JPH05128983A - Device for feeding power to rotary body - Google Patents

Abstract

PURPOSE:To feed power to a rotary body without generating a friction. CONSTITUTION:While a waveguide 6 for transmission is provided in an envelope 1 for housing a rotary body 9, a waveguide 5 for receiving is provided to the above rotary body 9 so as to oppose to the waveguide 6 for transmission. And by the spatial combination of the waveguide 6 for transmission with the waveguide 5 for receiving, the power is fed from the fixed side to the rotary body 9 side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device for a rotating body which is suitable for supplying power to a rotary cathode provided in a rotary cathode type X-ray tube device.

[0002]

2. Description of the Related Art A rotating cathode type X-ray tube device recently proposed for ultra-high speed X-ray CT is an X-ray tube formed in a donut shape so as to surround the periphery of a subject, and is an annular vacuum chamber. A rotating body provided with a cathode filament is arranged in an envelope for rotation, and a ring-shaped fixed anode is fixed to the annular vacuum envelope so as to face the rotating body. The cathode filament rotates with the rotation of the rotating body, and the collision position of the electron flow colliding with the ring-shaped fixed anode moves in the circumferential direction of the ring-shaped fixed anode, whereby the emission position of the X-ray emitted toward the subject. Moves at high speed around the subject.

Conventionally, in such a rotary cathode type X-ray tube device, power is supplied to the rotating body by sliding a power supply brush to a slip ring attached to the rotating body.

[0004]

However, in the above-described conventional power feeding device for a rotating body, dust is generated due to wear of the power feeding brush and is dispersed in the vacuum envelope, so that the dust of the vacuum envelope is not generated. There are problems that the degree of vacuum is lowered and the withstand voltage performance is deteriorated. In addition, the conventional power supply device has a problem that its life is relatively short due to wear of the power supply part.

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a power feeding device for a rotating body, which is improved so as not to cause wear at a power feeding portion.

[0006]

In order to achieve the above object, in the power feeding device for the rotating body according to the present invention, the transmitting waveguide is provided in the envelope in which the rotating body is housed. The rotating body is characterized in that a receiving waveguide is provided so as to face the transmitting waveguide, and by the spatial electromagnetic coupling between the transmitting waveguide and the receiving waveguide, Electric power can be supplied from the fixed side to the rotating body side even during non-contact rotation.

Further, in the power feeding device for another rotating body according to the present invention, a plurality of concentric donut-shaped electrodes are attached to the rotating body and the inside of the envelope in which the rotating body is housed, and their centers are attached. Correspond to the central axis of rotation, and the donut-shaped electrodes on the rotating body side and the donut-shaped electrodes on the envelope side face each other. I'm trying to occur. By such non-contact electrostatic coupling, electric power can be supplied from the fixed side to the rotating side without contact during rotation.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a rotating cathode type X-ray tube device for ultra-high speed X-ray CT, to which a power feeding device for a rotating body according to a first embodiment of the present invention is applied. In FIG. 1, the envelope 1 is made of, for example, stainless steel in an annular shape and is evacuated. A subject (not shown) is inserted into the center hole 11.

In the envelope 1, a ring-shaped rotating body 4 is provided.
, And is magnetically levitated by an electromagnet (not shown), and is rotationally driven at, for example, 10 Hz by an induction motor (not shown). One cathode filament 2 made of, for example, tungsten is fixed to one point of this rotating body 4. This filament 2 rotates with the rotation of the rotating body 4 and draws a circular orbit. A ring-shaped anode 3 is fixed inside the envelope 1 so as to face the circular orbit. When electrons are generated from the filament 2 and collide with the facing anode 3, X-rays are generated and emitted in the direction of the central hole 11, and the subject in the central hole 11 is irradiated with X-rays. When the rotator 4 rotates, the filament 2 also rotates and the electron collision position rotates, so that the X-ray focal point circulates around the subject.

A transmission waveguide 6 is provided inside the envelope 1, and an ultra high frequency power is sent from an ultra high frequency power supply 7. On the other hand, a receiving waveguide 5 is attached to the rotating body 4. The transmitting and receiving waveguides 6 and 5 are formed in a ring shape in axial symmetry with respect to the rotation center axis of the rotating body 4, so that the electromagnetically coupled state is maintained even during rotation. ..

As a result, the electromagnetic wave (microwave, millimeter wave) sent from the transmitting waveguide 6 is efficiently received by the receiving waveguide 5 even while the rotating body 4 is rotating. In this way, the filament 2 is heated by the electric power supplied to the rotating body 4 side in a non-contact manner. On the other hand, a high voltage generator (not shown) is connected between the transmission waveguide 6 and the anode 3 to form a high potential difference between the filament 2 and the anode 3. Then, the thermoelectrons emitted from the filament 2 collide with the anode 3 to generate X-rays.

FIG. 2 shows a second embodiment of the present invention. In this figure, power is supplied to the rotating body 4 by electrostatic coupling of the donut-shaped metal plates 81 and 83 and the donut-shaped metal plate 8.
It is made by capacitive coupling of 2,84. That is, two concentric donut-shaped metal plates 83 are provided inside the envelope 1.
84 is fixed. Two concentric donut-shaped metal plates 81, 82 are also attached to the rotating body 4. These donut-shaped metal plates 81 to 84 are attached such that their centers coincide with the rotation center axis of the rotating body 4. And the donut-shaped metal plates 83, 8 on the side of the envelope 1
An AC power supply 9 is connected to 4. The other structure is similar to that of FIG.

Since the donut-shaped metal plates 81 to 84 are attached as described above, their facing positional relationship is maintained even during rotation of the rotating body 4, and the electrostatically coupled state is maintained. Therefore, due to this electrostatic coupling, electric power can be supplied to the rotating body 4 side without contact even during rotation of the rotating body 4, and power can be supplied to the filament 2.

FIG. 3 shows a modification of the second embodiment. In FIG. 3, the AC power sent through the electrostatic coupling by the donut-shaped metal plates 81 to 84 is used to convert the AC power.
To lower the voltage. The transformer 10 is attached to the rotating body 4. By inserting such a transformer 10, the voltage can be lowered and the current can be increased, so that the current supplied from the AC power supply 9 can be reduced while the current flowing through the filament 2 can be increased. Therefore, the voltage drop in the doughnut-shaped metal plates 81 to 84 is reduced, which has the effect of increasing the power supply efficiency.

[0015]

As described in the above embodiments, according to the power feeding device for a rotating body of the present invention, electromagnetic or electrostatic coupling is used to contact the rotating body from the fixed side in a non-contact manner. It becomes possible to supply power, and there is no wear or dust at the power supply part unlike the case where power is supplied using the conventional slide mechanism consisting of a slip ring and a brush,
The reliability can be improved and the life can be extended.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a first embodiment of a power feeding device for a rotating body according to the present invention.

FIG. 2 is a schematic cross-sectional view showing the second embodiment.

FIG. 3 is a conceptual diagram showing a modified example.

[Explanation of symbols]

 1 Enclosure 11 Center Hole 2 Filament 3 Anode 4 Rotating Body 5 Receiving Waveguide 6 Transmitting Waveguide 7 Super High Frequency Power Supply 81-84 Donut Metal Plate 9 AC Power Supply 10 Transformer

Claims (2)

[Claims] 1. An envelope, a rotating body that rotates in the envelope, a transmission waveguide fixed inside the envelope, and the rotation so as to face the transmission waveguide. A power supply device for a rotating body, comprising: a receiving waveguide attached to the body. 2. An envelope, a rotating body that rotates in the envelope, and a plurality of concentric circles, the center of which is fixed to the rotation center axis of the rotating body, which is fixed inside the envelope. To a rotating body comprising: a donut-shaped electrode; and a plurality of donut-shaped electrodes, the centers of which are attached to the rotating body so as to face each of the plurality of donut-shaped electrodes and whose center coincides with the rotation center axis Power supply device.