WO2018020895A1 - X-ray tube apparatus and x-ray ct apparatus - Google Patents

X-ray tube apparatus and x-ray ct apparatus Download PDF

Info

Publication number
WO2018020895A1
WO2018020895A1 PCT/JP2017/022294 JP2017022294W WO2018020895A1 WO 2018020895 A1 WO2018020895 A1 WO 2018020895A1 JP 2017022294 W JP2017022294 W JP 2017022294W WO 2018020895 A1 WO2018020895 A1 WO 2018020895A1
Authority
WO
WIPO (PCT)
Prior art keywords
ray
anode
ray tube
bearing
thrust bearing
Prior art date
Application number
PCT/JP2017/022294
Other languages
French (fr)
Japanese (ja)
Inventor
良規 森戸
Original Assignee
株式会社日立製作所
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社日立製作所 filed Critical 株式会社日立製作所
Publication of WO2018020895A1 publication Critical patent/WO2018020895A1/en

Links

Images

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus for radiation diagnosis, e.g. combined with radiation therapy equipment
    • A61B6/02—Devices for diagnosis sequentially in different planes; Stereoscopic radiation diagnosis
    • A61B6/03—Computerised tomographs
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C19/00—Bearings with rolling contact, for exclusively rotary movement
    • F16C19/02—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows
    • F16C19/10—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for axial load mainly
    • F16C19/12—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for axial load mainly for supporting the end face of a shaft or other member, e.g. footstep bearings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C19/00—Bearings with rolling contact, for exclusively rotary movement
    • F16C19/02—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows
    • F16C19/14—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for both radial and axial load
    • F16C19/16—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for both radial and axial load with a single row of balls
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/30—Parts of ball or roller bearings
    • F16C33/32—Balls
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/30—Parts of ball or roller bearings
    • F16C33/58—Raceways; Race rings
    • F16C33/62—Selection of substances
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/30—Parts of ball or roller bearings
    • F16C33/66—Special parts or details in view of lubrication
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J35/00—X-ray tubes
    • H01J35/02—Details
    • H01J35/04—Electrodes ; Mutual position thereof; Constructional adaptations therefor
    • H01J35/08—Anodes; Anti cathodes
    • H01J35/10—Rotary anodes; Arrangements for rotating anodes; Cooling rotary anodes

Definitions

  • Rotating anode X-ray tube device that rotates a disk-shaped anode is used for the X-ray tube device used in the X-ray CT apparatus.
  • Rotating bearings that rotatably support the anode are usually arranged at two locations at a predetermined distance in the direction of the rotating shaft portion.
  • the rotary bearing has an inner ring provided on the rotary shaft part, an outer ring provided on the inner surface of the fixed part, and a bearing ball sandwiched between the inner ring and the outer ring. In order for the rotary bearing to rotate smoothly and stably, it is desirable that the clearance between the bearing ball, the inner ring, and the outer ring be maintained in an appropriate range.
  • Patent Document 1 discloses that the bearing ball of the rotary bearing is made of ceramic, and that an ion nitride layer is formed on the raceway surfaces of the inner ring and the outer ring, thereby improving the wear resistance of the rotary bearing. Yes. Also, it is possible to ensure conductivity by coating the bearing balls and the raceways of the inner and outer rings with a metal such as silver, copper, or lead, or by mixing steel in the ceramic bearing balls. It is disclosed.
  • Patent Document 1 when all the bearing balls are made of ceramic, conductivity cannot be ensured due to progress of peeling of the coated metal. When ceramic bearing balls and steel bearing balls are mixed, the rotation of the rotary bearing becomes unstable as the wear of the steel bearing balls progresses.
  • an object of the present invention is to provide an X-ray tube apparatus having a structure capable of reducing wear of a rotary bearing while ensuring conductivity, and to provide an X-ray CT apparatus equipped with the X-ray tube apparatus. is there.
  • the radial bearing disposed along the circumference of the rotary shaft portion is made of ceramic.
  • the thrust bearing disposed on the bottom surface of the rotating shaft portion is made of metal, and the rotating shaft portion has a conducting portion that electrically connects the anode and the thrust bearing.
  • the present invention relates to an anode that emits X-rays when irradiated with an electron beam, a rotary shaft connected to the anode, and a rotary bearing that rotatably supports the rotary shaft.
  • the rotary bearing includes a radial bearing disposed on an outer periphery of the rotary shaft portion and a thrust bearing disposed on a bottom surface of the rotary shaft portion, and the radial bearing Is an X-ray tube device, wherein the thrust bearing is made of metal, and the rotating shaft portion has a conducting portion that electrically connects the anode and the thrust bearing.
  • the present invention also includes the X-ray tube device, an X-ray detector that is disposed opposite to the X-ray tube device and detects X-rays transmitted through the subject, the X-ray tube device, and the X-ray detector.
  • a rotating disk that is mounted and rotates around the subject, an image reconstruction device that reconstructs a tomographic image of the subject based on transmitted X-ray doses from a plurality of angles detected by the X-ray detector, and the image
  • An X-ray CT apparatus comprising: an image display device that displays a tomographic image reconstructed by a reconstruction device.
  • an X-ray tube apparatus having a structure capable of reducing wear of a rotary bearing while ensuring conductivity, and to provide an X-ray CT apparatus equipped with the X-ray tube apparatus It becomes.
  • the block diagram which shows the whole structure of the X-ray CT apparatus 1 of this invention The figure which shows the whole structure of the X-ray tube apparatus 101 of this invention
  • electrical_connection part 301A of the 1st Embodiment of this invention The figure which shows the conduction
  • the conducting part is constituted by a liquid metal filled in a hollow part provided in the rotating shaft part.
  • An X-ray CT apparatus includes an X-ray source that irradiates a subject with X-rays, an X-ray detector that is disposed opposite to the X-ray source and detects X-rays transmitted through the subject, An image reconstruction for reconstructing a tomographic image of a subject based on a rotating disk mounted with the X-ray source and the X-ray detector and rotating around the subject, and a transmitted X-ray dose detected by the X-ray detector. And an image display device that displays a tomographic image reconstructed by the image reconstruction device, wherein the X-ray source is the X-ray tube device.
  • the scan gantry unit 100 includes an X-ray tube device 101, a rotating disk 102, a collimator 103, an X-ray detector 106, a data collection device 107, a bed 105, a gantry control device 108, and a bed control device 109.
  • the X-ray tube device 101 is a device that irradiates a subject placed on a bed 105 with X-rays. The configuration of the X-ray tube apparatus 101 will be described later with reference to FIG.
  • the collimator 103 is a device that limits the radiation range of X-rays emitted from the X-ray tube device 101.
  • the rotating disk 102 includes an opening 104 through which a subject placed on a bed 105 enters, an X-ray tube apparatus 101 and an X-ray detector 106, and the X-ray tube apparatus 101 and the X-ray detector 106. Is rotated around the subject.
  • the console 120 includes an input device 121, an image calculation device 122, a display device 125, a storage device 123, and a system control device 124.
  • the input device 121 is a device for inputting a subject's name, examination date and time, imaging conditions, and the like, specifically a keyboard or a pointing device.
  • the image calculation device 122 is a device that reconstructs a tomographic image by calculating the measurement data sent from the data collection device 107.
  • X-ray irradiation from the X-ray tube apparatus 101 and transmission X-ray distribution measurement by the X-ray detector 106 are repeated along with the rotation of the rotating disk 102, whereby projection data from various angles is acquired.
  • the acquired projection data from various angles is transmitted to the image calculation device 122.
  • the image calculation device 122 reconstructs a tomographic image by backprojecting the transmitted projection data from various angles.
  • the tomographic image obtained by reconstruction is displayed on the display device 125.
  • the X-ray tube 210 includes a cathode 211 that generates an electron beam, an anode 212 to which a positive potential is applied to the cathode 211, and an envelope 213 that holds the cathode 211 and the anode 212 in a vacuum atmosphere.
  • Electrons emitted from the cathode 211 are accelerated by a voltage applied between the cathode and the anode and become an electron beam 216.
  • X-rays 217 are generated from the X-ray focal point.
  • the energy of the generated X-ray is determined by the voltage applied between the cathode and the anode, so-called tube voltage.
  • the dose of X-rays generated is determined by the amount of electrons emitted from the cathode, the so-called tube current and the tube voltage.
  • the rotation axis of the anode 212 is referred to as a rotation axis 219 using the reference numeral 219.
  • the rotating body support unit 215 drives the magnetic field generated by the excitation coil 214 as a rotational driving force.
  • the X-ray focal point where the electron beam 216 collides always moves, so that the temperature of the X-ray focal point can be kept lower than the melting point of the target, and the anode 212 can be overheated and melted. Can be prevented.
  • the rotating cylindrical portion 302 has a cylindrical shape, and a fixed portion 300 and a rotating shaft portion 301 are disposed inside the rotating cylindrical portion 302.
  • the rotating cylindrical portion 302 rotates around the rotating shaft 219 using the magnetic field generated by the exciting coil 214 as a driving force.
  • the anode 212 and the rotating shaft portion 301 connected to the rotating cylindrical portion 302 rotate. That is, in the X-ray tube apparatus 101, the rotating cylindrical portion 302, the anode 212, and the rotating shaft portion 301 are rotating bodies.
  • the radial bearings 303a and 303b are arranged at two locations on the outer periphery of the rotating shaft 301 and separated by a predetermined distance in the direction of the rotating shaft 219.
  • a spacer 305 which is a cylindrical spacer, is disposed between the radial bearings 303a and 303b. Since the radial bearing 303a and the radial bearing 303b are only different in position and orientation and have the same structure, only the structure of the radial bearing 303b will be described below with reference to FIG.
  • FIG. 3 (b) is an enlarged view of a dotted line square portion of the radial bearing 303b in FIG. 3 (a).
  • the radial bearing 303b has an inner ring 303b-1, a bearing ball 303b-2, and an outer ring 303b-3.
  • the inner ring 303b-1 is an arc-shaped groove formed on the outer periphery of the rotating shaft 301.
  • the outer ring 303b-3 is an annular member having an arc-shaped groove on the inner side, and is in contact with the inner peripheral surface of the fixed portion 300.
  • the outer ring 303b-3 is concentric with the rotating shaft 301 and is disposed so that the grooves of the inner ring 303b-1 and the outer ring 303b-3 face each other.
  • a plurality of bearing balls 303b-2 are arranged along the outer periphery of the rotating shaft 301 between the inner ring 303b-1 and the outer ring 303b-3. As the rotation shaft 301, that is, the inner ring 303b-1, rotates, the plurality of bearing balls 303b-2 rotate, so that the rotation shaft 301 is rotatably supported by the fixed portion 300.
  • the rotation-side raceway surface 304-1 is an arc-shaped groove formed on the bottom surface of a metal disk disposed on the bottom surface of the rotation shaft portion 301.
  • the fixed-side raceway surface 304-3 is an arc-shaped groove formed on the bottom surface of the fixed portion 300, and is formed to face the rotation-side raceway surface 304-1.
  • a plurality of bearing balls 304-2 are disposed between the rotation-side raceway surface 304-1 and the fixed-side raceway surface 304-3.
  • a plurality of bearing balls 304-2 rotate with the rotation of the rotating shaft 301, that is, the rotation-side raceway surface 304-1 so that the rotating shaft 301 is rotatably supported with respect to the fixed portion 300. .
  • a soft metal lubricant is applied between the bearing balls 304-2, the rotation-side raceway surface 304-1 and the fixed-side raceway surface 304-3 in order to reduce friction caused by rotation.
  • FIG. 4 is a cross-sectional view of the rotating body support 215.
  • the heat flow path is indicated by a solid line arrow
  • the current path is indicated by a dotted line arrow
  • the thickness of the solid line arrow indicates the amount of heat flowing
  • the ceramic part is indicated by a shade.
  • a preload spring 400 may be provided between the thrust bearing 304 and the fixed portion 300 to keep a gap in the rotary bearing appropriately.
  • the arc-shaped groove formed on the bottom surface of the metal disk disposed between the preload spring 400 and the bearing ball 304-2 becomes the fixed-side raceway surface 304-3. .
  • the ceramic rotating shaft portion 302 Most of the heat generated in the anode 212 is shielded by the ceramic rotating shaft portion 302 and flows from the surface of the anode 212 and the rotating cylindrical portion 302 to the envelope 213 by radiation. Further, the remaining heat is conducted to the fixed portion 300 via the radial bearings 303a and 303b. Further, a small amount of remaining heat is conducted to the fixed portion 300 via the thrust bearing 304 located farther from the anode 212 than the radial bearings 303a and 303b. Accordingly, the thrust bearing 304 and the soft metal lubricant applied to the thrust bearing 304 can reduce the influence of heat.
  • the electrons irradiated on the anode 212 cannot flow to the outside of the X-ray tube apparatus 101 via the radial bearings 303a and 303b, but are thrust bearings 304, preload springs 400, and fixed parts 300 via the conduction part 301A. It is possible to flow to the outside of the X-ray tube device 101 through the path. That is, a current flows through a path of the fixed portion 300, the preload spring 400, the thrust bearing 304, the conducting portion 301A, and the anode 212.
  • the conducting portion 301A shown in FIG. 5 is a metal elastic body, for example, a metal spring having a spiral shape.
  • the conductive portion 301A can absorb the difference in thermal expansion coefficient between the conductive portion 301A made of metal and the rotating shaft portion 301 made of ceramic.
  • the conducting portion 301A is connected to the anode 212 that is at a high temperature, a heat-resistant material such as tungsten, tantalum, or a nickel-based alloy is desirable. Furthermore, in order to reduce the amount of heat conducted through the conducting portion 301A, it is preferable to increase the number of turns of the spring as much as possible and lengthen the heat flow path to the thrust bearing 304.
  • FIG. 5 shows an example of a metal spring having a spiral shape
  • the conducting portion 301A may be a metal elastic body and may be a leaf spring.
  • the radial bearings 303a and 303b are made of ceramic
  • the thrust bearing 304 is made of metal
  • a part of the rotary shaft 301 which is mostly made of ceramic, is made of a metal that is elongated in the direction of the rotary shaft 219.
  • the radial bearings 303a and 303b which are subjected to a large load, are made of ceramics having excellent wear resistance due to the fact that the central axis of the rotary disk 102 of the X-ray CT apparatus 1 and the rotary shaft 219 are parallel. The life of the tube apparatus 101 can be extended. Further, by making the radial bearings 303a and 303b made of ceramic having excellent heat resistance, the radial bearings 303a and 303b can be disposed in the vicinity of the anode 212.
  • the radial bearing 303a, 303b, 303b can be driven stably.
  • the conducting portion 301A is a metal elastic body, for example, a metal spring having a spiral shape.
  • the conducting part 301A is made of liquid metal.
  • a conducting portion 301A is configured by providing a cylindrical hollow portion along the rotating shaft 219 at the center of the rotating shaft portion 301 and enclosing a liquid metal in the hollow portion.
  • the liquid metal used in the present embodiment desirably has a small volume change due to phase transition, and for example, a gallium / indium / tin alloy is used.
  • the conductivity between the anode 212 and the thrust bearing 304 is ensured by the conducting portion 301A made of a liquid metal.
  • both the ceramic rotating shaft 301 and the conducting part 301A made of a gallium / indium / tin alloy have a small volume change, so the generated thermal stress Is slight.
  • the radial bearings 303a and 303b are made of ceramic, wear of the rotary bearing can be reduced.
  • FIG. 9 A third embodiment will be described while comparing FIG. 9 with FIG.
  • a part of the ceramic rotating shaft 301 is constituted by a conducting portion 301A made of metal.
  • a part of the ceramic rotating shaft 301 is constituted by the ceramic heat insulating member 900 while keeping the conducting portion 301A as it is.
  • a ceramic heat insulating member 900 is provided between the anode 212 and the rotary shaft portion 301 or between the rotary shaft portion 301 and the saddle thrust bearing 304, so that the rotary bearing, particularly the thrust bearing. Heat inflow to 304 can be significantly reduced.

Abstract

This X-ray tube apparatus (101) is provided with: a positive electrode (212) which radiates an X-ray when irradiated with an electron beam; a rotation axis part (301) which is connected to the positive electrode (212); and a rotation bearing which rotatably supports the rotation axis part (301). The rotation bearing comprises: a radial bearing (303) which is arranged on the outer circumference of the rotation axis part and a thrust bearing (304) which is arranged on the bottom surface of the rotation axis part. The radial bearing (303a, 303b) is formed from a ceramic, while the thrust bearing (304) is formed from a metal. The rotation axis part (301) is able to reduce wear of the rotation bearing, while ensuring electrical conductivity by having a conduction part (301A) that electrically connects the positive electrode (212) and the thrust bearing (304) with each other. An X-ray CT apparatus is equipped with this X-ray tube apparatus (101).

Description

Ｘ線管装置及びＸ線ＣＴ装置X-ray tube apparatus and X-ray CT apparatus
　本発明はX線管装置及びX線CT(Computed Tomography)装置に係わり、特に回転陽極型X線管装置の回転軸受に関する。 The present invention relates to an X-ray tube apparatus and an X-ray CT (Computed Tomography) apparatus, and more particularly to a rotary bearing of a rotary anode X-ray tube apparatus.
　X線CT装置とは、被検体にX線を照射するX線管装置と、被検体を透過したX線量を投影データとして検出するX線検出器と、を被検体の周囲で回転させることにより得られる複数角度からの投影データを用いて被検体の断層画像を再構成し、再構成された断層画像を表示するものである。X線CT装置で表示される画像は、被検体の中の臓器の形状を描写するものであり、画像診断に使用される。 An X-ray CT device is an X-ray tube device that irradiates a subject with X-rays, and an X-ray detector that detects X-ray dose transmitted through the subject as projection data by rotating the subject around the subject. The tomographic image of the subject is reconstructed using the obtained projection data from a plurality of angles, and the reconstructed tomographic image is displayed. The image displayed by the X-ray CT apparatus describes the shape of an organ in the subject and is used for diagnostic imaging.
　X線CT装置に用いられるX線管装置には、円盤形状の陽極を回転させる回転陽極型X線管装置が使用される。陽極を回転可能に支持する回転軸受は、回転軸部の回転軸方向に所定の距離を隔てて通常二か所に配置される。回転軸受は、回転軸部上の設けられる内輪と、固定部の内面に設けられる外輪と、内輪と外輪に挟まれる軸受ボールを有している。回転軸受が円滑かつ安定に回転するためには、軸受ボール及び内輪、外輪の隙間が適正な範囲に保たれることが望ましい。 Rotating anode X-ray tube device that rotates a disk-shaped anode is used for the X-ray tube device used in the X-ray CT apparatus. Rotating bearings that rotatably support the anode are usually arranged at two locations at a predetermined distance in the direction of the rotating shaft portion. The rotary bearing has an inner ring provided on the rotary shaft part, an outer ring provided on the inner surface of the fixed part, and a bearing ball sandwiched between the inner ring and the outer ring. In order for the rotary bearing to rotate smoothly and stably, it is desirable that the clearance between the bearing ball, the inner ring, and the outer ring be maintained in an appropriate range.
　X線管装置では、X線発生時に陽極で大きな熱負荷が与えられ、その熱が回転軸受に伝導する。その結果、回転軸受に大きな熱応力が発生し、回転軸受を摩耗させ、摩耗が進むと回転軸受の回転が不安定になり、やがて寿命を迎える。 In the X-ray tube device, a large heat load is applied to the anode when X-rays are generated, and the heat is conducted to the rotary bearing. As a result, a large thermal stress is generated in the rotary bearing, and the rotary bearing is worn. When the wear progresses, the rotation of the rotary bearing becomes unstable and eventually reaches the end of its life.
　そこで、特許文献1には、回転軸受の軸受ボールをセラミック製にするとともに、内輪と外輪の軌道面にイオン窒化層を形成することで、回転軸受の耐摩耗性を向上させることが開示されている。また、軸受ボール並びに内輪と外輪の軌道面に銀や銅、鉛等の金属をコーティングしたり、セラミック製の軸受ボールの中に鋼製を混在させたりすることにより、導電性を確保することが開示されている。 Therefore, Patent Document 1 discloses that the bearing ball of the rotary bearing is made of ceramic, and that an ion nitride layer is formed on the raceway surfaces of the inner ring and the outer ring, thereby improving the wear resistance of the rotary bearing. Yes. Also, it is possible to ensure conductivity by coating the bearing balls and the raceways of the inner and outer rings with a metal such as silver, copper, or lead, or by mixing steel in the ceramic bearing balls. It is disclosed.
特開2008-243694号公報JP 2008-243694
　しかしながら、特許文献1では、全ての軸受ボールをセラミック製とした場合には、コーティングされた金属の剥がれが進むことにより導電性が確保できなくなる。またセラミック製の軸受ボールと鋼製の軸受ボールを混在させた場合には、鋼製の軸受ボールの摩耗が進むにつれて回転軸受の回転が不安定になる。 However, in Patent Document 1, when all the bearing balls are made of ceramic, conductivity cannot be ensured due to progress of peeling of the coated metal. When ceramic bearing balls and steel bearing balls are mixed, the rotation of the rotary bearing becomes unstable as the wear of the steel bearing balls progresses.
　そこで本発明の目的は、導電性を確保しながら、回転軸受の摩耗を低減できる構造のX線管装置を提供すること、及びそのX線管装置を搭載するX線CT装置を提供することである。 Therefore, an object of the present invention is to provide an X-ray tube apparatus having a structure capable of reducing wear of a rotary bearing while ensuring conductivity, and to provide an X-ray CT apparatus equipped with the X-ray tube apparatus. is there.
　上記目的を達成するために本発明は、陽極に接続される回転軸部を回転可能に支持する回転軸受のうち、前記回転軸部の円周に沿って配置されるラジアル軸受がセラミック製であり、前記回転軸部の底面に配置されるスラスト軸受が金属製であって、前記回転軸部は前記陽極と前記スラスト軸受とを電気的に導通させる導通部を有することを特徴とする。 In order to achieve the above object, according to the present invention, among the rotary bearings that rotatably support the rotary shaft portion connected to the anode, the radial bearing disposed along the circumference of the rotary shaft portion is made of ceramic. The thrust bearing disposed on the bottom surface of the rotating shaft portion is made of metal, and the rotating shaft portion has a conducting portion that electrically connects the anode and the thrust bearing.
　より具体的には、本発明は、電子線が照射されることでX線を放射する陽極と、前記陽極に接続される回転軸部と、前記回転軸部を回転可能に支持する回転軸受と、を備えるX線管装置であって、前記回転軸受は前記回転軸部の外周に配置されるラジアル軸受と前記回転軸部の底面に配置されるスラスト軸受とを有しており、前記ラジアル軸受はセラミック製であり、前記スラスト軸受は金属製であって、前記回転軸部は前記陽極と前記スラスト軸受とを電気的に導通させる導通部を有することを特徴とするX線管装置である。 More specifically, the present invention relates to an anode that emits X-rays when irradiated with an electron beam, a rotary shaft connected to the anode, and a rotary bearing that rotatably supports the rotary shaft. The rotary bearing includes a radial bearing disposed on an outer periphery of the rotary shaft portion and a thrust bearing disposed on a bottom surface of the rotary shaft portion, and the radial bearing Is an X-ray tube device, wherein the thrust bearing is made of metal, and the rotating shaft portion has a conducting portion that electrically connects the anode and the thrust bearing.
　また、本発明は、前記X線管装置と、前記X線管装置に対向配置され被検体を透過したX線を検出するX線検出器と、前記X線管装置と前記X線検出器を搭載し前記被検体の周囲を回転する回転円盤と、前記X線検出器により検出された複数角度からの透過X線量に基づき前記被検体の断層画像を再構成する画像再構成装置と、前記画像再構成装置により再構成された断層画像を表示する画像表示装置と、を備えることを特徴とするX線CT装置である。 The present invention also includes the X-ray tube device, an X-ray detector that is disposed opposite to the X-ray tube device and detects X-rays transmitted through the subject, the X-ray tube device, and the X-ray detector. A rotating disk that is mounted and rotates around the subject, an image reconstruction device that reconstructs a tomographic image of the subject based on transmitted X-ray doses from a plurality of angles detected by the X-ray detector, and the image An X-ray CT apparatus comprising: an image display device that displays a tomographic image reconstructed by a reconstruction device.
　本発明によれば、導電性を確保しながら、回転軸受の摩耗を低減できる構造のX線管装置を提供すること、及びそのX線管装置を搭載するX線CT装置を提供することが可能となる。 According to the present invention, it is possible to provide an X-ray tube apparatus having a structure capable of reducing wear of a rotary bearing while ensuring conductivity, and to provide an X-ray CT apparatus equipped with the X-ray tube apparatus It becomes.
本発明のX線CT装置1の全体構成を示すブロック図The block diagram which shows the whole structure of the X-ray CT apparatus 1 of this invention 本発明のX線管装置101の全体構成を示す図The figure which shows the whole structure of the X-ray tube apparatus 101 of this invention 本発明のX線管装置101の陽極212周辺の構造を示す図The figure which shows the structure around the anode 212 of the X-ray tube apparatus 101 of this invention 熱流路と電流経路とを説明する図Diagram explaining heat flow path and current path 本発明の第1の実施形態の導通部301Aを示す図The figure which shows the conduction | electrical_connection part 301A of the 1st Embodiment of this invention 本発明の第2の実施形態の導通部301Aを示す図The figure which shows the conduction | electrical_connection part 301A of the 2nd Embodiment of this invention. 本発明の第2の実施形態の導通部301Aの変形例を示す図The figure which shows the modification of the conduction | electrical_connection part 301A of the 2nd Embodiment of this invention. 本発明の第2の実施形態の変形例での液体金属の様子を示す図The figure which shows the mode of the liquid metal in the modification of the 2nd Embodiment of this invention 本発明の第3の実施形態を示す図The figure which shows the 3rd Embodiment of this invention
　本発明に係るＸ線管装置は、電子線が照射されることでＸ線を放射する陽極と、前記陽極に接続される回転軸部と、前記回転軸部を回転可能に支持する回転軸受と、を備え、前記回転軸受は前記回転軸部の外周に配置されるラジアル軸受と前記回転軸部の底面に配置されるスラスト軸受とを有しており、前記ラジアル軸受はセラミック製であり、前記スラスト軸受は金属製であって、前記回転軸部は前記陽極と前記スラスト軸受とを電気的に導通させる導通部を有することを特徴とする。 An X-ray tube apparatus according to the present invention includes an anode that emits X-rays when irradiated with an electron beam, a rotary shaft portion connected to the anode, and a rotary bearing that rotatably supports the rotary shaft portion. The rotary bearing includes a radial bearing disposed on an outer periphery of the rotating shaft portion and a thrust bearing disposed on a bottom surface of the rotating shaft portion, and the radial bearing is made of ceramic, The thrust bearing is made of metal, and the rotating shaft portion has a conducting portion that electrically connects the anode and the thrust bearing.
　また、前記導通部は、弾性体で構成されることを特徴とする。また、前記弾性体は金属バネであることを特徴とする。 Further, the conducting part is formed of an elastic body. The elastic body is a metal spring.
　また、前記導通部は、前記回転軸部の中に設けられた中空部に充てんされた液体金属によって構成されることを特徴とする。 Further, the conducting part is constituted by a liquid metal filled in a hollow part provided in the rotating shaft part.
　また、前記液体金属の充てん時の体積は、前記中空部の容積よりも小さいことを特徴とする。 Further, the volume when the liquid metal is filled is smaller than the volume of the hollow portion.
　また、前記中空部は、前記陽極または前記スラスト軸受に接触する部分の外径がそれ以外の外径よりも大きいことを特徴とする。 Further, the hollow portion is characterized in that an outer diameter of a portion contacting the anode or the thrust bearing is larger than other outer diameters.
　また、前記回転軸部は、前記陽極または前記スラスト軸受に接触する部分の熱伝導率が、それ以外の熱伝導率よりも小さいことを特徴とする。 Further, the rotary shaft portion is characterized in that the thermal conductivity of the portion in contact with the anode or the thrust bearing is smaller than the other thermal conductivity.
　また、前記陽極または前記スラスト軸受に接触する部分はジルコニアであり、前記陽極または前記スラスト軸受に接触する部分以外は窒化ケイ素または炭化ケイ素であることを特徴とする。 Further, the portion that contacts the anode or the thrust bearing is zirconia, and the portion other than the portion that contacts the anode or the thrust bearing is silicon nitride or silicon carbide.
　また、本発明に係るＸ線ＣＴ装置は、被検体にＸ線を照射するＸ線源と、前記Ｘ線源に対向配置され前記被検体を透過したＸ線を検出するＸ線検出器と、前記Ｘ線源と前記Ｘ線検出器を搭載し前記被検体の周囲を回転する回転円盤と、前記Ｘ線検出器により検出された透過Ｘ線量に基づき被検体の断層画像を再構成する画像再構成装置と、前記画像再構成装置により再構成された断層画像を表示する画像表示装置と、を備え、前記Ｘ線源が前記Ｘ線管装置であることを特徴とする。 An X-ray CT apparatus according to the present invention includes an X-ray source that irradiates a subject with X-rays, an X-ray detector that is disposed opposite to the X-ray source and detects X-rays transmitted through the subject, An image reconstruction for reconstructing a tomographic image of a subject based on a rotating disk mounted with the X-ray source and the X-ray detector and rotating around the subject, and a transmitted X-ray dose detected by the X-ray detector. And an image display device that displays a tomographic image reconstructed by the image reconstruction device, wherein the X-ray source is the X-ray tube device.
　以下、添付図面に従って本発明に係るX線CT装置及びX線CT装置に搭載されるX線管装置の好ましい実施形態について説明する。なお、以下の説明及び添付図面において、同一の機能構成を有する構成要素については、同一の符号を付することにより重複説明を省略することにする。 Hereinafter, preferred embodiments of an X-ray CT apparatus and an X-ray tube apparatus mounted on the X-ray CT apparatus according to the present invention will be described with reference to the accompanying drawings. In the following description and the accompanying drawings, the same reference numerals are given to the constituent elements having the same functional configuration, and redundant description will be omitted.
　(第1の実施形態)
　図1を用いて本発明を適用したX線CT装置1の全体構成を説明する。X線CT装置1はスキャンガントリ部100と操作卓120とを備える。 (First embodiment)
The overall configuration of the X-ray CT apparatus 1 to which the present invention is applied will be described with reference to FIG. The X-ray CT apparatus 1 includes a scan gantry unit 100 and a console 120.
　スキャンガントリ部100は、X線管装置101と、回転円盤102と、コリメータ103と、X線検出器106と、データ収集装置107と、寝台105と、ガントリ制御装置108と、寝台制御装置109と、X線制御装置110と、を備えている。X線管装置101は寝台105上に載置された被検体にX線を照射する装置である。X線管装置101の構成については図2を用いて後述する。コリメータ103はX線管装置101から照射されるX線の放射範囲を制限する装置である。 The scan gantry unit 100 includes an X-ray tube device 101, a rotating disk 102, a collimator 103, an X-ray detector 106, a data collection device 107, a bed 105, a gantry control device 108, and a bed control device 109. An X-ray control device 110. The X-ray tube device 101 is a device that irradiates a subject placed on a bed 105 with X-rays. The configuration of the X-ray tube apparatus 101 will be described later with reference to FIG. The collimator 103 is a device that limits the radiation range of X-rays emitted from the X-ray tube device 101.
　回転円盤102は、寝台105上に載置された被検体が入る開口部104を備えるとともに、X線管装置101とX線検出器106を搭載し、X線管装置101とX線検出器106を被検体の周囲で回転させるものである。 The rotating disk 102 includes an opening 104 through which a subject placed on a bed 105 enters, an X-ray tube apparatus 101 and an X-ray detector 106, and the X-ray tube apparatus 101 and the X-ray detector 106. Is rotated around the subject.
　X線検出器106は、X線管装置101と対向配置され、被検体を透過したX線を検出することにより透過X線の空間的な分布を計測する装置であり、多数のX線検出素子を回転円盤102の回転方向に配列したもの、若しくは回転円盤102の回転方向と回転軸方向との2次元に配列したものである。データ収集装置107は、X線検出器106で検出されたX線量をデジタルデータとして収集する装置である。ガントリ制御装置108は回転円盤102の回転を制御する装置である。寝台制御装置109は、寝台105の上下前後左右動を制御する装置である。X線制御装置110はX線管装置101に入力される電力を制御する装置である。 The X-ray detector 106 is a device that is arranged to face the X-ray tube device 101 and measures the spatial distribution of transmitted X-rays by detecting X-rays that have passed through the subject. Are arranged in the rotating direction of the rotating disk 102, or two-dimensionally arranged in the rotating direction of the rotating disk 102 and the rotating shaft direction. The data collection device 107 is a device that collects the X-ray dose detected by the X-ray detector 106 as digital data. The gantry control device 108 is a device that controls the rotation of the rotary disk 102. The bed control device 109 is a device that controls the vertical and horizontal movements of the bed 105. The X-ray control device 110 is a device that controls electric power input to the X-ray tube device 101.
　操作卓120は、入力装置121と、画像演算装置122と、表示装置125と、記憶装置123と、システム制御装置124とを備えている。入力装置121は、被検体氏名、検査日時、撮影条件などを入力するための装置であり、具体的にはキーボードやポインティングデバイスである。画像演算装置122は、データ収集装置107から送出される計測データを演算処理して断層画像を再構成する装置である。 The console 120 includes an input device 121, an image calculation device 122, a display device 125, a storage device 123, and a system control device 124. The input device 121 is a device for inputting a subject's name, examination date and time, imaging conditions, and the like, specifically a keyboard or a pointing device. The image calculation device 122 is a device that reconstructs a tomographic image by calculating the measurement data sent from the data collection device 107.
　表示装置125は、画像演算装置122で再構成された断層画像を表示する装置であり、具体的にはCRT(Cathode-Ray Tube)や液晶ディスプレイ等である。記憶装置123は、データ収集装置107で収集したデータ及び画像演算装置122で再構成された断層画像の画像データを記憶する装置であり、具体的にはHDD(Hard Disk Drive)等である。 The display device 125 is a device that displays a tomographic image reconstructed by the image calculation device 122, and specifically, a CRT (Cathode-Ray Tube), a liquid crystal display, or the like. The storage device 123 is a device that stores data collected by the data collection device 107 and image data of a tomographic image reconstructed by the image calculation device 122, and is specifically an HDD (Hard Disk Disk Drive) or the like.
　システム制御装置124は、これらの装置及びガントリ制御装置108と寝台制御装置109とX線制御装置110を制御する装置である。 The system control device 124 is a device that controls these devices, the gantry control device 108, the bed control device 109, and the X-ray control device 110.
　入力装置121から入力された撮影条件、特にX線管電圧やX線管電流などに基づきX線制御装置110がX線管装置101に入力される電力を制御することにより、X線管装置101は撮影条件に応じたX線を被検体に照射する。X線検出器106は、X線管装置101から照射され被検体を透過したX線を多数のX線検出素子で検出し、透過X線の分布を計測する。回転円盤102はガントリ制御装置108により制御され、入力装置121から入力された撮影条件、特に回転速度などに基づいて回転する。寝台105は寝台制御装置109によって制御され、入力装置121から入力された撮影条件、特にらせんピッチなどに基づいて動作する。 The X-ray tube device 101 is controlled by the X-ray controller 110 controlling the power input to the X-ray tube device 101 based on the imaging conditions input from the input device 121, in particular, the X-ray tube voltage and the X-ray tube current. Irradiates the subject with X-rays according to imaging conditions. The X-ray detector 106 detects X-rays irradiated from the X-ray tube apparatus 101 and transmitted through the subject with a large number of X-ray detection elements, and measures the distribution of transmitted X-rays. The rotating disk 102 is controlled by the gantry control device 108, and rotates based on the photographing conditions input from the input device 121, particularly the rotation speed. The couch 105 is controlled by the couch controller 109 and operates based on the photographing conditions input from the input device 121, particularly the helical pitch.
　X線管装置101からのX線照射とX線検出器106による透過X線分布の計測が回転円盤102の回転とともに繰り返されることにより、様々な角度からの投影データが取得される。取得された様々な角度からの投影データは画像演算装置122に送信される。画像演算装置122は送信された様々な角度からの投影データを逆投影処理することにより断層画像を再構成する。再構成して得られた断層画像は表示装置125に表示される。 X-ray irradiation from the X-ray tube apparatus 101 and transmission X-ray distribution measurement by the X-ray detector 106 are repeated along with the rotation of the rotating disk 102, whereby projection data from various angles is acquired. The acquired projection data from various angles is transmitted to the image calculation device 122. The image calculation device 122 reconstructs a tomographic image by backprojecting the transmitted projection data from various angles. The tomographic image obtained by reconstruction is displayed on the display device 125.
　図2を用いて、X線管装置101の構成について説明する。X線管装置101は、X線を発生するX線管210と、X線管210を収納する容器220とを備える。 The configuration of the X-ray tube apparatus 101 will be described with reference to FIG. The X-ray tube apparatus 101 includes an X-ray tube 210 that generates X-rays and a container 220 that stores the X-ray tube 210.
　X線管210は、電子線を発生する陰極211と、陰極211に対し正の電位が印加される陽極212と、陰極211と陽極212を真空雰囲気中に保持する外囲器213とを備える。 The X-ray tube 210 includes a cathode 211 that generates an electron beam, an anode 212 to which a positive potential is applied to the cathode 211, and an envelope 213 that holds the cathode 211 and the anode 212 in a vacuum atmosphere.
　陰極211はフィラメントもしくは冷陰極と、集束電極とを備える。フィラメントはタングステンなどの高融点材料をコイル状に巻いたものであり、電流が流されることにより加熱され、電子を放出する。冷陰極はニッケルやモリブデンなどの金属材料を鋭利に尖らせたもので、陰極表面に電界が集中することで電界放出により電子を放出する。集束電極は、放出された電子を陽極212上のX線焦点へ向けて集束させるための集束電界を形成する。
フィラメントもしくは冷陰極と、集束電極とは同電位である。 The cathode 211 includes a filament or a cold cathode and a focusing electrode. The filament is formed by winding a high melting point material such as tungsten in a coil shape, and is heated by an electric current to emit electrons. A cold cathode is a sharpened metal material such as nickel or molybdenum, and emits electrons by field emission when an electric field is concentrated on the cathode surface. The focusing electrode forms a focusing electric field for focusing the emitted electrons toward the X-ray focal point on the anode 212.
The filament or cold cathode and the focusing electrode are at the same potential.
　陽極212はターゲットと陽極母材とを備える。ターゲットはタングステンなどの高融点で原子番号の大きい材質で構成される。ターゲット上のX線焦点に陰極211から放出された電子が衝突することにより、X線焦点からX線217が放射される。陽極母材は、銅などの熱伝導率の高い材質からなり、ターゲットを保持する。ターゲットと陽極母材とは同電位である。 The anode 212 includes a target and an anode base material. The target is made of a material having a high melting point and a large atomic number, such as tungsten. X-rays 217 are emitted from the X-ray focal point when electrons emitted from the cathode 211 collide with the X-ray focal point on the target. The anode base material is made of a material having high thermal conductivity such as copper, and holds the target. The target and the anode base material are at the same potential.
　外囲器213は陰極211と陽極212の間を電気的に絶縁するために、陰極211と陽極212を真空雰囲気中に保持する。外囲器213にはX線217をX線管210外へ放射するための放射窓218が備えられる。放射窓218は、X線透過率が高いベリリウムなどの原子番号の小さい材質で構成される。放射窓218は後述する容器220にも備えられる。外囲器213の電位は接地電位である。 The envelope 213 maintains the cathode 211 and the anode 212 in a vacuum atmosphere in order to electrically insulate the cathode 211 and the anode 212 from each other. The envelope 213 is provided with a radiation window 218 for emitting X-rays 217 to the outside of the X-ray tube 210. The radiation window 218 is made of a material having a small atomic number such as beryllium having a high X-ray transmittance. The radiation window 218 is also provided in the container 220 described later. The potential of the envelope 213 is a ground potential.
　陰極211から放出された電子は、陰極と陽極との間に印加される電圧により加速され電子線216となる。電子線216が集束電界により集束されてターゲット上のX線焦点に衝突すると、X線焦点からX線217が発生する。発生するX線のエネルギーは、陰極と陽極との間に印加される電圧、いわゆる管電圧によって決まる。発生するX線の線量は、陰極から放出される電子の量いわゆる管電流と、管電圧によって決まる。 Electrons emitted from the cathode 211 are accelerated by a voltage applied between the cathode and the anode and become an electron beam 216. When the electron beam 216 is focused by the focusing electric field and collides with the X-ray focal point on the target, X-rays 217 are generated from the X-ray focal point. The energy of the generated X-ray is determined by the voltage applied between the cathode and the anode, so-called tube voltage. The dose of X-rays generated is determined by the amount of electrons emitted from the cathode, the so-called tube current and the tube voltage.
　電子線216のエネルギーの内、X線に変換される割合は1％程度に過ぎず、残りのほとんどのエネルギーは熱となる。医療用のX線CT装置1に搭載されるX線管装置101では、管電圧は百数十kV、管電流は数百mAであるので、陽極212は数十kWの熱量で加熱される。このような加熱により陽極212が過熱溶融することを防止するため、陽極212は回転体支持部215に接続されており、回転体支持部215の駆動により、図2中の1点鎖線219を回転軸として回転する。 The ratio of the electron beam 216 converted to X-rays is only about 1%, and most of the remaining energy is heat. In the X-ray tube apparatus 101 mounted on the medical X-ray CT apparatus 1, the tube voltage is hundreds of kV and the tube current is several hundred mA, so the anode 212 is heated with a heat quantity of several tens kW. In order to prevent the anode 212 from being overheated and melted by such heating, the anode 212 is connected to the rotating body support portion 215, and the one-dot chain line 219 in FIG. Rotates as an axis.
　以降の説明では、陽極212の回転軸を、符号219を用いて回転軸219と呼ぶ。回転体支持部215は、励磁コイル214が発生した磁界を回転駆動力として駆動する。陽極212を回転させることで、電子線216が衝突する部分であるX線焦点が常に移動するので、X線焦点の温度をターゲットの融点より低く保つことができ、陽極212が過熱溶融することを防止できる。 In the following description, the rotation axis of the anode 212 is referred to as a rotation axis 219 using the reference numeral 219. The rotating body support unit 215 drives the magnetic field generated by the excitation coil 214 as a rotational driving force. By rotating the anode 212, the X-ray focal point where the electron beam 216 collides always moves, so that the temperature of the X-ray focal point can be kept lower than the melting point of the target, and the anode 212 can be overheated and melted. Can be prevented.
　X線管210と励磁コイル214とは、容器220の中に収納される。容器220の中には、X線管210を電気的に絶縁するとともに冷却媒体となる絶縁油が充填される。容器220内に充填された絶縁油は、X線管装置101の容器220に接続された配管を通じて冷却器に導かれ、冷却器にて熱を放散した後、配管を通じて容器220内に戻される。 The X-ray tube 210 and the excitation coil 214 are accommodated in the container 220. The container 220 is filled with insulating oil that electrically insulates the X-ray tube 210 and serves as a cooling medium. The insulating oil filled in the container 220 is guided to a cooler through a pipe connected to the container 220 of the X-ray tube apparatus 101, dissipates heat in the cooler, and then returned to the container 220 through the pipe.
　X線焦点で発生した熱により陽極212は平均温度1000℃程度となる。発生した熱の大半は陽極212の表面からの輻射により外囲器213へ放熱され、残りの熱は熱伝導により回転体支持部215を通じて外囲器213へ流れる。 The average temperature of the anode 212 is about 1000 ° C. due to the heat generated at the X-ray focal point. Most of the generated heat is radiated to the envelope 213 by radiation from the surface of the anode 212, and the remaining heat flows to the envelope 213 through the rotating body support portion 215 by heat conduction.
　図3を用いて、陽極212に接続される回転体支持部215について説明する。図3(a)は陽極212周辺の構造を示す図であり、回転軸219に沿った断面図である。なお、図面を簡略化するため、図3(a)には回転軸219より上側の半分を図示している。回転体支持部215は、陽極212が陰極211と対向する面の裏側に接続され、固定部300と、回転軸部301と、回転軸受であるラジアル軸受303a、303bとスラスト軸受304と、回転円筒部302と、間座305を備えている。図3において、金属製の部分を斜線で、セラミック製の部分を陰影で示している。 The rotating body support 215 connected to the anode 212 will be described with reference to FIG. FIG. 3 (a) is a view showing the structure around the anode 212, and is a cross-sectional view along the rotation axis 219. FIG. In order to simplify the drawing, FIG. 3A shows the upper half of the rotating shaft 219. The rotating body support portion 215 is connected to the back side of the surface where the anode 212 faces the cathode 211, the fixed portion 300, the rotating shaft portion 301, radial bearings 303a and 303b which are rotating bearings, a thrust bearing 304, and a rotating cylinder. A part 302 and a spacer 305 are provided. In FIG. 3, the metal portion is indicated by diagonal lines, and the ceramic portion is indicated by shading.
　固定部300は、円筒の一端に底面が設けられた形状と段付き円柱部を組み合わせた形状を有する金属製の部材であり、円柱部の一端が外囲器213に支持される。 The fixing portion 300 is a metal member having a shape in which a shape in which a bottom surface is provided at one end of a cylinder and a stepped column portion is combined, and one end of the column portion is supported by the envelope 213.
　回転軸部301は、段付き円柱形状を有しており、固定部300の円筒の内側に配置され、回転軸受であるラジアル軸受303a、303bとスラスト軸受304によって固定部300に対して回転可能に支持される。回転軸部301には陽極212が接続され、陽極212には回転円筒部302が接続される。回転軸部301の大部分はセラミック製であるが、回転軸部301の一部は金属製である導通部301Aで構成される。導通部301Aは回転軸219の方向に細長い形状を有する。導通部301Aについては後で詳細に説明する。 The rotating shaft portion 301 has a stepped columnar shape, and is disposed inside the cylinder of the fixed portion 300, and can be rotated with respect to the fixed portion 300 by radial bearings 303a and 303b and thrust bearings 304 which are rotary bearings. Supported. An anode 212 is connected to the rotating shaft portion 301, and a rotating cylindrical portion 302 is connected to the anode 212. Most of the rotating shaft 301 is made of ceramic, but a part of the rotating shaft 301 is composed of a conducting portion 301A made of metal. The conducting portion 301A has an elongated shape in the direction of the rotation shaft 219. The conductive portion 301A will be described in detail later.
　回転円筒部302は円筒形状を有し、回転円筒部302の内側には固定部300及び回転軸部301が配置される。回転円筒部302は、励磁コイル214が発生する磁界を駆動力として、回転軸219を中心として回転する。回転円筒部302の回転に伴い、回転円筒部302に接続される陽極212及び回転軸部301が回転する。すなわち、X線管装置101において、回転円筒部302と、陽極212、回転軸部301が回転体となる。 The rotating cylindrical portion 302 has a cylindrical shape, and a fixed portion 300 and a rotating shaft portion 301 are disposed inside the rotating cylindrical portion 302. The rotating cylindrical portion 302 rotates around the rotating shaft 219 using the magnetic field generated by the exciting coil 214 as a driving force. As the rotating cylindrical portion 302 rotates, the anode 212 and the rotating shaft portion 301 connected to the rotating cylindrical portion 302 rotate. That is, in the X-ray tube apparatus 101, the rotating cylindrical portion 302, the anode 212, and the rotating shaft portion 301 are rotating bodies.
　回転軸受であるラジアル軸受303a、303bとスラスト軸受304は、回転軸部301を固定部300に対して回転可能に支持するものであって、いわゆる転がり軸受である。以下、図3(b)、図3(c)を用いながら、ラジアル軸受303a、303b、及びスラスト軸受304の構造をそれぞれ説明する。 The radial bearings 303a and 303b and the thrust bearing 304, which are rotary bearings, are so-called rolling bearings that support the rotary shaft portion 301 so as to be rotatable with respect to the fixed portion 300. Hereinafter, the structures of the radial bearings 303a and 303b and the thrust bearing 304 will be described with reference to FIGS. 3 (b) and 3 (c).
　ラジアル軸受303a、303bは、回転軸部301の外周であって、回転軸219方向に所定の距離を隔てた二か所に配置される。ラジアル軸受303a、303bの間には、円筒形状のスペーサである間座305が配置される。ラジアル軸受303aとラジアル軸受303bとは、配置される位置と向きが異なるだけであり構造は同じであるので、以降ではラジアル軸受303bの構造についてのみ図3(b)を用いて説明する。図3(b)は図3(a)中のラジアル軸受303bの点線四角部を拡大した図である。ラジアル軸受303bは、内輪303b-1と、軸受ボール303b-2と、外輪303b-3とを有する。 The radial bearings 303a and 303b are arranged at two locations on the outer periphery of the rotating shaft 301 and separated by a predetermined distance in the direction of the rotating shaft 219. A spacer 305, which is a cylindrical spacer, is disposed between the radial bearings 303a and 303b. Since the radial bearing 303a and the radial bearing 303b are only different in position and orientation and have the same structure, only the structure of the radial bearing 303b will be described below with reference to FIG. FIG. 3 (b) is an enlarged view of a dotted line square portion of the radial bearing 303b in FIG. 3 (a). The radial bearing 303b has an inner ring 303b-1, a bearing ball 303b-2, and an outer ring 303b-3.
　内輪303b-1は回転軸部301の外周に形成された円弧形状の溝である。外輪303b-3は、内側に円弧形状の溝を有する円環形状の部材であって、固定部300の内周面に接している。
外輪303b-3は回転軸部301と同心であって、内輪303b-1と外輪303b-3の溝が対向するように配置される。内輪303b-1と外輪303b-3との間には、複数個の軸受ボール303b-2が回転軸部301の外周に沿って配置される。回転軸部301、すなわち内輪303b-1の回転にともなって、複数個の軸受ボール303b-2が回転することにより、回転軸部301が固定部300に対して回転可能に支持される。 The inner ring 303b-1 is an arc-shaped groove formed on the outer periphery of the rotating shaft 301. The outer ring 303b-3 is an annular member having an arc-shaped groove on the inner side, and is in contact with the inner peripheral surface of the fixed portion 300.
The outer ring 303b-3 is concentric with the rotating shaft 301 and is disposed so that the grooves of the inner ring 303b-1 and the outer ring 303b-3 face each other. A plurality of bearing balls 303b-2 are arranged along the outer periphery of the rotating shaft 301 between the inner ring 303b-1 and the outer ring 303b-3. As the rotation shaft 301, that is, the inner ring 303b-1, rotates, the plurality of bearing balls 303b-2 rotate, so that the rotation shaft 301 is rotatably supported by the fixed portion 300.
　内輪303b-1、軸受ボール303b-2、外輪303b-3はセラミック製であって、例えば窒化ケイ素(Si3N4)や炭化ケイ素(SiC)で構成される。つまり、ラジアル軸受303a、303bはセラミック製であって、耐熱性及び耐摩耗性について、金属製の回転軸受よりも優れた特性を有する。 The inner ring 303b-1, the bearing ball 303b-2, and the outer ring 303b-3 are made of ceramic and are made of, for example, silicon nitride (Si 3 N 4 ) or silicon carbide (SiC). That is, the radial bearings 303a and 303b are made of ceramic, and have heat resistance and wear resistance superior to those of metal rotary bearings.
　スラスト軸受304は、回転軸部301の底面に配置される。図3(a)中のスラスト軸受304の点線四角部を拡大した図である図3(c)を用いて、スラスト軸受304を説明する。スラスト軸受304は、回転側軌道面304-1と、軸受ボール304-2と、固定側軌道面304-3とを有する。 The thrust bearing 304 is disposed on the bottom surface of the rotating shaft portion 301. The thrust bearing 304 will be described with reference to FIG. 3 (c), which is an enlarged view of the dotted square portion of the thrust bearing 304 in FIG. 3 (a). The thrust bearing 304 includes a rotation side raceway surface 304-1, a bearing ball 304-2, and a fixed side raceway surface 304-3.
　回転側軌道面304-1は、回転軸部301の底面に配置された金属製の円板の底面に形成された円弧形状の溝である。固定側軌道面304-3は、固定部300の底面に形成された円弧形状の溝であり、回転側軌道面304-1に対向するように形成される。回転側軌道面304-1と固定側軌道面304-3との間には、複数個の軸受ボール304-2が配置される。回転軸部301、すなわち回転側軌道面304-1の回転にともなって、複数個の軸受ボール304-2が回転することにより、回転軸部301が固定部300に対して回転可能に支持される。なお、軸受ボール304-2と、回転側軌道面304-1及び固定側軌道面304-3の間には、回転にともなう摩擦を低減するために軟質金属の潤滑剤が塗布される。 The rotation-side raceway surface 304-1 is an arc-shaped groove formed on the bottom surface of a metal disk disposed on the bottom surface of the rotation shaft portion 301. The fixed-side raceway surface 304-3 is an arc-shaped groove formed on the bottom surface of the fixed portion 300, and is formed to face the rotation-side raceway surface 304-1. A plurality of bearing balls 304-2 are disposed between the rotation-side raceway surface 304-1 and the fixed-side raceway surface 304-3. A plurality of bearing balls 304-2 rotate with the rotation of the rotating shaft 301, that is, the rotation-side raceway surface 304-1 so that the rotating shaft 301 is rotatably supported with respect to the fixed portion 300. . Note that a soft metal lubricant is applied between the bearing balls 304-2, the rotation-side raceway surface 304-1 and the fixed-side raceway surface 304-3 in order to reduce friction caused by rotation.
　図4を用いて、回転体支持部215における熱流路と電流経路とについて説明する。図4は回転体支持部215の断面図である。図4では、熱流路は実線の矢印で、電流経路は点線の矢印で示され、実線の矢印の太さは流れる熱量の大きさを示し、セラミック製の部分を陰影で示している。なお図4に示すように、スラスト軸受304と固定部300との間に、回転軸受内の隙間を適切に保つための予圧バネ400を設けても良い。予圧バネ400を設けた場合は、予圧バネ400と軸受ボール304-2との間に配置された金属製の円板の底面に形成された円弧形状の溝が固定側軌道面304-3となる。 The heat flow path and current path in the rotating body support 215 will be described with reference to FIG. FIG. 4 is a cross-sectional view of the rotating body support 215. In FIG. 4, the heat flow path is indicated by a solid line arrow, the current path is indicated by a dotted line arrow, the thickness of the solid line arrow indicates the amount of heat flowing, and the ceramic part is indicated by a shade. As shown in FIG. 4, a preload spring 400 may be provided between the thrust bearing 304 and the fixed portion 300 to keep a gap in the rotary bearing appropriately. When the preload spring 400 is provided, the arc-shaped groove formed on the bottom surface of the metal disk disposed between the preload spring 400 and the bearing ball 304-2 becomes the fixed-side raceway surface 304-3. .
　陽極212で発生した熱のほとんどは、セラミック製の回転軸部302により遮蔽され、陽極212や回転円筒部302の表面から輻射によって外囲器に213へ流れる。また、残りの熱はラジアル軸受303a、303bを介して固定部300へ伝導する。さらに、わずかな残りの熱は、ラジアル軸受303a、303bよりも陽極212から遠い位置にあるスラスト軸受304を介して固定部300へ伝導する。よってスラスト軸受304及びスラスト軸受304に塗布される軟質金属の潤滑剤は熱の影響を低減することができる。 Most of the heat generated in the anode 212 is shielded by the ceramic rotating shaft portion 302 and flows from the surface of the anode 212 and the rotating cylindrical portion 302 to the envelope 213 by radiation. Further, the remaining heat is conducted to the fixed portion 300 via the radial bearings 303a and 303b. Further, a small amount of remaining heat is conducted to the fixed portion 300 via the thrust bearing 304 located farther from the anode 212 than the radial bearings 303a and 303b. Accordingly, the thrust bearing 304 and the soft metal lubricant applied to the thrust bearing 304 can reduce the influence of heat.
　一方、陽極212に照射された電子は、ラジアル軸受303a、303b を介してX線管装置101の外部へ流れることができないが、導通部301Aを介してスラスト軸受304、予圧バネ400、固定部300という経路でX線管装置101の外部へ流れることができる。すなわち、固定部300、予圧バネ400、スラスト軸受304、導通部301A、陽極212という経路で電流が流れる。 On the other hand, the electrons irradiated on the anode 212 cannot flow to the outside of the X-ray tube apparatus 101 via the radial bearings 303a and 303b, but are thrust bearings 304, preload springs 400, and fixed parts 300 via the conduction part 301A. It is possible to flow to the outside of the X-ray tube device 101 through the path. That is, a current flows through a path of the fixed portion 300, the preload spring 400, the thrust bearing 304, the conducting portion 301A, and the anode 212.
　次に、図5を用いて導通部301Aの具体例についてより詳細に説明する。図5に示す導通部301Aは、金属の弾性体であって、例えばらせん形状を有する金属製のバネである。導通部301Aを弾性体とすることにより、金属製である導通部301Aとセラミック製である回転軸部301との熱膨張率の差を導通部301Aが吸収することができる。 Next, a specific example of the conductive portion 301A will be described in more detail with reference to FIG. The conducting portion 301A shown in FIG. 5 is a metal elastic body, for example, a metal spring having a spiral shape. By using the conductive portion 301A as an elastic body, the conductive portion 301A can absorb the difference in thermal expansion coefficient between the conductive portion 301A made of metal and the rotating shaft portion 301 made of ceramic.
　また導通部301Aは、高温になる陽極212と接続されるので、タングステンやタンタル、ニッケルベースの合金のような耐熱性のある材質が望ましい。さらに、導通部301Aを伝導する熱量を低減するために、バネの巻き数を可能な限り多くし、スラスト軸受304までの熱流路を長くすることが好ましい。なお、図5にはらせん形状を有する金属バネの例を示したが、導通部301Aは金属の弾性体であればよく、板バネであっても良い。 In addition, since the conducting portion 301A is connected to the anode 212 that is at a high temperature, a heat-resistant material such as tungsten, tantalum, or a nickel-based alloy is desirable. Furthermore, in order to reduce the amount of heat conducted through the conducting portion 301A, it is preferable to increase the number of turns of the spring as much as possible and lengthen the heat flow path to the thrust bearing 304. Although FIG. 5 shows an example of a metal spring having a spiral shape, the conducting portion 301A may be a metal elastic body and may be a leaf spring.
　以上のように、ラジアル軸受303a、303bをセラミック製、スラスト軸受304を金属製とし、大部分がセラミック製である回転軸部301の一部を、回転軸219の方向に細長い形状の金属製の導通部301Aとすることにより、X線管装置101の外部と陽極212との導電性を確保しながら、回転軸受であるラジアル軸受303a、303b及びスラスト軸受304の摩耗を低減させることができる。 As described above, the radial bearings 303a and 303b are made of ceramic, the thrust bearing 304 is made of metal, and a part of the rotary shaft 301, which is mostly made of ceramic, is made of a metal that is elongated in the direction of the rotary shaft 219. By using the conducting portion 301A, it is possible to reduce wear of the radial bearings 303a and 303b and the thrust bearing 304, which are rotary bearings, while ensuring the conductivity between the outside of the X-ray tube apparatus 101 and the anode 212.
　特に、X線CT装置1の回転円盤102の中心軸と回転軸219とが平行であることも相まって、大きな荷重がかかるラジアル軸受303a、303bを耐摩耗性に優れたセラミック製とすることによりX線管装置101の長寿命化を図ることができる。またラジアル軸受303a、303bを耐熱性に優れたセラミック製とすることにより、陽極212の近傍にラジアル軸受303a、303bを配置することが可能となる。回転円筒部302と、陽極212、回転軸部301で構成される回転体の重心は陽極212の近傍にあるので、陽極212の近傍にラジアル軸受303a、303bを配置することにより、ラジアル軸受303a、303bを安定駆動させることができる。 In particular, the radial bearings 303a and 303b, which are subjected to a large load, are made of ceramics having excellent wear resistance due to the fact that the central axis of the rotary disk 102 of the X-ray CT apparatus 1 and the rotary shaft 219 are parallel. The life of the tube apparatus 101 can be extended. Further, by making the radial bearings 303a and 303b made of ceramic having excellent heat resistance, the radial bearings 303a and 303b can be disposed in the vicinity of the anode 212. Since the center of gravity of the rotating body constituted by the rotating cylindrical portion 302, the anode 212, and the rotating shaft portion 301 is in the vicinity of the anode 212, the radial bearing 303a, 303b, 303b can be driven stably.
　さらに、導通部301Aが弾性体であることにより、セラミック製の回転軸部301と金属製の導通部301Aとの熱膨張率の差によって生じる熱応力を導通部301Aが吸収するので、回転軸部301と導通部301Aとの界面で破断を防止することができる。 Furthermore, since the conducting portion 301A is an elastic body, the conducting portion 301A absorbs the thermal stress generated by the difference in thermal expansion coefficient between the ceramic rotating shaft portion 301 and the metal conducting portion 301A. Breakage can be prevented at the interface between 301 and the conducting portion 301A.
　(第2の実施形態)
　図6を図5と対比させながら第2の実施形態について説明する。第1の実施形態では図5に示したように、導通部301Aが金属の弾性体、例えばらせん形状を有する金属製のバネであった。これに対し、本実施形態では導通部301Aを液体金属で構成する。以下、本実施形態と第一の実施形態との差異について詳細に説明し、第一の実施形態と同様の構成については説明を省略する。 (Second embodiment)
The second embodiment will be described while comparing FIG. 6 with FIG. In the first embodiment, as shown in FIG. 5, the conducting portion 301A is a metal elastic body, for example, a metal spring having a spiral shape. On the other hand, in this embodiment, the conducting part 301A is made of liquid metal. Hereinafter, differences between the present embodiment and the first embodiment will be described in detail, and the description of the same configuration as the first embodiment will be omitted.
　図6に示すように本実施形態では、回転軸部301の中心に回転軸219に沿って円柱形状の中空部を設け、中空部の中に液体金属を封入することにより導通部301Aを構成する。本実施形態に用いられる液体金属には、相転移による体積変化が小さいことが望ましく、例えばガリウム/インジウム/スズの合金が用いられる。 As shown in FIG. 6, in the present embodiment, a conducting portion 301A is configured by providing a cylindrical hollow portion along the rotating shaft 219 at the center of the rotating shaft portion 301 and enclosing a liquid metal in the hollow portion. . The liquid metal used in the present embodiment desirably has a small volume change due to phase transition, and for example, a gallium / indium / tin alloy is used.
　このような構成とすることにより、陽極212とスラスト軸受304との間の導電性は、液体金属で構成される導通部301Aにより確保される。また回転体支持部215の温度が変化した場合であっても、セラミック製の回転軸部301もガリウム/インジウム/スズの合金で構成される導通部301Aも体積変化が小さいので、発生する熱応力はわずかである。また、第1の実施形態と同様に、ラジアル軸受303a、303bはセラミック製であるので、回転軸受の摩耗を低減できる。 By adopting such a configuration, the conductivity between the anode 212 and the thrust bearing 304 is ensured by the conducting portion 301A made of a liquid metal. In addition, even when the temperature of the rotating body support 215 changes, both the ceramic rotating shaft 301 and the conducting part 301A made of a gallium / indium / tin alloy have a small volume change, so the generated thermal stress Is slight. Further, as in the first embodiment, since the radial bearings 303a and 303b are made of ceramic, wear of the rotary bearing can be reduced.
　次に図7を用いて第2の実施形態の変形例を説明する。中空部に封入される金属の体積が相転移によって変化する場合、相転移後の金属内に空隙が発生し、陽極212とスラスト軸受304との間の導電性を確保できないときがある。より具体的には、常温では固体であるガリウムで中空部を満たした場合、X線発生時の熱によって固体から液体への相転移後に体積が約3％減少する。その結果、中空部内の内圧が下がり、導通部301Aの途中に空隙が発生することで、陽極212からスラスト軸受304までの経路で導電性が確保できないことがある。 Next, a modification of the second embodiment will be described with reference to FIG. When the volume of the metal enclosed in the hollow portion changes due to the phase transition, voids are generated in the metal after the phase transition, and the conductivity between the anode 212 and the thrust bearing 304 may not be ensured. More specifically, when the hollow portion is filled with gallium which is solid at room temperature, the volume is reduced by about 3% after the phase transition from the solid to the liquid due to heat at the time of X-ray generation. As a result, the internal pressure in the hollow portion decreases, and a gap is generated in the middle of the conducting portion 301A, so that conductivity may not be ensured in the path from the anode 212 to the thrust bearing 304.
　そこで図7では、中空部の一部の外径を他の部分の外径よりも大きくする。より具体的には、陽極212またはスラスト軸受304に接触する部分の外径をそれ以外の外径よりも大きくした大径部700を設け、大径部700の形状を円錐台にする。大径部700の形状を円錐台にすると、回転軸部302の回転によって生じる遠心力の作用で、導電性を確保することができる。 Therefore, in FIG. 7, the outer diameter of a part of the hollow part is made larger than the outer diameter of the other part. More specifically, a large-diameter portion 700 in which the outer diameter of the portion in contact with the anode 212 or the thrust bearing 304 is larger than the other outer diameter is provided, and the shape of the large-diameter portion 700 is a truncated cone. When the shape of the large-diameter portion 700 is a truncated cone, conductivity can be ensured by the action of centrifugal force generated by the rotation of the rotating shaft portion 302.
　遠心力の作用により導電性を確保できるメカニズムについて図8を用いて説明する。なお、図8では金属製の部分を斜線で、セラミック製の部分を陰影で、空隙の部分を白色で示している。図8(a)は回転軸部301が静止している時であり、図8(b)は回転軸部301が回転している時である。回転軸部301が静止している時に空隙800によって陽極212と導通部301Aとの導電性が確保されない場合であっても、回転軸部301の回転によって生じる遠心力により、重い液体金属は中空部内の外側へ、軽い空隙800は中空部内の内側へ移動する。その結果、導通部301Aと陽極212またはスラスト軸受304とが必ず接触することになり、陽極212からスラスト軸受304までの経路での導電性を確保することができる。 A mechanism that can ensure conductivity by the action of centrifugal force will be described with reference to FIG. In FIG. 8, the metal portion is indicated by diagonal lines, the ceramic portion is indicated by shading, and the void portion is indicated by white. FIG. 8 (a) is when the rotating shaft 301 is stationary, and FIG. 8 (b) is when the rotating shaft 301 is rotating. Even if the air gap 800 does not ensure the conductivity between the anode 212 and the conducting portion 301A when the rotating shaft portion 301 is stationary, the heavy liquid metal is contained in the hollow portion due to the centrifugal force generated by the rotation of the rotating shaft portion 301. To the outside, the light gap 800 moves to the inside in the hollow. As a result, the conducting portion 301A and the anode 212 or the thrust bearing 304 always come into contact with each other, and the conductivity in the path from the anode 212 to the thrust bearing 304 can be ensured.
　以上説明したように、第2の実施形態の変形例によれば、金属の体積が相転移によって変化し空隙が発生する場合であっても、回転軸部301の回転によって生じる遠心力により導電性を確保することができる。 As described above, according to the modification of the second embodiment, even when the volume of the metal changes due to the phase transition and a void is generated, the conductivity is caused by the centrifugal force generated by the rotation of the rotating shaft portion 301. Can be secured.
　(第3の実施形態)
　図9を図5と対比させながら第3の実施形態について説明する。第1の実施形態では図5に示したように、セラミック製の回転軸部301の一部を金属製である導通部301Aで構成した。これに対し、本実施形態では導通部301Aはそのままとしながら、セラミック製の回転軸部301の一部をセラミック製断熱部材900で構成する。以下、本実施形態と第一の実施形態との差異について詳細に説明し、第一の実施形態と同様の構成については説明を省略する。 (Third embodiment)
A third embodiment will be described while comparing FIG. 9 with FIG. In the first embodiment, as shown in FIG. 5, a part of the ceramic rotating shaft 301 is constituted by a conducting portion 301A made of metal. On the other hand, in the present embodiment, a part of the ceramic rotating shaft 301 is constituted by the ceramic heat insulating member 900 while keeping the conducting portion 301A as it is. Hereinafter, differences between the present embodiment and the first embodiment will be described in detail, and the description of the same configuration as the first embodiment will be omitted.
　図9に示すように、本実施形態の回転軸部301は、陽極212またはスラスト軸受304に接触する部分をセラミック製断熱部材900で構成する。セラミック製断熱部材900は、その他の回転軸部302を構成するセラミック製の部材よりも熱伝導率の小さな部材であり、例えばジルコニア等である。セラミック製断熱部材900と、陽極212や回転軸部301、スラスト軸受304との接合には、拡散接合やメタライズのようなセラミック接合法が用いられる。 As shown in FIG. 9, the rotating shaft portion 301 of the present embodiment is configured by a ceramic heat insulating member 900 at a portion in contact with the anode 212 or the thrust bearing 304. The ceramic heat insulating member 900 is a member having a smaller thermal conductivity than the ceramic members constituting the other rotating shaft portions 302, and is made of, for example, zirconia. For joining the ceramic heat insulating member 900 to the anode 212, the rotating shaft 301, and the thrust bearing 304, a ceramic joining method such as diffusion joining or metallization is used.
　このような構成とすることにより、陽極212と回転軸部301との間、又は回転軸部301と スラスト軸受304との間に、セラミック製断熱部材900を設けることにより、回転軸受、特にスラスト軸受304への熱流入を著しく低減することができる。 With such a configuration, a ceramic heat insulating member 900 is provided between the anode 212 and the rotary shaft portion 301 or between the rotary shaft portion 301 and the saddle thrust bearing 304, so that the rotary bearing, particularly the thrust bearing. Heat inflow to 304 can be significantly reduced.
　また、第1の実施形態と同様に、ラジアル軸受303a、303bはセラミック製であり、スラスト軸受304は金属製であって、回転軸部301の一部が導通部301Aで構成されるので、導電性を確保しながら、回転軸受の摩耗を低減できる。 Further, as in the first embodiment, the radial bearings 303a and 303b are made of ceramic, the thrust bearing 304 is made of metal, and a part of the rotating shaft portion 301 is constituted by the conducting portion 301A. It is possible to reduce the wear of the rotary bearing while ensuring the performance.
　以上、複数の実施形態について説明したが、本発明はこれらの実施形態に限定されるものではない。例えば、第3の実施形態において、導通部301Aを液体金属で構成しても良い。 Although a plurality of embodiments have been described above, the present invention is not limited to these embodiments. For example, in the third embodiment, the conducting part 301A may be made of a liquid metal.
　1　X線CT装置、100　スキャンガントリ部、101　X線管装置、102　回転円盤、103　コリメータ、104　開口部、105　寝台、106　X線検出器、107　データ収集装置、108　ガントリ制御装置、109　寝台制御装置、110　X線制御装置、120　操作卓、121　入力装置、122　画像演算装置、123　記憶装置、124　システム制御装置、125　表示装置、210　X線管、211　陰極、212　陽極、213　外囲器、214　励磁コイル、215　回転体支持部、216　電子線、217　X線、218　放射窓、219　回転軸、220　容器、300　固定部、301　回転軸部、301A　導通部、302　回転円筒部、303a、303b　ラジアル軸受、303b-1　内輪、303b-2　軸受ボール、303b-3　外輪、304　スラスト軸受、304-1　回転側軌道面、304-2　軸受ボール、304-3　固定側軌道面、400　予圧バネ、700　大径部、800　空隙、900　セラミックス製断熱材 1 X-ray CT device, 100 scan gantry unit, 101 X-ray tube device, 102 rotating disk, 103 collimator, 104 opening, 105 bed, 106 X-ray detector, 107 data collection device, 108 gantry control device, 109 bed control Device, 110 X-ray control device, 120 console, 121 input device, 122 image operation device, 123 storage device, 124 system control device, 125 display device, 210 X-ray tube, 211 cathode, 212 anode, 213 envelope, 214 Excitation coil, 215 Rotating body support, 216 Electron beam, 217 X-ray, 218 Radiation window, 219 Rotating shaft, 220 Container, 300 Fixed portion, 301 Rotating shaft portion, 301A Conducting portion, 302 Rotating cylindrical portion, 303a, 303b Radial bearing, 303b-1 inner ring, 303b-2 bearing ball, 303b-3 outer ring, 304 thrust bearing, 304-1 rotating side raceway, 304-2 bearing ball, 304-3 fixed side raceway, 400 preload spring, 700 Large diameter part, 800 void, 900 ceramic Manufacturing heat insulating material

Claims (9)

  1. 　電子線が照射されることでX線を放射する陽極と、前記陽極に接続される回転軸部と、　前記回転軸部を回転可能に支持する回転軸受と、を備え、
    　前記回転軸受は前記回転軸部の外周に配置されるラジアル軸受と前記回転軸部の底面に配置されるスラスト軸受とを有しており、前記ラジアル軸受はセラミック製であり、前記スラスト軸受は金属製であって、前記回転軸部は前記陽極と前記スラスト軸受とを電気的に導通させる導通部を有することを特徴とするX線管装置。     An anode that emits X-rays when irradiated with an electron beam, a rotary shaft connected to the anode, and a rotary bearing that rotatably supports the rotary shaft,
    The rotary bearing includes a radial bearing disposed on an outer periphery of the rotary shaft portion and a thrust bearing disposed on a bottom surface of the rotary shaft portion, the radial bearing is made of ceramic, and the thrust bearing is a metal The X-ray tube apparatus according to claim 1, wherein the rotating shaft portion has a conducting portion that electrically connects the anode and the thrust bearing.
  2. 　請求項1に記載のX線管装置において、前記導通部は、弾性体で構成されることを特徴とするX線管装置。 2. The X-ray tube apparatus according to claim 1, wherein the conducting portion is made of an elastic body.
  3. 　請求項2に記載のX線管装置において、前記弾性体は金属バネであることを特徴とするX線管装置。 3. The X-ray tube apparatus according to claim 2, wherein the elastic body is a metal spring.
  4. 　請求項1に記載のX線管装置において、前記導通部は、前記回転軸部の中に設けられた中空部に充てんされた液体金属によって構成されることを特徴とするX線管装置。 2. The X-ray tube apparatus according to claim 1, wherein the conducting portion is made of a liquid metal filled in a hollow portion provided in the rotating shaft portion.
  5. 　請求項4に記載のX線管装置において、前記液体金属の充てん時の体積は、前記中空部の容積よりも小さいことを特徴とするX線管装置。 5. The X-ray tube apparatus according to claim 4, wherein a volume when the liquid metal is filled is smaller than a volume of the hollow portion.
  6. 　請求項5に記載のX線管装置において、前記中空部は、前記陽極または前記スラスト軸受に接触する部分の外径がそれ以外の外径よりも大きいことを特徴とするX線管装置。 6. The X-ray tube apparatus according to claim 5, wherein the hollow portion has an outer diameter of a portion in contact with the anode or the thrust bearing larger than other outer diameters.
  7. 　請求項1に記載のX線管装置において、前記回転軸部は、前記陽極または前記スラスト軸受に接触する部分の熱伝導率が、それ以外の熱伝導率よりも小さいことを特徴とするX線管装置。 2. The X-ray tube device according to claim 1, wherein the rotary shaft portion has a thermal conductivity of a portion in contact with the anode or the thrust bearing smaller than other thermal conductivity. Tube equipment.
  8. 　請求項7に記載のX線管装置において、
    　前記陽極または前記スラスト軸受に接触する部分はジルコニアであり、前記陽極または前記スラスト軸受に接触する部分以外は窒化ケイ素または炭化ケイ素であることを特徴とするX線管装置。     In the X-ray tube device according to claim 7,
    An X-ray tube apparatus characterized in that a portion that contacts the anode or the thrust bearing is zirconia, and a portion other than the portion that contacts the anode or the thrust bearing is silicon nitride or silicon carbide.
  9. 　被検体にX線を照射するX線源と、前記X線源に対向配置され前記被検体を透過したX線を検出するX線検出器と、前記X線源と前記X線検出器を搭載し前記被検体の周囲を回転する回転円盤と、前記X線検出器により検出された透過X線量に基づき被検体の断層画像を再構成する画像再構成装置と、前記画像再構成装置により再構成された断層画像を表示する画像表示装置と、を備え、
    　前記X線源が請求項1に記載のX線管装置であることを特徴とするX線CT装置。     Equipped with an X-ray source that irradiates the subject with X-rays, an X-ray detector that is disposed opposite to the X-ray source and detects X-rays transmitted through the subject, and the X-ray source and the X-ray detector A rotating disk that rotates around the subject, an image reconstruction device that reconstructs a tomographic image of the subject based on a transmitted X-ray amount detected by the X-ray detector, and a reconstruction performed by the image reconstruction device An image display device for displaying the tomographic image obtained,
    2. An X-ray CT apparatus, wherein the X-ray source is the X-ray tube apparatus according to claim 1.
PCT/JP2017/022294 2016-07-27 2017-06-16 X-ray tube apparatus and x-ray ct apparatus WO2018020895A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2016146851A JP2018018642A (en) 2016-07-27 2016-07-27 X-ray tube device and x-ray ct apparatus
JP2016-146851 2016-07-27

Publications (1)

Publication Number Publication Date
WO2018020895A1 true WO2018020895A1 (en) 2018-02-01

Family

ID=61016911

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2017/022294 WO2018020895A1 (en) 2016-07-27 2017-06-16 X-ray tube apparatus and x-ray ct apparatus

Country Status (2)

Country Link
JP (1) JP2018018642A (en)
WO (1) WO2018020895A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110137061A (en) * 2019-05-31 2019-08-16 麦默真空技术无锡有限公司 A kind of high temperature resistant X ray CT pipe

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP7244149B1 (en) * 2022-09-29 2023-03-22 オルファ株式会社 Circular blade for film cutting

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56144465U (en) * 1980-03-31 1981-10-31
JPS5951442U (en) * 1982-09-28 1984-04-04 株式会社島津製作所 rotating anode x-ray tube
JPH06176720A (en) * 1992-01-24 1994-06-24 Toshiba Corp Rotation anode type x-ray tube
JPH09115467A (en) * 1995-09-28 1997-05-02 Siemens Ag X-ray tube
JP2016133130A (en) * 2015-01-15 2016-07-25 株式会社ジェイテクト Bearing device

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10106461A (en) * 1996-09-30 1998-04-24 Shimadzu Corp Rotary anode type x-ray tube
US5991361A (en) * 1998-01-26 1999-11-23 General Electric Company Bearing assembly for X-ray tube
JP2004502402A (en) * 2000-01-06 2004-01-29 レキシコン・ジェネティクス・インコーポレーテッド Novel human protease and polynucleotide encoding it
JP2003077412A (en) * 2001-08-31 2003-03-14 Toshiba Corp Rotating anode type x-ray tube

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56144465U (en) * 1980-03-31 1981-10-31
JPS5951442U (en) * 1982-09-28 1984-04-04 株式会社島津製作所 rotating anode x-ray tube
JPH06176720A (en) * 1992-01-24 1994-06-24 Toshiba Corp Rotation anode type x-ray tube
JPH09115467A (en) * 1995-09-28 1997-05-02 Siemens Ag X-ray tube
JP2016133130A (en) * 2015-01-15 2016-07-25 株式会社ジェイテクト Bearing device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110137061A (en) * 2019-05-31 2019-08-16 麦默真空技术无锡有限公司 A kind of high temperature resistant X ray CT pipe

Also Published As

Publication number Publication date
JP2018018642A (en) 2018-02-01

Similar Documents

Publication Publication Date Title
CN107078007B (en) X-ray pipe device and X ray CT device
WO2018020895A1 (en) X-ray tube apparatus and x-ray ct apparatus
JP2017091881A (en) X-ray tube apparatus and X-ray CT apparatus
JP6464264B2 (en) X-ray tube apparatus and X-ray CT apparatus
JP5893927B2 (en) X-ray tube apparatus and X-ray CT apparatus
JP6169576B2 (en) Rotating anode type X-ray tube apparatus and X-ray imaging apparatus
JP5890309B2 (en) X-ray tube apparatus and X-ray CT apparatus
JP5959866B2 (en) X-ray tube apparatus and X-ray CT apparatus
JP6008634B2 (en) X-ray tube apparatus and X-ray CT apparatus
JP6798941B2 (en) X-ray tube device and X-ray CT device
JP7433274B2 (en) X-ray tube equipment and X-ray CT equipment
JP2016004766A (en) X-ray tube device and x-ray imaging device
JP5766128B2 (en) X-ray tube apparatus and X-ray CT apparatus
JP5865249B2 (en) X-ray tube apparatus, manufacturing method thereof, and X-ray diagnostic imaging apparatus
JP2022040843A (en) X-ray tube device and x-ray imaging device
JP5574672B2 (en) X-ray tube device and X-ray device
JP6777526B2 (en) X-ray tube device and X-ray CT device
US20240105415A1 (en) X-ray tube assembly and x-ray ct equipment
JP6318147B2 (en) X-ray tube apparatus and X-ray imaging apparatus
JP2018037144A (en) X-ray tube device and x-ray imaging system
JP2016001550A (en) X-ray tube device and x-ray ct device
JP2012104392A (en) X-ray tube device and x-ray ct device

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 17833905

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 17833905

Country of ref document: EP

Kind code of ref document: A1