A single-machine load testing method and testing device for a wheel hub bearing durability testing machine

Abstract

The present invention relates to the technical field of wheel hub bearings, and more specifically, to a single-machine load testing method and testing device for a wheel hub bearing durability testing machine. The single-machine load testing method for a wheel hub bearing durability testing machine includes: based on the assembly of the wheel hub bearing and the strain gauge, performing a bending moment calibration test and a durability testing machine loading test on the wheel hub bearing; based on the completion of the bending moment calibration test, obtaining a calibration mapping relationship between a first bending moment value and a first strain value; based on the completion of the durability testing machine loading test, obtaining a second bending moment value and a second strain value; based on the calibration mapping relationship and the second bending moment value, calculating the theoretical strain value corresponding to the second bending moment value in the calibration mapping relationship; based on the deviation of the second strain value from the theoretical strain value within a preset range, the durability testing machine loading test is qualified, otherwise it is unqualified. The testing device is applied to the single-machine load testing method for the wheel hub bearing durability testing machine, thereby solving the problem of high cost of the wheel hub bearing durability testing machine testing method.

Description

Technical Field

[0001] The present invention relates to the technical field of wheel hub bearings, and in particular to a single-machine load testing method and testing device for a wheel hub bearing durability testing machine. Background Art

[0002] Durability testing of wheel hub bearings typically requires simulating the actual stress conditions of the wheel hub bearings using a durability tester. However, due to the instability of the loading force and test results after long-term use, the durability tester needs to be calibrated regularly. Existing technology uses multiple strain gauges attached to the outer ring of the bearing to measure the strain. A calibrated "standard durability tester" is used as a calibration reference for the "durability tester to be tested." Calibration is performed based on the strain difference between the two durability testers within the same loading force range.

[0003] However, this testing method has two problems: First, multiple strain gauges need to be attached to the outer ring of the bearing to measure the force. However, due to the uneven surface and irregular shape of the outer ring, the strain gauges are difficult to attach firmly, and the force is uneven. Multiple strain gauges must be attached to barely measure accurately, which is cumbersome and costly. Second, existing durability testing machines often use a non-rotating part loading method. According to the relationship between the action force and the reaction force, the loading direction is opposite to the force direction of the wheel in actual working conditions. Third, when calibrating the loading force, it is necessary to rely on a calibrated "standard durability testing machine" as a reference to compare the results. This method requires additional equipment and cannot directly test a single durability testing machine independently, making it very inconvenient to use. Therefore, there is an urgent need for a highly practical and convenient method to directly test a single durability testing machine. Summary of the Invention

[0004] In order to solve the problem that the testing method of a wheel hub bearing durability testing machine is not convenient enough, the present invention provides a single-machine load testing method and testing device for a wheel hub bearing durability testing machine.

[0005] In a first aspect, the present invention provides a single-machine load testing method for a wheel hub bearing durability testing machine. The single-machine load testing method for a wheel hub bearing durability testing machine comprises:

[0006] Step S10: After the hub bearing and the strain gauge are assembled, the hub bearing is subjected to a bending moment calibration test and a durability testing machine loading test;

[0007] Step S20: obtaining a calibration mapping relationship between a first bending moment value and a first strain value based on completion of the bending moment calibration test;

[0008] Step S30, based on the completion of the loading test of the durability testing machine, obtaining a second bending moment value and a second strain value;

[0009] Step S40, calculating a theoretical strain value corresponding to the second bending moment value in the calibration mapping relationship based on the calibration mapping relationship and the second bending moment value;

[0010] Step S50: Based on the deviation of the second strain value from the theoretical strain value being within a preset range, the endurance testing machine loading test is qualified;

[0011] Step S60 : Based on the second strain value deviating from the theoretical strain value and being outside the preset range, the endurance testing machine loading test fails.

[0012] In some embodiments, the wheel hub bearing comprises an inner ring, an outer ring, a flange, and rolling elements; the inner ring is rotatably connected to the outer ring; the inner ring is located inside the outer ring; the rolling elements are located between the inner ring and the outer ring; the flange is integrally formed with one end of the inner ring; and the flange is located outside the outer ring.

[0013] The bending moment calibration test includes applying unidirectional loading forces of different values to the flange in sequence; the endurance testing machine loading test includes applying loading forces of different values in the first direction and loading forces of different values in the second direction in sequence to the outer ring.

[0014] In some embodiments, the hub bearing further comprises a spline shaft and a nut; the spline shaft is meshed with the inner ring for transmission; an end of the spline shaft close to the flange is threadedly connected to the nut;

[0015] When the hub bearing and the strain gauge are assembled, the strain gauge is built into the spline shaft.

[0016] In some embodiments, when performing the bending moment calibration test, the flange is located above the outer ring, and the strain gauge is located below the nut;

[0017] A mounting hole is formed at one end of the spline shaft close to the flange; the strain gauge is located in the mounting hole; the mounting hole is filled with resin; and the resin wraps the strain gauge.

[0018] In some embodiments, the mounting hole includes a first countersunk hole and a second countersunk hole; the first countersunk hole is connected to the outside of the spline shaft; the second countersunk hole is connected to the first countersunk hole; the diameter of the first countersunk hole is larger than the diameter of the second countersunk hole; the strain gauge is located in the second countersunk hole.

[0019] In some embodiments, the ratio of the diameter of the second counterbore to the diameter of the first counterbore is a first ratio; the ratio of the diameter of the strain gauge to the diameter of the second counterbore is a second ratio; and the first ratio is greater than the second ratio.

[0020] In some embodiments, the first ratio is 0.6-0.7; the second ratio is 0.5-0.6.

[0021] In some embodiments, the ratio of the depth of the second countersunk hole to the depth of the first countersunk hole is a third ratio; the ratio of the length of the strain gauge along the axial direction of the spline shaft to the depth of the second countersunk hole is a fourth ratio; and the third ratio is greater than the fourth ratio.

[0022] In some embodiments, the third ratio is 0.8-0.9; the fourth ratio is 0.2-0.25.

[0023] In a second aspect, the present invention provides a single-unit load testing device for a wheel hub bearing durability testing machine, wherein the single-unit load testing device for a wheel hub bearing durability testing machine is applied to the single-unit load testing method for a wheel hub bearing durability testing machine in the first aspect, and the single-unit load testing device for a wheel hub bearing durability testing machine comprises:

[0024] wheel hub bearings;

[0025] a strain gauge, the wheel hub bearing being fixedly connected to the strain gauge;

[0026] A press, the press being used to perform a bending moment calibration test on the wheel hub bearing;

[0027] A durability testing machine is used to perform a loading test on the wheel hub bearing.

[0028] In order to solve the problem of high cost of the wheel hub bearing durability testing machine testing method, the present invention has the following advantages:

[0029] Without the need for a standard endurance tester, load calibration testing can be performed on a single endurance tester to assess the stability and accuracy of its loading force. It can also be used to benchmark the loading forces of multiple endurance testers. By directly measuring the actual bending moment experienced by the product, bearing forces are quantified, enabling a more accurate assessment of the test bench's impact on the product's dynamic life testing. Requiring only a single, low-cost press for moment calibration testing reduces testing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic flow chart showing a single-machine load testing method for a wheel hub bearing durability testing machine according to an embodiment is shown;

[0031] Figure 2 A schematic structural diagram of a device for calibrating the bending moment of a hub bearing according to an embodiment is shown;

[0032] Figure 3A schematic diagram of the structure of a device for testing the load of a wheel hub bearing durability testing machine according to one embodiment is shown;

[0033] Figure 4 A schematic diagram of the spline shaft structure of an embodiment is shown.

[0034] Reference numerals: 10 wheel hub bearing; 11 inner ring; 12 outer ring; 13 flange; 14 rolling element; 15 spline shaft; 16 nut; 17 mounting hole; 171 first countersunk hole; 172 second countersunk hole; 20 strain gauge; 30 press; 40 endurance testing machine. DETAILED DESCRIPTION

[0035] The present disclosure will now be discussed with reference to several exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the present disclosure, rather than to imply any limitation on the scope of the present disclosure.

[0036] As used herein, the term "including" and its variations are to be interpreted as open-ended terms meaning "including, but not limited to." The term "based on" is to be interpreted as "based, at least in part, on." The terms "one embodiment" and "an embodiment" are to be interpreted as "at least one embodiment." The term "another embodiment" is to be interpreted as "at least one other embodiment." Terms such as "upper," "lower," "left," "right," "front," "back," "top," "bottom," "inner," "outer," "vertical," "horizontal," "transverse," and "longitudinal" indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are primarily intended to better describe the present application and its embodiments and are not intended to limit the devices, elements, or components indicated to having a specific orientation, or to being constructed and operated in a specific orientation. Furthermore, some of the above terms may be used to indicate other meanings besides orientation or positional relationships. For example, the term "on" may, in certain circumstances, be used to indicate a dependency or connection relationship. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances. Furthermore, the terms "installed," "disposed," "provided with," "connected," and "connected" are to be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection, an indirect connection through an intermediate medium, or an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances. In addition, the terms "first", "second", etc. are mainly used to distinguish different devices, elements, or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise specified, "plurality" means two or more.

[0037] When testing the reliability of the bearing durability tester 40, the commonly used test method has some defects. First, it is necessary to measure the strain of the bearing by pasting a strain gauge 20 on the outer ring 12 of the bearing. However, the surface of the outer ring 12 of the bearing is uneven, and the strain gauge 20 will be difficult to fit completely and cause uneven force. Therefore, multiple strain gauges 20 are often pasted for comparison and calculation, which is troublesome and costly to operate. Secondly, a calibrated "standard durability tester 40" is required as a reference for the "durability tester 40 to be tested" for calibration. The steps are complicated and costly. Finally, the premise for the stable rotation of the wheel hub is that the wheel hub bearing 10 can stably withstand the complex forces transmitted to the bearing through the tire. These complex forces pass through the tire and the wheel hub and finally act on the rotating part of the wheel hub bearing 10, that is, the flange 13. When the durability tester adopts non-rotating parts for loading, its loading direction is opposite to that in the actual working conditions. Therefore, in this embodiment, a single-machine load testing method for a bearing durability tester 40 is provided, such as Figure 1 As shown, the single-machine load testing method of the bearing durability testing machine 40 includes steps S10 to S60, and each step is described in detail as follows:

[0038] Step S10: After the hub bearing 10 and the strain gauge 20 are assembled, the hub bearing 10 is subjected to a bending moment calibration test and a loading test on the durability testing machine 40;

[0039] Step S20: Based on the completion of the bending moment calibration test, a calibration mapping relationship between the first bending moment value and the first strain value is obtained. There may be multiple first bending moment values and multiple first strain values, and the calibration mapping relationship between the two can be considered as an accurate curve of the strain variation when the hub bearing 10 is subjected to different bending moments. The calibration mapping relationship can be expressed by the formula M=FaR=f(ε), where M is the bending moment, Fa is the loading force, R is the lever arm, and ε is the strain value.

[0040] Step S30 : Based on the completion of the loading test of the durability testing machine 40 , a second bending moment value and a second strain value are obtained. There are also multiple second bending moment values and second strain values.

[0041] Step S40, based on the calibration mapping relationship and the second bending moment value, calculate the theoretical strain value corresponding to the second bending moment value in the calibration mapping relationship, that is, substitute the second bending moment value M2 into the formula M=FaR=f(ε), and the obtained ε value is the theoretical strain value corresponding to the second bending moment value.

[0042] In step S50 , the measured second strain value is compared with the obtained theoretical strain value. Based on the fact that the deviation of the second strain value from the theoretical strain value is within a preset range, the endurance testing machine 40 passes the loading test.

[0043] In step S60 , based on the second strain value deviating from the theoretical strain value and being outside the preset range, the endurance testing machine 40 fails the loading test.

[0044] A single endurance tester 40 can be directly used for bending moment calibration testing. The endurance tester 40 to be tested can then be used to test different loads. Based on the mapping relationship, the theoretical strain value of the hub bearing 10 when the endurance tester 40 to be tested applies a loading force to the hub bearing 10 can be calculated. The difference between the theoretical strain value and the second strain value can then be used to determine the stability and accuracy of the loading force of the endurance tester 40 to be tested. This method eliminates the need to use two endurance testers 40 for test comparison, saving testing costs and simplifying the testing process.

[0045] In this embodiment, if Figure 2 As shown, the hub bearing 10 includes an inner ring 11, an outer ring 12, a flange 13, and rolling elements 14. The inner ring 11 and the outer ring 12 are rotatably connected, with the inner ring 11 positioned inside the outer ring 12, and the rolling elements 14 positioned between the inner ring 11 and the outer ring 12. The flange 13 is integrally formed with one end of the inner ring 11 and positioned outside the outer ring 12.

[0046] The bending moment calibration test, consistent with the force transfer conditions experienced during actual vehicle operation, involves sequentially applying unidirectional loads of varying magnitudes to the flange 13. This unidirectional load acts as an axial force on the wheel hub bearing 10 in the opposite direction of the load. In the actual operating conditions of the wheel hub bearing 10, the inner ring 11 is detachably connected to the wheel hub via the flange 13. Therefore, applying the load directly to the flange 13 during the bending moment calibration test more closely resembles the actual operating conditions of the wheel hub bearing 10. This results in more reliable results than conventional testing methods that often apply the load to the outer ring 12 of the wheel hub bearing 10.

[0047] The endurance testing machine 40 load test involves sequentially applying a load force of varying magnitudes in a first direction and a load force of varying magnitudes in a second direction to the outer ring 12. The first direction can be parallel to the axis of the hub bearing 10, and the second direction can be perpendicular to the axis of the hub bearing 10. Both the first and second forces acting on the hub bearing 10 constitute a bending moment. Furthermore, during the endurance testing machine 40 load test, the inner ring 11 can be controlled to prevent rotation, thereby maintaining consistency with the bending moment calibration test.

[0048] In this embodiment, if Figure 4 As shown, when the hub bearing 10 and the strain gauge 20 are assembled, the strain gauge 20 is built into the spline shaft 15, so that when the durability testing machine 40 applies loading forces in different directions, the strain gauge 20 is located in the center of the hub bearing 10, and a more obvious strain amount can be sensed.

[0049] In this embodiment, if Figure 3As shown, the wheel hub bearing 10 further includes a spline shaft 15 and a nut 16. The spline shaft 15 is meshed with the inner ring 11 for transmission, and the end of the spline shaft 15 near the flange 13 is threadedly connected to the nut 16. By integrating the strain gauge 20 into the spline shaft 15, the strain gauge 20 can be located on the axis of the wheel hub bearing 10, thereby more clearly sensing the strain of the wheel hub bearing 10.

[0050] During the bending moment calibration test, the flange 13 is located above the outer ring 12 to facilitate application of pressure, and the strain gauge 20 is located below the nut 16 , making it easier to sense the strain of the hub bearing 10 without being disturbed by the strain of the nut 16 .

[0051] A mounting hole 17 is defined at one end of the spline shaft 15 near the flange 13. The strain gauge 20 is positioned within the mounting hole 17, making it easier to install and remove the strain gauge 20 and to route its signal lines. The mounting hole 17 can be filled with resin, which completely encapsulates the strain gauge 20, securing it in place while also better transmitting strain to the hub bearing 10.

[0052] In this embodiment, if Figure 4 As shown, mounting hole 17 includes a first countersunk hole 171 and a second countersunk hole 172. First countersunk hole 171 communicates with the exterior of spline shaft 15, while second countersunk hole 172 communicates with first countersunk hole 171. The diameter of first countersunk hole 171 is larger than that of second countersunk hole 172, making it easier to inject resin into mounting hole 17 through the larger diameter of first countersunk hole 171. Strain gauge 20, however, is located in second countersunk hole 172, which has a smaller diameter. Less resin is injected into the second countersunk hole 172, facilitating the sensing of strain in hub bearing 10.

[0053] In this embodiment, the ratio of the diameter of the second countersunk hole 172 to the diameter of the first countersunk hole 171 can be a first ratio, and the ratio of the diameter of the strain gauge 20 to the diameter of the second countersunk hole 172 can be a second ratio. The first ratio is greater than the second ratio, that is, the diameter of the strain gauge 20 is smaller than the diameter of the second countersunk hole 172, which is smaller than the diameter of the first countersunk hole 171. The diameter of the first countersunk hole 171 can be slightly larger than the diameter of the second countersunk hole 172 to facilitate resin injection, while the diameter of the second countersunk hole 172 can be significantly larger than the diameter of the strain gauge 20. This not only facilitates resin inflow, but also allows the resin to completely encapsulate the strain gauge 20, reducing gaps and making the strain of the hub bearing 10 measured by the strain gauge 20 more accurate.

[0054] In this embodiment, the first ratio can be 0.6~0.7; the second ratio can be 0.5~0.6, that is, the diameter of the strain gauge 20 is smaller than the diameter of the second countersunk hole 172 and smaller than the diameter of the first countersunk hole 171, so that the resin is easy to inject and can completely wrap the strain gauge 20.

[0055] In this embodiment, the ratio of the depth of the second counterbore 172 to the depth of the first counterbore 171 is a third ratio. The ratio of the axial length of the strain gauge 20 along the spline shaft 15 to the depth of the second counterbore 172 is a fourth ratio. The third ratio is greater than the fourth ratio, meaning that the depth of the first counterbore 171 is greater than the depth of the second counterbore 172, which is greater than the axial length of the strain gauge 20 along the spline shaft 15. This ensures that the resin encapsulates the strain gauge 20, reduces gaps, and more accurately measures the strain of the hub bearing 10 using the strain gauge 20.

[0056] In this embodiment, the third ratio is 0.8-0.9; the fourth ratio is 0.2-0.25, that is, the length of the strain gauge 20 is smaller than the length of the second countersunk hole 172 and smaller than the length of the first countersunk hole 171 , so that the resin can be easily injected and can completely wrap the strain gauge 20 .

[0057] In this embodiment, if Figure 3 As shown, the wheel hub bearing 10 endurance test machine 40 single-unit load testing device includes the wheel hub bearing 10, a strain gauge 20, a press 30, and the endurance test machine 40. The wheel hub bearing 10 and the strain gauge 20 are fixedly connected by resin, allowing the strain gauge 20 to accurately detect the strain of the wheel hub bearing 10. The press 30 can be used to perform bending moment calibration testing on the wheel hub bearing 10; the endurance test machine 40 to be tested is used to perform endurance test 40 loading testing on the wheel hub bearing 10. By comparing the results of the bending moment calibration test and the endurance test machine 40 loading test, the loading and testing accuracy of the endurance test machine 40 to be tested can be determined. At the same time, the endurance test machine 40 to be tested can be calibrated based on the difference in the results.

[0058] It should be understood that the “present embodiment” mentioned in the present invention is based on the technical points currently described, and multiple “present embodiments” may be the same embodiment or different embodiments.

[0059] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present disclosure, and that in actual applications, various changes may be made thereto in form and detail without departing from the scope of the present disclosure.

Claims

1. A single-machine load testing method for a wheel hub bearing durability testing machine, characterized in that: The wheel hub bearing durability testing machine single machine load testing method includes: Step S10: After the hub bearing and the strain gauge are assembled, the hub bearing is subjected to a bending moment calibration test and a durability testing machine loading test; Step S20: obtaining a calibration mapping relationship between a first bending moment value and a first strain value based on completion of the bending moment calibration test; Step S30, based on the completion of the loading test of the durability testing machine, obtaining a second bending moment value and a second strain value; Step S40, calculating a theoretical strain value corresponding to the second bending moment value in the calibration mapping relationship based on the calibration mapping relationship and the second bending moment value; Step S50: Based on the deviation of the second strain value from the theoretical strain value being within a preset range, the endurance testing machine loading test is qualified; Step S60: Based on the second strain value deviating from the theoretical strain value and being outside the preset range, the endurance testing machine loading test fails; The wheel hub bearing comprises an inner ring, an outer ring, a flange and rolling elements; the inner ring is rotatably connected to the outer ring; the inner ring is located inside the outer ring; the rolling elements are located between the inner ring and the outer ring; the flange is integrally formed with one end of the inner ring; and the flange is located outside the outer ring; The bending moment calibration test includes sequentially applying unidirectional loads of different values to the flange; the endurance test machine loading test includes sequentially applying loads of different values in a first direction and loads of different values in a second direction to the outer ring; The hub bearing further comprises a spline shaft and a nut; the spline shaft is meshed with the inner ring for transmission; one end of the spline shaft close to the flange is threadedly connected to the nut; When the hub bearing and the strain gauge are assembled, the strain gauge is built into the spline shaft.

2. A single-machine load testing method for a wheel hub bearing durability testing machine according to claim 1, characterized in that: When performing the bending moment calibration test, the flange is located above the outer ring, and the strain gauge is located below the nut; A mounting hole is formed at one end of the spline shaft close to the flange; the strain gauge is located in the mounting hole; the mounting hole is filled with resin; and the resin wraps the strain gauge.

3. The single-machine load testing method for a wheel hub bearing durability testing machine according to claim 2, characterized in that: The mounting hole includes a first countersunk hole and a second countersunk hole; the first countersunk hole is connected to the outside of the spline shaft; the second countersunk hole is connected to the first countersunk hole; the diameter of the first countersunk hole is larger than the diameter of the second countersunk hole; the strain gauge is located in the second countersunk hole.

4. A single-machine load testing method for a wheel hub bearing durability testing machine according to claim 3, characterized in that: The ratio of the diameter of the second countersunk hole to the diameter of the first countersunk hole is a first ratio; the ratio of the diameter of the strain gauge to the diameter of the second countersunk hole is a second ratio; and the first ratio is greater than the second ratio.

5. The single-machine load testing method for a wheel hub bearing durability testing machine according to claim 4, characterized in that: The first ratio is 0.6-0.7; the second ratio is 0.5-0.

6.

6. The single-machine load testing method for a wheel hub bearing durability testing machine according to claim 3, characterized in that: The ratio of the depth of the second countersunk hole to the depth of the first countersunk hole is a third ratio; the ratio of the length of the strain gauge along the axial direction of the spline shaft to the depth of the second countersunk hole is a fourth ratio; the third ratio is greater than the fourth ratio.

7. A single-machine load testing method for a wheel hub bearing durability testing machine according to claim 6, characterized in that: The third ratio is 0.8-0.9; the fourth ratio is 0.2-0.

25.

8. A single-unit load testing device for a wheel hub bearing durability testing machine, applied to the single-unit load testing method for a wheel hub bearing durability testing machine according to any one of claims 1 to 7; characterized in that: The wheel hub bearing durability testing machine single machine load testing device includes: A wheel hub bearing, comprising an inner ring, an outer ring, a flange, and rolling elements; the inner ring is rotatably connected to the outer ring; the inner ring is located inside the outer ring; the rolling elements are located between the inner ring and the outer ring; the flange is integrally formed with one end of the inner ring; and the flange is located outside the outer ring; a strain gauge, the wheel hub bearing being fixedly connected to the strain gauge; A press, the press is used to perform a bending moment calibration test on the hub bearing; the bending moment calibration test includes sequentially applying unidirectional loading forces of different values to the flange; A durability testing machine is used to perform a loading test on the hub bearing; the loading test includes sequentially applying loading forces of different values in a first direction and loading forces of different values in a second direction to the outer ring.

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