JPH09275027A - Rotary transformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary transformer without the increase of split or crack generated in a core. SOLUTION: A rotary transformer includes a stator core 5, a rotor core, and coil storing grooves 7 and 9 opposite to each core. Block cores 12a and 12b are provided at a circumferential end 5a and/or an inner circumferential edge 5b of the stator core 5 and/or the rotor core so that the increase of splits 10a and 10b or cracks 11a and 11b can be limited to an area of block cores 12a and 12b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary transformer used for transmitting signals between a rotor portion and a stator portion used in a magnetic recording device or the like.

[Prior art]

In a magnetic recording / reproducing apparatus, such as a magnetic recording apparatus (VTR), which records or reproduces a signal on a magnetic medium in a state where the magnetic head is constantly rotating, a rotating magnetic head and a peripheral circuit are provided. A rotary transformer is used to send and receive signals between the two.

FIG. 7 is a sectional view showing a schematic structure of a rotary transformer. A rotary transformer 1 is composed of a rotor portion 2 and a stator portion 3, and each has a disk-shaped core 4 or 5.
Are arranged facing each other. An example of transmitting and receiving signals of two channels will be described. One channel coil 6a is provided in each of the concentric coil grooves 6 and 7 provided in each core 4 and 5.
And 7a are wound and the inner concentric coil groove 8 is also formed.
Two-channel coils 8a and 9a are wound around and 9, respectively.

Ferrite is usually used as a constituent material for the cores 4 and 5 of the rotary transformer 1. Ferrite has excellent magnetic properties, but it is well known that it is very brittle. I am here. Therefore, when the rotary transformer 1 is assembled or during transportation or the like, an external force due to contact between the cores is applied, and the outer peripheral portions of the cores 4 and 5 are likely to be chipped or cracked.

For example, in the perspective view of the core shown in FIG. 8A and the partial sectional view of the core shown in FIG. 8B, one chip 10a extends from the outer peripheral edge 5a of the core 5 to the outer coil groove 7, The other chip 10b extends from the inner peripheral edge 5b of the core 5 to the inner coil groove 9.

On the other hand, one crack 11a extends from the outer peripheral edge 5a of the core 5 to the outer coil groove 7, and the other chip 11b extends from the inner peripheral edge 5b of the core to the inner coil groove 9.

Such chipping or cracking in the core causes a reduction in the inductance, which is the most important characteristic of the rotary transformer, and makes it unusable, so it must be avoided as much as possible.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a rotary transformer capable of suppressing the increase of cracks and cracks that tend to occur in the core of a rotary transformer.

[0009]

In order to solve the above-mentioned problems, a rotary transformer according to a first aspect of the present invention is a rotary transformer having a stator core and a rotor core, and a coil housing groove provided on an opposing surface of the core. Alternatively, block cores are provided at the outer peripheral edge and / or the inner peripheral edge of the rotor core so as to suppress cracking and crack growth, thereby forming a rotary transformer, and the cracks are stopped within the range of the block core.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a rotary transformer of the present invention will be described below with reference to FIGS. First Embodiment Example FIG. 1 is a perspective view of a core of a flat plate type rotary transformer according to the present invention before assembly.

In FIG. 1, the outer peripheral edge 5a of the lower core 5 is shown.
The ring-shaped block core 12a is provided between the coil storage groove 7 and the coil storage groove 7, and the block core 12b is also provided between the inner peripheral edge 5b and the coil storage groove 9. Block core 12
The a and 12b are molded separately from the core 5, and are adhered with an appropriate adhesive, and then polished and shaped. With this configuration, for example, when the chip 10a occurs on the outer periphery as shown in the cross-sectional view of the perspective view of FIG. 2A and the cross-sectional view of FIG.
Although a tends to increase to the inside of the core 5, it stops within the range of the block core 12a and does not reach the coil housing groove 7.

Similarly, the chip 11b formed on the inner peripheral edge 5b is prevented from remaining in the area of the block core 12b and reaching the coil housing groove 9. Also, crack 11
When a and 11b occur, stop the growth in the same way,
It prevents them from reaching the coil housing grooves 12a, 12b.

Second Embodiment Example FIG. 3 is a perspective view of a rotary transformer according to a second embodiment example of the present invention. In the figure, a plurality of ring-shaped block cores are arranged in the circumferential direction, in this example, six block cores 12a1, 12a2, 12a3, 12a4, 12a.
It is divided into 5 and 12a6. With this configuration, it is possible to suppress the cracks and cracks from increasing in the circumferential direction.

Third Embodiment FIG. 4A is a side sectional view of a rotary transformer according to a third embodiment of the present invention. In the third embodiment, a block core is used. It is divided into a plurality of pieces in the diametrical direction, and (a) shows block cores 12c1, 12c2, 12 at each edge of the outer peripheral edge 5a, the coil receiving grooves 7, 9, and the inner peripheral edge 5b.
It was divided into c3, 12c4, 12c5 and 12c6. With this configuration, it is possible to stop the cracks and cracks from increasing in diameter in a narrower range.

In FIG. 4B, the division is further finely divided into 12 parts 12c11 from the outer peripheral edge 5a portion to the inner peripheral edge 5b.
12c12, 12c21, 12c22, 12c31, 12c32,
12c41, 12c42, 12c511, 12c52, 12c6
1 and 12c62. In addition, FIG.
This is an example in which all the surface portions of are divided.

Fourth Embodiment FIG. 5 is a perspective view of a rotary transformer according to a fourth embodiment of the present invention. The fourth embodiment is a cylindrical rotary transformer. It is an example of carrying out the invention.
The inside is the rotor portion 22, the outside is the stator portion 23,
Each of them is formed of a cylindrical core 25, 24, and they are concentrically combined.

The core 24 of the rotor portion 22 is provided with coil storage grooves 26 and 28 for storing the coils of the respective channels, and in the present invention, the upper end portion 24a and the lower end portion 24b thereof are provided.
The block cores 32a and 32b are provided in a ring shape.

Further, the core 25 of the stator portion 23 has coil housing grooves 27 and 29 for housing coils of respective channels.
Are provided above and below, and in the present invention, block cores 42a and 42b are provided in a ring shape at the upper end portion 25a and the lower end portion 25b.

With this configuration, the chippings and cracks generated at the upper end portions 24a, 25a and the lower end portions 24a, 15b of the respective cores 24, 25 are blocked by the block cores 32a, 32b, 42.
It remains within the range of a and 42b, and further growth is suppressed.

FIG. 6 shows the sectional shapes of the divided blocks of each of the above-described embodiments. (A) is a rectangle, (c) is a triangle, (c) is a quadrant, and (d) is an L-shape. , (E) are examples of pentagons, and an appropriate shape can be selected as necessary.

[0021]

As described above, according to the rotary transformer of the present invention, it is possible to provide a rotary transformer capable of suppressing the chipping and crack growth of the core.

[Brief description of drawings]

FIG. 1 is a perspective view of a stator core of a flat plate type rotary transformer of the present invention before assembly.

FIG. 2 shows a stator core of a flat plate type rotary transformer of the present invention, (a) is a perspective view and (b) is a sectional view.

FIG. 3 is a perspective view before assembling of a stator core of a flat plate type rotary transformer according to a second embodiment of the present invention.

FIG. 4 is a side sectional view of a flat plate type rotary transformer of the present invention. (A) is a block core divided into four, (b),
(C) is an example of 12 divisions.

FIG. 5 is a perspective view of a cylindrical rotary transformer according to a third embodiment of the present invention before assembly.

FIG. 6 is a perspective view of the core of the rotary transformer of the present invention before assembly, showing the cross-sectional shapes of the block core: (a) is a rectangle, (b) is a triangle, (c) is a quadrant, and (d) is. L-shaped, (d) is an example of a pentagon.

FIG. 7 is a side sectional view of a general flat plate type rotary transformer.

FIG. 8 shows a conventional flat plate type rotary transformer,
(A) is a perspective view and (b) is a side sectional view.

[Explanation of symbols]

1 ... Rotary transformer, 2, 22 ... Rotor part, 3,
23 ... Stator part, 4, 5, 24, 25 ... Core, 5a ...
Outer peripheral edge, 5b ... Inner peripheral edge, 6, 7, 8, 9, 26, 28 ...
Coil groove, 6a, 7a, 8a, 9a ... coil, 10a,
10b ... chip, 11a, 11b ... crack, 12a, 1
2b, 32a, 32b, 42a, 42b ... Block core, 24a, 25a ... Upper end, 24b, 25b ... Lower end

Claims (5)

[Claims] 1. A rotary transformer comprising a stator core and a rotor core, and a coil housing groove on the facing surface of the core, wherein a block core is provided at an outer peripheral end and / or an inner peripheral end of the stator core and / or the rotor core to prevent cracks and cracks. A rotary transformer characterized by suppressing growth. 2. The rotary transformer according to claim 1, wherein the stator core and the rotor core are disc-shaped. 3. The rotary transformer according to claim 1, wherein the stator core and the rotor core have a cylindrical shape. 4. The rotary transformer according to claim 1, wherein the block core is divided in a circumferential direction. 5. The rotary transformer according to claim 1, wherein the block core is divided in a diameter direction.