JPS5946012A - Rotary transformer - Google Patents

Abstract

PURPOSE:To equalize the coupling coefficients of all channels by increasing at least one sectional area of innermost diameter and outermost diameter channels by specific times as large as other winding wire rods in the rotary transformer in not less than three channel numbers with a winding in which the ratio of rotor-side winding number to stator-side winding number at every channel is 1:3 or more. CONSTITUTION:Rotor cores 1 are set up to a supporter 3, which is fixed to a shaft 4 and turned together with the shaft, concentrical grooves are each formed to stator cores 2 opposed to the rotor cores at a clearance G, and rotor coils 5a-5d and stator coils 6a-6d are each inserted to the grooves. In the constitution, the sectional areas of the coils 5a and 5d are increased by 1.2-2.4 times when the winding ratio of a rotor to a stator is brought to 1:4 and the sectional areas of the coils 5b and 5c are brought to 1, and the coupling coefficients of the channels are equalized approximately.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application] The present invention relates to a rotary transformer for signal transmission suitable for use within a rotary magnetic head mechanism of a magnetic recording/reproducing device.

[Prior art]

Conventionally, in a rotary transformer VC 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 molded, pressed and used as a coil with a rectangular cross section.

In such a rotating transformer vcB, the coupling coefficient between the rotor side winding and the stator side winding is ! l:
It is known that h< and the following equation holds true.

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 3 or more, the leakage inductance between the outermost and innermost windings is lower than that between the windings between them. L is thick. Therefore, the coupling coefficient between the outermost and innermost windings is smaller than the coupling coefficient between the windings existing between them, making the Ik characteristics uniform between channels. The drawback was that there was nothing that could be done.

〔the purpose〕

The object of the invention is to eliminate the above-mentioned drawbacks of the prior art and to make the coupling coefficients of all channels of a rotation unit so uniform.

〔overview〕

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, the rotor core and the stator core are The cross-sectional area of at least one of the innermost and outermost diameter winding wires wound on either side is the innermost diameter j, and 1.2 to 1.2 of the cross-sectional area of the winding gravel other than the outermost channel. 0゜Examples The present invention will be described below with reference to Examples. FIG. 1 shows a four-channel rotary transformer according to an embodiment of the present invention. In FIG. 1, a rotor support 3 has a rotating shaft 4 fixed to the inner diameter of the rotor core and rotates with the rotating shaft 4 by one body weight VC. It is fixed with adhesive. -t, rotor coils 5a and 5b are placed in concentric grooves formed on the side of the rotor core 1 facing the stator core 2.

5c and 5d are arranged and bonded. On the other hand, stator coils ba, 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. In this embodiment, the rotor core 1 and the stator core 2 are opposed to each other with a suitable gap G, the ratio of the number of rotor windings to the number of stator windings is 1:4, and the 20th coil 5b and the 30th coil 5C are When the cross-sectional area of the coil is 1, and the cross-sectional area of the 'J410-tacoil 5a and the 40-tacoil 5d is 1.5, the coupling coefficient of each channel is measured, and the takes shown in Table 1 are obtained.

Table 1 (Actual measurement values of channel 84)
Almost uniform coupling coefficients were obtained for all four channels.

As a result of the experiment, the cross-sectional area of the 10th coil 5a and the 40th coil 5d was 2. 30th-Takoil 5b, 5
It has been found that by setting the ratio of c to the cross-sectional area in the range of 1.2 to 2.4, the coupling coefficients of all channels can be made uniform to a substantially satisfactory value.

In this embodiment, a 4-channel A.Romerite)/S was used as an example, but it is obvious that similar effects can be obtained in a rotary transformer with 3 or more channels. Since it is multiplied by 2 to 24 times, the combined af of all channels can be approximately uniformly 1°.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of one embodiment of a rotary transformer according to the present invention. 1... Rotor core, 2... Skater core, 5 a
, 5b. 5c, 5d...-o-tacoil, 6 a y 6 b
+6c. 6d... Stator coil representative Patent attorney Michi Hiraki A-17 81

Claims (1)

[Claims] (1) A rotor core and a stator core that face each other in a plane, and the rotor core and stator core are arranged in concentric circles facing each other, 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 1:1. In a rotary transformer with three or more channels and three or more 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 defined as the innermost diameter and the outermost diameter channel. 1. A rotary transformer characterized in that the cross-sectional area of each winding material other than the outermost diameter is 1.2 to 2.4 times.