Elastic foil type liquid metal bearing suitable for X-ray tube and CT bulb tube

Abstract

The utility model relates to the technical field of X-ray tubes, and provides an elastic foil type liquid metal bearing suitable for an X-ray tube and a CT bulb tube. The bearing sleeve is rotatably arranged on the shaft body part in a sleeving manner and is indirectly matched with one end face of the thrust plate in a stopping manner; the sealing cover is provided with a central through hole, the sealing cover is arranged on the shaft body part in a clearance sleeving mode and connected to the open end of the bearing sleeve in a sealing mode, the sealing cover is indirectly matched with the other end face of the thrust plate in a stopping mode, and a shaft sealing clearance is formed between the inner circumferential wall of the sealing cover and the outer circumferential wall of the shaft body part; the bearing system comprises a radial foil bearing, a first thrust foil bearing and a second thrust foil bearing; wherein liquid film gaps exist between the bearing sleeve and the shaft body part and between the bearing sleeve and the thrust plate, liquid film gaps exist between the sealing cover and the thrust plate, and the liquid film gaps are used for being filled with liquid metal. According to the utility model, the high-speed rotation stability and the anti-vibration performance of the rotating anode assembly can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of X-ray tubes, in particular to an elastic foil type liquid metal bearing suitable for X-ray tubes and a CT tube. Background Art

[0002] X-ray tubes are key components of medical equipment such as X-ray machines and CT machines. Under the action of external high voltage, they can generate radiation such as X-rays. When an object is placed between the X-ray tube and the detector, the radiation will pass through the object and hit the detector. Since the internal structure of the object will affect the spatial variation of the radiation, the detector receives the radiation change signal and can convert the radiation change into image information through the system. The image information can be used to evaluate the internal structure of the object, which can be either a living object or an inanimate object.

[0003] The X-ray tube includes a cathode and an anode in a high vacuum sealed environment. Under the action of high voltage, the electrons generated by the cathode filament of the X-ray tube are accelerated to bombard the anode target disk, thereby generating X-rays. In this process, only 1% of the electron kinetic energy is converted into X-rays, and the remaining 99% of the energy is converted into heat. Therefore, the temperature in the electron bombardment area can even reach 2600℃~2700℃. In order to improve heat dissipation, the high-speed rotating anode target disk can effectively disperse the heat accumulation at the focal position. The rotating anode assembly needs to be supported by a bearing shaft and a target disk and rotated by an induction motor. With the requirements of high-end medical X-ray imaging systems for higher power and faster speed, the requirements for traditional ball bearings are extremely strict. Liquid metal bearings have the advantages of high load capacity, high heat conduction capacity, almost frictionless rotation process, and no noise. It is currently the main method to replace ball bearings. Liquid metal bearings inject gallium or gallium-based alloy liquid metal into the micron-level gap between the bearing rod and the bearing sleeve to replace traditional balls.

[0004] At present, the liquid metal lubricated hydrodynamic sliding bearings used in CT tubes are all spiral groove hydrodynamic bearings, that is, a spiral groove is engraved on the surface of one side of the bearing mating pair to provide pumping effect and hydrodynamic effect for the bearing. For example, the existing patent document (application number: CN202321213751.2) discloses a liquid fluid hydrodynamic sliding bearing for X-ray tube core, on which a circumferential groove is processed by laser etching or cladding, and a first circumferential groove and a second circumferential groove can be set. However, when the frame of the CT machine is in high-speed rotation, due to the small running clearance of the spiral groove hydrodynamic bearing itself, the time-varying centrifugal force (referring to the centrifugal force that changes with time) on the CT tube will be relatively large, and the amplitude of the rotating system of the CT tube will also be relatively large, which will pose a greater challenge to the performance of the spiral groove hydrodynamic bearing, increase the wear degree of the spiral groove hydrodynamic bearing, and shorten the service life of the spiral groove hydrodynamic bearing.

[0005] The existing patent document (application number: US08163148) discloses an annular tube X-ray source with an active vacuum pump. Although its specification describes: "Although a mechanical roller bearing is shown, journal bearings, foil bearings, fluid dynamic bearings, etc. can also be considered", the specific structure and arrangement of the foil bearing are not disclosed. Utility Model Content

[0006] In view of the above-mentioned shortcomings of the prior art, the technical problem to be solved by the present invention is to provide an elastic foil type liquid metal bearing and a CT tube suitable for an X-ray tube, which can improve the high-speed rotation stability and vibration resistance of a rotating anode assembly.

[0007] In order to solve the above technical problems, the utility model provides an elastic foil type liquid metal bearing suitable for an X-ray tube, wherein the elastic foil type liquid metal bearing is arranged in a vacuum tube shell of the X-ray tube, and the elastic foil type liquid metal bearing comprises:

[0008] The central axis of the stator is formed, and the central axis includes a shaft body portion, and a thrust plate is provided on the outer peripheral wall of the shaft body portion;

[0009] The bearing sleeve is used for coaxially connecting the rotating anode of the X-ray tube, and has a sleeve cavity with a single-side opening. The bearing sleeve is rotatably sleeved on the shaft body and indirectly stops with one end surface of the thrust plate;

[0010] A cover having a central through hole, the cover gap is sleeved on the shaft body and is sealed to the open end of the bearing sleeve, the cover is indirectly stopped with the other end face of the thrust plate, the bearing sleeve and the cover jointly axially constrain the thrust plate, and a shaft seal gap is formed between the inner peripheral wall of the cover and the outer peripheral wall of the shaft body;

[0011] The bearing system includes a radial foil bearing, a first thrust foil bearing and a second thrust foil bearing, wherein the radial foil bearing is arranged between the inner peripheral wall of the bearing sleeve and the outer peripheral wall of the shaft body, the first thrust foil bearing is arranged between the opening end of the bearing sleeve and one end face of the thrust plate, and the second thrust foil bearing is arranged between the other end face of the thrust plate and the cover;

[0012] There are liquid film gaps between the bearing sleeve and the shaft body and the thrust plate respectively, and there is a liquid film gap between the cover and the thrust plate, and the liquid film gap is used to fill liquid metal.

[0013] Furthermore, the elastic foil type liquid metal bearing suitable for the X-ray tube also includes a cylindrical rotor, and the rotor is coaxially fixed to the cover.

[0014] Furthermore, the elastic foil type liquid metal bearing suitable for X-ray tubes also includes a sealing ring, which is sealed and connected to the bearing sleeve and the cover respectively, and the sealing ring gap is sleeved on the thrust plate, and a liquid film gap exists between the sealing ring and the thrust plate.

[0015] Furthermore, the sealing cover comprises a sealing flange portion and a shaft sealing sleeve portion integrally formed with the sealing flange portion, and the second thrust foil bearing is arranged between the sealing flange portion and the thrust plate.

[0016] Furthermore, an anti-overflow groove is provided on the inner peripheral wall of the shaft sealing sleeve.

[0017] Furthermore, the bearing sleeve is in a cap shape, and includes a cap body and a brim portion integrally formed with the cap body, and the first thrust foil bearing is arranged between the brim portion and the thrust plate.

[0018] Furthermore, the radial foil bearing comprises a flat foil ring outermostly arranged on the shaft body and a corrugated foil ring outermostly arranged on the flat foil ring.

[0019] Furthermore, the first thrust foil bearing comprises a plurality of first flat foils and a plurality of first corrugated foils, all the first flat foils correspond to all the first corrugated foils one by one, and the first corrugated foils are located on a side of the first flat foil facing away from the thrust plate.

[0020] Furthermore, the first thrust foil bearing and the second thrust foil bearing have the same structure.

[0021] The utility model also provides a CT tube, comprising:

[0022] A vacuum tube shell, wherein a tube cavity of the vacuum tube shell forms a vacuum environment;

[0023] A cathode insulating end sealing assembly, which is arranged at one end of the vacuum tube shell;

[0024] A cathode assembly, which is disposed on the cathode insulating end sealing assembly and is located in the tube cavity;

[0025] An anode insulating end sealing assembly, the anode insulating end sealing assembly is arranged at the other end of the vacuum tube shell;

[0026] The rotary anode assembly comprises a rotary anode and the elastic foil type liquid metal bearing suitable for an X-ray tube, wherein the rotary anode is detachably connected to a bearing sleeve of the elastic foil type liquid metal bearing.

[0027] As described above, the elastic foil type liquid metal bearing and CT tube of the utility model applicable to X-ray tubes have the following beneficial effects: a thrust plate is provided on the outer peripheral wall of the shaft body, and the bearing sleeve and the cover jointly axially constrain the thrust plate. With such a configuration, the bearing sleeve will not axially move relative to the central axis, thereby facilitating the stable high-speed rotation of the rotating anode. More importantly, an elastic foil is used between the bearing sleeve and the central axis and between the cover and the central axis to provide additional Coulomb friction damping to improve the stability and anti-seismic performance of the elastic foil type liquid metal bearing, and liquid metal is filled between the bearing sleeve and the central axis and between the cover and the central axis as a lubricating medium to further improve the rotation speed of the rotating anode and the bearing capacity of the elastic foil type liquid metal bearing. Specifically, the radial foil bearing, the first thrust foil bearing and the second thrust foil bearing provide additional Coulomb friction damping for the elastic foil type liquid metal bearing: the radial foil bearing can bear the static and dynamic loads in the radial direction of the shaft system; the first thrust foil bearing and the second thrust foil bearing can bear the static and dynamic loads in the axial direction of the shaft system. Therefore, the elastic foil type liquid metal bearing of the utility model can improve the high-speed rotation stability and vibration resistance of the rotating anode assembly, and can ensure the stable operation of the CT tube at a higher rotation and revolution speed, thereby improving the shooting performance and service life of the CT machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A three-dimensional diagram showing an elastic foil type liquid metal bearing suitable for an X-ray tube according to the utility model;

[0029] Figure 2 A cross-sectional view of an elastic foil type liquid metal bearing suitable for an X-ray tube according to the utility model is shown;

[0030] Figure 3 The internal structure diagram of the elastic foil type liquid metal bearing suitable for an X-ray tube of the utility model is shown;

[0031] Figure 4 Shown is a perspective view of a radial foil bearing;

[0032] Figure 5 Shown is a perspective view of a first thrust foil bearing;

[0033] Figure 6 Shown is a perspective view of the second thrust foil bearing.

[0034] Explanation of component numbers: center shaft 1, shaft body 11, thrust plate 12, bearing sleeve 2, cap body 21, cap brim 22, cover 3, sealing flange 31, shaft seal sleeve 32, anti-overflow groove 33, bearing system 4, radial foil bearing 41, flat foil ring 411, flat foil ring 412, first thrust foil bearing 42, first flat foil 421, first wave foil 422, second thrust foil bearing 43, rotor 5, rotating anode 6, sealing ring 7. DETAILED DESCRIPTION

[0035] The following is a description of the implementation of the present invention by means of specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0036] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the utility model, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effects and purposes that can be achieved by the utility model, should still fall within the scope of the technical content disclosed by the utility model. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the utility model. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the utility model without substantial change of the technical content.

[0037] The utility model provides a CT tube (the overall structure of the CT tube is not shown in the figure), the CT tube is an X-ray tube, and the CT tube comprises:

[0038] A vacuum tube shell, wherein a tube cavity of the vacuum tube shell forms a vacuum environment;

[0039] A cathode insulating end sealing assembly, which is arranged at one end of the vacuum tube shell;

[0040] A cathode assembly, which is arranged on the cathode insulating end sealing assembly and is located in the tube cavity, and is used to emit an electron beam;

[0041] An anode insulating end sealing assembly, the anode insulating end sealing assembly is arranged at the other end of the vacuum tube shell;

[0042] Rotating anode assembly (see Figures 1 to 6), the rotating anode assembly includes a rotating anode 6 and an elastic foil type liquid metal bearing suitable for an X-ray tube, and the rotating anode 6 is detachably connected to a bearing sleeve 2 of the elastic foil type liquid metal bearing. The rotating anode 6 is used to be bombarded by an electron beam to generate X-rays, and the elastic foil type liquid metal bearing is used to achieve high-speed rotation of the rotating anode 6 relative to the anode insulation end seal assembly.

[0043] In the rotating anode assembly, the rotating anode 6 is an existing structure and will not be described in detail here; the main innovation of the utility model lies in the elastic foil type liquid metal bearing suitable for the X-ray tube, which can improve its own bearing capacity and reduce the requirements for shaft system processing and matching accuracy on the one hand; on the other hand, it provides additional Coulomb friction damping for the rotating anode assembly, improves the rotation speed and bearing capacity of its own structure, so that the CT machine has a higher rotation speed, thereby improving the CT shooting resolution and also improving the vibration resistance of the shaft system.

[0044] like Figure 1 , Figure 2 as well as Figure 3 As shown, the elastic foil type liquid metal bearing suitable for X-ray tubes is first specifically introduced:

[0045] The elastic foil type liquid metal bearing is arranged in a vacuum tube shell of an X-ray tube, and the elastic foil type liquid metal bearing comprises:

[0046] The central shaft 1 of the stator comprises a shaft body 11, and a thrust plate 12 is arranged on the outer peripheral wall of the shaft body 11;

[0047] The bearing sleeve 2 is used for coaxially connecting the rotating anode 6 of the X-ray tube. The bearing sleeve 2 has a sleeve cavity with a single-side opening. The bearing sleeve 2 is rotatably sleeved on the shaft body 11 and indirectly stops with one end surface of the thrust plate 12;

[0048] A cover 3 with a central through hole, the cover 3 is sleeved on the shaft body 11 and is sealed to the open end of the bearing sleeve 2, the cover 3 is indirectly stopped with the other end face of the thrust plate 12, the bearing sleeve 2 and the cover 3 jointly axially constrain the thrust plate 12, and a shaft seal gap is formed between the inner peripheral wall of the cover 3 and the outer peripheral wall of the shaft body 11;

[0049] The bearing system 4 includes a radial foil bearing 41, a first thrust foil bearing 42 and a second thrust foil bearing 43. The radial foil bearing 41 is arranged between the inner peripheral wall of the bearing sleeve 2 and the outer peripheral wall of the shaft body 11. The first thrust foil bearing 42 is arranged between the opening end of the bearing sleeve 2 and one end surface of the thrust plate 12. The second thrust foil bearing 43 is arranged between the other end surface of the thrust plate 12 and the cover 3.

[0050] There are liquid film gaps between the bearing sleeve 2 and the shaft body 11 and the thrust plate 12 respectively, and there is a liquid film gap between the cover 3 and the thrust plate 12. The liquid film gap is used to fill liquid metal.

[0051] In the elastic foil type liquid metal bearing of the utility model, a thrust plate 12 is provided on the outer peripheral wall of the shaft body 11, and the bearing sleeve 2 and the cover 3 jointly axially constrain the thrust plate 12. With such a configuration, the bearing sleeve 2 will not axially move relative to the central shaft 1, thereby facilitating the stable high-speed rotation of the rotating anode 6. More importantly, an elastic foil is used between the bearing sleeve 2 and the central shaft 1 and between the cover 3 and the central shaft 1 to provide additional Coulomb friction damping to improve the stability and anti-seismic performance of the elastic foil type liquid metal bearing, and liquid metal is filled between the bearing sleeve 2 and the central shaft 1 and between the cover 3 and the central shaft 1 as a lubricating medium to further improve the rotation speed of the rotating anode 6 and the bearing capacity of the elastic foil type liquid metal bearing. Specifically, the radial foil bearing 41, the first thrust foil bearing 42 and the second thrust foil bearing 43 provide additional Coulomb friction damping for the elastic foil type liquid metal bearing: the radial foil bearing 41 is used to carry the static and dynamic loads in the radial direction of the shaft system; the first thrust foil bearing 42 and the second thrust foil bearing 43 are used to carry the static and dynamic loads in the axial direction of the shaft system.

[0052] Therefore, the elastic foil type liquid metal bearing of the utility model can improve the high-speed rotation stability and vibration resistance of the rotating anode assembly, and can ensure the stable operation of the CT tube at higher rotation and revolution speeds, thereby improving the imaging performance and service life of the CT machine.

[0053] Furthermore, in order to drive the cover 3 and the bearing sleeve 2 to rotate synchronously, thereby driving the rotating anode 6 to rotate relative to the central axis 1, the elastic foil type liquid metal bearing suitable for the X-ray tube also includes a cylindrical rotor 5, which is coaxially fixed to the cover 3.

[0054] Furthermore, in order to facilitate assembly and adjust the liquid film gaps on both sides of the thrust plate 12 in the axial direction, the elastic foil type liquid metal bearing suitable for the X-ray tube further includes a sealing ring 7, which is sealed and connected to the bearing sleeve 2 and the cover 3 respectively, and the sealing ring 7 is gap-jacketed on the thrust plate 12, and a liquid film gap exists between the sealing ring 7 and the thrust plate 12. The sealing ring 7 has a variety of thicknesses, which can be selected according to preset requirements.

[0055] Furthermore, in order to facilitate the detachable connection of the cover 3 to the open end of the bearing sleeve 2, the cover 3 includes a sealing flange portion 31 and a shaft sealing sleeve portion 32 integrally formed with the sealing flange portion 31, and the second thrust foil bearing 43 is provided between the sealing flange portion 31 and the thrust plate 12.

[0056] Furthermore, in order to reduce the risk of liquid metal leakage, an anti-overflow groove 33 is provided on the inner peripheral wall of the shaft sealing sleeve 32 .

[0057] Furthermore, the bearing sleeve 2 is in a cap shape, and includes a cap body 21 and a brim 22 integrally formed with the cap body 21, and the first thrust foil bearing 42 is arranged between the brim 22 and the thrust plate 12. Specifically, the brim 22 has a plurality of connection holes, and the outer edge of the brim 22 is indirectly sealed and connected to the outer edge of the sealing flange 31 through a sealing ring 7.

[0058] Furthermore, if Figure 4 As shown, the radial foil bearing 41 includes a flat foil ring 411 outermostly on the shaft body 11 and a corrugated foil ring 412 outermostly on the flat foil ring 411 .

[0059] Furthermore, if Figure 5 As shown, the first thrust foil bearing 42 includes a plurality of first flat foils 421 and a plurality of first wave foils 422, all the first flat foils 421 correspond to all the first wave foils 422, and the first wave foils 422 are located on the side of the first flat foil 421 facing away from the thrust plate 12. Specifically, all the first flat foils 421 are in a circular array, and all the first wave foils 422 are also in a circular array.

[0060] Furthermore, if Figure 6 As shown, the first thrust foil bearing 42 and the second thrust foil bearing 43 have the same structure.

[0061] In summary, the utility model is applicable to the elastic foil type liquid metal bearing of the X-ray tube and the CT tube, and can improve the high-speed rotation stability and vibration resistance of the rotating anode assembly. Therefore, the utility model effectively overcomes various shortcomings of the prior art and has high industrial utilization value.

[0062] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed in the present invention shall still be covered by the claims of the present invention.

Claims

1. An elastic foil type liquid metal bearing suitable for an X-ray tube, wherein the elastic foil type liquid metal bearing is arranged in a vacuum tube shell of the X-ray tube, characterized in that: The elastic foil type liquid metal bearing comprises: A central axis (1) constituting the stator, the central axis (1) comprising a shaft body (11), and a thrust plate (12) is provided on the outer peripheral wall of the shaft body (11); A bearing sleeve (2), the bearing sleeve (2) is used for coaxially connecting to a rotating anode (6) of an X-ray tube, the bearing sleeve (2) having a sleeve cavity with a single-side opening, the bearing sleeve (2) being rotatably sleeved on the shaft body (11) and indirectly stopping with an end surface of a thrust plate (12); A cover (3) having a central through hole, the cover (3) being sleeved on the shaft body (11) in a clearance and being sealed to the open end of the bearing sleeve (2), the cover (3) being indirectly stoppered with the other end face of the thrust plate (12), the bearing sleeve (2) and the cover (3) jointly axially constraining the thrust plate (12), and a shaft seal gap being formed between the inner peripheral wall of the cover (3) and the outer peripheral wall of the shaft body (11); A bearing system (4), the bearing system (4) comprising a radial foil bearing (41), a first thrust foil bearing (42) and a second thrust foil bearing (43), the radial foil bearing (41) being arranged between the inner peripheral wall of the bearing sleeve (2) and the outer peripheral wall of the shaft body (11), the first thrust foil bearing (42) being arranged between the opening end of the bearing sleeve (2) and one end face of the thrust plate (12), and the second thrust foil bearing (43) being arranged between the other end face of the thrust plate (12) and the cover (3); There are liquid film gaps between the bearing sleeve (2) and the shaft body (11) and the thrust plate (12), respectively, and there is a liquid film gap between the cover (3) and the thrust plate (12), and the liquid film gap is used to fill liquid metal.

2. The elastic foil type liquid metal bearing suitable for an X-ray tube according to claim 1, characterized in that: The elastic foil type liquid metal bearing suitable for an X-ray tube further comprises a cylindrical rotor (5), and the rotor (5) is coaxially fixedly arranged on the cover (3).

3. The elastic foil type liquid metal bearing suitable for an X-ray tube according to claim 1, characterized in that: The elastic foil type liquid metal bearing suitable for an X-ray tube further comprises a sealing ring (7), the sealing ring (7) being respectively sealedly connected to the bearing sleeve (2) and the sealing cover (3), the sealing ring (7) being gap-coated on the thrust plate (12), and a liquid film gap being present between the sealing ring (7) and the thrust plate (12).

4. The elastic foil type liquid metal bearing suitable for an X-ray tube according to claim 1, characterized in that: The sealing cover (3) comprises a sealing flange portion (31) and a shaft sealing sleeve portion (32) integrally formed with the sealing flange portion (31), and the second thrust foil bearing (43) is provided between the sealing flange portion (31) and the thrust plate (12).

5. The elastic foil type liquid metal bearing suitable for an X-ray tube according to claim 4, characterized in that: An anti-overflow groove (33) is provided on the inner peripheral wall of the shaft sealing sleeve (32).

6. The elastic foil type liquid metal bearing suitable for an X-ray tube according to claim 1, characterized in that: The bearing sleeve (2) is in the shape of a cap, comprising a cap body (21) and a cap brim (22) integrally formed with the cap body (21), and the first thrust foil bearing (42) is provided between the cap brim (22) and the thrust plate (12).

7. The elastic foil type liquid metal bearing suitable for an X-ray tube according to claim 1, characterized in that: The radial foil bearing (41) comprises a flat foil ring (411) outermostly mounted on the shaft body (11) and a corrugated foil ring (412) outermostly mounted on the flat foil ring (411).

8. The elastic foil type liquid metal bearing suitable for an X-ray tube according to claim 1, characterized in that: The first thrust foil bearing (42) comprises a plurality of first flat foils (421) and a plurality of first wave foils (422), all the first flat foils (421) and all the first wave foils (422) correspond one to one, and the first wave foils (422) are located on a side of the first flat foil (421) facing away from the thrust plate (12).

9. The elastic foil type liquid metal bearing suitable for an X-ray tube according to claim 1, characterized in that: The first thrust foil bearing (42) and the second thrust foil bearing (43) have the same structure.

10. A CT tube, characterized in that: include: A vacuum tube shell, wherein a tube cavity of the vacuum tube shell forms a vacuum environment; A cathode insulating end sealing assembly, which is arranged at one end of the vacuum tube shell; A cathode assembly, which is disposed on the cathode insulating end sealing assembly and is located in the tube cavity; An anode insulating end sealing assembly, the anode insulating end sealing assembly is arranged at the other end of the vacuum tube shell; A rotating anode assembly, the rotating anode assembly comprising a rotating anode (6) and an elastic foil type liquid metal bearing suitable for an X-ray tube as claimed in any one of claims 1 to 9, wherein the rotating anode (6) is detachably connected to a bearing sleeve (2) of the elastic foil type liquid metal bearing.

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