JPH1145675A - Rotary anode x-ray tube and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary anode X-ray tube with improved reliability and its manufacture. SOLUTION: A rotary anode X-ray tube has a rotating shaft 15 with a fixed rotary target to generate X-ray, a first rotor 22, which has a bottomed cylindrical shape and is connected with the rotating shaft 15, a second rotor 24 connected to the first rotor 22 and a fixed body 26 located between the first rotor 22 and the second rotor 24. The first rotor 22 is formed of Cu (copper) or a Cu alloy and the rotating shaft 15 and the first rotor 22, and the first rotor 22 and the second rotor 24 are connected by brazing, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a rotating anode type X-ray tube for generating X-rays from a rotating target and a method for manufacturing the same.

[0002]

2. Description of the Related Art A conventional rotating anode X-ray tube will be described with reference to FIG. FIG. 5 shows a rotary target portion of the rotary anode type X-ray tube and a rotary mechanism portion for rotating the rotary target. Reference numeral 51 denotes a vacuum container constituting a rotary anode type X-ray tube, a part of which is shown. A rotary target 52 is arranged in a vacuum vessel 51. The rotating target 52 is fixed to a rotating shaft 53 with a screw 54, and the rotating shaft 53 is connected to a first rotating body 55. The first rotating body 55 has a bottomed cylindrical shape, and the rotating shaft 53 is screwed and connected to a central through hole at the bottom 55 a of the first rotating body 55.

A second rotating body 56 is fixed to a bottom 55a inside the first rotating body 55. The second rotating body 56 is
The rotating shaft 53 rotates on the same axis as the rotating shaft, and an upper end portion 56 a that spreads like a flange is fixed to a bottom portion 55 a of the first rotating body 55 with a screw 57. In addition, the head of the screw 57 is welded to the first rotating body 55 and the screw 57, for example, as indicated by reference numeral A.

[0004] Inside the cylindrical portion 55b of the first rotating body 55, a cylindrical portion of a fixed body 58 is disposed in a space between the first rotating body 55 and the second rotating body 56. Fixed body 58
Is formed in a columnar shape. Further, bearings 59a, at predetermined intervals, between the fixed body 58 and the second rotating body 56,
59b are arranged. The bearings 59a and 59b are fixed by two concentric cylindrical members 60a and 60b, and the bearing 60b located in the lower part of FIG.
8a.

In the rotating anode type X-ray tube having the above-described structure, when a rotating magnetic field is applied from the outside, the first rotating body 55 and the second rotating body 56 rotate, and the rotating target 52 connected thereto rotates. It has a configuration.

[0006]

In the conventional rotary anode type X-ray tube, the anode portion is provided with a rotating target 52 and a rotating shaft 5.
3, the first rotating body 55 and the like. In this case, since the heat of the rotary target 52 is directly transmitted to the rotary shaft 53 for fixing the rotary target 52, a high melting point metal such as W (tungsten), Mo (molybdenum), or an alloy thereof is used. The bottom portion 55a of the first rotating body 55 is made of Fe (iron) or an Fe-based metal. The cylindrical portion 55b of the first rotating body 55 continuous from the bottom portion 55a has, for example, a concentric two-layer structure, in which Fe or an Fe-based metal is used for the inner layer, and Cu is used for the outer layer.
(Copper) and Cu alloy are used.

By the way, a screw 57 for fixing the first rotating body 55 and the second rotating body 56 is provided on the bottom 55a of the first rotating body 55 for joining with the second rotating body 56. 55 or the second rotating body 56, for welding with Fe or F
An e-based metal is used. Since Fe and Fe-based metals have low thermal conductivity, the heat of the rotating shaft 53 is not easily transmitted to the cylindrical portion 55b of the first rotating body 55, and the heat radiation characteristics are reduced.
In addition, the heat of the rotating shaft 53 flows to the bearing 59a via the second rotating body 56, and increases the temperature of the bearing 59a to deteriorate the rotating performance.

Further, the temperature of the joint between the rotating shaft 53 and the first rotating body 55 and the joint between the bottom portion 55a and the cylindrical portion 55b of the first rotating body 55 increase, and the strength of the joined portion is deteriorated. . In addition, Cu or A
Brazing using a brazing material mainly composed of g (silver) is performed. For this reason, when the temperature rises, evaporation deterioration may occur due to the vapor pressure characteristics of the brazing material.

As described above, the conventional rotary anode type X-ray tube sometimes lacks reliability such as low heat radiation characteristics, deteriorated rotation performance, and reduced strength at the joint.

An object of the present invention is to solve the above-mentioned drawbacks and to provide a rotating anode type X-ray tube with improved reliability and a method of manufacturing the same.

[0011]

SUMMARY OF THE INVENTION The present invention provides a rotating shaft on which a rotating target for generating X-rays is fixed, a bottomed cylindrical first rotating body connected to the rotating shaft, and a first rotating body. A second rotating body connected to the body, the first rotating body and the second rotating body,
A rotating anode type X-ray tube including a fixed body positioned between rotating bodies, wherein the first rotating body is formed of Cu or a Cu alloy, and a connection between the rotating shaft and the first rotating body; A rotating anode type X-ray tube, wherein the one rotating body and the second rotating body are connected by brazing.

Further, according to the present invention, there is provided a rotating shaft on which a rotating target for generating X-rays is fixed, a cylindrical first rotating body having the rotating shaft connected thereto, and a rotating shaft connected to the first rotating body. A rotating anode type X-ray tube including a second rotating body, and a fixed body located between the first rotating body and the second rotating body, wherein a connection between the rotating shaft and the first rotating body is provided, and The connection between the first rotating body and the second rotating body is performed by brazing using a Ni alloy as a brazing material.

Further, the first rotating body and the second rotating body are fixed by screws, and the first rotating body and the second rotating body are respectively brazed to the screws.

[0014] Further, the present invention is characterized in that the whirling of the first rotating body is set to 200 μm or less with respect to the axis around which the second rotating body rotates.

The present invention also provides a rotating shaft on which a rotating target for generating X-rays is fixed, a bottomed cylindrical first rotating body connected to the rotating shaft, and a rotating shaft connected to the first rotating body. A rotating anode X-ray tube comprising a second rotating body, and a fixed body located between the first rotating body and the second rotating body, wherein the cylindrical portion of the first rotating body has a cylindrical shape. An opening penetrating the wall of the portion is provided.

Further, a plurality of openings are provided at target positions with respect to an axis around which the first rotating body rotates.

Further, in the method of manufacturing a rotary anode type X-ray tube according to the present invention, the rotation balance of a bottomed cylindrical first rotary body to which a rotary shaft for fixing a rotary target for generating X-rays is connected. Taking a balance, rotating the second rotating body coupled to the first rotating body, rotating the first rotating body, and rotating the balanced second rotating body, And integrating the rotating shaft;
Fixing the rotating target to the rotating shaft integrated with the first rotating body and the second rotating body, incorporating a fixed body between the first rotating body and the second rotating body, and And a step of incorporating a bearing between the second rotating body and the fixed body.

Further, according to the method of manufacturing a rotary anode type X-ray tube of the present invention, a rotary shaft for fixing a rotary target for generating X-rays, and a bottomed cylindrical first rotary shaft to which the rotary shaft is connected. Integrating a body and a second rotator connected to the first rotator, and balancing the rotation of the integrated rotation shaft and the first rotator and the second rotator; A step of fixing a rotation target to the rotating shaft, which is integrated with the first rotating body and the second rotating body and is rotationally balanced, and a fixed body between the first rotating body and the second rotating body. And mounting a bearing between the second rotating body and the fixed body.

Further, the first rotating body and the second rotating body are integrated by brazing.

Further, before the first rotating body and the second rotating body are integrated, a step of fixing the first rotating body and the second rotating body with screws, and a step of fixing the first rotating body and the second rotating body together. The rotating body is integrated by brazing, and at this time, a step of simultaneously brazing the first rotating body and the second rotating body to a screw is provided.

According to the above configuration, the first rotating body is made of Cu
Alternatively, it is made of a Cu alloy, and the connection between the rotating shaft and the first rotating body and the connection between the first rotating body and the second rotating body are performed by brazing. In this case, the rotating shaft, the first rotating body, and the second rotating body that constitute the rotating mechanism are firmly fixed by brazing, and the strength against rotation and the like is improved. In addition, since the first rotating body to which the rotating shaft is connected is formed of Cu or a Cu alloy, heat radiation characteristics are improved.

Also, a Ni alloy is used as a brazing material for brazing the rotating shaft, the first rotating body, and the second rotating body. In this case, since the Ni alloy has high strength at high temperatures and excellent vapor pressure characteristics, sufficient joining strength can be obtained.
In consideration of the above characteristics, the brazing material is N
Among the i alloys, for example, a Ni-P alloy is effective.

When the first rotating body and the second rotating body are brazed to each other, the first rotating body and the second rotating body are fixed in advance by screws. In this case, the first rotating body and the second rotating body can be accurately brazed. By setting the whirling of the first rotating body to be 200 μm or less with respect to the axis around which the second rotating body rotates, it is not necessary to balance the rotation in the air thereafter. Therefore, oxidation of the fixed lubricant can be prevented, and the reliability and life of the rotating mechanism can be improved.

Further, the cylindrical portion of the first rotating body is provided with a plurality of openings penetrating through the wall of the cylindrical portion, for example, at positions symmetrical with respect to the axis around which the first rotating body rotates. In this case, the set screw of the bearing constituting the rotating mechanism can be tightened by using the opening, and the tightening operation is simplified. In addition, since heat of the bearing can be released through the opening, rotation deterioration due to temperature rise can be prevented.

Further, a bottomed cylindrical first rotating body to which a rotating shaft for fixing a rotating target for generating X-rays is connected, or a second rotating body joined to the first rotating body is balanced. The rotation balance of the rotating body is obtained, or the rotation balance is obtained in a state where the rotating shaft, the first rotating body, and the second rotating body are integrated. And then, the rotation axis and the first
The rotating body and the second rotating body are each integrated, or are incorporated in a fixed body or a bearing. in this case,
Since a process such as rework after brazing is not required, assembly is simplified. Further, it is not necessary to adjust the rotational balance in the air. Therefore, oxidation of the solid lubricant can be prevented, and the problem of deterioration in lubricating properties can be solved.
Further, the reliability and life of the rotating mechanism are improved.

In the case where the first rotating body and the second rotating body are fixed with screws, when the first rotating body and the second rotating body are soldered, each of the first rotating body and the second rotating body is screwed together with the screw. They are brazing at the same time. In this case, since the brazing is performed simultaneously, the brazing time is reduced.

As described above, according to the present invention, a highly reliable rotating anode X-ray tube can be realized by improving heat radiation characteristics, mechanical strength, rotation characteristics, and the like.

[0028]

FIG. 1 shows an embodiment of the present invention.
This will be described with reference to FIG.

Reference numeral 11 denotes a vacuum vessel constituting an X-ray tube. A cathode 12 for generating an electron beam is disposed at one end of the vacuum vessel 11, and an anode 13 is disposed at the other end of the vacuum vessel. A rotating target 14 for generating X-rays is provided at a tip portion of the anode 13, and the rotating target 14 is connected to a rotating mechanism 16 via a rotating shaft 15. Also,
A stator 17 is arranged near the anode 13 outside the vacuum vessel 11. The stator 17 generates a rotating magnetic field, thereby rotating the rotating mechanism 15 and further rotating the rotating target 1.
Rotate 4.

Here, the structure of the rotating target 14 and the rotating mechanism 16 will be described with reference to FIG. In FIG. 2, parts corresponding to those in FIG. 1 are denoted by the same reference numerals. Reference numeral 11 denotes a vacuum vessel constituting an X-ray tube, a part of which is shown in the figure. A rotary target 14 is disposed in the vacuum chamber 11, and the rotary target 14
Is fixed with screws 21. The rotation shaft 15 is the first
It is connected to the rotating body 22.

The first rotating body 22 has a cylindrical shape with a bottom.
The whole is made of Cu or Cu alloy. The rotating shaft 15 is screwed into a through hole at the center of the bottom portion 22a of the first rotating body 22 and further brazed. An opening 23 is provided in the cylindrical part 22b of the first rotating body 22 so as to penetrate the wall part. In consideration of the rotational balance of the first rotating body 22, a plurality of openings 23 are provided around the first rotating body 22 symmetrically with the axis, for example, two or nine at intervals of 180 degrees.
Four even numbers are provided at 0 degree intervals. Also, the first rotating body 2
The second rotating body 24 is fixed to the bottom portion 22a inside 2. The second rotating body 24 is located on the same axis as the axis on which the rotating shaft 15 rotates, and has an upper end portion 24 that spreads in a flange shape from the cylindrical portion.
a is fixed to the bottom portion 22a of the first rotating body 22 with a screw 25 and further brazed. The screw 25 is soldered to each of the first rotating body 22 and the second rotating body 24.

The cylindrical portion of the fixed body 26 is disposed in the space between the first and second rotators 22 and 24 inside the cylindrical portion 22b of the first rotator 22. The lower part of the fixed body 26 is formed in a columnar shape. Then, bearings 27a, 27 are provided between the fixed body 26 and the second rotating body 24 at predetermined intervals.
b is arranged. The bearings 27a and 27b are fixed by two concentric cylindrical members 28a and 28b, and the bearing 27b located at the bottom of the figure is a stepped portion 26 of the fixed body 26.
a. Reference numeral 29 denotes a bearing 27
a and 27b.

Here, in the rotating anode type X-ray tube having the above-described structure, the rotating shaft 15, the first rotating body 22, and the second rotating body 2 are used.
4 will be described with reference to FIG. In FIG. 3, parts corresponding to those in FIG. 2 are denoted by the same reference numerals.

The rotating shaft 15 is made of, for example, M
o, W, or an alloy of Mo or W is used, and is screwed into a central through hole at the bottom 22a of the first rotating body 22. The rotation balance of the first rotating body 22 and the second rotating body 24 connected to the first rotating body 22 are independently adjusted in advance. After adjusting the rotational balance, the first rotating body 22 and the second rotating body 24 are fixed with a plurality of screws 25.

Then, as shown by reference numeral A, a vertical annular joint portion between the rotating shaft 15 and the first rotating body 22, and as shown by reference numeral B, the first rotating body 2 including the periphery of the screw 25.
2 and a horizontal annular joint between the second rotating body 24 and a screw 2 which contacts the first rotating body 22
The same brazing material of Ni alloy is arranged around the head of No. 5, and each part is brazed at the same time. In this case, the Ni—P alloy is suitable as a brazing material because it hardly softens at high temperatures.

According to the joining method described above, the first rotating body 2
2 and the second rotating body 24 are screwed in advance before brazing.
Is temporarily fixed. Therefore, the first rotating body 22 and the second
The rotating body 24 can be accurately brazed. Also, the rotating shaft 15
Is directly brazed to the first rotating body 22, the heat of the rotating shaft 15 is immediately transmitted to the first rotating body 22, and the heat radiation characteristics of the rotating shaft 15 are improved. In addition, the first rotating body 22 and the second rotating body 24 independently adjust the rotational balance in advance. Therefore, the first rotator 22 and the second rotator 24 are all in a state where the final machining has been completed. Therefore, if the first rotator 22 and the second rotator 24 are temporarily fixed with the screw 25, accurate brazing can be performed, and the shaft of the first rotator rotates with respect to the axis on which the second rotator rotates, so-called, The whirling of the shaft can be reduced to 200 μm or less. In such a case,
After brazing, it can be assembled as a rotating body without rework. Further, after assembling the rotation mechanism, the rotation adjustment work in the air is eliminated. Therefore, deterioration of the solid lubricant generally used for bearings and the like is eliminated, and rotational characteristics can be improved.

In the above embodiment, the first rotating body 22
Before the first and second rotating bodies 24 are integrated, the rotational balance is independently adjusted in advance. However, as shown in FIG. 4, the rotating shaft 15, the first rotating body 22, and the second rotating body 24 are integrated by brazing, and the target 14 is fixed to the rotating shaft 15. You can also take it. After that, it is combined with the fixed body and the bearing is assembled into the rotating mechanism. Also in this case, there is no need to perform rotation adjustment work in the air after assembling the rotation mechanism. Therefore, there is no deterioration of the solid lubricant used for bearings and the like, and the rotational characteristics are improved. FIG. 4 shows FIG.
3 are denoted by the same reference numerals.

[0038]

According to the present invention, a rotating anode type X-ray tube with improved reliability and a method of manufacturing the same can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic structural diagram illustrating an embodiment of the present invention.

FIG. 2 is a schematic sectional view illustrating an embodiment of the present invention.

FIG. 3 is a schematic sectional view illustrating an embodiment of the present invention, and is a diagram illustrating a method of assembling a rotation mechanism.

FIG. 4 is a schematic cross-sectional view illustrating another embodiment of the present invention.

FIG. 5 is a schematic structural diagram illustrating a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Vacuum container 12 ... Cathode 13 ... Anode 14 ... Rotary target 15 ... Rotating shaft 16 ... Rotating mechanism 17 ... Stator 21 ... Screw 22 ... 1st rotating body 22a ... 1st rotating body bottom 22b ... 1st rotating body cylinder -Shaped portion 23-opening 24-second rotating body 24a-flange-shaped portion of second rotating body 25-screw 26-fixed body 27a, 27b-bearing

Claims (10)

[Claims] 1. A rotating shaft on which a rotating target for generating X-rays is fixed, a bottomed cylindrical first rotating body connected to the rotating shaft, and a second rotating body connected to the first rotating body. A rotating body comprising a body and a fixed body positioned between the first rotating body and the second rotating body, wherein the first rotating body is formed of Cu or a Cu alloy, and the rotating shaft and A rotating anode type X-ray tube, wherein the connection with the first rotating body and the connection between the first rotating body and the second rotating body are each performed by brazing. 2. A rotating shaft to which a rotating target for generating X-rays is fixed, a bottomed cylindrical first rotating body connected to the rotating shaft, and a second rotating body connected to the first rotating body. A rotating anode type X-ray tube including a body and a fixed body positioned between the first rotating body and the second rotating body, wherein a connection between the rotating shaft and the first rotating body is provided; The connection between the rotating body and the second rotating body is made of Ni as brazing material, respectively.
A rotating anode type X-ray tube characterized by being brazed using an alloy. 3. The first rotating body and the second rotating body are fixed with screws, and the first rotating body and the second rotating body are each brazed to a screw. A rotary anode X-ray tube according to claim 2. 4. The rotating anode type X-ray tube according to claim 1, wherein a whirling amount of the first rotating body is set to 200 μm or less with respect to an axis around which the second rotating body rotates. 5. A rotating shaft on which a rotating target for generating X-rays is fixed, a first rotating body with a bottom connected to the rotating shaft, and a second rotating body connected to the first rotating body. In a rotating anode type X-ray tube comprising a body and a fixed body located between the first rotating body and the second rotating body, a wall of the cylindrical part is provided on a cylindrical part of the first rotating body. A rotating anode type X-ray tube characterized by having an opening therethrough. 6. The rotating anode X-ray tube according to claim 5, wherein a plurality of openings are provided at target positions with respect to an axis around which the first rotating body rotates. 7. A step of balancing the rotation of a first cylindrical rotating body with a bottom, to which a rotating shaft for fixing a rotating target that generates X-rays is connected, and a step of connecting a first rotating body to the first rotating body. Balancing the rotation of the two rotating bodies, integrating the first rotating body with the rotating balance, the second rotating body with the rotating balance, and the rotating shaft; Fixing the rotating target to the rotating shaft integrated with the rotating body and the second rotating body, incorporating a fixed body between the first rotating body and the second rotating body, and A method of manufacturing a rotating anode type X-ray tube comprising: a step of incorporating a bearing between two rotating bodies and a fixed body. 8. A rotating shaft for fixing a rotating target that generates X-rays, a bottomed cylindrical first rotating body connected to the rotating shaft, and a second rotating body connected to the first rotating body. A step of integrating the rotating body, a step of balancing the rotation of the integrated rotating shaft and the first rotating body and the second rotating body, and integrating the rotating body with the first rotating body and the second rotating body. Fixing a rotating target to the rotating shaft that has been rotationally balanced by installing a fixed body between the first rotating body and the second rotating body, and interposing a fixed body between the second rotating body and the fixed body. A method for manufacturing a rotary anode type X-ray tube, comprising the steps of: 9. The method for manufacturing a rotary anode X-ray tube according to claim 7, wherein the first rotating body and the second rotating body are integrated by brazing. 10. A step of fixing the first rotator and the second rotator with a screw before integrating the first rotator and the second rotator, and a step of fixing the first rotator and the second rotator to each other. 9. The method according to claim 7, further comprising the step of: brazing the rotators together and, at this time, a step of simultaneously brazing the first rotator and the second rotator with the screw. A method for manufacturing a rotating anode type X-ray tube.