Tube core assembly of X-ray tube

Abstract

The invention discloses a tube core assembly of an X-ray tube, which comprises a cathode assembly, an anode assembly, a tube shell, an exhaust lamp filament and an air suction piece, and is characterized in that the cathode assembly comprises a cathode bottom plate and a working lamp filament fixed on the cathode bottom plate, and the working lamp filament is used for emitting first electrons; the anode assembly comprises a rotatable anode target disc, and the anode target disc comprises an annular target surface which receives first electron bombardment and generates X-rays; a vacuum environment is formed in the tube shell, the exhaust lamp filament is fixed to the cathode bottom plate and used for emitting second electrons, in the exhaust stage of the tube core assembly, the annular target surface receives bombardment of the second electrons so as to release gas in the anode target disc, and the gas suction part is used for removing gas in the tube shell. The technical problems that when an existing X-ray tube core exhaust process depends on heating and degassing of a working filament, the filament is damaged and lost due to oxidation reaction and positive ion bombardment due to residual air in the initial exhaust stage, the service life of the filament and an X-ray tube is shortened, and the maintenance cost of medical equipment is increased are solved.

Description

Technical Field

[0001] This invention relates to the field of X-ray tube technology, and particularly to a core assembly for an X-ray tube. Background Technology

[0002] X-ray tubes are mainly used in medical equipment such as X-ray machines and CT scanners. Under the application of external high pressure, they generate X-rays for doctors to diagnose or treat patients.

[0003] As a core component in the field of medical diagnostics, the vacuum level of the X-ray tube's core assembly directly determines its performance and lifespan. During the core assembly manufacturing process, the venting process is a crucial step in creating a high-vacuum environment. It requires removing residual air from the core to prevent energy loss due to collisions between the electron beam and gas molecules during transmission. Simultaneously, it prevents gas ionization from causing discharge phenomena that could damage the cathode filament, thus affecting its lifespan.

[0004] During the venting stage of the X-ray tube assembly, current methods primarily rely on the working filament of the cathode as a heat source. Heating the filament causes it to emit electrons, which bombard the anode, releasing gas from the anode material. Vacuum pumps and other vacuum devices are then used to extract air from the assembly, increasing the vacuum level. However, this approach has the following drawbacks: In the initial venting stage, residual air within the tube is not completely removed, requiring the working filament to operate at high temperatures in a gas-filled environment. The oxygen and other active components in the air react violently with the high-temperature filament. On one hand, oxygen reacts with the tungsten-based material of the filament to form tungsten oxide, resulting in a brittle oxide layer on the filament surface. This layer easily detaches during thermal expansion and contraction, causing uneven wear of the filament diameter. Simultaneously, the residual air ionizes under electron bombardment, generating positive ions that bombard the filament surface, causing material sputtering and further thinning the filament diameter, ultimately significantly shortening its lifespan. As the core consumable component of the X-ray tube, premature filament failure directly impacts the tube's long-term lifespan and increases maintenance costs for medical equipment. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a core assembly for an X-ray tube, which solves the technical problem that when the exhaust process of the existing X-ray tube core relies on heating the working filament for degassing, residual air in the initial exhaust stage causes damage to the filament due to oxidation and positive ion bombardment, thereby shortening the service life of the filament and X-ray tube and increasing the maintenance cost of medical equipment.

[0006] This invention is achieved through the following technical solution:

[0007] An X-ray tube core assembly, comprising:

[0008] A cathode assembly, comprising a cathode base plate and a working filament fixed on the cathode base plate, the working filament being used to emit a first electron;

[0009] An anode assembly, the anode assembly including a rotatable anode target disk, the anode target disk including an annular target surface that receives a first electron bombardment and generates X-rays;

[0010] A housing, the interior of which forms a vacuum environment, and the cathode assembly and the anode assembly are housed within the vacuum environment of the housing;

[0011] An exhaust filament is fixed to the cathode base plate and is used to emit a second electron. During the exhaust phase of the die assembly, the annular target surface receives the second electron bombardment to release the gas in the anode target disk.

[0012] A suction element, used to remove gas from inside the casing.

[0013] Furthermore, the exhaust filament rotates once around the axis of the anode target disk to form a first motion trajectory, and the working filament rotates once around the axis of the anode target disk to form a second motion trajectory. In the axial direction of the anode target disk, the orthographic projection of the first motion trajectory on the anode target disk coincides with the orthographic projection of the second motion trajectory on the anode target disk.

[0014] Along the axial direction of the anode target disk, the orthographic projection of the exhaust filament on the anode target disk and the orthographic projection of the working filament on the anode target disk are staggered and both are located within the annular target surface.

[0015] Furthermore, the working filament and the exhaust filament are arranged symmetrically about the axis of the anode target disk.

[0016] Furthermore, the cathode base plate includes a main body and a pair of support parts fixed in the circumferential direction of the main body, and the working filament and the exhaust filament are respectively fixed on the pair of support parts.

[0017] Furthermore, the support portion is integrally formed with the main body portion.

[0018] Furthermore, the exhaust filament and the working filament are respectively disposed on the side of the support facing the anode target disk, and the working filament and the exhaust filament are located on the same horizontal plane.

[0019] Furthermore, the cathode assembly also includes a cathode housing connected to the cathode end of the tube shell, and a first core post is disposed inside the cathode housing. The first core post is connected to the working filament and the exhaust filament respectively.

[0020] Furthermore, the intake component includes a first degassing agent, which is connected to the first core post;

[0021] The intake component also includes a vacuum pumping device, which is connected to the exhaust pipe on the tube shell during the exhaust phase of the core assembly.

[0022] Furthermore, the cathode end of the tube shell is also provided with a heating wire, a second core post and a cover plate. The side wall of the tube shell protrudes outward to form an installation cylinder. The cover plate is sealed and fixed at the opening of the installation cylinder. The second core post passes through the cover plate and is fixedly connected to the cover plate. The second core post is externally connected to a DC power supply. The heating wire is located inside the tube shell and is connected to the second core post. The suction component also includes a second degassing agent connected to the second core post.

[0023] Furthermore, the X-ray tube includes a housing covering the outside of the core assembly, and a conductive terminal connected to the second core post is mounted on the housing. The conductive terminal is used to electrically connect to the DC power supply.

[0024] Compared with the prior art, the advantages of this invention are:

[0025] 1. By adding an exhaust filament, the working filament does not work during the exhaust phase of the core assembly. Instead, the second electron generated by the exhaust filament bombards the annular target surface, which fully releases the gas adsorbed in the anode target disk. The released gas is then removed by the gas intake component, which significantly improves the vacuum level inside the tube shell. This avoids material loss and structural deformation of the working filament due to high-temperature bombardment during the exhaust process, and effectively extends its service life.

[0026] 2. By optimizing the positions of the exhaust filament and the working filament, the projections of both filaments are confined within the annular target surface. This ensures that the bombardment areas of the first and second electrons are consistent, guaranteeing that the annular target surface is directly bombarded by the second electrons during the exhaust phase. This results in the highest temperature at the annular target surface, effectively promoting the full release of gas from the anode material at the annular target surface. Furthermore, the exhaust filament completely simulates the electron emission path and bombardment position of the working filament, ensuring that the heat distribution of the annular target surface during exhaust is highly consistent with the X-ray generation area under normal operating conditions. This ensures that the exhaust effect matches the actual operating conditions, improving the stability and reliability of the die assembly in subsequent use. Attached Figure Description

[0027] Figure 1 Cross-section of the die assembly Figure 1 ;

[0028] Figure 2 This is a partial cross-sectional view of the die assembly;

[0029] Figure 3 This is a schematic diagram of the cathode base plate.

[0030] Figure 4 Cross-section of the die assembly Figure 1 ;

[0031] Figure 5 This is a cross-sectional view of an X-ray tube.

[0032] 100. Cathode assembly; 110. Cathode base plate; 111. Main body; 112. Support; 120. Working filament; 130. Cathode housing; 140. First core post; 200. Anode assembly; 210. Anode target plate; 211. Annular target surface; 300. Tube shell; 310. Exhaust pipe; 320. Mounting cylinder; 400. Exhaust filament; 500. Heating wire; 510. First degassing agent; 520. Second degassing agent; 600. Outer shell; 610. Conductive terminal; 700. Second core post; 800. Cover plate. Detailed Implementation

[0033] The following detailed, non-limiting description of the invention's technical solutions, in conjunction with preferred embodiments and accompanying drawings, is provided. In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention.

[0034] like Figure 1 and Figure 2As shown, an embodiment of the present invention provides a core assembly for an X-ray tube, comprising a cathode assembly 100, an anode assembly 200, a tube shell 300, an exhaust filament 400, and a suction device. The cathode assembly 100 includes a cathode base plate 110 and a working filament 120 fixed on the cathode base plate 110, the working filament 120 being used to emit a first electron. The anode assembly 200 includes a rotatable anode target disk 210, the anode target disk 210 including an annular target surface 211 for receiving the first electron bombardment and generating X-rays. A vacuum environment is formed inside the tube shell 300, and the cathode assembly 100 and the anode assembly 200 are housed within the vacuum environment of the tube shell 300. The exhaust filament 400 is fixed on the cathode base plate 110 and is used to emit a second electron. During the exhaust phase of the core assembly, the annular target surface 211 receives the second electron bombardment to release the gas in the anode target disk 210. The suction device is used to remove the gas inside the tube shell 300. During the venting phase of the die assembly, the working filament 120 is not activated, while the venting filament 400 is heated and emits a second electron. This second electron bombards the annular target surface 211 of the anode target disk 210, causing the gas adsorbed inside the anode material to be released by heat. Subsequently, the residual gas inside the casing 300 is removed by the adsorption of the suction component, increasing the vacuum level and preventing damage to the working filament 120 caused by the high temperature during the venting phase. This extends the service life of the die assembly and reduces the maintenance cost of medical equipment. Simultaneously, the second electron generated by the venting filament 400 and the first electron generated by the working filament 120 both bombard the same annular target surface 211, resulting in more uniform and thorough venting of the annular target surface 211. This effectively prevents residual gas from remaining, improving the vacuum stability of the die assembly and the reliability of its subsequent operation.

[0035] Specifically, the exhaust filament 400 rotates once around the axis X of the anode target disk 210 to form a first motion trajectory, and the working filament 120 rotates once around the axis X of the anode target disk 210 to form a second motion trajectory. In the axial direction of the anode target disk 210, the orthographic projection of the first motion trajectory on the anode target disk 210 coincides with the orthographic projection of the second motion trajectory on the anode target disk 210. Furthermore, in the axial direction of the anode target disk 210, the orthographic projection of the exhaust filament 400 on the anode target disk 210 and the orthographic projection of the working filament 120 on the anode target disk 210 are staggered and both located within the annular target surface 211. The working filament 120 and the exhaust filament 400 are spatially independent, avoiding thermal stress damage to the working filament caused by high-temperature radiation during the exhaust phase. Furthermore, the projections of both filaments are confined within the annular target surface 211, ensuring that the bombardment areas of the first and second electrons are consistent. This guarantees that the annular target surface 211 is directly bombarded by the second electron during the exhaust phase, resulting in the highest temperature at the annular target surface 211 and effectively promoting the full release of gas from the anode material at the annular target surface 211. It can be understood that the exhaust filament 400 completely simulates the electron emission path and bombardment position of the working filament 120, ensuring that the heat distribution of the annular target surface 211 during the exhaust process is highly consistent with the X-ray generation area under normal operating conditions. This ensures that the exhaust effect matches the actual operating conditions, improving the stability and reliability of the die assembly in subsequent use.

[0036] In this embodiment, the working filament 120 and the exhaust filament 400 are symmetrically arranged about the X-axis of the anode target disk 210. At this time, the working filament 120 and the exhaust filament 400 are at their farthest distance, and the thermal interference between them is minimized. This effectively avoids the cumulative effect of heat radiation from the exhaust filament to the working filament when it is operating at high temperature, and further ensures the structural stability and material properties of the working filament during the non-working phase.

[0037] like Figure 3 As shown, the cathode base plate 110 includes a main body 111 and a pair of support portions 112 fixed in the circumferential direction of the main body 111. The support portions 112 are integrally formed with the main body 111. The working filament 120 and the exhaust filament 400 are respectively fixed on the pair of support portions 112. The exhaust filament 400 and the working filament 120 are respectively arranged on the side of the support portion 112 facing the anode target disk 210, and the working filament 120 and the exhaust filament 400 are located on the same horizontal plane. By setting the working filament 120 and the exhaust filament 400 on the same horizontal plane, the electron beam bombardment position is avoided due to height differences. The two filaments are symmetrically arranged in the same plane, which not only simplifies the assembly process, but also further enhances the consistency between the operating conditions of the exhaust filament 400 in the exhaust stage and the operating conditions of the working filament 120 in the actual working stage, effectively extending the device life and improving the overall stability.

[0038] The cathode assembly 100 also includes a cathode housing 130 connected to the cathode end of the tube housing 300. A first core post 140 is disposed inside the cathode housing 130, and the first core post 140 is connected to both the working filament 120 and the exhaust filament 400. The cathode housing 130 can be made of ceramic or glass and is fixed to the cathode end of the tube housing 300 by brazing. The first core post 140 is fixed to the cathode housing 130 by brazing.

[0039] The intake component also includes a vacuum pumping device. During the exhaust phase of the core assembly, the vacuum pumping device is connected to the exhaust pipe 310 on the housing 300. After exhaust is complete, i.e., when the vacuum level in the vacuum chamber reaches the working requirements, the user cuts the exhaust pipe 310 with a cutting tool, disconnecting the exhaust pipe 310 from the vacuum pumping device. The cut point of the vacuum pumping device self-seales after being cut by the cutting tool. A hydraulic shearing tool is used. The exhaust pipe 310 can be made of copper, nickel, iron, or their alloys.

[0040] The intake component includes a first getter 510, which is connected to the first core post 140. The first getter 510 can be activated during the exhaust and operation phases of the core assembly, and its surface is made highly active by high temperature, thereby absorbing residual gas molecules and further improving and maintaining the vacuum inside the core.

[0041] like Figure 4 As shown, the cathode end of the housing 300 is also provided with a heating wire 500, a second core 700, and a cover plate 800. A mounting cylinder 320 protrudes outward from the side wall of the housing 300. The cover plate 800 is sealed and fixed to the opening of the mounting cylinder 320. The second core 700 passes through and is fixedly connected to the cover plate 800, and is externally connected to a DC power supply. The heating wire 500 is located inside the housing 300 and connected to the second core 700. The suction component also includes a second getter 520 connected to the second core 700. By providing an additional second getter 520, the adsorption capacity for gases inside the housing 300 can be further enhanced, especially in maintaining the stability of the vacuum environment after long-term device operation.

[0042] In this embodiment, the shell 300 can be made of metal, ceramic or glass. In this embodiment, the shell 300 is preferably made of metal. The cover plate 800 is made of ceramic or glass and is sealed and fixed to the opening of the mounting cylinder 320 by brazing. The second core post 700 is fixed to the cover plate 800 by brazing.

[0043] like Figure 5As shown, the X-ray tube includes a housing 600 covering the outside of the core assembly. A conductive terminal 610 connected to the second core 700 is mounted on the housing 600, and the conductive terminal 610 is used for electrical connection to a DC power supply. Since the first getter 510 requires activation by the working filament 120, the heat generated when current is applied to the working filament 120 is conducted to the first getter 510, causing it to reach its activation temperature and perform its gas-absorbing function. However, when the X-ray tube is not in operation or running at low power, the working filament 120 generates insufficient heat, resulting in the first getter 510 failing to activate effectively and a decrease in vacuum maintenance capability. The second getter 520, on the other hand, is activated by a heating wire 500, which is independently powered by a DC power supply outside the housing 600. Therefore, it can be independently started during X-ray tube shutdown or low-load periods, ensuring that the heating wire 500 continuously receives a stable current, thereby maintaining the active state of the second getter 520 and continuously adsorbing trace amounts of gas within the tube housing 300 to maintain vacuum. The synergistic working mechanism of the two degassing agents significantly improves the stability and reliability of vacuum devices under different operating conditions.

[0044] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A core assembly for an X-ray tube, characterized in that, include: A cathode assembly (100) includes a cathode base plate (110) and a working filament (120) fixed on the cathode base plate (110), the working filament (120) being used to emit a first electron; An anode assembly (200) includes a rotatable anode target disk (210) including an annular target surface (211) that receives a first electron bombardment and generates X-rays. A housing (300) is provided, and a vacuum environment is formed inside the housing (300). The cathode assembly (100) and the anode assembly (200) are housed within the vacuum environment of the housing (300). An exhaust filament (400) is fixed on the cathode base plate (110) and is used to emit a second electron. During the exhaust phase of the die assembly, the annular target surface (211) receives the second electron bombardment to release the gas in the anode target disk (210). A suction element for removing gas from inside the housing (300).

2. The core assembly of the X-ray tube according to claim 1, characterized in that, The exhaust filament (400) rotates once around the axis (X) of the anode target disk (210) to form a first motion trajectory, and the working filament (120) rotates once around the axis (X) of the anode target disk (210) to form a second motion trajectory. In the axial direction of the anode target disk (210), the orthographic projection of the first motion trajectory on the anode target disk (210) coincides with the orthographic projection of the second motion trajectory on the anode target disk (210). In the axial direction of the anode target disk (210), the orthographic projection of the exhaust filament (400) on the anode target disk (210) and the orthographic projection of the working filament (120) on the anode target disk (210) are staggered and both are located within the annular target surface (211).

3. The core assembly of the X-ray tube according to claim 2, characterized in that, The working filament (120) and the exhaust filament (400) are arranged symmetrically about the axis (X) of the anode target disk (210).

4. The core assembly of the X-ray tube according to claim 2, characterized in that, The cathode base plate (110) includes a main body (111) and a pair of support parts (112) fixed in the circumferential direction of the main body (111). The working filament (120) and the exhaust filament (400) are respectively fixed on the pair of support parts (112).

5. The core assembly of the X-ray tube according to claim 4, characterized in that, The support part (112) is integrally formed with the main body part (111).

6. The core assembly of the X-ray tube according to claim 4, characterized in that, The exhaust filament (400) and the working filament (120) are respectively disposed on the side of the support (112) facing the anode target disk (210), and the working filament (120) and the exhaust filament (400) are located on the same horizontal plane.

7. The core assembly of the X-ray tube according to claim 2, characterized in that, The cathode assembly (100) further includes a cathode housing (130) connected to the cathode end of the tube housing (300), and a first core post (140) is provided inside the cathode housing (130). The first core post (140) is connected to the working filament (120) and the exhaust filament (400) respectively.

8. The core assembly of the X-ray tube according to claim 7, characterized in that, The intake component includes a first degassing agent (510), which is connected to the first core post (140).

9. The core assembly of the X-ray tube according to claim 8, characterized in that, The cathode end of the tube shell (300) is also provided with a heating wire (500), a second core column (700) and a cover plate (800). The side wall of the tube shell (300) protrudes outward to form an installation cylinder (320). The cover plate (800) is sealed and fixed at the opening of the installation cylinder (320). The second core column (700) passes through the cover plate (800) and is fixedly connected to the cover plate (800). The second core column (700) is connected to an external DC power supply. The heating wire (500) is located inside the tube shell (300) and is connected to the second core column (700). The suction component also includes a second degassing agent (520) connected to the second core column (700).

10. The core assembly of the X-ray tube according to claim 9, characterized in that, The X-ray tube includes a housing (600) covering the outside of the core assembly, and a conductive terminal (610) connected to the second core column (700) is mounted on the housing (600). The conductive terminal (610) is used to electrically connect to the DC power supply.

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