A ceramic roller bearing dynamic stiffness measuring device and measuring method

Abstract

This invention relates to the field of roller bearing technology, and more particularly to a device and method for measuring the dynamic stiffness of ceramic roller bearings. The measuring device includes a base, a radial loading assembly, an axial loading assembly, a bearing mounting fixture, and a measuring assembly. The bearing mounting fixture includes a mounting base and a connecting unit. The mounting base is used to fix the outer ring of the bearing, and the lower part of the connecting unit extends into and engages with the inner ring of the bearing. The radial loading assembly includes a radial loading unit, a radial connecting rod, and a radial reset unit. The axial loading assembly includes an axial loading unit, an axial connecting rod assembly, and an axial reset unit. Both loading units are mounted on the base and drive the same connecting unit via the radial connecting rod and the axial connecting rod assembly, respectively, to simultaneously apply radial and axial loads to the inner ring. The measuring assembly is mounted on the connecting unit and is used to detect the inner ring offset. This device can simulate combined load conditions, and the reset unit ensures consistent starting states for multiple measurements, providing a structural basis for continuous dynamic measurement.

Description

Technical Field

[0001] This invention relates to the field of roller bearing technology, and in particular to a device and method for measuring the dynamic stiffness of ceramic roller bearings. Background Technology

[0002] Currently, the stiffness measurement of ceramic roller bearings mainly follows the traditional static measurement method. This method typically uses hydraulic or mechanical devices to apply a static load only in a single radial or axial direction, and records the deformation under this load using a displacement sensor. Based on this, a single-point static stiffness value is calculated, which can only obtain the instantaneous stiffness data of the bearing under a specific single load condition.

[0003] However, ceramic materials (such as silicon nitride and zirconium oxide) have high elastic modulus and high brittleness, and their stiffness behavior is extremely sensitive to load history and stress state. In actual operation, bearings often bear combined radial and axial loads simultaneously, and their stiffness evolves nonlinearly with changes in load amplitude, loading rate, and number of cycles. Existing unidirectional, single-cycle static measurement methods cannot simulate the real combined working conditions of simultaneous radial and axial loads, nor can they capture the stiffness change law of bearings during continuous variable loads or multiple loading processes, making it difficult to characterize the true dynamic stiffness characteristics of ceramic roller bearings under complex stress states. Summary of the Invention

[0004] (a) Technical problems to be solved In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a dynamic stiffness measuring device and method for ceramic roller bearings, which solves the technical problem that existing ceramic roller bearing stiffness measurements cannot accurately obtain the dynamic stiffness evolution characteristics under composite loads.

[0005] (II) Technical Solution To achieve the above objectives, the main technical solutions adopted by the present invention include: This invention provides a dynamic stiffness measuring device for ceramic roller bearings, including a base, a radial loading assembly, an axial loading assembly, a bearing mounting fixture, and a measuring assembly. The bearing mounting fixture includes a mounting base and a connecting unit. The mounting base is used to fix the outer ring of the ceramic roller bearing, and the lower part of the connecting unit is disposed within the inner ring of the ceramic roller bearing and fits against the inner ring. The radial loading assembly includes a radial loading unit, a radial connecting rod, and a radial reset unit. The axial loading assembly includes an axial loading unit, an axial connecting rod assembly, and an axial reset unit. The radial loading unit and the axial loading unit are disposed on the base. The radial loading unit drives the connecting unit via the radial connecting rod to apply a radial load to the inner ring, and the radial reset unit is used to reset the radial connecting rod. The axial loading unit drives the connecting unit via the axial connecting rod assembly to apply an axial load to the inner ring, and the axial reset unit is used to reset the axial connecting rod assembly. The measuring assembly is disposed on the connecting unit and is used to detect the displacement of the connecting unit to obtain the offset of the inner ring on the connecting unit.

[0006] Preferably, the radial loading unit includes a first drive coil and a first magnet disposed at the end of the radial connecting rod; the first drive coil is disposed on the base, the axis of the first drive coil is horizontally oriented and spaced apart from the first magnet; after the first drive coil is energized, it drives the first magnet to move the radial connecting rod, and the radial load is adjusted by changing the excitation current of the first drive coil.

[0007] Preferably, the radial reset unit includes two elastic units and two reset frames; the two elastic units are respectively disposed on both sides of the radial connecting rod, and the two reset frames are disposed on the base and are disposed in a one-to-one correspondence with the elastic units; the reset frame is provided with two abutting arms that are spaced apart, and the elastic unit is disposed between the two abutting arms.

[0008] Preferably, the axial connecting rod assembly includes a driving rod, a connecting rod, a driven rod, and a hinge seat. The driving rod and the driven rod are respectively hinged to both sides of the connecting rod, and the middle part of the connecting rod is hinged to the hinge seat. One end of the driving rod is connected to the axial loading unit. In the initial state, one end of the driven rod is in contact with the connecting unit. The axial loading unit drives the driving rod to move vertically, and through the swing transmission of the connecting rod, the driven rod moves downward to apply an axial load to the connecting unit.

[0009] Preferably, the axial loading unit includes a second drive coil and a second magnet disposed on the active rod; the second drive coil is disposed on the base, the axis of the second drive coil is vertically oriented and spaced apart from the second magnet; after the second drive coil is energized, it drives the second magnet to move the active rod, and the axial load is adjusted by changing the excitation current of the second drive coil.

[0010] Preferably, the axial reset unit includes a base plate and two arc-shaped elastic elements; the two arc-shaped elastic elements are arranged opposite to each other, and the top end of the arc-shaped elastic elements is connected to the bottom end of the driven rod, and the bottom end of the arc-shaped elastic elements is disposed on the base plate.

[0011] Preferably, the radial loading assembly further includes a first force gauge disposed at the distal end of the radial connecting rod for detecting radial load; the axial loading assembly further includes a second force gauge disposed at the bottom end of the axial reset unit for detecting axial load.

[0012] Preferably, it further includes a driving power supply; the driving power supply is electrically connected to the first driving coil and the second driving coil respectively, and the driving power supply is used to provide excitation current to the first driving coil and the second driving coil respectively, so as to adjust the radial load and the axial load respectively.

[0013] Preferably, the measuring component includes multiple displacement sensors; the multiple displacement sensors are spaced apart in the circumferential direction of the connecting unit to detect the radial and axial displacement of the connecting unit relative to the mounting base.

[0014] This invention also provides a method for measuring the dynamic stiffness of ceramic roller bearings, using the aforementioned dynamic stiffness measuring device for ceramic roller bearings, comprising the following steps: S1. Radial load is applied to the connecting unit through the radial loading unit and the radial connecting rod, and axial load is applied to the connecting unit through the axial loading unit and the axial connecting rod group, so as to apply radial load and axial load to the inner ring simultaneously. S2. The radial and axial displacement of the inner ring is detected by a measuring component set on the connecting unit; S3. After unloading, the radial reset unit resets the radial connecting rod, and the axial reset unit resets the axial connecting rod assembly. S4. At the current position of the roller in the circumferential direction, repeat S1 to S3 at least once to obtain multiple sets of displacement data and corresponding load data; S5. Rotate the outer ring to change the circumferential position of the inner rollers, and repeat S4 in the changed position; S6. Based on the obtained multiple sets of displacement data and corresponding loading load data, calculate the dynamic stiffness value of the ceramic roller bearing under combined load.

[0015] (III) Beneficial Effects The beneficial effects of this invention are: This invention discloses a dynamic stiffness measuring device for ceramic roller bearings, comprising a base, a radial loading assembly, an axial loading assembly, a bearing mounting fixture, and a measuring assembly. The bearing mounting fixture includes a mounting base and a connecting unit. The mounting base is used to fix the outer ring of the ceramic roller bearing. The lower part of the connecting unit is disposed within the inner ring of the ceramic roller bearing and fits against the inner ring. The radial loading assembly includes a radial loading unit, a radial connecting rod, and a radial reset unit. The axial loading assembly includes an axial loading unit, an axial connecting rod assembly, and an axial reset unit. The radial loading unit and the axial loading unit are disposed on the base. The radial loading unit drives the connecting unit via the radial connecting rod to apply a radial load to the inner ring. The radial reset unit is used to reset the radial connecting rod. The axial loading unit drives the connecting unit via the axial connecting rod assembly to apply an axial load to the inner ring. The axial reset unit is used to reset the axial connecting rod assembly. The measuring assembly is disposed on the connecting unit and is used to detect the displacement of the connecting unit to obtain the offset of the inner ring on the connecting unit. By setting the radial loading component and the axial loading component to drive the same connecting unit through the radial connecting rod and the axial connecting rod group respectively, the radial and axial forces on the inner ring of the bearing are applied synchronously. This can simulate the real working condition of bearing bearing a composite load in actual operation. In addition, the setting of the radial reset unit and the axial reset unit can ensure that the connecting rod group can return to the initial position after each loading, ensuring the consistency of the starting state of multiple repeated measurements and providing a structural basis for continuous dynamic measurements.

[0016] The present invention provides a method for measuring the dynamic stiffness of ceramic roller bearings. By comprehensively analyzing force-displacement data from multiple locations and repeated measurements, the dynamic stiffness value is calculated, which can comprehensively and accurately characterize the true dynamic stiffness characteristics of ceramic roller bearings under combined loads. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the dynamic stiffness measuring device for ceramic roller bearings according to the present invention. Figure 2 for Figure 1 Side view; Figure 3 for Figure 2 A longitudinal sectional view; Figure 4 for Figure 1 An enlarged schematic diagram of part A in the middle; Figure 5 for Figure 1 Enlarged schematic diagram of part B.

[0018] [Explanation of Labels in the Attached Image] 1: Base; 2: Radial loading assembly; 21: Radial loading unit; 211: First drive coil; 212: First magnet; 22: Radial connecting rod; 23: Radial reset unit; 231: Elastic unit; 232: Reset frame; 2321: Abutment arm; 24: First force gauge; 3: Axial loading assembly; 31: Axial loading unit; 311: Second drive coil; 312: Second magnet; 32: Axial connecting rod assembly; 321: Driving rod; 322: Connecting rod; 323: Driven rod; 324: Hinge seat; 33: Axial reset unit; 331: Base plate; 332: Arc-shaped elastic element; 34: Second force gauge; 4: Bearing mounting fixture; 41: Mounting base; 42: Connecting unit; 421: Connecting ring; 422: Abutment post; 5: Measurement components; 6: Drive power supply; 7: Ceramic roller bearing; 71: Inner ring; 72: Outer ring; 73: Roller. Detailed Implementation

[0019] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] Example 1 like Figure 1 As shown, this embodiment of the invention provides a dynamic stiffness measuring device for ceramic roller bearings, including a base 1, a radial loading assembly 2, an axial loading assembly 3, a bearing mounting fixture 4, a measuring assembly 5, and a drive power supply 6. The base 1 is used to support and position the various components. The radial loading assembly 2 and the axial loading assembly 3 are both disposed on the base 1. The bearing mounting fixture 4 is disposed on one side of the base 1, and the measuring assembly 5 is disposed on the connecting unit 42 of the bearing mounting fixture 4.

[0021] The bearing mounting fixture 4 includes a mounting base 41 and a connecting unit 42. The mounting base 41 is located on one side of the base 1, and its inner wall mates with the outer circumferential surface of the outer ring 72 of the ceramic roller bearing 7 to be measured, thereby fixing the outer ring 72 so that it remains stationary during measurement. The connecting unit 42 includes an integrally formed abutment post 422 and a connecting ring 421. The connecting ring 421 of the connecting unit 42 is located inside the inner ring 71 of the ceramic roller bearing 7 and fits against the inner ring 71. The abutment post 422 of the connecting unit 42 extends out of the inner ring 71 and is used to mate with the radial loading assembly 2 and the axial loading assembly 3.

[0022] Mounting base 41 fixes the outer ring 72 to keep it stationary. The connecting ring 421 of the connecting unit 42 fits against the inner wall of the inner ring 71. When the radial loading component 2 and the axial loading component 3 drive the abutment post 422 of the connecting unit 42 to move, the connecting unit 42 drives the inner ring 71 to move together, thereby realizing the loading of the bearing inner ring 71.

[0023] The radial loading assembly 2 includes a radial loading unit 21, a radial connecting rod 22, and a radial reset unit 23. The axial loading assembly 3 includes an axial loading unit 31, an axial connecting rod group 32, and an axial reset unit 33. The radial loading unit 21 and the axial loading unit 31 are mounted on the base 1. The radial loading unit 21 drives the connecting unit 42 via the radial connecting rod 22 to apply a radial load to one side of the inner ring 71. The radial reset unit 23 is used to reset the radial connecting rod 22. The axial loading unit 31 drives the connecting unit 42 via the axial connecting rod group 32. The connecting unit 42 transmits the axial force to the inner ring 71 in the form of friction through the contact surface between its outer wall and the inner wall of the inner ring 71 to apply an axial load to the inner ring 71. The axial reset unit 33 is used to reset the axial connecting rod group 32. The measuring component 5 is mounted on the connecting unit 42 to detect the displacement of the connecting unit 42 in order to obtain the offset of the inner ring 71 on the connecting unit 42.

[0024] By setting the radial loading component 2 and the axial loading component 3 to drive the same connecting unit 42 via the radial connecting rod 22 and the axial connecting rod group 32 respectively, the radial and axial forces on the inner ring 71 of the bearing are applied synchronously. After the radial load and the axial load act together on the inner ring 71, the direction of the combined load is at a certain angle with the bearing axis, which can simulate the real working condition of bearing under combined load in actual operation. In addition, the setting of the radial reset unit 23 and the axial reset unit 33 enables the connecting rod group 322 to return to the initial position after each loading, ensuring the consistency of the starting state of multiple repeated measurements and providing a structural basis for continuous dynamic measurements.

[0025] like Figure 3As shown, the radial connecting rod 22 is arranged horizontally, with one end contacting the outer wall of the connecting unit 42 and the other end connected to the radial loading unit 21. The radial connecting rod 22 can reciprocate horizontally. The radial loading unit 21 includes a first driving coil 211 and a first magnet 212 disposed at the end of the radial connecting rod 22. The first driving coil 211 is disposed on the base 1, and its axis is horizontally oriented. The first magnet 212 is fixedly disposed at the end of the radial connecting rod 22, and the first magnet 212 and the first driving coil 211 are arranged opposite each other horizontally with a gap between them. The first driving coil 211 is electrically connected to the driving power supply 6 through a wire. After the first driving coil 211 is energized, it drives the first magnet 212 to move the radial connecting rod 22. The radial load is adjusted by changing the excitation current of the first driving coil 211. To facilitate the installation of the first driving coil 211, the base 1 is provided with a horizontally oriented first positioning post. The first driving coil 211 is sleeved on the first positioning post, and the radial connecting rod 22 is partially disposed on the base 1 and slidably connected to the base 1. After the driving power supply 6 supplies excitation current to the first driving coil 211, an electromagnetic field along its axis is generated inside the first driving coil 211. This electromagnetic field interacts with the permanent magnetic field of the first magnet 212 in space. The electromagnetic polarity generated by the first driving coil 211 repels the first magnet 212. Driven by this electromagnetic force, the first magnet 212 drives the radial connecting rod 22 to move horizontally, thereby pushing the connecting unit 42 and applying a radial load to the inner ring 71. The radial load value can be changed by adjusting the magnitude of the excitation current output by the driving power supply 6 to the first driving coil 211.

[0026] like Figure 4 As shown, the radial reset unit 23 includes two elastic units 231 and two reset frames 232. The two elastic units 231 are respectively disposed on the left and right sides of the radial connecting rod 22. The two reset frames 232 are disposed on the base 1 and are disposed one-to-one with the elastic units 231. The reset frame 232 has two spaced-apart abutment arms 2321, and the elastic unit 231 is disposed between the two abutment arms 2321. To reduce the space occupied by the device, the width of the part of the radial connecting rod 22 where the elastic units 231 are installed is narrowed; the reset frame 232 is integrally formed on the top of the base 1, and the base 1 has an opening at the top for the radial connecting rod 22 to be assembled. Among them, the elastic unit 231 is a gate-shaped structure formed by bending a spring sheet, and the bottom of the gate-shaped structure is fixedly connected to the radial connecting rod 22.

[0027] When the radial loading unit 21 drives the radial connecting rod 22 to load, the elastic unit 231 is compressed and stores elastic potential energy when it abuts against the abutment arm 2321. When the radial loading unit 21 is unloaded, the compressed elastic unit 231 releases the stored elastic potential energy and applies a reverse restoring force to the radial connecting rod 22, causing it to return to its initial position.

[0028] like Figure 1 and Figure 3 As shown, the axial connecting rod assembly 32 includes a driving rod 321, a connecting rod 322, a driven rod 323, and a hinge seat 324. The driving rod 321 and driven rod 323 are hinged to both sides of the connecting rod 322, and the middle part of the connecting rod 322 is hinged to the hinge seat 324. The hinge seat 324 is fixedly mounted on the base 1 or on a mounting plate fixed relative to the base 1. The middle part of the connecting rod 322 is hinged to the hinge seat 324 via a hinge shaft, forming a lever structure. The driving rod 321 and driven rod 323 are hinged to both sides of the connecting rod 322, and one end of the driving rod 321 is connected to the axial loading unit 31. In the initial state, one end of the driven rod 323 is in contact with the connecting unit 42. The axial loading unit 31 drives the driving rod 321 to move vertically, and through the swing transmission of the connecting rod 322, causes the driven rod 323 to move downwards, applying an axial load to the connecting unit 42. Specifically, when the axial loading unit 31 drives the active rod 321 to move upward, the active rod 321 pushes one end of the connecting rod 322 to swing upward, and the connecting rod 322 rotates around the hinge seat 324. Its other end swings downward, driving the driven rod 323 to move downward. The lower end of the driven rod 323 presses against the upper surface of the connecting unit 42, applying a downward axial load to the connecting unit 42. The lever arm lengths at both ends of the connecting rod 322 can be set as needed, and the stroke of the axial load can be amplified by changing the lever arm ratio. This axial connecting rod assembly 32 has a compact structure and a flexible and adjustable transmission ratio. Both the active rod 321 and the driven rod 323 are connected by a hinge, which can adapt to the small displacement of the connecting unit 42 under axial load.

[0029] The driven rod 323 is equipped with a second force gauge 312, which has a certain weight. This weight gives the driven rod 323 a downward gravitational component in its initial state, which helps maintain its vertical posture. To further avoid the direction of axial load application, in the loading sequence of this device, the radial loading unit 21 can act before the axial loading unit 31, forming a constraint in the circumferential direction before axial loading is applied, ensuring that the driven rod 323 moves vertically. Alternatively, a limiting structure can be provided to constrain the movement trajectory of the driven rod 323, ensuring that it only reciprocates vertically.

[0030] like Figure 3As shown, the axial loading unit 31 includes a second drive coil 311 and a second magnet 312 disposed on the drive rod 321. The second drive coil 311 is disposed on the base 1, with its axis vertically oriented. The second magnet 312 is fixedly disposed on the drive rod 321, with the second magnet 312 and the second drive coil 311 arranged vertically opposite each other and with a gap between them. The second drive coil 311 is electrically connected to the drive power supply 6 via a wire. After the second drive coil 311 is energized, it drives the second magnet 312 to move the drive rod 321. The axial load is adjusted by changing the excitation current of the second drive coil 311. Figure 3 As shown, to facilitate the installation of the second drive coil 311, a vertically oriented second positioning post is provided on the base 1. The second drive coil 311 is sleeved on the second positioning post. To guide the active rod 321, a guide post is provided. The second positioning post and the guide post are coaxially and spaced apart. The second drive coil 311 is located inside the guide post. The lower end of the active rod 321 is a sleeve structure. The sleeve structure is sleeved on the outside of the guide post, and its interior forms a receiving space. The second magnet 312 is located at the top of the receiving space, and the lower end face of the second magnet 312 is opposite to the upper end face of the second drive coil 311. A gap is left between the second magnet 312 and the second drive coil 311 in the vertical direction.

[0031] The electromagnetic drive principle of the axial loading unit 31 is the same as that of the radial loading unit 21: the second magnet 312, driven by the electromagnetic force of the second drive coil 311, drives the active rod 321 to move vertically. After lever transmission via the axial connecting rod group 32, the driven rod 323 applies an axial load to the connecting unit 42. The axial load value is changed by adjusting the magnitude of the excitation current output from the drive power supply 6 to the second drive coil 311.

[0032] like Figure 5 As shown, the axial reset unit 33 includes a base plate 331 and two arc-shaped elastic elements 332. The two arc-shaped elastic elements 332 are arranged relatively apart, and the top end of the arc-shaped elastic element 332 is connected to the bottom end of the driven rod 323. The bottom end of the arc-shaped elastic element 332 is disposed on the base plate 331. The base plate 331 can directly contact the top end of the connecting unit 42. The arc-shaped elastic element 332 can be an arc-shaped spring sheet. When the axial loading unit 31 drives the driven rod 323 downward via the connecting rod 322, the driven rod 323 compresses the arc-shaped elastic element 332, causing the arc-shaped elastic element 332 to undergo elastic deformation and store elastic potential energy. When the axial loading unit 31 is unloaded, the arc-shaped elastic element 332 releases the stored elastic potential energy, applying an upward restoring force to the driven rod 323, causing the driven rod 323 to return to its initial position.

[0033] like Figure 3As shown, the radial loading assembly 2 also includes a first force gauge 24, which is disposed at the distal end of the radial connecting rod 22 and is used to detect radial loads. That is, the first force gauge 24 can contact the connecting unit 42. The axial loading assembly 3 also includes a second force gauge 34, which is disposed at the bottom end of the axial reset unit 33 and is used to detect axial loads.

[0034] In this embodiment, the driving power supply 6 is a dual-channel independent output power supply, which contains two independent current regulation modules, respectively connected to the first driving coil 211 and the second driving coil 311. Each regulation module can independently adjust the amplitude and direction of the output current, thereby independently controlling the magnitude and direction of the radial load and the axial load.

[0035] like Figure 1 As shown, the measuring component 5 includes multiple displacement sensors, which are spaced apart around the circumference of the connecting unit 42 to detect the radial and axial displacements of the connecting unit 42 relative to the mounting base 41. The displacement sensors can be eddy current displacement sensors, laser displacement sensors, or LVDT displacement sensors. The probes of the displacement sensors are aligned with the inner wall of the mounting base 41. When the connecting unit 42 is displaced under radial or axial load, the sensor outputs an electrical signal proportional to the displacement. The multiple sensors, spaced apart around the circumference of the connecting unit 42, can simultaneously detect the displacement components of the connecting unit 42 in different directions. After synthesis and calculation, the complete displacement vector of the connecting unit 42 in space can be obtained.

[0036] In dynamic stiffness measurement, stiffness characterizes the bearing's ability to resist deformation. Its physical meaning is the correspondence between the load applied to the bearing and the displacement of the inner ring 71 caused by that load: under the same load conditions, the smaller the bearing displacement, the greater the stiffness; conversely, the larger the displacement, the smaller the stiffness. Based on this principle, this embodiment uses the first force gauge 24 and the second force gauge 34 to collect the values ​​of radial and axial loads respectively, and the measuring component 5 synchronously acquires the displacement of the inner ring 71 in the corresponding direction under the load, thus obtaining the bearing's stiffness response data under specific load conditions. Since this device can continuously apply loads of different amplitudes and measure multiple times at the same roller 73 position, a complete data sequence corresponding to the load and displacement can be obtained, thereby obtaining the dynamic characteristics of stiffness changing with load.

[0037] Example 2 This invention also provides a method for measuring the dynamic stiffness of ceramic roller bearings, using the dynamic stiffness measuring device for ceramic roller bearings 7 in Embodiment 1, and includes the following steps: S1. A radial load is applied to the connecting unit 42 via the radial loading unit 21 and the radial connecting rod 22, while an axial load is applied to the connecting unit 42 via the axial loading unit 31 and the axial connecting rod group 32, so as to simultaneously apply radial and axial loads to the inner ring 71. The driving power supply 6 outputs excitation current to the first driving coil 211 and the second driving coil 311 respectively. The electromagnetic force generated by the first driving coil 211 drives the first magnet 212 to move the radial connecting rod 22 horizontally, applying radial force to the connecting unit 42. Simultaneously, the electromagnetic force generated by the second driving coil 311 drives the second magnet 312 to move the driving rod 321 vertically, and after lever transmission, the driven rod 323 applies axial force to the connecting unit 42. The two loading paths are performed simultaneously, achieving synchronous radial and axial force application to the bearing inner ring 71, simulating the real working condition of bearing under combined loads during actual operation.

[0038] S2. The radial and axial displacement of the inner ring 71 is detected by the measuring component 5 installed on the connecting unit 42. Multiple displacement sensors in the measuring component 5 detect the displacement of the connecting unit 42 in space in real time. Since the connecting unit 42 is in contact with the inner ring 71, the displacement of the connecting unit 42 is the displacement of the inner ring 71. The displacement signals output by the sensors and the force signals output by the first force gauge 24 and the second force gauge 34 in step S1 are synchronously acquired by the data acquisition system.

[0039] S3. After unloading, the radial reset unit 23 resets the radial connecting rod 22, and the axial reset unit 33 resets the axial connecting rod assembly 32. The drive power supply 6 cuts off the excitation current of the first drive coil 211 and the second drive coil 311, and the electromagnetic force disappears. The radial reset unit 23 and the axial reset unit 33 release elastic potential energy. After the reset is completed, the entire loading system returns to its initial state, providing consistent starting conditions for the next loading measurement.

[0040] S4. With the current circumferential position of roller 73, repeat steps S1 to S3 at least once to obtain multiple sets of displacement data and corresponding load data. While maintaining the relative position of roller 73 to the load direction, obtain multiple force-displacement data pairs through repeated loading, measurement, and reset cycles. The data from multiple repeated measurements can be used for statistical analysis to eliminate the influence of random errors, and can also be used to observe whether the bearing stiffness at the same location changes with the number of loading cycles.

[0041] S5. Rotate the outer ring 72 to change the circumferential position of the rollers 73 inside, and repeat S4 in the changed position. Since the rollers 73 are uniformly or regularly distributed in the circumferential direction of the bearing, the relative angles between different rollers 73 and the load application direction are different. By rotating the outer ring 72 to change the circumferential position of the rollers 73 and measuring again, the stiffness data of the bearing at different roller positions 73 can be obtained, reflecting the circumferential stiffness distribution of the bearing. By performing step S4 at different roller positions 73, a complete measurement dataset containing the position information of all rollers 73 can be obtained.

[0042] S6. Based on the obtained multiple sets of displacement data and corresponding loading load data, calculate the dynamic stiffness value of the ceramic roller bearing 7 under combined load.

[0043] By applying forces simultaneously in the radial and axial directions, direct measurement of dynamic stiffness under combined loads is achieved, overcoming the limitation of existing unidirectional, single-time static measurements that cannot characterize combined stress states. Repeated measurements at the same roller 73 position allow for the acquisition of stiffness data at that position under continuous loading and unloading cycles, revealing the influence of load history on the stiffness of the ceramic roller bearing 7. By rotating the outer ring 72 to change the position of roller 73 and then repeating the measurement, comprehensive measurements of different roller 73 positions along the bearing circumferential direction are achieved, reflecting the impact of roller 73 position differences on the bearing stiffness distribution. This measurement method integrates force-displacement data from multiple positions and repeated measurements to calculate the dynamic stiffness value, and the results comprehensively and accurately characterize the true dynamic stiffness characteristics of the ceramic roller bearing 7 under combined loads.

[0044] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0045] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0046] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "over," or "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," or "beneath" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0047] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0048] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A device for measuring the dynamic stiffness of ceramic roller bearings, characterized in that, Includes a base, radial loading assembly, axial loading assembly, bearing mounting fixtures, and measuring components; The bearing mounting fixture includes a mounting base and a connecting unit. The mounting base is used to fix the outer ring of the ceramic roller bearing, and the lower part of the connecting unit is disposed inside the inner ring of the ceramic roller bearing and fits against the inner ring. The radial loading assembly includes a radial loading unit, a radial connecting rod, and a radial reset unit; the axial loading assembly includes an axial loading unit, an axial connecting rod group, and an axial reset unit; the radial loading unit and the axial loading unit are disposed on the base. The radial loading unit drives the connecting unit via the radial connecting rod to apply a radial load to the inner ring, and the radial reset unit is used to reset the radial connecting rod; The axial loading unit drives the connecting unit via the axial connecting rod assembly to apply an axial load to the inner ring, and the axial reset unit is used to reset the axial connecting rod assembly. The measuring component is disposed on the connecting unit and is used to detect the displacement of the connecting unit in order to obtain the offset of the inner ring on the connecting unit.

2. The dynamic stiffness measuring device for ceramic roller bearings as described in claim 1, characterized in that: The radial loading unit includes a first drive coil and a first magnet disposed at the end of the radial connecting rod; The first driving coil is disposed on the base, and the axis of the first driving coil is horizontally oriented and spaced apart from the first magnet; When the first drive coil is energized, it drives the first magnet to move the radial connecting rod. The radial load is adjusted by changing the excitation current of the first drive coil.

3. The dynamic stiffness measuring device for ceramic roller bearings as described in claim 2, characterized in that: The radial reset unit includes two elastic units and two reset frames; The two elastic units are respectively disposed on both sides of the radial connecting rod, and the two reset frames are disposed on the base and are disposed in a one-to-one correspondence with the elastic units; The reset frame has two abutment arms spaced apart, and the elastic unit is disposed between the two abutment arms.

4. The dynamic stiffness measuring device for ceramic roller bearings as described in claim 2, characterized in that: The axial connecting rod assembly includes a driving rod, a connecting rod, a driven rod, and a hinge seat. The driving rod and the driven rod are respectively hinged to both sides of the connecting rod. The middle part of the connecting rod is hinged to the hinge seat. One end of the driving rod is connected to the axial loading unit. In the initial state, one end of the driven rod is in contact with the connecting unit; The axial loading unit drives the active rod to move vertically, and through the swing transmission of the connecting rod, the driven rod moves downward to apply an axial load to the connecting unit.

5. The dynamic stiffness measuring device for ceramic roller bearings as described in claim 4, characterized in that: The axial loading unit includes a second drive coil and a second magnet disposed on the active rod; The second driving coil is disposed on the base, and the axis of the second driving coil is vertically oriented and spaced apart from the second magnet; When the second drive coil is energized, it drives the second magnet to move the active rod. The axial load is adjusted by changing the excitation current of the second drive coil.

6. The dynamic stiffness measuring device for ceramic roller bearings as described in claim 4, characterized in that: The axial reset unit includes a base plate and two arc-shaped elastic elements; The two arc-shaped elastic elements are arranged opposite each other, and the top end of the arc-shaped elastic element is connected to the bottom end of the driven rod, and the bottom end of the arc-shaped elastic element is disposed on the base plate.

7. The dynamic stiffness measuring device for ceramic roller bearings as described in claim 1, characterized in that: The radial loading assembly further includes a first force gauge, which is disposed at the distal end of the radial connecting rod and is used to detect radial load. The axial loading assembly also includes a second force gauge, which is disposed at the bottom end of the axial reset unit and is used to detect axial load.

8. The dynamic stiffness measuring device for ceramic roller bearings as described in claim 5, characterized in that: It also includes the drive power supply; The driving power supply is electrically connected to the first driving coil and the second driving coil respectively. The driving power supply is used to provide excitation current to the first driving coil and the second driving coil respectively, so as to adjust the radial load and axial load respectively.

9. The dynamic stiffness measuring device for ceramic roller bearings as described in claim 1, characterized in that: The measurement component includes multiple displacement sensors; Multiple displacement sensors are spaced apart on the circumferential direction of the connecting unit to detect the radial and axial displacement of the connecting unit relative to the mounting base.

10. A method for measuring the dynamic stiffness of ceramic roller bearings, employing the dynamic stiffness measuring device for ceramic roller bearings as described in any one of claims 1-9, characterized in that, Includes the following steps: S1. A radial load is applied to the connecting unit through the radial loading unit via the radial connecting rod, and an axial load is applied to the connecting unit through the axial loading unit via the axial connecting rod group, so as to apply radial and axial loads to the inner ring simultaneously. S2. The radial and axial displacement of the inner ring is detected by a measuring component disposed on the connecting unit; S3. After unloading, the radial reset unit resets the radial connecting rod, and the axial reset unit resets the axial connecting rod assembly. S4. At the current position of the roller in the circumferential direction, repeat S1 to S3 at least once to obtain multiple sets of displacement data and corresponding load data; S5. Rotate the outer ring to change the circumferential position of the rollers inside it, and repeat S4 in the changed position; S6. Based on the obtained multiple sets of displacement data and corresponding loading load data, calculate the dynamic stiffness value of the ceramic roller bearing under combined load.

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