Method for sealing liquid metal bearing by using spiral labyrinth

Abstract

The invention belongs to the technical field of bearings, and particularly relates to a method for sealing a liquid metal bearing through a spiral labyrinth. A CT bulb tube needs to work with high precision and stable operation, a traditional ball bearing has many defects when used in the CT bulb tube, and although a liquid metal bearing has advantages, a traditional sealing structure is difficult to meet the sealing and liquid metal flow guiding requirements of the CT bulb tube. In order to solve the problems, the bearing is mainly composed of a core shaft, a shaft sleeve, a labyrinth sealing structure and liquid metal, the core is the spiral labyrinth sealing structure, sealing teeth of the spiral labyrinth sealing structure are spiral and form a roundabout channel, and a tiny sealing gap is formed between the sealing teeth and the core shaft. In the working process, leakage is reduced by means of the throttling effect and liquid metal surface tension, and liquid metal is guided to flow reversely. Liquid metal leakage can be effectively reduced, stable rotation of the bulb tube is guaranteed, the imaging quality is improved, the equipment maintenance cost and the failure rate are reduced, powerful technical support is provided for improvement of the performance of the CT bulb tube, and the application prospect is good.

Description

Technical Field

[0001] The invention relates to the technical field of bearings, and in particular to a method for sealing a liquid metal bearing by using a spiral labyrinth. Background Art

[0002] In CT equipment, the tube is one of the key components. It rotates at high speed and requires high-precision and stable operation to ensure imaging quality. Bearings, as key components that support the rotating parts of the tube, have a crucial impact on its performance. When traditional ball bearings are used in CT tubes, they often have problems such as severe wear, insufficient lubrication, and poor heat dissipation, which affect the service life of the tube and the stability and accuracy of imaging. Liquid metal bearings are gradually being used in the field of CT tubes due to their advantages such as good self-lubrication, low friction coefficient, and excellent heat dissipation performance.

[0003] In practical applications, compared with traditional ball bearings, liquid metal bearings can provide higher heat capacity and stability, as well as stable output at faster speeds, thereby improving the stability and accuracy of CT imaging, and increasing work efficiency and service life. Therefore, when using liquid metal bearings, CT tubes can well solve the performance deficiencies of ball bearings.

[0004] At the same time, the traditional sealing structure is insufficient in meeting the sealing requirements of liquid metal bearings and guiding the flow of internal liquid metal. Although conventional labyrinth seals can prevent leakage to a certain extent, they have limited ability to regulate the complex flow of liquid metal under high-speed rotation conditions, making it difficult to achieve more efficient sealing and more reasonable medium flow guidance to further improve the performance of bearings and CT tubes. Summary of the invention

[0005] The purpose of the present invention is to provide a method for sealing a liquid metal bearing using a spiral labyrinth, which is applied to a CT tube. Through the unique spiral labyrinth sealing structure, on the one hand, the leakage of liquid metal is effectively reduced, and on the other hand, the spiral structure characteristics are utilized to generate a reverse flow of liquid metal medium when the bearing is working, thereby optimizing the distribution and circulation of liquid metal inside the bearing, improving the performance of the bearing and the working stability and imaging quality of the CT tube.

[0006] The liquid metal bearing with a spiral labyrinth seal structure for a CT tube proposed by the present invention is mainly composed of a core shaft, a sleeve, a labyrinth seal structure and liquid metal filled therein;

[0007] The main structure of the spiral labyrinth seal is composed of spiral sealing teeth;

[0008] Furthermore, the spiral sealing teeth are arranged on the inner ring of the labyrinth sealing structure and extend spirally along the axial direction. The radial cross-sectional shape thereof can be a suitable shape such as a rectangle or a trapezoid. Selecting different shapes is conducive to better guiding the flow of liquid metal and enhancing the sealing effect;

[0009] Furthermore, the spiral sealing teeth form a tortuous spiral sealing channel, and the spiral parameters are designed according to factors such as the specific dimensions of the bearing, the operating speed, and the physical properties of the liquid metal. Through reasonable setting of the spiral parameters, it is ensured that good sealing effects can be achieved under different working conditions, and at the same time, the liquid metal can be effectively guided to generate the desired reverse flow;

[0010] Furthermore, a tiny sealing gap is provided between the spiral sealing teeth and the mandrel, and the size of this gap is optimized according to the viscosity, surface tension of the liquid metal, and the rotational speed of the bearing, etc.;

[0011] Furthermore, this tiny gap can not only adapt to the dimensional changes of the bearing caused by factors such as thermal expansion and contraction during high-speed rotation, but also prevent the leakage of liquid metal by means of the throttling effect and the characteristics of the liquid metal itself, and cooperate with the spiral structure to guide the flow of liquid metal.

[0012] Furthermore, the working principle of this invention is as follows: When the CT tube starts and the rotor of the liquid metal bearing begins to rotate, in addition to playing the conventional roles of lubrication and heat dissipation inside the bearing, due to the existence of the spiral labyrinth sealing structure, a unique flow phenomenon occurs. The spiral sealing structure is filled with fluid. When the shaft rotates at a high speed, the spiral groove will generate a force opposite to the axial direction of the fluid medium flow. Under this acting force, the fluid medium flows in the reverse direction, preventing the leakage of the fluid medium, thereby establishing a dynamic seal;

[0013] Furthermore, under the action of centrifugal force and the driving of the rotor rotation, the liquid metal originally has a tendency to leak to the outside of the bearing. However, during the process of attempting to leak out through the spiral labyrinth sealing structure, the liquid metal needs to flow along the tortuous spiral sealing channel composed of the spiral sealing teeth. During this process, a throttling effect is generated in the sealing channel. Each time the liquid metal passes through the gap between the sealing teeth and the sealing groove, the state of the gas pressure, flow rate, etc. changes, forming an obstacle to the flow of the liquid metal; at the same time, the surface tension of the liquid metal itself also makes it difficult to easily break through these tiny gaps, thereby effectively preventing the liquid metal from leaking to the outside of the bearing.

[0014] In summary, the beneficial effects of the present invention are as follows:

[0015] 1. Excellent sealing performance: The spiral labyrinth seal structure, through its unique spiral detour sealing channel, combines the throttling effect and the surface tension of liquid metal, can significantly reduce the leakage of liquid metal, ensure sufficient liquid metal inside the bearing, maintain good lubrication and heat dissipation conditions, and extend the service life of the bearing and the CT tube.

[0016] 2. Improve the overall performance of the CT tube: Effectively solve the problem of liquid metal leakage and optimize the flow characteristics of the internal liquid metal, ensure the stable rotation of the CT tube during operation, contribute to improving the imaging accuracy and quality of the CT tube, and reduce the maintenance cost and failure rate of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings, where:

[0018] Figure 1 is the overall structure sectional view of the liquid metal bearing with the spiral labyrinth seal structure of the present invention;

[0019] Figure 2 is the structure diagram of the spiral labyrinth seal; DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0021] Please refer to Figure 1 and Figure 2 As shown, the embodiment of the present invention provides a liquid metal bearing with a spiral labyrinth seal structure, including a bushing 1, a mandrel 2, a spiral labyrinth seal structure 3, a bearing clearance 4, a mandrel thrust disk 21, and a spiral seal tooth 31. The relative position relationship between the mandrel, the bushing, and the spiral labyrinth seal structure is shown, clearly presenting the layout structure of the entire bearing.

[0022] Refer specifically to Figure 1As shown, the bushing 1 and the mandrel 2 are respectively made of suitable high-strength, high-hardness metal materials with good thermal stability and corrosion resistance according to the design requirements. Through precise machining processes, the dimensional accuracy of their inner and outer diameters, thickness, etc. and the surface finish are ensured to meet the installation and use requirements for high-speed rotation in the CT tube.

[0023] Furthermore, refer to Figure 2 As shown, machining operations such as milling and drilling are performed on the spiral labyrinth seal structure 3 according to the spiral parameters of the preset spiral seal teeth 31. The accuracy of each machining dimension is strictly controlled to ensure the accuracy of the shape, size, and spiral direction of the spiral seal teeth.

[0024] Furthermore, after machining, surface treatments such as polishing and cleaning are performed on the components to remove impurities such as burrs and oil stains generated during the machining process, ensuring the flatness and surface finish of the spiral labyrinth seal structure surface, laying a foundation for achieving good sealing and guiding the flow of liquid metal.

[0025] Furthermore, the bushing 1 and the mandrel 2 are assembled, and the coaxiality requirement should be maintained during the installation process of the bushing 1 and the mandrel 2.

[0026] Furthermore, the liquid metal is injected into the bearing clearance 4 between the bushing 1 and the mandrel 2, so that the liquid metal is evenly distributed inside the bearing, preparing for subsequent lubrication and heat dissipation.

[0027] Furthermore, the end face of the thrust disk 21 is overlapped and fitted with the end face of the opening direction of the bushing 1 to complete the assembly of the bushing 1 and the mandrel.

[0028] Furthermore, the spiral labyrinth seal structure 3 is installed, which is coaxial with the mandrel 2 and the bushing 1 and is fitted with the end face of the mandrel thrust disk 21.

[0029] Furthermore, during the assembly process, it is necessary to ensure that each spiral seal tooth 31 can strictly guarantee the sealing gap and meet the design requirements.

[0030] Furthermore, the assembled liquid metal bearing is debugged. During the initial operation stage, the working state of the bearing is monitored through various monitoring devices, focusing on the temperature change of the liquid metal, whether there are leakage signs, the flow condition of the liquid metal, and the vibration condition of the bearing, etc.

[0031] Furthermore, according to the monitoring data, necessary fine-tuning and optimization are performed on the relevant parameters of the bearing to ensure that the spiral labyrinth seal structure can continuously and efficiently play the roles of sealing and regulating the flow of liquid metal, enabling the liquid metal bearing to operate stably in the CT tube and ensuring the normal operation and imaging quality of the CT tube.

[0032] The liquid metal bearing with a spiral labyrinth seal structure of the present invention effectively solves the problems of liquid metal leakage in the liquid metal bearing of a CT tube and optimization of the internal liquid metal flow through innovative structural design, provides strong technical support for improving the performance and reliability of the CT tube, and has good application prospects and important practical significance.

Claims

1. A method for sealing a liquid metal bearing using a spiral labyrinth, applied to a CT tube, characterized in that: It includes a core shaft, a sleeve, a labyrinth sealing structure and liquid metal filled between the core shaft and the sleeve; the inner ring of the labyrinth sealing structure is provided with spiral sealing teeth, and the spiral sealing teeth extend spirally along the axial direction to form a tortuous spiral sealing channel; a tiny sealing gap is provided between the spiral sealing teeth and the core shaft.

2. The liquid metal bearing with a spiral labyrinth seal structure according to claim 1, characterized in that: The radial cross-section of the spiral sealing teeth is rectangular or trapezoidal.

3. The liquid metal bearing with a spiral labyrinth seal structure according to claim 1, characterized in that: The spiral parameters of the spiral sealing teeth are designed according to the specific size of the bearing, the operating speed and the physical properties of the liquid metal.

4. The liquid metal bearing with a spiral labyrinth seal structure according to claim 1, characterized in that: The size of the sealing gap is optimized based on the viscosity and surface tension of the liquid metal and the rotational speed of the bearing.

5. The liquid metal bearing with a spiral labyrinth seal structure according to claim 1, wherein the manufacturing method thereof comprises the following steps: The core shaft and sleeve are made of metal materials with high strength, good thermal stability and corrosion resistance. The core shaft and sleeve are precisely dimensioned through precision machining technology to ensure dimensional accuracy and surface finish. High-precision CNC machining equipment is used to mill and drill the inner surface of the sealing ring of the labyrinth seal structure according to the preset spiral parameters to form spiral sealing teeth. After machining, the components are surface treated. Suitable liquid metal is selected and injected into the gap between the sleeve and the core shaft to ensure that the liquid metal is evenly distributed. The spiral labyrinth seal structure is assembled with the core shaft and sleeve to ensure coaxiality and ensure that the sealing gap of the spiral sealing teeth meets the design requirements. The assembled liquid metal bearing is debugged, the bearing working status is monitored, and the bearing-related parameters are fine-tuned and optimized according to the monitoring data.

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