JPH01189108A - Rotary transformer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is used in a magnetic recording/reproducing device having a rotating magnetic head such as a video tape recorder or a digital audio tape recorder, and is used for signal transmission between a rotating head section and a fixed circuit section. This study concerns the miniaturization of rotating transformers and crosstalk.

2. Description of the Related Art In recent years, rotary head type magnetic recording and reproducing devices using rotary transformers have been made smaller and more sophisticated. Therefore, even in the rotating transformer, which is one of the components and has a plurality of channels, there is a demand for miniaturization and extremely low signal crosstalk between channels during recording and reproduction.

An example of the conventional rotary transformer mentioned above will be described below with reference to the drawings.

FIG. 3 shows a sectional view of a circumferentially opposed rotary transformer for 6 channels in a conventional embodiment, and FIG. 4 shows a sectional view of a surface-contained rotary transformer for 6 channels in a conventional embodiment. It is.

In FIG. 3, an annular first magnetic body 1a on the rotating side
In FIG. 4, both end surfaces of the first magnetic body 1a face two annular second magnetic bodies 1b on the fixed side with a gap of several tens of μm. The first magnetic body 1a and the second magnetic body 1b are made of N, which has low high frequency loss.
It is made by sintering i-Zn ferrite or Mn-Zn ferrite, and has a polished finish on both sides.

Here, in the circumferentially opposed type shown in FIG. 3, the first magnetic body 1a
In the surface facing type shown in FIG. 4, annular winding grooves 4a are provided in a staggered manner on both end surfaces of the first magnetic body 1a.
An annular winding groove 4b is also formed in each of the two second magnetic bodies 1b, facing the winding groove 4a. Each of the winding grooves 4a of the first magnetic body 1a has one to
First coils 21a to 26a wound around several turns are disposed, and similarly, second coils 21b to 26b are arranged in the winding groove 4b of the second magnetic body 1b.
For the number of turns 1a to 26a, the number of turns corresponds to a predetermined boost ratio.

Here, for example, when a signal current flows through the first coil 22a, a magnetic path C1-C5 is formed. Then, a current is induced in the second coil 22b due to mutual induction, and a signal is transmitted. Here, the short ring 8 disposed in the short ring groove 9 is formed of a short-circuited conductive material, and for example, the magnetic flux density with respect to time of the magnetic path C3 that occurs when a current flows through the first coil 22a. By utilizing the change in the short ring 8 to generate an eddy current, the magnetic flux in the magnetic path C3 is reduced as a result. this'
By utilizing this phenomenon, it is possible to reduce the current transmitted to the other coils, in the case of the above example, the second coils 24b and 25b, thereby improving crosstalk. For example, Minoru Sakata, Takashi Tanaka "Rotating transformer", National Technical Report vol.
, 18. Nn 4.1972゜p359-p36
9).

Problems to be Solved by the Invention However, in the above configuration, the first magnetic body 1a and the second magnetic body 1b are made of brittle Ni-Zn.
It is made by sintering ferrite or Mn-Zn ferrite, and must be machined by polishing to improve surface precision. Thickness dl or more,
d2, and there was a problem that it could not be made smaller. Furthermore, for example, regarding the magnetic path C2 that is formed when a signal current flows through the first coil 22a, the effect of the short ring 8 cannot be expected, and there is also the problem that crosstalk cannot be reduced beyond a certain level. .

In view of the above-mentioned problems, the present invention provides a rotary transformer that can be miniaturized and reduce crosstalk when multiple channels are required.

Means for Solving the Problems In order to solve the above problems, the rotary transformer of the present invention includes a first base member having an annular shape, and an inner and outer periphery of the first base member facing each other with a predetermined gap therebetween. Alternatively, an annular second base material faces both end faces of the first base material with a predetermined gap therebetween, and one of the first base material and the second base material is a fixed side and the other is a fixed side. on the rotating side, and when the first base material is circumferentially opposed to the second base material, the first base material
When the first base material is face-to-face with the second base material, the first base material a first magnetic film divided concentrically at a predetermined distance in the radial direction on both end faces of the material, and disposed on the first magnetic film facing the second base material, respectively; The first base material includes a first coil that is concentric with the first base material, a second magnetic film that is concentrically divided and formed on the second base material so as to face the first magnetic film, and a second magnetic film that is concentrically formed on the second base material, and 1st
a second coil, which is disposed on the second magnetic film facing the magnetic film, and which is concentric with the second base material; At least the surfaces of the first base material and the second base material on which the surface is formed are made of a conductive material or a superconducting material.

Function: With the above-described configuration, the present invention can realize miniaturization in the thickness direction by making the magnetic material forming the magnetic path thinner. In addition, by forming the magnetic film separately for each coil and using a conductive material or a superconducting material for the base material on which the magnetic film is formed, crosstalk can be extremely reduced and at the same time Miniaturization can be achieved.

EXAMPLE A rotary transformer according to a first example of the present invention will be described below with reference to the drawings.

FIG. 1 shows a sectional view of a circumferentially opposed rotary transformer for six channels in a first embodiment of the present invention. In addition, the thin film portion is exaggerated in the figure, and some parts common to the configuration described in the conventional example are omitted. The inner and outer circumferential surfaces of the first base material 5a, which is annular on the rotating side and made of a conductive material or a superconducting material, have a gap of several tens of μm between the two annular base materials on the stationary side, which are also made of a conductive material or a superconducting material. It faces the base material 5b of No. 2 in the circumferential direction. Here, first magnetic films 31a to 36a are formed concentrically on the inner and outer circumferential surfaces of the first base material 5a by means of coating, vapor deposition, etc. by dividing them in the axial direction.
A first coil 2 is disposed on each of the magnetic films 31a to 36a.
13 to 26a are arranged.

Further, on the second base material 5b, first magnetic films 313 to 36 are provided.
The second magnetic films 31b to 36b are concentrically divided and formed so as to face the second magnetic films 31b to 36b.
Second coils 21b to 26b are arranged on the coil 6b.

Now, in this embodiment, the first base material 5a and the second base material 5a
It is not necessary to use a mechanically brittle ferrite-based magnetic material for the base material 5b, and a conductive metal material such as copper or aluminum can be used to increase the toughness. can. Therefore, the wall thickness can be made thinner than when using a sintered magnetic material, and the rotary transformer can be made smaller in the radial direction. Next, for example, when a signal current is passed through the first coil 22a, magnetic paths C1 to C3 are formed.
Since the magnetic films 1a to 36a and the second magnetic films 31b to 36b are formed separately, the magnetic flux flowing in the magnetic paths C2 and C3 can be reduced. At the same time, since the first base material 5a and the second base material 5b are made of a conductive material or a superconducting material, eddy currents are generated in the magnetic paths C2 and C3, resulting in magnetic The magnetic flux flowing through the paths C2 and C3 can be extremely reduced, and crosstalk can be reduced.

Furthermore, since the first base material 5a and the second base material 5b are made of a conductive material or a superconducting material, they also have the function of a short ring, thereby securing a space for arranging the short ring. Since this is not necessary, the rotary transformer can be downsized in the axial direction. Here, superconducting materials can reduce high frequency loss compared to conductive materials.

A second embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows a sectional view of a six-channel surface-facing rotary transformer according to a second embodiment of the present invention. Note that common parts in the configuration described in the first embodiment will be omitted. Both end surfaces of the rotating-side annular first base material 5a made of a conductive material face two annular fixed-side second base materials 5b made of a conductive material with a gap of several tens of micrometers in the surface direction. are doing. Here, first magnetic films 313 to 36a are formed on both end surfaces of the first base material 5a, respectively, in the radial direction and in a staggered manner with respect to both end surfaces.

Here, since the winding grooves 4a are formed in a staggered manner, the thickness of the first base material 5a is such that the winding grooves described in the first embodiment are opposite to both end surfaces of the first base material. Since the rotary transformer can be made even thinner than the conventional rotary transformer, the rotary transformer can be made smaller.

In addition, in the embodiments described above, the first base material and the second base material
All of the base materials are made of conductive material or superconducting material, but the surfaces of the first base material and the second base material on the side where the magnetic film is formed are made of conductive material or superconducting material. It may be made of any material. Furthermore, in the embodiments described above, the first base material is the rotating side and the second base material is the fixed side, but the first base material may be the fixed side and the second base material is the rotating side. Needless to say.

Furthermore, the superconducting material in the above embodiments may be, for example, a so-called room-temperature superconductor, or a material whose superconducting critical temperature is between room temperature and the boiling point of liquid nitrogen and cooled with liquid nitrogen (Fig. (not shown), or a material with a superconducting critical temperature below the boiling point of liquid nitrogen may be used and cooled with liquid helium (not shown). An example of a room-temperature superconductor is a ceramic oxide containing strontium (Sr), barium (Ba), yttrium (Y), and copper (Cu) in a ratio of 1:113. As an example of the manufacturing method, S r
A predetermined amount of powders of Cox, Ba Cox, Y203, and CuO were mixed, pulverized, and heated to 92% in air.
Bake at 0°C for 5 hours. This firing and crushing process is repeated three times to improve homogeneity. After cold compression molding the mixed powder treated in this way, it is produced by firing in air at 1000° C. for 5 hours and slowly cooling.

Effects of the Invention As described above, the present invention provides an annular first base material that faces the inner and outer peripheries of the first base material with a predetermined gap, or both ends of the first base material. an annular second base material facing the surface with a predetermined gap therebetween;
One of the first base material and the second base material is a fixed side and the other is a rotating side, and when the first base material is circumferentially opposed to the second base material, the first base material The first part is formed concentrically divided at a predetermined distance in the axial direction on the inner and outer circumferential surfaces of the base material.
When the base material is face-to-face with the second base material, a first magnetic film is formed concentrically and divided at a predetermined distance in the radial direction on both end faces of the first base material. , respectively disposed on the first magnetic film facing the second base material, and
The base material includes a concentric first coil, a second magnetic film concentrically divided and formed on the second base material so as to face the first magnetic film, and the first magnetic film. a second coil disposed on the second magnetic film facing the magnetic film and concentric with the second base material; By using a conductive material or a superconducting material on the surface of the first base material and the second base material on the side where it is formed, it is possible to reduce the size of the rotating transformer and reduce crosstalk. can be extremely reduced.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a circumference-facing rotary transformer according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view of a surface-facing rotary transformer according to a second embodiment of the present invention, and FIG. FIG. 4 is a cross-sectional view of a circumference-facing rotary transformer according to an embodiment of the present invention. FIG. 4 is a cross-sectional view of a surface-facing rotary transformer according to a conventional embodiment. l...magnetic material, 21-26...coil, 31-36...magnetic film, 4...winding groove, 5...・Base material, 8... Seayot ring, 9... Short ring groove. Name of agent: Patent attorney Toshio Nakao 1 person 4-2-Weizhugou Figure 1 5-Base material 21~? 6-Coil Diagram 2 No-Road End Diagram 4

Claims (2)

[Claims] (1) A first base material having an annular shape faces the inner and outer peripheries of the first base material with a predetermined gap therebetween, or faces both end faces of the first base material with a predetermined gap therebetween. An annular second base material facing each other, one of the first base material and the second base material is a fixed side and the other is a rotating side, and the first base material is the second base material. When facing Zhou,
The first base material is divided concentrically at a predetermined distance in the axial direction on the inner and outer circumferential surfaces of the first base material, and the first base material is formed on the inner and outer circumferential surfaces of the second base material.
When facing the base material, a first magnetic film is formed by dividing concentrically at a predetermined distance in the radial direction on both end faces of the first base material, and a first magnetic film is formed on both end faces of the first base material, and A first coil is disposed on the first magnetic film facing the first magnetic film and is concentric with the first base material, and a first coil is disposed on the second base material facing the first magnetic film. a second magnetic film divided and formed concentrically, and a second magnetic film facing the first magnetic film, respectively disposed on the second magnetic film, and a second magnetic film concentric with the second base material. and at least the surfaces of the first base material and the second base material on the side on which the first magnetic film or the second magnetic film is formed are made of a conductive material or a superconducting material. A rotating transformer characterized by: (2) When the first base material is circumferentially opposed to the second base material, the first magnetic body provided separately on the first base material is staggered alternately on the inner and outer circumferences in the axial direction. Claims characterized in that the first base material is formed in a zigzag shape, and when the first base material faces the second base material, both end faces are alternately formed in a staggered manner in the radial direction. The rotating transformer described in paragraph (1).