JPS62291011A - Rotary transformer - Google Patents

Abstract

PURPOSE:To obtain a rotary transformer which is a thin shape, and lightweight, which requires no polishing finish and which can be manufactured efficiently by providing a magnetic film coated on a flexible material thin sheet for at least one magnetic material and a base material for supporting the thin sheet. CONSTITUTION:In a rotary transformer consisting of as pair of magnetic materials facing each other in the direction of a plane or a circumference with a gap and a pair or more of conductors provided between the faces of the magnetic materials, at least one magnetic mateiral consists of a magnetic film 13 coated on a flexible material thin sheet 12 and a base material 11 which supports the thin sheet 12. For example, Ring grooves 17a, 17b for winding are formed respectively on the surfaces facing each other with a minute gap of a rotary side base material 11a and a fixed side base material 11b. The magnetic film 13 is formed on one surface of the flexible material thin sheet 12 and a conductive film 14 is formed on the other surface. The thin sheet 12 is so provided as to cover at least the sides on which the grooves 17 for winding are formed of the above-mentioned base materials 11a, 11b.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention Industrial Application Field The present invention relates to a rotary transformer used in a magnetic recording/reproducing device having a rotating magnetic head and for transmitting signals between a rotating head section and a fixed section. It is related to.

BACKGROUND OF THE INVENTION In recent years, rotating head type magnetic recording and reproducing apparatuses using rotating transformers have been made smaller, lighter, and lower in cost.

For this reason, the development of a manufacturing method that can realize the rotary transformer, which is one of the components, efficiently and at low cost is underway from the viewpoints of reducing the size and weight of the rotary transformer as well as mass production.

Hereinafter, an example of the conventional rotary transformer described above will be explained with reference to the drawings.

FIG. 3 is a sectional view of a conventional planar rotary transformer. The rotating side annular core 3a (hereinafter referred to as R core) attached to the rotating side base material 1a and the fixed side annular core 3b (hereinafter referred to as S core) attached to the fixed side base material 1b are made of sintered ferrite with low high frequency loss. It is made with a polished finish on both sides. Winding grooves 7a and 7b are formed in an annular shape on the opposing surfaces of the R core 3a and the S core 3b, respectively, and the rotating side coil 5a (hereinafter referred to as "winding grooves") wound around one to several turns is formed in the rotating side winding 7117a. Similarly, the fixed side coil 5b (hereinafter referred to as S coil) is fixed to the fixed side winding a7b according to the predetermined step-up ratio with respect to the number of turns of the R':J coil 5a. It is wound by the same number of turns and similarly fixed with adhesive 8. In addition, R core 3a
and S core 3b face each other with a minute gap of several tens of micrometers, forming a magnetic path 9 as shown by a dotted line. When current flows through the R coil 5a, the S coil 5b is caused by mutual induction.
A current is induced and a signal is transmitted. The same applies when a signal is transmitted from the S coil 5b to the R coil 5a.

(For example, Saka 1) Minoru, Takashi Kuninaka "Rotating transformer", National Technical Report vol. 1.18. No, 4
．． 1972, P359-p369).

Problems to be Solved by the Invention However, in the above configuration, the R core 3a and S core 3b, which are the main parts, are manufactured by sintering ferrite powder, so the wall thickness is about IN. This was the limit, and was an obstacle to making the product thinner and lighter. Also,
Sintered ferrite, which has poor workability, requires polishing and finishing to improve the dimensional accuracy, which has been a factor in increasing costs.

In view of the above problems, the present invention provides a rotary transformer that is thin, lightweight, does not require polishing and finishing, and can be manufactured efficiently.

Means for Solving the Problems In order to solve the above problems, the rotating transformer of the present invention has the following features:
In a rotary transformer comprising a pair of magnetic bodies facing each other in the plane or circumferential direction with a certain gap, and at least one pair of conductors disposed within the opposing surfaces of the pair of magnetic bodies, at least one of the above-mentioned The magnetic body includes a magnetic film coated on a thin sheet made of a flexible material, and a base material that supports the thin sheet.

Function The present invention has the above-described structure, by separately processing a base material that is easy to process and achieving precision, and manufacturing a thin sheet made of a flexible material to which a magnetic film is attached, and then combining the two. , the rotary transformer can be made thinner, lighter, and lower in cost.

Examples Below, regarding the rotary transformer of the first embodiment of the present invention,
This will be explained with reference to the drawings.

FIG. 1 shows a sectional view of a rotary transformer in an embodiment of the present invention. In FIG. 1, the rotating side base material 11
a and the fixed side base material 11b face each other with a small gap of several tens of micrometers (hereinafter, the "rotating side" will be abbreviated as "R side" and the "fixed side" will be abbreviated as "S side"). S side, R side base materials 11a, l
An annular groove, an R-side winding groove 17a and an S-side winding groove 17b, is formed on each opposing surface side of the lb. Base material 1
1a.

The material of the member 11b can be selected from metals, resins, etc., which facilitates machining accuracy of the opposing surfaces. In particular, if resin is used, injection molding can be used, the cost is low, and the specific gravity is small, so it is possible to reduce the weight of the rotary transformer. Further, a magnetic film 13 with a thickness Tm is formed on one surface of a thin sheet 12 made of a flexible material and a thickness Tb, and a conductive film 14 with a thickness Tc is formed on the other surface. Here, the thickness Tm of the magnetic film 13 depends on the magnetic permeability of the magnetic material, but the material is Sendust or Permalloy used for magnetic recording.

If a material such as ferrite is used for signal transmission up to several MHz, a thickness of about 10 μm to several tens of μm is sufficient. Further, during manufacture, the magnetic film 13 is formed by adhering materials such as sendust, permalloy, ferrite, etc. to the thin sheet 12 in molecules such as sputtering or in liquid form such as coating. Further, the thickness Tc of the conductive film 14 depends on the conductivity, but in the case of copper or the like used as a conductor, a thickness of about 10 μm to several tens of μm is sufficient. Further, during manufacturing, the conductive film 14 is formed by adhering a conductive material such as copper to the thin sheet 12 in the form of molecules or liquid. And the R side and S side base materials 11a, l
A thin sheet 12 is attached to cover at least the side where the winding groove is formed. Since the material of the thin sheet 12 is a flexible material, it has excellent flexibility and can easily follow the R-side and S-side base materials 11a and 11b, which are finished with high precision, making it easy to achieve the accuracy of the thin sheet 12 itself. Further, a resin-based flexible material has excellent non-magnetic properties and insulation properties.

Now, in this embodiment, a case will be considered in which a signal is transmitted from the R side to the S side. When a current flows through the R-side conductive film 15a, the generated magnetic flux follows a magnetic path 19 as indicated by a dotted line along the magnetic film 13.
A current is induced in the fixed conductive film 15b through the fixed side conductive film 15b, and a signal is transmitted. According to the present invention, the thickness of the magnetic film 13 can be reduced, so that it can be made thinner and lighter. In addition, it is possible to process the base material 11 by freely selecting a material that is easy to process and has high precision without requiring polishing of the sintered ferrite material, which increases processing costs, thereby reducing costs. be able to. Furthermore, since it is possible to process the base material 11 and manufacture the thin sheet 12 made of a flexible material on which the magnetic film 14 is attached and then combine the two separately, the cost can be reduced. be able to.

FIG. 2 is a sectional view of a rotary transformer according to another embodiment of the present invention, in which a conductive film 14 is deposited on the surface of the magnetic film 13 so as to form a magnetic circuit. In the case of this embodiment, if the thickness Tb of the thin material, the thickness Tm of the magnetic film, and the thickness Tc of the conductive film are made equivalent to those of the first embodiment, the distance Tv between the magnetic films can be shortened, so that the transmission efficiency can be improved. can be raised.

In the embodiments described above, both the rotating side and the stationary side have the configuration of the present invention, but it goes without saying that one may have the configuration of the present invention and the other may have the conventional configuration. Further, in the embodiments described above, a planar rotary transformer has been described, but a cylindrical rotary transformer can be similarly configured.

Effects of the Invention As described above, the present invention is composed of a pair of magnetic bodies facing each other in the plane or circumferential direction with a certain gap, and one or more pairs of conductors disposed within the opposing planes of the pair of magnetic bodies. In the rotary transformer, at least one of the magnetic bodies is a thin sheet made of a flexible material and a magnetic film coated on the thin sheet, and a base material supporting the thin sheet described in -F is provided, thereby making the rotary transformer thin, lightweight, Cost reduction can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a rotary transformer according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of a rotary transformer according to another embodiment of the present invention, and FIG. 3 is a cross-sectional view of a conventional rotary transformer. 11... Base material, 12... Thin wall material, 13
...Magnetic film, 14... Conductive film, 17.
...Winding groove, 19...Magnetic path, ■...
... Base material, 3 ... Annular core, 5 ... Coil, 7 ... Winding groove, 8 ... Adhesive,
9...Magnetic path. Name of agent: Patent attorney Toshio Nakao
Rotating side group, family A1b-゛-rotation11ri j2--mi'gJ-zuJC1. I3)

Claims (2)

[Claims] (1) In a rotating transformer consisting of a pair of magnetic bodies that face each other in a plane or circumferential direction with a certain gap in between, and one or more pairs of conductors disposed within the opposing surfaces of the pair of magnetic bodies, at least one A rotary transformer characterized in that the magnetic body is composed of a magnetic film coated on a thin sheet made of a flexible material, and a base material supporting the thin sheet. (2) The rotary transformer according to claim (1), wherein at least one conductor is formed on the magnetic material or on the opposite surface of the thin sheet coated with the magnetic film.