Rolling bearing friction torque measurement test bench

Abstract

The invention discloses a rolling bearing friction torque measurement test bench. A driving device of the test bench is fixedly mounted at the top of a base; the bearing adjusting and loading device is mounted at the top of the base and is opposite to the driving device; one end of the acting force measuring device can be rotatably mounted on the bearing adjusting and loading device around a horizontal axis, and is used for measuring the friction torque of a to-be-measured rolling bearing mounted in a measured unit; the measured unit is fixedly connected between the acting force measuring device and the driving device and is in butt joint through the same conical structures at the two ends. The bearing adjusting and loading device is used for applying an axial load and a radial load to the to-be-measured rolling bearing through the acting force measuring device and the measured unit; the driving device is used for driving the bearing inner ring and the bearing outer ring of the to-be-tested rolling bearing to rotate relatively. The test bench has the characteristics of simple mode switching, high loading precision and flexible operation.

Description

Technical Field

[0001] This invention belongs to the field of bearing testing technology, specifically relating to a rolling bearing friction torque measurement test bench, used to accurately measure the internal friction torque of bearings under combined loads and different rotational conditions. Background Technology

[0002] The frictional torque of rolling bearings is one of their core performance indicators, directly determining the starting performance, operating energy consumption, accuracy retention, and temperature rise control level of the main equipment. In aerospace, precision instruments, and high-end equipment fields, stringent requirements are placed on the precise control and prediction of bearing frictional torque. Therefore, during the bearing research and development and selection phase, accurately measuring the frictional torque under simulated real-world conditions through experimental methods plays an irreplaceable and crucial role in optimizing bearing design, verifying lubrication schemes, and improving system energy efficiency.

[0003] However, existing technologies and equipment for measuring bearing friction torque still have limitations in terms of the comprehensiveness of measurement functions, the flexibility of operating condition simulation, and the completeness of data acquisition, making it difficult to meet the needs of high-efficiency, multi-parameter R&D testing. Specifically, existing technologies each have their own focus but limited functionality. For example, the invention patent application with application number CN202422905915.9, application date of November 27, 2024, entitled "Bearing Friction Torque Measuring Instrument," mainly measures the peak static friction torque (starting torque) of a bearing from rest to the moment of startup. While its structure is relatively simple, it cannot measure and record the dynamic friction torque of the bearing under continuous and stable rotation, resulting in a relatively limited function. The utility model patent application with application number CN202422632679.8, application date October 30, 2024, and invention title "Rolling Bearing Friction Torque Testing Device" describes a testing device that can realize dynamic friction torque measurement under load. However, its loading method is usually relatively simple and it is difficult to conveniently realize complex working conditions that are closer to actual operation, such as axial loading or axial and radial combined loading.

[0004] In summary, existing technologies cannot fully meet the requirements for independent and comprehensive measurement of the frictional torque of rolling bearings under high precision and multiple operating conditions. They are insufficient to provide accurate data support for the performance evaluation of bearings under actual complex loads, and also insufficient to provide reliable experimental basis for the targeted optimization of their internal structures (such as rolling elements, cages, etc.). Summary of the Invention

[0005] To address the shortcomings of existing bearing friction torque testing benches, such as limited functionality, cumbersome mode switching, and insufficient loading accuracy, this invention provides a rolling bearing friction torque measurement testing bench that features simple mode switching, high loading accuracy, and flexible operation.

[0006] To achieve the above objectives, the present invention adopts the following specific technical solution:

[0007] A rolling bearing friction torque measuring test bench includes a base, a bearing adjustment and loading device, a force measuring device, a test unit, and a driving device. The drive device is fixedly installed on the top of the base; the bearing adjustment and loading device is installed on the top of the base and is arranged opposite to the drive device. One end of the force measuring device is rotatably mounted on the bearing adjustment and loading device around a horizontal axis, and is used to measure the friction torque of the rolling bearing to be tested installed in the unit under test; The unit under test is fixedly connected between the force measuring device and the driving device, and is docked through a tapered structure with the same two ends. The bearing adjustment loading device is used to apply axial load and radial load to the rolling bearing under test through the force measuring device and the measured unit; The driving device is used to drive the inner ring and outer ring of the rolling bearing under test to rotate relative to each other through the unit under test.

[0008] Furthermore, the unit under test includes a ferrule, an outer ring fixing end cap, a spindle, and a locking nut, all arranged coaxially. The ferrule has a cavity open at one end; the mandrel is placed inside the cavity of the ferrule; an annular space is formed between the inner wall surface of the ferrule and the outer wall surface of the mandrel; the rolling bearing to be tested is housed within the annular space; The outer ring fixing end cap is threadedly connected to the ferrule and is used to fix the outer ring of the rolling bearing to be tested inside the ferrule; the locking nut is threadedly connected to the mandrel and is used to fix the inner ring of the rolling bearing to be tested onto the mandrel. Both the ferrule and the spindle have tapered protrusions at their opposite ends; both the force measuring device and the drive device have tapered holes; the tapered holes and the tapered protrusions have the same taper; the tapered protrusions are inserted into the tapered holes, so that the rolling bearing to be tested is coaxially mounted with the force measuring device and the drive device, and the tapered protrusions and the tapered holes constitute the tapered structure; The ferrule, the spindle, the force measuring device, and the drive device are all provided with a central threaded hole; When the ferrule and the force measuring device, as well as the mandrel and the drive device, are fixedly connected by bolts threaded into the central threaded hole, the rolling bearing under test forms a test mode in which the outer ring of the bearing is fixed and the inner ring of the bearing rotates. When the ferrule and the drive device, as well as the spindle and the force measuring device, are fixedly connected by bolts threaded into the central threaded hole, the rolling bearing under test forms a test mode in which the inner ring of the bearing is fixed and the outer ring of the bearing rotates.

[0009] Furthermore, the inner wall surface of the ferrule is transitionally fitted with the outer ring of the rolling bearing to be tested; the inner end of the inner wall surface of the ferrule is provided with a limit stop, and the outer end of the inner wall surface is provided with an internal thread; the external thread of the outer ring fixing end cap is threadedly connected to the internal thread of the ferrule. The mandrel is a stepped shaft, consisting of a large-diameter section and a small-diameter section with different outer diameters; the large-diameter section has a shoulder at the end opposite to the small-diameter section; the small-diameter section has an external thread; the locking nut is threadedly connected to the external thread of the small-diameter section. The tapered protrusion is provided at the end of the smaller diameter section opposite to the larger diameter section and at the end of the ferrule opposite to the outer ring fixing end cap.

[0010] Furthermore, both the ferrule and the mandrel have stepped holes at their center.

[0011] Furthermore, the force measuring device includes a six-dimensional force sensor, a bearing connector, and a sensor mounting component; The six-dimensional force sensor has a fixed end and a measuring end. The fixed end is fixedly installed on one end of the sensor fixing member, and the measuring end is fixedly connected to one end of the bearing connecting member. The other end of the sensor fixture is rotatably mounted on the bearing adjustment and loading device. The bearing adjustment loading device has a lifting mechanism; the top end of the lifting mechanism abuts against the middle of the sensor fixing member, and is used to apply a radial load to the rolling bearing under test. The other end of the bearing connector is provided with a tapered hole and a central threaded hole coaxial with the tapered hole.

[0012] Furthermore, the drive device includes a drive motor, a drive spindle, a motor bracket, and a shaft support. Both the motor bracket and the shaft support are fixedly installed on the base; The drive motor is fixedly mounted on the motor bracket; One end of the drive spindle is coaxially and fixedly connected to the output shaft of the drive motor, the middle part is rotatably supported on the shaft support seat, and the other end is provided with a coaxial tapered hole and a central threaded hole.

[0013] Furthermore, the drive unit also includes a coupling, a deep groove ball bearing, a pair of high-precision angular contact ball bearings, a front bearing end cap, and a rear bearing end cap; The coupling is fixedly connected between the drive spindle and the output shaft; The deep groove ball bearing and the pair of high-precision angular contact ball bearings are installed in the shaft support seat to support the drive spindle; the front locking nut and the rear bearing end cap are respectively fixedly installed at both ends of the shaft support seat to lock the high-precision angular contact ball bearing and the deep groove ball bearing in the shaft support seat.

[0014] Furthermore, the bearing adjustment loading device also includes a translation plate, a handwheel, a threaded rod, a threaded rod support, a nut, and a bracket; The translational plate can be slidably mounted on the base along the axial direction of the drive spindle; The bottom end of the screw support is fixedly installed on the base; The nut, the bracket, and the lifting mechanism are fixedly installed on the translational plate from left to right; the threaded rod extends along the axial direction of the drive shaft, one end of which is fixedly installed with the handwheel and rotatably supported by the screw support seat, and the other end is screwed with the nut. The rotational motion of the handwheel is converted into the linear motion of the translational plate through the screwed engagement of the nut and the threaded rod, so as to realize the axial loading of the rolling bearing under test. The sensor fixture is rotatably mounted on the bracket.

[0015] Furthermore, the top surface of the base is provided with two parallel guide rails, which extend along the axial direction of the drive spindle. The bottom of the translational plate is provided with a slider that slides in cooperation with the guide rail; The translational plate is provided with two elongated holes that penetrate its thickness; The base is provided with a plurality of threaded holes opposite to the elongated hole, and the translational plate is fixedly connected to the base by bolts threaded to the threaded holes.

[0016] Compared with the prior art, the rolling bearing friction torque measurement test bench of the present invention has the following advantages: 1. The rolling bearing friction torque measurement test bench of the present invention achieves rapid and reliable switching of test modes, greatly improving testing efficiency and flexibility: Existing test benches have a fixed structure and typically only support one test mode: inner ring rotation and outer ring fixation. Switching to a test mode with outer ring rotation and inner ring fixation requires complex disassembly, reassembly, and precise realignment of the drive system, bearing clamping mechanism, and even the entire measurement frame, making the testing process cumbersome, time-consuming, and affecting the consistency and reliability of the test. The rolling bearing friction torque measurement test bench of the present invention creatively designs a test unit that can be installed as a whole by turning around. The drive end and measuring end of the test unit adopt a universal tapered interface with the same taper. When switching test modes, it is only necessary to remove the rolling bearing to be tested and the test unit used to clamp the rolling bearing as a whole module, rotate it 180°, and reinstall it. The tapered interface originally connected to the drive end is then connected to the measuring end, and vice versa. The conical structure simplifies the originally complex mechanical reconfiguration process into a standard operation that can be completed in a few minutes without replacing any core components, thus enabling a fast and reliable switch between two basic testing modes.

[0017] 2. The rolling bearing friction torque measurement test bench of this invention provides precise and stable axial and radial composite loading capabilities, more realistically simulating actual working conditions. Existing technologies often employ single radial loading methods such as levers and weights, failing to achieve independent and controllable composite application of the two loads. In this invention, radial loading is achieved through a lifting mechanism such as a jack integrated into the bearing adjustment loading device, while axial load is applied independently by the helical engagement of a threaded rod and nut driving a translational plate. Both can be independently controlled and set. This technical solution can stably and accurately simulate the complex load states experienced by bearings in actual applications. Because the loading path and measurement path are rigidly isolated and well-aligned, the additional torque interference introduced by the loading process itself is minimized, ensuring high fidelity of the friction torque measurement signal under composite loads.

[0018] 3. The rolling bearing friction torque measurement test bench of this invention constructs a high-precision, highly integrated direct measurement system, improving the accuracy and richness of the measurement data. Existing torque measurement methods suffer from indirectness, long transmission paths, or susceptibility to interference, making it difficult to simultaneously acquire multi-dimensional mechanical information. This invention directly connects a high-precision six-dimensional force sensor in series within the force transmission path of the bearing. One end of the six-dimensional force sensor is connected to the load application end, and the other end is directly connected to the bearing retaining ring through the bearing connector. This arrangement allows the six-dimensional force sensor to directly and without attenuation measure the reaction torque that prevents the bearing retaining ring from rotating. This torque value is equal to the internal friction torque of the bearing, resulting in the shortest measurement path, good dynamic response, and high accuracy. Furthermore, the six-dimensional force sensor not only provides the core friction torque but also simultaneously monitors force and torque components in other directions caused by minor assembly deviations or load fluctuations. This provides more comprehensive multi-dimensional force data for in-depth analysis of the bearing's operating status and diagnosis of test error sources, achieving an upgrade from single-parameter measurement to comprehensive condition monitoring.

[0019] 4. The rolling bearing friction torque measuring test bench of this invention features a safe and reliable non-destructive disassembly structure, enhancing the maintainability and operational safety of the equipment. Existing technologies often suffer from disassembly difficulties due to interference fits or slight deformations, and traditional hammering methods easily damage the mating surfaces, affecting accuracy and even damaging precision components such as sensors. The rolling bearing friction torque measuring test bench of this invention has a coaxial internal thread structure within the central holes of the ferrule and mandrel. When the conical surface is locked and disassembly is required, the small-diameter connecting bolt used for fastening can be unscrewed first, followed by screwing in a larger ejector bolt. Tightening the ejector bolt will allow the clamping part to be smoothly and vertically ejected from the conical hole. This design completely avoids forceful disassembly, achieving non-destructive separation of key mating surfaces with standardized and simple tools, solving the maintenance problem of conical surface connections. This not only protects the fitting accuracy of core components and extends equipment life but also greatly improves operational safety and convenience, reducing maintenance costs and technical barriers. Attached Figure Description

[0020] Figure 1 This is a three-dimensional structural schematic diagram of the rolling bearing friction torque measurement test bench of the present invention; Figure 2 This is a front view of the rolling bearing friction torque measuring test bench of the present invention; Figure 3 This is a cross-sectional view of the unit under test.

[0021] Figure label: 1-Base, 11-Loading sub-seat, 12-Drive sub-seat, 13-Guide rail; 2-Bearing adjustment loading device, 21-Translation plate, 211-Elongated hole, 22-Handwheel, 23-Threaded rod, 24-Screw support seat, 25-Nut, 26-Bracket, 27-Lifting mechanism; 3-Force measuring device, 31-Six-dimensional force sensor, 32-Bearing connector, 33-Sensor fixing component; 4-Measured unit, 41-Cladle, 411-First conical protrusion, 42-Outer ring fixing end cap, 43-Mandrel, 431-Second conical protrusion, 44-Locking nut; 5-Drive device, 51-Drive motor, 52-Drive spindle, 53-Motor bracket, 54-Shaft support seat, 55-Coupling; 6-Rolling bearing to be measured. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] In the description of this invention, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances. Furthermore, in the description of this invention, unless otherwise stated, "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0024] This embodiment provides a rolling bearing friction torque measurement test bench, such as Figure 1 and Figure 2As shown in the structure, the test bench includes a base 1, a bearing adjustment loading device 2, a force measuring device 3, a test unit 4, and a drive device 5. The bearing adjustment loading device 2, force measuring device 3, test unit 4, and drive device 5 are distributed sequentially from left to right, with drive device 5 fixedly mounted on the top of base 1, and bearing adjustment loading device 2 also mounted on the top of base 1. Bearing adjustment loading device 2 and drive device 5 are positioned opposite each other. Bearing adjustment loading device 2 is used to apply axial and radial loads to the rolling bearing 6 under test via force measuring device 3 and test unit 4. One end of force measuring device 3 is rotatably mounted on bearing adjustment loading device 2 around a horizontal axis, used to measure the frictional torque of the rolling bearing 6 under test installed in test unit 4. Test unit 4 is fixedly connected between force measuring device 3 and drive device 5, and is connected via identical tapered structures at both ends. Drive device 5 is used to drive the inner and outer rings of the rolling bearing 6 under test to rotate relative to each other via test unit 4.

[0025] like Figure 1 and Figure 2 As shown, the base 1 is the installation foundation and load-bearing body of the entire test bench. Its top is divided into two functional areas along the length direction: the left part is the loading seat 11 and the right part is the drive seat 12. The top of the loading seat 11 is precision machined with two parallel guide rails 13, which provide guidance for the bearing adjustment loading device 2. The top of the drive seat 12 is fixed with the base of the drive device 5 by bolts to ensure that the axis of the drive spindle 52 is parallel to the sliding direction of the guide rail 13.

[0026] like Figure 3 As shown, the unit under test 4 includes a ferrule 41, an outer ring fixing end cap 42, a spindle 43, and a locking nut 44, all coaxially arranged. The ferrule 41 has a cavity with one open end. The spindle 43 is placed inside the cavity of the ferrule 41. An annular space is formed between the inner wall of the ferrule 41 and the outer wall of the spindle 43. The rolling bearing 6 to be tested is housed in the annular space. The outer ring fixing end cap 42 is threadedly connected to the ferrule 41 to fix the outer ring of the rolling bearing 6 to be tested inside the ferrule 41. The locking nut 44 is threadedly connected to the spindle 43 to fix the inner ring of the rolling bearing 6 to be tested onto the spindle 43. The ferrule 41 and the spindle 43 each have a conical protrusion at the center of their opposite ends, and the outer circumferential surface of the conical protrusion is a conical surface. Figure 3As shown, the ferrule 41 has a first tapered protrusion 411 at the center of its end opposite to the spindle 43, and the spindle 43 has a second tapered protrusion 431 at the center of its end opposite to the ferrule 41. Both the force measuring device 3 and the drive device 5 have tapered holes. The tapered hole of the force measuring device 3 is formed at the end of the bearing connector 32 facing the rolling bearing 6 to be tested. The tapered hole of the drive device 5 is formed at the end of the drive spindle 52 facing the rolling bearing 6 to be tested. The tapered holes and the tapered protrusions have the same taper. The tapered protrusions are inserted into the tapered holes, and the tapered fit enables the rolling bearing 6 to be tested to be coaxially mounted with the force measuring device 3 and the drive device 5. The tapered protrusion and tapered hole constitute a tapered structure; the ferrule 41, spindle 43, force measuring device 3, and drive device 5 are all provided with a central threaded hole; when the ferrule 41 and the force measuring device 3, and the spindle 43 and the drive device 5 are respectively fixedly connected by bolts threaded into the central threaded hole, the rolling bearing 6 under test forms a test mode in which the outer ring of the bearing is fixed and the inner ring of the bearing rotates; when the ferrule 41 and the drive device 5, and the spindle 43 and the force measuring device 3 are respectively fixedly connected by bolts threaded into the central threaded hole, the rolling bearing 6 under test forms a test mode in which the inner ring of the bearing is fixed and the outer ring of the bearing rotates. The inner wall of the ferrule 41 has a transition fit with the outer ring of the rolling bearing 6 under test; the inner end of the inner wall of the ferrule 41 is provided with a limit stop, and the outer end of the inner wall is provided with an internal thread; the external thread of the outer ring fixing end cap 42 is threadedly connected to the internal thread of the ferrule 41; the spindle 43 is a stepped shaft, composed of a large-diameter section and a small-diameter section with different outer diameters; the large-diameter section has a shoulder at the end opposite to the small-diameter section; the small-diameter section is provided with an external thread; the locking nut 44 is threadedly connected to the external thread of the small-diameter section; the small-diameter section at the end opposite to the large-diameter section and the ferrule 41 at the end opposite to the outer ring fixing end cap 42 are both provided with tapered protrusions. The center threaded holes of the ferrule 41 and the spindle 43 are both stepped holes, which are connected to the bearing connector 32 or the drive spindle 52 through the threaded holes with smaller diameters and bolts.

[0027] like Figure 3As shown, the unit under test 4 is the part that directly mounts the rolling bearing 6 to be tested and realizes the mode switching function. The rolling bearing 6 to be tested is the rolling bearing to be tested, such as a deep groove ball bearing or an angular contact ball bearing. The ferrule 41 is an annular sleeve. The inner hole of the ferrule 41 and the outer ring of the rolling bearing 6 to be tested adopt an transition fit. Its outer end is machined with a precision outer conical surface that matches the tapered hole of the drive spindle 52, forming a reliable tapered interference fit. The mandrel 43 is a key component for realizing the quick switching function. Its main body is a stepped shaft. The shoulder is used to position the inner ring of the rolling bearing 6 to be tested and locks the inner ring of the rolling bearing 6 to be tested through a locking nut 44. Its precision outer conical surface is exactly the same as the conical surface of the ferrule 41 and can match the tapered hole of the bearing connector 32. This design, which has the same conical surface structure at the outer ends of both the ferrule 41 and the mandrel 43, allows it to be used in reverse. To facilitate disassembly of the tapered connection that may jam due to interference fit, the center of the ferrule 41 and the spindle 43 is also provided with an internal thread that is coaxial with the connecting thread but has a larger diameter. When it is necessary to disassemble the unit under test 4, the small-diameter connecting bolt can be completely unscrewed first, and then an ejector bolt with a diameter matching the large thread hole can be screwed into this large thread hole. Continue to tighten the ejector bolt, and its front end will press against the center plane of the bearing connector 32 or the end face of the drive spindle 52. The resulting reverse axial force can smoothly eject the ferrule or spindle 43 from the tapered hole, achieving a non-destructive and safe separation.

[0028] like Figure 1 and Figure 2 As shown, the force measuring device 3 includes a six-dimensional force sensor 31, a bearing connector 32, and a sensor fixing member 33. The six-dimensional force sensor 31 has a fixed end and a measuring end. The fixed end is fixedly installed on one end of the sensor fixing member 33, and the measuring end is fixedly connected to one end of the bearing connector 32, and is integrated with the fixing ring of the rolling bearing 6 to be tested through the bearing connector 32. The other end of the sensor fixing member 33 is rotatably installed on the bearing adjusting loading device 2. The bearing adjusting loading device 2 has a lifting mechanism 27. The top end of the lifting mechanism 27 abuts against the middle of the sensor fixing member 33 to apply a radial load to the rolling bearing 6 to be tested. The other end of the bearing connector 32 is provided with a tapered hole and a central threaded hole coaxial with the tapered hole. The sensor fixing member 33 is rotatably installed on the bracket 26 of the bearing adjusting loading device 2 via a horizontally oriented rotating shaft, so that the sensor fixing member 33 can rotate around the rotating shaft to facilitate the radial loading of the lifting mechanism 27. like Figure 1 and Figure 2As shown, the drive unit 5 includes a drive motor 51, a drive spindle 52, a motor bracket 53, a shaft support 54, a coupling 55, a deep groove ball bearing, a pair of high-precision angular contact ball bearings, a front bearing end cover, and a rear bearing end cover. The motor bracket 53 and the shaft support 54 are both fixedly mounted on the base 1. The drive motor 51 is fixedly mounted on the motor bracket 53. One end of the drive spindle 52 is coaxially and fixedly connected to the output shaft of the drive motor 51, and its middle section is rotatably supported on the shaft support 54. The other end is provided with a coaxial tapered hole and a central threaded hole. The coupling 55 is fixedly connected between the drive spindle 52 and the output shaft. The deep groove ball bearing and a pair of high-precision angular contact ball bearings are installed inside the shaft support 54 to support the drive spindle 52. The front bearing end cover and the rear bearing end cover are respectively fixedly installed at both ends of the shaft support 54 to lock the high-precision angular contact ball bearings and the deep groove ball bearings inside the shaft support 54.

[0029] The aforementioned drive device 5 provides rotational drive for the test, and the rotating ring of the rolling bearing 6 to be tested is installed. The rotating ring can be either the inner ring or the outer ring of the bearing. Figure 3 The diagram illustrates the rotation of the bearing inner ring. The drive motor 51 is a servo motor, mounted on the drive sub-base 12 of the base 1 via a motor bracket 53, providing power for precise speed and direction control. The shaft support 54 is bolted to the drive sub-base 12 of the base 1 and contains a pair of high-precision angular contact ball bearings and a deep groove ball bearing, with the deep groove ball bearing positioned between the pair of high-precision angular contact ball bearings. The drive spindle 52 is supported by the shaft support 54 and its internal pair of high-precision angular contact ball bearings and deep groove ball bearing. The drive spindle 52 is connected to the output shaft of the drive motor 51 via a coupling 55. The free end of the drive spindle 52 (facing the test unit) has a precision tapered hole, the taper of which perfectly matches the taper of the outer tapered surface of the mandrel 43 and the sleeve 41. The front bearing end cap and the rear bearing end cap are fixedly installed at both ends of the shaft support 54 by bolts, and are used to lock the angular contact ball bearing and deep groove ball bearing inside the shaft support 54.

[0030] like Figure 1 and Figure 2As shown, the bearing adjustment loading device 2 also includes a translational plate 21, a handwheel 22, a threaded rod 23, a screw support 24, a nut 25, and a bracket 26. The translational plate 21 is slidably mounted on the base 1 along the axial direction of the drive shaft 52. The bottom end of the screw support 24 is fixedly mounted on the base 1. The nut 25, the bracket 26, and the lifting mechanism 27 are fixedly mounted on the translational plate 21 from left to right. The threaded rod 23 extends along the axial direction of the drive shaft 52. One end is fixedly mounted with the handwheel 22 and rotatably supported by the screw support 24. The other end is screwed into the nut 25. The screwed engagement between the nut 25 and the threaded rod 23 converts the rotational motion of the handwheel 22 into the linear motion of the translational plate 21, which is used to realize the axial loading of the rolling bearing 6 under test. The sensor fixing part 33 is rotatably mounted on the bracket 26. The top surface of the base 1 is provided with two parallel guide rails 13, which extend along the axial direction of the drive spindle 52; the bottom of the translational plate 21 is provided with a slider that slides with the guide rails 13; the translational plate 21 is provided with two elongated holes 211 that penetrate its thickness; the base 1 is provided with multiple threaded holes opposite to the elongated holes 211, and the translational plate 21 is fixedly connected to the base 1 by bolts that are threaded to the threaded holes.

[0031] The bearing adjustment loading device 2 is mounted on the guide rail 13 of the loading seat 11. Its core function is to clamp the fixed ring of the rolling bearing 6 to be tested. Depending on the test mode, the fixed ring can be the outer ring or the inner ring of the bearing, and apply a precise and controllable axial load and / or radial load to the fixed ring. The translation plate 21 has four sliders at the bottom. The sliders are precisely matched with the guide rail 13, so that the translation plate 21 can move and be positioned smoothly along the axial direction. The rotation of the handwheel 22 drives the threaded rod 23 to rotate. The rotation of the handwheel 22 is converted into the axial movement of the translation plate 21 along the threaded rod 23 through the threaded engagement of the threaded rod 23 and the nut 25. This can also be used to apply an axial load. During the test, the position can be locked by two bolts, that is, the translation plate 21 is fixedly connected to the base 1 and the loading seat 11 by two bolts. The jack serves as the lifting mechanism 27, with the bottom of its cylinder fixed on the translational plate 21. Taking a mechanical screw jack as an example, the top surface of its push rod contacts the bottom of the sensor fixing part 33. By manually driving the rotation of the jack's screw sleeve, the push rod can lift the entire sensor fixing part 33 and the force measuring device 3 and the measured unit 4 connected to it, thereby applying a stable, adjustable, and large radial load to the fixed ring of the rolling bearing 6 to be measured.

[0032] The above-mentioned test bench can realize the following two test modes: Test Mode 1 In the bearing inner ring rotation and outer ring fixation mode: The rolling bearing 6 to be tested is fitted onto the mandrel 43 and positioned using the shaft shoulder; one end of the mandrel 43 is inserted into the tapered hole at the end of the drive spindle 52, and the locking bolt is tightened to rigidly connect the bearing inner ring to the drive spindle 52. The tapered surface of the ferrule 41 is fitted with the tapered hole of the bearing connector 32 to rigidly connect the bearing outer ring to the force measuring device 3. The axial position and axial load of the entire force measuring device 3 are adjusted by the handwheel 22. The drive motor 51 is started, driving the spindle 52 to rotate the bearing inner ring; the frictional torque on the bearing outer ring is transmitted to the six-dimensional force sensor 31 through the ferrule 41 and is accurately measured, and the jack can apply a radial load.

[0033] Test Mode 2 Bearing outer ring rotation, bearing inner ring fixed mode: Remove the mandrel 43 from the drive spindle 52 and remove the ferrule 41 from the measuring side; rotate the measured unit 4 180° so that the conical surface of the mandrel 43 is inserted into the conical hole of the bearing connector 32 and locked with bolts, the bearing inner ring is fixed on the measuring side; then mate the outer conical surface of the ferrule 41 with the conical hole at the end of the drive spindle 52 and lock with bolts; at this time, the bearing outer ring is fixedly connected to the drive spindle 52; start the drive motor 51, at this time the drive spindle 52 drives the bearing outer ring to rotate and the bearing inner ring to be fixed; the frictional torque acting on the bearing inner ring is transmitted to the six-dimensional force sensor 31 through the mandrel 43; the load application method remains unchanged.

[0034] In the above embodiments, when the rolling bearing 6 under test is in the mode of inner ring rotation and outer ring fixation, the fixed ring is the outer ring of the rolling bearing 6 under test, and the rotating ring is the inner ring of the rolling bearing 6 under test. That is, at this time, the ferrule 41 is fixedly connected to the bearing connector 32, and the spindle 43 is fixedly connected to the drive spindle 52. When the rolling bearing 6 under test is in the mode of outer ring rotation and inner ring fixation, the rotating ring is the outer ring of the rolling bearing 6 under test, and the fixed ring is the inner ring of the rolling bearing 6 under test. At this time, the ferrule 41 is fixedly connected to the drive spindle 52 through a tapered surface fit and bolts, and the spindle 43 is also fixedly connected to the bearing connector 32 through a tapered surface fit and bolts.

[0035] Using the aforementioned test bench, the application of axial and radial loads is independent and does not interfere with each other. The radial load is applied directly to the bearing retaining ring by the jack through the six-dimensional force sensor 31, while the axial load is applied by rotating the handwheel 22. The six-dimensional force sensor 31 can distinguish and independently output the torque generated by friction and the force components generated by the radial / axial loads, ensuring the purity and accuracy of the torque measurement.

[0036] Obviously, those skilled in the art can make various modifications and variations to the embodiments of the present invention without departing from the spirit and scope of the invention. Therefore, if these modifications and variations fall within the scope of the claims of the present invention and their equivalents, the present invention also intends to include these modifications and variations.

[0037] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. 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 test bench for measuring the frictional torque of rolling bearings, characterized in that, Includes a base, a bearing adjustment and loading device, a force measuring device, a measured unit, and a drive device; The drive device is fixedly installed on the top of the base; the bearing adjustment and loading device is installed on the top of the base and is arranged opposite to the drive device. One end of the force measuring device is rotatably mounted on the bearing adjustment and loading device around a horizontal axis, and is used to measure the friction torque of the rolling bearing to be tested installed in the unit under test; The unit under test is fixedly connected between the force measuring device and the driving device, and is positioned by a tapered structure with the same shape at both ends. The bearing adjustment loading device is used to apply axial load and radial load to the rolling bearing under test through the force measuring device and the measured unit; The driving device is used to drive the inner ring and outer ring of the rolling bearing under test to rotate relative to each other through the unit under test.

2. The test bench as described in claim 1, characterized in that, The unit under test includes a ferrule, an outer ring fixing end cap, a spindle, and a locking nut, all arranged coaxially. The ferrule has a cavity open at one end; the mandrel is placed inside the cavity of the ferrule; an annular space is formed between the inner wall surface of the ferrule and the outer wall surface of the mandrel; the rolling bearing to be tested is housed within the annular space; The outer ring fixing end cap is threadedly connected to the ferrule and is used to fix the outer ring of the rolling bearing to be tested inside the ferrule; the locking nut is threadedly connected to the mandrel and is used to fix the inner ring of the rolling bearing to be tested onto the mandrel. Both the ferrule and the spindle have tapered protrusions at their opposite ends; both the force measuring device and the drive device have tapered holes; the tapered holes and the tapered protrusions have the same taper; the tapered protrusions are inserted into the tapered holes, so that the rolling bearing to be tested is coaxially mounted with the force measuring device and the drive device, and the tapered protrusions and the tapered holes constitute the tapered structure; The ferrule, the spindle, the force measuring device, and the drive device are all provided with a central threaded hole; When the ferrule and the force measuring device, as well as the mandrel and the drive device, are fixedly connected by bolts threaded into the central threaded hole, the rolling bearing under test forms a test mode in which the outer ring of the bearing is fixed and the inner ring of the bearing rotates. When the ferrule and the drive device, as well as the spindle and the force measuring device, are fixedly connected by bolts threaded into the central threaded hole, the rolling bearing under test forms a test mode in which the inner ring of the bearing is fixed and the outer ring of the bearing rotates.

3. The test bench as described in claim 2, characterized in that, The inner wall surface of the ferrule is transitionally fitted with the outer ring of the rolling bearing to be tested; the inner end of the inner wall surface of the ferrule is provided with a limit stop, and the outer end of the inner wall surface is provided with an internal thread; the external thread of the outer ring fixing end cap is threadedly connected to the internal thread of the ferrule. The mandrel is a stepped shaft, consisting of a large-diameter section and a small-diameter section with different outer diameters; the large-diameter section has a shoulder at the end opposite to the small-diameter section; the small-diameter section has an external thread; the locking nut is threadedly connected to the external thread of the small-diameter section. The tapered protrusion is provided at the end of the smaller diameter section opposite to the larger diameter section and at the end of the ferrule opposite to the outer ring fixing end cap.

4. The test bench as described in claim 2, characterized in that, Both the ferrule and the mandrel have stepped holes in their center.

5. The test bench as described in claim 1, characterized in that, The force measuring device includes a six-dimensional force sensor, a bearing connector, and a sensor fixing component; The six-dimensional force sensor has a fixed end and a measuring end. The fixed end is fixedly installed on one end of the sensor fixing member, and the measuring end is fixedly connected to one end of the bearing connecting member. The other end of the sensor fixture is rotatably mounted on the bearing adjustment and loading device. The bearing adjustment loading device has a lifting mechanism; the top end of the lifting mechanism abuts against the middle of the sensor fixing member, and is used to apply a radial load to the rolling bearing under test. The other end of the bearing connector is provided with a tapered hole and a central threaded hole coaxial with the tapered hole.

6. The test bench as described in claim 1, characterized in that, The drive device includes a drive motor, a drive spindle, a motor bracket, and a shaft support. Both the motor bracket and the shaft support are fixedly installed on the base; The drive motor is fixedly mounted on the motor bracket; One end of the drive spindle is coaxially and fixedly connected to the output shaft of the drive motor, the middle part is rotatably supported on the shaft support seat, and the other end is provided with a coaxial tapered hole and a central threaded hole.

7. The test bench as described in claim 6, characterized in that, The drive unit also includes a coupling, a deep groove ball bearing, a pair of high-precision angular contact ball bearings, a front bearing end cap, and a rear bearing end cap; The coupling is fixedly connected between the drive spindle and the output shaft; The deep groove ball bearing and the pair of high-precision angular contact ball bearings are installed in the shaft support seat to support the drive spindle; the front locking nut and the rear bearing end cap are respectively fixedly installed at both ends of the shaft support seat to lock the high-precision angular contact ball bearing and the deep groove ball bearing in the shaft support seat.

8. The test bench as described in any one of claims 1-7, characterized in that, The bearing adjustment and loading device also includes a translation plate, a handwheel, a threaded rod, a threaded rod support, a nut, and a bracket; The translational plate can be slidably mounted on the base along the axial direction of the drive spindle; The bottom end of the screw support is fixedly installed on the base; The nut, the bracket, and the lifting mechanism are fixedly installed on the translational plate from left to right; the threaded rod extends along the axial direction of the drive shaft, one end of which is fixedly installed with the handwheel and rotatably supported by the screw support seat, and the other end is screwed with the nut. The rotational motion of the handwheel is converted into the linear motion of the translational plate through the screwed engagement of the nut and the threaded rod, so as to realize the axial loading of the rolling bearing under test. The sensor fixture is rotatably mounted on the bracket.

9. The test bench as described in claim 8, characterized in that, The top surface of the base is provided with two parallel guide rails, which extend along the axial direction of the drive spindle. The bottom of the translational plate is provided with a slider that slides in cooperation with the guide rail; The translational plate is provided with two elongated holes that penetrate its thickness; The base is provided with a plurality of threaded holes opposite to the elongated hole, and the translational plate is fixedly connected to the base by bolts threaded to the threaded holes.

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