JPS5998445A - Rotary anode x-ray tube - Google Patents

Abstract

PURPOSE:To prevent deterioration of magnetic properties by providing coolant flow path in a permanent magnet or in the gap of permanent magnet splitted into plural chips thereby maintaining the permanent magnet for supporting a rotor through magnetic force below Curry temperature. CONSTITUTION:A coolant path 19 in a rotary anode X-ray tube 1 will penetrate through a yoke 11, coils of first and second electromagnets 12a, 12b, 13a, 13b, magnetic poles 11a, 11b, 11c and permanent magnets 10a, 10b. Coolant such as cooling oil will flow along a coolant path 20 and pass through first electromagnets 12a, 12b and magnetic poles 11a, 11c while flow to cover second electromagnets 13a, 13b and manetic pole 11b. Perticularly a flow path 20a is formed in the permanent magnets 10a, 10b to improve the cooling effect.

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention relates to a rotating anode X-ray tube that can support a rotor fixed to a rotating anode in a completely non-contact manner by magnetic force. .

[Prior art and its problems]

A known method for supporting a rotating anode that rotates at high speed in a high vacuum is to support a rotor fixed to the rotating anode by magnetic force instead of using a mechanical bearing.

In a known rotating anode X-ray tube that supports the rotor by such magnetic force, the rotating anode is heated at approximately 12 mm during X-ray irradiation.
Because they are exposed to high temperatures of 00°C, the inner surface of the vacuum case that covers the rotating anode and rotor is made of a material with high heat absorption, and the outer surface of the vacuum case and the magnetic path of the permanent magnet in the magnetic supply device are A coolant passage is provided inside the yoke to improve cooling efficiency.

Here, if we pay attention to the permanent magnet in the magnetic supply device, there is a temperature at which the permanent magnet loses its magnetic properties, that is, a temperature at which it loses its magnetic properties. ℃, 700 to soo'o for rare earth cobalt magnets. Therefore, it is not sufficient to simply circulate the coolant outside the permanent magnet.

[Purpose of the invention]

The present invention has been made to address the above-mentioned problems, and it is an object of the present invention to provide a rotating anode X-ray tube that maintains the permanent magnet at a temperature below one temperature and does not damage its magnetic properties and is more reliable than the conventional one. The purpose is to

[Summary of the invention]

The present invention provides a rotating anode X-ray tube in which a rotor having a rotating anode facing a cathode is supported and rotated by magnetic force in a non-contact manner, comprising: a source of magnetic force installed inside or outside of the rotor; A coolant flow path is provided inside the permanent magnet or in gaps between the permanent magnets divided into a plurality of pieces.

〔Effect of the invention〕

The present invention provides a rotary anode X-ray tube in which a rotor having a rotating anode facing a cathode is supported and rotated by magnetic force in a non-contact manner. By providing this, the cooling efficiency of the permanent magnet, which is essential to the above-mentioned rotating anode X-ray tube, is improved.

[Embodiments of the invention]

Hereinafter, typical embodiments of the present invention will be described using the drawings.

FIG. 1 shows one embodiment of a rotating anode X-ray tube according to the present invention.

The rotating anode X-ray tube (1) shown in the figure consists of a case (2) made of a non-magnetic and insulating material, such as glass, and the inside of this case (2) is maintained at a high vacuum. .

A rotating anode (3) composed of a rotating plate (3a) and a support rod (3b) that supports the rotating plate (3a) is installed opposite to the cathode (4). This support rod (3b) is made of a conductor, has an anode current introducing contact bottle (3c) at its tip, and is connected to a cylindrical rotor (6) through a lid (5) made of an insulating material. ) is fixed. The case (2) is formed to cover the above-described rotating anode (3), cathode (4), and rotor (6). The inner wall of the rotor (6) (
The force has two rings (8a) made of high magnetic permeability material.
, (8b) are spaced apart and played together. Further, the rings (8a), (8a) made of the high magnetic permeability material of the outer wall (9) corresponding to the part located inside the rotor (6) of the case (2),
Ring-shaped permanent magnets (10a) and (10b) magnetized in the radial direction of the rotor (6) are arranged at positions corresponding to gb), and the magnetic paths of these permanent magnets (10a) and (10b) are A yoke is provided so that a yoke can be formed. The cylindrical yoke 0η has four magnetic poles (lla) for the permanent magnet (10a) and four magnetic poles (lla) for the permanent magnet (10b), as shown in FIG. Two magnetic poles (lie) are respectively provided on concentric circles, and the two magnetic poles (lie) are provided on concentric circles.
yoke (
A ring-shaped magnetic pole (llb) is provided at a portion 111. Furthermore, a ring (8a) of said high magnetic permeability material of the permanent magnets (10a), (10b).

(8b) and the rotor (6) of the magnetic flux running through the yoke U.
A first electromagnet (
12a) and (12b) respectively as magnetic poles (lla)
, (llc). Further, a second electromagnet (13a) controls the magnetic flux acting in the direction of the rotation axis of the rotor (6).
, (13b) as the ring-shaped magnetic pole ('l) of the yoke 0υ
1b). The rotor (6) is on the surface of the case (2).
A non-contact first detector (14a) that detects the displacement or speed of the interval between and the case (2) and a non-contact second detector (14b) that detects the displacement or speed in the direction of the rotation axis are provided. 1st. Second electromagnets (12a), (12b), (
13a) and (13b) are controlled by a control device (not shown). A brushless motor is used as a drive device to rotate the rotor (6), and a copper plate/glue (1) is provided on the rotor (6).
The superposition is caused by the stator σe placed outside the . The anode current introduction contact pin (3c) supplies an anode current from the outside via a plate (17) with a spring (17a) provided in the case (2) and a conductive wire (17a) to the rotating anode (3).
). Also, case (2)
A mechanical bearing (1) is installed on the inner wall at a location corresponding to the support rod (3b)
8a) and (18b) are provided.

These mechanical bearings (18a) and (18b) are connected to the rotor (
6) is not used while the specimen is kept in a non-contact state, but is used to hold the rotor (6) in a non-destructive state when not in use or in an emergency.

Note that the AA' cross section and the f3-B' cross section in FIG. 1 are shown in FIG. 2 and FIG. 3, respectively.

The coolant passage ill in the rotating anode X-ray tube (1) configured as described above passes through the yoke 0υ, and
Electromagnets (12a), (12b), (13a), (
13b) coil, magnetic poles (lla), (llb),
(llc) and the permanent magnets (10a) and (10b). This coolant passage is the second
This becomes clear from Figures 3 and 4. That is,
A coolant such as cooling oil flows along the coolant flow path (20) as shown in FIG.
Electromagnets (12a) (12b) and magnetic poles (Ila) (
llc) and further over the second electromagnet (13a) (13b) and the magnetic pole (llb) as seen in FIG. ) (10b) is also formed with a flow path (20a) to enhance the cooling effect.

FIG. 5 shows a cc' cross section in FIG. 4. Here, an arbitrary number of coolant passages (L9) can be installed in an arbitrary position and shape as long as the magnetic force of the permanent magnet (10a) is not impaired.

FIG. 6 shows another embodiment of the invention. Components that are the same as those in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted. In this embodiment, the spacing created by dividing the permanent magnet into several parts is used as a path for the coolant of the permanent magnet. In addition, in order to equalize the magnetic flux of the permanent magnets divided in this way, a ring of high magnetic permeability material (
21). The method of installing a ring made of a high magnetic permeability material on the outer periphery is also effective in the embodiment shown in FIG. 5 for making the magnetic flux somewhat uniform due to the passage 0 spring.

In the coolant passage of the rotating anode X-ray tube configured in this way, the area cooled by the cooling oil can be increased without damaging the magnetic force of the permanent magnet, and the temperature of the permanent magnet can be reduced to a point where the magnet loses its magnetic properties. Efficient cooling can be performed to maintain the temperature below a cucumber.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a rotating anode X-ray tube according to the present invention, and FIG.
Figure 3 shows the AA' cross section and BB' cross section in Figure 1.
4 is an enlarged view of the reservoir showing the coolant passage in FIG. 1, and FIG.
6 is a sectional view showing a modification of the coolant flow path in the rotating anode Xa tube according to the present invention. (1) Rotating anode X-ray tube, (2) Case, (3)
... Rotating anode, (3a) ... Rotating plate, (3b) ...
・Support rod, (3c)...Contact bottle for introducing anode current, (
4)...Cathode, (6), (6a), (6b)
...Cylindrical rotor, (8a), (8b)...
Ring of high magnetic permeability material, (101, (10a), (1
0b) -Permanent magnet, (11), (lla), (ll
b), ・('-11c)-yoke, (12a), (12
b) =-first electromagnet, (13a), (13b)-
Second electricity 8 stone, (14a)...first detector, (
14b)...Second detector, a5)...Copper/G(
drive device) ilfil... Rotator (drive device), (1
η...Contact plate, u...Coolant passage, IZll)
, (2Qa)...Coolant flow path, 12υ...Ring made of high magnetic permeability material. Agent Patent Attorney Nori Sosuke Chika (and 1 other person) Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Scope of Claims] A rotating anode X-ray tube in which a rotor having a rotating anode facing a cathode is supported and rotated by magnetic force in a non-contact manner, comprising: a source of magnetic force installed inside or outside of the rotor; A rotating anode X-ray tube characterized in that a coolant flow path is provided inside a permanent magnet or in gaps between said permanent magnets divided into a plurality of pieces.