JPH0636939A - Rotary transformer - Google Patents

Abstract

PURPOSE:To realize miniaturization without decreasing transmission efficiency of electric signal, by winding a first coil so as to overlap only in the direction parallel with a rotary shaft, and winding a second coil so as to overlap only in the direction parallel with the rotary shaft. CONSTITUTION:In a rotary transformer 22, winding trenches 23a, 24a are formed in a rotor core 23 and a stator core 24 made of ferrite, respectively. A coil 16 of, e.g. two turns is wound in the direction parallel with a rotary shaft 6, in the winding trench 23a of the rotor core 23 side. A coil 17 of, e.g. four turns is wound in a winding trench 24a of the stator core 24 side. Thereby a rotary transformer can be made small as compared with the conventional one, without decreasing transmission efficiency of electric signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary transformer, and more particularly to improvement of a plane-opposed rotary transformer.

[0002]

2. Description of the Related Art Conventionally, a rotary head device used in a video tape recorder or the like is constructed as shown in FIG.

In the figure, reference numeral 1 denotes a rotary head device as a whole, a stator 3 is fixed to a substrate 2, and a rotary shaft 6 is rotatably supported by the stator 3 via bearings 4a and 4b.

The rotating shaft 6 forms an output rotating shaft of the motor 10, and an engaging member 7 is fixed to the tip portion thereof. A rotary cylinder 8 is fixed to the engaging member 7. The magnetic head fixed to the rotary cylinder 8 rotates together with the magnetic tape sliding on the peripheral side surface of the rotary cylinder 8. ing.

The stator 3 has a rotary transformer 1
The second stator core 14 is fixed, and the rotor core 13 of the rotary transformer 12 is fixed to the engagement member 7 on the rotor side, so that the rotor core 13 can rotate freely with a minute gap from the stator core 14. There is.

As shown in FIG. 6, the stator core 14 is in the shape of a disk and has concentric winding grooves 14a. The winding grooves 14a are formed by the number of channels of the magnetic head provided in the rotary cylinder 8. The stator core 13 also has a similar winding groove 13a.

Further, as shown in FIG. 7, the winding grooves 13a and 14a of the rotor core 13 and the stator core 14 are formed at positions facing each other.
Windings 16 and 17 are wound around 4a, respectively. Thus, the electric signal input from the outside is transmitted to the magnetic head of the rotary cylinder 8 through the rotary transformer 12 in a non-contact manner.

[0008]

In the rotary transformer 12 of this type, the windings 16 and 1 are arranged in the direction parallel to the facing surfaces of the rotor core 13 and the stator core 14.
It was necessary to increase the width L ₁ of the winding grooves 13a and 14a in order to secure the required number of turns by winding 7 in a stacked manner.

However, in the rotary transformer 12, there is a problem that the transmission efficiency of the electric signal is lowered when the width L ₁ of the winding grooves 13a and 14a is increased.

Further, the rotor core 13 and the stator core 14
If the width L ₂ from the outermost circumference to the winding grooves 13a and 14a and the interval L ₃ between the winding grooves 13a and 14a become smaller, the transmission efficiency of the electric signal decreases. Therefore, in order to obtain a practically sufficient transmission efficiency, the width L ₂ from the outermost circumference of the stator core 14 to the winding grooves 13a and 14a and each winding groove 13
When the distance L ₃ between a and 14a is increased, the diameter of the rotor core 13 and the stator core 14 must be increased accordingly.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a rotary transformer which can be miniaturized without lowering the transmission efficiency of electric signals.

[0012]

According to the present invention, the above object is to form a concentric winding groove in a rotor core that rotates about a rotary shaft, and to wind the first winding in this groove. In addition, by forming a concentric winding groove in the stator core arranged to face the rotor core and winding the winding in the groove, the space between the first winding and the second winding is formed. In a rotary transformer for transmitting an electric signal in a non-contact manner, the first winding is overlapped and wound only in a direction parallel to the rotary shaft, and the second winding is wound around the rotary shaft. This is achieved by a rotary transformer that is wound only in parallel and in parallel.

Further, the above-mentioned object is to provide the first winding and the second winding.
At least one of the windings can be achieved by a rotary transformer in which the number of turns in the direction parallel to the rotation axis is larger than the number of turns in the direction orthogonal to the rotation axis.

Further, preferably, the first winding and the second winding
Both of the windings are configured so that the number of turns in the direction parallel to the rotation axis is larger than the number of turns in the direction orthogonal to the rotation axis.

Therefore, the winding groove of the rotor core and the winding groove of the stator core each have a length in a direction parallel to the rotation axis longer than a length in a direction orthogonal to the rotation axis. Can be configured as

[0016]

With respect to the first and second windings, the number of turns in the direction perpendicular to the rotation axis is made larger than the number of turns in the direction orthogonal to the rotation axis. The width of the winding grooves of the core and the stator core can be reduced.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the examples described below are suitable specific examples of the present invention, and therefore, various technically preferable limitations are given, but the scope of the present invention particularly limits the present invention in the following description. Unless otherwise stated, the present invention is not limited to these modes.

FIG. 1 shows a configuration common to that of the prior art with the same reference numerals as in FIG. 7. In the figure, the rotary transformer 22 is formed of ferrite with a rotor core 23 and a stator core 24 having winding grooves 23a and 24a, respectively. Has been done.

Regarding the shape of the winding groove 23a, the depth H ₁ is width L ₁₁
The winding 16 has a rectangular shape that is larger than the above, and the winding 16 is wound so as to overlap only in a direction parallel to the rotation axis 6. Similarly, the winding groove 24a has a rectangular shape in which the depth H ₂ is larger than the width L ₁₅ ,
The winding wire 17 is wound so as to overlap only in the direction parallel to the rotating shaft 6.

In the rotary transformer 22 of this embodiment, the winding 16 is wound in the winding groove 23a on the rotor core 23 side, for example, twice in the direction parallel to the rotating shaft 6, and further on the stator core 24 side. Winding 17 is wound around 24a four times, for example.

Therefore, the width L of the winding grooves 23a and 24a
₁₁ and L ₁₅ are of such a size that only one winding 16 and 17 can be accommodated. Even when the number of windings 16 and 17 is increased, the dimensions of the depths H ₁ and H ₂ of the winding grooves 23a and 24a are large. You can store this by just increasing the size.

Therefore, the rotary transformer 22 includes the winding 1
Since 6 and 17 are wound in a direction parallel to the rotation axis, windings 16 and 17 are wound in a direction perpendicular to the rotation axis as compared with the conventional case (FIG. 7). Line groove 23a
The widths L ₁₁ and L ₁₅ of 24 and 24a can be narrowed.
Therefore, the diameter D ₁ of the rotary transformer 22 can be reduced without reducing the distance L ₁₃ between the winding grooves 23a and 24a and the distance L ₁₂ from the outermost circumference of the rotor core 23 and the stator core 24 to the winding grooves 23a and 24a. Can be converted.

Therefore, the rotary transformer 22 can be miniaturized without lowering the transmission efficiency of electric signals.

In the above-described embodiment, the diameter of the rotary transformer 22 having the same number of channels as the conventional one has been described, but the present invention is not limited to this, and more rotary transformers having the same diameter are used. The number of channels may be increased by forming the line groove.

For example, as shown in FIG. 2, the rotary transformer 32 has a structure in which the winding grooves 33a and 34a are formed more than in the conventional case (FIG. 7) and the number of channels is increased. In this rotary transformer 32,
By winding the windings 16 and 17 in a direction parallel to the rotating shaft 6, the widths of the winding grooves 33a and 34a are the same as in the case of FIG. 1 and are smaller than those of the conventional winding grooves 13a and 14a. It is narrowly formed.

Therefore, since the width of the winding grooves 33a and 34a is narrowed, the number of the winding grooves 33a and 34a can be increased without increasing the diameter of the rotary transformer 33. Can be increased.

In the above embodiment, the winding 16 is wound twice in the winding groove 23a on the rotor core 23 side, and the winding 17 is wound four times in the winding groove 24a on the stator core 24 side. However, the present invention is not limited to this,
For example, as shown in FIG. 3, the winding groove 43 on the rotor core 23 side
It is possible to apply various numbers of windings, such as winding the winding 16 once on a and winding the winding 17 twice on the winding groove 44a on the stator core 24 side. In this case, the depths of the winding grooves 43a and 44a may be formed according to the number of turns.

In the above-mentioned embodiment, the case where the windings 16 and 17 are wound in a direction parallel to the rotary shaft 6 is described, but the present invention is not limited to this, and the number of turns is increased. In this case, as shown in FIG. 4, they may be stacked in a direction orthogonal to the rotary shaft 6. In this case, by increasing the number of turns in the direction parallel to the rotary shaft 6 more than the number of turns in the direction orthogonal to the rotary shaft 6, the same effect as the above case can be obtained.

Further, in the above-mentioned embodiments, the case where the present invention is applied to the rotary transformer of the video tape recorder has been described, but the present invention is not limited to this, and is widely applied to rotary transformers used in various other devices. can do.

[0030]

As described above, according to the present invention, the rotary transformer can be made smaller than the conventional one without lowering the transmission efficiency of electric signals.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a rotary transformer according to the present invention.

FIG. 2 is a sectional view showing another embodiment.

FIG. 3 is a partial cross-sectional view showing another winding method.

FIG. 4 is a partial cross-sectional view showing another winding method.

FIG. 5 is a cross-sectional view showing the configuration of a rotary head device.

FIG. 6 is a perspective view showing the configuration of a rotary transformer core.

FIG. 7 is a schematic cross-sectional view showing the configuration of a conventional rotary transformer.

[Explanation of symbols]

6 rotary shafts 12, 22, 32 rotary transformers 13, 23, 33 rotor cores 14, 24, 34 stator cores 13a, 23a, 33a, 14a, 24a, 34a
Winding groove 16 and 17 windings.

Claims (4)

[Claims] 1. A concentric winding groove is formed in a rotor core rotating about a rotation axis, a first winding is wound around this groove, and a concentric circle is formed in a stator core arranged to face the rotor core. In a rotary transformer for transmitting an electric signal in a non-contact manner between the first winding and the second winding by forming a winding groove in the shape of a coil and winding the winding in the groove, One winding is superposed and wound only in a direction parallel to the rotation axis, and the second winding is superposed and wound only in a direction parallel to the rotation axis. Yes, a rotary transformer. 2. At least one of the first winding and the second winding has a greater number of turns in a direction parallel to the rotation axis than a number of turns in a direction orthogonal to the rotation axis. The rotary transformer according to claim 1, wherein 3. The first winding and the second winding both have a greater number of turns in a direction parallel to the rotation axis than a number of turns in a direction orthogonal to the rotation axis. The rotary transformer according to claim 1. 4. The winding groove of the rotor core and the winding groove of the stator core each have a length in a direction parallel to the rotation axis longer than a length in a direction orthogonal to the rotation axis. It is configured as described in claim 1.
The rotary transformer described in.