JP4173082B2 - X-ray tube device - Google Patents

Description

  The present invention relates to an X-ray tube apparatus used in an X-ray CT (Computed Tomography) apparatus and the like, and more particularly, to an improvement in a rotating anode structure of a rotating anode X-ray tube housed in the X-ray tube apparatus.

An X-ray tube apparatus used in a medical X-ray apparatus such as an X-ray CT apparatus normally contains a rotating anode X-ray tube having a large allowable load capacity. A rotating anode X-ray tube (hereinafter abbreviated as an X-ray tube) has a rotating anode that rotates in a vacuum. The rotating part of the rotating anode, such as a target that generates X-rays, is rotatably supported by a bearing. Has been. Since the bearing of the rotating anode is used at a high temperature in a vacuum, a lubricating oil cannot be used as a lubricant, and a solid lubricant is usually used. As the solid lubricant, a soft metal such as silver or lead, or a compound easily cleaved such as molybdenum disulfide is used. The usage is disclosed in Patent Document 1 and the like. Recently, fluid lubricated bearings using liquid metal have also been adopted. However, it is expensive in terms of cost, and at present, solid lubrication type rotating anodes are mainly used.
JP-A-5-26245

  When a solid lubricant is used for a bearing of a rotating anode, there are problems as described below. First, unlike a lubricating oil, a solid lubricant tends to have a non-uniform thickness of a lubricating film formed on the surface of the ball of the bearing and the ball raceway of the inner ring and the outer ring. If the lubrication film thickness of the bearing is non-uniform, due to the difference in hardness, when the rotating anode rotates in a vacuum, large noise and vibration may occur, which may exceed their regulatory limits. . For this reason, when a solid lubricant is used for the bearing of the rotating anode, various processes have been devised in order to make the lubricating film thickness uniform on the rolling surface of the bearing.

  An example of a process for forming a lubricating film on a bearing is that after a solid lubricant is deposited on the ball or inner ring of the bearing or the ball rolling surface of the outer ring by vapor deposition or application before attaching the bearing to the rotating anode. Rotate the bearing by applying an appropriate load. This rotation of the bearing is called a break-in rotation, and this method is performed in order to increase the adhesion between the bearing base material and the solid lubricant and to level the unevenness on the surface of the bearing. This running-in of the bearing is performed before or during assembly of the rotating anode. The solid lubricant adhering to the bearing by such a process is gradually removed from the bearing during the running-in of the bearing and the use of the X-ray tube. The amount of the solid lubricant falling from the bearing increases with time, but a difference occurs due to a difference in conditions such as the load applied to the bearing and the rotational speed.

  In addition, even when the thickness of the solid lubricant attached to the bearing is uniform and there are no problems such as noise or vibration during rotation, the temperature of the bearing during use of the X-ray tube will reach the melting point of each lubricant. Since the temperature rises to a near temperature, the evaporation amount of the lubricant adhering to the bearing may increase, and the amount of lubricant in the bearing rolling surface and its vicinity may decrease.

  As described above, when the lubricant film thickness of the bearing is reduced due to the lubricant falling off from the bearing or when the amount of lubricant such as the rolling surface of the bearing is reduced, the amount of lubricant is reduced in the X-ray tube. The proper amount necessary for the rotation life may be insufficient, and the lubricant may be depleted in a shorter period than the rotation life planned during the use of the X-ray tube, resulting in malfunction of the bearing.

  In addition, the lubricant that has fallen from the bearing in the X-ray tube (hereinafter referred to as “dropping lubricant”) becomes powder or agglomerate, and remains in the fixed portion that supports the bearing of the rotating anode. Most of these falling lubricants adhere to the surface of the bearing and the inner surface of the fixed portion in the vicinity thereof, but a part of the lubricant moves inside the fixed portion. This moving drop-off lubricant may enter the bearing balls and the rolling surfaces of the inner and outer rings. As a result, normal rotation of the bearings will be hindered, resulting in abnormal rotation such as increased noise, vibration, and rotation stoppage. There is a case.

  In addition, when the amount of the lubricant that falls off increases in the fixed part, the lubricant may come out of the fixed part and move into the X-ray tube via a gap between the fixed part and the rotor. . At this time, if the falling lubricant adheres to the inner surface of the envelope of the X-ray tube or the vicinity of the facing portion between the cathode and the rotating anode, a high voltage is applied between the cathode and the rotating anode of the X-ray tube. When it is done, it will cause discharge.

  As explained above, in the rotary anode X-ray tube inserted in the X-ray tube device, in order to improve the adhesion of the solid lubricant of the bearing which is widely used at present and to make the formed lubricating film thickness uniform. Although various process improvements have been made, characteristics such as the adhesion of the lubricant to the rolling surface of the bearing are affected by various factors, and it is difficult to completely stabilize these characteristics. .

  As described above, the falling lubricant that has fallen from the bearing generates rotation noise and vibration of the X-ray tube to reduce the rotation life, and also causes discharge in the X-ray tube to reduce the withstand voltage life. This is a factor that reduces the product reliability of pipes. For this reason, in the present invention, in the manufacturing process of the rotary anode of the X-ray tube, the lubrication performance of the bearing is determined by grasping the falling state and amount of the lubricant from the bearing in the rotating anode and removing the falling lubricant. The purpose is to improve the reliability of the product by suppressing the manufacturing variability and extending the rotational life and voltage endurance life of the X-ray tube.

  In order to achieve the above object, the X-ray tube apparatus of the present invention is a connection that combines a disk-shaped target serving as an X-ray source, a small-diameter portion that supports the target, and a cylindrical and highly conductive large-diameter portion. A rotor having a portion, a rotating shaft that supports the rotor at its connecting portion, a bearing that rotatably supports the rotating shaft, a fixed portion that has a cylindrical portion and supports the bearing on the inner peripheral side thereof, and the rotor A rotating anode having a magnetic portion made of a ferromagnetic material disposed between a large diameter portion of the magnet and a cylindrical portion of the fixed portion, and electrons for forming a focal point serving as an X-ray source on the target of the rotating anode A rotating anode X-ray tube with a cathode that discharges the current, and an envelope that insulates and supports the rotating anode and the cathode and is sealed in a vacuum-tight manner is insulated in an X-ray tube and an electric shock-proof X-ray tube container. In an X-ray tube apparatus that is immersed and stored in oil, the rotating positive electrode on the side of the cylindrical portion of the fixed portion of the rotating anode A hole penetrating through the hollow portion inside the cylindrical portion is provided at a position where it can be seen from the outside during pole assembly, and the hole of the fixed portion is closed by a lid at the stage of assembling the rotating anode. (Claim 1).

  In this configuration, a hole that penetrates the hollow portion in the fixed portion is provided at a position on the side surface of the cylindrical portion of the fixed portion of the rotating anode of the X-ray tube that is visible from the outside, so the bearing is supported from this hole. It is possible to look into the hollow portion in the cylindrical portion. As a result, after assembling the rotating anode and rotating the bearings, it is possible to grasp the state of lubricant adhesion from the hole to the hollow part of the fixed part, and the lubricant that has fallen from the hole to the hollow part of the fixed part. The agent can be taken out, and the amount of dropout can be measured and the lubricant removed. These data concerning the drop-off lubricant can be used as management data for the rotation performance of the bearing and data for improving the rotation performance, and the removal of the drop-off lubricant contributes to the improvement of the rotation life and the withstand voltage life. Furthermore, by covering the hole of the fixing portion, the movement of the falling lubricant into the X-ray tube can be suppressed, and the withstand voltage life can be improved.

  In the X-ray tube device of the present invention, the hole of the fixed portion of the rotating anode is formed near the bottom of the hollow portion inside the fixed portion. In this configuration, since the hole of the fixing portion is formed in the vicinity of the bottom portion of the hollow portion that accommodates the bearing or the like, the bottom portion of the hollow portion and its peripheral portion can be seen through the hole of the fixing portion. The bottom part of the hollow part is a place where the falling lubricant that has fallen off from the bearing is likely to accumulate. It can be easily taken out.

  Further, in the X-ray tube apparatus of the present invention, the lid that closes the hole of the fixed portion of the rotating anode can be opened and closed until the end of the assembly of the rotating anode. In this configuration, the lid that closes the hole in the fixed portion can be opened and closed during the assembly of the rotating anode, so that the dropout lubrication in the hollow portion that houses the bearing in the fixed portion after the running-in rotation of the bearing during assembly of the rotating anode It is possible to observe the adhesion state of the agent, measure the removal amount, remove it, etc. through the hole in the fixed part, and then close the hole with a lid to reduce the leakage of the falling lubricant while using the X-ray tube Can do.

  In the X-ray tube device of the present invention, the hole of the fixed portion of the rotary anode is a screw hole, and the screw hole is closed with a lid having the same thread cut on a part of the outer periphery. In this configuration, the hole of the fixed part has a screw hole structure, and a screw structure lid is fitted into this hole, so by screwing the lid when the hole is closed and removing the lid when the hole is opened, The hole of the fixing part can be easily opened and closed.

  In the X-ray tube device of the present invention, the magnetic part of the rotating anode is movably attached to a position on the outer periphery of the cylindrical part of the fixed part so as to cover the hole of the fixed part, and the magnetic part The opening and closing of the hole of the fixed portion is performed by moving the. In this configuration, since the magnetic part disposed between the rotor of the rotating anode and the fixed part is used as a lid for the hole of the fixed part, the present invention can be implemented without adding other components. The opening and closing of the hole of the fixed part is performed by moving the magnetic part along the outer periphery of the fixed part.

  In the X-ray tube device of the present invention, the hole is opened and closed by moving the magnetic part backward and forward toward the hole in the central axis direction of the cylindrical part of the fixed part. In this configuration, the opening and closing of the hole of the fixed part is performed by moving the magnetic part in the direction of the central axis of the fixed part. The hole is closed by moving the magnetic part to the anode end side, and the hole is opened by moving the magnetic part to the target side.

  Further, in the X-ray tube device of the present invention, the magnetic portion can be rotated and slid along the outer periphery of the cylindrical portion of the fixed portion, and the hole is substantially at a position corresponding to the hole of the fixed portion of the magnetic portion. Opening and closing the hole of the fixed part by providing a connecting hole of the same size, rotating and sliding the magnetic part, matching the connecting hole with the hole of the fixed part, and completely shifting Is to do. In this configuration, the opening and closing of the hole of the fixed part is performed by rotating and sliding the magnetic part along the outer periphery of the fixed part. This is particularly effective when there is no dimensional allowance for movement along the direction of the central axis of the fixed part, such as when the length of the magnetic part is long or the length of the fixed part is short.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
1 and 2 are structural views of a first embodiment of an X-ray tube apparatus according to the present invention. FIG. 1 is a structural diagram of the entire X-ray tube apparatus, and FIG. 2 is a structural diagram of a rotating anode which is a main part of the present invention. The present invention is characterized by the structure of the rotary anode of the rotary anode X-ray tube inserted in the X-ray tube apparatus. Hereinafter, the overall structure and main part structure of this embodiment will be described with reference to FIGS.

  In FIG. 1, an X-ray tube device 10 of this embodiment includes a rotating anode X-ray tube (hereinafter abbreviated as an X-ray tube) 14 serving as an X-ray generation source in an X-ray tube container 12, and an X-ray tube 14. A stator 18 that rotationally drives the rotating anode (hereinafter also referred to simply as an anode) 16, a cathode-side support 20 that insulates and supports the cathode side of the X-ray tube 14, and an insulating support that supports the anode side of the X-ray tube 14 An anode side support 22 that performs power supply, a cathode side cable receptacle 26 that feeds a negative high voltage to the cathode 24 of the X-ray tube 14, and an anode side that feeds a positive high voltage to the rotating anode 16 of the X-ray tube 14 The cable receptacle 28 is insulated from the X-ray tube 14 and the like, and includes an insulating oil 30 and the like for cooling.

  Next, the structure of the X-ray tube 14 will be described. The X-ray tube 14 includes a cathode 24 that generates thermoelectrons, a rotary anode 16 that generates X-rays when the thermoelectrons from the cathode 24 collide, and the cathode 24 and the rotary anode 16 are vacuum-tightly enclosed and insulated. And an envelope 32 to be supported.

  The cathode 24 includes a filament 24a that is heated to emit thermoelectrons, a focusing electrode 24b that focuses the thermoelectrons to form a focal point 34 on the rotating anode 16, a holder 24c that supports the focusing electrode 24b, and a holder 24c. It is composed of a stem 24d for insulating support. Most of the stem 24d is made of an insulating material such as glass or ceramic, and a plurality of stem leads 36 are embedded in the center thereof. The stem lead 36 is connected to the filament 24 a and the holder 24 b inside the X-ray tube 14, and is connected to the cathode lead 38 from the cathode side cable receptacle 26 outside the X-ray tube 14. Via this cathode lead 38, a high voltage having a negative potential is supplied to the focusing electrode 24b and the holder 24c, and a filament heating voltage is supplied to the filament 24a.

  The rotating anode 16 receives a thermoelectron from the cathode 24 as a focal point and generates a X-ray, a rotor 42 that supports the target 40 and rotates by receiving a rotational driving force from the stator 18, and supports the rotor 42. A rotating shaft 44, a bearing 46 that rotatably supports the rotating shaft 44, a fixed portion 48 that supports the bearing 46, and a heat insulating portion 50 that connects the rotor 42 and the rotating shaft 44 to reduce heat transfer to the rotating shaft 44. And a magnetic part 56 that is disposed between the fixed part 48 and the rotor 42 and serves to collect a rotating magnetic field from the stator 18.

  The envelope 32 includes a large-diameter portion 32a that is located in the center and encloses the target 40, a cathode insulating portion 32b that insulates and supports the cathode 24, an anode insulating portion 32c that insulates and supports the rotating anode 16, and the like. The large-diameter portion 32a is made of a metal material such as copper or stainless steel, and an X-ray emission window 58 is attached at a position close to the focal point 34 on the target 40 on the side surface. The X-ray emission window 58 is a window for extracting X-rays to the outside. The X-ray emission window 58 is made of a material having good X-ray permeability such as beryllium and is coupled to the large diameter portion 32a by brazing or welding. The main part of the cathode insulating part 32b is made of an insulating material such as glass or ceramic, one end is connected to the large diameter part 32a, and the other end is connected to the stem 24d of the cathode 24. The main part of the anode insulating part 32c is also made of an insulator such as glass or ceramic, one end is connected to the large diameter part 32a, and the other end is connected to the fixed part 48 of the rotating anode 16.

  Further, on the anode side of the X-ray tube 14, the anode end 48b of the fixed portion 48 of the rotary anode 16 is supported by the anode side support 22 and the anode lead 54 from the anode side cable receptacle 28 is connected. A positive high voltage is supplied via the anode lead 54.

  Next, the details of the structure of the rotating anode, which is the main part of the present embodiment, will be described with reference to FIG. In FIG. 2, FIG. 2 (a) is a structural diagram of the entire rotating anode, and FIGS. 2 (b) and 2 (c) are enlarged views of main parts. First, the entire structure of the rotating anode will be described with reference to FIG. In FIG. 2 (a), the target 40 of the rotating anode 16 of the present embodiment is a disc-shaped body made of tungsten or a tungsten alloy, and a molybdenum plate or a graphite plate is lined on the back surface to increase the heat capacity of the target. Has been. The target 40 is disposed to face the focusing electrode 24b of the cathode 24, and a focal point 34 is formed on an inclined surface facing the focusing electrode 24b. The rotor 42 includes a narrow-diameter portion 42a that supports the target 40, a large-diameter portion 42b that receives a rotational driving force from the stator 18 disposed outside the X-ray tube 14, and a connection portion 42c that couples the two. . The small-diameter portion 42a of the rotor 42 is made of a highly heat-resistant and high-strength metal material such as molybdenum, and the large-diameter portion 42b is cylindrical and made of a highly conductive metal material such as copper. The connection portion 42c of the rotor 42 is made of a high-strength metal material and is coupled to the small diameter portion 42a and the large diameter portion 42b by brazing or the like.

  The rotor 42 and the rotating shaft 44 are coupled at a connection portion 42c of the rotor 42. The rotor 42 may be coupled directly to the rotating shaft 44, or the heat insulating portion 50 may be inserted between the two. In the latter case, the heat insulating part 50 increases the thermal resistance between the rotor 42 and the rotating shaft 44 so that the heat generated in the target 40 is not transmitted to the bearing 46 as much as possible. Therefore, the heat insulating part 50 has a thin cylindrical part and is made of stainless steel having a low thermal conductivity. This heat insulating part 50 is usually applied when the heat capacity of the rotary anode 16 of the X-ray tube is large. In this embodiment, the latter structure is adopted.

  The rotating shaft 44 has a disk-shaped flange portion 44a coupled to the rotor 42 or the heat insulating portion 50, and a small diameter portion 44b coupled to the two bearings 46, and is made of a high strength steel material or the like. The bearing 46 includes an outer ring, an inner ring, a ball, and the like, and is made of a high-strength steel material. Lubricant is attached to the surface of the ball, the outer ring, and the rolling surface of the inner ring with an appropriate film thickness. As the lubricant, considering that it is used in a vacuum, a soft metal such as silver or lead or a compound easily cleaved such as molybdenum disulfide is used. The inner ring of the bearing 46 may be omitted by providing a rolling surface of the inner ring on the surface of the small diameter portion 44b of the rotating shaft 44. The rotating shaft 44 illustrated in FIG. 2A is also an example of this. Two bearings 46 are used, and are attached to the small-diameter portion 44b of the rotating shaft 44 at an appropriate interval. The bearing 46 is fixed to the wall surface of the hollow portion 52 of the fixed portion 48.

  The fixed portion 48 includes a cylindrical portion 48a that supports the bearing 46, an anode end 48b that serves as a support portion for the entire rotating anode 16, a ring portion 48c that is connected to the anode insulating portion 32c of the envelope 32, and the like. The cylindrical portion 48a and the anode end 48b are usually made integrally and are made of a metal material such as copper or stainless steel. The inside of the cylindrical part 48a forms a hollow part 52, and the bottom part 62 is located in the vicinity of the root of the anode end 48b. The rotating shaft 44 and the bearing 46 are accommodated in the hollow portion 52 inside the cylindrical portion 48a of the fixed portion 48, and the outer rings of the two bearings 46 are fixed to the wall surface of the hollow portion 52 with appropriate intervals.

  A cylindrical magnetic part 56 is disposed between the cylindrical part 48a of the fixed part 48 and the large diameter part 42b of the rotor 42. The magnetic part 56 is made of a ferromagnetic metal material such as iron and serves to collect a rotating magnetic field from the stator 18. The magnetic portion 56 is fixed to the cylindrical portion 48a of the fixed portion 48 or the large diameter portion 42b of the rotor 42. In this embodiment, the magnetic portion 56 is fixed to the outer periphery of the cylindrical portion 48a of the fixed portion 48. The thickness of the magnetic portion 56 is about 1 mm (about 0.5 mm to 3 mm), and the length on the anode end 48b side is slightly longer than the end on the anode end 48b side of the large diameter portion 42b of the rotor 42, for example, 5 Extends ~ 10mm.

  Next, with reference to FIG. 2 (a), the structure of the fixed portion 48 of the rotary anode 16, which is a main part of the present embodiment, and the surrounding structure will be described with reference to FIGS. 2 (b) and 2 (c). To do. In this embodiment, a hole 60 is provided on the side surface of the cylindrical portion 48a of the fixed portion 48 so that the hollow portion 52 can be seen through the inside, and a magnetic portion 56 disposed on the outer periphery of the fixed portion 48 is used as a lid. ing. 2B shows a state where the hole 60 of the fixing portion 48 is opened, and FIG. 2C shows a state where the hole 60 of the fixing portion 48 is closed by the magnetic portion 56.

  2A and 2B, the hollow portion 52 that accommodates the rotating shaft 44, the bearing 46, and the like is provided inside the cylindrical portion 48a of the fixed portion 48 as described above. The hollow portion 52 extends to a portion near the base of the anode end 48, and a substantially flat bottom portion 62 exists at the end portion. A hole 60 penetrating through the hollow portion 52 is formed in the side surface of the cylindrical portion 48a of the fixed portion 48. The hole 60 is circular with a diameter of about 5 mm. The dimension of the hole 60 is not limited to a diameter of 5 mm, and may be increased or decreased as necessary. However, since the hole 60 is for looking into the inside of the hollow portion 52, it is advantageous that the hole 60 is as large as possible. The shape of the hole 60 is not limited to a circle and may be a polygon, but a circle is advantageous from the viewpoint of workability. The position of the hole 60 is preferably in the vicinity of the bottom 62 of the hollow portion 52 so that the state of the bottom 62 can be observed from the outside through the hole 60. Further, in the positional relationship with the end of the large-diameter portion 42b of the rotor 42, the hole 60 can be seen from the outside even when the rotary anode 16 is assembled, so that the anode end 48b from the end of the large-diameter portion 42b of the rotor 42 Must be located on the side.

  The magnetic part 56 serving as a lid for the hole 60 of the fixing part 48 is attached to the outer periphery of the cylindrical part 48a of the fixing part 48, and is moved in the direction of the central axis of the fixing part 48 on the outer periphery. The cylindrical portion 48a of the portion 48 is made to be slidable between the outer diameter of the cylindrical portion 48a. A countersink 66 for fixing to the outer periphery of the fixing part 48 is provided at the end of the magnetic part 56 on the anode end 48b side. Corresponding to the countersink 66, a screw hole 64 for fixing the magnetic part 56 is provided at a position close to the hole 60 on the outer peripheral side surface of the fixing part 48. In the illustrated case, the position of the screw hole 64 is closer to the anode end 48b than the hole 60. However, the position is not limited to this, and the screw hole 64 may be in the same circumferential position as the position of the hole 60. It is only necessary that the countersunk screw is arranged in a range that does not cover the large-diameter portion 42b of the rotor 42.

  FIG. 2 (c) shows a state where the hole 60 of the fixing portion 48 is closed. In FIG. 2 (c), the magnetic part 56 is slid and moved to the anode end 48b side on the outer periphery of the fixing part 48, and is fixed to the outer periphery of the fixing part 48 by a countersunk screw 68 in FIG. 2 (b). As a result, the hole 60 of the fixing portion 48 is closed. The state shown in FIG. 2 (c) corresponds to the state when the assembly of the normal rotating anode 16 is completed. Here, a countersunk screw 68 having a diameter of about 3 mm is used as a screw for fixing the magnetic part 56. However, the screw is not limited to this, and a screw with a different dimension may be used, or another type of screw is used. Needless to say.

  The rotating anode 16 of the X-ray tube apparatus 10 of the present embodiment is assembled as shown in FIG. 2 (c) at the time of assembly, and can be formed as shown in FIG. 2 (b) after assembly. That is, at the time of assembly, as shown in FIG. 2 (c), the magnetic part 56 is disposed at a regular position on the outer periphery of the fixing part 48 and fixed by a flat head screw 68, so that the hollow part 52 of the fixing part 48 is externally attached. The hole 60 leading to is closed. Furthermore, even after assembly, by removing the flat head screw 68 and moving the magnetic part 56 to the target 40 side, a hole 60 appears, and it is possible to look inside the hollow part 52 of the fixed part 48 through this hole 60. Become.

  Next, the effect of the present embodiment will be described. In the assembly process of the rotary anode 16 of the X-ray tube 12 of the present embodiment, after attaching a lubricant to the bearing 46, the bearing 46 is attached to the small-diameter portion 44b of the rotary shaft 44, and the hollow portion of the fixed portion 48 Insert into 52 and secure. Thereafter, after attaching the magnetic part 56 to the outer periphery of the fixed part 48, the rotor 42 is coupled to the flange part 44a of the rotating shaft 44. (In the case of using the heat insulating portion 50, it is inserted between the flange portion 44a of the rotating shaft 44 and the connecting portion 42c of the rotor 42.) Finally, the target 40 is rotated by being attached to the small diameter portion 42a of the rotor 42. The assembly of the anode 16 is completed.

  After the rotary anode 16 is assembled, in order to improve the adhesion of the lubricant to the bearing 46, the rotary anode 16 is conditioned. As the rotating atmosphere, an atmosphere that does not deteriorate the lubricant, such as nitrogen gas or vacuum, is used. Due to this running-in rotation, the lubricant of the bearing 46 adheres well to the rolling surfaces of the ball, the inner ring, and the outer ring, and a part of the extra lubricant is dropped from the bearing 46, and the inside of the hollow portion 52 of the fixed portion 48 It adheres to the inner surface of the part and the hollow part 52. After running-in rotation, holding the rotating anode 16 in a vertical position where the target 40 is on the upper side and striking or vibrating the rotating anode 16 to give an impact to the rotating anode 16, of the above-mentioned dropped lubricant Most of them fall to the bottom 62 of the hollow part 52 of the fixed part 48 and accumulate.

  In this state, the countersunk screw 68 fixing the magnetic part 56 is removed and the magnetic part 56 is moved to the target 40 side, so that a hole 60 appears. The bottom portion 62 and its surroundings can be seen, and the state of lubricant dropping can be confirmed. Here, the data such as the amount of lubricant that has been confirmed (those that have fallen to the bottom 62) and the adhesion status of the lubricant around the bottom 62 are indicators related to the rotational performance of the individual rotating anodes 16. Available. Further, these data can be fed back to the manufacturing process of the rotating anode 16 and used for improving the rotating performance as management data of the rotating performance of the rotating anode 16. As a result, it is possible to improve the reliability of the rotation performance of the rotary anode 16.

  Further, the falling lubricant that has dropped onto the bottom 62 in the hollow portion 52 of the fixed portion 48 is taken out from the hole 60 and removed. About the falling lubricant taken out to the outside, measurement such as weight and appearance inspection are usually performed. These data are used as management data for the rotational performance of the rotary anode 16 as described above. After removal of the falling lubricant, the magnetic portion 56 is moved again to the anode end 48b side, and is fixed to the fixing portion 48 with a flat head screw 68 to close the hole 60.

  By the above-described removal lubricant removal operation, the amount of the removal lubricant remaining in the hollow portion 52 of the fixed portion 48 when the rotary anode 16 is assembled can be drastically reduced. As a result, the amount of falling lubricant that leaks into the X-ray tube 12 from the hollow portion 52 of the fixed portion 48 of the conventional rotating anode 16 through the gap between the rotor 42, the fixed portion 48, and the magnetic portion 56 is drastically reduced. Therefore, the discharge in the X-ray tube 12 generated due to the falling lubricant can be drastically reduced, and the withstand voltage characteristics of the X-ray tube device 10 can be greatly improved.

  In addition, the confirmation work of the lubricant falling state is not only after the turning-in rotation of the rotating anode 16, but also at the time of adjusting the rotating balance of the rotating anode 16, or after the work of rotating the rotating anode 16 during the manufacturing process. Can be done as needed.

  Next, a second embodiment of the X-ray tube apparatus according to the present invention will be described. Since this embodiment has almost the same structure as the first embodiment except for the structure of the rotating anode of the rotating anode X-ray tube inserted in the X-ray tube apparatus, FIG. 3 is used below. Now, the structure of the rotating anode of this embodiment will be described. FIG. 3 shows a cross-sectional view of the main part of the rotating anode of this example. In FIG. 3, FIG. 3 (a) is a cross-sectional view in the X-ray tube axial direction near the fixed portion of the rotating anode, and FIGS. 3 (b) and 3 (c) are AA ′ lines in FIG. 3 (a). FIG. 3 (b) shows a state where the hole provided in the fixing portion is covered, and FIG. 3 (c) shows a state where the hole provided in the fixing portion is opened. In FIG. 3 (a), the rotary anode 70 of this embodiment is composed of a target 40, a rotor 42, a rotary shaft 44, a bearing 46, a fixed portion 48, a magnetic portion 72, and the like, as in the first embodiment. The target 40, the rotor 42, the rotating shaft 44, the bearing 46, and the fixed portion 48 have substantially the same structure as that of the first embodiment, and only the structure of the magnetic portion 72 is different.

  In FIG. 3 (a) to FIG. 3 (c), a hole 60 is provided on the side surface of the cylindrical portion 48a of the fixed portion 48 in the vicinity of the bottom portion 62 of the hollow portion 52, as in the first embodiment. The magnetic part 72 is provided with a connecting hole 74 having the same diameter as the hole 60. The connecting hole 74 of the magnetic part 72 is provided at the end of the magnetic part 56 on the anode end 48b side, and the connecting part 74 is rotated by sliding the magnetic part 72 on the outer periphery of the cylindrical part 48 of the fixed part 48. 74 and the hole 60 of the fixing portion 48 are connected to each other. Further, a screw hole 64 is provided in the vicinity of the bottom 62 of the hollow part 52 of the fixed part 48, and a countersink 66 is provided at the end of the magnetic part 72.

  In the rotary anode 70 of the X-ray tube apparatus of the present embodiment, when assembling the magnetic part 72 on the outer periphery of the cylindrical part 48a of the fixed part 48, as shown in FIGS. 3 (a) and 3 (b), The magnetic part 72 is fixed by the countersunk screw 68 so that the hole 60 of the fixing part 48 is closed. After the rotating anode 70 is assembled, after rotating the bearing 46 such as running-in, the flat head screw 68 is removed and the magnetic part 72 is rotated and slid as shown in FIG. By superimposing the connecting holes 74 provided in the magnetic part 72 on the 48 holes 60, the inside of the hollow part 52 of the fixed part 48 can be observed. In the observation of the hollow portion 52, as in the first embodiment, the state of adhesion of the lubricant dropped to the bottom portion 62 of the hollow portion 52 and the vicinity thereof, the measurement of the amount of the lubricant dropped on the bottom portion 62, Removal is performed. After observing the hollow portion 52, the magnetic portion 72 is rotated and slid back to the original position, and fixed with a flat head screw 68.

  In this embodiment, the magnetic portion 56 is not moved in the direction of the central axis of the fixed portion 48 as in the first embodiment, but the magnetic portion 72 is merely slid around the fixed portion 48, and the fixed portion 48 is moved. It is possible to close or open the hole 60 of the. Therefore, when it is difficult to move the magnetic part 72 in the direction of the central axis of the fixed part 48, such as when the length of the cylindrical part 48a of the fixed part 48 is short or when the length of the magnetic part 72 is long, etc. This embodiment is particularly effective.

  Next, a third embodiment of the X-ray tube apparatus according to the present invention will be described. FIG. 4 shows a cross-sectional view of the main part of the rotating anode of this example. This embodiment also has substantially the same structure as the first embodiment except for the structure of the rotating anode of the rotating anode X-ray tube inserted in the X-ray tube apparatus. Hereinafter, the structure of the rotating anode will be described mainly with reference to FIG. In Fig. 4, Fig. 4 (a) is a cross-sectional view in the X-ray tube axis direction near the fixed part of the rotating anode, and Figs. 4 (b) and 4 (c) are near the hole of the fixed part in Fig. 4 (a). FIG. FIG. 4 (b) shows a state where the hole provided in the fixing portion is covered, and FIG. 4 (c) shows a state where the hole provided in the fixing portion is opened. In FIG. 4 (a), the rotary anode 80 of this embodiment is composed of a target 40, a rotor 42, a rotary shaft 44, a bearing 46, a fixed portion 48, a magnetic portion 82, and the like, as in the first embodiment. . The target 40, the rotor 42, the rotating shaft 44, and the bearing 46 have substantially the same structure as that of the first embodiment, and the structures of the fixed portion 48 and the magnetic portion 82 are different.

  4 (a) to 4 (c), a hole 84 having a shape different from that of the first embodiment is provided on the side surface of the cylindrical portion 48a of the fixed portion 48 at a position close to the bottom portion 62 of the hollow portion 52. It has been. The hole 84 includes a counterbore hole 84a and a screw hole 84b, and the diameter of the screw hole 84b is substantially the same as the diameter of the hole 60 of the first embodiment. 4A and 4B, a lid 86 is attached to the hole 84, and the hole 84 is closed. The lid 86 has a flange portion 86a at the upper portion, a screw portion 86b at the lower portion, and a slit-like groove 86c on the upper surface of the flange portion 86a. The screw portion 86b is fitted into the screw hole 84b of the hole 84 of the fixing portion 48, and the slit 86 The hole 84 is closed by tightening using the groove 86c.

  In FIG. 4C, the lid 86 is removed from the hole 84 of the fixing portion 48, and the hole 84 is in an open state. The magnetic part 82 has a length in the central axis direction slightly shorter than that of the first and second embodiments. When the magnetic part 82 is attached to the outer periphery of the cylindrical part 48 of the fixing part 48, the end on the hole 84 side is provided. The dimension is such that the portion does not reach the hole 84. Further, the attachment of the magnetic part 82 to the outer periphery of the fixed part 48 is performed together when the rotating shaft 44, the bearing 46, and the like are incorporated into the hollow part 52 of the fixed part 48, and remains fixed. The magnetic part 82 is fixed with a flat head screw or the like as in the other embodiments.

  In the rotary anode 80 of the X-ray tube apparatus of the present embodiment, at the time of assembly, as shown in FIGS. 4 (a) and 4 (b), the lid 86 is screwed into the hole 84 of the fixed portion 48, thereby fixing the fixed portion 48. Block the hole 84. After the rotating anode 80 is assembled, after rotating the bearing 46 such as running-in, as shown in FIG. 4 (c), the lid 86 is removed and the hole 84 is opened to fix the fixed portion 48. The inside of the hollow portion 52 can be observed. In the observation of the hollow portion 52, as in the other examples, the observation of the state of adhesion of the falling lubricant to the bottom portion 62 of the hollow portion 52 and the vicinity thereof, the measurement of the amount of the falling lubricant falling on the bottom portion 62, Removal is performed. After observing the hollow portion 52, a lid 86 is attached to the hole 84 of the fixing portion 48 to close it.

  In this embodiment, by attaching or removing the lid 86 to or from the hole 84 of the fixing portion 48, the hole 84 penetrating the hollow portion 52 of the fixing portion 48 can be closed or opened. Through the hole 84, it is possible to manage the lubrication state of the bearing 46 and remove the fallen lubricant after the turning-in of the rotary anode 80. As a result, it is possible to improve the rotational life of the X-ray tube and prevent discharge due to the falling lubricant in the X-ray tube.

  As described above, according to the present invention, a hole penetrating a hollow portion that accommodates a rotating shaft and a bearing is formed in a side surface of a fixed portion that constitutes a rotating anode of a rotating anode X-ray tube inserted in an X-ray tube device. Since the lid for closing it is provided, the inside of the hollow portion of the fixed portion can be observed during the production of the rotary anode. As a result, after the break-in of the bearing during manufacture of the rotating anode, etc., the lid is opened to observe the state of bearing lubricant falling off in the hollow part of the fixed part, to measure the amount of falling lubricant, and to remove the falling lubricant. It is possible to improve the rotational life of the X-ray tube and reduce the discharge in the X-ray tube directly, and indirectly feed it back to the manufacturing process of the rotating anode as management data. By doing so, it is possible to suppress manufacturing variations related to the rotation performance and discharge prevention of the X-ray tube, and to improve the reliability of the product. In addition, since the hole is covered after observation in the hollow part of the fixed part, the amount of lubricant that leaks out from the hollow part of the fixed part is drastically reduced, greatly contributing to the reduction of the discharge of the X-ray tube. To do.

  Further, according to the present invention, a hole penetrating the hollow portion is provided in the side surface of the fixed portion of the rotating anode, and the magnetic portion disposed on the outer periphery of the fixed portion is opened or closed in the direction of the central axis of the fixed portion or Since it is performed by moving in the circumferential direction, the inside of the hollow portion of the fixed portion can be observed during the production of the rotating anode without providing a special lid component.

1 is a structural diagram of a first embodiment of an X-ray tube apparatus according to the present invention. FIG. 3 is a structural diagram of a rotating anode that is a main part of the first embodiment. Sectional drawing of the principal part of the rotating anode of 2nd Example of the X-ray tube apparatus which concerns on this invention. Sectional drawing of the principal part of the rotating anode of the 3rd Example of the X-ray tube apparatus which concerns on this invention.

Explanation of symbols

10 ... X-ray tube equipment
12 ... Rotary anode X-ray tube (X-ray tube)
14 ... X-ray tube container
16, 70, 80 ... Rotating anode (anode)
18 ... Stator
24 ... Cathode
32 ... Envelope
40 ・ ・ ・ Target
42 Rotor
42b ・ ・ ・ large diameter part
44 ・ ・ ・ Rotation axis
46 ・ ・ ・ Bearings
48 ・ ・ ・ Fixing part
48a ... Cylindrical part
48b ・ ・ ・ Anode end
50 ・ ・ ・ Heat insulation
52 ・ ・ ・ Hollow part
56, 72, 84 ... Magnetic part
60, 84 ... holes
62 ... Bottom
64 ... Screw hole
66 ... Countersink
68 ... Flat head screw
74 ... Connection hole
86 ・ ・ ・ Lid

Claims (8)

Disk-shaped target as the X-ray source, a rotor and a connection portion for coupling the large diameter portion and both the high conductivity in the small-diameter portion and a cylindrical supporting the target, the rotor at a connection of the rotor rotary shaft supporting bearing for rotatably supporting the rotary shaft, a fixed portion for supporting the bearing has a cylindrical portion at the inner circumferential side of the cylindrical portion, and the large diameter portion of said rotor and said stationary portion A rotating anode having a magnetic part made of a ferromagnetic material disposed between the cylindrical part, a cathode for emitting an electron current for forming a focal point serving as an X-ray source on the target of the rotating anode, A rotating anode X-ray tube having an envelope that insulates and supports the rotating anode and the cathode and is hermetically sealed in a vacuum-tight manner is immersed in an X-ray tube and an electric shock structure X-ray tube container with insulating oil. An X-ray tube device for storing,
A hole provided in a side surface of the cylindrical portion of the fixed portion of the rotating anode, and penetrating through a hollow portion inside the cylindrical portion;
Cover means for freely opening and closing the hole,
The X-ray tube apparatus according to claim 1, wherein the hole is positioned closer to an anode end of the rotating anode than an end portion of the large diameter portion of the rotor . The X-ray tube apparatus according to claim 1,
The hole is provided at a position where the end of the hollow portion on the anode end side of the rotary anode can be visually observed from the outside through the hole.
X-ray tube device characterized by the above . The X-ray tube apparatus according to claim 1 or 2,
The lid means is realized by the magnetic part,
The magnetic part has a cylindrical shape, is rotatably disposed on the outer periphery of the cylindrical part, and includes a connecting hole that penetrates the magnetic part and has approximately the same size as the hole.
The connecting hole is provided at substantially the same position as the hole with respect to the central axis direction of the cylindrical portion.
X-ray tube device characterized by the above . The X-ray tube apparatus according to claim 1 or 2,
The hole includes a counterbore hole and a screw hole,
The lid means has a flange portion that fits into a counterbore hole and a screw portion that fits into the screw hole.
X-ray tube device characterized by the above . The X-ray tube apparatus according to claim 1 or 2,
The lid means is realized by the magnetic part,
The magnetic part is slidably disposed on the outer periphery of the cylindrical part in the central axis direction of the fixed part,
The length of the magnetic part in the central axis direction of the cylindrical part is longer than the position of the end part on the anode end side of the rotating anode of the large diameter part of the rotor, and when the magnetic part is slid to the target side, the hole The length must not be blocked
X-ray tube device characterized by the above . Disk-shaped target as the X-ray source, a rotor and a connection portion for coupling the large diameter portion and both the high conductivity in the small-diameter portion and a cylindrical supporting the target, the rotor at a connection of the rotor rotary shaft supporting bearing for rotatably supporting the rotary shaft, a fixed portion for supporting the bearing has a cylindrical portion at the inner circumferential side of the cylindrical portion, and the large diameter portion of said rotor and said stationary portion A rotating anode having a magnetic part made of a ferromagnetic material disposed between the cylindrical part, a cathode for emitting an electron current for forming a focal point serving as an X-ray source on the target of the rotating anode, A rotating anode X-ray tube having an envelope that insulates and supports the rotating anode and the cathode and is hermetically sealed in a vacuum-tight manner is immersed in an X-ray tube and an electric shock structure X-ray tube container with insulating oil. an X-ray tube device for housing, the cylindrical portion of the fixed portion of the rotary anode A hole provided in the surface and penetrating into the inside of the cylindrical portion, the hole positioned from the end of the large-diameter portion of the rotor to the anode end of the rotating anode, and a lid that covers the hole in an openable and closable manner Means for producing the rotating anode in an X-ray tube device comprising:
After attaching a lubricant to the bearing, assembling the rotary anode and closing the hole with the lid means ;
Performing a break-in rotation of the rotating anode ;
Impacting the rotating anode while holding the rotating anode in a vertical position with the target on top ;
A removal step of opening the hole by the lid means and removing the dropped lubricant;
And reclosing the hole with the lid means . A method of manufacturing a rotating anode, comprising: A method for producing a rotating anode according to claim 6,
In the removing step, further confirming the state of the lubricant falling off.
A method for producing a rotating anode . A method for producing a rotating anode according to claim 6 or 7,
The method further includes a step of measuring the amount of the removed lubricant after the removing step.
A method for producing a rotating anode .

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