Method for sealing liquid metal bearing through 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 labyrinth. A CT bulb tube is high in imaging quality requirement and needs to stably rotate at a high speed, various defects exist when a traditional ball bearing is used for the CT bulb tube, and although a liquid metal bearing has advantages, liquid metal is prone to leakage. In order to solve the problem, the bearing is mainly composed of a core shaft, a shaft sleeve, gallium-based liquid metal and a labyrinth seal structure. The labyrinth sealing structure is composed of a plurality of alternately arranged annular sealing teeth and annular sealing grooves and is matched with a corresponding structure of the mandrel to form a circuitous channel, and a sealing gap of the labyrinth sealing structure is optimally designed. During working, leakage is reduced through the throttling effect and liquid metal surface tension. The sealing performance is excellent, the reliability and the service life of the bearing can be improved, the working stability and the imaging quality of the CT bulb tube are guaranteed, an effective scheme is provided for solving the problem of liquid metal leakage, and the application prospect is wide.

Description

Technical Field

[0001] The present invention relates to the technical field of bearings, and particularly to a method for using a labyrinth seal for a liquid metal bearing. Background Art

[0002] In a CT device, the X-ray tube is one of the key components, which rotates at a high speed and requires a high-precision and stable operating state to ensure the imaging quality. As a key component for supporting the rotating parts of the X-ray tube, the bearing has a crucial impact on its performance. When traditional ball bearings are applied to a CT X-ray tube, problems such as severe wear, insufficient lubrication, and poor heat dissipation often occur, affecting the service life of the X-ray tube and the stability and accuracy of imaging. Liquid metal bearings, with their advantages such as good self-lubrication, low friction coefficient, and excellent heat dissipation performance, have gradually been applied in the field of CT X-ray tubes.

[0003] In terms of practical applications, compared with traditional ball bearings, liquid metal bearings can provide higher heat capacity and stability, as well as stable output at higher rotational speeds, thereby improving the stability and accuracy of CT imaging, as well as the working efficiency and service life. Therefore, when a CT X-ray tube uses a liquid metal bearing, it can well solve the deficiencies shown by ball bearings in terms of performance.

[0004] However, during actual use, liquid metal is likely to leak out from parts such as the gaps of the bearing. This not only causes insufficient liquid metal inside the bearing, affecting the lubrication and heat dissipation effects, and then reducing the performance and service life of the bearing, but may also have an adverse impact on other components inside the CT X-ray tube, such as problems like contamination and short circuits, seriously affecting the normal operation of the CT X-ray tube and the imaging quality. Currently, for liquid metal bearings in an application scenario such as a CT X-ray tube with high precision, high rotational speed, and a complex working environment, conventional sealing methods often fail to meet the sealing requirements, having defects such as poor sealing effect and low reliability. Therefore, there is an urgent need for an efficient sealing structure specifically for liquid metal bearings and applicable to CT X-ray tubes to solve the problem of liquid metal leakage. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for using a labyrinth seal for a liquid metal bearing, which is applied to a CT X-ray tube. Through a cleverly designed labyrinth seal structure, the leakage of liquid metal is effectively reduced, ensuring a stable amount of liquid metal inside the bearing, and thus improving the overall performance, working stability, and service life of the bearing and the CT X-ray tube.

[0006] The liquid metal bearing with a labyrinth seal structure designed for a CT X-ray tube of the present invention mainly includes a mandrel, a bushing, a gallium-based liquid metal, and a seal structure for bearing sealing.

[0007] The key feature of the bearing sealing structure is the provision of a labyrinth sealing structure;

[0008] Furthermore, the labyrinth sealing structure is composed of multiple annular sealing teeth and annular sealing grooves arranged alternately in sequence. It is continuously distributed along the axial direction on the inner surface of the sealing ring, and its radial cross-sectional shape is trapezoidal;

[0009] Furthermore, corresponding annular sealing teeth and annular sealing grooves that cooperate with the sealing ring are also machined on the mandrel part. It is also continuously distributed along the circumferential direction, and its shape is adapted to the annular sealing teeth to form a tortuous sealing channel;

[0010] Furthermore, a tiny sealing gap is left between the annular sealing teeth and the annular sealing grooves, and the size of this gap is optimized according to the physical properties of the liquid metal (such as viscosity, surface tension, etc.) and the operating parameters of the bearing (such as rotational speed, temperature, etc.);

[0011] Furthermore, this tiny gap can not only allow the bearing to undergo a small amount of deformation due to factors such as thermal expansion and contraction during high-speed rotation without hindrance, but also rely on the throttling effect of the labyrinth sealing structure and the surface tension of the liquid metal itself, etc., to prevent the leakage of the liquid metal.

[0012] Furthermore, when the CT tube starts to work and the liquid metal bearing rotates accordingly, the liquid metal plays a lubricating and heat-dissipating role inside the bearing. Due to the high-speed rotation of the bearing, the liquid metal will be affected by various forces such as centrifugal force and has a tendency to leak to the outside of the bearing.

[0013] Furthermore, the labyrinth sealing structure begins to function. During the process of the liquid metal attempting to leak out through the labyrinth sealing structure, it needs to flow along the tortuous sealing channel composed of annular sealing teeth and annular sealing grooves. During this process, a throttling effect occurs in the sealing channel, that is, when the liquid metal passes through the gap between each sealing tooth and 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 and ensuring that the liquid metal can be stably retained inside the bearing to maintain a good lubricating and heat-dissipating state.

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

[0015] 1. Excellent sealing performance: Through the unique tortuous channel design of the labyrinth sealing structure and the synergistic effect of the throttling effect and the surface tension of the liquid metal, the leakage amount of the liquid metal from the bearing can be greatly reduced, ensuring that there is sufficient liquid metal inside the bearing and guaranteeing the continuity and stability of lubrication and heat dissipation.

[0016] 2. Improve the reliability and lifespan of the bearing: Effectively avoid problems such as the decline in bearing performance and increased wear caused by the leakage of liquid metal, extend the service life of the bearing, reduce the frequency of maintenance or replacement of the CT tube due to bearing failures, and lower the usage cost.

[0017] 3. Ensure the working stability and imaging quality of the CT tube: Prevent the adverse effects of liquid metal leakage on other components inside the CT tube, maintain the cleanliness inside the tube and the normal electrical and mechanical environment, help the tube maintain a stable rotating state during operation, and thereby improve the accuracy and quality of CT tube imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] 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:

[0019] Figure 1 is the overall structural sectional view of the liquid metal bearing with a labyrinth seal structure of the present invention;

[0020] Figure 2 is the structural diagram of the labyrinth seal ring of the liquid metal bearing;

[0021] Figure 3 is the structural diagram of the mandrel of the liquid metal bearing; DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with 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.

[0023] Please refer to Figures 1 to 3 As shown, the embodiment of the present invention provides a liquid metal bearing with a labyrinth seal structure, including a sleeve 1, a mandrel 2, a seal ring 3, and a bearing clearance 4. Clearly presents the relative position relationship and overall layout among the mandrel, the sleeve, and the labyrinth seal structure.

[0024] In particular, refer to Figure 2 As shown, the mandrel 2 is machined with a thrust disk 21 and a labyrinth seal groove 22;

[0025] Furthermore, select appropriate metal materials with high strength, high hardness, good thermal stability, and corrosion resistance to manufacture the mandrel and the sleeve;

[0026] Further, use a high-precision numerical control machining equipment to strictly machine the labyrinth seal groove 22 on the mandrel 2 according to the designed shape, size, and radial cross-sectional shape parameters.

[0027] When specifically participating Figure 3 As shown, the seal ring 3 is machined with an annular seal tooth 31 that mates with the mandrel labyrinth seal ring.

[0028] Further, use a high-precision numerical control machining equipment to strictly machine the annular seal tooth 31 on the seal ring 3 according to the designed shape, size, and radial cross-sectional shape parameters.

[0029] Further, after machining, perform treatments such as polishing and cleaning on the seal structure to remove impurities such as burrs and oil stains generated during the machining process, and ensure the flatness and smoothness of the surface of the labyrinth seal structure to better achieve the sealing function.

[0030] Further, initially assemble the seal ring 3 and the mandrel 2, and the seal ring and the mandrel 2 should be installed with coaxiality.

[0031] Further, closely fit the end face of the seal ring 3 with the end face of the mandrel 2.

[0032] Further, engage the annular seal tooth 31 of the seal ring 3 with the labyrinth seal groove 22 of the mandrel 2 to complete the assembly of the seal ring 3.

[0033] Further, assemble the sleeve 1 and the mandrel 2, and the sleeve 1 and the mandrel 2 should be installed with coaxiality.

[0034] Further, inject the liquid metal into the gap 4 between the sleeve 1 and the mandrel 2 to ensure that the liquid metal is evenly distributed inside the bearing, and make preparations for subsequent lubrication and heat dissipation.

[0035] Further, after filling the liquid metal, closely fit the end face of the thrust disk 21 with the end face of the sleeve 1.

[0036] Further, further complete the overlapping fit of the stepped end faces of the seal ring 3 and the sleeve 1 to complete the final seal of the liquid metal bearing.

[0037] Further, conduct a trial run and leakage measurement after installation. In the initial operation stage, closely monitor the working state of the bearing through various monitoring devices (such as temperature sensors, leakage detection devices, etc.), and focus on the temperature change of the liquid metal, whether there are leakage signs, and the vibration condition of the bearing, etc.

[0038] Furthermore, based on the monitoring data, necessary fine-tuning and optimization are carried out on the relevant parameters of the bearing (such as the sealing gap of the labyrinth seal structure, etc.) to ensure that the labyrinth seal structure can continuously and efficiently play the sealing role, enabling the liquid metal bearing to operate stably in the CT tube and guaranteeing the normal operation and imaging quality of the CT tube.

[0039] The liquid metal bearing with a labyrinth seal structure of the present invention provides an effective solution to the problem of liquid metal leakage of the liquid metal bearing in the CT tube through the innovative design of the labyrinth seal structure, has significant technical advantages and broad application prospects, and is of great significance for improving the performance and reliability of the CT tube.

Claims

1. A method of using a labyrinth-sealed liquid metal bearing, applied to a CT tube, characterized in that: It comprises a core shaft, a sleeve, a gallium-based liquid metal filled between the core shaft and the sleeve, and a labyrinth seal structure for bearing sealing; the labyrinth seal structure is arranged on the inner surface of a sealing ring, and is composed of a plurality of annular sealing teeth and annular sealing grooves which are alternately arranged in sequence, are continuously distributed axially along the inner surface of the sealing ring, and have a trapezoidal radial cross-section shape; the core shaft is processed with corresponding annular sealing teeth and annular sealing grooves which cooperate with the sealing ring, are continuously distributed along the circumferential direction, and have a shape which matches the annular sealing teeth of the sealing ring, so as to form a tortuous sealing channel; a small sealing gap is provided between the annular sealing teeth and the annular sealing grooves.

2. The liquid metal bearing with a labyrinth seal structure according to claim 1, characterized in that: The size of the sealing gap is optimized and designed according to the physical properties of the liquid metal and the working parameters of the bearing.

3. The liquid metal bearing with a labyrinth seal structure according to claim 1, characterized in that: The core shaft and the sleeve are made of metal materials with high strength, high hardness, good thermal stability and corrosion resistance.

4. The liquid metal bearing with a labyrinth seal structure according to claim 1, characterized in that: During installation, keep the labyrinth seal structure coaxial with the core shaft, install it in line with the end face of the core shaft thrust plate, and ensure that the annular seal teeth are accurately aligned with the corresponding annular seal grooves, and the sealing gap meets the design requirements.

5. The liquid metal bearing with a labyrinth seal structure according to claim 1, wherein the manufacturing method thereof comprises the following steps: Select suitable high-strength, high-hardness metal materials with good thermal stability and corrosion resistance to manufacture the core shaft and sleeve, use precision machining technology to accurately process the core shaft and sleeve to ensure dimensional accuracy and surface finish, and perform fine processing on the labyrinth seal structure; select liquid metal suitable for the working environment of the CT tube, and inject a predetermined amount into the gap between the sleeve and the core shaft through a special liquid injection device to ensure that the liquid metal is evenly distributed; install the labyrinth seal structure on the core shaft to ensure that the coaxiality, alignment of the sealing teeth and the sealing groove, and the sealing gap meet the requirements; conduct trial operation and leakage test on the installed bearings, monitor the working status through monitoring equipment, and fine-tune and optimize the bearing-related parameters based on the monitoring data.

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