Device for determining the friction coefficient of rolling bearings in high-temperature environments

Abstract

The utility model discloses a device for measuring friction coefficient of rolling bearing under high temperature environment relates to nuclear engineering field, including platform, the top of platform is provided with magnetorheological brake, rotating electric machine, and one end of magnetorheological brake is provided with output shaft, one end of rotating electric machine is provided with input shaft, and the outer wall of input shaft is installed with angular displacement sensor, torque sensor, one end of output shaft, input shaft is provided with high temperature autoclave kettle body, and the top of high temperature autoclave kettle body is provided with water pump, cold water tank, one end of high temperature autoclave kettle body is provided with locking fixture. The utility model discloses through the setting of output shaft, input shaft, can measure the friction torque of rolling bearing and friction coefficient simultaneously, adopts the input torque of magnetic elasticity torque sensor measurement, controls the current of magnetorheological brake to control the output torque, utilizes input torque to subtract output torque and the rest torque and obtains the friction force torque to measure its friction coefficient further.

Description

Technical Field

[0001] This utility model relates to the field of measuring the friction coefficient of rolling bearings under high temperature conditions. Background Technology

[0002] Rolling bearings are precision mechanical components that rely on the rolling motion of rolling elements between inner and outer rings to transmit loads and reduce friction. Their core function is to convert the sliding friction between the shaft and the bearing housing into rolling friction, thereby reducing energy loss and wear during mechanical operation and ensuring the precise rotation of the shaft. Nuclear safety is the lifeline of the nuclear energy industry. During reactor operation, rolling bearings are in a complex environment of high temperature, high pressure, high flow rate coolant, and strong radiation, and need to serve in this environment for a long time. Their frictional characteristics directly affect the lifespan and reliability of the equipment.

[0003] Rolling bearings are among the most widely used basic components in modern industry. From small household appliance motors to large automobile wheel hubs, machine tool spindles, and wind turbines, all rely on the support of rolling bearings. In existing technologies, the measurement of bearing friction coefficient under high temperature and high pressure water medium faces two major challenges: First, traditional direct measurement methods rely on high-precision force sensors, but it is difficult to directly use force sensors to simply measure the friction force and thus calculate the friction coefficient in a high temperature and high pressure water environment; second, how to eliminate the influence of inertial force caused by angular acceleration at the beginning of startup.

[0004] Existing research indicates that under high-temperature (≥300℃) water-lubricated conditions, the friction coefficient of bearing materials decreases by approximately 40% compared to dry friction at room temperature. However, wear resistance decreases with increasing temperature. Currently, most testing devices focus on material-level testing and lack the capability to measure complete bearing assemblies under dynamic operating conditions. Furthermore, while similar patents (such as CN109238709A) propose calculating the equivalent friction torque and equivalent friction coefficient of the tested rolling bearing by collecting and processing the angular velocity signal of the spindle or air-bearing spindle monitored by a speed sensor under normal temperature conditions, they do not address the sealing and friction coefficient measurement issues under high-temperature and high-pressure water conditions. Therefore, a new device is needed to measure the friction coefficient of rolling bearings under high-temperature and high-pressure water conditions. Utility Model Content

[0005] Therefore, the purpose of this invention is to provide a device for measuring the friction coefficient of rolling bearings under high temperature conditions, so as to solve the technical problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a device for measuring the friction coefficient of rolling bearings under high temperature conditions, comprising a platform, a magnetorheological brake and a rotary motor being provided on the top of the platform, an output shaft being provided at one end of the magnetorheological brake, an input shaft being provided at one end of the rotary motor, an angular displacement sensor and a torque sensor being installed on the outer wall of the input shaft, a high-temperature and high-pressure reactor body being provided at one end of the output shaft and the input shaft, a water pump and a cold water tank being provided on the top of the high-temperature and high-pressure reactor body, a locking clamp being provided at one end of the high-temperature and high-pressure reactor body, and a bearing body being placed on the top of the locking clamp.

[0007] By adopting the above technical solution, the frictional torque and friction coefficient of rolling bearings can be measured simultaneously through the setting of the output shaft and input shaft. The input torque is measured by a magnetoelastic torque sensor, and the output torque is controlled by controlling the current of the magnetorheological brake. The frictional torque is obtained by subtracting the output torque and the remaining torque (calibrated before the experiment) from the input torque, and then the friction coefficient is determined. The structure is simple and has good overall stability through the setting of water pump, cold water tank and high temperature and high pressure vessel body, and is easy to operate. The input shaft and output shaft are cooled by a dual circulation water cooling system to ensure the heat insulation of the vessel body. The outer ring of the bearing body is clamped by a locking clamp to realize the measurement of the friction coefficient by rotating the inner ring of the bearing while the outer ring remains stationary.

[0008] The present invention is further configured such that a bearing body is provided at one end of the output shaft and the input shaft that are close to each other, and a locking clamp is installed on the outer ring of the bearing body.

[0009] Preferably, the locking clamp clamps the outer ring of the bearing body, allowing the inner ring of the bearing to rotate, which facilitates the measurement of the friction coefficient when the outer ring remains stationary.

[0010] The present invention is further configured such that the locking clamp includes a column, a robotic arm and an extension arm, and a fixing component, and the robotic arm is movably mounted on the outer wall of the column.

[0011] Preferably, the robotic arm and extension arm facilitate clamping of the outer ring of the bearing body, and can also be adjusted according to the size of the bearing body.

[0012] The present invention is further configured such that one end of the robotic arm is provided with an extension arm, and one end of the extension arm is provided with a fixing component.

[0013] Preferably, the stability of the bearing body during the testing process is improved to a certain extent, the shaking of the bearing body is reduced, and the authenticity of the test data is improved.

[0014] The present invention is further configured such that the inner wall of the fixing component is fitted with the outer ring of the bearing body, and the fixing component and the bearing body are engaged, and a bolt is provided at the end of the fixing component away from the bearing body.

[0015] Preferably, the spacing of the fixing components can be adjusted by bolts, which improves the flexibility of the fixing components and the practicality of the device.

[0016] The present invention is further configured such that the magnetorheological brake and the rotary motor are arranged opposite to each other, and the output shaft and the input shaft are located on the same horizontal plane.

[0017] Preferably, the friction torque is obtained by subtracting the output torque and the remaining torque from the input torque, and then the friction coefficient is determined, which effectively improves the automation of the device.

[0018] The present invention is further configured such that the torque sensor is magnetoelastic, and the torque sensor and the rotary motor are arranged opposite to each other.

[0019] Preferably, multiple sensors are used to observe multiple variables, resulting in a high degree of automation and high work efficiency.

[0020] The present invention is further configured such that the locking clamp is located at the lower end of the bearing body, and the bottom of the column is connected to the body of the high-temperature and high-pressure reactor.

[0021] Preferably, the position of the column is limited to improve the stability of the locking clamp during operation.

[0022] The present invention is further configured such that a retaining cup is provided on the top of the bearing body, and the retaining cup is bolted to the body of the high-temperature and high-pressure reactor.

[0023] Preferably, the clamp is positioned to limit the top of the bearing body, thereby applying a radial load.

[0024] In summary, the present invention has the following main advantages: 1. This utility model, through the setting of an output shaft and an input shaft, can simultaneously measure the frictional torque and friction coefficient of a rolling bearing. It uses a magnetoelastic torque sensor to measure the input torque, controls the current of a magnetorheological brake to control the output torque, and obtains the frictional torque by subtracting the output torque and other torques (calibrated before the experiment) from the input torque, and then determines its friction coefficient.

[0025] 2. This utility model has a simple structure with good overall stability and convenient operation due to the setting of a water pump, a cold water tank and a high-temperature and high-pressure reactor body. It adopts a dual-circulation water cooling system to cool the input shaft and the output shaft, ensuring the heat insulation of the reactor body. It uses a locking clamp to clamp the outer ring of the bearing body, so as to realize the friction coefficient measurement by rotating the inner ring of the bearing while keeping the outer ring stationary. Attached Figure Description

[0026] Figure 1This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the locking clamp of this utility model; Figure 3 This is a schematic diagram of the deep groove ball bearing structure of this utility model; Figure 4 For the present utility model Figure 1 Enlarged view of point A in the middle; Figure 5 This is a schematic diagram of the shape of the card holder of this utility model.

[0027] Explanation of reference numerals in the attached figures: 1. Platform; 3. Magnetorheological brake; 4. Output shaft; 6. High-temperature and high-pressure reactor body; 7. Locking clamp; 9. Bearing body; 10. Bucket; 12. Water pump; 13. Cold water tank; 15. Angular displacement sensor; 16. Torque sensor; 17. Input shaft; 18. Rotary motor; 22. Column; 25. Robotic arm; 26. Extension arm; 27. Fixing assembly. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0029] The embodiments of this utility model will be described below based on its overall structure.

[0030] First embodiment: Apparatus for measuring the coefficient of friction of rolling bearings under high temperature conditions, please refer to [reference needed]. Figures 1-5The system includes a platform 1, on the top of which are mounted a magnetorheological brake 3 and a rotary motor 18. One end of the magnetorheological brake 3 has an output shaft 4, and one end of the rotary motor 18 has an input shaft 17. An angular displacement sensor 15 and a torque sensor 16 are mounted on the outer wall of the input shaft 17. A high-temperature, high-pressure reactor body 6 is mounted at one end of the output shaft 4 and the input shaft 17. A water pump 12 and a cold water tank 13 are mounted on the top of the high-temperature, high-pressure reactor body 6. A locking clamp 7 is mounted at one end of the high-temperature, high-pressure reactor body 6, and a bearing body 9 is placed on top of the locking clamp 7. Through the arrangement of the output shaft 4 and the input shaft 17, the friction of the rolling bearing can be measured simultaneously. The friction torque and coefficient of friction are measured by a magnetoelastic torque sensor 16, which measures the input torque. The current of the magnetorheological brake 3 is controlled to control the output torque. The friction torque is obtained by subtracting the output torque and other torques (calibrated before the experiment) from the input torque, and then the coefficient of friction is determined. The structure is simple and has good overall stability and is easy to operate. A dual-circulation water cooling system is used to cool the input shaft 17 and the output shaft 4 to ensure the heat insulation of the vessel body. The outer ring of the bearing body 9 is clamped by a locking clamp 7 to achieve the measurement of the coefficient of friction by rotating the inner ring of the bearing while keeping the outer ring stationary.

[0031] For details regarding the above embodiments, please refer to [link / reference]. Figure 1 , Figure 4 A bearing body 9 is provided at one end of the output shaft 4 and the input shaft 17 that are close to each other. A locking clamp 7 is installed on the outer ring of the bearing body 9. The locking clamp 7 clamps the outer ring of the bearing body 9, so that the inner ring of the bearing can rotate, which facilitates the measurement of the friction coefficient when the outer ring does not move.

[0032] For details regarding the above embodiments, please refer to [link / reference]. Figure 1 , Figure 2 The locking clamp 7 includes a column 22, a robotic arm 25 and an extension arm 26, and a fixing component 27. The robotic arm 25 is movably mounted on the outer wall of the column 22. The robotic arm 25 and the extension arm 26 facilitate clamping the outer ring of the bearing body 9 and can also be adjusted according to the size of the bearing body 9.

[0033] For details regarding the above embodiments, please refer to [link / reference]. Figure 2 One end of the robotic arm 25 is provided with an extension arm 26, and one end of the extension arm 26 is provided with a fixing component 27, which improves the stability of the bearing body 9 during the detection process to a certain extent, reduces the shaking of the bearing body 9, and improves the authenticity of the detection data.

[0034] For details regarding the above embodiments, please refer to [link / reference]. Figure 2 , Figure 3The inner wall of the fixing component 27 is fitted with the outer ring of the bearing body 9, and the fixing component 27 and the bearing body 9 are engaged. A bolt is provided at the end of the fixing component 27 away from the bearing body 9. The spacing of the fixing component 27 can be adjusted by the bolt, which improves the flexibility of the fixing component 27 and the practicality of the device.

[0035] For details regarding the above embodiments, please refer to [link / reference]. Figure 1 , Figure 4 The magnetorheological brake 3 and the rotary motor 18 are arranged opposite each other, and the output shaft 4 and the input shaft 17 are located on the same horizontal plane. The input torque is measured by the magnetoelastic torque sensor 16, and the current of the magnetorheological brake 3 is controlled to control the output torque. The friction torque is obtained by subtracting the output torque and the remaining torque from the input torque, and then the friction coefficient is determined, which effectively improves the automation of the device.

[0036] For details regarding the above embodiments, please refer to [link / reference]. Figure 1 The torque sensor 16 is magnetoelastic, and the torque sensor 16 and the rotary motor 18 are arranged opposite each other. Multiple sensors are used to observe multiple variables, resulting in a high degree of automation and high work efficiency.

[0037] For details regarding the above embodiments, please refer to [link / reference]. Figures 1-4 The locking clamp 7 is located at the lower end of the bearing body 9, and the bottom of the column 22 is connected to the high temperature and high pressure vessel body 6, which limits the position of the column 22 and improves the stability of the locking clamp 7 during operation.

[0038] Second embodiment: Please refer to Figure 5 The difference between Embodiment 2 and Embodiment 1 is that, while retaining the features of Embodiment 1, a retaining cup 10 is added to the top of the bearing body 9, so that the retaining cup 10 limits the top of the bearing body 9 and the W-shaped retaining cup 10 is locked onto the upper ring of the bearing body 9. Loads such as weights are placed in the retaining cup 10, thereby achieving the effect of applying radial load.

[0039] In practical operation, this utility model is as follows: Step 1: Calculate the equivalent friction circle radius r of the bearing (taking a deep groove ball bearing as an example). Then, without installing the bearing body 9, perform torque calibration on the equipment to eliminate interference factors such as the torque transmission structure of the shaft system. The calibrated torque is M_other. Fix the bearing body 9 on the shaft so that the inner ring rotates with the shaft. At the same time, use the locking clamp 7 to fix the outer ring of the bearing to ensure that the friction coefficient can be measured while the inner ring of the bearing rotates and the outer ring does not move. Next, install the W-type chuck 10 above the outer ring of the bearing body 9 and fix it with screws. Apply a radial load F_radial above it. Step 2: Add an appropriate amount of boron-lithium water into the reactor to simulate the reactor environment. Given the experimental temperature, use the ceramic heater inside the reactor to heat the inside of the reactor. At the same time, turn on the water pump 12 and start the dual-circulation water cooling system to prevent the heat from the reactor from being transferred to the torque sensor 16 and the magnetorheological brake 3, which could cause equipment failure. Step 3: After waiting for the temperature inside the reactor to reach the specified temperature (i.e., the service temperature of the bearing in the reactor), first set the current of the magnetorheological brake 3 to control the output torque, then set the parameters of the rotary motor 18, and then start the rotary motor 18 and the magnetorheological brake 3 at the same time to realize the rotation of the input shaft 17, the output shaft 4 and the inner ring of the bearing body 9. At the same time, the torque sensor 16 connected to the rotary motor 18 is used to record the input torque M in real time, and the torque sensor 16 of the magnetorheological brake 3 is used to record the output torque M in real time. The rotation angle θ is also recorded in real time by the angular displacement sensor 15. Step 4: Calculate the angular acceleration α using the measured rotation angle θ. Calculate the inertial torque M_inertia generated by the bearing's own inertia during startup using the formula M_inertia = J_inertiaα. The friction torque is calculated in two stages: the startup stage and the steady-state stage. The torque used is a real-time torque that varies with time. In the steady-state stage, M_friction = M_input - M_output - M_calibration. In the startup stage, the bearing's own inertial torque needs to be considered: M_friction = M_input - M_output - M_calibration - M_inertia. Finally, the friction coefficient μ is calculated using the formula μ = M_friction / F_radial.

[0040] Although embodiments of the present invention have been shown and described, these specific embodiments are merely explanations of the present invention and are not intended to limit the invention. The specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. After reading this specification, those skilled in the art may make modifications, substitutions, and variations to the embodiments as needed without departing from the principles and spirit of the present invention, provided that such modifications, substitutions, and variations are within the scope of the claims of the present invention and are protected by patent law.

Claims

1. An apparatus for determining the coefficient of friction of rolling bearings under high temperature conditions, comprising a platform (1), characterized in that: The platform (1) is equipped with a magnetorheological brake (3) and a rotary motor (18) at the top. The magnetorheological brake (3) is equipped with an output shaft (4) at one end. The rotary motor (18) is equipped with an input shaft (17) at one end. An angular displacement sensor (15) and a torque sensor (16) are installed on the outer wall of the input shaft (17). A high-temperature and high-pressure reactor body (6) is provided at one end of the output shaft (4) and the input shaft (17). A water pump (12) and a cold water tank (13) are provided on the top of the high-temperature and high-pressure reactor body (6). A locking clamp (7) is provided at one end of the high-temperature and high-pressure reactor body (6). A bearing body (9) is placed on the top of the locking clamp (7).

2. The apparatus for determining the friction coefficient of rolling bearings under high-temperature conditions according to claim 1, characterized in that: The output shaft (4) and the input shaft (17) are provided with a bearing body (9) at one end close to each other, and a locking clamp (7) is installed on the outer ring of the bearing body (9).

3. The apparatus for determining the coefficient of friction of rolling bearings under high-temperature conditions according to claim 1, characterized in that: The locking clamp (7) includes a column (22), a robotic arm (25), an extension arm (26), and a fixing component (27), and the robotic arm (25) is movably mounted on the outer wall of the column (22).

4. The apparatus for determining the coefficient of friction of rolling bearings under high-temperature conditions according to claim 3, characterized in that: One end of the robotic arm (25) is provided with an extension arm (26), and one end of the extension arm (26) is provided with a fixing component (27).

5. The apparatus for determining the coefficient of friction of rolling bearings under high-temperature conditions according to claim 3, characterized in that: The inner wall of the fixing component (27) is fitted with the outer ring of the bearing body (9), and the fixing component (27) and the bearing body (9) are engaged. A bolt is provided at the end of the fixing component (27) away from the bearing body (9).

6. The apparatus for determining the coefficient of friction of rolling bearings under high-temperature conditions according to claim 1, characterized in that: The magnetorheological brake (3) and the rotary motor (18) are arranged opposite to each other, and the output shaft (4) and the input shaft (17) are located on the same horizontal plane.

7. The apparatus for determining the coefficient of friction of rolling bearings under high-temperature conditions according to claim 1, characterized in that: The torque sensor (16) is magnetoelastic, and the torque sensor (16) and the rotary motor (18) are arranged opposite to each other.

8. The apparatus for determining the coefficient of friction of rolling bearings under high-temperature conditions according to claim 1, characterized in that: The locking clamp (7) is located at the lower end of the bearing body (9), and the bottom of the column (22) is connected to the high temperature and high pressure vessel body (6).

9. The apparatus for determining the coefficient of friction of rolling bearings under high-temperature conditions according to claim 1, characterized in that: The bearing body (9) is also provided with a hopper (10) on the top, and the hopper (10) is bolted to the high temperature and high pressure vessel body (6).

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