JPS6314844B2 - - Google Patents

Description

[Detailed description of the invention]

[Field of Application] The present invention relates to a rotary transformer for signal transmission suitable for use in a rotary magnetic head mechanism of a magnetic recording/reproducing device. [Prior art] Conventionally, in a rotary transformer with three channels or more, the coil wire of the rotor side winding, where the ratio of the number of windings on the rotor side to the number of windings on the stator side is 1:3 to 1:6, is a circular wire of the same size and diameter. It was formed into a shape, pressed and used as a coil with a rectangular cross section. In such a rotary transformer, it is known that the coupling coefficient between the rotor side winding and the stator side winding is expressed by the following equation, where K is the coupling coefficient. Here, l is the leakage inductance and L is the combined inductance. By the way, in a rotating transformer in which the ratio of the number of windings on the rotor side to the number of windings on the stator side is 1:3 or more, there is more leakage between the outermost and innermost windings than between the windings between them. inductance l
is large. Therefore, the coupling coefficient K between the outermost and innermost windings is smaller than the coupling coefficient K between the windings existing between them, and there is a drawback that the electrical characteristics between channels cannot be made uniform. It was hot. [Objective] An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art and to make the coupling coefficients of all channels of a rotary transformer substantially uniform. [Summary] A feature of the present invention is that in a rotary transformer having three or more channels in which the ratio of the number of windings on the rotor side to the number of windings on the stator side for each channel is 1:3 or more, either the rotor core or the stator core is The cross-sectional area of at least one of the innermost and outermost channels wound on either side is 1.2 of the cross-sectional area of the winding wire other than the innermost and outermost channels.
It is at the point where it has been increased by ~2.4 times. [Example] The present invention will be explained below using Examples. FIG. 1 shows a four-channel rotary transformer according to an embodiment of the present invention. In FIG. 1, a rotor core 1 is adhesively fixed to a rotor support 3 which has a rotating shaft 4 fixed to its inner diameter and rotates integrally with the rotating shaft 4. As shown in FIG. Rotor coils 5a, 5b, 5 are placed in concentric grooves formed on the side of the rotor core 1 facing the stator core 2.
c and 5d are placed and bonded. On the other hand, stator coils 6a, 6b, 6c, and 6d are bonded in grooves of the stator core 2 on the side facing the rotor core 1 of the stator core 2. Rotor core 1
and stator core 2 are opposed to each other with a suitable gap G between them. In this embodiment, if the ratio of the number of rotor windings to the number of stator windings is 1:4 and the coil cross-sectional area of the second rotor coil 5b and the third rotor coil 5c is 1, then the first rotor coil 5a and the When the coupling coefficient of each channel was measured assuming that the cross-sectional area of the four-rotor coil 5d was 1.5, the data shown in Table 1 was obtained.

〔effect〕

As described above, according to the present invention, the cross-sectional area of the rotor-side winding of the innermost channel and the outermost channel is made 1.2 to 2.4 times the cross-sectional area of the rotor-side winding existing between these. , the coupling coefficients of all channels can be made almost uniform.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of a rotary transformer according to the present invention. 1...Rotor core, 2...Stator core, 5
a, 5b, 5c, 5d...rotor coil, 6a,
6b, 6c, 6d...Stator coils.

Claims (1)

[Claims] 1. A rotor core and a stator core that face each other in a planar manner, and are provided substantially concentrically opposite each other to the rotor core and stator core, and the ratio of the number of windings on the rotor side to the number of windings on the stator side for each channel is 1:3.
In a rotary transformer with three or more channels having the above windings, the cross-sectional area of the winding material of at least one of the innermost and outermost channels wound around either the rotor core or the stator core is calculated as follows: A rotary transformer characterized in that the cross-sectional area of the winding materials other than the outer diameter channel is 1.2 to 2.4 times larger.