Welding device and welding method for rotating anode of X-ray tube

Abstract

The invention discloses a welding device and method for a rotating anode of an X-ray tube, and the welding device comprises a housing which is used for providing a vacuum environment and is internally provided with a containing cavity; the annular electron beam generator is located in the containing cavity and used for generating an annular electron beam, the annular electron beam can form an annular melting area on the rotating anode to be welded, and a target disc and a rotor of the rotating anode are welded into a whole; and the power supply system is respectively connected with the annular electron beam generator and the rotating anode to form an electric field, so that the annular electron beam is accelerated to move towards the rotating anode. According to the welding device, the annular electron beam generator generates the annular electron beam matched with the outline of the thread to be welded, and energy of the annular electron beam can uniformly act on the whole circumference of the thread connection, so that melting and re-solidification of the whole thread connection area can be completed at a time in the welding process; and a continuous and uniform welding seam is formed.

Description

Technical Field

[0001] This invention relates to the field of X-ray tubes. More specifically, it relates to a welding apparatus and welding method for an X-ray tube target disk. Background Technology

[0002] An X-ray tube consists of a vacuum tube and a cathode filament and a rotating anode housed within it. The cathode filament generates an electron beam directed at the rotating anode, whose surface converts the kinetic energy of the electron beam into high-frequency electromagnetic waves, i.e., X-rays. The rotating anode typically includes a target disk (such as a metal substrate) and a rotor. The target disk and rotor are fixedly connected and rotatably connected to a base. The target disk generates X-rays when bombarded by electrons from the cathode filament, and the base serves for heat dissipation. The rotating anode is a crucial component of the X-ray tube. During operation, the target disk needs to rotate at high speed in a high-temperature environment to dissipate heat; therefore, ensuring the reliability of the connection between the target disk and the rotor is essential. Summary of the Invention

[0003] The purpose of this invention is to provide a welding apparatus and method for a rotating anode of an X-ray tube. By using this welding apparatus to weld the target plate and the rotor, the reliability of the connection between the two can be improved.

[0004] According to one aspect of the present invention, a welding apparatus for a rotating anode of an X-ray tube is provided, comprising: a housing for providing a vacuum environment, wherein a receiving cavity is formed inside the housing; A ring electron beam generator, located within the receiving cavity, is used to generate a ring electron beam that can form a ring-shaped molten zone on the rotating anode to be welded, thereby welding the target disk and rotor of the rotating anode into one piece. The power supply system is connected to the annular electron beam generator and the rotating anode respectively to form an electric field, so as to accelerate the annular electron beam toward the rotating anode.

[0005] Optionally, the annular electron beam generator includes a core column, a cathode shield, and an annular filament. The core column is provided with a sealing structure for sealing connection with the housing. The cathode shield is disposed at the end of the core column near the center of the receiving cavity. The annular filament is connected to the cathode shield through two electrodes, and the two electrodes are respectively connected to the power supply system.

[0006] Optionally, the annular filament has two leads, which are respectively connected to the two electrodes and are located at both ends of the annular diameter.

[0007] Optionally, one of the two electrodes is electrically connected to the cathode shield, while the other is insulated from the cathode shield, and the voltage values ​​on the two electrodes are not equal.

[0008] Optionally, the annular filament is generally in the form of a circular annular sheet structure, with the filament arranged in a serpentine bend to form a circular shape.

[0009] Optionally, the cathode shield has a circular boss at its center and an annular protrusion near the edge of the cathode shield. The circular boss is located inside the annular filament, and the annular protrusion is located outside the annular filament.

[0010] Optionally, a focusing coil is provided near the edge of the cathode shield, and the annular filament is located inside the focusing coil. The focusing coil is used to form an electromagnetic field that focuses the annular electron beam.

[0011] Optionally, the welding apparatus further includes a heating device located on the outside of the housing, or the heating device located on the inside of the housing.

[0012] According to another aspect of the present invention, a welding method for a rotating anode of an X-ray tube is provided, comprising the steps of: The target disk and rotor of the rotating anode are connected by threads; The rotating anode is placed inside the housing of the welding device and connected to the positive terminal of the power supply system. The cavity containing the outer shell is evacuated; The annular electron beam generator is turned on to generate the annular electron beam, so that the annular electron beam forms an annular molten zone on the rotating anode to be welded, thereby welding the target disk and the rotor into one piece.

[0013] Optionally, it also includes: After the target disk and rotor of the rotating anode are connected by threads, an annular welding groove is formed at the threaded connection, and an annular solder is placed in the welding groove.

[0014] The beneficial effects of this invention are as follows: The welding apparatus of this invention generates an annular electron beam that matches the profile of the thread to be welded using an annular electron beam generator. The energy of this annular electron beam is uniformly applied to the entire circumference of the threaded connection, enabling the welding process to complete the melting and resolidification of the entire threaded connection area in one pass, forming a continuous and uniform weld. This annular electron beam generator can concentrate the release of high-energy electrons within a specific annular region, achieving the effect of "circumferential overall welding," thereby avoiding the stress concentration and uneven welding problems that may occur with traditional multi-point welding. Attached Figure Description

[0015] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0016] Figure 1 A cross-sectional view of the welding apparatus of the present invention is shown.

[0017] Figure 2 A schematic diagram of the structure of the annular electron beam emitter of the present invention is shown.

[0018] Figure 3 A schematic diagram of the cathode shield of the present invention is shown.

[0019] Figure 4 The diagram shows the structure of the cathode shield and the annular filament of the present invention.

[0020] Figure 5 A schematic diagram of the annular filament of the present invention is shown.

[0021] Figure 6 A schematic diagram of another embodiment of the welding apparatus of the present invention is shown. Detailed Implementation

[0022] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments and accompanying drawings, further explains the invention. Similar components in the drawings are indicated by the same reference numerals. Those skilled in the art should understand that the specific description below is illustrative rather than restrictive and should not be construed as limiting the scope of protection of the present invention.

[0023] In the description of this invention, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0024] It should be noted that although the terms "first," "second," etc., may be used herein to describe various components, members, elements, regions, layers, and / or portions, these components, members, elements, regions, layers, and / or portions should not be limited by these terms. Rather, these terms are used to distinguish one component, member, element, region, layer, and / or portion from another. Thus, for example, the first component, first member, first element, first region, first layer, and / or first portion discussed below may be referred to as a second component, second member, second element, second region, second layer, and / or second portion without departing from the teachings of the invention.

[0025] It should also be noted that in the description of this invention, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0026] As an essential component of X-ray generators, the anode target can be divided into fixed and rotating types depending on its structure and operating environment. A fixed anode consists of a target material and an anode body. When a focused electron beam generated by the cathode irradiates a point on the anode, X-rays are produced, along with significant heat. It is typically a consumable part that requires periodic replacement. In contrast, a rotating anode target mainly consists of an anode target and a rotor. When the electron beam irradiates the anode target material, the continuously rotating anode effectively prevents itself from being burned by the electron beam and continuously provides a new irradiated target surface. This not only increases the utilization rate of the anode target material and the heat dissipation area of ​​the target surface but also significantly improves the power of the X-ray tube, allowing for uninterrupted long-term use.

[0027] As a key component in X-ray generation, the structural stability and reliability of the rotating anode directly affect the performance and lifespan of the entire equipment. The rotating anode generates X-rays under high-energy electron beam bombardment, but its energy conversion efficiency is extremely low; only about 1% of the energy is converted into X-ray energy, while the remaining 99% is converted into heat, resulting in local temperatures reaching as high as 2600℃. Therefore, the rotating anode needs to possess characteristics such as high high-temperature strength, good thermal shock resistance, and rapid heat dissipation. The target disk is typically made of high-melting-point metals such as tungsten or molybdenum, or their alloys, and is quite heavy, requiring threaded fastening to the rotor. The target disk has a threaded hole in its center, and one end of the rotor is threaded; the two are connected as a single unit through the thread. Alternatively, the target disk has a through hole in its center, and one end of the rotor is threaded; the end of the rotor passes through the central hole of the target disk and connects to a nut, thus connecting the target disk and rotor as a single unit. Because the rotating anode in an X-ray tube needs to rotate continuously at extremely high speeds (for example, up to 10,000 rpm in some X-ray tubes) while enduring the high temperatures and thermal stresses generated by electron beam bombardment, the connection between the target disk and the rotor must possess extremely high mechanical strength and fatigue resistance. In related technologies, laser spot welding is performed on the threaded connections after the initial thread connection to increase the connection strength. However, since the welding pads and rotor are mostly made of refractory metals, the molten area of ​​the laser spot weld is small and insufficient to increase strength. Furthermore, it is prone to failure during the frequent start-stop cycles and continuous thermal shock of the rotating anode.

[0028] Based on this, embodiments of this disclosure provide a welding apparatus for welding the target disk and rotor of an X-ray tube rotating anode. For example... Figures 1-6 As shown, the welding apparatus of this disclosure includes a housing 10, an annular electron beam generator 20, and a power supply system 30. A receiving cavity is formed inside the housing 10, and both the annular electron beam generator 20 and the rotating anode 100 to be welded are located within the receiving cavity. The housing 10 provides a vacuum environment during welding. The annular electron beam generator 20 generates an annular electron beam that forms an annular molten zone on the rotating anode 100, thereby welding the target disk 101 and rotor 102 of the rotating anode together. It is understood that the annular electron beam should cover the threaded connection between the target disk 101 and the rotor 102, and the annular electron beam should completely cover the threaded connection in the circumferential direction.

[0029] In this disclosure, a ring-shaped electron beam generator is configured to produce a ring-shaped electron beam that matches the profile of the thread to be welded. The energy of this ring-shaped electron beam is uniformly applied across the entire circumference of the threaded connection, rather than being limited to a few discrete points. This design allows the welding process to complete the melting and resolidification of the entire threaded connection area in a single operation, forming a continuous and uniform weld. Unlike traditional point-based electron beams, this ring-shaped electron beam generator can concentrate the release of high-energy electrons within a specific ring-shaped region, achieving a "circumferential overall welding" effect, thereby avoiding the stress concentration and uneven welding problems that may occur with traditional multi-point welding.

[0030] Furthermore, the welding apparatus of this disclosure requires no relative movement between itself and the rotating anode 100 to be welded. In traditional welding processes, to achieve complete coverage of the circumferential weld, the workpiece typically needs to rotate or the welding head needs to move around the workpiece. This relative movement places high demands on the motion control precision, synchronization, and mechanical complexity of the equipment. For example, in automated industries, to achieve electron beam welding of circular welds, a precision rotary table and a multi-axis linkage control system are required. However, this invention uses an electron beam generator capable of producing an annular focal point, where the electron beam itself covers the entire area required for welding. Therefore, by simply positioning the welding apparatus in the correct position and activating the electron beam, the welding of the entire circumferential thread can be completed in one go. This "static" welding method greatly simplifies the mechanical structure of the welding equipment, reduces dependence on the motion control system, thereby reducing equipment costs, improving the stability and reliability of the welding process, and shortening the production cycle.

[0031] The power supply system 30 is connected to the ring electron beam generator 20 and the rotating anode 100 to form an electric field, thereby accelerating the ring electron beam toward the rotating anode. The cathode of the power supply system 30 is connected to the ring electron beam generator 20, and the positive electrode is connected to the rotating anode 100. For example, the voltage on the ring electron beam generator 20 is -5000 volts, and the voltage on the rotating anode 100 is +5000 volts. The accelerating electrode typically applies a DC high voltage of tens of kilovolts or even higher between the anode and cathode, providing a strong accelerating electric field for the electrons to obtain sufficient energy to melt the metal.

[0032] like Figures 2-4As shown, in this embodiment, the annular electron beam generator 20 includes a core column 21, a cathode shield 22, and an annular filament 23. The core column 21 is a hollow cylindrical structure with a sealing structure 211 for sealing connection with the outer casing 10. The core column 21 can be made of an insulating material, such as ceramic. The cathode shield 22 is located at the end of the core column 21 near the center of the receiving cavity, that is, at the end of the core column 21 near the rotating anode 100. The annular filament 23 is connected to the cathode shield 22 via two electrodes 221, which are respectively connected to the power supply system 30, so that the annular filament 23 can generate an annular electron beam.

[0033] As the source of electron emission, the shape of the annular filament 23 directly determines the form of the electron beam. When the annular filament 23 is heated to a sufficiently high temperature, its surface emits a large number of electrons. When the filament is configured as a closed annular structure, these emitted electrons, under the influence of the electric field, form a preliminary electron cloud with an annular cross-section. Under the influence of the electric field, the electron cloud accelerates towards the rotating anode 100, thus forming an annular electron beam, which in turn forms an annular molten zone on the rotating anode 100. The material of the annular filament 23 is selected from materials with high melting points and strong electron emission capabilities, such as tungsten or tungsten alloys doped with thorium and rhenium, to ensure stability and long lifespan at high temperatures.

[0034] The annular filament 23 generates an annular electron cloud, which gains extremely high kinetic energy under the action of an accelerating electric field, forming a highly concentrated annular region on the workpiece surface, thus creating an annular molten pool with extremely high energy density. The annular electron beam can simultaneously act on the entire circumference of the thread, causing the metal material at the joint to melt in a very short time and rapidly cool and solidify after the electron beam stops bombarding, forming a complete and dense weld. This circumferential simultaneous welding method, compared with traditional point-by-point welding, can more effectively eliminate welding stress, improve the fatigue strength of the weld joint, and ensure the long-term stable operation of the target disk 101 under high-speed rotation and alternating heat loads.

[0035] like Figure 5 As shown, the annular filament 23 has two leads 231, which are respectively connected to the electrode 221, and the two leads 231 are located at the two ends of the diameter of the annulus. Thus, the annular filament 23 is divided into two parallel circuits of half-rings, and the resistance values ​​of the two parallel circuits are equal or have a very small difference, so that the annular filament 23 generates a uniform number of electrons.

[0036] In this embodiment, the annular filament 23 is generally a thin, circular sheet structure, with the filament arranged in a serpentine bend to form a ring. In actual manufacturing, the thin tungsten alloy sheet can be stamped to form a fully serpentine arrangement. This structure can reduce the cross-sectional area of ​​the annular filament 23, increase its resistance, and improve its heating efficiency.

[0037] One of the two electrodes 221 of the cathode shield 22 is electrically connected to the cathode shield 22, while the other electrode 221 is insulated from the cathode shield 22, and the voltage values ​​on the two electrodes 221 are not equal. For example, the voltage value on one electrode 221 is -5000 volts, and the voltage value on the other electrode 221 is -5005 volts. Since the two electrodes 221 are respectively connected to the two leads 231 of the annular filament 23, the voltage difference between the two electrodes 221 can generate a current in the annular filament 23, thereby enabling the annular filament 23 to emit electrons. Furthermore, since one of the electrodes 221 is electrically connected to the cathode shield 22, the cathode shield 22 also carries a negative high voltage, and an accelerating electric field can be formed between the cathode shield 22 and the rotating anode 100, which has a positive high voltage.

[0038] In this embodiment, a circular boss 222 is provided at the center of the cathode shield 22, and an annular protrusion 223 is provided near the edge of the cathode shield 22. The circular boss 222 is located inside the annular filament 23, and the annular protrusion 223 is located outside the annular filament 23. The annular electron beam can be focused by the circular boss 222 and the annular protrusion 223. For example, by precisely designing the external dimensions of the circular boss 222 and the annular protrusion 223, the distance between them, and the negative high voltage applied to them, a focusing electric field can be formed in the annular gap region formed between them, thereby adjusting the annular focal point formed by the annular electron beam on the surface of the workpiece so that it can accurately cover the welding area.

[0039] Furthermore, a coil is provided inside the outer casing 10, which is positioned between the annular filament 23 and the rotating anode 100, and is coaxially arranged with the annular filament 23. The coil generates a focusing electromagnetic field, which deflects the electron beam towards the central axis, thereby achieving focusing of the electron beam. The focusing electromagnetic field and the aforementioned focusing electric field work together to refract the diverging electron beam towards a common annular focal region, ultimately forming a high-quality annular focal point.

[0040] In one example, a focusing coil is located near the edge of the cathode shield 22, extending toward the rotating anode 100, with an annular filament 23 located inside the focusing coil. The focusing coil is used to generate a focusing electromagnetic field that enables the annular electron beam to be focused, thereby adjusting the annular focal point formed by the annular electron beam on the workpiece surface so that it can precisely cover the welding area.

[0041] like Figure 6 As shown, the welding apparatus provided in this disclosure also includes a heating device 40, which is disposed on the outside of the housing 10. For example, the heating device 40 can be a heating coil, which heats the rotating anode 100 with a high-frequency current, thereby preheating the rotating anode 100 before welding.

[0042] The heating device 40 can also be located inside the housing 10. For example, the heating device 40 can be a heating wire or a heating film, which is attached to the inner surface of the housing 10 to heat the rotating anode 100, thereby preheating the rotating anode 100 before welding.

[0043] This disclosure also provides a welding method for a rotating anode of an X-ray tube. In the manufacturing of the X-ray tube, the target disk 101, as the core component that withstands electron bombardment and generates X-rays, needs to be reliably fixed to the high-speed rotating rotor 102. Threaded connections are widely used due to their simple structure and convenient assembly / disassembly. However, relying solely on the mechanical locking force of the threaded connection may lead to loosening under the long-term high-speed rotation and frequent start-stop conditions of the X-ray tube, causing the target disk to become eccentric or even fall off, seriously affecting the normal operation and safety of the equipment. Therefore, this method aims to permanently reinforce the threaded connection to improve its connection strength and reliability, ensuring the long-term stable operation of the X-ray tube under extreme working conditions.

[0044] The welding method disclosed herein includes the following steps: S1. Connect the target disk 101 and rotor 102 of the rotating anode via threads; align the internal thread of the center hole of the target disk 101 with the external thread of the shaft end of the rotor 102, and then tighten it to the predetermined torque. During tightening, it is necessary to ensure the accuracy and cleanliness of the thread fit to avoid impurities or damage affecting the tightness of the connection. The purpose of this step is to establish a preliminary, detachable mechanical connection, providing a stable foundation for subsequent welding reinforcement. The quality of the threaded connection directly affects the performance of the final welded joint, therefore, its assembly process needs to be strictly controlled.

[0045] S2. Place the rotating anode 100 inside the housing 10 of the welding apparatus and connect the rotating anode 100 to the positive terminal of the power supply system 30. Place the pre-assembled target disk 101 and rotor 102 in the vacuum chamber of the electron beam welding apparatus and position them precisely so that the annular focus of the electron beam can accurately cover the root of the threaded connection.

[0046] S3. Evacuate the housing cavity of the outer shell; before welding begins, the system can automatically control the vacuum pump to evacuate the welding chamber to the required high vacuum level (e.g., less than 1×10⁻⁶). -4 Pa) to prevent the electron beam from scattering due to collisions with gas molecules during transmission.

[0047] S4. Turn on the annular electron beam generator 20 to generate the annular electron beam, so that the annular electron beam forms an annular molten zone on the rotating anode 100 to be welded, and welds the target disk 101 and the rotor 102 into one piece.

[0048] After the annular electron beam generator 20 is activated, the high-energy electron beam simultaneously melts the threaded joints along the entire circumference within a very short time, forming a continuous and uniform weld. This weld firmly bonds the target disk and rotor together, with a strength far exceeding that of discrete spot welding. This welding apparatus possesses the ability to flexibly adjust the electron beam energy, which is crucial for achieving high-quality welding. The electron beam energy is primarily determined by the accelerating voltage and beam current. The power supply system 30 of this apparatus can provide a stable and adjustable accelerating voltage, ranging from several kilovolts to over one hundred kilovolts, to meet the welding requirements of metals with different melting points. Simultaneously, the beam current can also be precisely adjusted over a wide range (e.g., from 0.1 mA to 50 mA). By changing the accelerating voltage and beam current, the power density of the electron beam can be precisely controlled, thereby controlling the depth and width of the molten pool. For example, when a deeper weld penetration is required, the accelerating voltage or beam current can be increased; while when a reduction in the heat-affected zone is needed, the electron beam energy should be decreased. This flexible adjustment capability allows the apparatus to adapt to various welding scenarios and optimize welding results.

[0049] This welding method allows for the welding of the rotating anode 100 in a single, circumferential process, eliminating the need for relative movement between the welding head and the workpiece. Thanks to the electron beam welding device capable of generating a ring-shaped focal point, the electron beam's energy can simultaneously cover the entire circumferential welding area. Therefore, during welding, only the relative stationary position of the workpiece and the welding device needs to be maintained; welding can be completed instantaneously by controlling the on and off of the electron beam. This "static" welding implementation significantly simplifies the welding process, avoiding errors that may be introduced by workpiece rotation or welding head movement, such as discontinuous welds and uneven weld depth. Simultaneously, it significantly improves welding efficiency, shortens the processing time for individual workpieces, and facilitates large-scale, automated production.

[0050] In one example, the welding method of this disclosure may further include connecting the target disk 101 and the rotor 102 of the rotating anode by threads, forming an annular welding groove at the threaded connection, and placing an annular solder in the welding groove. The annular solder is then melted by bombarding it with an annular electron beam, fusing it into the welding groove to achieve the welding connection between the target disk 101 and the rotor 102.

[0051] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A welding apparatus for a rotating anode of an X-ray tube, characterized in that, include: A housing for providing a vacuum environment, wherein a receiving cavity is formed inside the housing; A ring electron beam generator, located within the receiving cavity, is used to generate a ring electron beam that can form a ring-shaped molten zone on the rotating anode to be welded, thereby welding the target disk and rotor of the rotating anode into one piece. The power supply system is connected to the annular electron beam generator and the rotating anode respectively to form an electric field, so as to accelerate the annular electron beam toward the rotating anode.

2. The welding apparatus according to claim 1, characterized in that, The annular electron beam generator includes a core column, a cathode shield, and an annular filament. The core column is provided with a sealing structure for sealing connection with the outer shell. The cathode shield is located at the end of the core column near the center of the receiving cavity. The annular filament is connected to the cathode shield through two electrodes, and the two electrodes are respectively connected to the power supply system.

3. The welding apparatus according to claim 2, characterized in that, The annular filament has two leads, which are respectively connected to the two electrodes, and the two leads are located at the two ends of the annular diameter.

4. The welding apparatus according to claim 3, characterized in that, One of the two electrodes is electrically connected to the cathode shield, while the other is insulated from the cathode shield, and the voltage values ​​on the two electrodes are not equal.

5. The welding apparatus according to claim 2, characterized in that, The annular filament is generally in the form of a thin, circular sheet, with the filament arranged in a serpentine, bend pattern to form a ring.

6. The welding apparatus according to claim 2, characterized in that, The cathode shield has a circular boss at its center and an annular protrusion near the edge of the cathode shield. The circular boss is located inside the annular filament, and the annular protrusion is located outside the annular filament.

7. The welding apparatus according to claim 2, characterized in that, A focusing coil is provided near the edge of the cathode shield, and the annular filament is located inside the focusing coil. The focusing coil is used to generate an electromagnetic field that focuses the annular electron beam.

8. The welding apparatus according to claim 1, characterized in that, The welding apparatus further includes a heating device located on the outside of the housing, or the heating device located on the inside of the housing.

9. A welding method for a rotating anode of an X-ray tube, characterized in that, include: The target disk and rotor of the rotating anode are connected by threads; The rotating anode is placed inside the housing of the welding apparatus as described in any one of claims 1 to 8, and the rotating anode is connected to the positive terminal of the power supply system; The cavity containing the outer shell is evacuated; The annular electron beam generator is turned on to generate the annular electron beam, so that the annular electron beam forms an annular molten zone on the rotating anode to be welded, thereby welding the target disk and the rotor into one piece.

10. The welding method according to claim 9, characterized in that, Also includes: After the target disk and rotor of the rotating anode are connected by threads, an annular welding groove is formed at the threaded connection, and an annular solder is placed in the welding groove.

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