A kind of hub bearing stiffness test tool based on real vehicle steering knuckle

Abstract

The present application relates to the technical field of bearing detection, in particular to a kind of hub bearing rigidity test tool based on real vehicle steering knuckle, including tooling table, it is equipped with tooling assembly on it, it further includes loading flange plate, universal joint, it is arranged in the center of the loading flange plate, axial loading rod, it is along the axial direction of the loading flange plate and is arranged, radial loading rod, it is along the radial direction of the loading flange plate and is arranged, vertical slide rail and horizontal slide rail, the vertical slide rail is fixed to the tooling table, the vertical slide rail is slidably provided with sliding frame for installing the axial loading rod, the horizontal slide rail is fixed to the sliding frame, the radial loading rod is slidably arranged on the horizontal slide rail.The present application is rigidly fixed to tooling table by real vehicle steering knuckle, and is rigidly connected with hub bearing using loading flange plate, in combination with universal joint, so that axial load is stably transmitted and additional bending moment generated due to the inclination of flange plate can be released.

Description

Technical Field

[0001] This invention relates to the field of bearing testing technology, specifically to a wheel hub bearing stiffness testing fixture based on a real vehicle steering knuckle. Background Technology

[0002] As a critical rotating support component between the vehicle suspension and the wheel, wheel bearings must withstand both radial and axial loads. Currently, wheel bearing stiffness testing directly applies loads to the actual vehicle steering knuckle using a rigid indenter. However, existing wheel bearing stiffness testing fixtures mostly use simulated jigs, which cannot utilize complete actual vehicle steering knuckles, making it difficult to accurately reproduce the load path and boundary conditions, resulting in test results that deviate from reality.

[0003] The currently published Chinese patent publication number CN218496413U discloses a special tooling for testing the stiffness of automotive wheel hub bearings. This tooling includes a worktable and tooling components mounted on the worktable. The tooling components include several L-shaped positioning plates, a vehicle steering knuckle, and a vehicle brake disc. The L-shaped positioning plates are detachably fixed to the worktable. The vehicle steering knuckle is supported by the L-shaped positioning plates and locked to each L-shaped positioning plate by pins. The top of the vehicle steering knuckle has a mounting groove for mounting the wheel hub bearing to be tested. The vehicle brake disc covers the flange surface of the wheel hub bearing to be tested and is locked to it.

[0004] According to the aforementioned patent, the stiffness test can be conducted by installing the actual vehicle steering knuckle into a tooling, adjusting the L-shaped positioning plate and locking it with pins, installing the wheel hub bearing and brake disc to be tested, fixing them with bolts, and then installing the actual vehicle wheel rim. An axial force is then applied at the radius of the wheel rim from the loading end. However, the loading force is applied at the radius of the wheel rim, which is an eccentric loading, and will inevitably generate an additional bending moment. It is impossible to achieve pure axial or pure radial force application, resulting in distortion of the stiffness measurement.

[0005] Therefore, there is a need for a wheel hub bearing stiffness testing fixture based on a real vehicle steering knuckle, which can directly apply the loading force to the rotation center of the wheel hub bearing, effectively eliminate the interference of additional bending moment, and thus truly and accurately measure the stiffness characteristics of the wheel hub bearing under the vehicle's operating conditions. Summary of the Invention

[0006] To address the problems existing in the prior art, a wheel hub bearing stiffness testing fixture based on a real vehicle steering knuckle is provided. By rigidly fixing the real vehicle steering knuckle to the fixture table and rigidly connecting it to the wheel hub bearing using a loading flange, combined with a universal joint, the axial load is smoothly transmitted and the additional bending moment caused by the tilt of the flange is released.

[0007] To address the problems of existing technologies, this invention provides a wheel hub bearing stiffness testing fixture based on a real vehicle steering knuckle. The fixture includes a tooling table with a tooling assembly for mounting and rigidly fixing a real vehicle steering knuckle with the wheel hub bearing to be tested. It also includes a loading flange rigidly connected to the end face of the wheel hub bearing through the original wheel bolt holes. The loading flange is coaxial with the wheel hub bearing. A universal joint is located at the center of the loading flange. An axial loading rod is arranged along the axial direction of the loading flange, with one end connected to the universal joint for applying axial load. A radial loading rod is arranged radially along the loading flange, with one end contacting the side of the loading flange for applying radial load. A vertical slide rail and a horizontal slide rail are also included. The vertical slide rail is fixed to the tooling table, and a sliding frame for mounting the axial loading rod is slidably mounted on the vertical slide rail. The horizontal slide rail is fixed to the sliding frame, and the radial loading rod is slidably mounted on the horizontal slide rail.

[0008] Preferably, the universal joint includes an axial ball socket and an axial ball head. The axial ball socket is fixedly disposed at the center of the loading flange, and the axial ball head is fixedly connected to the end of the axial loading rod. The axial ball head is embedded in the axial ball socket, and a surface contact fit is formed between the axial ball socket and the axial ball head.

[0009] Preferably, the loading flange has an adaptive structure on the side corresponding to the radial loading rod to release the additional bending moment caused by the loading flange tilting around the axial ball head center.

[0010] Preferably, the adaptive structure is a radial ball socket fixedly disposed on the side of the loading flange, and the end of the radial loading rod is provided with a radial ball head that mates with the radial ball socket.

[0011] Preferably, the radial ball head is fitted with a rubber sleeve embedded in the radial ball socket, which is used to elastically adapt to and release additional bending moment when the loading flange tilts around the axial ball head center.

[0012] Preferably, a limiting sleeve is fitted on the axial loading rod, and an elastic limiting pad is provided at the lower end of the limiting sleeve to provide buffering and limit the deflection angle when the axial ball socket is tilted.

[0013] Preferably, a plurality of disc springs are provided between the limiting sleeve and the axial ball socket, which are arranged coaxially with the axial loading rod to provide axial elastic preload.

[0014] Preferably, the limiting sleeve is axially movable along the axial loading rod, the sliding frame is provided with a slide seat for fixing the axial loading rod, and the slide seat is provided with a gap adjustment component that is throttle-connected to the limiting sleeve for adjusting the limiting gap between the elastic limiting pad and the axial ball socket.

[0015] Preferably, the spacing adjustment assembly includes a sliding sleeve sleeved on the axial loading rod and fixed to the upper end of the limiting sleeve. The sliding seat has an air cavity, the upper end of the sliding sleeve is slidably inserted into the air cavity and is provided with a piston, and the side of the sliding seat has an air port communicating with the air cavity.

[0016] Preferably, multiple displacement sensors are evenly distributed on the slide along the circumferential direction of the axial loading rod, and the limiting sleeve is provided with a sensing point corresponding to each displacement sensor, for real-time monitoring of the limiting gap and the skew state between the elastic limiting pad and the axial ball socket.

[0017] The advantages of this application compared to the prior art are: 1. This invention rigidly fixes the actual vehicle steering knuckle to the tooling table and uses the loading flange to rigidly connect to the wheel hub bearing through the original vehicle bolt holes. Combined with the surface contact universal joint composed of axial ball head and axial ball socket, the axial load is smoothly transmitted and the additional bending moment caused by the tilt of the flange can be released.

[0018] Simultaneously, the vertical slide rail drives the sliding frame and the horizontal slide rail to rise and fall synchronously, ensuring that the radial loading rod remains in contact with the side of the flange during axial loading, and that radial loads can be applied independently when needed. Under realistic test conditions, this achieves independent and precise application of axial and radial loads, effectively guaranteeing high fidelity in wheel hub bearing stiffness testing.

[0019] 2. The present invention provides an adaptive structure consisting of a radial ball socket, a radial ball head, and a rubber sleeve on the side of the loading flange. This structure enables the radial loading rod to achieve flexible contact when the loading flange is slightly tilted around the center of the axial ball head. This is achieved through the slight rotation of the radial ball socket relative to the radial ball head and the elastic deformation of the rubber sleeve, effectively releasing the additional bending moment.

[0020] Meanwhile, the loading flange adopts coaxial stacked discs and is rigidly fixed to the radial ball socket by two fixing plates, which improves its resistance to loosening and deformation, and ensures that the mating pair is stable and reliable when radial load is applied, thereby ensuring that only the real radial force is transmitted and improving the accuracy of the radial stiffness test of the wheel hub bearing.

[0021] 3. This invention forms a protective structure that combines preload, buffering, and flexible limiting functions by setting an adjustable limiting sleeve on the axial loading rod, configuring an elastic limiting pad at its lower end, and arranging a coaxial disc spring between the limiting sleeve and the axial ball socket. When the loading flange tilts excessively due to deformation of the wheel hub bearing, the elastic limiting pad contacts the axial ball socket to provide buffering and limit excessive deflection, while the disc spring maintains the alignment preload and slight tilt compliance under normal operating conditions.

[0022] Before testing, the optimal limit clearance can be preset for different wheel hub bearing stiffness or load conditions. This ensures that the working bending moment can be released freely while preventing abnormal collisions, thus ensuring the accuracy and safety of the axial stiffness test. Attached Figure Description

[0023] Figure 1 This is a three-dimensional structural schematic diagram of a wheel hub bearing stiffness testing fixture based on a real vehicle steering knuckle according to the present invention.

[0024] Figure 2 This is a three-dimensional exploded view of a wheel hub bearing stiffness testing fixture based on a real vehicle steering knuckle, according to the present invention.

[0025] Figure 3 This is a partial three-dimensional structural schematic diagram of a wheel hub bearing stiffness testing fixture based on a real vehicle steering knuckle according to the present invention.

[0026] Figure 4 This is a partial three-dimensional cross-sectional view of a wheel hub bearing stiffness testing fixture based on a real vehicle steering knuckle according to the present invention.

[0027] Figure 5 This is a partial planar sectional view of a wheel hub bearing stiffness testing fixture based on a real vehicle steering knuckle according to the present invention.

[0028] Figure 6 This is a three-dimensional exploded view of the loading flange and the wheel hub bearing of a wheel hub bearing stiffness testing fixture based on a real vehicle steering knuckle, as presented in the first perspective of the present invention.

[0029] Figure 7 This is a three-dimensional exploded view of the loading flange and the wheel hub bearing of a wheel hub bearing stiffness testing fixture based on a real vehicle steering knuckle, as shown in the second perspective.

[0030] Figure 8 This is a planar sectional view of the axial loading rod and loading flange of a wheel hub bearing stiffness testing fixture based on a real vehicle steering knuckle according to the present invention.

[0031] Figure 9 This is a three-dimensional structural cross-sectional view of the axial loading rod and loading flange of a wheel hub bearing stiffness testing fixture based on a real vehicle steering knuckle according to the present invention.

[0032] Figure 10 This is an exploded three-dimensional structural diagram of a wheel hub bearing and a real vehicle steering knuckle, which is part of a wheel hub bearing stiffness testing fixture based on a real vehicle steering knuckle according to the present invention.

[0033] The following are the labels in the diagram: 1. Tooling table; 11. Tooling assembly; 12. Vertical slide rail; 121. Sliding frame; 122. Slide seat; 1221. Air chamber; 1222. Air port; 123. Displacement sensor; 124. Sensing point; 13. Transverse slide rail; 2. Wheel hub bearing; 21. Fastening bolt; 3. Actual vehicle steering knuckle; 4. Loading flange; 5. Universal joint; 51. Axial ball socket; 52. Axial ball head; 6. Axial loading rod; 61. Limit sleeve; 611. Sliding sleeve; 612. Piston; 62. Elastic limit pad; 63. Disc spring; 7. Radial loading rod; 71. Adaptive structure; 711. Radial ball socket; 712. Radial ball head; 713. Rubber sleeve. Detailed Implementation

[0034] To further understand the features, technical means, and specific objectives and functions achieved by the present invention, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0035] See Figures 1 to 7 and Figure 10 As shown, a wheel hub bearing stiffness testing fixture based on a real vehicle steering knuckle includes a fixture table 1, on which a fixture assembly 11 for mounting and rigidly fixing a real vehicle steering knuckle 3 with a wheel hub bearing 2 to be tested is provided. It also includes a loading flange 4, rigidly connected to the end face of the wheel hub bearing 2 through the original wheel bolt holes. The loading flange 4 is coaxial with the wheel hub bearing 2. A universal joint 5 is located at the center of the loading flange 4. An axial loading rod 6 is arranged along the axial direction of the loading flange 4, one end of which is connected to the universal joint 5 for applying axial load. A radial loading rod 7 is arranged along the radial direction of the loading flange 4, one end of which contacts the side of the loading flange 4 for applying radial load. The vertical slide rail 12 and the horizontal slide rail 13 are provided. The vertical slide rail 12 is fixed to the tooling table 1. A sliding frame 121 for mounting the axial loading rod 6 is slidably provided on the vertical slide rail 12. The horizontal slide rail 13 is fixed to the sliding frame 121. The radial loading rod 7 is slidably disposed on the horizontal slide rail 13.

[0036] The loading flange 4 and the hub bearing 2 are connected by fastening bolts 21.

[0037] The axial loading rod 6 and the radial loading rod 7 are driven by servo actuators, such as hydraulic rods.

[0038] During the test, the complete vehicle steering knuckle 3, equipped with the wheel hub bearing 2 to be tested, was first installed and rigidly fixed on the tooling assembly 11 fixed on the tooling table 1, ensuring that the steering knuckle remained stable during subsequent loading. Then, the loading flange 4 was connected to the end face of the wheel hub bearing 2, which was already installed on the top of the steering knuckle, through the original wheel bolt holes, and rigidly connected using fastening bolts 21, ensuring that the loading flange 4 and the wheel hub bearing 2 were strictly coaxial, thus replicating the actual assembly relationship between the wheel hub and bearing in the entire vehicle.

[0039] After the above fixing is completed, when the servo actuator drives the sliding frame 121 to move downward along the vertical slide rail 12, the axial loading rod 6 moves accordingly, transmitting the pure axial load to the center of the loading flange 4 through the universal joint 5, and then acting on the hub bearing 2. Due to the presence of the universal joint 5, even if the loading flange 4 tilts slightly due to the elastic deformation of the hub bearing 2, the additional bending moment can be released through the relative rotation inside the universal joint 5, ensuring that the applied force is the real axial force.

[0040] Meanwhile, the transverse slide rail 13 rises and falls along the vertical slide rail 12 together with the sliding frame 121. When a radial stiffness test is required, the radial loading rod 7 is pushed along the transverse slide rail 13 toward the side of the loading flange 4 under the drive of the servo actuator to apply a radial load. During axial loading, as the transverse slide rail 13 rises and falls synchronously with the sliding frame 121, the radial loading rod 7 also moves up and down accordingly, always maintaining contact with the side of the loading flange 4.

[0041] The entire structure achieves independent control and coordinated movement of axial and radial loading paths through the orthogonal arrangement of vertical slide rail 12 and horizontal slide rail 13. At the same time, relying on the fastening bolts 21 between the loading flange 4 and the wheel hub bearing 2, a high-fidelity wheel hub bearing 2 stiffness test is completed while retaining the actual vehicle steering knuckle 3.

[0042] See Figures 4 to 9 As shown, the universal joint 5 includes an axial ball socket 51 and an axial ball head 52. The axial ball socket 51 is fixedly disposed at the center of the loading flange 4. The axial ball head 52 is fixedly connected to the end of the axial loading rod 6. The axial ball head 52 is embedded in the axial ball socket 51, and a surface contact mating pair is formed between the axial ball socket 51 and the axial ball head 52.

[0043] During the test, the axial loading rod 6 moves vertically, and its axial ball end 52 is always embedded inside the axial ball socket 51. The load is smoothly transferred to the loading flange 4 through the surface contact fit formed between the two. Due to the surface contact fit, the contact area is increased, the local contact stress is reduced, and the structural durability is improved.

[0044] More importantly, when the hub bearing 2 undergoes slight elastic deformation under load, causing the loading flange 4 to tilt slightly around its center, a small relative rotation can occur between the axial ball joint 52 and the axial ball socket 51, effectively releasing the additional bending moment generated as a result. This ensures that the load applied to the hub bearing 2 always remains a pure axial force, avoiding the introduction of inaccurate stiffness responses due to tooling constraints, thereby improving the authenticity and repeatability of the stiffness test results.

[0045] See Figures 4 to 7 As shown, the loading flange 4 is provided with an adaptive structure 71 on the side corresponding to the radial loading rod 7, which is used to release the additional bending moment caused by the loading flange 4 tilting around the center of the axial ball head 52.

[0046] During the test, when an axial load is applied to the hub bearing 2, due to the inherent stiffness characteristics of the hub bearing 2 or minor assembly deviations, the loading flange 4 may tilt slightly around the center of the axial ball joint 52. If the radial loading rod 7 is in rigid contact with the side of the loading flange 4, this tilt will cause a local constraint reaction force at the contact point, thereby introducing an unreal additional bending moment and interfering with the accurate measurement of radial stiffness. To address this, the adaptive structure 71 can actively adapt to the attitude change of the loading flange 4 when it tilts, avoiding the formation of rigid constraints.

[0047] Specifically, when the loading flange 4 deflects around the center of the axial ball joint 52 under load, the adaptive structure 71 allows the end of the radial loading rod 7 to maintain flexible contact with it rather than being forcibly pressed, thereby effectively releasing the additional bending moment caused by tilting. This ensures that only the true radial force is transmitted during radial loading, improving the accuracy and reliability of the radial stiffness test of the hub bearing 2, while protecting the radial loading rod 7 from impact or overload damage.

[0048] See Figures 4 to 7 As shown, the adaptive structure 71 is a radial ball socket 711 fixedly disposed on the side of the loading flange 4, and the end of the radial loading rod 7 is provided with a radial ball head 712 that cooperates with the radial ball socket 711.

[0049] The loading flange 4 is composed of two coaxially stacked discs. The radial ball socket 711 is provided with two fixing plates. One fixing plate is sandwiched between the upper and lower discs, and the other fixing plate is fixed to the top of the upper disc to enhance the connection rigidity of the radial ball socket 711 and prevent loosening or local deformation when radial load is applied.

[0050] During the radial stiffness test, the radial ball head 712 at the end of the radial loading rod 7 forms a mating pair with the radial ball socket 711 fixed to the side of the loading flange 4. When the loading flange 4 tilts slightly around the center of the axial ball head 52 due to axial load or its own deformation, the radial ball head 712 can rotate slightly within the radial ball socket 711, effectively releasing the additional bending moment generated thereby and avoiding test distortion caused by rigid constraints.

[0051] See Figures 4 to 7 As shown, a rubber sleeve 713 is fitted on the radial ball head 712 and embedded in the radial ball socket 711, which is used to elastically adapt to and release additional bending moment when the loading flange 4 tilts around the center of the axial ball head 52.

[0052] During the test, when the loading flange 4 tilts slightly around the center of the axial ball head 52 due to the deformation of the hub bearing 2 under load, the radial ball socket 711 will deflect relative to the radial ball head 712.

[0053] At this point, the rubber sleeve 713 undergoes controlled compression deformation in the local contact area, flexibly adapting to the tilting displacement of the loading flange 4 and avoiding rigid impact. This not only effectively absorbs the instantaneous impact caused by the change in posture but also releases the additional bending moment, ensuring that only pure radial force is transmitted to the hub bearing 2, thus improving the authenticity and reliability of the stiffness test.

[0054] See Figure 4 , Figure 5 , Figure 8 and Figure 9 As shown, a limiting sleeve 61 is fitted on the axial loading rod 6, and an elastic limiting pad 62 is provided at the lower end of the limiting sleeve 61 to provide buffering and limit the deflection angle when the axial ball socket 51 is tilted.

[0055] During the axial stiffness test, when the loading flange 4 tilts around the center of the axial ball joint 52 due to the deformation of the hub bearing 2, if the deflection angle is too large, the edge of the axial ball joint 51 may rigidly collide with the body of the axial loading rod 6, resulting in a sudden increase in additional bending moment, distortion of test data, or even structural damage. To avoid this problem, when the tilt displacement of the axial ball joint 51 reaches a preset safety threshold, the outer edge of the axial ball joint 51 will contact the elastic limiting pad 62.

[0056] At this point, the elastic limiting pad 62 provides cushioning through its own compression deformation, absorbing impact energy on the one hand and generating a reverse restoring force on the other, effectively limiting further deflection of the axial ball socket 51. While allowing normal slight free tilting to release working bending moment, it implements flexible limiting for abnormal large-angle deflection, protecting the precision spherical mating pair and ensuring that the loading process is always in a controllable and stable state, thereby ensuring the accuracy of axial stiffness testing and the safety of equipment operation.

[0057] See Figure 4 , Figure 5 , Figure 8 and Figure 9 As shown, a number of disc springs 63 are arranged coaxially with the axial loading rod 6 between the limiting sleeve 61 and the axial ball socket 51 to provide axial elastic preload.

[0058] In the initial stage of the test, several sets of disc springs 63, coaxially arranged with the axial loading rod 6, are pre-installed between the limiting sleeve 61 and the axial ball socket 51, forming an elastic support system surrounding the central load path. A stable axial elastic preload is applied to the axial ball socket 51. At the same time, when the loading flange 4 tilts slightly, the disc springs 63 can undergo asymmetric compression with changes in local force, providing a certain degree of flexible compliance, maintaining centering stability without hindering necessary free rotation.

[0059] See Figure 8 and Figure 9 As shown, the limiting sleeve 61 can move axially along the axial loading rod 6. The sliding frame 121 is provided with a sliding seat 122 for fixing the axial loading rod 6. The sliding seat 122 is provided with a gap adjustment component that is induced to be connected to the limiting sleeve 61, which is used to adjust the limiting gap between the elastic limiting pad 62 and the axial ball socket 51.

[0060] When replacing different models of wheel hub bearings and adjusting the test load amplitude, the limit clearance needs to be adjusted.

[0061] The hub bearing 2 with higher stiffness has less deformation under the same load, and a smaller limiting clearance can be used to improve response sensitivity.

[0062] If the bearing has low stiffness or large deformation under heavy load conditions, the limiting clearance needs to be increased to prevent the elastic limiting pad 62 from contacting too early and constraining its normal tilt, which would lead to additional bending moment and test distortion.

[0063] See Figure 8 and Figure 9 As shown, the spacing adjustment assembly includes a sliding sleeve 611 sleeved on the axial loading rod 6 and fixed to the upper end of the limiting sleeve 61. The sliding seat 122 is provided with an air chamber 1221. The upper end of the sliding sleeve 611 is slidably inserted into the air chamber 1221 and is provided with a piston 612. The side of the sliding seat 122 is provided with an air port 1222 communicating with the air chamber 1221.

[0064] When adjusting the limiting gap, compressed air is introduced into the air chamber 1221 through the air port 1222 on the side of the slide block 122, pushing the piston 612 at the upper end of the slide sleeve 611 to move smoothly along the axial direction within the air chamber 1221. Since the slide sleeve 611 is sleeved on the axial loading rod 6 and fixedly connected to the upper end of the limiting sleeve 61, the movement of the piston 612 directly drives the limiting sleeve 61 to move down synchronously along the axial loading rod 6, thereby precisely changing the distance between its lower end elastic limiting pad 62 and the axial ball socket 51.

[0065] When it is necessary to increase the limiting clearance, the gas in the air chamber 1221 can be discharged, allowing the sliding sleeve 611 to move upward under the action of the disc spring 63. Conversely, increasing the air pressure will push the sliding sleeve 611 downward, reducing the clearance. After setting a suitable limiting clearance according to the stiffness of the hub bearing 2 and the load conditions before the test, the air chamber 1221 can maintain pressure to lock the position of the sliding sleeve 611, ensuring the stability and reliability of the limiting structure during loading. This avoids test distortion caused by premature constraint and provides timely flexible limiting protection in case of abnormal large deformation, improving the adaptability of the tooling and the accuracy of the test.

[0066] See Figure 8 and Figure 9 As shown, multiple displacement sensors 123 are evenly distributed on the slide block 122 along the circumferential direction of the axial loading rod 6. The limiting sleeve 61 is provided with sensing points 124 corresponding to each displacement sensor 123, which are used to monitor the limiting gap and the deflection state between the elastic limiting pad 62 and the axial ball socket 51 in real time.

[0067] During the test, multiple displacement sensors 123, evenly distributed along the circumference of the axial loading rod 6 on the slide block 122, work in conjunction with the corresponding sensing points 124 on the limiting sleeve 61 to collect the axial position information of the limiting sleeve 61 relative to the slide block 122 in real time. Because the displacement sensors 123 are circumferentially symmetrically distributed, they can not only accurately measure the axial clearance between the elastic limiting pad 62 and the axial ball socket 51, but also determine whether the limiting sleeve 61 has tilted by comparing the differences in the readings of each displacement sensor 123.

[0068] On the one hand, it can verify whether the current limit clearance is within the preset safety range, avoiding over-constraint or protection failure. On the other hand, it can help identify abnormal loads or assembly deviations, improving the reliability of test data.

[0069] This invention achieves smooth axial load transfer and releases additional bending moment caused by flange tilt by rigidly fixing the actual vehicle steering knuckle 3 to the tooling table 1 and using a loading flange 4 rigidly connected to the wheel hub bearing 2 coaxially through the original vehicle bolt holes, combined with a surface contact universal joint 5 composed of an axial ball joint 52 and an axial ball socket 51. The vertical slide rail 12 drives the sliding frame 121 and the transverse slide rail 13 to rise and fall synchronously, ensuring that the radial loading rod 7 remains in contact with the side of the flange during axial loading and can apply radial load independently.

[0070] An adaptive structure 71, consisting of a radial ball socket 711, a radial ball head 712, and a rubber sleeve 713, is installed on the side of the loading flange 4. This, combined with the upper and lower coaxial stacked discs and the rigid installation method using double fixed plates, allows for slight rotation while preventing loosening and deformation, ensuring that only the true radial force is transmitted. Simultaneously, an adjustable limiting sleeve 61 with an elastic limiting pad 62 and a coaxial disc spring 63 are installed on the axial loading rod 6. The limiting gap is preset through a pneumatic gap adjustment component, accommodating both free tilting under normal operating conditions and flexible limiting during abnormal large deformations. This allows for high-precision and high-safety testing of axial and radial stiffness while retaining the conditions for actual vehicle testing.

[0071] The above embodiments only illustrate one or more implementations of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of protection of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A wheel hub bearing stiffness testing fixture based on a real vehicle steering knuckle, comprising a fixture table on which a fixture assembly is provided for mounting and rigidly fixing a real vehicle steering knuckle with a wheel hub bearing to be tested. characterized in that Also includes: A loading flange is rigidly connected to the end face of the wheel hub bearing to be tested through the original wheel bolt holes, and the loading flange is coaxial with the wheel hub bearing; A universal joint is located at the center of the loading flange; An axial loading rod is provided along the axial direction of the loading flange, and one end of the axial loading rod is connected to the universal joint for applying axial load; A radial loading rod is provided radially along the loading flange, with one end of the radial loading rod contacting and engaging with the side of the loading flange to apply a radial load; The system includes a vertical slide rail and a horizontal slide rail. The vertical slide rail is fixed to the tooling table, and a sliding frame for mounting the axial loading rod is slidably mounted on the vertical slide rail. The horizontal slide rail is fixed to the sliding frame, and the radial loading rod is slidably mounted on the horizontal slide rail.

2. The test fixture of claim 1, wherein, The universal joint includes an axial ball socket and an axial ball head. The axial ball socket is fixedly disposed at the center of the loading flange. The axial ball head is fixedly connected to the end of the axial loading rod. The axial ball head is embedded in the axial ball socket, and a surface contact fit is formed between the axial ball socket and the axial ball head.

3. The wheel hub bearing stiffness testing fixture based on a real vehicle steering knuckle according to claim 2, characterized in that, The loading flange is provided with an adaptive structure on the side corresponding to the radial loading rod, which is used to release the additional bending moment caused by the loading flange tilting around the axial ball head center.

4. The wheel hub bearing stiffness testing fixture based on a real vehicle steering knuckle according to claim 3, characterized in that, The adaptive structure is a radial ball socket fixedly installed on the side of the loading flange, and the end of the radial loading rod is provided with a radial ball head that mates with the radial ball socket.

5. The wheel hub bearing stiffness testing fixture based on a real vehicle steering knuckle according to claim 4, characterized in that, The radial ball head is fitted with a rubber sleeve embedded in the radial ball socket, which is used to elastically adapt to and release additional bending moment when the loading flange tilts around the axial ball head center.

6. The wheel hub bearing stiffness testing fixture based on a real vehicle steering knuckle according to claim 2, characterized in that, A limiting sleeve is fitted on the axial loading rod, and an elastic limiting pad is provided at the lower end of the limiting sleeve to provide buffering and limit the deflection angle when the axial ball socket is tilted.

7. The wheel hub bearing stiffness testing fixture based on a real vehicle steering knuckle according to claim 6, characterized in that, Several sets of disc springs, coaxially arranged with the axial loading rod, are provided between the limiting sleeve and the axial ball socket to provide axial elastic preload.

8. The wheel hub bearing stiffness testing fixture based on a real vehicle steering knuckle according to claim 7, characterized in that, The limiting sleeve can move axially along the axial loading rod. The sliding frame is provided with a slide block for fixing the axial loading rod. The slide block is provided with a gap adjustment component that is throttle-connected to the limiting sleeve, which is used to adjust the limiting gap between the elastic limiting pad and the axial ball socket.

9. The wheel hub bearing stiffness testing fixture based on a real vehicle steering knuckle according to claim 8, characterized in that, The spacing adjustment assembly includes a sliding sleeve sleeved on the axial loading rod and fixed to the upper end of the limiting sleeve. The sliding seat has an air chamber inside, the upper end of the sliding sleeve is slidably inserted into the air chamber and is provided with a piston, and the side of the sliding seat has an air port communicating with the air chamber.

10. The wheel hub bearing stiffness testing fixture based on a real vehicle steering knuckle according to claim 9, characterized in that, Multiple displacement sensors are evenly distributed on the slide block along the circumference of the axial loading rod. The limiting sleeve is provided with a sensing point corresponding to each displacement sensor, which is used to monitor the limiting gap and the deflection state between the elastic limiting pad and the axial ball socket in real time.

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