JPS63178510A - Rotary transformer - Google Patents

Abstract

PURPOSE:To remarkably reduce leakage magnetic flux by concentrically boring an orthogonally crossing coil housing groove and housing a wound coil therein for winding a coil of signal transmission system to the surface where the cylindrical core in the relatively rotating concentrical internal cylinder side is opposed to the cylindrical core in the side of external cylinder. CONSTITUTION:An internal cylinder side cylindrical core 8 providing a signal transmission coil 9 at the external surface and an external cylinder side cylindrical core 6 providing a signal transmission coil 7 at the internal surface are concentrically engaged with a small gap and a rotary transformer is obtained by relatively rotating them. In such a constitution, the coils 7 and 9 are generally provided opposed to each other and are provided extending in the axial direction at the surface of core, but the coil housing grooves are bored, unlike such constitution, orthogonally to axis and opposed to each other, to the cores 6 and 6 and the wound coils 9 and 7 are respectively housed therein. Another groove is also provided to a short ring 10 and located at the internal side thereof. Thereby, core height can be reduced and leakage magnetic flux can remarkably be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a rotary transformer used for signal transmission between objects that rotate relative to each other.

2. Description of the Related Art Conventionally, rotary transformers used in video tape recorders have shown a remarkable trend toward higher quality and lower prices. FIG. 3 is a cross-sectional view showing the configuration of the main parts of a conventional rotary transformer. Reference numeral 1 denotes an outer cylindrical core, and a coil 2 is wound around the inner circumference of the core so that the number of turns increases in the axial direction. There is. 3 [Inner cylinder side cylindrical core,
A coil 4 is wound around its outer periphery so that the number of turns increases in the axial direction, and a sig, )'J song is wound between these coils 4.

Problems to be Solved by the Invention However, in the conventional configuration described above, the leakage magnetic flux (■)2 is large as shown in FIG. 4, and the facing cross-sectional area S2, which is a large factor in the characteristic value of inductance, is also large. There was a problem with the characteristics that it was not possible.

The present invention solves the above-mentioned conventional problems, and aims to provide a rotary transformer that can minimize leakage magnetic flux and have a large opposing cross-sectional area within a limited volume. It is something to do.

Means for Solving the Problems In order to achieve this object, the rotary transformer of the present invention has a structure in which the number of turns of the coils wound on the outer cylinder side and the inner cylinder side increases in the direction perpendicular to the axial direction. have.

Function: With this configuration, leakage magnetic flux can be extremely reduced compared to conventional rotary transformers, and the facing area can also be made sufficiently large, making it possible to greatly improve the characteristics.

Embodiment FIG. 1 is a sectional view showing the structure of a rotor IJ-transformer in an embodiment of the present invention. In FIG. 1, 6 is an outer cylindrical core, 7 is an outer cylindrical coil, 8 is an inner cylindrical core, 9 is an inner cylindrical coil, and 10 is a short ring.

In this embodiment, an outer cylindrical core 6 and an inner cylindrical core 8 are used.
Three signal transmission coils are wound in each of the two coils so that the number of turns increases in the direction perpendicular to the axial direction.The width of the groove in which these coils are wound is larger than the diameter of one coil. The dimensions are smaller than the coil diameter. Further, a short ring 10 is wound around the inner cylinder side cylindrical core 8 in the same manner as in a conventional rotary transformer.

In this embodiment, three signal transmission coils are provided, but any number of signal transmission coils may be provided.

Effects of the Invention The present invention has the structure shown in FIG. 2 by configuring the coils wound around the inner and outer cylindrical cores arranged coaxially so that the number of turns increases in the direction perpendicular to the axial direction. As shown in the figure, compared to conventional rotary transformers, leakage magnetic flux, which is a problem in terms of characteristics, can be extremely reduced, and since the facing area can be much larger than conventional rotary transformers within the same volume, the inductance can be increased. It is possible to significantly improve performance.

Furthermore, according to the present invention, the following effects are also achieved.

That is, although the conventional rotary transformer has a dimensionally large space in the direction perpendicular to the axis, it has the disadvantage that it becomes large in the height direction. However, according to the present invention, there is an effect that the height can be made sufficiently small even when there is a limit in the height direction.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the main parts of a rotary transformer according to an embodiment of the present invention, FIG. 2 is an explanatory diagram for explaining the same characteristics, and FIG. FIG. 4 is an explanatory diagram showing problems in the characteristics of a conventional rotary transformer. 6...Outer cylinder side cylindrical core, 7...Outer cylinder side coil, 8...Inner cylinder side cylindrical core, 9...
・Inner cylinder side coil, 1Q...Short ring. Name of agent: Patent attorney Toshio Nakao and one other person
--Ta F section 11 Cylindrical core γ --- Dato Makoto II coil 8- Inner cylinder side) ■Core q-11 Inner space 4th coil, Figure lθ-11 Side link Otsu γ β Figure 2

Claims (1)

[Claims] At least one signal transmission system includes a coil wound around an inner cylindrical core and an outer cylindrical core that are coaxially arranged.
A rotary transformer whose wires are wound so that the number of turns increases in the direction perpendicular to the axial direction.