Ct tube based on liquid metal bearing and anode assembly and processing method thereof

Abstract

A CT X-ray tube based on a liquid metal bearing, its anode assembly, and a processing method are disclosed. The anode assembly includes an anode target; a rotor; a central shaft portion, including at least a first mating section along its axial direction, the axial direction of which is parallel to a first direction; and an outer shaft portion fitted onto the first mating section. The anode target and rotor are respectively connected to the two ends of the outer shaft portion along the first direction. A filling cavity is formed between the central shaft portion and the outer shaft portion, filled with liquid metal. The anode target rotates with the outer shaft portion about the central shaft portion. The first mating section includes a first section and a second section. The first section is close to the anode target and has multiple first grooves, while the second section has multiple second grooves. The equivalent point of action of the first bearing force generated by the liquid metal film on the outer shaft portion in the first section and the second bearing force generated by the liquid metal film on the outer shaft portion in the second section coincides with the center of gravity of the rotating body formed by the anode target, rotor, and outer shaft portion. This improves the operational stability of the anode assembly.

Description

Technical Field

[0001] This invention relates to the field of X-ray tube technology, and more particularly to a CT tube based on a liquid metal bearing, its anode assembly, and a processing method. Background Technology

[0002] As a core component of medical imaging equipment, the high-speed rotational stability of the anode assembly in a CT tube directly determines the imaging quality and lifespan of the device. Current CT tube anode assemblies generally employ a structure with a central axis and an outer axis. The two ends of the outer axis are connected to the anode target and the drive rotor, respectively. The cavity formed between the central and outer axes is filled with liquid metal, thus forming a liquid metal bearing. The fluidity of the liquid metal enables high-speed rotational support and lubrication of the outer axis relative to the central axis.

[0003] In actual operation, the rotor drives the outer shaft to rotate the anode target at tens of thousands of revolutions per minute to prevent the anode target from accumulating excessive heat due to electron beam bombardment. Because the anode target disk is quite heavy, its center of gravity is usually biased to one side, making it difficult to match with the resultant force of the load-bearing structure, thus causing imbalance. Therefore, it is necessary to maintain a stable rotational posture during operation to ensure electron beam focusing accuracy and avoid image blurring or artifacts. Summary of the Invention

[0004] The technical problem solved by the present invention is to provide an improved anode assembly for a CT tube and a CT tube.

[0005] To address the aforementioned technical problems, this invention provides an anode assembly for a CT tube, comprising: an anode target; a rotor for driving the anode target to rotate; a central shaft portion including at least a first mating section along its axial direction, the axial direction of the central shaft portion being parallel to a first direction; and an outer shaft portion sleeved on the first mating section. The anode target and the rotor are respectively connected to the two ends of the outer shaft portion along the first direction. A filling cavity is formed between the central shaft portion and the outer shaft portion, and the filling cavity is filled with liquid metal. Under the drive of the rotor, the anode target rotates with the outer shaft portion about the central shaft portion. Along the first direction, the first mating section includes a first segment and a second segment, the first segment being closer to the anode target than the second segment. The outer peripheral surface of the first section has multiple first grooves spaced apart, and the outer peripheral surface of the second section has multiple second grooves spaced apart. The first grooves and the second grooves are used to guide the liquid metal to form a liquid metal film with pressure distribution on the surface of the first mating section. The first pattern formed by the multiple first grooves on the outer peripheral surface of the first section is different from the second pattern formed by the multiple second grooves on the outer peripheral surface of the second section, so that the effective point of the resultant force of the first bearing force generated by the liquid metal film on the outer shaft portion by the first section and the second bearing force generated by the liquid metal film on the outer shaft portion by the second section coincides with the center of gravity of the rotating body formed by the anode target, the rotor and the outer shaft portion.

[0006] Optionally, the first pattern and the second pattern are graphically associated so that the first bearing capacity and the second bearing capacity satisfy: F1×L1=F2×L2, where F1 is the first bearing capacity; F2 is the second bearing capacity; L1 is the distance between the equivalent point of application of the first bearing capacity and the equivalent point of application of the resultant force; and L2 is the distance between the equivalent point of application of the second bearing capacity and the equivalent point of application of the resultant force.

[0007] Optionally, the value of the first bearing capacity is greater than the value of the second bearing capacity.

[0008] Optionally, at least one parameter of the first groove and the second groove is different to make the first pattern different from the second pattern, and the parameter includes at least the depth, density, width, and groove width ratio of the groove.

[0009] Optionally, the width-to-slot ratio of the first trench is smaller than that of the second trench.

[0010] Optionally, the width-to-slot ratio of the first trench is between 0.3:1 and 0.9:1.

[0011] Optionally, the width-to-slot ratio of the second trench is between 1:1 and 2:1.

[0012] Optionally, the ratio of the width ratio of the first groove to the width ratio of the second groove is 1:1.2 to 1:3.5.

[0013] Optionally, the depth of the first trench is greater than the depth of the second trench.

[0014] Optionally, the density of the first trench is greater than the density of the second trench.

[0015] Optionally, the width of the first groove is greater than the width of the second groove.

[0016] Optionally, both the first groove and the second groove are herringbone grooves, and the herringbone angle of the first groove is greater than that of the second groove.

[0017] Optionally, the herringbone angle of the first groove is between 75° and 110°.

[0018] Optionally, the herringbone angle of the second groove is between 50° and 80°.

[0019] Optionally, the difference between the herringbone angle of the first groove and the herringbone angle of the second groove is 15°~30°.

[0020] Optionally, the first groove and the second groove are formed by milling, electrical discharge machining, or laser engraving.

[0021] Optionally, the processes for forming the first trench and the second trench are different.

[0022] Optionally, the anode assembly further includes: a cap portion having a central through hole extending along the first direction, the cap portion being sleeved on the central shaft portion and closing the opening of the filling cavity away from the anode target, the cap portion rotating synchronously with the outer shaft portion, and at least one anti-overflow groove being formed on the wall of the cap portion forming the central through hole.

[0023] To address the aforementioned technical problems, this invention also provides a CT tube, including the aforementioned anode assembly.

[0024] To address the aforementioned technical problems, this invention also provides a method for processing an anode assembly for a CT tube, comprising: providing an anode target, a rotor, a central shaft portion, and an outer shaft portion, wherein the central shaft portion includes a first mating section along the axial direction; forming multiple first grooves on the outer peripheral surface of a first section of the first mating section; forming multiple second grooves on the outer peripheral surface of a second section of the first mating section; fitting the outer shaft portion onto the first mating section of the central shaft portion; connecting the anode target and the rotor to both ends of the outer shaft portion respectively; forming a filling cavity between the assembled central shaft portion and the outer shaft portion; and filling the filling cavity with liquid metal; wherein the first pattern formed by the multiple first grooves on the outer peripheral surface of the first section is different from the second pattern formed by the multiple second grooves on the outer peripheral surface of the second section, such that the equivalent point of the resultant force of the first bearing force generated by the liquid metal film on the outer shaft portion by the first section and the second bearing force generated by the liquid metal film on the outer shaft portion by the second section coincides with the center of gravity of the rotating body jointly formed by the anode target, the rotor, and the outer shaft portion.

[0025] Furthermore, the first pattern and the second pattern are graphically correlated so that the first bearing capacity and the second bearing capacity satisfy: F1×L1=F2×L2, where F1 is the first bearing capacity; F2 is the second bearing capacity; L1 is the distance between the equivalent point of action of the first bearing capacity and the equivalent point of action of the resultant force; and L2 is the distance between the equivalent point of action of the second bearing capacity and the equivalent point of action of the resultant force.

[0026] Furthermore, the parameters of the first trench and the second trench were determined through simulation experiments.

[0027] Compared with the prior art, the technical solution of the embodiments of the present invention has the following beneficial effects:

[0028] By employing the technical solution of this application, the first mating section of the central shaft is divided into a first section closer to the anode target and a second section relatively farther away, and the groove patterns of the two sections are different. This allows for targeted adjustment of the magnitude of the first and second bearing forces generated by the liquid metal in the two sections. Furthermore, it ensures that the effective point of application of the resultant force of the bearing forces precisely coincides with the center of gravity of the rotating mass formed by the anode target, rotor, and outer shaft, thereby improving the operational performance and reliability of the liquid metal bearing and enhancing the design flexibility of the CT tube anode structure.

[0029] Furthermore, the matching relationship between the first bearing capacity, the second bearing capacity, and the distance between their corresponding equivalent points of action and the equivalent point of action of the resultant force provides a theoretical basis for the precise control of the equivalent point of action of the resultant force. By modifying this matching relationship, it is possible to ensure that by adjusting the bearing capacity generated by the liquid metal in the two sections, the equivalent point of action of the resultant force can be precisely matched with the center of gravity of the rotating body. This further improves the stability of the anode rotating body during high-speed rotation, avoids vibration problems caused by deviations in the position of the resultant force, and ensures the focusing accuracy of the electron beam.

[0030] Furthermore, the first bearing capacity is greater than the second bearing capacity. Combined with the structural design of the first section being closer to the anode target, the combined bearing capacity generated by the liquid metal in the two sections can be shifted to the anode target side in a targeted manner. This eliminates the need for additional center of gravity adjustment of the anode assembly, simplifies the structural design process of the anode assembly, and ensures the support strength of the liquid metal bearing for the rotating body, thereby improving the stability of the bearing operation.

[0031] Furthermore, parameters such as the depth, density, width, and width-to-slot ratio of the trench can all be used as the basis for adjusting the trench pattern, providing diverse implementation paths for controlling the load-bearing capacity generated by the liquid metal in the two sections. The control parameters can be flexibly selected according to the weight of the anode target of different specifications and the rotor structure, adapting to the design requirements of different CT tube models, enhancing the versatility and adaptability of the anode assembly, and facilitating precise control of the load-bearing capacity by adjusting one or more parameters.

[0032] Furthermore, the width-to-slot ratio of the first groove is smaller than that of the second groove. This specific parameter difference allows for precise adjustment of the load-bearing capacity generated by the liquid metal in the two sections. This optimizes the flow state of the liquid metal within the grooves, ensuring that the pressure distribution of the liquid metal film formed in the two sections better matches the needs of the rotating center of gravity offset, guaranteeing that the point of equivalent force application precisely coincides with the rotating center of gravity. Simultaneously, it improves the lubrication effect and load-bearing capacity of the liquid metal bearing, extending its service life.

[0033] Furthermore, the depth, density, and width of the first trench are all greater than those of the second trench, or the axial length of the first section is greater than that of the second section. This further enhances the load-bearing capacity output generated by the liquid metal in the first section, better aligning with the structural characteristics of the rotating center of gravity being biased towards the anode target. Simultaneously, it optimizes the formation quality of the liquid metal film, improves the fluidity and lubrication performance of the liquid metal within the trench, reduces frictional losses during relative rotation between the outer and central shafts, enhances the high-speed rotation support capability of the bearing, and extends the service life of the anode assembly.

[0034] Furthermore, the cap can effectively seal the filling cavity to prevent liquid metal from leaking during the high-speed rotation of the anode rotor. The anti-overflow groove further enhances the anti-leakage effect, avoiding the problem of reduced bearing lubrication and support performance caused by liquid metal loss, ensuring the stable operation of the liquid metal bearing, reducing the probability of bearing failure, and extending the overall service life of the CT tube. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of an anode assembly according to an embodiment of this application;

[0036] Figure 2 yes Figure 1 Schematic diagram of the central axis section;

[0037] Figure 3 yes Figure 2 A schematic diagram of a variation of the structure shown;

[0038] Figure 4 yes Figure 2 A schematic diagram of another variation of the structure shown;

[0039] Figure 5 yes Figure 2 A schematic diagram of another variation of the structure shown;

[0040] Figure 6 yes Figure 2 A schematic diagram of another variation of the structure shown;

[0041] Figure 7 yes Figure 1 The diagram shows the principle of the first and second bearing capacities in the structure shown. Detailed Implementation

[0042] As described in the background section, the anode target disk of existing CT tubes needs to rotate at high speed driven by a liquid metal bearing to avoid localized high-temperature melting. The liquid metal forms a liquid metal film under the guidance of the inner bearing guide groove. The load-bearing force generated by the pressure difference needs to be matched with the center of gravity of the rotating anode to ensure stable operation. However, due to the large weight of the anode target disk, the center of gravity of the rotating disk is usually biased to one side of the target disk. In the traditional structure, the resultant force of the load-bearing force formed by the guide groove is fixed, making it difficult to match the two. If adjustments are made by increasing the weight of the rotor, reducing the weight of the target disk, or increasing the bearing volume, it will cause problems such as increased bearing load and decreased CT scanning power.

[0043] To address the aforementioned technical problems, this invention provides an anode assembly for a CT tube, comprising: an anode target; a rotor for driving the anode target to rotate; a central shaft portion including at least a first mating section along its axial direction, the axial direction of the central shaft portion being parallel to a first direction; and an outer shaft portion sleeved on the first mating section. The anode target and the rotor are respectively connected to the two ends of the outer shaft portion along the first direction. A filling cavity is formed between the central shaft portion and the outer shaft portion, and the filling cavity is filled with liquid metal. Under the drive of the rotor, the anode target rotates with the outer shaft portion about the central shaft portion. Along the first direction, the first mating section includes a first segment and a second segment, the first segment being closer to the anode target than the second segment. The outer peripheral surface of the first section has multiple first grooves spaced apart, and the outer peripheral surface of the second section has multiple second grooves spaced apart. The first grooves and the second grooves are used to guide the liquid metal to form a liquid metal film with pressure distribution on the surface of the first mating section. The first pattern formed by the multiple first grooves on the outer peripheral surface of the first section is different from the second pattern formed by the multiple second grooves on the outer peripheral surface of the second section, so that the effective point of the resultant force of the first bearing force generated by the liquid metal film on the outer shaft portion by the first section and the second bearing force generated by the liquid metal film on the outer shaft portion by the second section coincides with the center of gravity of the rotating body formed by the anode target, the rotor and the outer shaft portion.

[0044] By employing the technical solution of this application, the first mating section of the central shaft is divided into a first section closer to the anode target and a second section relatively farther away, and the groove patterns of the two sections are different. This allows for targeted adjustment of the magnitude of the first and second bearing forces generated by the liquid metal in the two sections. Consequently, the effective point of application of the resultant force of the bearing forces precisely coincides with the center of gravity of the rotating mass formed by the anode target, rotor, and outer shaft, improving the operational performance and reliability of the liquid metal bearing, while simultaneously enhancing the design flexibility of the CT tube anode structure.

[0045] To make the above-mentioned objectives, features and beneficial effects of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0046] Figure 1 This is a schematic diagram of an anode component 10 according to an embodiment of this application.

[0047] refer to Figure 1 The anode assembly 10 can be used in a CT tube. The CT tube can be used as the X-ray source for a CT scanner. Its working principle is that under the influence of the electric field between the anode and cathode, the electron beam emitted from the cathode is accelerated, and the accelerated electron beam bombards the anode target disk, generating X-rays through bremsstrahlung effect for medical imaging scanning.

[0048] Because the electron beam that bombards the surface of the anode target has an extremely high energy density, if the anode target remains stationary, a large amount of heat will quickly accumulate locally, causing it to melt. Therefore, the anode target must operate in the form of a rotating anode, rotating at high speed under the drive mechanism to evenly distribute the bombardment points of the electron beam on the surface of the target, thereby achieving rapid heat conduction and diffusion.

[0049] Furthermore, liquid metal bearings can be used in CT tubes to provide support and lubrication for the rotating anode. Liquid metal bearings are characterized by low friction, high thermal conductivity, and long lifespan, and consist of inner and outer bearing structures filled with liquid metal. During CT tube operation, the rotating anode needs to maintain a stable, high-speed rotational posture without significant unbalanced vibration. If the center of gravity of the rotating body does not coincide with the point of application of the resultant force of the bearing load, vibration will occur. This will not only affect the bombardment accuracy of the electron beam and the stability of X-ray generation, leading to a decrease in the imaging quality of the CT equipment, but also accelerate bearing wear, reducing the overall lifespan and operational reliability of the CT tube.

[0050] In some embodiments, the anode assembly 10 may include: an anode target 1; a rotor 2 for driving the anode target 1 to rotate; a central shaft portion 3, including at least a first mating section 31 along the axial direction, the axial direction of the central shaft portion 3 being parallel to a first direction D1; and an outer shaft portion 4 sleeved on the first mating section 31. The anode target 1 and the rotor 2 are respectively connected to the two ends of the outer shaft portion 4 along the first direction D1. A filling cavity is formed between the central shaft portion 3 and the outer shaft portion 4, the filling cavity being filled with liquid metal. Under the drive of the rotor 2, the anode target 1 rotates with the outer shaft portion 4 about the central shaft portion 3. Along the first direction D1, the first mating section 31 includes a first section 311 and a second section 312. The first section 311 is closer to the anode target 1 than the second section 312. Multiple first grooves G1 are spaced apart on the outer peripheral surface of segment 311, and multiple second grooves G2 are spaced apart on the outer peripheral surface of the second segment 312. The first grooves G1 and the second grooves G2 are used to guide the liquid metal to form a liquid metal film with pressure distribution on the surface of the first mating segment 31. The first pattern formed by the multiple first grooves G1 on the outer peripheral surface of the first segment 311 is different from the second pattern formed by the multiple second grooves G2 on the outer peripheral surface of the second segment 312, so that the effective point of the resultant force of the first bearing force generated by the first segment 311 on the outer shaft portion 4 through the liquid metal film and the second bearing force generated by the second segment 312 on the outer shaft portion 4 through the liquid metal film coincides with the center of gravity of the rotating body formed by the anode target 1, the rotor 2 and the outer shaft portion 4.

[0051] Specifically, the anode target 1 is used to receive the accelerated electron beam emitted from the cathode of the CT tube, and generates X-rays through bremsstrahlung to provide a radiation source for medical imaging scans. The rotor 2, as a power drive component, forms a transmission connection with the anode target 1 to drive the anode target 1 to rotate at high speed, avoiding localized high-temperature melting caused by the continuous bombardment of the anode target 1 by the electron beam at the same location.

[0052] Furthermore, the central shaft portion 3 extends along the first direction D1, and the axial direction of the central shaft portion 3 remains parallel to the first direction D1, providing a fixed support base for the entire anode assembly 10. The central shaft portion 3 is provided with at least one first mating section 31 along the axial direction. The first mating section 31 is used to form an assembly fit with the outer shaft portion 4 and is the mating area for realizing rotational support and lubrication.

[0053] Furthermore, the outer shaft portion 4 has a sleeve-like structure and is sleeved on the first mating section 31 of the central shaft portion 3. After the outer shaft portion 4 and the first mating section 31 are assembled, they form a clearance fit. The anode target 1 and the rotor 2 are respectively fixedly connected to the two ends of the outer shaft portion 4 along the first direction D1.

[0054] In some embodiments, the anode target 1 and the rotor 2 can be fixed by welding, fastener connection or other means to ensure that the torque output by the rotor 2 can be transmitted to the anode target 1 through the outer shaft part 4 and drive the anode target 1 to rotate.

[0055] Furthermore, after the central shaft portion 3 and the outer shaft portion 4 are fitted together, an annular filling cavity is formed between them. This filling cavity is used to fill liquid metal. Liquid metal has the characteristics of low friction and high thermal conductivity, which can form a lubrication and load-bearing structure during component operation, ensuring the high-speed rotation of the outer shaft portion 4. Driven by the rotor 2, the outer shaft portion 4 rotates around the central shaft portion 3 as the rotation axis, and the anode target 1 rotates synchronously at high speed with the outer shaft portion 4, realizing the uniform dispersion of the electron beam bombardment points.

[0056] In some embodiments, along the first direction D1, the first mating segment 31 includes two independent segments, namely the first segment 311 and the second segment 312. The first segment 311 is positioned closer to the anode target 1 than the second segment 312. This positioning can adapt to the distribution characteristics of the center of gravity of the rotating target, laying a structural foundation for the subsequent precise control of the load-bearing capacity.

[0057] In one variation, the first mating section 31 may also include other sections, thereby achieving more precise control over the distribution of the bearing capacity.

[0058] In some embodiments, a plurality of first grooves G1 are uniformly spaced along the circumferential direction on the outer peripheral surface of the first section 311. Similarly, a plurality of second grooves G2 are uniformly spaced along the circumferential direction on the outer peripheral surface of the second section 312.

[0059] In some embodiments, the extending directions of the first groove G1 and the second groove G2 are adapted to the rotation direction of the outer shaft portion 4, so as to guide the liquid metal in the filling cavity to form a continuous liquid metal film with a specific pressure distribution on the outer surface of the first mating section 31.

[0060] Furthermore, multiple first trenches G1 together form a first pattern on the outer peripheral surface of the first section 311, and multiple second trenches G2 together form a second pattern on the outer peripheral surface of the second section 312. The first pattern and the second pattern are different from each other. This pattern difference will directly affect the flow state of the liquid metal in the trenches, thereby changing the pressure distribution characteristics of the liquid metal film.

[0061] Furthermore, the liquid metal film at the first section 311 generates a first load-bearing force on the outer shaft portion 4, and the liquid metal film at the second section 312 generates a second load-bearing force on the outer shaft portion 4. Due to the difference between the first pattern and the second pattern, the magnitudes of the first load-bearing force and the second load-bearing force will form a specific proportional relationship.

[0062] In some embodiments, the anode target 1, rotor 2, and outer shaft 4 together constitute a rotating body, which has a fixed center of gravity position. Therefore, by designing the difference between the first and second patterns, the ratio of the first and second bearing forces can be adjusted so that the equivalent point of application of the resultant force formed by the combined action of the first and second bearing forces coincides with the center of gravity of the rotating body. Thus, the rotating body can achieve dynamic balance during high-speed rotation, avoiding vibration problems caused by the offset between the center of gravity and the equivalent point of application of the resultant force, reducing component wear, ensuring the operational stability and reliability of the anode assembly 10, and eliminating the need to adjust the center of gravity by increasing the weight of the rotor, reducing the weight of the target disk, or increasing the bearing volume, thereby improving the design flexibility of the CT tube anode structure.

[0063] In some embodiments, combined with Figure 1 and Figure 7 The first pattern and the second pattern are correlated so that the first bearing capacity and the second bearing capacity satisfy: F1×L1=F2×L2, where F1 is the first bearing capacity; F2 is the second bearing capacity; L1 is the distance between the equivalent point of action of the first bearing capacity and the equivalent point of action of the resultant force; L2 is the distance between the equivalent point of action of the second bearing capacity and the equivalent point of action of the resultant force.

[0064] It should be understood that, in order to clearly illustrate the first bearing capacity, the second bearing capacity, their resultant force, and the equivalent point of application, etc. Figure 7 Other structures are not identified, but their functions and roles are similar to those of others. Figure 1 The same, therefore, the following text is combined. Figure 1 and Figure 7 The specific implementation methods are described.

[0065] As described above, in Figure 7 , the first bearing capacity F1 specifically refers to the supporting force exerted on the inner wall of the outer shaft portion 4 by the liquid metal film formed by guiding liquid metal in the first groove G1 of the first section 311; the second bearing capacity F2 specifically refers to the supporting force exerted on the inner wall of the outer shaft portion 4 by the liquid metal film formed by guiding liquid metal in the second groove G2 of the second section 312. L1 is the linear distance from the equivalent action point of the first bearing capacity F1 to the equivalent action point of the resultant force jointly formed by F1 and F2; L2 is the linear distance from the equivalent action point of the second bearing capacity F2 to the equivalent action point of the resultant force.

[0066] In view of the actual working requirements of the CT tube anode assembly 10, since the anode target 1 is relatively heavy, the center of gravity of the rotating body jointly composed of the anode target 1, the rotor 2 and the outer shaft portion 4 will be biased towards the anode target 1 side (i.e., the direction close to the first section 311). Therefore, through the associated design of the first pattern and the second pattern, the first bearing capacity F1 needs to be greater than the second bearing capacity F2. According to the torque balance relationship of "F1×L1 = F2×L2", when F1 > F2, it is inevitable that L1 < L2, that is, the distance from the equivalent action point of the first bearing capacity F1 to the equivalent action point of the resultant force is less than the distance from the equivalent action point of the second bearing capacity F2 to the equivalent action point of the resultant force. That is to say, the equivalent action point of the resultant force is closer to the anode target to coincide with the center of gravity of the rotating body.

[0067] Through the torque balance design, the equivalent action point of the resultant force of F1 and F2 can be directly shifted precisely towards the side close to the anode target 1 until it coincides with the center of gravity of the rotating body biased towards the anode target 1. Without increasing the weight on the rotor 2 side, reducing the weight of the anode target 1 or increasing the bearing volume to adjust the center of gravity, the vibration caused by the offset between the center of gravity and the equivalent action point of the resultant force during the high-speed rotation of the rotating body can be avoided, which not only ensures the lubrication stability between the outer shaft portion 4 and the middle shaft portion 3, but also maintains the maximum heat capacity of the anode target 1 and avoids the increase of bearing load pressure, thereby ensuring the maximum scanning power and imaging accuracy of the CT tube and prolonging the service life of the anode assembly 10 and the entire CT tube.

[0068] In some embodiments, the structural parameters of the first groove G1 and the second groove G2 (such as the width ratio of the platform groove, the herringbone angle, the depth, the density, etc.) can be adjusted and determined through simulation experiments to achieve the torque balance relationship of F1×L1 = F2×L2 for the first bearing capacity F1 and the second bearing capacity F2, and the equivalent action point of the resultant force coincides with the center of gravity of the rotating body.

[0069] In some embodiments, the value of the first bearing capacity is greater than the value of the second bearing capacity.

[0070] In some embodiments, at least one parameter of the first trench G1 and the second trench G2 is different to make the first pattern different from the second pattern. The parameter includes at least the depth, density, width, and platform-to-trough width ratio of the trench. Thus, by adjusting the above parameters, the flow path, capacity, or constraint strength of the liquid metal in the trench can be directly changed, thereby adjusting the pressure distribution of the liquid metal film on the surfaces of the first section 311 and the second section 312, ultimately making the first bearing capacity and the second bearing capacity adapt to the size relationship of the center of gravity of the rotation.

[0071] In some embodiments, combined with Figure 1 and Figure 4 The width ratio of the first groove G1 to the groove is smaller than the width ratio of the second groove G2.

[0072] The platform-to-groove width ratio refers to the ratio of the platform width (the width of the flat area between two adjacent grooves without grooves) to the width of the groove itself.

[0073] In a typical application scenario, when the width of the first trench G1 is relatively small, the proportion of the trench on the outer circumference of the first section 311 is relatively large, while the proportion of the platform is small. When the liquid metal rotates with the outer shaft 4, the path guided by the trench is denser, and the flow will not be interrupted due to the excessive width of the platform. This allows for the formation of a more uniform and stable liquid metal film on the surface of the first section 311. Conversely, the second trench G2 has a larger width, a smaller proportion of the trench, and a larger proportion of the platform. The liquid metal will contact the platform surface more during flow, resulting in a more dispersed pressure distribution in the film. This difference in the trench width ratio causes the first pattern to exhibit a "dense trench, narrow platform" characteristic, while the second pattern exhibits a "sparse trench, wide platform" characteristic. The two structures are significantly different, ultimately causing the first load-bearing force generated by the liquid metal film of the first section 311 on the outer shaft 4 to be greater than the second load-bearing force generated by the liquid metal film of the second section 312. The combined force shifts towards the side closer to the anode target 1, adapting to the rotational center of gravity of the target disk.

[0074] In some embodiments, the width-to-slot ratio of the first trench G1 is between 0.3:1 and 0.9:1.

[0075] In some embodiments, the width-to-slot ratio of the second trench G2 is from 1:1 to 2:1.

[0076] In some embodiments, the ratio of the width ratio of the first trench G1 to the width ratio of the second trench G2 is 1:1.2 to 1:3.5.

[0077] In a preferred embodiment, the width-to-slot ratio of the first trench G1 is 1:3, and the width-to-slot ratio of the second trench G2 is 1:1.

[0078] In some embodiments, combined with Figure 1 and Figure 2 The depth of the first trench G1 is greater than the depth of the second trench G2. Therefore, the pressure distribution of the liquid metal film can be altered through this depth difference, resulting in a greater first bearing capacity than the second bearing capacity, satisfying F1×L1=F2×L2. The deeper first trench G1 can hold more liquid metal, and when the rotor 2 drives the outer shaft 4 to rotate at high speed, the containment and constraint of the liquid metal is stronger, and the liquid metal is subjected to a more significant dual effect of centrifugal force and trench wall compression, resulting in a higher pressure in the formed liquid metal film. Conversely, the shallower second trench G2 holds less liquid metal, has a weaker constraint on the liquid metal, and a relatively lower pressure in the liquid metal film. Ultimately, this results in a greater first bearing capacity than the second bearing capacity, causing the resultant bearing force to shift towards the first section 311 (closer to the anode target 1), adapting to the center of gravity of the rotating mass.

[0079] In some specific embodiments, the depth of the first trench G1 can be set to 0.6mm~1.0mm, and the depth of the second trench G2 can be set to 0.3mm~0.5mm.

[0080] In some embodiments, combined with Figure 1 and Figure 6 The density of the first trench G1 is greater than the density of the second trench G2. Here, trench density refers to the number of trenches per unit axial length. The higher-density first trench G1 can more frequently guide and divert the liquid metal within the axial direction (i.e., the first direction D1) of the first section 311, preventing pressure attenuation due to excessive axial flow distance. This results in a more uniform pressure distribution and a higher overall pressure value for the liquid metal film in the first section 311. Conversely, the lower-density second trench G2 guides the liquid metal less frequently, resulting in a longer flow distance between adjacent trenches and relatively dispersed pressure in the film. This creates a bearing capacity relationship where the first trench has a greater bearing capacity than the second, helping to shift the equivalent point of application of the resultant force to match the center of gravity.

[0081] In some embodiments, the width of the first trench G1 is greater than the width of the second trench G2. The wider first trench G1 allows more liquid metal to enter the trench simultaneously, resulting in lower flow resistance and faster filling of the trench to form a complete and sufficiently pressurized liquid metal film. In contrast, the narrower second trench G2 restricts the flow rate of liquid metal, requiring a longer time for the liquid metal to fill the trench. This leads to a slower film formation rate and the potential for localized pressure weaknesses, resulting in an overall pressure lower than that of the liquid metal film corresponding to the first trench G1.

[0082] In one specific embodiment, the width of the first groove G1 can be set to 1.0mm~1.5mm, and the width of the second groove G2 can be set to 0.6mm~0.9mm.

[0083] It should be understood that the density and width can be adjusted simultaneously.

[0084] In some embodiments, combined with Figure 1 and Figure 5 The axial length of the first segment 311 can be greater than the axial length of the second segment 312. As the core bearing area close to the anode target 1, the longer axial length of the first segment 311 can provide a larger distribution space for the first groove G1, making the first bearing force have a wider range of action and a more uniform distribution, forming a more reasonable torque ratio with the second bearing force of the second segment 312; combined with the torque balance relationship (F1×L1=F2×L2), the longer first segment 311 can further shorten the value of L1, ensuring that the resultant force shifts towards the center of gravity of the rotating body.

[0085] In some non-limiting embodiments, one or more of the above parameters can be selected and adjusted according to the actual offset of the center of gravity of the rotating body. For example, a combination of "first groove G1 depth 0.8mm, width 1.2mm" and "second groove G2 depth 0.4mm, width 0.7mm" can be used simultaneously, or a length configuration of "first section 311 axial length 32mm, second section 312 axial length 22mm" can be used to further improve the accuracy of load-bearing capacity control through the synergistic effect of multiple parameters, ensuring that the equivalent point of application of the resultant force is completely coincident with the center of gravity of the rotating body. Thus, this multi-parameter combination design method does not require the traditional solution of increasing the weight of rotor 2, reducing the weight of anode target 1, or increasing the bearing volume. It avoids the problems of increased bearing load and reduced CT scanning power, while maintaining the characteristics of low friction, high thermal conductivity, and long life of liquid metal bearings, and at the same time improving the design flexibility and adaptability of the CT tube anode structure.

[0086] In some embodiments, the first groove G1 and the second groove G2 are both herringbone grooves, and the herringbone angle of the first groove G1 is greater than the herringbone angle of the second groove G2.

[0087] In practical applications, the size of the herringbone angle directly affects the guiding and squeezing effect of the trench on the liquid metal. The larger the angle, the more concentrated the flow path of the liquid metal in the trench, the more significant the squeezing intensity of the trench wall, the higher the pressure of the liquid metal film formed, and the greater the corresponding bearing capacity.

[0088] In the embodiments of the present application, the first section 311 is close to the anode target 1 and needs to generate a greater first bearing capacity to adapt to the center of gravity of the rotating body biased towards the target disc. Therefore, by setting "the herringbone angle of the first groove G1 is greater than the herringbone angle of the second groove G2", the pressure of the liquid metal film formed by the first groove G1 guiding the liquid metal is higher, and then the bearing capacity relationship that the first bearing capacity is greater than the second bearing capacity is realized. Combining with the principle of moment balance (F1×L1 = F2×L2), the resultant force of the bearing capacity is offset towards the first section 311 and coincides with the center of gravity of the rotating body.

[0089] In some embodiments, the herringbone angle of the first groove G1 ranges from 75° to 110°.

[0090] In some embodiments, the herringbone angle of the second groove G2 ranges from 50° to 80°.

[0091] In some embodiments, the difference between the herringbone angle of the first groove G1 and the herringbone angle of the second groove G2 is 15° to 30°.

[0092] In some embodiments, in combination with Figure 1 and Figure 3 , the herringbone groove of the first groove G1 can be disconnected in the middle. That is, only the grooves on both sides of the herringbone groove are retained and do not include the sharp corners, forming a structure similar to the character "八" (eight).

[0093] In practical applications, according to the principle of fluid mechanics, a liquid metal retention area is likely to form at the sharp corners of the herringbone groove, resulting in too high or fluctuating local film pressure; after the "八" - shaped disconnection, the middle blank platform replaces the sharp corners, and the liquid metal flows independently in the two side groove segments without intersection and retention, and the pressure of the liquid metal film can be evenly distributed along the axial direction of the first section 311. This makes the output of F1 more stable, without local pressure mutation, and avoids the problem of unstable bearing support caused by fluctuating bearing capacity.

[0094] It should be understood that the above "八" - shaped groove only removes the sharp - corner intersection area of the herringbone groove and does not change the core parameters of the first groove G1 (density, depth, and herringbone angle are still greater than those of the second groove G2). The two independent oblique groove segments on both sides can still fully guide the flow of the liquid metal, making the intensity of the liquid metal being extruded by the groove wall sufficient, and the pressure of the finally formed liquid metal film is still higher than the film pressure corresponding to G2 in the second section. Therefore, the fact that the first bearing capacity is greater than the second bearing capacity will not be weakened due to the disconnection design, and it can still meet the core requirement that the equivalent action point of the resultant force shifts towards the anode target side.

[0095] In some embodiments, the first groove G1 and the second groove G2 are formed by milling process, electric discharge machining process or laser engraving process.

[0096] In some embodiments, the processes for forming the first trench G1 and the second trench G2 are different.

[0097] In some embodiments, continue to refer to Figure 1 The anode assembly 10 further includes a capping portion 5 having a central through hole extending along the first direction D1. The capping portion 5 is fitted onto the central shaft portion 3 and closes the opening of the filling cavity away from the anode target 1. The capping portion 5 rotates synchronously with the outer shaft portion 4. At least one anti-overflow groove is formed on the wall of the capping portion 5 forming the central through hole. Thus, the capping portion 5 is positioned corresponding to the opening of the filling cavity away from the anode target 1 (the filling cavity is an annular cavity formed after the central shaft portion 3 and the outer shaft portion 4 are fitted together). The capping portion 5 is used to close the opening, preventing the liquid metal in the filling cavity from directly contacting the outside, reducing the evaporation loss of the liquid metal, and at the same time blocking external impurities from entering the filling cavity, preventing impurities from affecting the lubrication performance of the liquid metal.

[0098] This application embodiment also provides a CT tube, including: as described above Figures 1 to 7 The anode assembly 10 shown in the illustrated embodiment or similar thereto.

[0099] The specific structure and operation of the anode assembly 10 are as described above and will not be repeated here.

[0100] This application embodiment also provides a method for processing an anode assembly for a CT tube, comprising: providing an anode target, a rotor, a central shaft portion, and an outer shaft portion, wherein the central shaft portion includes a first mating section along the axial direction; forming multiple first grooves on the outer peripheral surface of a first section of the first mating section; forming multiple second grooves on the outer peripheral surface of a second section of the first mating section; fitting the outer shaft portion onto the first mating section of the central shaft portion; connecting the anode target and the rotor to the two ends of the outer shaft portion respectively; forming a filling cavity between the assembled central shaft portion and the outer shaft portion; and filling the filling cavity with liquid metal; wherein the first pattern formed by the multiple first grooves on the outer peripheral surface of the first section is different from the second pattern formed by the multiple second grooves on the outer peripheral surface of the second section, such that the equivalent point of the resultant force of the first bearing force generated by the liquid metal film on the outer shaft portion by the first section and the second bearing force generated by the liquid metal film on the outer shaft portion by the second section coincides with the center of gravity of the rotating body jointly formed by the anode target, the rotor, and the outer shaft portion.

[0101] Furthermore, the first pattern and the second pattern are graphically correlated so that the first bearing capacity and the second bearing capacity satisfy: F1×L1=F2×L2, where F1 is the first bearing capacity; F2 is the second bearing capacity; L1 is the distance between the equivalent point of action of the first bearing capacity and the equivalent point of action of the resultant force; and L2 is the distance between the equivalent point of action of the second bearing capacity and the equivalent point of action of the resultant force.

[0102] In some embodiments, the parameters of the first trench and the second trench are determined through simulation experiments.

[0103] It should be understood that the method described can be used to process the aforementioned... Figures 1 to 7 The anode assembly 10 shown in the illustrated embodiment or similar thereto.

[0104] The specific structure and operation of the anode assembly 10 are as described above and will not be repeated here.

[0105] Based on the above, by adopting the technical solution of this application, the first mating section 31 of the central shaft 3 is divided into a first section 311 closer to the anode target 1 and a second section 312 relatively farther away, and the groove patterns of the two sections are different. This allows for targeted adjustment of the magnitude of the first and second bearing forces generated by the liquid metal in the two sections. Furthermore, the effective point of application of the resultant force of the bearing forces is precisely aligned with the center of gravity of the rotating body formed by the anode target 1, rotor 2, and outer shaft 4, improving the operating performance and reliability of the liquid metal bearing and enhancing the design flexibility of the anode structure of the CT tube 100.

[0106] Furthermore, the matching relationship between the first bearing capacity, the second bearing capacity, and the distance between their corresponding equivalent points of action and the equivalent point of action of the resultant force provides a theoretical basis for the precise control of the equivalent point of action of the resultant force. Through this matching relationship, it is possible to ensure that by adjusting the bearing capacity generated by the liquid metal in the two sections, the equivalent point of action of the resultant force is precisely matched with the center of gravity of the rotating body. This further improves the stability of the anode rotating body during high-speed rotation, avoids vibration problems caused by deviations in the position of the resultant force, and ensures the focusing accuracy of the electron beam.

[0107] Furthermore, the first bearing capacity is greater than the second bearing capacity. Combined with the structural design of the first section 311 being closer to the anode target 1, the combined bearing capacity generated by the liquid metal in the two sections can be shifted to the anode target 1 side in a targeted manner. This eliminates the need for additional center of gravity adjustment of the anode assembly 10, simplifies the structural design process of the anode assembly 10, and ensures the support strength of the liquid metal bearing for the rotating body, thereby improving the stability of the bearing operation.

[0108] Furthermore, parameters such as the depth, density, width, and width-to-slot ratio of the trench can all be used as the basis for adjusting the trench pattern, providing diverse implementation paths for controlling the load-bearing capacity generated by the liquid metal in the two sections. The control parameters can be flexibly selected according to the weight of the anode target 1 of different specifications and the structure of the rotor 2, adapting to the design requirements of different models of CT tube 100, enhancing the versatility and adaptability of the anode assembly 10, and facilitating precise control of the load-bearing capacity by adjusting one or more parameters.

[0109] Furthermore, the width ratio of the first groove G1 is smaller than that of the second groove G2. This specific parameter difference allows for precise adjustment of the load-bearing capacity generated by the liquid metal in the two sections. This optimizes the flow state of the liquid metal within the grooves, ensuring that the pressure distribution of the liquid metal film formed in the two sections better matches the needs of the rotating center of gravity offset, guaranteeing that the point of equivalent force application precisely coincides with the rotating center of gravity. Simultaneously, it improves the lubrication effect and load-bearing capacity of the liquid metal bearing, extending its service life.

[0110] Furthermore, the depth, density, and width of the first trench G1 are greater than those of the second trench G2, or the axial length of the first section 311 is greater than that of the second section 312. This further enhances the load-bearing capacity output generated by the liquid metal corresponding to the first section 311, better aligning with the structural characteristics of the rotating center of gravity being biased towards the anode target 1. Simultaneously, it optimizes the formation quality of the liquid metal film, improves the fluidity and lubrication performance of the liquid metal within the trench, reduces frictional losses during relative rotation between the outer shaft portion 4 and the central shaft portion 3, enhances the high-speed rotation support capability of the bearing, and extends the service life of the anode assembly 10.

[0111] Furthermore, the capping part 5 can effectively seal the filling cavity to prevent the liquid metal from leaking during the high-speed rotation of the anode rotating body. The anti-overflow groove further enhances the anti-leakage effect, avoids the problem of reduced bearing lubrication and support performance caused by liquid metal loss, ensures the stable operation of the liquid metal bearing, reduces the probability of bearing failure, and extends the overall service life of the CT tube 100.

[0112] It should be understood that the term "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. Additionally, the character " / " in this document indicates that the preceding and following related objects are in an "or" relationship. As used herein, unless explicitly stated otherwise, the term "or" covers all possible combinations unless impractical. For example, if a component is declared to include A or B, then unless explicitly stated otherwise or impractical, the component can include A, or B, or A and B. As a second example, if a component is declared to include A, B, or C, then unless explicitly stated otherwise or impractical, the component can include A, or B, or C, or A and B, or A and C, or B and C, or A and B and C.

[0113] In this disclosure, "multiple" refers to two or more.

[0114] Relational terms appearing in the embodiments of this disclosure, such as "first," "second," etc., are used only to distinguish an entity or operation from another entity or operation, without requiring or implying any actual relationship or order between these entities or operations. Furthermore, the words "comprising," "having," and "including," and other similar forms, are intended to be equivalent in meaning and are open-ended; one or more items following any of these words do not imply an exhaustive list of such items or that they are limited to only the listed items. Exemplary embodiments have been disclosed in the drawings and specification. However, many variations and modifications can be made to these embodiments. Therefore, although specific terminology is used, it is used only in a general and descriptive sense and not for limiting purposes.

[0115] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. An anode assembly for a CT X-ray tube, characterized in that, include: Anode target; A rotor is used to drive the anode target to rotate; The central shaft portion includes at least a first mating section along the axial direction, wherein the axial direction of the central shaft portion is parallel to a first direction; An outer shaft portion is fitted onto the first mating section. The anode target and the rotor are respectively connected to both ends of the outer shaft portion along the first direction. A filling cavity is formed between the central shaft portion and the outer shaft portion, and the filling cavity is filled with liquid metal. Driven by the rotor, the anode target rotates with the outer shaft portion about the central shaft portion as an axis. Along the first direction, the first mating section includes a first section and a second section. The first section is closer to the anode target than the second section. The outer peripheral surface of the first section has a plurality of first grooves spaced apart, and the outer peripheral surface of the second section has a plurality of second grooves spaced apart. The first grooves and the second grooves are used to guide the liquid metal to form a liquid metal film with pressure distribution on the surface of the first mating section. The first pattern formed by multiple first grooves on the outer peripheral surface of the first section is different from the second pattern formed by multiple second grooves on the outer peripheral surface of the second section, so that the effective point of the resultant force of the first bearing force generated by the first section on the outer shaft through the liquid metal film and the second bearing force generated by the second section on the outer shaft through the liquid metal film coincides with the center of gravity of the rotating body jointly formed by the anode target, the rotor and the outer shaft.

2. The anode assembly according to claim 1, characterized in that, The first pattern and the second pattern are graphically correlated to ensure that the first load-bearing capacity and the second load-bearing capacity satisfy the following: F1×L1=F2×L2, where F1 represents the first bearing capacity; F2 represents the second bearing capacity; L1 is the distance between the equivalent point of action of the first bearing force and the equivalent point of action of the resultant force; L2 is the distance between the equivalent point of action of the second bearing force and the equivalent point of action of the resultant force.

3. The anode assembly according to claim 1, characterized in that, The value of the first bearing capacity is greater than the value of the second bearing capacity.

4. The anode assembly according to claim 1, characterized in that, The first groove and the second groove have at least one parameter that is different to make the first pattern different from the second pattern. The parameter includes at least the depth, density, width, and groove width ratio of the groove.

5. The anode assembly according to claim 4, characterized in that, The width-to-slot ratio of the first trench is smaller than that of the second trench.

6. The anode assembly according to claim 5, characterized in that, The width-to-slot ratio of the first trench ranges from 0.3:1 to 0.9:1; and / or The width-to-slot ratio of the second trench is between 1:1 and 2:1; and / or The ratio of the width of the first groove to the width of the second groove is 1:1.2 to 1:3.

5.

7. The anode assembly according to claim 4, characterized in that, The depth of the first trench is greater than the depth of the second trench; and / or The density of the first trench is greater than the density of the second trench; and / or The width of the first trench is greater than the width of the second trench; and / or The axial length of the first segment is greater than the axial length of the second segment.

8. The anode assembly according to claim 1, characterized in that, Both the first groove and the second groove are herringbone grooves, and the herringbone angle of the first groove is greater than that of the second groove.

9. The anode assembly according to claim 8, characterized in that, The herringbone angle of the first groove ranges from 75° to 110°; and / or The herringbone angle of the second groove is between 50° and 80°; and / or The difference between the herringbone angle of the first groove and the herringbone angle of the second groove is 15°~30°.

10. The anode assembly according to claim 1, characterized in that, The first groove and the second groove are formed by milling, electrical discharge machining, or laser engraving; and / or The processes for forming the first trench and the second trench are different.

11. The anode assembly according to claim 1, characterized in that, Also includes: The sealing portion has a central through hole extending along the first direction. The sealing portion is sleeved on the central shaft portion and closes the opening of the filling cavity away from the anode target. The sealing portion rotates synchronously with the outer shaft portion. At least one anti-overflow groove is formed on the wall of the sealing portion forming the central through hole.

12. A CT X-ray tube, characterized in that, include: The anode assembly as described in any one of claims 1-11.

13. A method for processing an anode assembly for a CT tube, characterized in that, include: An anode target, a rotor, a central shaft portion, and an outer shaft portion are provided, wherein the central shaft portion includes a first mating section along the axial direction; Multiple first grooves are opened on the outer periphery of the first section of the first mating section; Multiple second grooves are opened on the outer periphery of the second section of the first mating section; The outer shaft portion is fitted onto the first mating section of the central shaft portion, and the anode target and the rotor are respectively connected to both ends of the outer shaft portion. A filling cavity is formed between the assembled central shaft portion and the outer shaft portion, and liquid metal is filled into the filling cavity. The first pattern formed by multiple first grooves on the outer peripheral surface of the first section is different from the second pattern formed by multiple second grooves on the outer peripheral surface of the second section, so that the effective point of the resultant force of the first bearing force generated by the first section on the outer shaft through the liquid metal film and the second bearing force generated by the second section on the outer shaft through the liquid metal film coincides with the center of gravity of the rotating body jointly formed by the anode target, the rotor and the outer shaft.

14. The method according to claim 13, characterized in that, The first pattern and the second pattern are graphically correlated to ensure that the first load-bearing capacity and the second load-bearing capacity satisfy the following: F1×L1=F2×L2, where F1 represents the first bearing capacity; F2 represents the second bearing capacity; L1 is the distance between the equivalent point of action of the first bearing force and the equivalent point of action of the resultant force; L2 is the distance between the equivalent point of action of the second bearing force and the equivalent point of action of the resultant force.

15. The method according to claim 13, characterized in that, The parameters of the first trench and the second trench were determined through simulation experiments.

Images