Abstract: An X-ray apparatus includes a rotation-anode type X-ray tube which is configured such that a rotatable anode target and a cathode that is disposed to be opposed to the anode target are accommodated within a vacuum envelope, a stator which generates an induction electromagnetic field for rotating the anode target, a housing which accommodates and holds at least the rotation-anode type X-ray tube, a circulation path which is provided near at least a part of the rotation-anode type X-ray tube, and through which a water-based coolant is circulated, and a cooling unit including a circulation pump, which is provided at a position along the circulation path and forcibly feeds the water-based coolant, and a radiator which radiates heat of the water-based coolant, wherein at least a part of a surface of a metallic component is coated with a coating member to prevent contacting with the water-based coolant.

Abstract: An anode target (22) is rotatably supported by a rotating mechanism (25) having a rotary body (23) and a stationary body (28). A fitted portion between the rotary body (23) and the stationary body (28) is formed of bearing areas (L1) to (L4) having dynamic pressure type sliding bearings and a non-bearing area (L5) having a clearance between the rotary body (23) and the stationary body (28) larger than that in the bearing areas (L1) to (L4). The rotary body facing the non-bearing area is positioned where a time for heat transfer from the anode target (22) is shorter than the rotary body facing the bearing areas. Thus, the characteristics of heat radiation from the anode target (22) can be improved, and a stable bearing operation can be maintained.

Abstract: A rotary anode X-ray tube, comprising a rotor, a stationary structure, a dynamic pressure slide bearing formed between the rotor and the stationary structure, the stationary structure having a lubricant storage chamber and provided with a lubricant passageway, and a vacuum vessel. Holes are formed in the stationary structure extending from the lower edge surface along the tube axis and not to cross the lubricant storage chamber and the lubricant passageway. Heat transfer members for the stationary structure having a heat conductivity higher than that of the stationary structure are inserted into the holes, respectively. A heat transfer member having a heat conductivity higher than that of the inner cylindrical structure of the rotor is bonded in a cylindrical form to the outer circumferential wall of the inner cylindrical structure constituting a bearing. A heat transfer member can be mounted to each of the rotor and the stationary structure.

Abstract: An x-ray tube apparatus comprises a cathode structure emitting an electron beam, a anode target arranged to face the cathode structure, a rotary structure fixed to the anode target, a stationary shaft having bearings arranged between the stationary shaft and the rotary structure for rotatably supporting the rotary structure, and a vacuum envelope provided with an x-ray transmitting window for taking the X-ray generated from the anode target to the outside. The end portion of the stationary shaft on the side of the cathode structure and the other end portion on the side of the anode terminal are fixed to parts of the vacuum envelope. Particularly, the joining portion on the side of the cathode structure is deviant from the axis of rotation of the anode target and the rotary structure and positioned on the side opposite to the cathode structure and the X-ray transmitting window with respect to the axis of rotation.

Abstract: In an X-ray tomographic apparatus, while rotating a gantry rotary section around a region where an object to be photographed is placed, the anode target of an X-ray tube is rotated at a predetermined high rotation rate and X-rays are emitted from the anode target. In emitting the X-rays, the rotation torque is increased to be larger than that prior to rotation of the gantry rotary section in accordance with the rotation drive power supplied to a stator coil. A decrease in rotation rate of the anode target of the X-ray tube can be prevented even during rotation of the gantry rotary section, radiation at a necessary and sufficient X-ray dose can be assured, and an X-ray tomographic image can be properly obtained.

Abstract: In a rotating anode X-ray tube of this invention, a liquid metal lubricant supplied to bearing portions between a rotary member and a stationary member for instructing rotation of the rotary member is to be filled to a volume having a range of lower limit being an amount to fill bearing gaps, including helical grooves, and as an upper limit being 70% of the capacity of the interior in which the lubricant can flow, measured from the end portion of a helical groove slide bearing portion closest to the interior of a vacuum container. In the rotating anode X-ray tube, leakage of the liquid metal lubricant can be prevented, and a stable bearing operation can be maintained.

Abstract: A rotary anode type X-ray tube comprises a thin gas passageway extending from a lubricant chamber formed along the axis of a stationary structure and open at a fine gap G effective for preventing a lubricant leakage. In manufacturing the tube, a liquid metal lubricant is supplied to the lubricant chamber and to a slide bearing section, followed by assembling the tube and, then, sealing the assembled tube in a vacuum vessel. In the subsequent exhausting step, an open end of the gas passageway is allowed to face upward. The particular exhausting operation permits completely releasing to the outside the gas impregnated in the bearing-constituting members and the liquid metal lubricant, making it possible to maintain a stable bearing function.

Abstract: An X-ray tube of the rotary anode type includes a rotary structure to which an anode target is fixed, a stationary structure fitted into the rotating member, slide bearings arranged between them and provided with spiral grooves, and a lubricant consisting of gallium alloy and supplied to the slide bearings. The rotary structure includes a first rotating member to which the anode target is connected and a second rotating member provided with the bearings. These first and second rotating members are kept coaxial to each other and connected together at their those portions which are remote from the anode target when viewed in the rotating axis direction of the target and along a heat transmitting line extending from the target to the bearings, but heat insulating clearances and are formed between the rotating members at their other portions not connected. The first rotating member is made of one of those materials which have a heat conductivity smaller than 0.1 (cal/cm.sec..degree.C.) at temperature range of 0.

Abstract: A method of manufacturing an X-ray tube comprises the steps of applying the bearing portions with liquid metal lubricant and heating the bearing portions defined by a rotary structure and a stationary shaft to a temperature of 200.degree. C. or more in a vacuum condition. An apparatus for manufacturing an X-ray tube comprises a vacuum bell jar having a heating unit, a metal lubricant injector provided in the vacuum bell jar and a holding and controlling device for holding the rotary structure and the stationary shaft and controlling the movement and the mutual connection of the rotary structure and stationary shaft externally of the vacuum envelope.

Abstract: A rotary-anode X-ray tube having a rotor, a stationary shaft, and a sliding bearing connecting the rotor and the stationary shaft, forming a gap filled with liquid metal lubricant. The rotor has a first rotary member supporting an anode target and a second rotary member at which a sliding bearing is installed and which is coaxial with the first rotary member. The first and the second rotary members are connected at that end of the heat conductive path which is remote from the anode target. A heat insulating gap is formed at all fitting portions, but the remote end. Therefore, the temperature rise of the sliding bearing is controlled without using refregerant, and stable rotation of the bearing is secured.

Abstract: A rotary X-ray tube of the anode type wherein a jacket which serves to prevent lubricant from being scattered into the space in a vacuum envelope is attached to at least one of a rotary structure to which an anode target is fixed and a stationary structure for holding the rotating body, enclosing a clearance opening which forms a border relative to the space in the vacuum envelope.

Abstract: A rotary X-ray tube of the anode type wherein at least one of bearing surfaces which are partly formed on rotary and stationary structures is made of ceramics whose main component is the nitride, boride or carbide of at least one of those deviation metals, except chromium, which belong to a group IVA, VA or VIA element of a period 4, 5 or 6 of the Periodic Table.

Abstract: In a rotary-anode type X-ray tube, a rotary-anode is fixed to a cylindrical rotary structure, and a columnar stationary shaft is fitted in the rotary structure. A gap is formed between the rotary structure and the stationary shaft. The gap is filled with a liquid metal lubricant. Spiral grooves are formed in part of the outer surface of the stationary shaft to form a radial sliding bearing between the stationary shaft and the rotary structure. Spiral grooves are formed in the end faces of the stationary shaft to form a thrust sliding bearing between the stationary shaft and the rotary structure. A recess is formed in the stationary shaft to communicate with gaps in the radial sliding bearing. A lubricant storage chamber for storing the liquid metal lubricant is formed in the stationary shaft along the center axis. The storage chamber communicates with communicating holes which radially extend to be open to an outer surface region, of the stationary shaft, in which no spiral grooves are formed.

Abstract: A rotary-anode type X-ray tube wherein bubbles produced in the gap of a sliding bearing are securely and easily replaced with liquid metal lubricant, and the metal lubricant is prevented from leaking. The rotary anode is secured to a cylindrical rotary structure. A columnar fixed structure is secured to the rotary structure forming a gap between the rotary structure and fixed structure. A liquid metal lubricant fills the gap. Spiral grooves are formed on a part of the outer surface of the fixed structure and the sliding bearing is installed between the fixed structure and the rotary structure. The rotary structure and fixed structure are housed in a vacuum envelope. The gap of the sliding bearing is connected to the space inside the vacuum envelope through an annular space. A gap is formed between a ring block for blocking the opening of the rotary structure and the fixed structure.

Abstract: In a rotary-anode type X-ray tube, a rotary anode is fixed to a cylindrical rotary structure, and a columnar stationary shaft is fit in the rotary structure. A gap is formed between the rotary structure and the stationary shaft, and the gap is filled with a liquid metal lubricant. Spiral grooves are formed in portions of the outer surface of the stationary shaft to form a sliding bearing between the stationary shaft and the rotary structure. Base members of molybdenum, tungsten, niobium, or tantalum, as surface portions, are formed on the inner surface of the rotary structure and the outer surface of the stationary shaft, and reaction layers containing the material for the base member and gallium are respectively formed on the surface portions to a thickness of 1 .mu.m or more.

Abstract: An X-ray image intensifier has an input phosphor screen with a substrate in which a large number of small holes are formed, and a fluorescent material filled in the small holes. A ratio of a maximum inner diameter to a depth of each small hole is set to be 0.5 or less. Alternatively, the input phosphor screen of the X-ray image intensifier of the invention includes a substrate in which a large number of small holes are formed, a low-refractive-index material layer formed on the inner wall of each small hole, and a fluorescent material having a refractive index higher than the low-refractive-index material layer filling each small hole.

Abstract: An X-ray image intensifier has an input phosphor screen with a substrate in which a large number of small holes are formed, and a fluorescent material filled in the small holes. A ratio of a maximum inner diameter to a depth of each small hole is set to be 0.5 or less. Alternatively, the input phosphor screen of the X-ray image intensifier of the invention includes a substrate in which a large number of small holes are formed, a low-refractive-index material layer formed on the inner wall of each small hole, and a fluorescent material having a refractive index higher than the low-refractive-index material layer filling in each small hole.

Abstract: An X-ray image intensifier includes an input screen for converting incident X-ray into photoelectrons. The input screen has a substrate, a phosphor layer having a layer number of columnar crystals of a phosphor formed with gaps therebetween on the substrate, and a photoelectric layer directly or indirectly provided on the phosphor layer. The columnar crystals at a peripheral edge portion of the input screen are thinner than the columnar crystals at a central portion of the input screen.

Abstract: An X-ray image intensifier includes an input screen for converting incident X-rays into photoelectrons, and an output screen for converting the photoelectrons into visible light. The input screen includes a phosphor layer. The phosphor layer has a large number of columnar crystals of a phosphor which have end faces constituting a smooth surface facing the output screen. A low-refractive-index layer is formed on the phosphor layer and made of a material having a refractive index smaller than a refractive index of the phosphor, with respect to the light having a specified wavelength, at which the fluorescence of the phosphor is the most intensive. A photoemissive layer is formed directly or indirectly on the low-refractive-index layer.

Abstract: An X-ray image intensifier comprising a vacuum envelope and an input screen having an improved sensitivity and including a substrate disposed on the X-ray input side of the vacuum envelope, a phosphor layer formed on the substrate and a photocathode formed on the phosphor layer. The phosphor layer consists of columnar crystals extending in a direction perpendicular to the substrate surface. The tip portions of the columnar crystals are deformed to close the upper portion of the clearances formed between the columnar crystals.