JPH0126083Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to a rotary transformer, and particularly to a rotary transformer suitable for application to a VTR.

(Background Art) Fig. 1 shows a conventional rotary transformer. This rotary transformer is constructed by disposing a rotor and a stator facing each other, and since the rotor and stator have substantially the same structure, only one of them is shown in the drawings. FIG. 1a is a plan view of the rotor (or stator), and FIG. 1b is a sectional view taken along line A-A' in FIG. 1a. In this rotary transformer, a rotor (stator) is constructed by winding a coil 3 in an annular groove 2 formed for each channel on one side of a disk-shaped ferromagnetic core 1. The rotor and stator are arranged such that the surfaces on which the coil 3 is wound face each other. The coil 3 is normally drawn out through a through hole 4 formed at the bottom of the annular groove 3 as shown in the figure.
This is done by drawing it out to the back surface of the core 1 through. Here, the function can be achieved if the number of through holes 4 is equal to the number of channel annular grooves. Although the position of the through hole 4 depends on the design of the rotary transformer, it is usually provided as shown in FIG. 1a in many cases. However, in this case, since the through holes 4 are concentrated in one direction of the core surface, a mass difference occurs between the side where the through holes are not formed, and as a result, problems such as unevenness and characteristic problems due to unbalanced rotation occur. is shown in close-up. In particular, the rotary transformer has 4 channels and 5 channels.
When making multiple channels, the outer diameter of the core becomes larger, which worsens the rotational balance, and the unbalanced pressure during core molding causes distortion in the areas with and without through holes after firing. The disadvantage was that this caused deformation.

(Problems of the invention) The present invention has been made in view of the above, and includes providing a dummy hole as well as a through hole for drawing out the coil at the bottom of the annular groove formed in the core of the rotor and stator that constitute the rotating transformer. To provide a rotary transformer in which rotational balance is achieved and generation of distortion, that is, deformation, can be prevented by arranging the dummy hole and the through hole for drawing out the coil at substantially symmetrical positions with respect to the center of the annular groove. With the goal.

(Structure and operation of the device) The present invention will be explained below based on the drawings.

FIG. 2 is a plan view showing an embodiment of the present invention. In FIG. 2, the same elements as in FIG. 1 are given the same reference numerals. The rotary transformer of this embodiment is constructed with a rotor and a stator arranged opposite each other, as in the conventional example described above, and since the rotor and stator have substantially the same structure, only one of them is shown in the drawings. In the rotary transformer of this embodiment, the rotor (or stator) has a disk-shaped ferromagnetic core 1
An annular groove 2 formed for each channel on one side of the
It is constructed by winding a coil around each. As in the conventional example shown in FIG. 1, the coil is drawn out to the back surface of the core 1 through a through hole 4 formed in an annular groove. This through hole 4 is formed on one side of the surface of the core 1 (the upper half side in FIG. 2).
At the bottom of the annular groove 4 on the other side of the core 1 (lower half side in FIG. 2), dummy grooves 5 are provided in the same number as the through holes 4 and symmetrically. The rotor and stator are arranged so that the surfaces on which the coils are wound face each other with a predetermined distance therebetween.

The rotary transformer of this embodiment configured as described above operates in the same manner as a conventional rotary transformer, but by providing the dummy hole 5 symmetrically with the through hole 4, the rotational balance is improved. It is possible to prevent distortion, that is, deformation, due to unbalanced pressure during core molding.

Furthermore, according to the present invention, as shown in FIG.
In addition to the arrangement of the dummy holes 5 shown in FIG. 2, additional dummy holes 5' can be provided symmetrically in a direction perpendicular to the direction formed by the dummy holes 5 and the through holes 4. This is particularly advantageous when the outer shape of the core 1 becomes large. In other words, if the outer shape of the core 1 is relatively small, there is no problem with the arrangement of the holes as shown in Figure 2, but if the outer diameter is large, the V-shape in the cross-sectional direction of the core 1 is used as shown in Figure 4. Since the deformation in the V-shape becomes large, by arranging the holes as shown in FIG. 3, the deformation is offset, the V-shape deformation can be reduced, and the rotational balance is also improved.

In addition, if the dummy hole is formed so that it can be used as a coil extraction hole, the overall coil extraction hole is made in two or four directions, which reduces the directionality of the coil extraction work and makes the work easier. It has the advantage that it can be rationalized.

(Effects of the invention) As explained in detail above, according to the invention,
A dummy hole is provided at the bottom of the annular groove formed in the rotor and stator cores for rotational balance and distortion prevention as well as a coil extraction hole, so rotational balance is good and distortion or deformation is effectively prevented. becomes possible. Furthermore, by forming the dummy hole so that it can be used as a hole for drawing out the coil, there is an advantage that the directionality of drawing out during the coil drawing operation can be reduced, and the operation can be streamlined.

[Brief explanation of the drawing]

Figure 1a is a plan view of a conventional rotary transformer.
Figure b is a sectional view taken along the line A-A' in Figure 1a, Figure 2 is a plan view of a rotary transformer according to an embodiment of the present invention, Figure 3 is a plan view of a rotary transformer according to a modified example of the present invention, 4
The figure shows B- when the core outer diameter is large in Figure 2.
It is a sectional view taken along the line B'. 1... Core, 2... Annular groove, 3... Coil, 4
...Through hole, 5,5'...Dummy hole.

Claims (1)

[Claims for Utility Model Registration] A rotating transformer having multiple channels, in which one side of a disk-shaped ferromagnetic core is fixed to a rotating part, with a coil provided in an annular groove formed for each channel. The stator includes a rotor, and a stator in which one side of a disk-shaped ferromagnetic core having a coil provided in an annular groove formed for each channel is fixed to a fixed part, and the stator includes the rotor and the core of the stator. A rotating transformer in which the surfaces of the annular grooves face each other at a predetermined interval, and a dummy hole for rotational balance and distortion prevention is provided at the bottom of the annular groove as well as a through hole for coil extraction, and a through hole for coil extraction and a dummy hole for preventing distortion. A rotary transformer characterized in that the dummy holes are arranged at substantially symmetrical positions with respect to the center of the annular groove.