JPH0218842A - Rotating anode x-ray tube - Google Patents

Abstract

PURPOSE:To continuously radiate X-rays without lowering the life of bearings by arranging at least two anode targets in a vacuum container. CONSTITUTION:Electrons are emitted from either one of cathodes, e.g., a cathode 11a, during the ordinary use, electrons collide with an anode target 12a rotated at a high speed by the rotation of a rotor 13a to generate X-rays. When a ball bearing 14a is made a high temperature after a fixed time, the emission of electrons from the cathode 11a is stopped, the rotation of the anode target 12a is stopped to cool the ball bearing 14a. As soon as the emission of electrons from the cathode 11a is stopped, electrons are emitted from a cathode 11b, electrons collide with an anode target 12b rotated at a high speed by the rotation of a rotor 13b to generate X-rays. When a ball bearing 14b is made a high temperature after a fixed time, the emission of electrons from the cathode 11b is stopped, the rotation of the anode target 12b is stopped to cool the ball bearing 14b. Ball bearings are prevented from becoming a high temperature.

Description

[Detailed description of the invention] [[Objective] of the invention (Field of use of I' work J-) The present invention relates to rotating anode x-ray tubes.

(Prior Art) FIG. 5 is a schematic cross-sectional view showing a conventional rotating anode X-ray tube. As shown in this figure, a cathode 2 that emits electrons and an anode target 4 fixed to a rotor 3 are placed facing each other in a vacuum container 1 that is airtight to a high vacuum. is a ball bearing 5a.

It is rotatably supported by a fixed shaft 6 via 5b. The rotor 3 is rotated by a rotating magnetic field generated by a rotating magnetic field generator (not shown) disposed around the outer periphery of the vacuum container 1, and the rotation of the rotor 3 causes the target 4 to rotate integrally.

In the F rotary anode XFA tube, when electrons emitted from the cathode 2 collide with the anode target 4, X-rays are generated, and at this time, the anode target 4 reaches a high temperature exceeding 1000°C.

In this way, when the anode target 4 becomes high temperature, the ball bearings 5a and 5b become
The temperature reaches 0°C or higher.

(Problem to be Solved by the Invention) As described above, when X-rays are generated, the anode target 4 becomes high temperature, so the ball bearings 5a and 5b also become high temperature, and the ball bearing 5
The lubricating function of the lubricant a*5b decreases as the temperature increases, so the service life of the ball bearings 5a and 5b becomes known. For this reason, in the past, it was necessary to stop the generation of XS* for a certain period of time in order to cool down the anode target 4, which had reached a high temperature, and there was a disadvantage that it was impossible to continuously generate/generate XFI.

The present invention has been made for the purpose of solving the problems mentioned in "2" above, and it is possible to improve Xg without reducing the service life of the bearing. The purpose of this invention is to provide a rotating anode X-ray tube that can continuously irradiate.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention has a cathode that emits electrons in a vacuum container, and X-rays are generated by collision of the electrons emitted from the cathode. An anode target that generates a The configuration was such that at least two anode targets were provided.

Furthermore, rotating magnetic field generators may be provided on the outer periphery of the vacuum vessel in correspondence with the rotors fixed to each of the anode targets, and a heat sink or a heat sink may be provided between each of the anode targets. A shielding plate may be provided.

(Function) According to the present invention, by arranging at least two anode targets in a vacuum container, X-rays can be continuously irradiated by operating each anode target at regular intervals. .

(Example) Hereinafter, the present invention will be explained in detail based on the illustrated example.

Fig. 1 is a cross-sectional view showing a rotating anode X-ray tube according to the present invention. As shown in this figure, cathodes 11a, 1111 and , anode targets 12a and 12b are respectively arranged to face each other.Rotors 13a and 13b are fixed to the anode targets 12a and 12tl, respectively, and each rotor 13a and 13b is provided with a ball bearing 14a and a ball bearing 14a, respectively. The rotors 13a, 13b, ball bearings 14a, 14b, and fixed shafts 15a, 15b are also arranged within the vacuum vessel 10.

A rotating magnetic field generator (not shown) is provided on the outer periphery of the vacuum vessel 10 facing the rotors 13a and 13b, respectively.
First, as the rotors 13a and 13b are rotated by the rotating magnetic field generated by each rotating magnetic field generator, the anode targets 12a and 12b are also rotated together.

In this way, in the vacuum container 10, there are two sets of rotors 13a, 113b, 111, which can rotate and stop independently.
Unipolar targets 12a and 12b are arranged.

The rotating anode X-ray tube according to the present invention is configured as described above, and during normal use, electrons are emitted from one side, for example, the cathode 11a, and the anode target is rotated at high speed by the rotation of the rotor 13a. Add electrons to 12a! i to generate X-rays. After a certain period of time, the radiation from the high temperature anode targeter T-128, the rotor 13a, and the fixed shaft 15a are removed.
When the ball bearing 14a becomes high temperature due to heat conduction from the ball bearing 14a, the emission of electrons from the cathode 118 is stopped to stop the rotation of the small pole get 12a, thereby cooling the ball bearing 14a.

At the same time that the emission of electrons from the cathode 11a is stopped, Imamaro emits electrons from the cathode 11b, and collides the electrons with the anode 12b, which is rotating at high speed due to the rotation of the rotor 13b, to generate X-rays. let After a certain period of time, the radiation from the anode target 12b, which has reached i3 temperature, and the rotor 13
When the ball bearing 14b becomes hot due to heat conduction from the b1 fixed @ 15b, the emission of electrons from the cathode 11b is stopped, the rotation of the anode target 120 is stopped, and the ball bearing 14b is cooled down. Note that the rotation of the rotor 13b is stopped when electrons are emitted from the cathode 13a, and the rotation of the rotor 13a is stopped when electrons are emitted from the cathode 13b.

In this way, from the cathodes 11a and 11b to the anode target 1
By emitting electrons to the bearings 2a and 12b at regular intervals, it is possible to prevent the ball bearings 14a and 141) from becoming too hot, allowing continuous operation.
It is possible to continuously irradiate stable X-rays with Q=1.

Note that it is not necessary to provide two cathodes corresponding to the anode targeters t-12a and 12b, and one cathode may be used by changing its direction.

In the embodiment shown in FIG. 1, the two sets of anode targets 12a and 12b are provided with independent rotors 138 and 13, respectively.
11, ball bearings 14a, 14b, fixed shafts 15a, '15b
Since the ball bearings 14a and 14b are rotatably supported by the ball bearings 14a and 14b, the temperature of the high temperature ball bearings 14a and 14b can be significantly reduced.

In the embodiment described in FIG. 1, two navy blue cathode and anode targets are crossed n1. :Although there was a configuration in which X-rays were generated, it is also possible to generate X-rays simultaneously from two sets of cathode and anode targets.

Further, it is also possible to arrange two or more sets of cathodes and anode targets in a vacuum container and to sequentially operate them at regular intervals.

FIG. 2 is a sectional view showing a rotating anode X-ray tube according to claim 2 of the present invention.

In this example (1), inside the vacuum container 30, which is airtight to a high vacuum, there is a fixed shaft 31 fixed to the vacuum container 30 via a connecting part 31a, and a fixed shaft 31 connected to the fixed shaft 31 via ball bearings 32a, 32b. rotors 33a and 33b rotatably supported;
Anode targets 34a, 34b, etc. installed at both ends of the rotors 33a, 331+, anode targeters t-34a, 34b
Shades 81i, 35a and 35b are provided facing each other. On the outer periphery of the vacuum container 30 facing the rotors 33a and 33b, there are rotating magnetic field generators 36a and 36b, respectively.
36b is arranged, and this rotating magnetic field generator 36a,
36b-c generated rotation! rotor 33a by a field
.

33b rotate independently.

In this manner, in this example, the rotors 33a and 33b are rotated and stopped independently by the rotating magnetic field generators 36a and 361), so the anode targets 34a and 34t+ are rotated and stopped independently.

Therefore, as in the above embodiment, electrons are transferred from the negative electrodes 135a and 35b to the anode target plates 1-34a and 34b at a constant ff,
By radiating alternately every j interval, the ball bearing 32a
, 32b can be prevented from becoming nW, continuous operation is possible, and stable X-rays can be continuously irradiated.

In addition, since the rotors 33a and 33b are rotatably arranged so as to be divided into two by the 31P frame portion 31a of the fixed shaft 31, the quality of each rotor 33a and 33b is shortened to half the culm of the conventional one. can do. Therefore, each rotor 33a
, 33b can be increased, alignment adjustment of the fixed 1-bit 31, etc. can be performed more accurately, and stable xrr+ with small vibration amplitude can be irradiated. .

FIG. 3 is a sectional view of a rotating anode X-ray tube according to claim 3 of the present invention.

In this example, instead of the connecting part 31a of the fixed shaft 31 with the vacuum vessel 30 shown in FIG. The fixing member 111131 is fixed to the vacuum container 30 by a heat dissipation plate 37. II!
1 is similar to the embodiment shown in FIG. 2 above.

In this example, when X-rays are irradiated from the anode targets 34a and 3/Ib to the alternating current (0=1) at regular intervals, heat is transferred from the fixed shaft 31 and the ball bearings 328, 32b, which become hot, to The heat transferred to f' becomes empty'? 'f device 3
Heat is transferred to the tip side that protrudes from zero.

And a storage container χ) (not shown) that stores 8 vacuum devices 30.
Heat is transferred to the medium (for example, oil) placed inside by convection, resulting in cooling fJ].

In this way, in this example, the fixed shaft 31 and the ball bearings 32a, 32b can be cooled by the heat sink 37. Therefore,
From negative 1435a, 35b to anode target 3/Ia,
When electrons are exchanged with the ball bearings 34b at regular intervals, it is possible to prevent the ball bearings 32a and 32b from becoming high temperature, so as shown in FIGS. It is possible to irradiate XFA continuously and stably in a better manner than in the example.

Note that the distal end side of the heat dissipation plate 37 may be extended and fixed to the storage container (not shown) of the vacuum container 30. In this case, the fixed shaft 31 can be fixed more firmly.
1 vibration is suppressed, and more stable X-rays can be irradiated.

FIG. 4 is a sectional view of a rotating anode X-ray tube according to a fourth aspect of the present invention.

In this example, the cathode 11a of the rotating anode X-ray tube shown in FIG.
11b and the anode target 128.12b, a disc-shaped heat shielding plate 1G made of a copper plate or the like is provided with its tip end protruding from the vacuum vessel 10. The other configurations are the same as the embodiment shown in FIG. 1 above.

In this example, the heat radiated from the anode targets 12a and 12b when XFil is alternately irradiated at regular intervals is as follows:
The heat is absorbed by the heat shield plate 16 and no heat is transferred to the opposite side.

The heat absorbed by the heat shield plate 16 is transferred to the tip side protruding from the vacuum container 10. Then, a medium (for example, oil) is placed in a storage container (not shown) containing the vacuum container 10.
Heat transfer occurs through convection and cooling occurs.

In this way, in this example, electrons are transferred from the cathodes 11a and 11b to the anode targets 12a and 12b alternately at regular intervals h4.
When the heat is irradiated once, the heat is not transferred to the opposite side of the heat shielding plate 16. Therefore, it is possible to prevent the ball bearings 14a and 14b from becoming high temperature, so that X-rays can be irradiated more continuously and stably than in the embodiments shown in FIGS. 1 and 2. I can do it.

[Effects of the Invention] As explained above, according to the present invention, it is possible to prevent the bearing from becoming high temperature, so the continuous and stable X
It is possible to irradiate a beam and perform efficient and labor-intensive operation.

Furthermore, in the rotating anode X-ray tube of claim 2, the rotational frequency of the fixed shaft is increased by arranging rotating magnetic field generators corresponding to the rotors to increase the rotating magnetic field. 1, using stable X-rays with small vibration amplitude.
can do.

Furthermore, in the rotating anode X-ray tube according to claim 3.4, the temperature of the bearing can be significantly reduced by the heat sink and the heat shield plate, and stable X-rays can be continuously irradiated.

[Brief explanation of the drawing]

Figure '1 is a sectional view showing a rotating anode X-ray tube according to the present invention;
FIGS. 2, 3, and 4 are sectional views showing rotating anode XFA tubes according to other embodiments of the present invention, and FIG. 5 is a sectional view of a conventional rotating anode J4i X-ray tube, but not shown. 10.20.30... Vacuum container 11a, 1 lb, 35a, 35b... Cathode 12a,
12b, 34a, 34b... Anode target 13a, 13b, 33a, 33b... Rotor 14a, 14b, 32a, 32b... Ball bearing 15a
, 15b, 31... Fixed shaft 16... Heat shield plate 35a, 3611... Rotating magnetic field generator 37... Heat sink

Claims (1)

[Claims] (1) A cathode that emits electrons, an anode target that generates X-rays by collision of the electrons emitted from the cathode, and an anode target that is integrally fixed in a vacuum container. A rotating anode X-ray tube comprising a rotor and a bearing rotatably supporting the anode target, characterized in that at least two anode targets are disposed within the vacuum vessel. (2) A rotating magnetic field generator is disposed on the outer periphery of the vacuum container in correspondence with a rotor fixed to each of the anode targets.
The rotating anode X-ray tube described. (3) The rotating anode X-ray tube according to claim 1 or 2, characterized in that a heat sink is provided between each of the anode targets. (4) The rotating anode X-ray tube according to claim 1, wherein a heat shield plate is provided between each of the anode targets.