Device and method for testing rolling bearing with variable shaft diameter

Abstract

The invention discloses a variable-shaft-diameter rolling bearing testing device and testing method, and aims to solve the problems that an existing rolling bearing testing device is difficult to adapt to bearings with different shaft diameter specifications, and a main shaft needs to be replaced frequently. The device is composed of a testing platform, a lead screw driving mechanism, an axial loading mechanism, an inner diameter variable mechanism, an outer diameter variable mechanism, a main shaft, a bearing seat mechanism, a main shaft coupler, a main shaft motor and a supporting frame. The inner diameter variable mechanism adapts to the inner diameters of different rolling bearings through a plurality of ring petals and a chuck structure, the outer diameter variable mechanism can adjust the outer diameter and the radial applied force in real time according to the outer diameter of the rolling bearing, the axial loading mechanism can apply a preset axial load to the bearing, and besides conventional constant axial force, the axial loading mechanism can also apply axial torque in different directions. The device can adapt to the testing of rolling bearings with various shaft diameter specifications without replacing the whole set of main shaft, effectively shortens the testing preparation time, and improves the testing efficiency. And the universality and the applicability are high.

Description

Technical Field

[0001] This invention relates to the field of rolling bearing testing technology, and specifically to a rolling bearing testing device and method with variable shaft diameter. Background Technology

[0002] As a core component in mechanical equipment, rolling bearings directly determine the operational stability, service life, and working efficiency of the entire machine through their performance indicators such as rotational accuracy, load-bearing capacity, friction characteristics, and reliability. They are widely used in critical fields such as automobiles, wind power, machine tools, and rail transportation. Therefore, appropriate bearing testing equipment is needed to assess the performance of rolling bearings during the research, development, production, and quality inspection processes.

[0003] Existing rolling bearing testing equipment typically uses a fixed-diameter spindle as the core of the testing platform. Centering is achieved through an interference fit or transition fit between the spindle and the inner ring of the bearing under test. A pre-set load is then applied using a loading mechanism, and performance parameters are tested in conjunction with modules for speed control and temperature acquisition. This type of equipment can meet basic requirements for batch testing of bearings with a single shaft diameter (see CN220366999U for details). However, with the diversification of the equipment manufacturing industry, the same manufacturer often needs to perform performance testing on bearings with different shaft diameters. Fixed-diameter testing equipment has poor adaptability; for each bearing with a different shaft diameter, a spindle component of the corresponding size must be replaced. Furthermore, frequent disassembly and replacement of the spindle can compromise the stability of the original mounting reference.

[0004] Meanwhile, existing axial loading devices can usually only apply pure axial force to simulate the conventional working condition of rolling bearings bearing constant axial load, but lack simulation of unconventional off-center loading conditions. Rolling bearings are often accompanied by bending moment in actual working conditions. Many radial loading devices are large and bulky, and in order to adapt to bearings of different sizes, it is necessary to replace the entire bearing housing, loading arm or even the entire support mechanism. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide a rolling bearing testing device and testing method with variable shaft diameter. The device mainly has the following functions: 1. It can be used for performance testing of rolling bearings with different shaft diameters; 2. It can apply different axial loads to simulate a variety of actual working conditions; 3. It simplifies the original testing device.

[0006] To achieve the above functions, the present invention adopts the following technical solution: In a first aspect, the present invention proposes a rolling bearing testing device with variable shaft diameter, comprising a testing platform; A lead screw drive module and an axial loading module are set at one end of the test platform; an inner diameter variable module and an outer diameter variable module are set at the middle position; and a bearing housing module, a spindle, a spindle motor, and a support frame are set at the other end. The lead screw drive module is connected to the axial loading module and is used to drive the axial loading module to move along the axial direction of the rolling bearing; the axial loading module includes multiple independently controlled hydraulic push rods for applying axial force to the outer ring of the rolling bearing. The inner diameter variable module and the outer diameter variable module are coaxially arranged, and the inner diameter variable module is located in the inner ring of the outer diameter variable module; The main spindle motor is supported by a support frame and connected to the main spindle, which is supported by a bearing housing module; the main spindle is coaxially arranged with the inner diameter variable module and the outer diameter variable module.

[0007] As a further technical solution, the variable outer diameter module includes a loading shell, an electric push rod, a mounting frame, hinge plate one, hinge plate two, arc spring two, a hinge shaft, a temperature sensor, a force sensor, and a vibration sensor. The loading shell is fixed to the test platform by screws and contains four equidistant electric push rods. The push rod of each electric push rod is connected to the mounting frame, and hinge plate one and hinge plate two are set on each mounting frame. The hinge shaft passes through the through holes on hinge plate one, hinge plate two, and the mounting frame, so that hinge plate one and hinge plate two are fixed on the mounting frame. The inner side of hinge plate one and hinge plate two is connected to arc spring two. The temperature sensor, force sensor, and vibration sensor are placed on different hinge plates one and hinge plate two. Each hinge plate one and hinge plate two is tangent to the outer ring of the bearing under test, and is used to apply radial force to the bearing under test.

[0008] As a further technical solution, the variable inner diameter module includes a jaw, an arc-shaped spring, a ring, an upper chuck body, a lower chuck body, a pressure plate, and a fastening nut; the upper chuck body, lower chuck body, pressure plate, and fastening nut are arranged coaxially in sequence, and the main shaft passes through the upper chuck body, lower chuck body, and pressure plate in sequence, and is threadedly engaged with the fastening nut; the lower chuck body is connected to the drive tool. The upper chuck body has mounting grooves for the jaws to move radially along the upper chuck body, and multiple jaws are slidably connected in the corresponding mounting grooves. The mounting grooves provide precise guidance for the linear movement of the jaws, enabling the jaws to move accurately and stably radially along the mounting grooves. At the same time, the surface of the lower chuck body, which is in close contact with the upper chuck body, is provided with flat threads for connecting the limiting blocks at the bottom of the jaws. The radially protruding ends of the jaws cooperate with the concave and convex shapes on the inner side of the ring petals. The two end faces of each ring petal are connected by a pair of arc-shaped springs, and multiple ring petals can be spliced ​​together to form a complete circular ring.

[0009] As a further technical solution, the initial spacing of each limiting block of the multiple jaws is slightly different, determined by the planar thread of the lower chuck body, to ensure that the eight jaws can expand and contract radially synchronously.

[0010] As a further technical solution, the outer middle of multiple annular lobes is provided with shoulders of the same height, which can be used for axial fixation of the bearing to be tested later.

[0011] As a further technical solution, the axial loading module includes a hydraulic cylinder, telescopic columns, a 90° elbow, a force sensor, a pressure regulating valve, and a hydraulic push rod; the hydraulic cylinder is connected and fixed to the disc, and four telescopic columns are equidistantly fixed on the four sides of the disc circumference, each telescopic column being connected to a pressure regulating valve through a 90° elbow; a hydraulic push rod is installed at the outlet of each pressure regulating valve, and a force sensor is installed on the hydraulic push rod.

[0012] As a further technical solution, the lead screw drive module includes a lead screw motor, a support base, a lead screw coupling, a lead screw, guide columns, a limit block, and a support slider; the lead screw motor is connected to the support base and connected to the lead screw through the lead screw coupling; two guide columns are set on both sides of the lead screw; the support slider is slidably connected to the lead screw and guide columns; it can move axially by being driven by the lead screw motor; a limit block is provided at the top, which can be used to fix the axial loading module.

[0013] As a further technical solution, one side of the spindle is connected to the spindle motor via a spindle coupling, and the other side of the spindle passes through a bearing support frame and an inner diameter variable module. The tail of the spindle is threaded for connection with a fastening nut. At the same time, different parts of the spindle are provided with shoulders and flat keys. The flat key is embedded in the keyway of the upper chuck body, and the shoulders are used for axial fixation of the deep groove ball bearing and the chuck body, respectively.

[0014] Secondly, based on the above-mentioned variable shaft diameter rolling bearing testing device, the present invention also proposes a testing method, as follows; 1. Start the lead screw drive module to move the axial loading module to a suitable distance, leaving reasonable space for the installation of the roller bearing and the loading of the drive tool; 2. Install the roller bearing into the ring of the variable inner diameter module, with one side of the bearing against the shoulder of the ring. Loosen the fastening nut, use the drive tool to rotate the lower chuck body, causing the ring to expand until it fits against the inner ring of the bearing. Then remove the drive tool, tighten the fastening nut, and apply lubricating oil to the bearing using the oil supply nozzle. 3. Use control elements to drive the variable outer diameter module to clamp the outer ring of the bearing; 4. Adjust the axial loading module so that it contacts the outer ring of the roller bearing, and apply the set axial force to the outer ring of the bearing through the lead screw drive module; 5. Start the spindle motor and set a reasonable speed. When the measured roller bearing reaches the set speed or the values ​​of the temperature sensor and vibration sensor on the hinge exceed the set threshold, turn off the spindle motor, remove the measured bearing, observe its fatigue characteristics, and complete the test.

[0015] As a further technical solution, the device can be restored to its initial state, and different test bearings can be installed to perform bearing performance tests.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention utilizes the interplay of an inner and outer diameter variable mechanism to adapt to the testing of various specifications of rolling bearings, eliminating the need to replace the entire spindle and fulfilling bearing testing requirements. It solves the problems of frequent spindle disassembly and replacement and cumbersome calibration procedures required by existing fixed-diameter devices, while also reducing equipment wear and testing accuracy issues caused by frequent disassembly and assembly.

[0017] The axial loading mechanism of this invention can independently control the load output at four loading points. Compared to existing devices that can only apply a constant uniform load, this device can simulate uniform axial loads and reproduce the bearing's operating conditions under eccentric loading, expanding the testing capabilities for special operating conditions and providing technical support for the research and development and performance optimization of bearings for special operating conditions. This invention has high versatility and adaptability. The radial loading device is relatively simple and can adapt to bearings of different sizes. In other words, this invention enables a single testing device to cover multiple shaft diameter specifications and simulate various bearing application conditions, reducing testing costs. Simultaneously, the simplified integrated design makes the entire testing process smooth and improves testing efficiency. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of a rolling bearing testing device with a variable shaft diameter; Figure 2 This is a schematic diagram of the lead screw drive module; Figure 3 These are a schematic diagram and a partially enlarged view of the axial loading module. Figure 4 This is a schematic diagram of the center section of the pressure regulating valve; Figure 5 This is a schematic diagram of the axial force acting on the outer ring of the bearing under test; Figure 6 This is a schematic diagram of the structure of the variable inner diameter module; Figure 7 This is an exploded view of the internal parts of the variable diameter module; Figure 8 This is an exploded view of the chuck structure; Figure 9 This is a schematic diagram of the structure of the variable outer diameter module; Figure 10 This is a side view of the module with variable inner and outer diameters; Figure 11 This is a structural schematic diagram of the bearing housing module; Figure 12 This is a schematic diagram of the main shaft.

[0019] In the diagram: 1. Test platform; 2. Lead screw drive module; 21. Lead screw motor; 22. Support seat; 23. Lead screw coupling; 24. Guide column; 25. Lead screw; 26. Limit block; 27. Support slider; 3. Axial loading module; 31. Hydraulic cylinder; 32. Telescopic column; 33. 90° elbow; 34. Force sensor; 35. Pressure regulating valve; 351. Adjusting handle; 352. Spring washer; 353. Pressure regulating spring; 354. Spring seat; 355. Diaphragm; 356. Damping orifice; 357. Valve core; 358. Return spring; 359. Valve seat; 3510. Valve body; 3511. Valve cover; 4. Variable inner diameter module; 41. Claw; 411. Claw thread; 412. Claw key; 42. Curved spring 1. 43. Ring Lobe; 44. Upper Chuck Body; 441. Groove; 442. Mounting Slot; 443. Central Through Hole; 45. Lower Chuck Body; 451. Boss; 452. Small Round Hole; 453. Flat Thread; 46. Pressure Plate; 47. Fastening Nut; 5. Variable Outer Diameter Module; 51. Loading Shell; 52. Electric Push Rod; 53. Mounting Bracket; 54. Hinge Plate 1; 55. Hinge Plate 2; 56. Arc Spring 2; 57. Hinge Shaft; 58. Temperature Sensor; 59. Vibration Sensor; 6. Main Spindle; 61. Shoulder; 62. Flat Key; 63. External Thread; 7. Bearing Seat Module; 71. Bearing Support Frame; 72. Deep Groove Ball Bearing; 73. Elastic Retaining Ring; 8. Main Spindle Coupling; 9. Main Spindle Motor; 10. Support Frame. Detailed Implementation

[0020] For ease of description, the words "up," "down," "left," and "right" appearing in this invention only indicate that they are consistent with the up, down, left, and right directions of the accompanying drawings themselves, and do not limit the structure. They are merely for the purpose of facilitating the description of this invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0021] As described in the background section, in view of the shortcomings of existing rolling bearing testing devices, the purpose of this invention is to provide a testing device that can change the inner and outer rings of the bearing according to the bearing shaft diameter, and can independently control the axial load applied to the bearing by four hydraulic push rods according to the axial loading device. It can simulate conventional axial load conditions, and can also apply axial torque to simulate off-center load conditions. It can test the bearing off-center load conditions of wind turbine generators, large gearboxes, improper installation, etc., thereby verifying the reliability of the bearing design.

[0022] Definition of terms: In this invention, "axial direction" is defined based on the axial direction of the rolling bearing.

[0023] The following is in conjunction with the appendix Figure 1 —Appendix Figure 12 The present invention will be described in detail below. The specific structure is as follows: The present invention discloses a rolling bearing testing device with variable shaft diameter, which specifically includes a testing platform 1, a lead screw drive module 2, an axial loading module 3, an inner diameter variable module 4, an outer diameter variable module 5, a main shaft 6, a bearing housing module 7, a main shaft coupling 8, a main shaft motor 9, and a support frame 10.

[0024] The above structure will be explained in detail below with reference to the accompanying drawings: like Figure 1 As shown, in this embodiment, the lead screw drive module 2, the variable outer diameter module 5, the bearing seat module 7, and the support frame 10 are fixed on the test platform 1 by screw connection.

[0025] like Figure 2 and Figure 3 As shown, the lead screw drive module 2 in this embodiment includes a lead screw motor 21, a support base 22, a lead screw coupling 23, guide posts 24, a lead screw 25, a limit block 26, and a support slider 27. The two support bases 22 are placed flush and fixed to the test platform 1 with screws, and have three through holes. The central through hole is used to place the lead screw 25, and two guide posts 24 are installed in the holes symmetrically distributed on both sides of the central through hole. The left support base 22 is connected to the lead screw motor 21, passes through the central through hole, and is connected to the lead screw coupling 23. The other side of the lead screw coupling 23 is connected to the lead screw 25. The right support base 22 is slightly lower than the left support base 22 to prevent the lower pressure regulating valve 35 and hydraulic push rod 36 of the axial loading module 3 from touching the right support base. The support slider 27 is mounted on the lead screw 25 and two guide posts 24. The support slider 27 is threaded into the lead screw 25 and engages with the through holes of the two guide posts 24. Two limit blocks 26 are fixed to the upper part of the support slider 27 to hold the two end caps of the hydraulic cylinder 31, thereby connecting the axial loading module 3. During operation, by starting the lead screw motor 21, the lead screw motor 21 drives the support slider 27 on the lead screw 25 to move axially to the desired position, thereby moving the axial loading module 3 to the desired position.

[0026] like Figure 3As shown, the axial loading module 3 in this embodiment includes a hydraulic cylinder 31, a telescopic column 32, a 90° elbow 33, a force sensor 34, a pressure regulating valve 35, a hydraulic push rod 36, and pins 37. The two end caps on the hydraulic cylinder 31 are fixed to the support slider 27 by two limiting blocks 26, allowing axial movement. Four circular holes (in the four directions of up, down, left, and right) are evenly distributed on the side of the right-hand disc of the hydraulic cylinder 31. The four telescopic columns 32 are tightly connected to the disc by threads. The outer telescopic column of the telescopic column 32 is fixed to the disc, while the inner telescopic column can extend and retract by internal hydraulic pressure. Simultaneously, three rows of densely packed small circular holes are opened on the inner and outer columns of the telescopic column 32. The inner and outer circular holes have the same diameter, ensuring that the inner and outer circular holes are coaxial when the telescopic column 32 extends or shortens. Three pins 37 are installed in the outer column's circular hole, which can be inserted into the inner column's circular hole to lock the inner column, controlling the extension and retraction length of the telescopic column 32 and maintaining it at the required test length. The inner side of the telescopic column 32 has a threaded top, connecting to a 90° elbow 33. The other side of the 90° elbow 33 connects to the oil inlet of a pressure regulating valve 35, and the oil outlet of the pressure regulating valve 35 connects to hydraulic push rods 36 (all four hydraulic push rods 36 are horizontally aligned), all secured by threaded connections. The hydraulic push rods 36 can extend and retract within a certain range using internal oil pressure, and a force sensor 34 is connected to them, displaying the axial thrust value of this hydraulic push rod on a computer.

[0027] Furthermore, the hydraulic cylinder 31, telescopic column 32, 90° elbow 33, pressure regulating valve 35, and hydraulic push rod 36 are equipped with oil circuits. The hydraulic oil flows in the internal hydraulic chamber of the axial loading module 3 and finally acts on the four hydraulic push rods 36 to drive the hydraulic push rods 36 to apply axial load to the bearing under test.

[0028] like Figure 4As shown, the pressure regulating valve 35 in this embodiment includes an adjusting handle 351, a spring washer 352, a pressure regulating spring 353, a spring seat 354, a diaphragm 355, a damping orifice 356, a valve core 357, a return spring 358, a valve seat 359, a valve body 3510, and a valve cover 3511. The spring washer 352 is connected above the pressure regulating spring 353, and it rests on the spring seat 354 below. The adjusting handle 351 is fixed to the upper end of the spring washer 352. By rotating the adjusting handle 351, the required preload is applied to the spring 353, thereby determining the outlet pressure of the pressure regulating valve. The diaphragm 355 and the valve core 357 are connected below the spring seat 354. The valve seat 359 is connected below the valve core 357, and the return spring 358 is placed below the valve seat. The valve body 3510 and valve cover 3511 are fixedly connected by bolts. Different O-rings are placed in the internal groove of the valve body 3510 for sealing. The remaining parts of the pressure regulating valve are respectively placed inside the valve body 3510 and valve cover 3511. During operation, hydraulic oil flows in from the inlet and through the internal oil passage to the outlet. At the same time, the hydraulic oil pushes the diaphragm 355 through the damping hole 356 at the outlet. When the pressure exceeds the preload of the pressure regulating spring 353, it pushes the diaphragm 355 to move the valve core 357 upward, which in turn moves the valve seat 359 upward, reducing the flow area at the outlet and maintaining the pressure at the outlet at a fixed value. The return spring 358 is used to close the valve when there is no pressure in the oil passage. By adjusting the handle 351 to apply the required preload to the pressure regulating spring 353, the oil pressure at the outlet of the pressure regulating valve can be controlled to the required pressure value.

[0029] Furthermore, the axial loading module 3 can apply different oil pressures to the four axial hydraulic push rods 36 through internal oil pressure transformation, driving the hydraulic push rods 36 to apply the required axial load to the bearing under test. During operation, the internal oil pressure of the hydraulic cylinder 31 increases, and the telescopic column 32 reaches the length of the outer ring of the rolling bearing under test. The length of the telescopic column 32 is mechanically locked by the pin 37. The oil outlet pressure of the pressure regulating valve 35 is adjusted by adjusting the handle 351 to set the oil pressure of the four branches to the required value. The hydraulic push rods 36 can extend and press against the outer ring of the bearing under test by relying on oil pressure. The axial force of the four hydraulic push rods is obtained by the force sensor 34 on them. According to the test requirements, the axial force of the four hydraulic push rods 36 can be set to the same value to simulate the working performance of the bearing under normal working conditions, or the axial force of the four hydraulic push rods 36 can be set to different values ​​to simulate the working performance of the bearing under off-center loading conditions.

[0030] like Figure 5As shown in the diagram, this schematic illustrates one form of axial force on the outer ring of the bearing under test. Traditional devices typically apply a constant axial force to the bearing under normal operating conditions, meaning F1-F4 are of uniform magnitude. The axial loading module 3 of this device can set F1-F4 to different values. Setting F1-F4 to be the same simulates normal operating conditions. In the diagram, F2-F4 are set to the same value, while the F1 value is increased, creating an axial bending moment to simulate an off-center load condition. Depending on the testing requirements, setting F1-F4 to the desired values ​​simulates the axial force experienced by the bearing under different operating conditions.

[0031] like Figures 6-8 As shown, the variable inner diameter module 4 in this embodiment includes a chuck 41, an arc spring 42, a ring 43, an upper chuck body 44, a lower chuck body 45, a pressure plate 46, and a fastening nut 47. The bottom of the upper chuck body 44 has a groove 441 that engages with the boss 451 on the top of the lower chuck body 45, ensuring the two chucks are coaxial. The bottom of the lower chuck body 45 has three small round holes 452 for easy access of the drive tool. A pressure plate 46 is mounted on the bottom, and the other side of the pressure plate 46 is connected to the fastening nut 47. The fastening nut 47 engages with the thread of the spindle 6, locking the axial displacement of the variable inner diameter module 4, allowing the module to rotate synchronously with the spindle 6. The spindle 6 passes through the through holes of the upper chuck body 44, lower chuck body 45, pressure plate 46, and fastening nut 47, ensuring that the central axes of each component are located on the spindle axis.

[0032] Furthermore, the upper chuck body 44 has mounting grooves 442 for the jaws 41 to move radially along the upper chuck body 44, and the eight jaws 41 are slidably connected in the corresponding eight mounting grooves 442. The mounting grooves 442 provide precise guidance for the linear movement of the jaws 41, enabling the jaws 41 to move accurately and stably along the radial direction of the mounting grooves. At the same time, a keyway is formed in the central through hole 443 of the upper chuck body 44 for connection with the flat key on the spindle 6. When the spindle 6 rotates, the upper chuck body 44 will also rotate, and the axial position of the upper chuck body 44 is fixed by the shoulder of the spindle 6. The surface of the lower chuck body 45, which is in close contact with the upper chuck body 44, is provided with a planar thread 453. The thread of the planar thread 453 is spiraled from the inner ring to the outer ring, and is connected to the jaw thread 411 at the bottom of the jaw 41 through spiral engagement. The jaw thread 411 is threadedly engaged with the planar thread 453. The initial spacing of the threads 411 of the eight jaws 41 is slightly different, determined by the planar thread 453 of the lower chuck body 45, to ensure that the eight jaws 41 extend and retract radially synchronously. The radially extending ends of the jaws 41 have jaw keys 412, which can mate with the grooves on the inner side of the ring lobes 43. The outer middle of the eight ring lobes 43 has shoulders of the same height, which can be used for axial fixation of the bearing to be tested later. The two end faces of each ring lobe 43 are connected by a pair of arc-shaped springs 42, and the eight ring lobes can be spliced ​​into a complete circular ring.

[0033] Furthermore, when the variable inner diameter module 4 is in operation, by loosening the fastening nut 47, with the lower chuck body 45 tightly against the surface of the pressure plate 46, the driving tool (not shown in the figure) is inserted into the three small round holes 452. By rotating the lower chuck body 45, the radial extension of the eight jaws 41 can be controlled, and the jaws 41 push the eight ring segments 43 to extend radially. When the lower chuck body 45 is rotated in the opposite direction to retract the jaws 41 radially, the elastic force of the arc spring 42 can press the ring segments 43 against the jaw key 412 of the jaws 41, completing the radial retraction of the ring segments 43. When the ring segments 43 are radially extended or retracted to the desired position, the driving tool is removed, and the locking nut 47 is tightened, completing the function of changing the required inner diameter of the bearing under test.

[0034] like Figure 9 As shown, in this embodiment, the outer diameter variable module 5 is coaxially arranged with the inner diameter variable module 4 described above (see...). Figure 10 The variable outer diameter module 5 includes a loading shell 51, an electric push rod 52, a mounting bracket 53, a first hinge 54, a second hinge 55, a second arc spring 56, a hinge shaft 57, a temperature sensor 58, and a vibration sensor 59. The loading shell 51 is fixed to the test platform 1 with screws, according to... Figure 1 The orientation of the hinge is such that its left and right planes are flush with the left and right planes of the ring 43, respectively. Four electric push rods 52 are evenly mounted on the inner ring. The push rods of the electric push rods 52 are threaded and fixedly connected to the threaded holes of the mounting bracket 53. The hinge shaft 57 passes through the through holes on the hinge piece 1 54, hinge piece 2 55, and mounting bracket 53 and is fixed to the mounting bracket 53. The other side of the hinge shaft 57 is fixed by a lock nut. Two arc-shaped springs 56 are connected to the inner end faces of the two hinge pieces, which are symmetrically distributed around the hinge shaft 57. Temperature sensors 58 and force sensors 34 are respectively mounted on the outer sides of the two hinge pieces above the loading shell 51, and a vibration sensor 59 is mounted on the outer side of the upper right hinge piece. During operation, the control element drives the four electric push rods 52 to synchronously retract radially, completing the outer diameter transformation function required for the bearing under test until each hinge clamps the outer ring of the bearing under test, with each hinge tangent to the outer ring, thus applying radial force to the bearing. Continuing to drive the four electric push rods 52 radially retracts increases the tangent angle between two hinges and the outer ring of the bearing under test, increasing the tension of the arc spring 56, and consequently increasing the radial force applied by the two hinges to the outer ring of the bearing under test. This can be adjusted to the required radial force for the test. The radial force, temperature, and vibration information of the bearing under test can be monitored through the force sensor 34, temperature sensor 58, and vibration sensor 59 on the hinges.

[0035] like Figure 11As shown, the bearing housing module 7 in this embodiment includes a bearing support frame 71, a deep groove ball bearing 72, and an elastic retaining ring 73. The bearing support frame 71 is fixed to the test platform 1 with screws, and has a through hole at its upper end. An annular groove is formed inside the left side of the through hole. The deep groove ball bearing 72 is installed in the through hole of the bearing support frame 71, and the elastic retaining ring 73 is embedded in the annular groove of the through hole to fix the outer ring of the deep groove ball bearing 72. The inner ring of the bearing is fixed on the other side of the deep groove ball bearing 72 through the shoulder of the spindle 6. The bearing housing module 7 is mainly used to support the spindle 6 and reduce the friction caused by direct contact between the spindle 6 and the bearing support frame 71.

[0036] Furthermore, the spindle 6 passes through the inner diameter variable module 4, the outer diameter variable module 5, and the bearing housing module 7 and is fixedly connected to the spindle coupling 8. The other side of the spindle coupling 8 is connected to the spindle motor 9, which is placed on the upper plate of the support frame 10. The central axis of the through hole of the axial loading module 3, the inner diameter variable module 4, the outer diameter variable module 5, and the bearing housing module 7 is aligned with the spindle axis.

[0037] like Figure 12 As shown, the spindle 6 has two shoulders 61 and two flat keys 62, and a certain length of external thread 63 is opened on the left cylindrical surface. The two shoulders 61 are used for axial positioning of the upper chuck body 44 and the deep groove ball bearing 72, respectively. The left flat key 62 is connected to the keyway of the central through hole 443 of the upper chuck body 44 to drive the rotation of the upper chuck body 44. The right flat key 62 is used to connect the spindle coupling 8, and the external thread 63 is connected to the fastening nut 47 to fix the chuck body and ensure that the chuck body rotates synchronously with the spindle 6.

[0038] The aforementioned device can be used to perform performance tests on rolling bearings capable of withstanding combined axial and radial loads and that can be installed individually. Typical rolling bearings include deep groove ball bearings and self-aligning roller bearings, and it can be used to simulate different operating conditions of the bearing. Self-aligning roller bearings can withstand a certain axial moment and are suitable for both conventional and off-center load conditions. Based on the aforementioned variable shaft diameter rolling bearing testing device, taking a self-aligning roller bearing as an example, the method for testing rolling bearings is as follows: 1. Start the lead screw motor to move the axial loading module on the support slider to a suitable distance, leaving reasonable space for the installation of the self-aligning roller bearing and the loading of the drive tool.

[0039] 2. Install the self-aligning roller bearing into the ring of the variable inner diameter module, with one side of the bearing against the shoulder of the ring. Loosen the fastening nut, use the drive tool to rotate the lower chuck body, causing the ring to expand until it fits against the inner ring of the bearing. Then remove the drive tool, tighten the fastening nut, and apply lubricating oil to the bearing using the oil supply nozzle.

[0040] 3. Use control elements to drive four electric push rods to retract radially synchronously until each hinge clamps the outer ring of the bearing. Based on the radial force observed by the force sensor on the hinge, decide whether to continue retracting the electric push rods to increase the radial force to meet the radial force required for the test.

[0041] 4. Restart the lead screw motor, move the axial loading module to a suitable position close to the bearing, adjust the oil supply pressure in the hydraulic cylinder of the axial loading module to adjust the telescopic column to the appropriate length, insert the pin to mechanically lock the movement of the telescopic column, and choose whether to continue to increase the oil supply pressure of the hydraulic cylinder according to the axial load required for the test. Adjust the pressure of the pressure regulating valve by adjusting the handle to adjust the axial force of the four hydraulic push rods to the required value. If the axial force is consistent, it can simulate the normal working condition. If the axial force is different, an additional axial bending moment can be added to simulate the off-center load condition. The magnitude of the value can be observed through the force sensor at the upper end of each hydraulic push rod. The hydraulic push rod extends under oil pressure and presses against the outer ring of the bearing to apply axial force.

[0042] 5. Start the spindle motor and set a reasonable speed. When the measured self-aligning roller bearing reaches the set speed or the values ​​of the temperature sensor and vibration sensor on the hinge exceed the set threshold, turn off the spindle motor, remove the measured bearing, and observe its fatigue characteristics.

[0043] 6. Return the device to its initial state, repeat the above steps, and load different test bearings to perform bearing performance tests.

[0044] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A variable shaft diameter rolling bearing testing device, comprising a testing platform, characterized in that, a screw drive module and an axial loading module are arranged at one end of the testing platform; an inner diameter variable module and an outer diameter variable module are arranged at the middle position; a bearing seat module, a main shaft, a main shaft motor and a support frame are arranged at the other end; the screw drive module is connected with the axial loading module, and is used to drive the axial loading module to move along the axial direction of the rolling bearing; the axial loading module is used to apply an axial force to the outer ring of the rolling bearing; the inner diameter variable module and the outer diameter variable module are coaxially arranged, and the inner diameter variable module is located in the inner ring of the outer diameter variable module; the main shaft motor is supported by the support frame, and the main shaft motor is connected with the main shaft, the main shaft is supported by the bearing seat module, and the main shaft is coaxially arranged with the inner diameter variable module and the outer diameter variable module.

2. The variable shaft diameter rolling element bearing testing apparatus of claim 1 wherein, the outer diameter variable module comprises a loading shell, an electric push rod, a mounting frame, a hinge piece one, a hinge piece two, an arc-shaped spring two, a hinge shaft, a temperature sensor, a force sensor and a vibration sensor; the loading shell is fixed on the testing platform by screws, and four equidistant electric push rods are arranged in the loading shell; the top pushing column of each electric push rod is connected with the mounting frame, and the hinge piece one and the hinge piece two are arranged on each mounting frame; the hinge shaft passes through the through holes of the hinge piece one, the hinge piece two and the mounting frame, so that the hinge piece one and the hinge piece two are fixed on the mounting frame; the inner side of the hinge piece one and the hinge piece two is connected with the arc-shaped spring two; the temperature sensor, the force sensor and the vibration sensor are arranged on different hinge pieces; each hinge piece is tangent to the outer ring of the bearing to be tested, and is used to apply a radial force to the bearing to be tested.

3. The variable shaft diameter rolling element bearing testing apparatus of claim 1 wherein, the inner diameter variable module comprises a jaw, an arc-shaped spring one, a ring petal, an upper chuck body, a lower chuck body, a pressure plate and a fastening nut; the upper chuck body, the lower chuck body, the pressure plate and the fastening nut are coaxially arranged in sequence, and the main shaft passes through the upper chuck body, the lower chuck body and the pressure plate in sequence and is threadedly connected with the fastening nut; the lower chuck body is connected with a driving tool, the upper chuck body is provided with a mounting groove for the radial movement of the jaw along the upper chuck body, and a plurality of jaws are slidably connected in the corresponding mounting grooves; the mounting groove provides accurate guidance for the linear movement of the jaw, so that the jaw can move radially accurately and stably. Meanwhile, the surface of the lower chuck body close to the upper chuck body is provided with a flat thread for connecting a limiting block at the bottom of the jaw; the radial extension end of the jaw is matched with the concave-convex inside of the ring petal; the two side end faces of each ring petal are connected by a pair of arc-shaped springs one, and a plurality of ring petals can be spliced into a complete circular ring.

4. The variable shaft diameter rolling element bearing testing apparatus of claim 3 wherein, The initial spacing of the limiting blocks of the plurality of jaws is slightly different, which is determined according to the flat thread of the lower chuck body, so as to ensure that the eight jaws are synchronously radially extended and retracted.

5. The variable diameter rolling element bearing testing apparatus of claim 3 wherein, The outer side of the plurality of ring petals is provided with shaft shoulders of the same height, which can be used for the subsequent axial fixation of the bearing to be tested.

6. The variable diameter rolling element bearing testing apparatus of claim 1 wherein, The axial loading module comprises a hydraulic cylinder, telescopic columns, a 90° elbow, a force sensor, a pressure regulating valve and a hydraulic push rod.

7. The variable diameter rolling element bearing testing apparatus of claim 1 wherein, The screw drive module comprises a screw motor, a support seat, a screw shaft coupling, a screw shaft, guide columns, a limiting block and a support sliding block.

8. The variable shaft diameter rolling element bearing testing apparatus of claim 1 wherein, The main shaft is connected with the main shaft motor through a main shaft coupling on one side, and passes through a bearing support frame and the inner diameter variable module on the other side.

9. The testing method of the variable diameter rolling bearing testing device according to any one of claims 1-8, characterized in that, Step 1: Start the screw drive module to move the axial loading module to a suitable distance to reserve reasonable space for the installation of the roller bearing and the loading of the driving tool; Step 2: Install the roller bearing into the ring petals of the inner diameter variable module, with one side of the bearing abutting against the shaft shoulder of the ring petals, loosen the fastening nuts, rotate the lower chuck body by using the driving tool to expand the ring petals to fit the inner ring of the bearing, then withdraw the driving tool, tighten the fastening nuts and apply lubricating oil to the bearing by using the oil supply nozzle; Step 3: Drive the outer diameter variable module to clamp the outer ring of the bearing by using the control element; Step 4: Adjust the axial loading module to make it contact with the outer ring of the roller bearing, and apply a set axial force to the outer ring of the bearing by the screw drive module; Step 5: Start the main shaft motor and set a reasonable rotating speed, when the measured roller bearing reaches a set number of rotations or the values of the temperature sensor and vibration sensor on the hinged piece exceed the set threshold, stop the main shaft motor, take out the measured bearing and observe its fatigue characteristics to complete the test.

10. The test method of a variable pitch rolling bearing test device according to claim 9, wherein, Restore the device to the initial state, install different test bearings, and the bearing performance test can be performed.

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