JPS5960949A - X-ray tube device of rotary anode type - Google Patents

Abstract

PURPOSE:To enable a rotary anode to be rotated without contact by supporting it inside radially supporting cylinders and an axially supporting cylinder which are made of a high permeability material and installed independently in the axial direction of the rotary anode while allowing the magnetic fluxes of permanent magnets, installed outside a case, to pass said case. CONSTITUTION:In the axial direction of a rotary anode 3 are provided radially supporting cylinders 16a and 16c and an axially supporting cylinder 16b which are made of a high permeability material. Inside the cylinders 16a-16c, coils 35, 36 and 43 which allow the magnetic fluxes of radially supporting annular permanent magnets 26 and 34 and an axially supporting annular permanent magnet 41, placed outside a vacuum case 1 corresponding to the cylinders 16a- 16c, to pass and produce magnetic attraction fna also regulate these magnetic fluxes, are installed. In addition, a driving motor 18 and displacement detectors 53 and 54 are installed, thereby constituting an X-ray tube device. Owing to such a constitution as above,the rotary anode 3 can be rotated without contact, and a stable regulation can be achieved by preventing any interference among axially and radially supporting forces.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a rotating anode type X-ray tube equipment 161, and in particular, to a rotating anode type X-ray tube equipment 161, in which the rotating anode side is made completely non-contact by a magnetic force supply source installed outside the vacuum container. This invention relates to an improvement in an X-ray tube device that is supported.

[Technical background of the invention]

X-ray tube devices can be categorized based on 41°ζ structure: fixed anode type;
It is broadly divided into two types: rotating anode type. Among these, the rotating anode type is
Since the anode is rotating, the effective area of the heat load applied to the anode can be increased, which has the advantage of being able to withstand instantaneous large loads.

By the way, in a rotating anode type X-ray tube device, in order to protect the anode from heavy loads, it is necessary to rotate the anode as high as possible. In this manner, when rotating the anode at high speed, a lifting platform whose rotating anode side is supported by a mechanical bearing usually has a maximum height of about 180,000 rotations per minute.

Furthermore, when mechanical bearings are used, if an attempt is made to increase the rotational speed to a specified level in a short period of time, a large amount of electric power is required, and the life of the bearings is significantly shortened. Furthermore, there is a problem that the noise caused by the mechanical contact is too loud for medical use.

In order to solve this problem, recently it has been proposed that the rotating anode side is supported in a completely non-contact manner by magnetic force supplied from outside the vacuum vessel. In other words, in this magnetic bearing type device, a cylindrical body made of a high magnetic permeability material is coaxially attached to the rotating anode, and the magnetic force necessary to apply a magnetic bearing force to the cylindrical body outside the vacuum vessel is provided. Permanent magnets and electromagnets for supplying force are arranged to support the cylinder in a completely non-contact manner in both the axial and radial directions.

In this way, in a rotating anode X-ray tube device in which the rotating anode side is supported by magnetic force, the rotating anode side is in a so-called floating form within the vacuum vessel, which reduces energy loss due to friction. There is no such thing, and compared to those supported by mechanical bearings, it is possible to increase the range of g'F rotational speeds, and moreover, it is possible to increase the rotation speed to the specified speed in a short time with low power consumption. I can do it. After cutting, grind it in a vacuum container.
Since the sensor is present, there is no need to worry about noise, and the life of the entire device 6' can be significantly extended.

[Problems with background technology]

However, in the conventional rotating anode type X-ray tube device, there are the following points y and q. In other words, the rotating anode side (
il- In order to support using magnetic force, it is necessary to simultaneously apply an axial magnetic bearing force and a radial magnetic bearing force, but in conventional devices, the magnetic bearing force in both directions is common. It is obtained by the magnetic flux emitted from the permanent magnet.

For this reason, it is difficult to obtain sufficient bearing force in two directions at the same time, and there is a problem in that stable bearing cannot be achieved using only the magnetic force obtained from the permanent magnet.

Also, electricity? i! ; When controlling the magnetic bearing force in two directions simultaneously by energizing the j-stone, it is necessary to perform flilJω1j taking into consideration the mutual interference that occurs, and as a result, the control system becomes complex There were some problems that could not be avoided.

Furthermore, in order to eliminate the above-mentioned problems, it has been considered that one of the magnetic bearing forces is obtained from an electromagnet, but in this case, the electromagnet needs to be constantly energized, which consumes a lot of power. There is a problem.

[Purpose of the invention]

The present invention was developed in view of these circumstances, and its purpose is to use a permanent magnet as the main 51 energy supply source, and to provide the rotating anode side with large magnetic rigidity in both the axial and radial directions. A rotary anode type It is about providing.

[Summary of the invention]

The rotating anode type X-ray tube device according to the present invention combines the 1191+ direction bearing force and the radial bearing force necessary for magnetically supporting the rotating anode side with an axial bearing system and a radial bearing system provided magnetically independently of each other. In particular, λ is provided by a directional bearing system, and a dedicated permanent magnet is used as the main magnetic force supply source for each bearing system.

〔Effect of the invention〕

As mentioned above, since the axial bearing system and the radial bearing system are magnetically independent, the axial bearing force and the radial bearing force can be controlled by selecting the permanent magnet that is the main magnetic supply source for each bearing system. The force can be set arbitrarily depending on the type of force, and both bearing forces can be made sufficiently thick, so it can be supported with large magnetic rigidity in both the axial and radial directions mainly by the magnetic force of the permanent magnet. As a result, magnetic bearings can be realized with extremely low power consumption. Additionally, since both branch systems are magnetically independent, they will not interfere with each other even if both bearing forces are controlled simultaneously. Therefore, the system for performing stabilization control can be simplified.

[Practice of the invention 0] Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, numeral 1 in the figure is a cylindrical vacuum container made of an insulating material, and a cathode 2 is located at the upper part of the vacuum container 1 in the figure.
and a rotary anode 3 formed, for example, in the shape of a disk, are arranged facing each other by a distance of 1 in the vertical direction in the figure.

The cathode 2 is equipped with a filament (not shown) inside. The cathode 2 is located at the tip of a conductor 4 which is provided airtightly through the center of the upper wall of the Makabe container 1 in the figure.

The rotating anode 3 is arranged so that its upper part (1) in the figure always faces the cathode 2 (6'), and as it approaches the outer periphery, the upper surface of the peripheral part is arranged 6' to obtain the desired X-rays. It is formed with a perfect tapered surface. The rotating anode 3 is supported by a rotor 1, which will be described later.

Therefore, the rotating anode 30 is
In the part facing the lower surface in the figure, a recessed wall 5 is formed which is recessed in a cylindrical shape with a bottom by an amount of yB toward the rotating inner rod 3. In the so-called bottom wall medium heating section, an inner recessed wall 6 is formed in which the central portion is recessed concentrically with the recessed wall 5 and opposite to the rotating anode side (towards pi). Then, the above-mentioned recessed wall 5 and a position 1 on the outside thereof are provided.
A rotor 1) is rotatably housed in a cylindrical space 8 formed between the inner cylindrical wall 7 and the inner recessed wall 6.

The rotor 1 has two main parts: it is disposed coaxially with the rotating anode 3, and its upper end in the figure is connected to the center of the lower surface of the rotary anode 3 in the figure, and its lower end in the figure is connected to the inner recessed wall 6. Hiron'ffi inserted into the cavity surrounded by, sexual auxiliary axis 12
It is composed of a cylindrical main body 14 whose upper end in the figure is connected to the auxiliary shaft 12 via the annular insulating material 3, and whose lower end in the figure is fitted into the cylindrical space B. There is. The rotor body 14 has an outer diameter smaller than the inner diameter of the wall portion 7;
Further, a cylindrical support frame 15 made of non-magnetic material or paramagnetic material and having an inner diameter larger than the outer diameter of the recessed wall 5;
Annular grooves 16a, 16h, 16c are formed in three stages in the axial direction on the inner peripheral surface of the support frame 15, and these annular grooves 1
Cylinders 17 a + 17 b + 17 c made of a high magnetic permeability material are mounted inside 6 a, 16 b, and 16 c, and a motor 18 is fixed to, for example, the center of the outer peripheral surface of the support frame 15.
and the rotor 19 (11).

Further, on the inner surface of the inner recessed wall 6, bearings 21a and 21b are provided to mechanically support the auxiliary shaft 12 only in an emergency.
At all times, the above auxiliary IHB 12 is called non-contact B.
', is provided in Section I. Furthermore, a concave spherical surface is formed on the lower end surface of the auxiliary shaft 12 in the figure, and a contact ball 23 is disposed in a position opposite to this spherical surface 22 so as to be rotatably housed in the case. These contact balls 23
and the spherical surface 22 constitute an inner rod current introducing device.

The case is electrically connected to the tip of a conductive rod 25 that hermetically penetrates the so-called bottom wall of the inner recessed wall 6 via a spring 24f.

Therefore, in the space surrounded by the recessed wall 5, from the upper part to the lower part in FIG.
The magnetic bearing element 26 forming the longitudinal bearing system and the front Be=
'jF! ] A magnetic bearing groove 27 forming an axial bearing system with the body Z7b and a magnetic bearing element 28 forming a radial bearing system with the complement 17c are made of non-magnetic material. It is installed for the same purpose with spacers 29 and 30 interposed therebetween. The magnetic bearing elements 26 and 28, which constitute the radial support system with the cylinders 17m and 17c, are similar to each other (E
H is formed, and the fiji-shaped part 3) and this cylindrical part 3
81 toward the outer circumference of one end of 1! , as shown in Figure 2, magnetic poles 32a, 32 are integrally protruded with an opening angle of 90 degrees.
A magnetic pole material 33 consisting of b, 32c, and 32d is attached to the outer periphery of the cylindrical portion 3 and is oriented in the radial direction as shown by the illustrated polarity. A ring 35 made of a high magnetic permeability material is attached to the outer periphery of the annular permanent magnet 34, and a radial stabilizer is attached to the outer periphery of each of the magnetic poles 32a to 32d. Coil 36a, 3 for north side 1jtl
6b +36c, ,? It is composed of 6 d. The length of the magnetic pole material 33 in the axial direction is set to be approximately the same as that of the cylindrical body 17a. On the other hand, the cylinder 1
The magnetic support element 27, which together with 7b constitutes an axial support system, is
A magnetic pole material 40 consisting of a cylindrical portion 38 and magnetic pole portions 39a and 39b integrally provided in a ring shape at both ends of the cylindrical portion 38, and a device f provided on the outer periphery of the central portion of the cylindrical portion 38 with the illustrated polarity. As shown, four annular permanent magnets magnetized in the radial direction,
A ring 42 made of magnetically permeable material is attached to the outer periphery of the annular permanent magnet 4, and between the magnetic pole part 39a and the annular permanent magnet 41, and between the fa pole '1 [S 39b and the annular permanent magnet 41].
The coils 43a and 4.3b for the axial stabilization section 101 are installed between the axially stabilizing coils 43a and 4.3b. The length is set to be approximately the same as the axial length of the cylindrical body 17b.

Therefore, on the outside of the wall 7 of the front ML vacuum container 1, there is a front body formed in a bottomed cylindrical shape of a non-magnetic material or a paramagnetic material with a predetermined gap 51 between the wall 7 and the wall 7. 52 is installed. Then, to the magnetic poles of the magnetic bearing elements 26 and 28 at the upper and lower parts of the figure in the gap 5], ? 2 a~32
As shown in FIG. 2, a displacement detector 53 for detecting the position of the rotor body J4- in the direction orthogonal to the axial direction is provided near the position fg opposite to the rotor body J4-. 1. Displacement detection 2+v 54 for ejecting is also provided.

Further, a stator 20 of the motor 18 is attached to a position 11t in the upper iEc space 51 facing the front ML rotor 19. The armature winding of the stator 20 is ′
- Connected to the power supply for driving the motor, which is not shown in the figure, and the output terminal of each displacement detector 53 and 54 is connected to the rotor stabilization 11il.
It is connected to the J fiiU device 6. The rotor stabilization 1ulJ control device 61 is actually divided into two types: one for stabilization in the radial direction and the other for stabilization in the axial direction.
q, and both are equipped with a known positioning guide 11i.
The control system is comprised of one that implements the lJ 1lilJ control method and one that implements the known cover balance control method. now,
One of the methods for realizing the radial cover balance control method is as shown in FIG.
2. Power the signal amplification device 63, the power amplification device 64,
This power amplification cage 64 is located between the displacement detectors □
ml, 6, corresponding to the value obtained by changing the magnetic gear lug length twice and once in the same machine, in the coil for radial stabilization control.
A current containing ff is supplied in a direction that increases the magnetic flux to those located in the direction where the magnetic gear lug length increases, and a current containing dJ is supplied to those located in the direction in which the magnetic gear lug length decreases. We are trying to supply it. The output of the axial displacement detector 54 is also processed on the same principle; 65 in FIG. 1 indicates an X-ray transmission window.

With such a configuration, the magnetic flux emitted from each permanent magnet 34 of the magnetic bearing elements 26° 28 and the magnetic flux emitted from the four permanent magnets of the magnetic bearing element 27 follow the path X1lX2+Y1+Y2 shown by the broken line arrow in FIG. through which it is provided for radial and axial bearing. That is, the magnetic flux emitted from the permanent magnet 34 of the magnetic bearing element 26 enters the cylindrical body 17m from its inner surface at a right angle, and after traveling in the axial direction inside this cylindrical body 17a, the magnetic flux is a +3), a pole J', ? 3 magnet IFIJA 32
It takes a route that returns to the permanent magnet 34 via a r 32br32c and 32d. Therefore, magnetic bearing element 2
A magnetic attraction force in the radial direction t between 6 and the cylinder 17a,
A (d) air bearing force acts in the radial direction of the tab. The magnetic flux emitted from the permanent magnet 34 of the magnetic bearing element 28 similarly follows the path X2. Therefore, the relationship between the magnetic bearing element 28 and the cylindrical body 17c On the other hand, the magnetic flux emitted from the permanent magnet 4) of the magnetic bearing element 27 enters the central part of the cylindrical body 17b at a right angle to ``11''. After advancing in the axial direction inside the cylinder 17b, the magnetic pole part 39a of the magnetic pole material 40 is
, 39b and return to the permanent Ippa stone 4 through two routes Y lr Y z. Then, magnetic bearing element 2
There is an axial magnetic attraction force between 7 and the front body 17b.
Therefore, a magnetic bearing force in the axial direction will act.

Therefore, the rotor 1 is supported with a large supporting force in both the radial and axial directions by the magnetic flux supplied from the permanent magnets 34 and 41.

At this time, the position of the rotor is adjusted by the rotor stabilization control device 61 described above so as to balance the magnetic bearing force with the external force applied to the rotor. Then, when the balance is achieved, the operation of the rotor stabilization control device steam 61 is stopped. Therefore, the rotor 11 is connected to the permanent magnet 34.4.
Completely non-contact state due to the magnetic bearing force of 1.
It is supported in a floating state. In this state, the motor 18
When a power source is connected to the stator 20 of the rotor 19, the rotor 19 rotates, and accordingly, the rotor 11 to which the rotor 19 is attached starts rotating. Therefore, the rotating anode 3 also starts rotating. Then, when the rotor 1 reaches the specified rotation, the axial stabilization 1tll ('ill coil 43a) is activated.

When a signal is applied to the rotor 43b and the rotor position 1ζ1' is moved axially toward the purpose of i1i, the anode current control device is brought into contact with the rotor, the potential difference between the rotating anode 3 and the cathode 2 becomes large Electrons generated at the cathode 2 collide with the rotating anode 3,
As a result, X-rays P are emitted as shown by arrows in FIG. Therefore, the function of the rotating anode type X-ray tube R1 is exhibited here. And x it
i When not irradiated, the coils 43a, 4, ? The energization of b is released and the motor power is cut off. At this time, the rotor 1) is supported in a high vacuum in a completely non-contact manner, so there is no attenuation of the rotational speed due to friction, and the magnetic bearing force at this time is 11, 34.41 Therefore, it is possible to constantly maintain rotation with extremely low power consumption, and therefore, X-rays can be irradiated at any time with minimum waiting time.

In this way, the axial bearing system and the radial bearing system are provided magnetically independently, and a permanent magnet is used as the main source of magnetic force for each bearing system. therefore,
The axial bearing force and the radial bearing force can be arbitrarily set separately by selecting permanent magnets, etc., and both bearing forces can be made sufficiently large. It can be supported with high magnetic rigidity in both axial and radial directions using only air force, resulting in extremely low consumption.
IJ'l, 'Magnetic support can be realized by force.

Furthermore, since both bearing threads are magnetically independent, they do not interfere with each other even when both bearing forces are controlled simultaneously.

Therefore, the system for performing stabilization control can be simplified.

Note that the present invention is not limited to the embodiments described above. That is, in the embodiment described above, the rotor is located inside each magnetic bearing element, but there is no problem even if this relationship is reversed.

1. Although the cooling means is omitted in the embodiment, cooling may be provided from outside the vacuum container. Anode electrode v
The IL shearing and inserting device i> is not limited to that of the embodiment, but may be any device that exhibits good electrical characteristics and wear resistance during operation.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of a main part of an X-ray tube device according to an embodiment of the present invention, and FIG.
Cut along ij 11Jr A sectional view seen in the direction of the L arrow, Figure 3 is a cross-sectional view of the interior f6゛ cut along the line BB in Figure 1, 1 mr u'J' seen in the direction of the L arrow The r-plane view and FIG. 4 are diagrams for explaining the passage path of magnetic flux in the same device. 1... Vacuum vessel, 2... Cathode, 3... Rotating anode,
5...Concavity Q, 'y, 11...Rotor, 14...
Rotor body, 17a, 17b, 17cm cylinder, I 8
...Motor, 26.27.28...Magnetic bearing element.

Claims (1)

[Claims] A rotating anode type X-ray in which a cathode and a rotating anode are placed facing each other in a vacuum container, and the rotating anode side is magnetically supported in a completely non-contact state by a magnetic force supply source provided outside the vacuum container. In the tube device, a radial support cylinder and an axial support cylinder made of a high magnetic permeability material are provided axially connected to the rotating anode, and each cylinder is fitted to the outside of the vacuum vessel. The annular permanent magnets for radial support and the annular permanent magnets for axial support are arranged in such a relationship that the magnetic fluxes emitted from these nine annular permanent magnets are passed through the respective corresponding cylindrical bodies in the axial direction and returned. a magnetic pole material that applies a radial magnetic attraction force to the radial support tube and an axial magnetic attraction force to the axial support tube by guiding the magnetic pole materials along a path; A rotating anode type X-ray tube device comprising a plurality of coils installed so as to control passing magnetic flux.