JPS625546A - Rotary anode type x-ray tube apparatus - Google Patents

Abstract

PURPOSE:To strengthen a rotating body to a centrifugal force by rotating it on the non-contact basis after fixing both ends of target to a shaft consisting of electric insulator and providing a bearing part which becomes a magnetic gearing to the external circumference of the respective electric insulator. CONSTITUTION:The both ends of target 4 which is rotary anode are fixed to the flange part of shafts 137, 145 consisting of electrical insulator through a heat insulator ring 138-a and a metal plate 138. The rotors 114, 115 for magnetic bearing are attached by the shrinkage fit to the external circumference of the insulated shafts 137, 145 and said target can be supported on the non- contact basis by the stators 110, 111 for radial magnetic bearing and the stators 112, 113 for thrust magnetic bearing. Moreover, the rotor 115 is attached to the external circumference of the insulated shaft 145, forming an induction motor in combination with the stator 134, thereby realizing rotation thereof. Accordingly, rigidity at the magnetic bearing part and rotating part can be made very large, super-high speed rotation can be realized with low vibration and the operation life can also be improved.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a rotating anode type X-ray tube device, which rotates at high speed while supporting an anode target in a non-contact manner with a magnetic bearing. supplying a high voltage of This invention relates to a rotating anode type X-ray tube device with a compact structure.

[Technical background of the invention]

Generally, X-ray tubes are used for medical purposes, for example, for X-ray diagnosis, and in the case of stomach examinations, etc., an X-ray tube as shown in FIG. 3 has been conventionally used. This X-ray tube is of the so-called rotating anode type, in which a cathode 2 is disposed on one side of an envelope 1, and a cathode 3 containing a cathode filament that emits thermionic electrons and a focusing electrode is provided eccentrically. There is. Further, near the center of the envelope 1, a substantially umbrella-shaped anode target 4 is arranged opposite to the cathode structure 2. This anode TARDAT 4 provides a high potential difference with the cathode structure 2, accelerates electrons emitted from the cathode filament, causes them to collide, and generates X-rays by bremsstrahlung radiation.
It is designed to store and dissipate the large amount of heat generated at this time, and is designed to rotate at high speed in order to effectively expand the heat generation area. Such an anode target 4 is connected to a covered cylindrical rotor 6 via a support column 5. The rotor 6 generates rotational force by receiving a rotating magnetic field generated by a stator 7 disposed outside the envelope 1, and together with the stator 7 forms an induction motor. Note that the support column 5 and the rotor 6 are integrated. A rotating shaft 8 is disposed inside the rotor 6 along the axial center,
One end of this rotating shaft 8 is fixed to the rotor 6 with a screw or the like (not shown). This rotating shaft 8 and the rotor 6
A bottomed cylindrical stator 9 is disposed coaxially between the stator 9 and the stator 9, and one end thereof is fixed to the envelope 1 via sealing rings 10 and 11. A portion of the stator 9 is exposed outside the tube, and also serves to support and fix the entire X-ray tube to the outside. Bearings 12, 13 are interposed between the stator 9 and the rotating shaft 8, so that the rotating shaft 8 can rotate freely. Now, during operation, when the electrons emitted from the cathode filament reach the target 4, the power output reaches 1 kW when the anode voltage is 50 kV and the current is 20 mA.

Since more than 99 degrees of this power is converted into heat, the target 4 is heated to a high temperature with heat radiation to the outside and heat conduction to other parts. Thermal radiation increases in proportion to the fourth power of temperature, so as the temperature rises, heat radiation increases significantly and thermal equilibrium is reached in a short time. For example, under the above conditions, equilibration occurs at 1100°C after 5 minutes. On the other hand, when the other end of the conductive medium is thermally free, heat transfer by thermal conduction takes a long time and the end gradually becomes hotter. The heat of the target 4 is then transferred to the rotor 6 and rotating shaft 8, making them high temperature. When the rotor 6 becomes high in temperature, thermal radiation increases and thermal equilibrium is reached as described above. Under the above conditions,
The 0 point on the support column 5 is 800° C. approximately 15 minutes after the start of energization, the 0 point on the rotor 6 is 550° C. 30 minutes after the start of energization, and the 0 point near the bearing 13 starts energizing.

After about 50 minutes, thermal equilibrium is reached at 400°C. bearing 1
If the heat conduction of point 3 deteriorates, the temperature at point 0 will reach 550° C., which is almost the same as point 0. bearing 1
Depending on the rotational condition of the goal in 2.13, thermal expansion may cause poor clearance between the outer ring and the inner ring, resulting in problems such as bearing damage. Furthermore, if the temperature of the bearings 12, 13 exceeds 500° C., the hardness of the goal may decrease, causing damage to the tube such as stopping rotation. Furthermore, when the rotor 6 and target 4 are rotated through the bearings 12 and 13 in a vacuum, it has been found that if the rotation speed is increased, the rotation life is extremely reduced. The Xls tubes actually used are io and oo.

rpm, but even in this case the rotational life is not sufficient.

Furthermore, when the heat capacity and t of the target 4 increase, the weight of the target increases, which has the disadvantage of shortening the rotational life. In order to solve this problem, magnetically levitated X
Although wire tubes have been proposed, they have the following drawbacks.

Specifically, in U.S. Pat. No. 4,417,171, the outer diameter of the rotor is extremely large, which not only increases the size of the entire X-ray tube, but also requires high voltage to be applied to the central pillar, making it difficult to maintain it. Have difficulty. Tokuko Sho 58-438
No. 60 has the disadvantage that the rotor and target have low rigidity, the resonance frequency is low, and high speed rotation is not possible.

In Japanese Patent Application Laid-Open No. 59-63646, the anode must be kept at ground potential, which is inconvenient as a special high voltage power supply and high voltage cable are required.

[Problems with background technology]

However, conventional X-ray tubes like the one described here have the following drawbacks. In other words, the inner ring of bearings 12 and 13 tends to reach high temperatures, but the outer rings are at low temperatures. Change. As mentioned above, when the temperature of the 2-ring of the bearing 12.13 increases, not only will the clearance between the goal and the inner and outer rings become insufficient, but the lubricant existing between them will evaporate, causing the bearing 12. .13 may be damaged. For these reasons, there is a drawback that rotation stoppage accidents tend to occur frequently. In order to prevent this, increasing the degree of blackening of the target 4, increasing the degree of blackening of the surface of the rotor 6, and installing a heat shield plate between the target 4 and the rotor 6 have been considered, but these effects are The actual situation is that the amount of power entering the target 4 is relatively small.

In addition, when this structure is rotated at high speed, the rotational life becomes extremely short. And if we increase the heat capacity of target 4,
Since the weight of the target 4 increases, its rotational life becomes increasingly short. In order to eliminate these problems, a rotating anode type X-ray tube using a magnetic bearing has been developed as described in US Patent Specification 4.
417,171, Japanese Patent Publication No. 58-43860, and Japanese Patent Publication No. 59-63646. however,
Each of these has drawbacks as described above.

[Purpose of the invention]

The purpose of this invention is to rotatably support a large-capacity X-ray generating tarp using a magnetic bearing without contact, to maintain sufficiently high rigidity of the magnetic bearing, and to increase the rigidity of the rotating part. High resonance frequency enables ultra-high speed rotation with low scratching, extremely long rotation life, target at positive high voltage, cathode at negative high voltage, rotor and stator of vacuum vessels and magnetic bearings. By keeping the magnetic gear substantially at ground potential, the magnetic gear is made smaller and more rigid, and the reliability of the rotating anode is significantly improved by preventing noise from entering the position sensor that detects the displacement of the rotor. An object of the present invention is to provide a type X-ray tube device.

[Summary of the invention]

In this invention, an insulator is inserted and fixed inside a rotor for a magnetic bearing, and an X-ray generation TARDAT is mechanically fixed at a position separated in the axial direction of the insulator via this insulator.
The target and the magnetic bearing rotor are electrically insulated by the separated insulating part, the magnetic bearing rotor is maintained at substantially ground potential, and the target is provided by penetrating the inside of at least one rotor. It is configured to supply a positive high voltage to the target from outside the tube through the conductive path. A negative high voltage can be applied to the cathode, and it can be used with the same high voltage power supply with the same neutral point grounding as a conventional rotating anode X-ray tube, and the same level of power as a conventional X-ray tube. It is a rotary anode type X-ray tube device that can rotate a large-capacity tarp at an ultra-high speed, has an extremely long life, and has low vibration and noise.

[Embodiments of the invention]

The rotating anode type X-ray tube device of the present invention is constructed as shown in FIG. 1, and the same parts as in the conventional example (FIG. 3) are given the same reference numerals.

That is, the central portion of the housing 1, which is a vacuum container, is made of metal and is maintained at ground potential. The housing 1 includes an endothermic container part 101 that absorbs heat from the target 4 for generating X-rays, and a vacuum partition wall 1oz, xo in the magnetic axis hall.
's, vacuum partitions 104 and 105 within the position sensor, auxiliary bearing support plates 106 and 107, and end container 108.
, 109. Such a housing 1 forms a vacuum container as described above with the above-mentioned parts,
Its interior is kept at a high vacuum.

Radial magnetic bearing stators zxo and xxx that generate an attractive force in the radial direction are provided outside the vacuum partition walls 102 and 103 in the magnetic shaft hall. Thrust magnetic bearing stators 112 and 113 that generate an attractive force in the thrust direction are provided beside the radial magnetic bearing stators 110 and 111, respectively.

Inside each of these stators is a magnetic bearing rotor 1.
14 and 115 are arranged. This Wi air shaft bearing rotor 114115 is made of a magnetic material such as pure iron, and its outer periphery is covered with laminated plates 116 and 117 made of magnetic material. 111 to generate a suction force to form a radial magnetic bearing.

Further, at the ends of the magnetic bearing rotors 114 and 115, for example, a barium inbrecathode is inserted through heat-resistant cylinders 118 and 119 made of a thin heat-resistant metal such as tantalum or a ceramic such as Si3N4 with a metalized surface. Cathodes 120 and 121 operating at low temperatures are attached, and current-carrying diodes 124 and 125 are formed with heaters 122 and 123 for heating.

Further, fixed cathodes 126 and 127 are provided in the vicinity thereof, and current-carrying diodes 128 and 129 having characteristics opposite to those of the current-carrying diodes 124 and 125 are formed between the fixed cathodes 126 and 127 and a part of the rotating heat-resistant cylinder 118 and 119. are doing.

With these diodes, the rotor 11 for Wi air shaft bearing
4115 are both kept substantially at ground potential, and have substantially the same potential as the magnetic axis internal vacuum partition walls lθ2 and 103. Therefore, the distance between them can be kept within 0.5 m, and the stator 110, 111 for the radial rupture bearing and the rotor 114° 1 for the magnetic bearing can be kept at a distance of 0.5 m or less.
15 can be reduced to within one inch. As a result, the bearing rigidity fci can be increased.

Furthermore, metal rings 130 and 131 made of a non-matrix metal are fixed to the outer periphery of the magnetic bearing rotors 114 and 115 following the laminate plates 116 and 117, and metal rings 130 and 131 made of non-matrix metal are fixed to the outer periphery of the rotor 115. Subsequently, a copper ring 132 and a non-magnetic ring 133 are fixed. A stator 134 for rotating the rotor is provided on the outside of the steel song 132, and these form an induction motor to rotate the rotor at high speed. Radial sensors 135 and 136 are provided on the outside of one end of the rotor via rings 104 and 105, respectively, to detect the deflection of the magnetic bearing rotor 114 and 115.

Furthermore, a penetrating electrical insulator 137 is mechanically and rigidly fixed to the inside of the magnetic bearing rotor 114 by shrink fitting or the like. A metal plate 138 made of molybdenum or the like is bonded to an end surface 137-* of the electrical insulator 137 on the TARDAT side of the rotor 114. This joining can be achieved by brazing or the like. And, this metal plate 13gVC is an anode target 4 for X-ray generation.
The end flange 41 of the cylindrical support body is mechanically and tightly fixed by a gel 139 via a heat insulating ring 13B-*t- made of ceramic, glue, or the like.

The end of the magnetic bearing rotor 114 and the metal plate 13
In the middle part of B, an insulating cylindrical part 137-b is formed in which the diameter of the electric insulator 137 is larger than that of other parts, and the target 4 and the magnetic bearing roller 114 have a high withstand voltage (for example, 8
0 kV or higher). In this case, electrical insulator 1
The insulating cylindrical portion 137-b of No. 37 has a bent structure on the surface to increase the creepage distance.

A thin conductive sleeve 1140 is provided on the inner peripheral surface of the central hole of the electrical insulator 137, and i! The unconscious object 137 is electrically coupled to the target 4 via a conductive film 141 and members 138 and 139 attached to the end face of the target 4 by metallization or the like. A heat-resistant cylinder 142 is provided at the other end of the conductive sleeve 140, a thermionic emission cathode 143 is attached to a part of the cylinder, and a N-electrode 143 is heated to about 1000°C by a heater 144 attached to the outside. Heated to high temperatures. Above heater 1
44, high voltage (e.g. 75kV) is applied from outside the tube during operation.
is applied, and the inflow of thermionic electrons from the heated cathode 143 as described above results in electrical coupling with low impedance. The perveance of the diode composed of the cathode 143 and the heater 144 is /? of the diode composed of the cathode 3 and target 4. -Since it is larger than the bias, the 1 pressure drop in this part is smaller. Therefore, a high voltage can be supplied to the tarpaulin 4 from outside the tube in a non-contact manner.

Also in the inner part of the other mother air bearing rotor 115,
An electrical insulator 145 is inserted and fixed by shrink fitting or the like, and the same as above.

The rotor 116 and the metal plate 138 for mounting have a high withstand voltage (e.g. 80k
V). As described above, the rotor 115 is kept at the ground potential, and the target 4 is kept at a high positive voltage. Note that the insulating cylindrical portion 145-* is provided with a bent structure portion to increase the creepage distance.

Further, a negative high voltage (for example, -73 kV) is applied to the cathode 3 from outside the tube through a conductor (not shown) via the bushing 148.
is supplied, and thermionic electrons are applied to a positive high voltage (
For example, the X-ray beam 146 is generated by colliding with the target 4 maintained at +75 kV). This X-ray beam 146 passes through the entire X-ray emission window 147 made of, for example, beryllium and is attached to the heat-absorbing container section 101, and is irradiated to the outside of the tube. In addition, secondary electrons (not shown) emitted from the target 4 are shielded by shielding plates 148 and 149 provided inside the tube, and the insulating cylindrical portions 137- of the electrical insulators 137 and 145
b.

It prevents it from flying into 145-*. Further, a heating voltage and a high voltage are supplied to the heater 144 from outside the tube via a bushing 145.

Further, auxiliary bearings 150, 151 are provided on the outer sides of the ends of the rotors 114, 115, respectively, on support plates 106, 1.
07, it is strongly supported and non-contact, but before operation or in case of abnormal operation, this auxiliary bearing 150,1
The rotating part is supported by 51.

Further, a position sensor 152 is attached to the end of the rotor 115 to detect deviation in the thrust direction, and its output is used to detect the stator 12 for air bearings.
, I J Jtl'' to control the position in the thrust direction.

Note that it is preferable to use ceramic or clay such as silicon nitride (for example, Si3N4) as the material for the electrical insulators 137 and 145, since the mechanical strength is not large.

Next, using FIGS. 2 and 3, the magnetic bearing rotor 1
A method of joining 14 and electrical insulator 137 will be explained. A case will be described in which ceramic, wood, and preferably silicon nitride (eg, St, N4) is used as the electrical insulator 137.

That is, as described above, the magnetic bearing rotor 114 is composed of the laminated magnetic plate 116, the cylinder 130, the bearing cylinder 114-1, and the mechanical elastic body 114-2. Mechanical elastic body 114-
It is fixed to the outer periphery of the electrical insulator 137 via 2f.

The mechanical elastic body is made of pure iron, for example, and has a shape as shown in FIG. That is, it is made cylindrical and has a plurality of, preferably eight, spaces at its ends.
;t-* is provided. Furthermore, an inwardly convex portion 114-2-0 is provided at the end thereof, and is in contact with the outer diameter of the electrical insulator 131. Mechanical elastic body 114
The outer diameter of the central part of -2 is gently tapered, and in the opposite direction is Teno J? It is mechanically and tightly joined to the inner diameter of the bearing cylinder 114-1, which is marked with -. During this time, it is firmly fixed, for example, by brazing. At both ends of such a mechanical elastic body 114-2, a tenor arm portion 114-2-b is provided.

114-2-c is formed, and the electrical insulator 13
Cheeks 137-c, 137-d on the outer periphery of 7
are formed, and these tapered portions are in close mechanical contact.

Further, the central portion of the mechanical elastic body 114-2 has a gap between it and the electrical insulator 137 that is equal to or larger than the difference in thermal expansion between the two. Moreover, the mechanical elastic body 114-2 is pickpocketed,
) 114-2-On the outside of the part having the gourd, the electrical insulator 137 is disposed between the bearing cylinder 114-1 and the bearing cylinder 114-1.
The gap is equal to or larger than the difference in thermal expansion between the two.

Further, at least one of the above-mentioned Q/'P parts 137-d and 137-c is determined at an angle that can absorb the difference in thermal expansion in the radial direction and the axial direction, depending on the inner diameter and length of the bearing rotor 114. do. Furthermore, the length, number, and wall thickness of the slits 114-2-& are determined so that no mechanical pulling force is generated in this portion.

At the time of assembly, the parent air bearing rotor 114 is assembled in advance and inserted into the electrical insulator 137 from the outside (in the direction of the smaller diameter) under high temperature and pressure. At this time, another chi/4 part 114 is placed inside the mechanical elastic body 114-2.
-2-CI is provided, and the protrusion 1 of the electrical insulator 137
Since the tapered portion 137-f is formed on the outside of the portion 37-., excessive resistance is not generated during insertion.

When the insertion is completed, the mechanical elastic body 114-2
114-2-& is subjected to a stress within the elastic limit and is mechanically firmly fixed between the electrical insulators 137.

Now, during operation, when the electric insulator 137 and the magnetic bearing rotor 114 become high temperature due to the inflow of heat from the target 4, the inside of the electric insulator 137 and the magnetic bearing rotor 114, for example, are made of ceramic or resin. lE
More than the stunning 137.

The outer bearing rotor 114 made of iron, for example, has a larger thermal expansion, but there are slits 114-2-* at both ends of the mechanical elastic body 114-2, and these parts act as so-called firmness, so the thermal expansion is moderate. This difference in thermal expansion can be absorbed. Since they are joined at the tapered part, the difference in thermal expansion in the axial direction can be absorbed by elongation within the elastic limit in the radial direction. It can be bonded with high mechanical strength. Also, since it has a sufficiently strong spring constant, the resonant frequency of this part is also l.
It has also been demonstrated that rotations of 30.00 Orpm can be increased to kHz or higher without any adverse effects. Furthermore, the rotational balance did not change significantly even when the temperature changed.

By adopting such a structure, the difference in thermal expansion was
, 1m, and the stress reaches 80kg/■2, so we created a rotor that can withstand practical use even at temperatures above 500℃, where it was thought that the external metal would yield and bonding would be impossible. I was able to do that. This made it possible to realize a large-capacity magnetically levitated X-ray tube device, which had previously been considered impossible.

Note that the other bearing rotor 115 can also be made in the same manner.

[Modified example of the invention]

In the above embodiment, a non-contact current path is used to maintain the rotors 114 and 115 at substantially ground potential, but it is also possible to have a structure in which one or both of them are brought into mechanical contact. Of course, the non-contact conductive parts 143 and 144 for supplying voltage from outside the target 4Vc tube may be changed to a conductive mechanism using mechanical contact.

Furthermore, although the rotor 114 (or 115) and the insulator 137 (or 145) are bonded over the entire surface, it goes without saying that the bonding surface may be limited to only a portion.

Further, although the target 4 and the electrical insulators 137 and 145 are connected through metal plates 138, they may be directly connected.

Furthermore, in the above embodiment, the turret and the treader 4 are supported on both sides, but the magnetic bearing stator 11 is moved to the 110 side.
Of course, a so-called one-sided holding structure may also be used.

Alternatively, a conventional mechanical bearing may be used for the bearing portion.

Moreover, the bearing cylinder 114-1 and the mechanical elastic body 11
Of course, the structure 4-2 may be an integral structure.

Further, the contact portion between the electrical insulator 137 and the mechanical elastic body 114-2 is not limited to both ends, but may also be brought into contact at the center.

Further, the mechanical elastic body 114-2 may have a multi-segmented structure.

Next, the above-mentioned bearing rotor 114 and the above-mentioned metal insulator 137
A modified example of the method of fixing will be described with reference to FIGS. 4, 5, and 6.

First, FIG. 4 shows an example in which the outer periphery of the electrical insulator 137 is cylindrical, and a part of the inner diameter of the mechanical elastic body 114-2 is shrink-fitted or press-fitted without a tee 74-. It is convenient if either one of the contact parts with the electrical insulator 137 is fixed by brazing or the like. The inner diameter of the central portion of the mechanical elastic body 114-2 is set to be larger than the outer diameter of the electrical insulator 137 by a gear or a gear that is approximately equal to the difference in thermal expansion.

FIG. 5 shows that the inner surface of the mechanically elastic body 114-2 is cylindrical, and a part of the electrical insulator 137 has a portion with a small outer diameter corresponding to the difference in thermal expansion. is 1
! ! This is an example in which the material is held elastically with the gas insulator 137.

FIG. 6 shows the mechanical elastic body 11 (-2, 114-2
This is an example where two are used. One mechanical elastic body 114-2 has a fitting part 114-2-1, and is fitted into a recess provided on the outer periphery of the electrical insulator 137, and is also movable in the axial direction. It is designed not to.

〔Effect of the invention〕

According to this invention, the following excellent effects can be obtained.

That is, since the rotating body is strong against centrifugal stress, 30.00
It is possible to rotate at ultra-high speeds on the order of Orpm, and the peak input value of the X-ray tube can be increased by 1.7 times compared to conventional tubes. In addition, since the rotating body is completely non-contact, there is low vibration and
A low-noise X-ray tube can be provided, and since no mechanical goal bearings are used, the rotational life is extremely long.

In addition, the cathode 120°12
1 is maintained at a negative high voltage, a so-called neutral point grounded high voltage power supply can be used.

In other words, since a conventional X-ray tube power source can be used, the rotating anode type X-ray tube device of the present invention can be used in a conventional X-ray generator.

In addition, since the rotors 114 and 115 are substantially at ground potential, the magnetic gap of the magnetic bearing can be made small and strong rigidity can be obtained, making it possible to drive extremely heavy (for example, 4-Y) tardas and torsos at ultra-high speeds. (For example, 30,000
rpm), it has an ultra-large capacity (
For example, a 6 MHU) x-ray tube can be provided. Furthermore, since the rotors 114 and 115 are substantially at ground potential, noise entering the position sensor 152 can be reduced, allowing stable operation.

Further, the structure of the rotors 114 and 115 is simple, and as a result, a compact and low-cost X-ray tube can be provided.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a rotating anode type X-ray tube according to an embodiment of the present invention, FIGS. 2 and 3 are sectional views and perspective views showing an enlarged main part of FIG. 6 to 6 are cross-sectional views showing modifications of the present invention, and FIG. 7 is a cross-sectional view showing a conventional rotating anode type X-ray tube. DESCRIPTION OF SYMBOLS 1...Housing, 110,111...Stator for radial magnetic bearing, 112,113...Stator for thrust magnetic bearing, 114,115...Rotor for magnetic bearing, 120,121...Grounding diode cathode, 1
37,145... electrical insulator, 4... tarr, g,
3...Cathode. Applicant's representative Patent attorney Takehiko Suzue Figure 4 Figure 5

Claims (16)

[Claims] (1) At least one cathode, a rotatable anticathode target provided opposite to the cathode, and a bearing portion rotatably supporting the anticathode target, the anticathode target being electrically A rotating anode type, characterized in that the rotating part of the bearing part is fixed to one end of an insulator, and the rotating part of the bearing part is mounted on the outer periphery of the electrical insulator, separated from the fixed part of the anticathode target in the rotation axis direction. X-ray tube equipment. (2) The rotating anode type X-ray tube device according to claim 1, wherein the bearing portion is a magnetic bearing. (3) The electrical insulator has an outer diameter at an intermediate position in the axial direction between the place where the anticathode target is fixed and the place where the rotating part of the bearing part is attached, which is equal to the diameter of the attaching part or the rotating part. The rotating anode type X-ray tube device according to claims 1 and 2, characterized in that the diameter is larger than the diameter of the place where it is installed. (4) A rotating anode type X-ray according to claims 1 to 3, characterized in that the rotating portion of the bearing portion is attached to the outer periphery of the electrical insulator via a mechanical elastic body. tube device. (5) At least one tapered part is provided on the outer periphery of the electrical insulator, and a part of the mechanical elastic body is in contact with the tapered part. The rotating anode type X-ray tube device described. (6) Claims 4 and 5, characterized in that the mechanical elastic body is cylindrical and has a slit near at least one end thereof or a portion in contact with the electrical insulator. The rotating anode type X-ray tube device described. (7) At least a portion of the mechanical elastic body is in contact with the electrical insulator, and there is a gap between the mechanical elastic body and the electrical insulator other than the contact portion. 7. The rotating anode X-ray tube device according to item 6. (8) A bearing cylinder is fixed to the outer periphery of the mechanical elastic body, and a gap is provided between them at a portion where the mechanical elastic body generates elasticity. Rotating anode type X-ray tube device. (9) The rotating anode type X-ray tube device according to claim 8, wherein the mechanical elastic body and the bearing cylinder are integrally formed. (10) At least two tapered parts in opposite directions are provided on the outer periphery of the electrical insulator, and both ends of the mechanical elastic body are inserted between the tapered parts and pressed and fixed. A rotating anode X-ray tube device according to items 1 to 9. (11) The rotating anode according to claims 8 to 10, wherein the mechanical elastic body is fixed to the bearing cylinder and then fixed to the outer periphery of the electrical insulator by shrink fitting. Type X-ray tube device. (12) A rotary anode type X-ray tube device according to any one of claims 4 to 11, characterized in that a contact portion between the mechanical elastic body and the electrical insulator is joined by brazing or the like. (13) The rotary anode type wire tube device. (14) The rotating anode X-ray tube device according to any one of claims 1 to 13, wherein the electrical insulator is Si_3N_4. (15) Claims 1 to 14 include a conductive path penetrating through the center of the electrical insulator.
Rotating anode type X-ray tube device as described in . (16) The rotating anode X-ray tube device according to any one of claims 8 to 15, further comprising means for keeping the bearing cylinder substantially at ground potential.