Bearing assembly for X-ray bulb tube
By adopting all-ceramic bearings and conductive ring assemblies, the problems of difficult processing and high cost of X-ray tube rotating anode bearings have been solved, achieving stable operation at high temperatures and improved high-speed performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- LUOYANG YUNXIU DIGITAL TECHNOLOGY CO LTD
- Filing Date
- 2025-07-02
- Publication Date
- 2026-05-22
AI Technical Summary
In the existing technology, the rotating anode bearing of X-ray tubes has a larger clearance due to the difference in thermal expansion coefficients between ceramic bearings and metal bearings, which causes the rolling elements to slip, reducing high-speed performance. At the same time, it is difficult to process and manufacture and has high cost.
It adopts all-ceramic bearings and conductive ring assemblies, taking advantage of the high temperature resistance and low thermal expansion characteristics of ceramic bearings, and realizes current conduction between rotor shaft and bearing housing through conductive rings, and is mass-produced using existing manufacturing processes.
Stable operation of ceramic bearings at high temperatures has been achieved, avoiding rotor idling and jamming, and reducing manufacturing difficulty and cost.
Smart Images
Figure CN224266531U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of rotating anode bearing assemblies, specifically a bearing assembly for X-ray tubes. Background Technology
[0002] With the continuous development of medical technology, X-ray tubes (computed tomography scanners) have been increasingly widely used in medical, industrial, security inspection, and scientific research and education fields. When an X-ray tube is working, a thermionic cloud is generated around the cathode filament. Under the action of high voltage at the anode and cathode, high-speed electrons in the thermionic cloud fly towards the high-speed rotating anode and strike the anode target disk. The high-speed electrons interact with the atoms of the target disk material to produce X-rays. Only a small portion of the energy is converted into X-rays, while most of the energy is converted into heat and deposited on the anode target disk. The anode target disk dissipates the heat to the outside of the X-ray tube through heat conduction via the rotor and bearings.
[0003] In the aforementioned rotating anode bearings, the first rolling bearing, located closer to the anode target, operates at a temperature between 500°C and 580°C, while the second rolling bearing, located further away from the anode target, operates at a maximum temperature of only about 400°C. In existing technology, such as the utility model patent application with publication number CN217177191U, to address the problem of short bearing life caused by excessively high temperatures on the side closer to the target plate, a ceramic bearing is used on the side closer to the target plate. This leverages the high-temperature resistance of ceramics to mitigate the effects of high temperatures.
[0004] However, due to the need for electrical conductivity between the rotor shaft and the bearing housing, the utility model patent application with publication number CN217177191U uses a ceramic bearing for the bearing closer to the target plate, while the bearing farther from the target plate is still made of metal to meet the conductivity requirements. Since the coefficient of thermal expansion of ceramic materials is much smaller than that of metal materials, this arrangement easily leads to increased clearance in the ceramic bearing and slippage of the rolling elements, thereby reducing the high-speed performance of the rotating anode bearing.
[0005] To address the aforementioned issues, utility model patent CN217177191U specifically defines parameters such as radial clearance, raceway radius of curvature, and contact angle for ceramic and metal bearings. Ceramic and metal bearings meeting these parameters can only be manufactured as custom-made parts for the bearing assembly. This not only presents manufacturing difficulties but also results in high overall costs. Utility Model Content
[0006] The purpose of this invention is to provide a bearing assembly for X-ray tubes that can solve the technical problems of difficult processing and high cost in the existing technology.
[0007] To achieve the above objectives, the present invention adopts the following technical solution.
[0008] An X-ray tube bearing assembly includes a bearing housing and a rotor shaft. The bearing housing is a barrel-shaped structure with one end open. One end of the rotor shaft is provided with an anode target disk, and the other end extends into the bearing housing and is rotatably connected to the bearing housing coaxially. The rotor shaft is rotatably connected to the bearing housing through two ceramic bearings. A conductive ring assembly for conducting electricity is also provided between the rotor shaft and the bearing housing. The conductive ring assembly includes a brush and a conductive ring, which are respectively disposed on the bearing housing and the rotor shaft. Current can be conducted between the rotor shaft and the bearing housing through the cooperation of the brush and the conductive ring.
[0009] Furthermore, the ceramic bearing is either an all-ceramic bearing or a ceramic ball bearing.
[0010] Furthermore, the ceramic bearing is an angular contact ball bearing.
[0011] Furthermore, the two angular contact ball bearings are installed back-to-back or face-to-face.
[0012] Furthermore, the conductive ring assembly is positioned between the two ceramic bearings.
[0013] Furthermore, the conductive ring of the conductive ring assembly is located between the inner rings of the two ceramic bearings.
[0014] Furthermore, a retaining ring is provided on the inner wall of the bearing housing near the opening, and an elastic structure is provided between the closed end of the bearing housing and the outer ring of the closed end bearing, which is used to push the outer ring of the closed end bearing through the spacer to press the outer ring of the open end bearing onto the retaining ring.
[0015] Furthermore, the brushes of the conductive ring assembly are mounted on the bearing housing via spacers.
[0016] Furthermore, the elastic structure is a helical spring, with multiple springs evenly arranged circumferentially along the outer ring of the closed-end shaft bearing. One end of the spring contacts the end face of the outer ring of the closed-end shaft bearing, and the other end contacts the closed end face of the bearing housing.
[0017] Furthermore, the elastic structure is a disc spring, with one end of the disc spring contacting the end face of the outer ring of the closed-end shaft bearing, and the other end contacting the closed end face of the bearing housing.
[0018] By adopting the above technical solution, this utility model has the following beneficial effects:
[0019] 1. This utility model uses two ceramic bearings, taking advantage of the small coefficient of thermal expansion and high temperature resistance of ceramic bearings to solve the problems of roller slippage and reduced high-speed performance. In addition, a high-speed conductive ring assembly is used to solve the conductivity requirements between the rotor shaft and the bearing housing.
[0020] 2. The ceramic bearing and high-speed conductive ring assembly in this utility model can both utilize existing product structures and manufacturing processes, enabling mass production, shortening the manufacturing cycle, and reducing manufacturing costs. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the overall structure in Embodiment 1 of this utility model.
[0022] Figure 2 This is a schematic diagram of the overall structure in Embodiment 2 of this utility model.
[0023] Figure descriptions: 1. Bearing housing, 11. Snap ring, 2. Rotor shaft, 21. Anode target disk, 3. Ceramic bearing, 4. Slip ring, 41. Conductive ring, 5. Elastic structure, 6. Spacer. Detailed Implementation
[0024] To make the objectives, technical solutions, and advantages of this utility model clearer, the features and performance of a bearing assembly for an X-ray tube according to this utility model will be further described in detail below with reference to the accompanying drawings and embodiments.
[0025] Example 1
[0026] Please see the appendix Figure 1 A bearing assembly for an X-ray tube includes a bearing housing 1 and a rotor shaft 2.
[0027] The bearing housing 1 is a barrel-shaped structure with one end open. The rotor shaft 2 has an anode target disk 21 at one end and the other end extends into the bearing housing 1 and is coaxially rotatably connected to the bearing housing 1. The rotor shaft 2 is rotatably connected to the bearing housing 1 through two ceramic bearings 3.
[0028] The ceramic bearing 3 is either an all-ceramic bearing or a ceramic ball bearing, and is an angular contact ball bearing. The two angular contact ball bearings are installed back-to-back or face-to-face. Preferably, this invention uses all-ceramic bearings, and the installation method is back-to-back.
[0029] A conductive ring assembly 4 for conducting electricity is also provided between the rotor shaft 2 and the bearing housing 1. The conductive ring assembly 4 is located between the two ceramic bearings 3.
[0030] The conductive ring assembly 4 includes a brush and a conductive ring 41. The brush and the conductive ring 41 are respectively disposed on the bearing housing 1 and the rotor shaft 2. Current can be conducted between the rotor shaft 2 and the bearing housing 1 through the cooperation of the brush and the conductive ring 41.
[0031] The inner wall of the bearing housing 1 is provided with a retaining ring 11 near the opening. An elastic structure 5 is provided between the closed end of the bearing housing 1 and the outer ring of the closed end bearing, which is used to push the outer ring of the closed end bearing through the spacer 6 to press the outer ring of the open end bearing onto the retaining ring 11.
[0032] The conductive ring 41 in the conductive ring assembly 4 is located between the inner rings of the two ceramic bearings 3. The brush is located on the bearing seat through the spacer 6, and there are multiple brushes, which are respectively matched with the annular grooves on the conductive ring 41.
[0033] The elastic structure 5 is a helical spring. Multiple springs are evenly arranged along the circumference of the outer ring of the closed-end shaft bearing. One end of the spring contacts the end face of the outer ring of the closed-end shaft bearing, and the other end contacts the closed end face of the bearing seat 1.
[0034] In practice, the ceramic bearing 3 and the conductive ring 41 are sequentially installed on the rotor shaft 2, and the ceramic bearing 3, the conductive ring 41 and the rotor shaft 2 are all interference fits.
[0035] The rotor shaft 2, together with the ceramic bearing 3, conductive ring 41 and spacer 6 mounted on the rotor shaft 2, is installed into the inner cavity of the bearing housing 1. The ceramic bearing 3 and spacer 6 are clearance fit with the inner wall of the bearing housing 1 and can slide along the axis of the bearing housing 1.
[0036] The elastic structure 5 is a spring. Multiple springs are located inside the bearing housing 1 near the closed end, and are evenly distributed along the circumference of the outer ring of the closed-end bearing. One end of the spring contacts the end face of the closed end of the bearing housing 1, and the other end contacts the end face of the outer ring of the closed-end bearing. The compressed spring pushes the outer ring of the closed-end bearing away from the end face of the closed end of the bearing housing 1, and presses the outer ring of the closed-end bearing against the retaining ring 11 through the spacer ring 6.
[0037] The conductive ring assembly 4 includes a brush and a conductive ring 41. The axial length of the conductive ring 41 is less than the axial length of the spacer 6 to prevent the conductive ring 41 from contacting the inner ring of the ceramic bearing 3. The fit between the brush and the conductive ring 41 has an axial float to ensure that all axial forces from the rotor shaft 2 are borne by the ceramic bearing 3. The conductive ring assembly 4 is a common component, and its structure and principle will not be explained in detail.
[0038] When the bearing assembly is working, the rotor shaft 2, together with the anode target disk 21, rotates at high speed using the ceramic bearing 3. Due to the high temperature resistance and low coefficient of thermal expansion of ceramic materials, it can operate stably for a long time under high temperature conditions. Furthermore, since both bearings are ceramic bearings, the difference in their thermal expansion is negligible, thus avoiding malfunctions such as rotor idling and jamming.
[0039] Current is conducted between the bearing housing 1 and the rotor shaft 2 through the high-speed conductive ring assembly 4.
[0040] Example 2
[0041] like Figure 2As shown, unlike Embodiment 1, in Embodiment 2, the elastic structure 5 is a disc spring. One end of the disc spring contacts the end face of the outer ring of the closed-end bearing, and the other end contacts the closed end face of the bearing housing 1. The compressed disc spring pushes the outer ring of the closed-end bearing away from the closed end face of the bearing housing 1, and presses the outer ring of the open-end bearing onto the retaining ring 11 through the spacer 6.
[0042] It should be noted that the parts not described in detail in this solution are all prior art. The above embodiments are only used to illustrate the present utility model, but the present utility model is not limited to the above embodiments. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present utility model shall fall within the protection scope of the present utility model.
Claims
1. A bearing assembly for an X-ray tube, comprising a bearing housing (1) and a rotor shaft (2), wherein the bearing housing (1) is a barrel-shaped structure with one end open, and one end of the rotor shaft (2) is provided with an anode target disk (21), and the other end extends into the bearing housing (1) and is coaxially rotatably connected to the bearing housing (1), characterized in that: The rotor shaft (2) is rotatably connected to the bearing housing (1) through two ceramic bearings (3). A conductive ring assembly (4) for conducting electricity is also provided between the rotor shaft (2) and the bearing housing (1). The conductive ring assembly (4) includes a brush and a conductive ring (41). The brush and the conductive ring (41) are respectively set on the bearing housing (1) and the rotor shaft (2). The current can be conducted between the rotor shaft (2) and the bearing housing (1) through the cooperation of the brush and the conductive ring (41).
2. The bearing assembly for an X-ray tube as described in claim 1, characterized in that: The ceramic bearing (3) is an all-ceramic bearing or a ceramic ball bearing.
3. The bearing assembly for an X-ray tube as described in claim 1, characterized in that: The ceramic bearing (3) is an angular contact ball bearing.
4. The bearing assembly for an X-ray tube as described in claim 3, characterized in that: The two angular contact ball bearings are installed back-to-back or face-to-face.
5. A bearing assembly for an X-ray tube as described in claim 1, characterized in that: The conductive ring assembly (4) is located between the two ceramic bearings (3).
6. The bearing assembly for an X-ray tube as described in claim 5, characterized in that: The conductive ring (41) of the conductive ring assembly (4) is located between the inner rings of the two ceramic bearings (3).
7. A bearing assembly for an X-ray tube as described in claim 1, characterized in that: The inner wall of the bearing housing (1) is provided with a retaining ring (11) near the opening. An elastic structure (5) is provided between the closed end of the bearing housing (1) and the outer ring of the closed end bearing, which is used to push the outer ring of the closed end bearing through the spacer (6) to press the outer ring of the open end bearing onto the retaining ring (11).
8. A bearing assembly for an X-ray tube as described in claim 7, characterized in that: The brush of the conductive ring assembly (4) is mounted on the bearing housing (1) via a spacer (6).
9. A bearing assembly for an X-ray tube as described in claim 7, characterized in that: The elastic structure (5) is a helical spring. Multiple springs are evenly arranged along the circumference of the outer ring of the closed-end shaft bearing. One end of the spring contacts the end face of the outer ring of the closed-end shaft bearing, and the other end contacts the closed end face of the bearing seat (1).
10. A bearing assembly for an X-ray tube as described in claim 7, characterized in that: The elastic structure (5) is a disc spring. One end of the disc spring contacts the end face of the outer ring of the closed-end shaft bearing, and the other end contacts the closed end face of the bearing housing (1).