPH06274843A - Rotary magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To provide a rotary magnetic recording and reproducing device whose friction torque of a bearing is prevented from increasing, and then, whose current consumption of a motor is prevented from increasing and with excellent rotational precision. CONSTITUTION:This device is provided with a rotary drum part 60 provided with an upper fixed drum 21, a lower fixed drum 23 and a head 18, and arranged between the upper fixed drum 21 and the lower fixed drum 23 rotatably around a shaft 34. Then, the rotary drum part 60 and a support part 61 supporting the rotary drum part 60 rotatably for the shaft 34 are formed integrally.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary magnetic recording device used in a VTR device, a DAT or the like.

[0002]

2. Description of the Related Art A conventional rotary magnetic recording device has a structure as shown in FIG. In FIG. 3, this rotary magnetic recording apparatus has a so-called three-layer structure, and includes an upper fixed drum 1, a lower fixed drum 3, and a rotary drum assembly 2.
have.

A shaft 14 is press-fitted into an upper fixed drum 1, which is also called an upper fixed cylinder, and a sleeve 15 is rotatably attached to the shaft 14. A rotary drum 17 and a head 18 are attached to the sleeve 15.

The rotor 15 of the motor is attached to the sleeve 15 near the lower end thereof. Then, a voltage is applied from the motor drive circuit 25 to the stator 13 of the motor through the stator flexible substrate 7, so that the rotating portion including the sleeve 15, the rotating drum 17, the head 18, and the rotor 4 starts to rotate. It has become.

[0005]

By the way, the rotary drum assembly 2 has a structure as shown in FIG. The rotary drum assembly 2 is composed of the rotary drum 17 of the rotary part, the sleeve 15 and the core 16 on the rotary side of the rotary transformer. The sleeve 15 is made of brass, and the sleeve 15 is press-fitted and assembled to a rotary drum 17 made of aluminum. Then, the rotary core 16 of the rotary transformer is bonded to the rotary drum 17,
Moreover, the head 18 of FIG. 3 is attached.

Therefore, when the sleeve 15 is press-fitted, the sleeve 15 is mechanically deformed toward its inner diameter side. That is, the gap formed between the outer circumference of the shaft 14 and the inner circumference of the sleeve 15 in FIG. 3 is narrowed, and the bearing friction torque is increased. Therefore, not only the rise time at the time of starting the motor becomes long, but also the power consumption of the motor increases. When the conventional rotary magnetic recording device in which the power consumption of this motor is large is used for portable audio, the usable time per battery is shortened because the rotary magnetic recording device is driven by a small battery. There was a problem.

Also, as described above, the sleeve 1 shown in FIG.
When press-fitting 5 into the rotary drum 17,
Causes mechanical deformation toward the outer diameter side, and the accuracy of the roundness of the outer periphery a of the rotating drum 17 which has been already machined and finished with high accuracy and the accuracy of the flatness of the end surface b are deteriorated.

Furthermore, if the rotary drum 17 is pressed into the sleeve 15 while being inclined, when the rotary drum assembly 2 shown in FIG. There is a problem that the swing becomes large and the rotation accuracy of the rotary drum 17 is impaired.

The present invention has been made in order to solve the above-mentioned problems, and the bearing friction torque does not increase, so that the current consumption of the motor does not increase and the rotation accuracy is good. Is intended to provide.

[0010]

In the present invention, the above object is to provide an upper fixed drum, a lower fixed drum, a head, and a shaft as a center between the upper fixed drum and the lower fixed drum. A rotary magnetic recording device comprising a rotatable drum portion rotatably arranged, wherein the rotatable drum portion and a support portion for rotatably supporting the rotatable drum portion with respect to the shaft are integrally formed members. Is achieved by Further, in the present invention, preferably, the support portion is sleeve-shaped. Further, in the present invention, a fluid bearing is preferably formed between the shaft and the support portion.

[0011]

Since the rotary drum portion and the support portion for rotatably supporting the rotary drum portion with respect to the shaft are formed as an integrally formed member, mechanical deformation at the time of assembly, which has conventionally occurred, does not occur. . Further, the accuracy of the rotary drum portion can be maintained.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the examples described below are suitable specific examples of the present invention, and therefore, various technically preferable limitations are given, but the scope of the present invention particularly limits the present invention in the following description. Unless otherwise stated, the present invention is not limited to these modes.

FIG. 1 shows a preferred embodiment of the rotary magnetic recording apparatus of the present invention. In FIG. 1, the rotary magnetic recording apparatus is a rotary head drum apparatus also called a rotary magnetic recording apparatus having a so-called three-layer structure, which includes an upper fixed drum 21, a lower fixed drum 23, and a rotary drum assembly 22.

Upper fixed drum 21 also called upper fixed cylinder
The shaft 34 is press-fitted in the cantilevered state. The shaft 34 faces vertically downward. on the other hand,
The lower fixed drum 23, which is also referred to as a lower fixed cylinder, is fixed while maintaining a relative position with respect to the upper fixed drum 21 via a drum support 40.

Upper fixed drum 21 and rotating drum assembly 22
A rotary transformer 48 is set between them. The rotary transformer 48 exchanges signals between the upper fixed drum 21 and the rotary drum assembly 22, and is composed of a fixed core 56 and a rotary core 58. The fixed core 56 is fixed to the lower surface of the upper fixed drum 21. On the other hand, the rotating core 58 is one component of the rotating drum assembly 22.

The rotary drum assembly 22 has a structure as shown in FIG. The rotary drum assembly 22 includes a rotary drum member 19, the core 58 on the rotating side fixed to the upper surface of the rotary drum member 19, and a ball 59. As is apparent from FIG. 2, the rotary drum member 19 of the rotary drum assembly 22 is different from the rotary drum member 60 of the conventional rotary drum assembly shown in FIG.
This is characterized in that the sleeve portion 61 and the sleeve portion 61 are integrally formed of the same material. The rotary drum member 19 can be integrally formed of brass or brass, for example.

The sleeve portion 61 is a support member that rotatably supports the rotary drum portion 60 with respect to the shaft 34 between the upper fixed drum 21 and the lower fixed drum 23. This sleeve portion 61 is attached to the shaft 34
It is partially surrounded by. The core 58 on the rotating side is fixed by an adhesive on the upper surface of the rotating drum portion 60. The magnetic recording head 18 is attached to the rotary drum portion 60 as shown in FIG.

Referring back to FIG. 1, the rotor portion R of the motor M is attached to the lower end of the sleeve portion 61 of the rotary drum member 19. On the other hand, the stator portion 33 of the motor M
Drive circuit 2 via stator flexible substrate 37.
Connected to 5. The stator portion 33 and the rotor portion R
Constitute a motor M.

The motor M includes a magnetic path plate 29, a motor shield case 26, a gear 38, a shim 42 and the like.
Further, the fishbone-shaped groove 20 is formed on either the outer peripheral surface of the shaft 34 or the inner surface of the sleeve portion 61 of the rotary drum member. Thereby, the rotary drum member 19
The sleeve portion 61 and the shaft 34 constitute a fluid bearing.

Next, the operation of the above configuration will be described.
As shown in FIG. 2, in the embodiment of the present invention, the rotary drum member 19 is a single component in which the sleeve portion 61 and the rotary drum portion 60 are integrally molded. Therefore, unlike the prior art, no assembly work for fixing the sleeve to the rotary drum by press fitting is required, so that mechanical deformation does not occur in the sleeve portion 61 and the shaft 3
There is no fear that the gap formed between the bearing 4 and the bearing portion which is the sleeve portion 61 is narrowed. Therefore, the bearing friction torque of the fluid bearing that requires precision is constant, and the current consumption of the motor M does not increase.

Further, since the assembling work by press-fitting which has been conventionally performed is not required, the rotary drum portion 60 is of course not mechanically deformed. Therefore, the precision of the rotary drum portion 60 of the rotary drum member 19 that has been processed and finished with high precision in advance, that is, the roundness of the outer peripheral portion A of the rotary drum portion 60 and the precision of the flatness of the end surface B are maintained. As it is, the rotary magnetic recording device can be easily assembled. Therefore,
After being assembled, the rotary drum member 19 has the central axis CL.
There is no possibility that the rotary drum member 19 will rotate with respect to the central axis CL even if it rotates.

The present invention is not limited to the above embodiment. For example, the rotary drum member 19 shown in FIG.
The shape is not limited to the above shape, and may be another shape.

[0023]

As described above, according to the present invention,
Since the rotary drum portion and the support portion that rotatably supports the rotary drum portion with respect to the shaft are formed as an integral member, the assembly work by press fitting that has been conventionally performed is not required. Therefore, the gap between the supporting portion and the shaft is not narrowed, the bearing friction torque is not increased, and the current consumption of the motor is not increased.
Further, since the assembly work by press-fitting is not required, there is no mechanical deformation of the rotary drum portion, and the rotary magnetic recording device can be assembled and used while maintaining the accuracy as it is already processed and finished. . Therefore, during this use, there is no rotational runout and high rotational accuracy can be maintained.

[Brief description of drawings]

FIG. 1 is a sectional view showing a preferred embodiment of a rotary magnetic recording apparatus of the present invention.

FIG. 2 is a sectional view showing a rotary drum assembly of the rotary magnetic recording apparatus of FIG.

FIG. 3 is a cross-sectional view showing a conventional rotary magnetic recording device.

4 is a sectional view showing a rotary drum assembly in the conventional rotary magnetic recording apparatus of FIG.

[Explanation of symbols]

 21 Upper Fixed Drum 22 Rotating Drum Assembly 23 Lower Fixed Drum 60 Rotating Drum Part 61 Sleeve Part (Supporting Part) M Motor

Claims (3)

[Claims] 1. An upper fixed drum, a lower fixed drum, and a rotary drum portion which has a head and is rotatably arranged about a shaft between the upper fixed drum and the lower fixed drum. A rotary magnetic recording device, wherein the rotary drum portion and a support portion that rotatably supports the rotary drum portion with respect to the shaft are formed by integrally formed members. 2. The rotating magnetic recording apparatus according to claim 1, wherein the supporting portion is sleeve-shaped. 3. Between the shaft and the support portion,
The rotary magnetic recording apparatus according to claim 1, wherein a fluid bearing is formed.