JPH08250350A - Cylindrical revolution transformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylindrical-type rotary transformer in which windings can be readily inserted into a plurality of grooves formed on rotor coils. SOLUTION: A cylindrical-type rotary transformer 20 is provided with rotor coils 21 having an inside face 21a, a plurality of first annular grooves 23 and a plurality of first windings 25, and stator coils 22 having an outside face 22a, a plurality of second annular grooves 24 and a plurality of second windings 26.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a rotary transformer,
In particular, it relates to a cylindrical rotary transformer in which windings can be easily inserted into a plurality of grooves formed on a rotor coil.

[0002]

BACKGROUND OF THE INVENTION Generally, rotary transformers are used to transfer signals between a rotor and a stator.
It is used to transfer an electrical signal between a rotating drum and a fixed drum of a head drum assembly in a video cassette recorder (VCR).

Usually, this rotary transformer is classified into a flat plate type rotary transformer and a cylindrical type rotary transformer.

FIG. 1 is a sectional view of a conventional flat plate type rotary transformer 1 having a rotor coil 2 and a stator coil 3.

The rotor coil 2 is a rotor body (not shown).
The stator coil 3 is attached to a stator body (not shown), and a plurality of first and second annular grooves 4 and 5 around which a plurality of first and second windings 6 and 7 are wound are provided. Resulting in the formation of multiple channels.

A gap h is formed between the rotor coil 2 and the stator coil 3. An electric signal flowing through any one of the windings 6 and 7 induces an electric signal corresponding to the other coil, so that the electric signal has a gap h.
Is transmitted between the rotating body and the fixed body through.

In such a cylindrical rotary transformer 1,
In order to transmit a constant electric signal without noise, the gap h must always keep a constant distance, which is very difficult.

In order to overcome the drawbacks of the flat plate type rotary transformer, a cylindrical type transformer has been proposed.

FIG. 2 shows a sectional view of a conventional cylindrical rotary transformer 10.

This cylindrical rotary transformer 10 also has a rotor coil 11 and a stator coil 12. The rotor coil 11 is provided with a plurality of first annular grooves 13 into which a plurality of first windings 15 are inserted, and the stator coil 12 has a plurality of second windings 16 on its outer surface. A plurality of second annular grooves 14 to be wound are provided.

The first winding 15 initially has the rotor coil 11
After being wound on a groove having the same depth as the first annular groove 13 on a jig (not shown) having the same outer diameter as the inner diameter of the bottom surface of the first annular groove 13, Is inserted.

However, in such a conventional cylindrical rotary transformer 10, the first annular groove 13 is formed on the inner side surface of the stator coil 11, and each first winding 14 is provided with the corresponding first annular groove. The step of inserting into 13 has a drawback that it is accompanied by great difficulty, the productivity is lowered, and the cost is increased.

[0013]

SUMMARY OF THE INVENTION Accordingly, it is a primary object of the present invention to provide a cylindrical rotary transformer in which windings can be easily inserted into a plurality of grooves formed on a rotor coil.

[0014]

To achieve the above object, according to the present invention, a rotor coil having an inner surface, a plurality of first annular grooves and a plurality of first windings, and an outer surface, a plurality of A cylindrical rotary transformer having a second annular groove and a stator coil having a plurality of second windings, wherein the inner side surface and the outer side surface are inclined so as to be gradually narrowed along a central axis thereof. Are provided to face each other with a predetermined gap, and the first and second annular grooves are formed by axially hollowing out the inner surface and the outer surface, and the cross section thereof is approximately 3 Provided is a cylindrical rotary transformer, which is provided so as to have a rectangular shape, and wherein the first and second windings are fitted and fixed on the first and second annular grooves, respectively. To be done.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will now be described in more detail with reference to the drawings.

FIG. 3 shows a cross-section of a cylindrical rotary transformer 20 according to the present invention. The cylindrical rotary transformer 20 includes a rotor coil 21 and a stator coil 22.

The rotor coil 21 is provided with an inner surface 21a, a plurality of first annular groups 23 and a plurality of first windings 25, and the stator coil 22 is provided with an outer surface 22a, a plurality of second annular grooves 24 and a plurality of second annular grooves 24. Second winding 26 is provided.

The inner side surface 21a and the outer side surface 22a are inclined along the central axis C so as to gradually narrow their intervals upward, and they are opposed to each other with a predetermined gap h.

The first and second annular grooves 23, 24 are formed by hollowing out the inner side surface 21a and the outer side surface 22a in the axial direction, respectively, and are formed so that their cross sections are substantially triangular.

Before being inserted into the first annular groove 23, the first winding 25 is mounted on a jig (not shown) having an outer side surface that is inclined in the same axial direction as the inner side surface 21a of the rotor coil 21. It is wound around the formed grooves. Each of the above grooves corresponds to each of the first annular grooves 23 of the rotor coil 21.

After that, each of the first windings 25 is inserted into the corresponding first annular groove 23 and fixed in the first annular groove 23 using, for example, an adhesive.

On the other hand, each second winding 26 is directly wound in the corresponding second annular groove 24 of the stator coil 22.

The cylindrical rotary transformer 20 of the present invention is a VCR.
Drum in the head drum assembly (not shown)
The rotor coil 21 and the stator coil 22 can be attached to a fixed drum (not shown), respectively.

While specific embodiments of the invention have been described above, it will be apparent to those skilled in the art that various modifications can be made without departing from the scope of the claims set forth in the invention.

[0025]

Therefore, according to the present invention, each first winding can be easily inserted into the corresponding first annular groove, and the first annular groove is formed on the inner surface of the rotor coil. Can be easily provided by simply injection molding.

[Brief description of drawings]

FIG. 1 is a sectional view of a conventional flat plate rotary transformer.

FIG. 2 is a cross-sectional view of a conventional cylindrical rotary transformer.

FIG. 3 is a sectional view of a cylindrical rotary transformer according to the present invention.

[Explanation of symbols]

 1, 10, 20 Cylindrical rotary transformer 2, 11, 21 Rotor coil 3, 12, 22 Stator coil 4, 13, 23 First annular groove 5, 14, 24 Second annular groove 6, 15, 25 First winding Wires 7, 16, 26 Second winding 21a Rotor coil inner side surface 22a Stator coil outer side surface

Claims (2)

[Claims] 1. A rotor coil having an inner surface, a plurality of first annular grooves and a plurality of first windings, and an outer surface, a plurality of second coils.
A cylindrical rotary transformer having an annular groove and a stator coil having a plurality of second windings, wherein the inner side surface and the outer side surface are inclined so as to gradually narrow a distance along a central axis thereof. , Facing each other with a predetermined gap, and the first and second annular grooves are axially gouged in each of the inner side surface and the outer side surface, and the cross section thereof has a substantially triangular shape. The cylindrical rotary transformer is characterized in that the first and second windings are fitted and fixed on the first and second annular grooves, respectively. 2. A head drum assembly for a video cassette recorder, wherein the cylindrical rotary transformer according to claim 1 is incorporated.