JPH07147001A - Rotary drum device - Google Patents

Abstract

PURPOSE:To make a rotary drum device small in size and light in weight and to enhance the performance thereof by enabling a rotary transformer to be fitted to a shaft driven by a drum motor. CONSTITUTION:The shaft 7 is made hollow so as to be provided with a wiring passing hole 19 or the surface of the shaft 7 is provided with a wiring passing groove 20. Then, wiring 16' is executed between the rotor part 12 of the rotary transformer 1 and a rotary plate on which a rotary head is mounted through the hole 19 or the groove 20. Therefore, the cylindrical transformer 1 can be provided in the shaft supporting part 8 of the inside diameter side of a lower fixed drum where the shaft 7 pierces. Besides, the rotor part 12 is fixed to the shaft 7 and the wiring 16' can be connected to the rotor part 12. Then, wiring 16 is connected to the stator 18 of the transformer 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary drum device in a helical scan type recording / reproducing device.

[0002]

2. Description of the Related Art A helical scan recording / reproducing apparatus is provided with a rotary drum device having a rotary head, and the rotary head scans a recording tape at a high speed to record / reproduce signals in a wide band.

In particular, recently, in order to have many functions such as simultaneous recording / reproduction and special reproduction, the number of rotary heads mounted tends to increase, and the recording frequency increases as the recording density improves. Tends to become. For this reason, as the rotary transformer provided in the rotary drum device, a cylinder type in which the number of channels is easily increased and the characteristic difference between the channels is small is increasingly adopted.

Further, there is a strong demand for downsizing of the entire system, and it is essential to reduce the size and weight of the rotary drum device in the future.

An example of a conventional rotary drum device will be described with reference to FIG. However, 1 is a rotary transformer, 2
Is a rotary head, 3 is an upper fixed drum, 4 is a lower fixed drum,
5 is a drum motor, 6 and 6'are bearings, 7 is a shaft, 8
Is a shaft support part, 9 is a rotary plate, 10 is a lead, 11 is a bearing fitting, and 12 is a rotor part.

In the figure, an upper fixed drum 3 and a lower fixed drum 4 provided with a lead 10 for guiding a magnetic tape (not shown) on the outer surface are arranged so as to face each other, and an internal space between them is provided. A rotary plate 9 is provided inside. The rotary plate 9 is fixed to the shaft 7 that rotates integrally with the rotor portion 12 of the drum motor 5. The stator portion of the drum motor 5 is fixed to the lower fixed drum 4. Shaft 7
Penetrates the shaft support portion 8 inside the lower fixed drum 4,
The shaft support 8 is rotatably supported by bearings 6 and 6 ′ attached to the upper and lower ends thereof. Also,
The rotary head 2 is attached to the rotary plate 9 so as to slightly project outside from a slight gap between the upper fixed drum 3 and the lower fixed drum 4.

A cylindrical rotary transformer 1 for transmitting signals between the rotary head 2 side and a signal processing circuit side (not shown) is arranged in a space inside the lower fixed drum 4.
The rotor portion is attached to the lower portion of the rotary plate 9, and the stator portion is attached to the lower fixed drum 4 so as to face each other.

[0008]

However, in the above-described conventional rotary drum device, the cylindrical rotary transformer has the ease of assembling into the rotary drum device taken into consideration.
It was arranged above the two bearings 6 and 6 ', or outside the bearings 6 and 6'as shown in FIG. However, when the rotary transformer 1 is arranged above the bearings 6 and 6 ', the entire height of the rotary drum device becomes high, and when the rotary transformer 1 is arranged outside the bearings 6 and 6'. The diameter of the rotary drum device is large, and in any case, it is not suitable for downsizing the rotary drum device.

In order to solve this, when the rotary transformer 1 is arranged above the bearings 6 and 6'as described above, the distance between the two bearings 6 and 6'is shortened, and the rotary transformer 1 is also reduced. When the transformer 1 is arranged outside the bearings 6 and 6 ', a method of reducing the diameter of the shaft 7 and the diameter of the bearings 6 and 6'can be considered, but the distance between the two bearings 6 and 6'is shortened. In this case, the runout of the rotary part of the rotary drum device increases, and when the diameters of the shaft 7 and the bearings 6 and 6 ′ are reduced, the rigidity of the rotary part of the rotary drum device decreases, and However, the reliability of the rotary drum device is lowered and it cannot be adopted.

Further, in the conventional cylindrical rotary transformer, due to its structure, it is difficult to align the rotor portion and the stator portion with each other, and a shaft runout of about 20 microns occurs even if the rotor portion and the stator portion are aligned with high accuracy. Taking into consideration the thermal deformation of No. 1, the gap between the rotor and the stator was required to be at least 30 microns or more. Therefore, the coupling coefficient of the rotary transformer is correspondingly reduced, and the performance of the rotary transformer is degraded.

An object of the present invention is to solve the above problems and to provide a rotary drum device having a small size and improved performance.

[0012]

In order to achieve the above object, according to the present invention, a rotary transformer is arranged between two bearings provided on an inner peripheral portion of a lower fixed drum to support a shaft, and the rotary transformer is provided. Wiring between the rotor portion of the transformer and the rotating portion on which the rotary head is mounted is provided in a wiring through hole or a wiring through groove provided along a longitudinal direction of a shaft integrated with the rotating portion.

Further, according to the present invention, the rotor portion of the rotary transformer is fixed to the shaft, the outermost peripheral portion of the rotor portion is machined with reference to the shaft, and similarly, the stator portion of the rotary transformer is fixed to the fixing member. The innermost peripheral portion of the stator portion is machined on the same axis as the bearing support portion of the fixed member.

[0014]

The wiring between the rotor part of the rotary transformer and the rotary member on which the rotary head is mounted can be performed via the shaft, and the rotor part of the rotary transformer is attached to the shaft which is rotationally driven by the drum motor. Signal transmission between the rotor portion and the rotary member of the rotary transformer becomes possible. Since the rotary transformer can be mounted and arranged on the shaft in this manner, the space near the shaft can be effectively used and the rotary drum device can be easily downsized. Further, since the distance between the two bearings of the shaft can be set sufficiently, the shaft runout can be reduced and the reliability of the rotary drum device is improved.

Further, the outermost peripheral portion of the rotor portion of the rotary transformer is machined on the basis of the shaft, and the innermost peripheral portion of the stator portion is machined on the same axis as that of the bearing support portion of the fixed member. It is possible to reduce the axial runout between the rotor portion and the stator portion, and consequently reduce the gap between the rotor portion and the stator portion. As a result, the coupling coefficient of the rotary transformer is increased, and the performance of the rotary drum device is further improved.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a sectional view showing an embodiment of a rotary drum device according to the present invention, in which 13 is a shaft metal fitting, 14 is a substrate,
Reference numeral 15 denotes a stator substrate, parts corresponding to those in FIG. 5 are designated by the same reference numerals, and redundant description will be omitted.

In the figure, the rotary plate 9 is attached to a shaft fitting 13 fixed to the shaft 7 with screws and rotates integrally with the shaft 7. The shaft support portion 8 through which the shaft 7 inside the lower fixed drum 4 penetrates is the drum motor 5
Of the bearings 6 and 6 ′ are provided at the lower end and the upper end of the shaft support 8 so that the shaft 7 can be rotated by these bearings 6 and 6 ′. Supported by. Then, the cylindrical rotary transformer 1 is attached from the bearing 6 to the bearing 6'in the shaft support portion 8. The rotor portion of the rotary transformer 1 is fixed to the shaft 7, and the stator portion is fixed to the inner surface of the shaft support portion 8. Therefore, the outer shape of the rotor portion of the rotary transformer 1 is
Smaller than 6'outline.

According to this structure, when compared with the conventional rotary drum device shown in FIG. 5, assuming that the rotary transformers 1 have the same length, there is nothing to be arranged in the inner space of the lower fixed drum 4, The height of the portion other than the shaft support portion 8 of the lower fixed drum 4 can be sufficiently reduced,
Accordingly, the drum motor 5 can be arranged closer to the upper fixed drum 3 side, and therefore, the height of the rotary drum device can be sufficiently shortened, and the rotary drum device can be considerably downsized.

Further, since the distance between the bearings 6 and 6'can be made sufficiently large, the shaft runout of the rotating portion can be made sufficiently small, and the reliability of the rotary drum device is improved.

2 (a) and 2 (b) are sectional views showing in detail a specific example of the configuration of the rotary transformer 1 and the bearing 6 in FIG. 1, wherein 16 and 16 'are wiring and 17 is 1 is a rotor portion of the rotary transformer 1, 18 is a stator portion, 19 is a wiring through hole, and 20 is a wiring through groove.
The same reference numerals are attached to the portions corresponding to.

In the specific example shown in FIG. 2A, the shaft 7
Has a cylindrical shape, and the wiring 16 'is formed in the wiring through hole 19 therein. One end of the wiring 16 ′ is led out to the outside at the rotary transformer 1 portion and connected to the rotor portion 17 of the rotary transformer 1. The other end of the wiring 16 ′ is led out to the outside at the upper end of the shaft 7 and soldered to the substrate 14 on which the preamplifier or the like mounted on the rotating plate 9 is arranged as shown in FIG. 1. ing.

The wiring 16 whose one end is connected to the stator portion 18 of the rotary transformer 1 is led out of the shaft support portion 8 and attached to the inner surface of the lower fixed drum 4 as shown in FIG. It is soldered to the stator substrate 15.

In the specific example shown in FIG. 2B, the shaft 7
A wiring through groove 20 is provided in a part of the outer surface of the wiring along the longitudinal direction thereof, and a wiring 16 'is formed in this. The other points are the same as those of the specific example shown in FIG.

As described above, the wiring between the rotor portion 17 of the rotary transformer and the rotary plate 9 is performed via the shaft 7, so that the rotary transformer 1 is installed in the shaft support portion 8 as shown in FIG. Even if it is arranged between the bearings 6 and 6 ', it is possible to transmit a recording signal and a reproduction signal through the rotary transformer 1, and as a result, it is possible to realize a rotary head device having the above effects.

FIG. 3 is a view showing the assembling process of this embodiment. Reference numerals 21 and 21 'are bearing support portions, and the portions corresponding to the above-mentioned drawings are designated by the same reference numerals.

1) The rotor portion 17 of the rotary transformer 1 is bonded to the shaft 7. The wiring 16 'at this time is as shown in FIG. After adhering the rotor portion 17, the outermost peripheral portion of the rotor portion 17 is processed with the shaft as a reference. Since the shaft is machined, the runout of the rotor part 17 is 2-3 μm.
It can be processed with a high degree of accuracy.

2) The stator portion 18 of the rotary transformer 1 is bonded to the inner surface of the shaft support portion 8 of the lower fixed drum 4. At this time, the wiring 16 is as shown in FIG. After adhering the stator part 18, the innermost circumference of the stator part 18 and the bearing support parts 21, 2 of the bearings 6, 6 ′ of the lower fixed drum 4.
1'and the same axis are processed. The height reference at this time is the lower surface of the lower fixed drum 4 shown in the figure. As a result, the innermost circumference of the stator portion 18 falls within a micron-order deflection with respect to the support portions of the bearings 6, 6 ′, and from the above 1), the deflection of the rotor portion 17 with respect to the stator portion 18 is at most 10 degrees.
It can be suppressed to μm or less. Therefore, even if the reduction in the gap between the stator portion 18 and the rotor portion 17 due to the thermal expansion of the rotary transformer 1 is considered to be about 10 μm, the stator portion 1
8. It is sufficient that the gap between the rotor portions 17 is about 20 μm (in this case, the difference between the inner diameter of the stator portion 18 and the outer diameter of the rotor portion 17 is about 40 μm). This is 10 μm or more narrower than the value of the cylindrical rotary transformer used in the conventional rotary drum device. Therefore, the coupling coefficient of the rotary transformer 1 is increased, and the performance of the rotary drum device is improved. The lead 10 may also be processed on the basis of the same axis.

3) The rotor portion 17 of the rotary transformer 1 is inserted into the stator portion 18, and thereafter, the bearings 6'and 6 are respectively attached to the bearing supporting portions 21 and 21 'from the upper end portion and the lower end portion of the shaft supporting portion 8. After the insertion, the bearings 6 and 6 ′ are press-fitted into the shaft support portion 8.

4) The rotor 17 is positioned in the vertical direction so that the coupling coefficient of the rotary transformer 1 is maximized, the pressurizing spring 24 is inserted on the drum motor 5 side, and the bearing fitting 11 is screwed. After that, shaft fitting 1
The shaft fitting 13 is screwed to the shaft 7 while applying a predetermined pressure to the shaft 3.

5) Then, the rotary plate 9 to which the rotary head 2 and the substrate 14 are attached, the drum motor 5 and the upper fixed drum 3 are attached to obtain the rotary drum device shown in FIG.

FIG. 4 is a partial cross-sectional view showing another embodiment of the rotary drum device according to the present invention, in which 1'is a rotary transformer and 25 is a cylindrical portion, and the portions corresponding to those in FIG. A duplicate description will be omitted.

In the figure, the rotary plate 9 is arranged so as to face the upper outer surface of the shaft support portion 8 of the lower fixed drum 4.
A cylindrical portion 25 protrudes from the lower surface of the above, and another rotary transformer 1'is provided between these shaft supporting portions 8 and 25. The rotor portion of the rotary transformer 1 ′ is fixed to the inner surface of the cylindrical portion 25, and the stator portion is fixed to the upper outer surface of the shaft support portion 8.

According to this embodiment, even if the size is the same as that of the embodiment shown in FIG. 1, the number of signal channels can be increased by the rotary transformer 1 ', and it is possible to cope with more multifunction.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments. For example, although the upper drum is fixed in each of the above embodiments, it may be a rotating drum. Needless to say, in this case, the rotary plate 9 is not necessary, and the upper drum is fixed to the shaft and the rotary head is attached to the upper drum.

[0035]

As described above, according to the present invention,
Recording signals and reproduction signals can be transmitted between the rotary transformer and the rotary member equipped with the head through the shaft, and the rotary transformer can be mounted on the shaft and arranged. The space in the vicinity can be effectively used, the miniaturization of the rotary drum device can be easily realized, and the distance between the two bearings supporting the shaft can be made sufficiently large, so that shaft runout can be reduced and the rotary drum device Improves reliability.

Further, by machining the outermost peripheral portion of the rotor portion of the rotary transformer on the basis of the shaft, and similarly, the innermost peripheral portion of the stator portion is processed on the basis of the same axis as the bearing support portion of the lower fixed drum. The shaft run-out between the rotor part and the stator part can be reduced, and as a result, the gap between the rotor part and the stator part can be reduced, and the coupling coefficient of the rotary transformer is increased to improve the performance of the rotary drum device. Is improved.

Further, the rotor portion of the drum motor can be arranged at the same height as between the two bearings, and the overall height of the rotary drum device can be reduced.

[Brief description of drawings]

FIG. 1 is a partial sectional view showing an embodiment of a rotary drum device according to the present invention.

FIG. 2 is a cross-sectional view showing in detail the vicinity of the rotary transformer in FIG.

FIG. 3 is an assembly process diagram of the embodiment shown in FIGS.

FIG. 4 is a partial cross-sectional view showing another embodiment of the rotary drum device according to the present invention.

FIG. 5 is a partial cross-sectional view showing an example of a conventional rotary drum device.

[Explanation of symbols]

 1, 1'Rotary transformer 2 Rotating head 3 Upper fixed drum 4 Lower fixed drum 5 Drum motor 6,6 'Bearing 7 Shaft 9 Rotating plate 10 Lead 11 Bearing metal fitting 12 Rotor part of drum motor 5 Shaft metal fitting 14 Board 15 Stator board 16, 16 'Wiring 17 Rotor part of rotary transformer 18 Stator part of rotary transformer 19 Wiring through hole 20 Wiring through groove 21,21' Bearing support part 24 Pressurizing spring

Front page continuation (72) Inventor Fukubira, 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa, Ltd. Inside Hitachi Media Media Research Laboratories

Claims (8)

[Claims] 1. A rotating member having a rotating head that rotates integrally with a shaft that is driven to rotate by a drum motor and a fixed member are arranged to face each other, and the shaft is mounted on a shaft support portion of the fixed member. Magnetic recording, which is rotatably supported by two bearings mounted in a supporting portion, and which transmits a recording signal to the rotary head and a reproduction signal from the rotary head via a rotary transformer. In a rotary drum device of a reproducing apparatus, a wiring through hole is provided in the shaft along a longitudinal direction thereof, and wiring is provided from the rotor portion of the rotary transformer to the rotary member in the wiring through hole. apparatus. 2. A rotating member having a rotating head that rotates integrally with a shaft that is driven to rotate by a drum motor and a fixed member are arranged to face each other, and the shaft is mounted on a shaft support portion of the fixed member. Magnetic recording, which is rotatably supported by two bearings mounted in a supporting portion, and which transmits a recording signal to the rotary head and a reproduction signal from the rotary head via a rotary transformer. In the rotary drum device of the reproducing apparatus, a wiring through groove is provided on the surface of the shaft along the longitudinal direction thereof, and the wiring through groove is provided with wiring from the rotor portion of the rotary transformer to the rotating member. Rotating drum device. 3. The rotary drum device according to claim 1, wherein the rotary transformer has a cylindrical shape and is arranged between the two bearings in the shaft support portion. 4. The drum motor according to claim 1, wherein a part or all of the drum motor passes through one of the bearings and is perpendicular to the shaft, and passes through the other bearing and is perpendicular to the shaft. The rotary drum device is arranged in a region bounded by the second plane. 5. The rotary drum device according to claim 1, 2, 3, or 4, wherein an outer diameter of a rotor portion of the rotary transformer is smaller than an outer diameter of the bearing. 6. The rotor portion of the rotary transformer according to claim 1, wherein an outermost peripheral portion of the rotor portion is machined with reference to a shaft, and a stator portion of the rotary transformer has an innermost portion thereof. A rotary drum device, wherein a peripheral portion is machined on the same axis as a bearing support portion of the shaft support portion of the fixing member. 7. The rotary drum device according to claim 6, wherein the difference between the innermost peripheral diameter of the stator portion of the rotary transformer and the outermost peripheral diameter of the rotor portion is 40 μm or less. 8. The method according to claim 1, 2, 3, 4, 5, 6 or 7.
The rotary drum device according to claim 1, wherein a shaft fitting is fixed to the shaft with a screw, and the rotating member is attached to the shaft fitting.