JP2003303563A - Rotary anode-type x-ray tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary anode-type X-ray tube capable of efficiently transferring the heat of an anode target to a cooling medium. <P>SOLUTION: In this rotary anode-type X-ray tube comprising the anode target 11 releasing X-ray, a rotating member 15 and a thrust ring 20 rotated integrally with the anode target, sliding bearings Ra, Rb, Sa, Sb mounted on a fitting part of the rotating member 15 and the thrust ring 20, a rotating supporting mechanism for rotatably supporting the anode target 11 with the rotating member 15 and the thrust ring 20, and a fixed member 16 having a cavity 25 inside thereof to allow the cooling medium to flow therein, the cavity 25 of the fixed member 16 is provided with a cooling medium guide structure 26, and the cooling medium guide structure 26 has a plurality of projecting parts mechanically and thermally face-contacted with a wall face of the cavity 25 at their tip faces, and extended in the direction of the tube axis m. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary anode type X-ray tube incorporated in a medical diagnostic apparatus or the like.

[0002]

2. Description of the Related Art A rotary anode type X-ray tube is an electron tube for generating X-rays. An anode target placed in a vacuum container is rotatably supported by a rotary support mechanism, and an electron beam is emitted to a high speed rotating anode target. The structure is such that irradiation is performed and X-rays are emitted from the anode target. The rotary support mechanism that supports the anode target is composed of a rotating portion and a fixed portion that are fitted to each other, and a bearing portion is provided at the fitting portion of both.

In the bearing portion, a rolling bearing such as a ball bearing or a spiral groove is formed on the bearing surface to form gallium (Ga) or gallium-indium-tin (Ga-).
A dynamic pressure type slide bearing is used in which a liquid metal lubricant such as an In-Sn) alloy is supplied to the spiral groove portion.

When the latter dynamic pressure type slide bearing is used, the respective bearing surfaces of the rotating portion and the fixed portion are opposed to each other over a wide area via the liquid metal lubricant. Therefore,
When the heat of the anode target is released to the outside of the X-ray tube, for example, a method has been proposed in which the heat is transferred from the rotating portion to the fixed portion via the liquid metal lubricant and cooled by a cooling medium or the like flowing in the fixed portion. . An example of this is Japanese Patent No. 182802.
5 and Patent 2983617, Patent 28565
31, JP-A-6-162973, JP-A-7-105.
No. 887 and Japanese Patent Application Laid-Open No. 9-171789.

[0005]

In the conventional rotating anode type X-ray tube, when the heat of the anode target is released, for example, the heat is transferred from the rotating portion to the fixed portion and finally provided in the fixed portion. The structure is such that it is transmitted to the cooling medium flowing through the cooling passage.

In this structure, the amount of heat transferred to the cooling medium increases as the effective contact area with the cooling medium flowing through the fixed portion increases. The effective contact area is the area of the portion of the inner wall surface of the cooling passage provided in the fixed portion where the heat of the anode target is effectively transferred, for example, the portion of the inner surface of the hole forming the cooling passage where the temperature is high.

By design, the temperature T1 on the heat transfer surface of the liquid metal lubricant does not cause a dimensional change due to the mutual reaction between the members constituting the rotating part and the fixed part and the liquid metal lubricant, and stable bearing operation is achieved. Within a range in which the temperature T1 can be maintained and the difference ΔT = T1−T0 between the temperature T1 and the temperature T0 of the cooling medium.
Is within the specified standard range (about 2% of the upper limit when the rejection medium is oil)
Increasing the effective contact area in the range from 00 ° C. to the lower limit of about 150 ° C.) is a standard for improving cooling performance.

However, when miniaturizing the rotary anode type X-ray tube, the outer diameter of the fixed portion becomes smaller, and the inner diameter of the cooling passage provided therein becomes smaller. Therefore, it becomes difficult to secure a large effective contact area.

Further, Japanese Patent Application Laid-Open No. 6-162973 discloses a structure in which a sheet-shaped metal member is brazed to the inner surface of a cavity serving as a cooling passage to increase a contact area with a cooling medium. However, in this method, the contact area between the inner surface of the cavity of the fixed portion and the metal member is small, good heat transfer from the fixed portion to the metal member cannot be obtained, and the cooling efficiency decreases. Also, since it is a method of brazing a metal member,
It is difficult to control the flow of the molten brazing material, and it is difficult to achieve uniform brazing without defects. Therefore, heat transfer varies, and cooling efficiency decreases.

Further, Japanese Patent Application Laid-Open No. 7-105887 discloses a structure in which a sheet-shaped heat dissipation member is brazed to the inner surface of a cavity serving as a cooling passage to increase a contact area with a cooling medium. However, even in the case of this method, Japanese Patent Laid-Open No. 6-16
It has the same drawbacks as the structure of No. 2973.

An object of the present invention is to solve the above-mentioned drawbacks and to provide a rotating anode type X-ray tube which efficiently transfers the heat of the anode target to a cooling medium.

[0012]

According to the present invention, an anode target that emits X-rays, a rotating portion that rotates integrally with the anode target, and a slide bearing are provided at a fitting portion of the rotating portion. A rotation supporting mechanism that rotatably supports the anode target together with the rotating portion,
Rotating anode type X having a fixed part having a cavity inside
In the wire tube, a cooling medium guiding structure is arranged in the cavity of the fixed portion, and the tip end surface of the cooling medium guiding structure is in mechanical and thermal surface contact with the wall surface of the cavity, and the cooling medium guiding structure is arranged in the axial direction of the tube. It is characterized by having a plurality of projecting portions extending.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to the sectional view of FIG.

Reference numeral 11 is an anode target that emits X-rays, and the anode target 11 is connected by a screw 12 to a joint portion 13.
It is fixed to. The joint portion 13 is formed, for example, in a tubular shape as a whole, and includes a small diameter portion 13a having a small outer diameter and a large diameter portion 13b having a large outer diameter. The anode target 11 is fixed to the small diameter portion 13a, and the large diameter portion 13b is connected to the rotation support mechanism 14.

The rotation support mechanism 14 is composed of, for example, a rotating body 15 and a fixed body 16 which are fitted to each other, and a large diameter portion 13b of the joint portion 13 is connected to an outer peripheral portion of the rotating body 15. For example, an annular protruding portion 17 that slightly protrudes is formed on the outer peripheral portion of the rotating body 15.
The inner surface of the large diameter portion 13b of the joint portion 13 is joined to. Further, a space 18 for heat insulation is formed between the inner surface of the large diameter portion 13b of the joint portion 13 and the outer surface of the rotating body 15 except for the joint portion.

The rotating body 15 has a bottomed cylindrical shape, and has a small-diameter portion 15a having a small inner diameter and a large-diameter portion 15 having an inner diameter larger than this.
b, etc., and the cylindrical rotary rotor 19 has a small diameter portion 1
It is fixed to a part of the large-diameter portion 15b so as to surround 5a.
The opening at the lower end of the rotating body 15 in the figure is sealed with a thrust ring 20. The rotating body 15 and the thrust ring 20 are integrally fixed by, for example, a screw 21, and both of them constitute a rotating portion of the rotation supporting mechanism 14. Further, a fixed body 16 is fitted in the internal space surrounded by the rotating body 15 and the thrust ring 20 so as to have, for example, a slight gap during operation.

The fixed body 16 constitutes a fixed portion of the rotation support mechanism 14, and the first small diameter portion 16a having a small outer diameter and fitted to the small diameter portion 15a of the rotating body 15 and the large diameter portion 15 of the rotating body 15.
It is composed of a large-diameter portion 16b fitted to b, a second small-diameter portion 16c penetrating the portion of the thrust ring 20 and extending downward in the drawing. For example, a thread groove is formed on the outer peripheral surface of the lower end of the second small diameter portion 16c in the figure. Further, a dynamic pressure type slide bearing is provided at the fitting portion between the rotating body 15 and the thrust ring 20 and the fixed body 16.

For example, spiral grooves are formed at two locations on the first small diameter portion 16a of the fixed body 16 which fits into the small diameter portion 15a of the rotating body 15, and the dynamic pressure type sliding bearings Ra, R in the radial direction are formed.
b is formed. Also, the large diameter portion 16b of the fixed body 16
Spiral grooves are formed on the upper surface and the lower surface, and dynamic pressure type sliding bearings Sa and Sb in the thrust direction are formed on the step portion of the rotating body 15 and the fitting portion with the thrust ring 20.

These radial dynamic bearings R
a, Rb, and thrust type dynamic bearings Sa,
A liquid metal lubricant is supplied to the gap of the fitting portion provided with Sb during operation.

A first trap 22 is provided outside the second small diameter portion 16c of the fixed body 16. The first trap 22 is fixed to the rotating body 15 together with the thrust ring 20 with a screw 21. The sealing member 23 is fixed to the outer peripheral surface of the second small diameter portion 16c, and the second trap 24 is provided in a part of the sealing member 23. First trap 22 and second
The trap 24 captures the liquid metal lubricant that leaks from the fitting portion between the rotating portion and the fixed portion that configure the rotation support mechanism 14, and prevents the liquid metal lubricant from leaking to the outside. Further, a cavity 25 is formed inside the fixed body 16 and extends along the pipe axis m, for example, the upper end in the figure is closed, and a cooling medium guide structure 26 is fitted in the cavity 25.

The cooling medium guide structure 26 is formed, for example, in a tubular shape as a whole, and a hole 26a for raising the cooling medium, for example, in the direction of the arrow Y1 is formed in the central portion thereof. Is formed with a groove 26b that descends in the direction of the arrow Y2, and a medium passage through which the cooling medium moves up and down is provided.

Here, regarding the cooling medium guide structure 26,
It will be described with reference to FIG. 2 which is a sectional view taken along line aa of FIG.
In FIG. 2, parts corresponding to those in FIG.

The cooling medium guide structure 26 is formed of a metal mainly composed of copper or a copper alloy, for example. A plurality of recessed grooves 31 extending parallel to the pipe axis m are formed on the outer peripheral portion thereof, and a plurality of protrusions 32 are provided between the adjacent recessed grooves 31.
Are formed. The recessed groove 31 is formed, for example, at a predetermined depth with its opposing wall surfaces parallel to each other, and the plurality of protrusions 32 extend parallel to the tube axis m, for example. Tip surface 3 of protrusion 32
2a has a predetermined width W along the circumferential direction of a circle centered on the tube axis m, and each tip surface 32a is located on a common cylindrical surface centered on the tube axis m. And the protrusion 32
The tip surface 32a of the above is fitted to the inner wall surface of the cavity 25 provided in the fixed body 16, and is simultaneously joined by, for example, diffusion joining. At this time, a groove portion 26b (FIG. 1) in which the cooling medium flows is formed in a portion surrounded by the concave groove 31, for example, the wall surface of two adjacent protruding portions 32 and the inner wall surface of the cavity 25.

Next, a method of joining the cooling medium guide structure 26 to the inner surface of the cavity 25 of the fixed body 16 will be described. For example, a cooling medium guide structure formed by plating gold (Au) that functions as a diffusion promoting material on the inner surface of the cavity 25 of the fixed body 16 formed of, for example, an iron alloy or molybdenum alloy, and then formed of a material mainly containing copper or copper alloy 26 is fitted.

In this state, heat treatment is carried out at 750 ° C. for about 30 minutes or longer in a hydrogen furnace or a vacuum furnace.
At this time, for example, the tip portion of the protrusion 32 and the cavity 2
The constituent elements of the inner surface portion of 5 diffuse into at least a part of the diffusion promoting material, and the protrusion 32 and the inner surface of the cavity 25 are diffusion-bonded.
In this case, since the cooling medium guiding structure 26 has a larger coefficient of thermal expansion than, for example, at least the hollow portion of the fixed body 16, the contact surfaces of both of them are brought into close contact with each other at the time of heating, and the pressure necessary for the diffusion bonding is exerted. Diffusion bonding is realized.

In the above structure, the cylindrical rotor 1 is driven by the rotating magnetic field generated by the stator coil (not shown).
9 rotates. This rotational force is transmitted to the anode target 11 and the anode target 11 rotates. In this state, the anode target 11 is irradiated with an electron beam, and the anode target 11 emits X-rays.

When the rotating anode type X-ray tube enters the operating state, the anode target 11 is heated by the collision of the electron beam. This heat is transmitted from the joint portion 13 to the rotating body 15, and further from the rotating body 15 to the fixed body 16 via the liquid metal lubricant, and further to the cooling medium guide structure 26, and the cavity 2 of the fixed body 16 is transmitted.
Emitted by the cooling medium flowing through the five parts.

In the case of the above structure, the cooling medium guiding structure 2
6 is made of a metal having a high thermal conductivity, such as copper,
The tips of the plurality of protrusions 32 are in surface contact with the fixed body 16 mechanically and thermally. Therefore, the cooling medium guide structure 2
6 heats over a wide range at a relatively uniform temperature.
Further, a plurality of protrusions 3 are provided on the outer peripheral portion of the cooling medium guide structure 26.
2 is formed, for example, the cooling medium guiding structure 26 and the cooling medium come into contact with each other over a wide area. Therefore, the effective contact area between the cooling medium guide structure 26 and the fixed body 16 and the cooling medium becomes larger than that in the case of a simple pipe structure, the amount of heat transferred to the cooling medium increases, and the heat dissipation characteristics improve.

Next, as shown in FIGS. 1 and 2, another example of the cooling medium guide structure in which the cooling medium moves up and down will be described with reference to the sectional view of FIG. FIG. 3 shows FIG. 1 and FIG.
The same reference numerals are given to the portions corresponding to, and the overlapping description will be partially omitted.

In the example of FIG. 3, the cooling medium guide structure 26 is formed in a cylindrical shape, and the first hole 36 is formed in the central portion thereof, for example, along the pipe axis. Then, a plurality of second holes 37 having an inner diameter smaller than that of the first holes 36 are provided in an annular shape at equal intervals surrounding the first holes 36. In this case, the cooling medium rises, for example, in the first hole 36 and descends in the plurality of second holes 37. The direction in which the cooling medium flows can be reversed.

Next, another example of the cooling medium guiding structure in which the cooling medium moves up and down will be described with reference to the sectional view of FIG. In FIG. 4, parts corresponding to those in FIGS. 1 to 3 are denoted by the same reference numerals and overlapping description is partially omitted.

In the example of FIG. 4, the cooling medium guiding structure 26 has an outer pipe 38 and an inner pipe 3 arranged in a coaxial structure.
It is composed of 9 and the like. A plurality of intermediate pipes 40 are provided between the outer pipe 38 and the inner pipe 39 in close contact with each other, and in close contact with the outer pipe 38 and the inner pipe 39, and are provided in an annular shape. The inner diameter and the outer diameter of the intermediate pipe 40 are smaller than that of the inner pipe 39. In this case, the cooling medium rises in the inner pipe 39 and descends in the plurality of intermediate pipes 40, for example. The direction in which the cooling medium flows can be reversed.

3 and 4, the fixed body 16 is formed of, for example, an iron alloy or a molybdenum alloy, and the cooling medium guide structure 26 is formed of, for example, copper or a copper alloy, and the inner surface of the cavity 25 of the fixed body 16 is formed. The cooling medium guiding structure 26 and the cooling medium guiding structure 26 are joined by the same method as described with reference to FIGS.

Next, another embodiment of the present invention will be described with reference to FIG.
Will be described with reference to the sectional view of FIG. In FIG. 5, parts corresponding to those in FIG. 1 are denoted by the same reference numerals and overlapping description will be partially omitted.

Reference numeral 10 is a vacuum container constituting a rotary anode type X-ray tube, and in the figure, a part 10a located on the cathode side at one end and a part 10b located on the anode side at the other end are shown. An anode target 11 is arranged in the vacuum container 10,
The anode target 11 is fixed to the joint portion 13. For example, an annular step portion 11a is provided at the edge of the central through hole of the anode target 11, and an outer protruding portion 131 is provided at the upper end of the joint portion 13, so that the step portion 11a of the anode target 11 is provided.
The outer protruding portion 131 of the joint portion 13 is joined to.

The joint portion 13 is connected to a rotary support mechanism 14 that rotatably supports the anode target 11. The rotation support mechanism 14 is composed of a rotating portion and a fixed portion. The rotating portion seals the cylindrical portion 41 and the upper and lower openings of the cylindrical portion 41, for example.
2, the second thrust ring 43, the cylindrical rotor 19 located below the second thrust ring 43, and the like, and the joint portion 13 is connected to the cylindrical portion 41. For example, an inner protruding portion 132 is provided at the lower end of the joint portion 13, an annular protruding portion 41a is provided at the cylindrical portion 41, and the inner protruding portion 132 and the annular protruding portion 41a are fixed by screws 44 and simultaneously diffusion-bonded. ing.

The fixed portion of the rotation support mechanism 14 is a fixed body 16.
Etc. The fixed body 16 includes a large diameter portion 161 that fits into the cylindrical portion 41, a first small diameter portion 162 and a second small diameter portion 163 that are continuous with each other above and below the large diameter portion 161, respectively. Vacuum container 1 is shown at the top
It is fixed at 0a.

For example, a cylindrical first fixing member 45 is airtightly joined to a part of the vacuum container 10a, and a cylindrical second fixing member 46 is provided at a bent portion 45a bent inside the upper end of the first fixing member 45. The second fixing member 46 is airtightly joined, and the cylindrical third fixing member 47 is airtightly joined to the inside of the second fixing member 46.
The upper end of the fixed body 16 in the drawing is airtightly fixed inside the third fixing member 47.

The second small diameter portion 163 of the fixed body 16 penetrates the second thrust ring 43, extends to the outside of the vacuum container 10b, and is hermetically fixed to the vacuum container 10b via the sealing member 48. For example, a thread groove is formed on the lower end of the second small diameter portion 163 in the figure, for example, on the outer peripheral surface located outside the vacuum container 10b. In addition, the fixed body 16 is provided with a cavity 49 penetrating from the upper end surface to the lower end surface in the pipe axis direction,
For example, the cooling medium guide structure 26 is fitted in the cavity 49 of the large-diameter portion 161 and joined by diffusion joining. The cavity 49 and the cooling medium guide structure 26 form a cooling passage through which the cooling medium flows, and the upper and lower ends of the cavity 49 are at the upper and lower ends of the vacuum container 10.
It is open to the outside. At this time, as shown by arrow Y, the cooling medium enters, for example, through the opening 49a at the lower end, passes through the cooling medium guide structure 26, and exits through the opening 49b at the upper end.

Further, the dynamic pressure type sliding bearings Ra, Rb in the radial direction and the dynamic pressure type of the thrust are fitted to the fitting portions of the cylindrical portion 41, the first thrust ring 42, the second thrust ring 43 and the large diameter portion 161 of the fixed body 16. Plain bearing Sa, S
b is formed.

The cooling medium guiding structure 26 of FIG. 5 will now be described with reference to FIG. 6 taken along the line bb in FIG. In FIG. 6, parts corresponding to those in FIGS. 2 to 4 are denoted by the same reference numerals and overlapping description is partially omitted.

The cooling medium guide structure 26 is made of, for example, copper or a metal mainly composed of copper and is solid, and a plurality of concave grooves 31 having a triangular cross section, for example, are formed on the outer peripheral portion thereof. The plurality of recessed grooves 31 extend, for example, parallel to the tube axis m, and a plurality of protrusions 32 that extend, for example, parallel to the tube axis m are formed between adjacent recessed grooves 31. The tip surface 32a of each protrusion 32 has, for example, a predetermined width W in the circumferential direction of a circle centered on the tube axis m, and is located on a common cylindrical surface centered on the tube axis m, for example. There is. The tip surface 32a of the protruding portion 32 is fitted to the inner wall surface of the cavity 49 provided in the fixed body 16 and, at the same time, joined by, for example, diffusion bonding. At this time, a medium passage through which the cooling medium flows is formed in the region of the concave groove 31, for example, in the region surrounded by the wall surface of the adjacent protruding portion 32 and the inner wall surface of the cavity 49.

The inner wall surface of the cavity 49 of the fixed body 16 and the cooling medium guide structure 26 are joined by the same method as in the embodiment of FIG. Also in this case, at least the cavity 49 of the fixed body 16 is formed of, for example, an iron alloy or molybdenum alloy, and the cooling medium guide structure 26 is formed of, for example, a metal material mainly containing copper or a copper alloy.

In the embodiment shown in FIG. 5, both ends of the fixed body 16 are fixed to the vacuum container 10. Therefore, the anode target 11 and the rotation support mechanism 14 are stably supported. Further, dynamic pressure type sliding bearings Ra, Rb, Sa and Sb are arranged on both sides of the anode target 11. Therefore, the balance of the load applied to the upper and lower bearings is improved, and a stable bearing function is realized.

Next, as shown in FIGS. 5 and 6, another example of the cooling medium guide structure in which the cooling medium flows in one direction will be described with reference to the sectional view of FIG. In FIG. 7, parts corresponding to those in FIG.

In this example, the cooling medium guide structure 26 is formed in a columnar shape, and a plurality of holes 71 through which the cooling medium rises are formed inside. In this case, the cooling medium can also be used in a structure in which the holes 71 descend.

Next, another example of the cooling medium guiding structure in which the cooling medium flows in one direction will be described with reference to the sectional view of FIG. In FIG. 8, parts corresponding to those in FIG. 5 are designated by the same reference numerals, and overlapping description will be partially omitted.

In this example, the cooling medium guide structure 26 is composed of an outer pipe 81 having a large diameter which is joined to the inner wall surface of the cavity 49 of the fixed body 16, and the inner space of the outer pipe 81 has a diameter larger than that of the outer pipe 81. A plurality of inner pipes 82 having a small size are arranged in close contact with each other and the outer pipe 81.
In this case, the cooling medium rises in the plurality of inner pipes 82.
Note that the cooling medium may descend the cooling medium guide structure 26.

In each of the above embodiments, the cooling medium guide structure is made of a material mainly composed of copper or a copper alloy. Cooling medium guiding structure has high thermal conductivity, eg 100W at room temperature
It is desirable to use a material having a thermal conductivity of / m · K or more. Further, Au is used as the diffusion promoting material. In addition to Au, a material selected from Cu, Pd, Pt, and alloys containing these metals can be used as the diffusion promoting material.

In the case of FIGS. 2 and 6, the projection of the cooling medium guide structure is formed parallel to the tube axis, for example. However, it is also possible to form the protrusion in a spiral shape extending in the tube axis direction.

According to the above structure, the effective contact area with the cooling medium flowing inside the fixed body is increased, and the heat of the anode target is efficiently transferred to the cooling medium. as a result,
A rotating anode type X-ray tube having a large heat radiation effect can be obtained without increasing the outer shape of the fixed portion.

Further, in FIG. 4 and FIG. 8, the cooling medium guide structure is constituted by a set of a plurality of closely packed pipes. In this case, the area in contact with the cooling medium is larger than that of the single pipe, and the heat dissipation characteristics are improved.

The cooling medium guiding structure shown in FIGS. 2, 3, and 4 has a structure in which the cooling medium reciprocates. However, in these cooling medium guiding structures, if the cooling medium is allowed to flow in all directions in one direction, as shown in FIG. 5, the cooling medium is allowed to flow in one direction inside the fixed body. It can also be applied to wire tubes.

The cooling medium guiding structure shown in FIGS. 6, 7, and 8 has a structure in which the cooling medium flows in one direction inside the fixed body. However, if the passage part through which the cooling medium flows is divided into, for example, two sets, and the direction in which the cooling medium flows is reversed for each set, as shown in FIG. 1, the cooling medium reciprocates inside the fixed body. It can also be applied to X-ray tubes.

[0055]

According to the present invention, the heat of the anode target can be efficiently transferred to the cooling medium flowing inside the fixed body, and a rotary anode type X-ray tube having high cooling efficiency can be realized.

[Brief description of drawings]

FIG. 1 is a vertical sectional view for explaining an embodiment of the present invention.

2 is a cross-sectional view taken along the line segment aa in FIG.

FIG. 3 is a cross-sectional view showing another example of the cooling medium guide structure used in the present invention.

FIG. 4 is a cross-sectional view showing another example of the cooling medium guide structure used in the present invention.

FIG. 5 is a vertical sectional view for explaining another embodiment of the present invention.

6 is a cross-sectional view taken along the line bb of FIG.

FIG. 7 is a cross-sectional view showing another example of the cooling medium guide structure used in the present invention.

FIG. 8 is a cross-sectional view showing another example of the cooling medium guide structure used in the present invention.

[Explanation of symbols]

11 ... Anode target 12 ... screw 13 ... Joint 14 ... Rotation support mechanism 15 ... Rotating body 16 ... Fixed body 17 ... Projection 18 ... Space 19 ... Rotating rotor 19 20 ... Thrust ring 21 ... screw 22 ... First trap 23 ... Sealing member 24 ... Second trap 25 ... Cavity 26 ... Cooling medium guide structure 32 ... Projection of cooling medium guide structure m ... tube axis Ra, Rb ... radial dynamic bearings Sa, Sb ... Dynamic pressure type sliding bearing in thrust direction

Claims (9)

[Claims] 1. An anode target that emits X-rays, a rotating portion that rotates integrally with the anode target, and a slide bearing provided at a fitting portion of the rotating portion, and the anode target together with the rotating portion. In a rotating anode type X-ray tube, which comprises a rotating support mechanism for rotatably supporting the rotating anode, and has a fixed portion having a cavity therein, a cooling medium guide structure is arranged in the cavity of the fixed portion, The rotary anode type X-ray tube, wherein the medium guiding structure has a plurality of projecting portions whose front end surface makes mechanical and thermal surface contact with the wall surface of the cavity and extends in the tube axial direction. 2. The cooling medium guide structure has a first passage formed therein in which the cooling medium flows in the axial direction of the pipe, and the cooling medium is formed by two adjacent predetermined projections and the wall surface of the cavity of the fixed portion. The rotary anode type X-ray tube according to claim 1, wherein a second passage is formed to flow in the tube axis direction. 3. An anode target that emits X-rays, a rotating portion that rotates integrally with the anode target, and a slide bearing provided at a fitting portion of the rotating portion, and the anode target together with the rotating portion. In a rotating anode type X-ray tube, which comprises a rotating support mechanism for rotatably supporting the rotating anode, and has a fixed portion having a cavity therein, a cooling medium guide structure is arranged in the cavity of the fixed portion, The medium guiding structure is characterized in that its outer peripheral surface makes mechanical and thermal surface contact with the wall surface of the cavity, and has a plurality of holes extending in the tube axial direction inside thereof. . 4. A plurality of holes, a first hole extending along a tube axis, and a plurality of second holes arranged around the first hole and having an inner diameter smaller than that of the first hole. The rotating anode type X-ray tube according to claim 3, comprising: 5. An anode target that emits X-rays, a rotating portion that rotates integrally with the anode target, and a slide bearing provided at a fitting portion of the rotating portion, and the anode target together with the rotating portion. In a rotating anode type X-ray tube, which comprises a rotating support mechanism for rotatably supporting the rotating anode, and has a fixed portion having a cavity therein, a cooling medium guide structure is arranged in the cavity of the fixed portion, The medium guiding structure has an outer pipe whose outer peripheral surface mechanically and thermally makes surface contact with the wall surface of the cavity, and a plurality of inner pipes arranged inside the outer pipe. Type X-ray tube. 6. The plurality of inner pipes are arranged between a first pipe extending along a pipe axis and a plurality of second pipes having an inner diameter smaller than that of the first pipe. The rotary anode type X-ray tube according to claim 5, comprising: 7. The rotary anode type X according to claim 1, wherein the material forming the cooling medium guiding structure has a coefficient of thermal expansion higher than that of the material forming at least the hollow portion of the fixed portion. Line tube. 8. The rotary anode type X-ray tube according to claim 1, wherein the cooling medium guide structure is formed of copper or a material mainly containing copper. 9. The rotating anode type X-ray tube according to claim 1, wherein the cooling medium guiding structure and the wall surface of the cavity of the fixed portion are joined by diffusion joining.