An automated apparatus for measuring the rotational torque of a frame pivot bearing

Abstract

The present application relates to the technical field of precision measurement and automation testing, and particularly relates to an automatic equipment for measuring rotational torque of a bearing of a rotating shaft of a frame, comprising a servo driving unit for providing controllable rotary drive, a high-precision sensing unit for real-time monitoring of rotary angle position and detecting micro-torque signals, and an execution control unit for fixing of a workpiece to be measured, releasing and switching of a measuring point during measurement. Through cooperation of multiple components in the high-precision sensing unit, based on action of the execution control unit, the first torque detection module is driven to retract, the second torque detection module is driven to extend, the probe is brought into contact with the same position of the inner frame, and finally the servo motor is rotated until the inner and outer frames cross the overlapping area. For the overlapping dead zone, the system is switched to the second torque detection module for data acquisition, thus solving the problem that a specific area cannot be measured due to mechanical interference, and realizing full-circle continuous and blind-area-free measurement of torque detection.

Description

Technical Field

[0001] This invention relates to the field of precision measurement and automated testing technology, specifically to an automated device for measuring the rotational torque of frame shaft bearings. It is suitable for precision shaft systems with inner and outer frame structures, such as ultra-precision bearings, micro motors, and aerospace attitude control mechanisms, where there are strict requirements for torque distribution. Background Technology

[0002] The rotational torque of the frame shaft bearing is one of the key parameters for evaluating the performance of rotating machinery systems. Especially in high-precision applications such as precision transmission, inertial navigation, and aerospace mechanisms, the completeness and efficiency of its measurement directly affect the reliability and lifespan of the product.

[0003] Currently, the measurement of the rotational torque of frame shaft bearings mainly faces the following technical challenges: Traditional manual measuring equipment, such as mechanical pointer torque meters or dial torque wrenches, relies on manual reading of pointer deflection angles or scale values. While these devices are simple in structure and low in cost, they have significant drawbacks: First, they rely on human visual interpretation, introducing visual errors and subjective biases; second, the measurement process is entirely manual, resulting in low efficiency, poor repeatability, and an inability to achieve continuous, multi-turn measurements; third, the mechanical structure is prone to wear and vibration, lacking long-term stability, and is particularly unable to address the measurement dead zone problem that occurs during the rotation of shafts with inner and outer frame structures.

[0004] Semi-automatic measurement systems: These systems typically use motors to drive the rotation of the workpiece under test, but manual intervention is still required for positioning, alignment, or data recording. While this improves measurement consistency to some extent, it still suffers from low automation, long measurement cycles, and high reliance on operator skills. More importantly, existing semi-automatic systems lack the ability to automatically identify and compensate for interference areas in frame structures, resulting in missing measurement data in critical areas.

[0005] Existing high-precision measurement solutions: Some existing high-precision measurement solutions attempt to improve measurement performance by improving sensor accuracy or control algorithms. However, these solutions mostly focus on improving measurement accuracy in a single direction and do not fundamentally solve the problem of continuous measurement throughout the entire circumference caused by mechanical interference. Especially for shaft structures with inner and outer frames, when the inner and outer frames rotate to the overlapping area, traditional measurement methods cannot effectively deploy sensors, resulting in a measurement dead zone in this area, making it impossible to obtain complete torque distribution data. Furthermore, existing equipment often lacks highly integrated automatic actuators, making it difficult to achieve full automation of the measurement process.

[0006] The underlying reasons for the above problems are: First, the existing equipment lacks high-precision angle synchronization feedback and automatic execution mechanism, making it impossible to accurately judge the measurement point and automatically avoid it. Secondly, the mechanical structure does not consider a dead zone measurement mechanism and cannot handle the measurement of overlapping sections of the frame.

[0007] Therefore, there is an urgent need in this field for an automated frame shaft bearing rotation torque measuring device that can integrate high-precision sensing, has the ability to automatically identify and measure dead zones, and achieve continuous measurement throughout the entire circumference, in order to overcome the limitations of existing technologies in terms of dead zone measurement and automation. Summary of the Invention

[0008] This invention addresses the technical problems existing in the prior art by providing an automated device for measuring the rotational torque of a frame shaft bearing.

[0009] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: an automated device for measuring the rotational torque of a frame shaft bearing, comprising a servo drive unit for providing controllable rotational drive; A high-precision sensing unit is used to monitor the rotational angular position and detect micro-torque signals in real time; The execution control unit is used for fixing and releasing the workpiece under test and switching measurement points during the measurement process; The high-precision sensing unit is signal-connected to the execution control unit and works in coordination based on real-time angular position information to achieve continuous torque measurement of the workpiece without dead zones throughout its entire circumference. The high-precision sensing unit includes a second torque detection module, which is located at the axial direction of the workpiece and is used to detect the axial load when the inner and outer frames of the workpiece are in the overlap dead zone. The execution control unit includes an electric push rod, a displacement sensor, and a guide rod; It also includes a limiting unit, used to detect the contact force of the second torque detection module with the workpiece.

[0010] In a preferred embodiment, the servo drive unit includes a servo motor, a planetary reducer connected to the output shaft of the servo motor, and a coupling disposed at the output end of the planetary reducer. A connecting member is fixedly connected to the output end of the coupling, and a workpiece clamp is sleeved on the surface of the connecting member.

[0011] In a preferred embodiment, the servo drive unit further includes a mounting frame, the servo motor, planetary reducer and coupling are all disposed on the lower surface of the mounting frame, and the connecting parts are rotatably connected to the mounting frame. The workpiece fixture is fixedly connected to the mounting frame, and counterweights are provided on both sides of the lower surface of the mounting frame.

[0012] In a preferred embodiment, the high-precision sensing unit further includes: A hollow angle encoder is non-contactly mounted on the rotating shaft of a workpiece fixture to monitor the rotation angle of a workpiece rigidly connected inside the fixture in real time. The first torque detection module, driven by the output end of an electric push rod, can extend between the inner and outer frames of the workpiece to detect tangential micro-torque.

[0013] In a preferred embodiment, the first torque detection module includes a pointer fixedly connected to the output end of the electric push rod and a sensor disposed on the surface of the pointer. The second torque detection module includes a probe set perpendicular to the pointer and an axial force sensor connected to the probe. The sensor and the axial force sensor operate based on the strain measurement principle to ensure that the deformation is within the elastic range during the measurement process.

[0014] In a preferred embodiment, the electric push rod is fixedly mounted on the mounting frame, and the output end of the electric push rod is fixedly connected to the pointer. The displacement sensor is fixedly connected to the output end of the electric push rod and is set perpendicular to the pointer. The displacement sensor is slidably sleeved on the surface of the guide rod, and the guide rod is fixedly connected to the electric push rod.

[0015] In a preferred embodiment, the execution control unit further includes a guide tube fixedly disposed on the upper surface of the mounting frame. The guide tube has a push rod fixedly connected to the probe inside. The push rod is slidably disposed with the guide tube, and the push rod has the same stroke as the output end of the electric push rod.

[0016] In a preferred embodiment, the execution control unit further includes two sliding blocks that are respectively fixedly connected to the lower surface of the push rod and the output end of the electric push rod. The surfaces of the sliding blocks are each fixedly connected to elastic elements that are fixedly connected to the mounting frame, and the sliding blocks are slidably connected to the mounting frame. The surfaces of the two sliding blocks are together attached to a drive plate that is rotatably disposed on the surface of the mounting frame.

[0017] In a preferred embodiment, the limiting unit includes arc-shaped plates that are slidably arranged in a circular array inside the workpiece fixture. The outer arc surface of the arc-shaped plates is symmetrically provided with elastic rods that are fixedly connected to the workpiece fixture. Pressure sensors are fixedly connected to one side of each of the two arc-shaped plates, and the two pressure sensors are respectively arranged perpendicular to the probe and the pointer.

[0018] In a preferred embodiment, through slots are provided on both sides of the surface of the workpiece fixture, and the through slots are arranged opposite to the probe and the pointer. The upper surfaces of the probe and the pointer are fixedly connected with a clamping plate. The clamping plate can be attached to a pressure sensor through the through slot to detect the force of the probe and the pointer in contact with the workpiece.

[0019] The beneficial effects of this invention are: This device, through the coordinated operation of a high-precision sensing unit and multiple components in the execution control unit, enables the system to immediately coordinate the action of the execution control unit when the workpiece rotates to a preset critical angle where mechanical interference is about to occur between the inner and outer frames. This drives the first torque detection module to retract and the second torque detection module to extend, allowing it to re-contact the same position of the inner frame from a direction perpendicular to the first torque detection module. Finally, the servo motor continues to rotate until the inner and outer frames cross the overlapping area. For the overlapping dead zone, the system automatically switches to the second torque detection module for data acquisition. After completion, all rotational torque and angle data are fused to generate a complete torque-angle curve, solving the problem of mechanical interference causing measurement failure in specific areas and achieving continuous, blind-zone-free torque measurement throughout the entire circumference. From workpiece clamping and positioning, low-speed rotation, and automatic switching from critical point to data acquisition and processing, the entire process requires no manual intervention, ensuring high consistency and repeatability of measurement results, reducing reliance on operator skills, and automating the detection of rotational torque of frame shaft bearings. The fully automated operation process avoids the time spent on repeated manual adjustments, alignment, and readings, shortens the single measurement cycle, and improves overall measurement efficiency. Attached Figure Description

[0020] Figure 1 This is a front structural schematic diagram of an automated device for measuring the rotational torque of a frame shaft bearing, as proposed in this invention. Figure 2 This is a side view of an automated device for measuring the rotational torque of a frame shaft bearing, as proposed in this invention. Figure 3 This is a schematic diagram of the first torque detection module, mounting frame, and execution control unit of an automated device for measuring the rotational torque of a frame shaft bearing, as proposed in this invention. Figure 4 This is a schematic diagram of the first torque detection module, the second torque detection module, and the drive plate structure of an automated device for measuring the rotational torque of a frame shaft bearing, as proposed in this invention. Figure 5 This is a schematic diagram of a workpiece fixture and an arc-shaped plate assembly structure for an automated device for measuring the rotational torque of a frame shaft bearing, as proposed in this invention. Figure 6 This is a schematic diagram of the limit unit structure of an automated device for measuring the rotational torque of a frame shaft bearing, as proposed in this invention.

[0021] In the diagram: 1. Coupling; 2. Connecting component; 3. Workpiece fixture; 4. Mounting frame; 5. Hollow angle encoder; 6. First torque detection module; 7. Electric push rod; 8. Pointer; 9. Displacement sensor; 10. Guide rod; 11. Second torque detection module; 12. Probe; 13. Guide tube; 14. Push rod; 15. Sliding block; 16. Drive plate; 17. Arc plate; 18. Elastic rod; 19. Pressure sensor; 20. Clamping plate. Detailed Implementation

[0022] The present invention will now be further described with reference to the accompanying drawings.

[0023] Reference Figures 1-6 The present invention provides an automated device for measuring the rotational torque of a frame shaft bearing, including a servo drive unit for providing controllable rotational drive; The servo drive unit includes a servo motor, a planetary reducer connected to the output shaft of the servo motor, and a coupling 1 set at the output end of the planetary reducer. A connecting member 2 is fixedly connected to the output end of the coupling 1, and a workpiece clamp 3 is sleeved on the surface of the connecting member 2. The servo motor is an AC servo motor with high-resolution encoder feedback, which can provide precise speed and position control. The planetary reducer adopts a precision planetary gear structure, which has high rigidity and low backlash characteristics. It is used to convert the high-speed rotation of the servo motor into low-speed, high-torque output, and ensures the smoothness and adjustability of the output speed. Coupling 1 has a certain centering deviation compensation capability and is used to connect the output shaft of the planetary reducer and the connecting part 2 to reduce the impact of centering error on measurement. The servo drive unit also includes a mounting frame 4. The servo motor, planetary reducer and coupling 1 are all located on the lower surface of the mounting frame 4. The connecting piece 2 is rotatably connected to the mounting frame 4. The workpiece clamp 3 is fixedly connected to the mounting frame 4. Counterweights are provided on both sides of the lower surface of the mounting frame 4. A high-precision sensing unit is used to monitor the rotational angular position and detect micro-torque signals in real time; The high-precision sensing unit is connected to the execution control unit and works in coordination based on real-time angular position information to achieve continuous torque measurement of the workpiece around its entire circumference without dead zones. The high-precision sensing unit also includes: A hollow angle encoder 5 is non-contactly mounted on the connector 2 and is used to monitor the rotation angle of the workpiece rigidly connected inside the workpiece fixture 3 in real time. The hollow angle encoder 5 is mounted on the connector 2 to monitor the actual rotation angle in real time, effectively avoiding errors introduced by intermediate transmission links such as the reducer; The first torque detection module 6 is driven by the output end of the electric push rod 7 and can extend between the inner and outer frames of the workpiece to detect tangential micro-torque. The high-precision sensing unit includes a second torque detection module 11, which is set at the axial direction of the workpiece and is used to detect the axial load when the inner and outer frames of the workpiece are in the overlap dead zone. The first torque detection module 6 includes a pointer 8 fixedly connected to the output end of the electric push rod 7 and a sensor disposed on the surface of the pointer 8; The first torque detection module 6 serves as the main measuring unit. It is designed based on the strain measurement principle. Its force direction is tangential to the pointer 8. The pointer 8 contacts one side of the inner frame of the workpiece. The distance from the contact point to the center of the rotating shaft is fixed, forming a constant lever arm. This module directly outputs an electrical signal that is proportional to the torque. The second torque detection module 11 includes a probe 12 that is perpendicular to the pointer 8 and an axial force sensor connected to the probe 12. The sensor and the axial force sensor operate based on the strain measurement principle to ensure that the deformation is within the elastic range during the measurement process. The second torque detection module (11) includes a probe (12) set perpendicular to the pointer (8) and an axial force sensor connected to the probe (12). The sensor and the axial force sensor operate based on the strain measurement principle to ensure that the deformation is within the elastic range during the measurement process. The pointer 8 of the first torque detection module 6 is parallel to the inner frame of the workpiece to be measured, and the probe 12 of the second torque detection module 11 is perpendicular to the first torque detection module 6 and forms a perpendicular angle with the inner frame of the workpiece to be measured. The probe 12 can be set to an irregular shape to better adapt to the measurement requirements. The second torque detection module 11 serves as a dedicated dead zone compensation measurement unit. Its force direction is along the axial direction of the probe 12. The probe 12 can be designed as an irregular shape according to the workpiece structure. Under the drive of the execution control unit, it moves and fits the inner frame to better adapt to the measurement requirements. This module also directly outputs an electrical signal that is proportional to the torque. The execution control unit is used for fixing and releasing the workpiece under test and switching measurement points during the measurement process; The actuation control unit includes an electric push rod 7, a displacement sensor 9, and a guide rod 10; The electric linear actuator 7 has high repeatability and positioning accuracy. The displacement sensor 9 is used to provide real-time feedback on the position of the output end of the electric linear actuator 7 and to detect the movement distance of the pointer 8, thereby realizing closed-loop control. The electric push rod 7 is fixedly mounted on the mounting frame 4, and the output end of the electric push rod 7 is fixedly connected to the pointer 8. The displacement sensor 9 is fixedly connected to the output end of the electric push rod 7 and is set perpendicular to the pointer 8. The displacement sensor 9 is slidably sleeved on the surface of the guide rod 10, and the guide rod 10 is fixedly connected to the electric push rod 7. After the first torque detection module 6 retracts, the second torque detection module 11 is driven to extend rapidly, abutting against the inner frame of the workpiece, thus maintaining the continuity of the rotational torque measurement. The signal output terminal of displacement sensor 9 is connected to the signal acquisition and processing system via a shielded cable; The execution control unit also includes a guide tube 13 fixedly mounted on the upper surface of the mounting frame 4. Inside the guide tube 13 is a push rod 14 fixedly connected to the probe 12. The push rod 14 is slidably mounted with the guide tube 13, and the push rod 14 has the same stroke as the output end of the electric push rod 7. The guide tube 13 is used to guide the movement of the probe 12 and the push rod 14. The execution control unit also includes two sliding blocks 15 that are fixedly connected to the lower surface of the push rod 14 and the output end of the electric push rod 7, respectively. The surfaces of the sliding blocks 15 are fixedly connected to elastic elements that are fixedly connected to the mounting frame 4, and the sliding blocks 15 are slidably connected to the mounting frame 4. The surfaces of the two sliding blocks 15 are together attached to a drive plate 16 that is rotatably disposed on the surface of the mounting frame 4. Among them, the slider 15 is used to follow the movement of the pointer 8 and the probe 12; The drive plate 16 is used to drive the sliding block 15 to move. When switching between the first torque detection module 6 and the second torque detection module 11 to detect the rotational torque, the electric push rod 7 is activated, causing it to move the pointer 8. This causes the sliding block 15, which is fixedly set with the pointer 8, to slide on the mounting frame 4, pushing the drive plate 16 to rotate. This causes one side of the drive plate 16 to push the sliding block 15, which is fixedly connected to the probe 12, to move in the opposite direction, thereby driving the probe 12 and the pointer 8 to move in the opposite direction. When the detection module needs to be switched again, the system controls the output end of the electric push rod 7 to move in the opposite direction, thereby resetting the sliding block 15. Based on the elastic force of the elastic element, the sliding block 15, which is fixedly connected to the probe 12, is driven to move, so that the probe 12 slides inside the guide tube 13, taking over the first torque detection module 6 to continue to hold against the inner frame, thus achieving seamless switching of the measuring device. Initial positioning: The system is powered on and initialized. The inner frame of the workpiece is rotated to the initial angle position with human assistance and is rigidly connected to the connector 2. The first torque detection module 6 is pushed by the electric push rod 7 so that its pointer 8 contacts the side of the inner frame to achieve the purpose of measuring the rotational torque. Rotation measurement: Based on the servo motor, planetary reducer and coupling 1 driving the connecting part 2 to rotate, the outer frame of the workpiece is driven to rotate at a low speed and uniform speed. The hollow angle encoder 5 monitors the angle in real time. The inner frame remains stationary due to the obstruction of the pointer 8 on the first torque detection module 6. At this time, the rotation torque of the shaft bearing can be detected in real time and stored together with the angle data. Critical switching: When the rotation reaches the preset critical angle, the inner and outer frames enter the overlap dead zone. When the outer frame is about to contact the pointer 8, the system controls the servo motor to stop rotating and controls the electric push rod 7 to drive the pointer 8 on the first torque detection module 6 to retract. At the same time, based on the setting of the elastic element, the sliding block 15 fixed to the second torque detection module 11 slides on the mounting frame 4, driving the probe 12 on the second torque detection module 11 to extend and take over from the first torque detection module 6 to continue to hold the inner frame, realizing seamless switching of the measuring device; Dead zone measurement: After entering the dead zone, the second torque detection module 11 is activated to measure the rotational torque and store it together with the angle data. After the inner and outer frames cross the dead zone, the servo motor rotation is stopped again and the measurement device is switched. At this time, the first torque detection module 6 presses against the inner frame again to measure, completing one measurement cycle. Execution in cycles: Each time the inner and outer frame overlap dead zone is encountered during the rotation, the above measurement process is repeated to complete a full circle or multiple laps. After completion, all rotation torque and angle data are fused to generate a complete torque-angle curve. Among them, the hollow angle encoder 5 collects the workpiece rotation angle in real time in a non-contact manner, providing a unique and continuous angle label for the measurement data of the two detection modules. Whether it is the first torque detection module or the second torque detection module, the torque electrical signal output by it will be bound to the angle data at the same moment, ensuring that each measurement value can accurately correspond to a specific angle position in the 360° rotation trajectory, avoiding curve misalignment caused by angle deviation. Although the physical quantities measured by the two detection modules are different, they both output electrical signals that are proportional to the torque, and the measuring lever arm is constant, thus achieving a unified measurement dimension with the tangential torque data and eliminating the fusion barrier caused by differences in data types. Based on the angle signal from the hollow angle encoder, the non-dead zone, dead zone, and critical switching point are accurately identified, and the data from the corresponding detection module is matched according to the angle range. Non-dead zone stage: The tangential torque data from the first torque detection module 6 is bound to the corresponding angle value to form the main part of the curve; Critical switching point: The module switching is triggered by the encoder signal. At this moment, the angle at the instant of switching is used as the node to connect the end data of the first module and the initial data of the second module. Dead zone phase: The equivalent torque data from the second torque detection module 11 is used to continue binding with continuous angle values ​​to fill the data gaps in the dead zone. After crossing the dead zone: the switch is triggered again by the encoder angle signal to smoothly connect the end data of the second module with the restart data of the first module, ensuring that there is no data breakage from 0° to 360°. The boundary calibration mechanism ensures curve smoothness: In the overlapping angle range before and after the critical switching point, the measurement data of the two modules are slightly offset and corrected. Based on the torque trend of the non-dead zone and dead zone boundary, the numerical abrupt changes caused by sensor installation error, signal delay, etc. are eliminated, so that the torque data before and after the switching is continuously transitioned, and finally a complete and smooth 360° uninterrupted torque-angle curve is formed. It also includes: a limiting unit, used to detect the contact force of the second torque detection module 11 with the workpiece; The limiting unit includes arc-shaped plates 17 arranged in a ring array and slidably disposed inside the workpiece fixture 3. The outer arc surface of the arc plate 17 is symmetrically provided with elastic rods 18 fixedly connected to the workpiece fixture 3. Pressure sensors 19 are fixedly connected to one side of each of the two arc plates 17. The two pressure sensors 19 are respectively perpendicular to the probe 12 and the pointer 8. The arc-shaped plate 17 is used to closely fit the workpiece set inside the workpiece fixture 3 to limit the workpiece. Among them, the elastic rod 18 is used to control the radial movement of the arc plate 17 inside the workpiece fixture 3; Among them, pressure sensor 19 is used to detect the pressure applied by the clamping plate 20 to the arc plate 17; Both sides of the surface of the workpiece fixture 3 are provided with through slots, and the through slots are arranged opposite to the probe 12 and the pointer 8. The upper surfaces of the probe 12 and the pointer 8 are fixedly connected with a pressing plate 20. The pressing plate 20 can be attached to the pressure sensor 19 through the through slot to detect the force of the probe 12 and the pointer 8 in contact with the workpiece. The through slot is used for the pointer 8, probe 12 and clamping plate 20 to be inserted into the workpiece fixture 3 and to fit with the workpiece and pressure sensor 19. Specifically, the clamping plate 20 moves with the pointer 8 or the probe 12, so that when the pointer 8 or the probe 12 contacts the workpiece, the clamping plate 20 simultaneously contacts the pressure sensor 19, thereby detecting the pressure of the pointer 8 or the probe 12 in contact with the workpiece based on the pressure sensor 19. When the pressure is too high, the electric push rod 7 drives the first torque detection module 6 or the second torque detection module 11 to move backward, reducing the contact force between the pointer 8 or the probe 12 and the workpiece. When the pressure is too low, the electric push rod 7 drives the first torque detection module 6 or the second torque detection module 11 to move forward, increasing the contact force between the pointer 8 or the probe 12 and the workpiece. The contact pressure between pointer 8 and probe 12 and the workpiece is controlled by the pressure magnitude to avoid excessive contact force between pointer 8 and probe 12, which could lead to breakage or damage, or insufficient contact force between pointer 8 and probe 12 and the workpiece, which could result in inaccurate torque measurement. Through the implementation of the above-mentioned specific mechanical structure, sensor selection, control logic and workflow, this equipment deeply integrates high-precision sensing technology, servo motion control and innovative dead zone dynamic compensation mechanism, and successfully realizes fully automatic, blind zone-free continuous measurement of the rotational torque of the frame shaft bearing. It solves the technical problem that has long plagued this field. Moreover, the equipment has a compact structure, strong anti-interference ability, good environmental adaptability and has the potential to operate stably and reliably in industrial sites.

Claims

1. An automated device for measuring the rotational torque of a frame shaft bearing, characterized in that, Includes a servo drive unit for providing controllable rotational drive; A high-precision sensing unit is used to monitor the rotational angular position and detect micro-torque signals in real time; The execution control unit is used for fixing and releasing the workpiece under test and switching measurement points during the measurement process; The high-precision sensing unit is signal-connected to the execution control unit and works in coordination based on real-time angular position information to achieve continuous torque measurement of the workpiece without dead zones throughout its entire circumference. The high-precision sensing unit includes a second torque detection module (11), which is set at the axial direction of the workpiece and is used to detect the axial load when the inner and outer frames of the workpiece are in the overlapping dead zone. The execution control unit includes an electric push rod (7), a displacement sensor (9), and a guide rod (10). It also includes: a limiting unit for detecting the contact force of the second torque detection module (11) on the workpiece.

2. The automated device for measuring the rotational torque of a frame shaft bearing according to claim 1, characterized in that, The servo drive unit includes a servo motor, a planetary reducer connected to the output shaft of the servo motor, and a coupling (1) disposed at the output end of the planetary reducer. A connecting piece (2) is fixedly connected to the output end of the coupling (1), and a workpiece fixture (3) is sleeved on the surface of the connecting piece (2).

3. An automated device for measuring the rotational torque of a frame shaft bearing according to claim 2, characterized in that, The servo drive unit also includes a mounting frame (4), the servo motor, planetary reducer and coupling (1) are all located on the lower surface of the mounting frame (4), and the connector (2) is rotatably connected to the mounting frame (4). The workpiece fixture (3) is fixedly connected to the mounting frame (4), and counterweights are provided on both sides of the lower surface of the mounting frame (4).

4. An automated device for measuring the rotational torque of a frame shaft bearing according to claim 2, characterized in that, The high-precision sensing unit also includes: A hollow angle encoder (5) is non-contactly mounted on the connector (2) to monitor in real time the rotation angle of the workpiece rigidly connected to the workpiece fixture (3). The first torque detection module (6) is driven by the output end of the electric push rod (7) and can extend between the inner and outer frames of the workpiece to detect tangential micro-torque.

5. An automated device for measuring the rotational torque of a frame shaft bearing according to claim 4, characterized in that, The first torque detection module (6) includes a pointer (8) fixedly connected to the output end of the electric push rod (7) and a sensor disposed on the surface of the pointer (8); The second torque detection module (11) includes a probe (12) set perpendicular to the pointer (8) and an axial force sensor connected to the probe (12). The sensor and the axial force sensor operate based on the strain measurement principle to ensure that the deformation is within the elastic range during the measurement process.

6. An automated device for measuring the rotational torque of a frame shaft bearing according to claim 5, characterized in that, The electric push rod (7) is fixedly mounted on the mounting frame (4), and the output end of the electric push rod (7) is fixedly connected to the pointer (8). The displacement sensor (9) is fixedly connected to the output end of the electric push rod (7) and is set perpendicular to the pointer (8). The displacement sensor (9) is slidably sleeved on the surface of the guide rod (10), and the guide rod (10) is fixedly connected to the electric push rod (7).

7. An automated device for measuring the rotational torque of a frame shaft bearing according to claim 5, characterized in that, The execution control unit also includes a guide tube (13) fixedly disposed on the upper surface of the mounting frame (4). Inside the guide tube (13) is a push rod (14) fixedly connected to the probe (12). The push rod (14) is slidably disposed with the guide tube (13), and the push rod (14) has the same stroke as the output end of the electric push rod (7).

8. An automated device for measuring the rotational torque of a frame shaft bearing according to claim 7, characterized in that, The execution control unit also includes two sliding blocks (15) that are fixedly connected to the lower surface of the push rod (14) and the output end of the electric push rod (7), respectively. The surfaces of the sliding blocks (15) are fixedly connected to elastic elements that are fixedly connected to the mounting frame (4), and the sliding blocks (15) are slidably connected to the mounting frame (4). The surfaces of the two sliding blocks (15) are together attached to a drive plate (16) that is rotatably set on the surface of the mounting frame (4).

9. An automated device for measuring the rotational torque of a frame shaft bearing according to claim 5, characterized in that, The limiting unit includes an arc plate (17) arranged in a ring array and slidably disposed inside the workpiece fixture (3). The outer arc surface of the arc plate (17) is symmetrically provided with an elastic rod (18) fixedly connected to the workpiece fixture (3). Pressure sensors (19) are fixedly connected to one side of each of the two arc plates (17). The two pressure sensors (19) are respectively perpendicular to the probe (12) and the pointer (8).

10. An automated device for measuring the rotational torque of a frame shaft bearing according to claim 9, characterized in that, The workpiece fixture (3) has through slots on both sides of its surface, and the through slots are arranged opposite to the probe (12) and the pointer (8). The upper surfaces of the probe (12) and the pointer (8) are fixedly connected with a clamping plate (20). The clamping plate (20) can be attached to the pressure sensor (19) through the through slot to detect the force of the probe (12) and the pointer (8) against the workpiece.

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