X-ray tube with liquid metal bearings

Abstract

An X-ray tube using a liquid metal bearing comprises: a housing defining a housing cavity, the housing having first and second opposing sides along a first direction; an anode target disposed in the housing cavity; a central axis extending along the first direction and having first and second opposing ends; an outer shaft, the outer shaft being sleeved on a first mating section of the central axis and rotatable about the central axis, the second end being located in the first mating section, a non-zero first gap being defined between an inner wall of the outer shaft and an outer circumferential surface of the first mating section, the first gap forming at least a portion of a filling cavity filled with liquid metal, the first mating section, the outer shaft, and the liquid metal in the filling cavity cooperating to form a liquid metal bearing; and a support portion sleeved on the central axis, the support portion being fixedly connected to the outer shaft portion and rotating synchronously with the outer shaft portion, and at least a portion of the support portion selectively abutting the central axis portion in response to the rotational speed of the outer shaft portion. Thus, the X-ray tube can be reduced in wear and have a longer service life.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of X-ray tubes, and in particular to an X-ray tube using a liquid metal bearing. Background Art

[0002] As an indispensable core component in modern medical imaging technology, the performance and stability of X-ray tubes are directly related to the accuracy of medical diagnosis and patient safety.

[0003] The principle of X-ray generation in an X-ray tube is that the filament heats up to generate electrons. A large number of electrons are accelerated by the high-voltage electric field between the cathode and anode to bombard the anode target, thereby generating X-rays. The X-rays are reflected by the target surface and emitted from the window. After passing through the patient, they are received by the CT detector to form an image. The process of electron bombardment of the anode target generates a large amount of heat. If the bombardment position remains unchanged, the bombarded area of ​​the anode target will generate a large amount of heat, and the heat generation rate is much faster than the heat dissipation rate. When the heat accumulates to a critical value, the bombarded area of ​​the target surface melts, causing the anode to fail. Therefore, in the existing technology, X-ray tubes generally use a rotating anode, that is, the anode target is in a high-speed rotating state during operation. In this way, the position of the electron bombardment on the anode target continuously changes, avoiding the phenomenon of local temperature rise and damage to the anode target.

[0004] To reduce wear and extend the life of X-ray tubes, existing X-ray tubes can utilize liquid metal bearings. However, since the inner and outer bearings of these bearings are filled with liquid metal, they lack stable support. Consequently, contact and wear between the inner and outer bearings are unavoidable during startup and shutdown. For example, among the many types of X-ray tubes, CT tubes, with their unique operating mechanism, play a crucial role in CT scanning. Rotating anode CT tubes, for example, are frequently started and stopped during operation. During the transition from stationary to rotating or vice versa, the inner and outer bearings within the CT tube may come into direct contact and experience significant eccentricity, resulting in increased wear on one side of the bearings, seriously impacting the life of the X-ray tube. For example, when stationary, under the influence of gravity, the inner bearing, which connects the anode target and rotor, comes into contact with the outer bearing, with the inner and outer bearings experiencing greater compression on the side facing the direction of gravity. This results in uneven force between the inner and outer bearings of rotating parts (such as rotors and anode targets) when they go from stationary to moving. The side facing the direction of gravity will wear more severely, ultimately affecting the service life of the CT tube. Summary of the Invention

[0005] The technical problem solved by the present invention is to provide an X-ray tube which has low wear and a longer service life and adopts a liquid metal bearing.

[0006] To solve the above technical problems, an embodiment of the present invention provides an X-ray tube using a liquid metal bearing, comprising: a housing defining a housing cavity, the housing having opposite first and second sides along a first direction; an anode target disposed in the housing cavity; a central axis extending along the first direction and having opposite first and second ends, wherein the first end is fixedly connected to the first side; an outer axis connected to the anode target, the outer axis sleeved on a first mating section of the central axis and rotatable about the central axis, the second end located in the first mating section, a non-zero first gap between an inner wall of the outer axis and an outer circumferential surface of the first mating section, the first gap forming at least a portion of a filling cavity, the filling cavity being filled with liquid metal, the first mating section, the outer axis, and the liquid metal in the filling cavity cooperating to form a liquid metal bearing; and a support sleeved on the central axis, the support fixedly connected to the outer axis and rotating synchronously with the outer axis, and at least a portion of the support selectively abutting the central axis in response to the rotational speed of the outer axis.

[0007] Optionally, in response to the rotation speed of the outer shaft portion being less than a preset threshold, at least a portion of the support portion abuts against the middle shaft portion, and in response to the rotation speed of the outer shaft portion being greater than or equal to the preset threshold, the support portion separates from the middle shaft portion.

[0008] Optionally, the support portion includes: a ring portion, directly or indirectly connected to the end of the outer axis portion toward the first side; a plurality of retractable protrusions, spaced around the middle axis portion and arranged on the inner wall of the ring portion toward the middle axis portion, the protrusions being able to extend toward the middle axis portion to support the middle axis portion or retract in a direction away from the middle axis portion to separate from the middle axis portion.

[0009] Optionally, the support portion further includes a plurality of elastic members, the plurality of elastic members corresponding to the plurality of protrusions one-to-one, and the elastic members are used to push the corresponding protrusions to extend toward the central axis portion.

[0010] Optionally, a plurality of grooves are provided on the inner wall of the ring portion toward the central axis portion, and the plurality of grooves correspond one-to-one to the plurality of retractable protrusions. At least a portion of each protrusion and the corresponding elastic member are accommodated in the corresponding groove, and the protrusion can extend or retract into the corresponding groove under the push of the corresponding elastic member.

[0011] Optionally, as the rotational speed of the outer shaft portion increases, the protrusion retracts into the groove portion in a direction away from the middle shaft portion under the action of centrifugal force and compresses the elastic member.

[0012] Optionally, a non-zero second gap exists between the ring portion and the central shaft portion, and the second gap forms a part of the filling cavity.

[0013] Optionally, the ring portion is sleeved on the second fitting segment of the middle shaft portion, the cross-sectional area of ​​the second fitting segment is larger than the cross-sectional area of ​​the first fitting segment, and along the first direction, a non-zero third gap exists between the outer shaft portion and the second fitting segment, and the third gap connects the first gap and the second gap, and the third gap forms a part of the filling cavity.

[0014] Optionally, a texture array is provided on the first area of ​​the end face of the outer shaft portion facing the first side, and along the first direction, the projection of the second mating segment coincides with the first area. The texture array is used to drive the flow of the liquid metal in the filling cavity, and each texture array includes a plurality of guide grooves.

[0015] Optionally, it also includes: a covering portion having a central through hole extending along the first direction, the covering portion being sleeved on the central axis portion and closing the opening of the filling cavity toward the first side, the covering portion and the ring portion being fixedly connected, and the covering portion, the ring portion and the outer axis portion rotating synchronously.

[0016] Optionally, the sealing cover portion includes a sealing flange portion and a sleeve portion connected along the first direction, wherein the sealing flange portion is closer to the second side than the sleeve portion, and there is a non-zero fourth gap between the sealing flange portion and the central axis portion, and the fourth gap forms a part of the filling cavity; and the sleeve portion is provided with at least one anti-overflow groove on the inner wall facing the central axis portion.

[0017] Optionally, the middle axis portion includes a second mating segment, the cross-sectional area of ​​the second mating segment is larger than the cross-sectional area of ​​the first mating segment, along the first direction, the second mating segment is located between the outer axis portion and the cover portion, and a texture array is provided in a second area of ​​the end surface of the cover portion facing the second mating segment, the projection of the second mating segment along the first direction coincides with the second area, the texture array is used to drive the flow of the liquid metal in the filling cavity, and each of the texture arrays includes a plurality of guide grooves.

[0018] Optionally, a texture array is provided on an outer peripheral surface of the first mating section of the central shaft portion, and the texture array is used to drive the liquid metal in the filling cavity to flow.

[0019] Optionally, the texture array includes at least a first texture array and a second texture array, the first texture array and the second texture array are spaced apart in the first mating section along the first direction, each of the texture arrays includes a plurality of guide grooves, and the distance between the first texture array and the second texture array is taken from [20, 40] mm.

[0020] Optionally, the number of the guide grooves of each texture array is set from [50, 100].

[0021] Optionally, each of the guide grooves is in a herringbone shape.

[0022] Optionally, the maximum width of each of the guide grooves is taken from [0.2, 0.7] mm.

[0023] Optionally, the maximum depth of each of the guide grooves is taken from [0.01, 0.1] mm.

[0024] Optionally, a ridge structure is formed between two adjacent guide grooves in each texture array, and an angle between the tips of the ridge structure is set at [55, 60] degrees.

[0025] Optionally, the outer shaft portion is provided with a liquid injection hole connected to the filling cavity, and the liquid injection hole is used to inject the liquid metal into the filling cavity.

[0026] Optionally, the X-ray tube further includes: a rotor, directly or indirectly connected to the outer shaft, and the rotor is used to drive the outer shaft to rotate about the middle shaft.

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

[0028] The technical solution of this application, with the support portion selectively abutting the central shaft portion in response to the outer shaft's rotational speed, effectively reduces direct contact and wear between the central and outer shaft portions during the start-up and shutdown of the X-ray tube. Furthermore, support is provided at low speeds or when stationary, and separation occurs at high speeds, reducing wear caused by contact and increasing the lifespan and stability of the X-ray tube.

[0029] Furthermore, the structure of using an elastic member to push the protrusion out ensures that the protrusion can be extended in time to provide support at low speeds or when the vehicle is stationary. The elastic force of the elastic member ensures reliable contact between the protrusion and the central axis, while at high speeds, this elastic force can be overcome by centrifugal force, causing the elastic member to retract.

[0030] Furthermore, by accommodating the projection and the elastic member in the groove, the groove provides a stable mounting position and movement space for the projection and the elastic member, thereby ensuring smooth and accurate extension and retraction of the projection and avoiding increased wear caused by unstable installation. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic diagram of an X-ray tube according to an embodiment of the present invention;

[0032] Figure 2 yes Figure 1 Schematic diagram of the cooperation between the middle shaft portion and the outer shaft portion;

[0033] Figure 3 yes Figure 1 Schematic diagram of the middle support portion;

[0034] Figure 4 yes Figure 3 A cross-sectional view of the structure shown along the AA direction;

[0035] Figure 5 yes Figure 1 a schematic diagram of the first section of the mid-shaft portion;

[0036] Figure 6 yes Figure 5 A partial enlarged view of the middle area B;

[0037] Figure 7 yes Figure 1 Schematic diagram of the middle and outer shafts;

[0038] Figure 8 yes Figure 1 a schematic diagram of the middle cover portion;

[0039] Figure 9 It is a schematic diagram of the change of relative bearing capacity with the number of slots;

[0040] Figure 10 is a schematic diagram of the relative bearing capacity changing with the groove depth;

[0041] Figure 11 It is a schematic diagram of the change of relative bearing capacity with the angle of the herringbone groove. DETAILED DESCRIPTION

[0042] As mentioned in the background art, the service life of existing X-ray tubes is relatively short.

[0043] To solve the above technical problems, an embodiment of the present invention provides an X-ray tube using a liquid metal bearing, comprising: a housing defining a housing cavity, the housing having a first side and a second side opposite to each other along a first direction; an anode target disposed in the housing cavity; a central axis extending along the first direction and having a first end and a second end opposite to each other, wherein the first end is fixedly connected to the first side; an outer axis connected to the anode target, the outer axis being sleeved on a first mating section of the central axis and rotatable about the central axis, the second end being located in the first mating section, a non-zero first gap being defined between an inner wall of the outer axis and an outer circumferential surface of the first mating section, the first gap forming at least a portion of a filling cavity, the filling cavity being filled with liquid metal, the first mating section, the outer axis, and the liquid metal in the filling cavity cooperating to form a liquid metal bearing; and a support portion sleeved on the central axis, the support portion being fixedly connected to the outer axis portion and rotating synchronously with the outer axis portion, and at least a portion of the support portion selectively abutting against the central axis portion in response to the rotational speed of the outer axis portion.

[0044] The technical solution of this application, in which the support portion selectively abuts the central shaft portion in response to the rotational speed of the outer shaft portion, effectively reduces direct contact and wear between the central and outer shaft portions during the start-up and shutdown of the X-ray tube. Furthermore, support is provided at low speeds or when stationary, and separation occurs at high speeds, reducing wear caused by contact and extending the lifespan and stability of the X-ray tube.

[0045] In order to make the above-mentioned objects, features and beneficial effects of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0046] Figure 1 is a schematic diagram of an X-ray tube 100 according to an embodiment of the present invention. Figure 2 yes Figure 1 Schematic diagram of the cooperation between the middle shaft portion 3 and the outer shaft portion 4.

[0047] Combine Figure 1 and Figure 2The X-ray tube 100 using a liquid metal bearing may include a shell 1, which defines a housing 11, and has a first side 101 and a second side 102 opposite to each other along a first direction D1; an anode target 2, which is arranged in the housing 11; a central axis 3, which extends along the first direction D1 and has a first end 301 and a second end 302 opposite to each other, wherein the first end 301 is fixedly connected to the first side 101; an outer axis 4, which is connected to the anode target 2, and the outer axis 4 is sleeved on the first matching section 31 of the central axis 3 and can rotate with the central axis 3 as the axis, and the second end 302 is located at the central axis. The first fitting section 31, a non-zero first gap G1 is provided between the inner wall of the outer shaft portion 4 and the outer peripheral surface of the first fitting section 31, the first gap G1 forms at least a part of the filling cavity G0, the filling cavity G0 is filled with liquid metal, the first fitting section 31, the outer shaft portion 4 and the liquid metal in the filling cavity G0 cooperate to form a liquid metal bearing; the support portion 5 is sleeved on the middle shaft portion 3, the support portion 5 and the outer shaft portion 4 are fixedly connected and rotate synchronously with the outer shaft portion 4, and at least a part of the support portion 5 selectively resists the middle shaft portion 3 with the rotation speed of the outer shaft portion 4.

[0048] The X-ray tube 100 (also referred to as an X-ray tube or CT tube) can be used in medical X-ray machines, such as CT machines and other disease detection instruments. With technological advancements, CT machines have become increasingly popular due to their high resolution and intuitive, accurate diagnostic capabilities, and are widely used in the medical field. The X-ray tube 100, as a core component in CT machines, is widely used in practice to generate X-rays. Therefore, the technical sophistication of the X-ray tube 100 directly impacts the performance of CT machines.

[0049] In X-ray tube 100, X-rays are generated by the heating of the filament in cathode assembly 9, which generates electrons. These electrons are accelerated by the high-voltage electric field between cathode assembly 9 and anode target 2 to bombard anode target 2, thereby generating X-rays. The X-rays are reflected by the surface of anode target 2, emitted from electron emission window 12, and then received by the CT detector after passing through the patient. The process of electron bombardment of anode target 2 generates a large amount of heat. If the bombardment position remains unchanged, the bombarded area of ​​anode target 2 will generate a large amount of heat, and the heat generation rate is much faster than the heat dissipation rate. When the heat accumulates to a critical value, the bombarded area of ​​the target surface melts, causing the anode to fail. Therefore, in the prior art, X-ray tubes 100 generally use a rotating anode, that is, the anode target 2 is in a rotating state during operation. This allows the position of electron bombardment on anode target 2 to continuously change, preventing local temperature increases from damaging the anode target disk.

[0050] In some embodiments, the housing 1 defines a housing 11 having a first side 101 and a second side 102 opposite to each other along a first direction D1. The housing 11 provides a mounting space for internal components of the tube (e.g., the anode target 2, the middle shaft 3, the outer shaft 4, and the support 5).

[0051] Furthermore, the middle axis portion 3 may extend along the first direction D1 and have a first end 301 and a second end 302 opposite to each other. The first end 301 is fixedly connected to the first side 101 .

[0052] Furthermore, along the extension direction, the middle shaft portion 3 may have a first matching segment 31 and a second matching segment 32 , wherein the second end 302 is located in the first matching segment 31 , and the first matching segment 31 is used to match with the outer shaft portion 4 .

[0053] Further, combined Figure 2 and Figure 7 The outer shaft portion 4 may include a sleeve portion 43 and be formed with an assembly hole 42 extending along the first direction D1. The first fitting section 31 is accommodated in the assembly hole 42.

[0054] Furthermore, a non-zero first gap G1 is provided between the inner wall of the assembly hole 42 and the outer peripheral surface of the first mating section 31, and the first gap G1 forms at least a portion of the filling cavity G0. The filling cavity G0 is filled with liquid metal, and the first mating section 31, the outer shaft portion 4 and the liquid metal in the filling cavity G0 cooperate to form a liquid metal bearing. Thus, the outer shaft portion 4 is connected to the anode target 2, driving the anode target 2 to rotate. The formation of the liquid metal bearing enables the outer shaft portion 4 to rotate smoothly with the middle shaft portion 3 as the axis, and the liquid metal plays a lubricating and supporting role in the gap, reducing friction, improving the smoothness and stability of the rotation, and at the same time being able to withstand the force and heat generated by the anode target 2 during high-speed rotation.

[0055] Furthermore, the support portion 5 is sleeved on the middle shaft portion 3 and fixedly connected to the outer shaft portion 4 .

[0056] In some embodiments, the outer shaft portion 4 may further include a connecting portion 44 formed on a side of the sleeve portion 43 away from the first direction D1 .

[0057] Furthermore, the connecting portion 44 may be disposed around the outer periphery of the sleeve portion 43 to form a ring structure. Furthermore, along the first direction D1 , the area enclosed by the projection of the connecting portion 44 is larger than the area enclosed by the sleeve portion 43 .

[0058] In some embodiments, the supporting portion 5 may be connected to the connecting portion 44 .

[0059] Furthermore, the support portion 5 rotates synchronously with the outer shaft portion 4, playing the role of auxiliary support and stabilization of the outer shaft portion 4. The support portion 5 selectively abuts the middle shaft portion 3 according to the rotation speed of the outer shaft portion 4, and the support strength can be adjusted according to the change in the rotation speed of the outer shaft portion 4, to ensure that the outer shaft portion 4 can operate stably under different working conditions, further enhancing the reliability and stability of the overall structure of the X-ray tube 100. Among them, selective abutment refers to abutment or non-abutment according to the rotation speed of the outer shaft portion 4. Specifically, when the rotation speed of the outer shaft portion 4 is low or not rotating, at least a portion of the support portion 5 abuts the middle shaft portion 3; when the rotation speed of the outer shaft portion 4 is high, the support portion 5 does not abut the middle shaft portion 3, that is, it is separated from the middle peripheral portion 3 and does not form a support.

[0060] In some embodiments, in response to the rotation speed of the outer shaft portion 4 being less than a preset threshold, at least a portion of the support portion 5 abuts against the middle shaft portion 3, and in response to the rotation speed of the outer shaft portion 4 being greater than or equal to the preset threshold, the support portion 5 separates from the middle shaft portion 3.

[0061] Specifically, the support portion 5 supports the middle shaft portion 3 when the outer shaft portion 4 is in a low rotational speed state to ensure that the axis of the middle shaft portion 3 coincides with the axis of the outer shaft portion 4 (or basically coincides within the allowable error range), thereby enabling the outer shaft portion 4 and the anode target 2 connected to the outer shaft portion 4 to rotate stably around the middle shaft portion 3 as the axis.

[0062] When the X-ray tube 100 is just started (or about to be shut down) and is in the low-speed operation stage, the outer shaft portion 4 has relatively poor rotational stability due to its low rotational speed. At this time, the support portion 5 will come into play, supporting the central shaft portion 3. This supporting action can ensure that the axes of the central shaft portion 3 and the outer shaft portion 4 coincide as much as possible. Because at low speeds, the outer shaft portion 4 may produce a certain amount of shaking or deviation due to various factors (such as initial imbalance, slight external interference, etc.), and the support of the support portion 5 can limit this deviation, ensuring that the outer shaft portion 4 can rotate smoothly around the central shaft portion 3, avoiding vibration, noise and other problems caused by axis misalignment, and also providing good initial conditions for subsequent steady-state operation.

[0063] At the same time, when the outer shaft portion 4 enters the working steady state of high-speed operation, the rotation speed of the outer shaft portion 4 reaches the normal working speed, and the support portion 5 is separated from the middle shaft portion 3. Under the action of centrifugal force, the outer shaft portion 4 and the anode target 2 can stably rotate with the middle shaft portion 3 as the axis. At this time, the separation of the support portion 5 and the middle shaft portion 3 can avoid continuous resistance against the middle shaft portion 3 during steady-state operation, which will cause friction between the support portion 5 and the middle shaft portion 3. Long-term friction will cause wear of the middle shaft portion 3, reduce the service life of the middle shaft portion 3, and may also affect the overall performance and accuracy of the tube. Therefore, canceling the resistance during steady-state operation can avoid this unnecessary wear and ensure the efficient and stable operation of the tube.

[0064] In some embodiments, the preset threshold value may be, for example, 10-15 Hz. During steady-state operation, the rotation speed of the anode target 2 is approximately 100-200 Hz.

[0065] In some embodiments, combined Figures 1 to 4 The support portion 5 includes: a ring portion 51, directly or indirectly connected to the end of the outer shaft portion 4 facing the first side 101; a plurality of retractable protrusions 52, spaced around the middle shaft portion 3 and arranged on the inner wall of the ring portion 51 facing the middle shaft portion 3, and the protrusions 52 can extend toward the middle shaft portion 3 to support the middle shaft portion 3 or retract in a direction away from the middle shaft portion 3 to separate from the middle shaft portion 3.

[0066] Specifically, the ring portion 51 serves as the main structure of the support portion 5 and provides a mounting location for the protrusion 52. The connection between the ring portion 51 and the outer shaft portion 4 enables the support portion 5 to rotate synchronously with the outer shaft portion 4. In some embodiments, the connection between the ring portion 51 and the outer shaft portion 4 can be direct, for example, by fixing the ring portion 51 and the end of the outer shaft portion 4 together through welding, threaded connection, bolt and nut connection, etc.; or it can be indirect, such as connecting the ring portion 51 and the outer shaft portion 4 through an intermediate connector. In this way, the support portion 5 and the outer shaft portion 4 can be firmly connected, thereby ensuring that the support portion 5 can accurately follow the outer shaft portion 4 in synchronous movement.

[0067] Furthermore, a plurality of retractable protrusions 52 are spaced around the central axis 3 and arranged on the inner wall of the ring portion 51 facing the central axis 3. This ensures that the protrusions 52 can evenly distribute the force when abutting against the central axis 3, thus avoiding damage to the central axis 3 or the protrusions 52 due to excessive local force.

[0068] Furthermore, when the X-ray tube 100 is just starting up (or about to shut down) and operating at a low speed, the protrusion 52 will extend toward the central axis 3 and abut against the central axis 3. This ensures that the axes of the central axis 3 and the outer axis 4 coincide with each other, improves the rotational stability of the outer axis 4, reduces vibration and noise, and ensures that the X-ray tube 100 can operate smoothly during startup and shutdown.

[0069] Furthermore, when the X-ray tube 100 enters a steady-state operation phase, the protrusion 52 retracts away from the central axis 3 and separates from the central axis 3. This prevents friction between the protrusion 52 and the central axis 3, preventing the central axis 3 from wearing out due to long-term friction, and thus extending the service life of the central axis 3.

[0070] As shown above, the ring portion 51 of the support portion 5 and the retractable protrusion 52 cooperate with each other, and the retractability of the protrusion 52 realizes the selective support function of the central axis portion 3, which not only ensures the stable operation of the X-ray tube 100 under different working conditions, but also avoids unnecessary wear and tear, thereby improving the reliability and service life of the X-ray tube 100.

[0071] In some embodiments, the support portion 5 further includes a plurality of elastic members 53 , and the plurality of elastic members 53 correspond one-to-one to the plurality of protrusions 52 . The elastic members 53 are used to push the corresponding protrusions 52 toward the central axis portion 3 .

[0072] It should be understood that the multiple elastic members 53 herein may be independent components, or may be different parts of an integral elastic component.

[0073] In some embodiments, when the X-ray tube 100 is in the start-up and stop phases and the rotation speed is low, the protrusion 52 needs to extend to abut against the middle shaft 3 to ensure the rotation stability of the outer shaft 4. At this time, the elastic member 53 applies an elastic force to the protrusion 52 toward the middle shaft 3.

[0074] Furthermore, the elastic member 53 continuously applies elastic force to the projection 52, so that the projection 52 can maintain a stable pressure when abutting the central shaft portion 3. This stable pressure ensures that the axes of the central shaft portion 3 and the outer shaft portion 4 always remain well aligned. Even if the X-ray tube 100 is subject to slight external disturbances during operation, the elastic force of the elastic member 53 can adjust the abutting force of the projection 52, thereby ensuring the rotational stability of the outer shaft portion 4.

[0075] In some embodiments, the inner wall of the ring portion 51 facing the central axis portion 3 is provided with a plurality of grooves 54, each of which corresponds to the plurality of retractable protrusions 52. At least a portion of each protrusion 52 and the corresponding elastic member 53 are accommodated in the corresponding groove 54. The protrusion 52 can be extended or retracted into the corresponding groove 54 under the push of the corresponding elastic member 53. Thus, the grooves 54 provide mounting locations for the protrusions 52 and the elastic member 53, allowing the protrusions 52 and the elastic member 53 to be stably mounted on the ring portion 51.

[0076] Furthermore, the groove 54 provides a track for the extension and retraction of the projection 52. Under the push of the corresponding elastic member 53, the projection 52 can extend or retract along the direction of the groove 54. This makes the movement of the projection 52 smoother and more orderly, avoiding problems such as jamming and offsetting of the projection 52 during movement, and ensuring that the projection 52 can accurately extend to abut the central axis 3 or retract to separate from the central axis 3.

[0077] Furthermore, as the rotation speed of the outer shaft portion 4 increases, the protrusion 52 retracts into the groove portion 54 in a direction away from the middle shaft portion 3 under the action of centrifugal force and compresses the elastic member 53 .

[0078] In actual application, when the outer shaft 4 starts to rotate, the protrusion 52, because it is fixed to the ring portion 51 (the ring portion 51 is connected to the outer shaft 4), will make a circular motion along with the outer shaft 4. As the speed of the outer shaft 4 increases, the centrifugal force on the protrusion 52 increases accordingly.

[0079] Taking the startup process of the X-ray tube 100 as an example, in the initial stage, the elastic member 53 exerts a spring force on the protrusion 52, pushing it outward toward the central axis 3 to achieve its function of abutting the central axis 3. When the speed of the outer shaft 4 increases to a certain level, the centrifugal force gradually increases. When the centrifugal force becomes greater than the spring force exerted by the elastic member 53 on the protrusion 52, the protrusion 52 overcomes the spring force of the elastic member under the action of the centrifugal force and moves away from the central axis 3. Furthermore, during the retraction process, the protrusion 52 exerts a squeezing effect on the elastic member 53, compressing it. During this compression, the elastic member 53 stores elastic potential energy. When the speed of the outer shaft 4 decreases (e.g., when the machine is about to shut down), the elastic member 53 releases this stored elastic potential energy, pushing the protrusion 52 outward toward the central axis 3 again.

[0080] In some embodiments, combined Figure 1 and Figure 2 A non-zero second gap G2 exists between the ring portion 51 and the central shaft portion 3 , forming part of the filling cavity G0 . Because the second gap G2 is part of the filling cavity G0 and the filling cavity G0 is filled with liquid metal, the liquid metal can form a holistic support structure within the filling cavity G0 . Furthermore, the presence of the second gap G2 allows the liquid metal to be more evenly distributed between the ring portion 51 and the central shaft portion 3 , thereby more evenly bearing and supporting the weight and rotational force of the outer shaft portion 4 during rotation.

[0081] In addition, liquid metal has a certain heat conduction capability. The second gap G2, as part of the filling cavity G0, allows the liquid metal to more widely contact the ring portion 51 and the central shaft portion 3, thereby more effectively transferring heat from the anode target 2 and the outer shaft portion 4 to the central shaft portion 3.

[0082] Furthermore, the central axis portion 3 may have a hollow structure, which may be in the form of a blind hole. Furthermore, an opening of the hollow structure is formed at the first end 301 and communicates with the exterior of the housing 1. Furthermore, the interior of the hollow structure may be filled with a cooling medium to improve the overall heat dissipation of the X-ray tube 100.

[0083] In some embodiments, the ring portion 51 is sleeved on the second fitting segment 32 of the middle shaft portion 3, the cross-sectional area of ​​the second fitting segment 32 is larger than the cross-sectional area of ​​the first fitting segment 31, and along the first direction D1, there is a non-zero third gap G3 between the outer shaft portion 4 and the second fitting segment 32, the third gap G3 connects the first gap G1 and the second gap G2, and the third gap G3 forms a part of the filling cavity G0.

[0084] Furthermore, along direction D1, the outer shaft portion 4 can be supported on the end surface of the second mating segment 32 facing the first direction D1 by liquid metal in the third gap G3. Furthermore, the third gap G3 connects the first gap G1 with the second gap G2. As a result, liquid metal fills the spaces between the first mating segment 31 and the sleeve portion 43, between the second mating segment 32 and the connecting portion 44, and between the second mating segment 32 and the ring portion 51. This prevents wear between the outer shaft portion 4 and the ring portion 51 and the central shaft portion 3 during high-speed operation, which could affect the service life of the X-ray tube 100.

[0085] Furthermore, the second fitting section 32 with a larger cross-sectional area can also provide a larger outer peripheral surface. Thus, the support portion 5 can be configured with more retractable protrusions 52 to more stably support the central axis portion 3 during the startup or shutdown phase or low-speed operation phase of the X-ray tube 100.

[0086] Further, combined Figure 2 and Figure 7 A texture array 6 is provided in the first area of ​​the end surface of the outer shaft portion 4 facing the first side 101. Along the first direction D1, the projection of the second mating segment 32 coincides with the first area. The texture array 6 is used to drive the flow of the liquid metal in the filling cavity G0. Each texture array 6 includes a plurality of guide grooves 60.

[0087] During the operation of the X-ray tube 100, the filling cavity G0 is filled with liquid metal. By setting the texture array 6, the flow state of the liquid metal can be changed, and the liquid metal can be promoted to circulate more effectively in the filling cavity G0, thereby improving the heat dissipation efficiency and ensuring the performance and life of the X-ray tube 100.

[0088] Furthermore, the first region is formed on a surface of the connecting portion 44 that faces the opposite direction to the first direction D1 . Furthermore, the first region surrounds the opening of the assembly hole 42 .

[0089] Furthermore, each texture array 6 includes a plurality of guide grooves 60 . The guide grooves 60 are basic components of the texture array 6 .

[0090] In practical applications, different guide groove 60 shapes (e.g., linear, wavy, spiral, etc.) and arrangements (e.g., parallel, cross-shaped, etc.) can produce different liquid metal flow patterns. For example, wavy guide grooves 60 can create disturbances in the liquid metal during flow, enhancing heat exchange between the liquid metal and the surrounding environment; spiral guide grooves 60 can guide the liquid metal into a spiral flow, increasing the flow distance and circulation speed of the liquid metal within the filling cavity G0.

[0091] In some embodiments, combined Figure 2 and Figure 8 The X-ray tube 100 may further include a cover portion 7 having a central through hole 74 extending along the first direction D1. The cover portion 7 is sleeved on the central axis portion 3 and closes the opening of the filling cavity G0 toward the first side 101. The cover portion 7 is fixedly connected to the ring portion 51. The cover portion 7, the ring portion 51 and the outer axis portion 4 rotate synchronously.

[0092] Specifically, the shape and size of the central through hole 74 can be designed according to the shape and size of the central shaft portion 3 to ensure that the central shaft portion 3 can pass through the through hole smoothly.

[0093] Furthermore, the cover portion 7 and the support portion 5 are fixedly connected and rotate along with the rotation of the outer shaft portion 4. Furthermore, along the first direction D1, the second matching section 32 is clamped between the outer shaft portion 4 and the cover portion 7.

[0094] Furthermore, the cover portion 7 includes a sealing flange portion 71 and a sleeve portion 72 connected along the first direction D1. The sealing flange portion 71 is closer to the second side 102 than the sleeve portion 72. A non-zero fourth gap G4 exists between the sealing flange portion 71 and the central axis portion 3, forming a portion of the filling cavity G0. The sleeve portion 72 defines at least one overflow prevention groove 73 on the inner wall of the central axis portion 3. Thus, the fourth gap G4 between the sealing flange portion 71 and the central axis portion 3 is also filled with liquid metal, ensuring that the cover portion 7 can smoothly rotate around the central axis portion 3 and preventing wear or wear of the components.

[0095] Furthermore, at least one overflow prevention groove 73 is formed on the inner wall of the sleeve portion 72 facing the central axis portion 3. The overflow prevention groove 73 can be used to prevent the liquid metal filled in the filling cavity G0 from overflowing from the gap between the sleeve portion 72 and the central axis portion 3.

[0096] In some embodiments, the number of the anti-overflow grooves 73 may be two.

[0097] In some embodiments, a texture array 6 is provided on a second region of the end surface of the cover portion 7 facing the second mating segment 32. The projection of the second mating segment 32 along the first direction D1 overlaps with the second region. The texture array 6 is used to drive the flow of the liquid metal within the filling cavity G0. Each texture array 6 includes a plurality of guide grooves 60. Thus, by designing the second mating segment 32 of the central axis portion 3 and the texture array 6 of the cover portion 7 (including the plurality of guide grooves 60), effective drive of the liquid metal flow within the filling cavity G0 is achieved, thereby improving the heat dissipation performance and overall stability of the X-ray tube 100, thereby extending the service life of the X-ray tube 100 and enhancing its operational reliability.

[0098] In some embodiments, combined Figure 2 and Figure 7 The outer circumference of the first mating section 31 of the central shaft portion 3 is provided with a texture array 6, which is used to drive the liquid metal within the filling cavity G0. Thus, under the combined action of the texture array 6 of the first mating section 31 and the texture array 6 of the cover portion 7, when the outer shaft portion 4, the cover portion 7, and the supporting portion 5 therebetween rotate at high speed around the central shaft portion 3, the liquid metal is more evenly distributed in the second gap G2, the third gap G3, and the fourth gap G4, thereby ensuring smoother operation of the X-ray tube 100.

[0099] In some embodiments, combined Figure 2 and Figure 5 The texture array 6 includes at least a first texture array 61 and a second texture array 62. The first texture array 61 and the second texture array 62 are spaced apart in the first matching section 31 along the first direction D1. Each of the texture arrays 6 includes a plurality of guide grooves 60. The distance between the first texture array 61 and the second texture array 62 is in the range of [20, 40] mm.

[0100] In some embodiments, the middle shaft portion 3 may include a first section 303 and a second section 304 that are detachably connected, wherein the second end 302 , the first fitting section 31 and the second fitting section 32 are all located in the first section 303 .

[0101] In some embodiments, the liquid metal may be a liquid metal alloy of InGaSn material.

[0102] In some embodiments, a coating structure may be provided on the surfaces of the middle shaft portion 3, the outer shaft portion 4 and the cover portion 7 that are in contact with or close to each other. The coating structure may be, for example, a molybdenum disulfide layer to enhance the wear resistance of each component and extend the service life of the X-ray tube 100.

[0103] In some embodiments, the number of the guide grooves 60 of each of the texture arrays 6 is set to a value between [50, 100].

[0104] In some embodiments, reference Figure 5 and Figure 6 Each of the guide grooves 60 is in a herringbone shape.

[0105] In some embodiments, the maximum width of each of the guide grooves 60 is in the range of [0.2, 0.7] mm.

[0106] In some embodiments, the maximum depth of each of the guide grooves 60 is set to [0.01, 0.1] mm.

[0107] In some embodiments, a ridge structure is formed between two adjacent guide grooves 60 in each texture array 6 , and the angle between the tips of the ridge structure is in the range of [55, 60] degrees.

[0108] In order to verify the optimality of the above parameters of the guide grooves 60, the inventors conducted simulation experiments to verify the effects of the number of grooves (the number of guide grooves 60), the groove depth (the depth of the guide grooves 60), and the herringbone groove angle (the angle between the tips of the ridge structure formed between two adjacent guide grooves 60) on the relative bearing capacity. The results of the simulation experiments can be referred to Figures 9 to 11 .

[0109] Liquid metal bearings are a type of sliding bearing. Due to the misalignment of the bearing (i.e., the first mating section 31 in this application) and the sleeve (i.e., the sleeve portion 43 in this application) within this type of bearing, there is an eccentric distance, denoted as e, due to the load. The eccentricity ε is defined as follows:

[0110]

[0111] Where c is the radial clearance of the bearing, i.e. half of the difference between the diameter of the first fitting section 31 and the inner diameter of the sleeve portion 43;

[0112] Relative load capacity is an indicator that non-dimensionalizes factors such as actual load capacity, lubrication conditions, and bearing size, making data under different conditions easier to compare and analyze. Relative load capacity S is defined as:

[0113]

[0114] Where W is the bearing load, in Newton (N); P is the average unit pressure, in Pa; l and d are the length of the mutually nested portion of the first fitting section 31 and the sleeve portion 43 and the outer diameter of the first fitting section 31, respectively.

[0115] According to experimental results, taking into account the difficulty of processing, the number of guide grooves 60 is set to [50, 100], the maximum depth of the guide grooves 60 is set to [0.01, 0.1] mm, a ridge structure is formed between two adjacent guide grooves 60, and the angle of the tip of the ridge structure is set to [55, 60] degrees, which can take into account both economic benefits and the stability of the operation of the X-ray tube 100.

[0116] In some embodiments, the interface shape of the guide groove 60 can be rectangular, V-shaped, or arc-shaped.

[0117] In some embodiments, combined Figure 1 and Figure 2 The outer shaft portion 4 is provided with a liquid injection hole 41 connected to the filling cavity G0, and the liquid injection hole 41 is used to inject the liquid metal into the filling cavity G0.

[0118] In some embodiments, the X-ray tube 100 may further include: a rotor 8 directly or indirectly connected to the outer shaft 4 , and the rotor 8 is used to drive the outer shaft 4 to rotate around the middle shaft 3 .

[0119] As described above, the technical solution of this application, with the support portion 5 selectively abutting the central shaft portion 3 in accordance with the rotational speed of the outer shaft portion 4, can effectively reduce direct contact and wear between the central shaft portion 3 and the outer shaft portion 4 during the start-up and shutdown of the X-ray tube 100. Furthermore, support is provided at low speeds or when stationary, and separation occurs at high speeds, reducing wear caused by contact and improving the service life and stability of the X-ray tube 100.

[0120] Furthermore, the structure in which the elastic member 53 pushes the protrusion 52 outward ensures that the protrusion 52 can be extended in time to provide support at low speeds or when the vehicle is stationary. The elastic force of the elastic member 53 ensures that the protrusion 52 is in reliable contact with the central axis portion 3, while the centrifugal force can overcome it and retract it at high speeds.

[0121] Furthermore, by accommodating the projection 52 and the elastic member 53 in the groove 54, the groove 54 provides a stable mounting position and movement space for the projection 52 and the elastic member 53. This ensures smooth and accurate extension and retraction of the projection 52, and avoids increased wear caused by unstable installation.

[0122] It should be understood that the term "and / or" herein is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent three situations: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " herein indicates that the objects associated before and after are in an "or" relationship. As used herein, unless otherwise expressly stated, the term "or" covers all possible combinations unless not feasible. For example, if a component is stated to include A or B, then unless otherwise expressly stated or not feasible, the component may include A, or B, or A and B. As a second example, if a component is stated to include A, B, or C, then unless otherwise expressly stated or not feasible, the component may include A, or B, or C, or A and B, or A and C, or B and C, or A and B and C.

[0123] The term “plurality” used in the embodiments of the present invention refers to two or more than two.

[0124] Relational terms appearing in the embodiments of the present invention, such as first, second, etc. descriptions, are only used to distinguish an entity or operation from another entity or operation, and do not require or imply any actual relationship or order between these entities or operations. In addition, the words "include", "have" and "comprise" and other similar forms are intended to be equivalent in meaning and are open-ended, and one or more items following any of these words do not mean an exhaustive list of such one or more items, or mean to be limited to the one or more items listed. In the drawings and description, exemplary embodiments have been disclosed. However, many variations and modifications can be made to these embodiments. Therefore, although specific terms are used, they are used only in a general and descriptive sense, and not for the purpose of limitation.

[0125] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. An X-ray tube using a liquid metal bearing, characterized in that: include: A housing defines a receiving cavity, wherein the housing has a first side and a second side opposite to each other along a first direction; an anode target, disposed in the accommodating cavity; a middle shaft portion extending along the first direction and having a first end and a second end opposite to each other, wherein the first end is fixedly connected to the first side; an outer shaft portion connected to the anode target, the outer shaft portion being sleeved on the first mating section of the middle shaft portion and rotatable with the middle shaft portion as an axis, the second end being located in the first mating section, a non-zero first gap being defined between an inner wall of the outer shaft portion and an outer circumferential surface of the first mating section, the first gap forming at least a portion of a filling cavity filled with liquid metal, the first mating section, the outer shaft portion, and the liquid metal in the filling cavity cooperating to form a liquid metal bearing; The support portion is sleeved on the middle shaft portion, the support portion is fixedly connected to the outer shaft portion and rotates synchronously with the outer shaft portion, and at least a portion of the support portion selectively abuts against the middle shaft portion according to the rotation speed of the outer shaft portion; wherein The support portion includes: a ring portion, directly or indirectly connected to the end portion of the outer shaft portion facing the first side; a plurality of retractable protrusions, spaced around the central axis and disposed on an inner wall of the ring portion facing the central axis, the protrusions being capable of extending toward the central axis to abut against the central axis or retracting away from the central axis to separate from the central axis; The support portion further includes a plurality of elastic members, each of the elastic members corresponding to the plurality of protrusions, and the elastic members are used to push the corresponding protrusions to extend toward the central axis portion; A plurality of grooves are formed on the inner wall of the ring portion facing the central axis portion; As the rotation speed of the outer shaft portion increases, the protrusion retracts into the groove portion in a direction away from the middle shaft portion under the action of centrifugal force and compresses the elastic member.

2. The X-ray tube according to claim 1, characterized in that In response to the rotation speed of the outer shaft being less than a preset threshold, at least a portion of the support portion abuts against the middle shaft portion. In response to the rotation speed of the outer shaft being greater than or equal to the preset threshold, the support portion separates from the middle shaft portion.

3. The X-ray tube according to claim 1, wherein: The multiple grooves correspond to the multiple retractable protrusions one by one, at least a portion of each protrusion and the corresponding elastic member are accommodated in the corresponding groove, and the protrusion can extend or retract into the corresponding groove under the push of the corresponding elastic member.

4. The X-ray tube according to claim 1, wherein: A non-zero second gap exists between the ring portion and the central shaft portion, and the second gap forms a part of the filling cavity.

5. The X-ray tube according to claim 4, characterized in that: The ring portion is sleeved on the second fitting section of the middle shaft portion, the cross-sectional area of ​​the second fitting section is larger than the cross-sectional area of ​​the first fitting section, and along the first direction, a non-zero third gap exists between the outer shaft portion and the second fitting section, the third gap connects the first gap and the second gap, and the third gap forms a part of the filling cavity.

6. The X-ray tube according to claim 5, characterized in that A texture array is provided in the first area of ​​the end surface of the outer shaft portion facing the first side. Along the first direction, the projection of the second mating segment coincides with the first area. The texture array is used to drive the flow of the liquid metal in the filling cavity. Each texture array includes a plurality of guide grooves.

7. The X-ray tube according to claim 1, characterized in that Also includes: The covering portion has a central through hole extending along the first direction. The covering portion is sleeved on the central axis portion and closes the opening of the filling cavity toward the first side. The covering portion and the ring portion are fixedly connected. The covering portion, the ring portion and the outer axis portion rotate synchronously.

8. The X-ray tube according to claim 7, characterized in that The sealing cover portion includes a sealing flange portion and a sleeve portion connected along the first direction, wherein the sealing flange portion is closer to the second side than the sleeve portion, and there is a non-zero fourth gap between the sealing flange portion and the central axis portion, and the fourth gap forms a part of the filling cavity; the sleeve portion is provided with at least one anti-overflow groove on the inner wall facing the central axis portion.

9. The X-ray tube according to claim 7, characterized in that The middle shaft portion includes a second mating segment, the cross-sectional area of ​​the second mating segment is larger than the cross-sectional area of ​​the first mating segment, and along the first direction, the second mating segment is located between the outer shaft portion and the cover portion, and a texture array is provided in a second area of ​​the end surface of the cover portion facing the second mating segment, and a projection of the second mating segment along the first direction coincides with the second area, and the texture array is used to drive the flow of the liquid metal in the filling cavity, and each texture array includes a plurality of guide grooves.

10. The X-ray tube according to claim 1, wherein: A texture array is provided on the outer peripheral surface of the first matching section of the central shaft portion, and the texture array is used to drive the liquid metal in the filling cavity to flow.

11. The X-ray tube according to claim 10, characterized in that: The texture array includes at least a first texture array and a second texture array, the first texture array and the second texture array are arranged at intervals in the first matching section along the first direction, each of the texture arrays includes a plurality of guide grooves, and the distance between the first texture array and the second texture array is taken from [20, 40] mm.

12. The X-ray tube according to claim 6, 9 or 11, characterized in that: The number of the guide grooves of each texture array is set to [50, 100]; and / or Each of the guide grooves is in a herringbone shape; and / or The maximum width of each of the guide grooves is in the range of [0.2, 0.7] mm; and / or The maximum depth of each of the guide grooves is [0.01, 0.1] mm; and / or A ridge structure is formed between two adjacent guide grooves in each texture array, and the angle of the tip of the ridge structure is set at [55, 60] degrees.

13. The X-ray tube according to claim 1, wherein The outer shaft portion is provided with a liquid injection hole connected to the filling cavity, and the liquid injection hole is used to inject the liquid metal into the filling cavity.

14. The X-ray tube according to claim 1, wherein Also includes: The rotor is directly or indirectly connected to the outer shaft portion, and is used to drive the outer shaft portion to rotate around the middle shaft portion.

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