JPS643024B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an enclosed rotating anode X-ray device in which heat generated by electron impact is dispersed by rotating a disc-shaped anode cathode enclosed in a vacuum container. It concerns improvements to pipes.

(Prior art) Generally, in order to generate powerful X-rays, a rotating anticathode X-ray tube is widely used, which rotates the anticathode to increase the cooling effect against the heat generated by the generation of X-rays in the anticathode section. ing. However, in order to cool a conventional rotating anode, cooling water is supplied from outside the vacuum vessel to the hollow part of the rotating anode through a hollow rotating shaft connected to the rotating anode, and warm water after cooling is also supplied to the hollow part of the rotating anode. A cooling method was adopted in which the liquid was discharged outside the vacuum container via a rotating shaft. Further, in the conventional rotating anode, a pulley attached to a hollow rotating shaft extending outside the vacuum vessel was driven by a belt using an external electric motor. As a result, the device not only becomes larger but also has a more complicated configuration.In particular, it is necessary to apply a vacuum seal to the part where the rotating shaft passes through the vacuum container.
Vacuum leaks and oil leaks were unavoidable, and a decrease in the degree of vacuum caused a decrease in X-ray intensity and abnormal discharge, which were major obstacles to the actual operation of the device. Furthermore, vibrations of the rotating anticathode caused by the belt drive caused variations in the X-ray intensity, making precise X-ray measurement difficult, and other various problems arose.

(Summary of the Invention) An object of the present invention is to provide a high-performance enclosed rotating anode cathode X-ray tube that solves the various conventional problems mentioned above at once and is capable of stable continuous operation over a long period of time. be.

That is, the enclosed rotating anode cathode X-ray tube of the present invention has the following characteristics:
A heat transport liquid is sealed in a rotating body formed by airtightly connecting a hollow truncated conical rotating shaft to at least one surface of a hollow disc-shaped rotating anode, and the heat-transfer liquid is sealed in a rotating body that connects a heating part on the circumferential side of the rotating anode to the hollow rotating body. The rotary body, which acts as a heat pipe due to the convection of the heat transport liquid generated between the heat dissipation section provided on the side surface of the shaft, is suspended and supported within the vacuum container by magnetic bearings, and the electric motor and hollow space that rotate the rotary body are supported. By constructing the heat dissipation section provided on the circumferential side of the rotating shaft by closely opposing a member attached to the rotating body and a member fixed within the vacuum container, a rotational drive mechanism is built into the vacuum container. By eliminating the need for a vacuum seal on the rotating shaft and the need to supply cooling water into the rotating body, highly efficient heat transport is achieved by utilizing the evaporation and condensation of the sealed liquid. It is designed to generate stable X-rays.

(Example) The present invention will be described in detail below with reference to the drawings.

An embodiment of the present invention shown in the drawings is an enclosed rotating anode X-ray tube of the present invention in which the rotary shaft of a heat pipe formed by a hollow rotary anode and a rotary shaft is suspended and vertically supported within a vacuum vessel by a magnetic bearing. This is an example of a specific configuration that is relatively easy to manufacture.

In the illustrated configuration example, a hollow disc-shaped rotating anticathode 3 and a circumferential side of the anticathode 3 are placed in a vacuum vessel 2 that is directly connected to a high vacuum pump (not shown) through a vacuum exhaust port 1. Facing thermionic emission cathode 4
An X-ray extraction window 5 is provided at an appropriate position on the wall surface of the vacuum chamber 2, and an electron beam is projected from the thermionic emission cathode 4 onto the circumferential surface of the rotating anticathode 3, and the electron beam is emitted by the electron impact. The X-rays generated from the incident part are taken out of the vacuum container 2 through the window 5 and used for X-ray diffraction and other X-ray measurements.

A hollow disc-shaped anticathode 3 that emits such X-rays.
In the illustrated example, a similarly hollow truncated conical rotating shaft 6 is airtightly connected to the lower surface of the rotating body, and the rotating body is rotated inside the vacuum vessel 2 by magnetic bearings 7 and 8 provided at its upper and lower ends, respectively. While the bearing is held perpendicular to the body, magnetic force is applied in the three orthogonal axes directions, as is well known and commonly used for this type of magnetic bearing, to support the weight of the rotating body and prevent it from shaking during rotation, as well as to stabilize the circumference of the rotating shaft. It is driven by a high-frequency electric motor, which consists of a disk-shaped rotor 9 attached to the side surface and a coil 10 fixed in the vacuum container 2, which are closely opposed to each other, to rotate at high speed.

Furthermore, a suitable heat transport liquid 16 such as sodium, potassium, mercury, freon, methanol, water, etc. is sealed in the hollow part of the rotating body cathode 3 and the rotating shaft 6, which are airtightly connected to each other. A large number of annular heat-radiating blades 11 are attached to the circumferential side of the vacuum vessel 2, and a large number of annular heat-absorbing blades 12 fixed in the vacuum container 2 are interposed so that they alternately approach each other and face each other, and are supplied into the hollow heat-absorbing blade 12. Pipe 13 and discharge pipe 1
4 is sequentially supplied from the outside through the heat absorbing blades 12 to cool the heat absorbing blades 12, and the high heat generated by the electron impact on the circumferential side of the rotating anticathode 3 is transferred to the convection of the heat transport liquid 16 and the heat radiating blades 11 and the heat absorbing blades 12. The heat radiation is transferred to the cooling liquid and discharged outside the device.

That is, in the enclosed rotating anode X-ray tube of the present invention configured as described above, the rotor 9 and the coil 10
When the rotating anode cathode 3 and the rotating shaft 6 are rotated at high speed by a high-frequency electric motor, the heat transport liquid 16 sealed in the hollow part condenses on the inner surface of the peripheral side part 15 of the rotating anode cathode 3 due to centrifugal force. In such a state, when an electron beam from the electron emitting cathode 4 is applied to the circumferential side of the rotating anticathode 3 to apply an electron impact, powerful X-rays are generated, and at the same time, most of the incident energy is converted to heat and the surrounding The surface of the side portion 15 is heated to a high temperature. The heat transport liquid 16 condensed on the inner surface of the circumferential side portion 15 evaporates due to the high temperature, and the circumferential surface of the rotating anticathode 3 is cooled by the latent heat of evaporation. By the way, since the inner surface of the attachment part of the heat radiation blade 11 on the rotating shaft 6 is cooled by the heat radiation between the heat radiation blade 11 and the heat absorption blade 12 described above, the high temperature vapor of the heat transport liquid is condensed and liquefied here. The heat transport liquid 16 condensed in this manner is again subjected to centrifugal force due to rotation, travels along the inner surface of the truncated conical hollow rotating shaft 6, and condenses on the inner surface of the peripheral side portion 15 of the rotating anticathode 3. Due to the convection of the heat transport liquid 15, the circumferential surface of the rotating anticathode 3 can sufficiently withstand high heat generation due to strong electron impact for generating X-rays without directly introducing cooling water.

As shown in the drawing, a liquid with extremely low vapor pressure is sealed in the lower space 18 of the vacuum container 2, and the lower end of the rotating shaft 6 is immersed in the sealed liquid while being kept at a low temperature with a cooling liquid from the outside. By doing so,
It is also possible to further increase the cooling effect described above.

Further, in the illustrated configuration example, the hollow rotating shaft 6 is connected only to the lower surface of the rotating anode cathode 3, but another similarly configured hollow rotating shaft 6 may also be connected to the upper surface of the rotating anode cathode 3 as described above. It is also possible to further increase the cooling effect.

(Effects of the Invention) As is clear from the following description, according to the present invention, an electric motor is built in the vacuum container of the enclosed rotating anode cathode X-ray tube to rotate the anode, and the rotor is installed in the hollow part of the rotating body. By convection of the enclosed heat transport liquid and heat radiation between the rotating body and fixed parts, the high heat caused by electron impact on the side surface of the anticathode can be efficiently removed using a simple device that maintains a stable high vacuum. Furthermore, by supporting the rotating body within the vacuum container using magnetic bearings, it is possible to eliminate vacuum leaks and oil leaks, and to significantly reduce vibrations associated with rotational drive, making it easy to maintain and manage the equipment. The remarkable effect of this is that it enables powerful, high-performance, and stable long-term continuous operation.

[Brief explanation of drawings]

The drawing is a longitudinal sectional view showing an example of the structure of the enclosed rotating anode X-ray tube of the present invention. 1... Vacuum exhaust port, 2... Vacuum container, 3... Rotating anticathode, 4... Electron emission cathode, 5... X-ray window,
6...Hollow rotating shaft, 7, 8...Magnetic bearing, 9...
Disc-shaped rotor, 10... Coil, 11... Heat radiation blade, 12... Heat absorption blade, 13... Coolant supply pipe, 1
4...Cooling liquid discharge pipe, 15...Anticathode circumferential side, 1
6...Heat transport liquid, 17...Heat transport liquid vapor, 18...
...The space below the vacuum container.

Claims (1)

[Scope of Claims] 1. A heat pipe is constructed by sealing a heat transport liquid 16 in the hollow portion of a hollow disk-shaped rotating anticathode 3 in which a hollow truncated conical rotating shaft 6 with a closed tip is hermetically connected. The heat pipe is held within the vacuum vessel 2 by a magnetic bearing 8 fixed within the vacuum vessel 2 without contacting a fixed part, and a disc attached to the circumferential side of the truncated conical rotating shaft 6. The electron emitting cathode is driven and rotated by a high frequency electric motor consisting of a rotor 9 and a coil 10 fixed in the vacuum container 2 in close opposition to the rotor 9. The peripheral side surface 15 of the rotating anticathode 3 due to the electron impact from 4
The high heat generated above is transferred to the vacuum vessel through at least a heat dissipation blade 11 attached to the circumferential side of the truncated conical rotating shaft 6 and a heat absorption wing 12 fixed in the vacuum vessel 2 in close opposition to the heat dissipation vane 11. 2. An enclosed rotating anode cathode X-ray tube characterized in that it can be removed to the outside. 2. Claim 1, characterized in that a liquid with a low vapor pressure is sealed in the lower space 18 of the vacuum container 2, and the lower end of the truncated conical rotating shaft 6 is immersed therein.
Enclosed rotating anode cathode X-ray tube as described in .