JPH01200606A - Rotary transformer apparatus - Google Patents

Abstract

PURPOSE:To make electromagnetic conversion characteristics of an internal peripheral side channel and those of an external peripheral side channel coincide with each other, by making the external peripheral side air gap between a rotary member and a fixed member larger than the internal peripheral side air gap between them. CONSTITUTION:A rotating member 11a unified in a body with a the flange of a rotary side, and a rotating member 11b are fixed by cementing and the like. On the internal peripheral side of the rotating member 11a, a fixed member 14 attached to a flange 4 on the fixing side is provided. Between the rotary member 11a and the fixed member 14, an air gap 12a is kept. On the external peripheral side of a rotary member 11b, a fixed member 13 attached to the flange 4 on the fixing side is provided. Between the rotary member 11b and the fixed member 13, an air gap 12b is kept. In this case, the width B of the air gap 12b is made larger than the width A of the air gap 12a. As a result, the difference of facing areas of the rotary members 11a, 11b and the fixed members 13, 14 between the internal peripheral side and the external peripheral side is relieved. Thereby electromagnetic conversion characteristics of internal peripheral side channel and that of external peripheral side channel can be made to coincide with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a rotary transformer device used for signal coupling between a rotary magnetic head and an external circuit in a rotary head type magnetic recording/reproducing device.

(Prior Art) In recent years, high-density recording has progressed in VTRs, and it has become difficult to perform recording and reproduction using a single head, so signals have been recorded in parts using a plurality of heads. On the other hand, in order to transmit signals between the rotating side and the stationary side, a rotating transformer device as shown in Figures 4 and 5 is used, but as the number of heads increases, multiple rotating transformers are also used. I needed a channel. The coaxial rotary transformer device shown in Fig. 4 is a two-channel type, with a rotating side flange 2 on shaft 1.
A rotating member 3 held by adhesive or the like is attached to the rotating member 3, and a gap 6 exists between the rotating member 3 and the fixed member 5 held by the fixed flange 4. Channel A core 7 and channel B core 8 overlap in the axis 1 direction, and a short ring 9 is provided between channel A core 7 and channel B core 8 to prevent crosstalk. A coil 10 is wound around the channel A core 7 and the channel B core 8. The two-channel flat plate rotary transformer shown in Fig. 5 has a channel A core 7 and a channel B core 8 in the circumferential direction.
are arranged, and the other configurations are equivalent to those described above.

However, these rotary transformer devices have the disadvantage that as the number of channels increases, the coaxial rotary transformer device shown in FIG. 4 extends in the axial direction and becomes larger overall.

Further, in the flat plate type rotary transformer device shown in FIG. 5, since the opposing areas of the cores of the inner channel and the outer channel are different, there is a problem in that the electromagnetic conversion characteristics of each channel are different.

As a means of solving the problem of increasing the size of the above-mentioned coaxial rotary transformer device, as shown in FIG.
A so-called double coaxial rotary transformer device has been proposed. A rotating member 11 integrated into the rotating side flange 2
a and the rotating member 11b are attached by adhesive etc., and the rotating member 1
A fixed member 14 is provided on the inner peripheral side of 1a, and a gap 12a is secured between the rotating member 11a and the fixed member 14. There is a fixed member 13 on the outer peripheral side of the rotating member 11b, and the fixed member 13 and the fixed member 14 are attached to the flange 4 on the fixed side so that a gap 12b is secured between the rotating member 11b and the fixed member 13. ing. Here, the width A of the void 12a and the width B of the void 12b are the same. However, if a double coaxial rotary transformer is used, the number of channels can be increased without increasing the size. Since the areas facing the cores differ, a problem arises in that the electromagnetic conversion characteristics of the channels on the inner circumferential side and the channels on the outer circumferential side differ.

In addition, in the flat plate rotary transformer device shown in Fig. 5, the engagement coefficient is matched with that on the inner circumference by reducing the opposing area and reducing the inductance by reducing the land width of the channel on the outer circumference. A method was also taken.

However, in this method, as the number of channels increases, the land width on the outer circumferential side becomes extremely small, which is not desirable in terms of processing or strength, and as a result, the number of channels is limited.

(Problems to be Solved by the Invention) As described above, when trying to transmit multi-channel signals using a conventional double coaxial rotary transformer device or a flat plate rotary transformer device, the inner channel and the outer channel There was a problem that differences occurred in the electromagnetic conversion characteristics of the channels.

The present invention has been made in view of the above circumstances, and its purpose is to provide a rotary transformer device in which the electromagnetic conversion characteristics of the inner channel and the outer channel of the rotary transformer device match. be.

[Structure of the invention]

(Means for Solving the Problems) According to the present invention, in a rotating transformer device that transmits signals in a non-contact manner between a rotating member and a fixed member attached with a predetermined gap, The gap on the side is made larger than the gap on the inner circumferential side.

(Function) In the device configured in this way, the leakage magnetic flux is large on the outer circumference side where the gap is large, and the leakage magnetic flux is small on the inner circumference side where the gap is small. Moreover, the opposing area is large on the outer circumferential side, and the opposing area is small on the inner circumferential side. By appropriately setting the magnitude relationship of the leakage magnetic flux and the magnitude relationship of the facing area, the transmission characteristics (electromagnetic conversion characteristics or coupling coefficient) can be made equal for each channel on the inner circumferential side and the outer circumferential side.

(Example) The present invention will be described in detail below with reference to one drawing.

FIG. 1 is a sectional view showing a double coaxial rotary transformer device according to an embodiment of the present invention. In the same figure, a rotating member 11a and a rotating member 1 integrated with the rotating flange 2 are shown.
1b is attached by adhesive or the like, and there is a fixing member 14 attached to the fixed flange 4 on the inner peripheral side of the rotating member 11a, and a gap 12a is formed between the rotating member 11a and the fixing member 14.
is ensured. There is a fixed member 13 attached to the fixed flange 4 on the outer peripheral side of the rotating member 11b, and a gap 12b is secured between the rotating member 11b and the fixed member 13. In the present invention, the gap B between the gaps 12b is larger than the width A of the gap 12a, and the rotating member 11
a, 6th-order 2nd half, which is configured to alleviate the difference in the facing area between Ilb and the fixing member 13. The figure shows another embodiment of the present invention, and is a sectional view showing a flat plate rotary transformer device.

In FIG. 2, in the gap 6 between the fixed member 5 and the rotating member 3, the gap in the outer channel core 8 (indicated as B) is made larger than the gap in the inner channel core 7 (indicated as A). As a result, the leakage flux in the outer channel becomes larger than that in the inner channel, and the coupling coefficient of the outer channel can be made equal to the coupling coefficient of the inner channel, which improves the transmission characteristics (electromagnetic conversion characteristics) of each channel. can be made uniform. Furthermore, as the number of channels increases, the rotating transformer becomes larger and it becomes difficult to set the rotating member 3 and the fixed member 5 with a minute gap of several tens of microseconds, but it is difficult to set the rotating member 3 and the fixed member 5 with a minute gap of several tens of microseconds. With this structure, even if the rotating member 3 and the fixed member 5 are not parallel to each other during assembly and are slightly inclined, the rotating member 3 and the fixed member 5 will come into contact because the gap is large on the outer circumferential side. It also has the advantage of being easy to assemble and eliminates problems.

Further, in FIG. 2, a two-channel rotary transformer is explained for the sake of simplicity. However, it is of course applicable to rotations having a larger number of channels. Third
As shown in the figure, when the number of channels increases, certain channels (channels 21, 22 on the inner circumference side in Figure 3)
．． Up to 23), the method of changing the facing area (land width) is used, and for the outer peripheral channel where the land width is smaller than a certain value (24.25 in Figure 3), the method of changing the air gap is used. It is also possible to take

In addition to this, various modifications and implementations are possible.

In addition, although these examples show cases where the air gap is changed by machining either the rotating side core or the stationary side core of the rotary transformer, it is also possible to change the air gap by machining both transformers. good.

〔Effect of the invention〕

As detailed above, in the present invention, the electromagnetic conversion characteristics of the inner channel and the outer channel can be matched by making the gap between the rotating member and the fixed member wider on the outer circumferential side than on the inner circumferential side. .

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of a rotary transformer device of the present invention, FIG. 2 is a cross-sectional view of another embodiment of the present invention,
3 is a sectional view of a modification of the present invention, FIG. 4 is a sectional view of a conventional coaxial rotary transformer device, FIG. 5 is a sectional view of a conventional flat plate rotary transformer device, and FIG. 6 is a sectional view of a conventional coaxial rotary transformer device. 1 is a sectional view of a conventional double coaxial rotary transformer device. 1... Shaft 2... Rotating shaft flange 3
...Rotating member 4...Fixed side flange 5.
...Fixing member 6...Gap 7...A channel core 8...B channel core 9...Short ring 10...Coil 11a...
...Rotating member 11b on the inner circumferential side...Rotating member 12a on the outer circumferential side...Gap on the inner circumferential side 12b...Gap on the outer circumferential side 13...Fixing member on the outer circumferential side 14...Inner circumferential side Fixing member A...Gap width on the inner circumference side B...Gap width on the outer circumference side Agent Patent attorney Noriyuki Chika Mitsuyuki Matsuyama / Zb /Zα /4 Figure 1 B 2 Figure 4

Claims (1)

[Claims] In a rotating transformer device that performs non-contact signal transmission between a rotating member and a fixed member installed with a predetermined gap therebetween, the gap on the outer circumferential side with respect to the center of rotation is defined as the gap on the inner circumferential side. A rotating transformer device characterized by being larger than.