A reverse screw pair transmission efficiency test bench

Abstract

This invention provides a test bench for testing the transmission efficiency of a reverse-type lead screw pair, comprising a main frame, a centering mechanism, and a testing system. The main frame is a vertical frame structure with a vertical testing station inside. The automatic centering mechanism includes a transition plate, an X-Y direction slide, and a tensioning device. The upper end of the transition plate is connected to the loading plate, the upper end of the X-Y direction slide is connected to the lower end of the transition plate, and the upper end of the tensioning device is connected to the lower end of the X-Y direction slide. This invention adopts a vertical frame layout, with the tested reverse-type lead screw pair, drive spindle, and loading lead screw all installed vertically. The movement direction of the lead screw and nut is parallel to the direction of gravity, and the self-weight of the nut and lead screw is borne by axial support, preventing radial deflection. This eliminates the unavoidable gravitational additional bending moment inherent in horizontal structures, making the measured transmission efficiency closer to the true theoretical value of the lead screw pair.

Description

Technical Field

[0001] This invention relates to the field of testing technology, and in particular to a test bench for testing the efficiency of a reverse-type lead screw pair transmission. Background Technology

[0002] In the field of mechanical transmission, lead screw pairs are widely used in high-end equipment such as CNC machine tools, industrial robots, and aerospace due to their significant advantages of high precision, high efficiency, and high rigidity. Traditional standard lead screw pairs typically employ a motion pattern of screw rotation and nut axial movement, while reverse lead screw pairs employ a motion pattern of nut rotation and screw axial movement. Due to this unique motion characteristic, reverse lead screw pairs offer greater structural flexibility and application value in specific application scenarios such as robot joints and military equipment, and often utilize a long nut structure to accommodate long stroke requirements.

[0003] Currently, the transmission efficiency of the reverse lead screw pair is a key indicator for evaluating its performance, directly related to its energy loss, heat generation, and control accuracy. Accurate measurement of this indicator is crucial for evaluating product performance and guiding design optimization. In the existing technology, the test of the reverse lead screw pair mostly adopts a horizontal layout. However, the horizontal layout has obvious limitations: (1) Since the reverse lead screw pair often adopts a long nut structure, in the horizontal installation state, the weight of the long nut and the lead screw can easily cause bending deformation, generating additional bending moment, which in turn increases frictional resistance, resulting in distortion of the transmission efficiency measurement results and failing to reflect the true performance of the lead screw pair; (2) The torque sensor of the existing test device is often located before the support bearing, resulting in the measured torque including the frictional loss of the support bearing, which seriously affects the calculation accuracy of the input power; (3) Inaccurate axial force measurement and additional radial resistance introduced by poor installation alignment further reduce the reliability and repeatability of the test results. Summary of the Invention

[0004] The technical problem to be solved by this invention is to solve the problems of low measurement accuracy and poor repeatability caused by gravity-induced bending moment and poor installation alignment of existing horizontal test benches.

[0005] To solve the above technical problems, the present invention provides the following technical solution: a reverse-type lead screw pair transmission efficiency test bench, including a bench body, a loading system and a test system, wherein the loading system includes a second servo motor, a synchronous belt transmission mechanism, two loading lead screw pairs, a loading plate and an automatic centering mechanism;

[0006] The main body of the test bench is a vertical frame structure, with vertical testing stations inside.

[0007] The output shaft of the second servo motor is synchronously connected to the upper ends of the two loading screw pairs through a synchronous belt transmission mechanism. The two sides of the loading plate are fixedly connected to the nuts of the two loading screw pairs respectively, and the two ends of the loading plate are slidably engaged with the vertical guide rails set on the main body of the frame.

[0008] The automatic centering mechanism includes a transition plate, an XY direction slide, and a tensioning device. The upper end of the transition plate is connected to the loading plate, the upper end of the XY direction slide is connected to the lower end of the transition plate, and the upper end of the tensioning device is connected to the lower end of the XY direction slide. The tensioning device is used to clamp and fix the tail end of the tested reverse-type lead screw pair.

[0009] The testing system includes a tension / compression sensor and a linear encoder. The tension / compression sensor is located between the loading plate and the adapter plate to measure the axial load force. The scale of the linear encoder is located on the side plate of the main body of the test bench, and its reading head is located on the loading plate to measure the displacement velocity of the loading plate.

[0010] As a preferred embodiment of the reverse-type lead screw transmission efficiency test bench of the present invention, it further includes a drive system, which is disposed at the lower part of the main body of the test bench; the drive system includes a first servo motor, a double diaphragm coupling, a main shaft, a flange torque sensor, a turntable and a slip ring, the output shaft of the first servo motor is connected to the main shaft through the double diaphragm coupling, the main shaft is vertically mounted on the main body of the test bench through a double-row angular contact bearing assembly, the input end of the flange torque sensor is connected to the upper end of the main shaft, the output end of the flange torque sensor is connected to the turntable, the turntable has a hollow structure and is provided with positioning fixtures inside, the slip ring is sleeved on the main shaft, the rotor of the slip ring is connected to the cable of the flange torque sensor, and the stator of the slip ring is fixed to the main body of the test bench;

[0011] The double diaphragm coupling is used to compensate for installation errors and eliminate backlash.

[0012] The double-row angular contact bearing assembly is used to withstand the axial and radial loads on the spindle;

[0013] The flange-type torque sensor has axial load bearing capacity, and the flange-type torque sensor is arranged between the double-row angular contact bearing assembly and the turntable.

[0014] The turntable is used to fix the nut of the tested reverse-type lead screw pair and restrict its axial movement.

[0015] As a preferred embodiment of the reverse screw pair transmission efficiency test bench of the present invention, the test system further includes a data acquisition controller, which is electrically connected to the first servo motor, the second servo motor, the flange torque sensor, the tension and compression sensor and the grating ruler respectively. The data acquisition controller is used to calculate and output the transmission efficiency of the reverse screw pair under test.

[0016] As a preferred embodiment of the reverse screw pair transmission efficiency test bench of the present invention, the data acquisition controller calculates the input power based on the input torque collected by the flange torque sensor and the speed of the first servo motor, calculates the output power based on the total load force collected by the tension and compression sensors and the moving speed of the reverse screw pair under test collected by the grating ruler, and calculates the ratio of the output power to the input power as the transmission efficiency.

[0017] As a preferred embodiment of the reverse screw pair transmission efficiency test bench of the present invention, the synchronous belt transmission mechanism includes a driving small pulley, two driven large pulleys and a tension pulley. The driving small pulley is installed on the output shaft of the second servo motor, the two driven large pulleys are respectively installed on the upper end of the screws of the two loading screw pairs, and the tension pulley is set on the slack side of the synchronous belt.

[0018] The tensioning wheel is used to adjust the preload of the timing belt.

[0019] As a preferred embodiment of the reverse screw pair transmission efficiency test bench of the present invention, wherein: the loading screw pair is a ball screw pair, the upper end of the screw of the reverse screw pair under test is fixedly connected to the top of the main body of the test bench through a double row angular contact bearing assembly to form a fixed end, and the lower end of the screw of the reverse screw pair under test is connected to the bottom of the main body of the test bench through a deep groove ball bearing to form a floating end.

[0020] As a preferred embodiment of the reverse screw pair transmission efficiency test bench of the present invention, three tension and compression sensors are provided, and the three tension and compression sensors are equidistantly arranged between the loading plate and the adapter plate along the length direction of the loading plate.

[0021] As a preferred embodiment of the reverse screw pair transmission efficiency test bench of the present invention, the positioning fixture in the turntable includes an axial positioning step and a circumferential keyway. The turntable is used to fix the nut of the reverse screw pair under test so that it can only rotate synchronously with the turntable.

[0022] As a preferred embodiment of the reverse-type screw pair transmission efficiency test bench of the present invention, the XY direction slide is composed of two sets of cross-roller guide slides. The XY direction slide is used to provide small movements in the mutually perpendicular X and Y directions to compensate for the alignment deviation between the drive system and the loading system.

[0023] The beneficial effects of the present invention are as follows: (1) The present invention adopts a vertical frame layout. The tested reverse screw pair, drive spindle, and loading screw are all installed vertically. The movement direction of the screw and nut is parallel to the direction of gravity. The self-weight of the nut and screw is borne by axial support, and there will be no radial deflection. This eliminates the inevitable gravity-induced bending moment in the horizontal structure from the root, making the measured transmission efficiency closer to the true theoretical value of the screw pair. (2) The present invention innovatively designs an automatic centering mechanism composed of an XY direction slide and a tensioning device at the load end. After the tensioning device clamps the tail end of the screw, the XY direction slide can automatically compensate for the positional deviation between the drive end (turntable) and the load end (tensioning device) in the horizontal plane. This design effectively reduces the stringent requirements for the frame processing accuracy and manual assembly accuracy, reduces the installation accuracy requirements, realizes automatic centering, avoids the additional radial resistance introduced by poor installation centering, and ensures the measurement accuracy. The authenticity and repeatability of the results; (3) The present invention arranges the flange-type torque sensor with axial load bearing capacity after the main shaft support bearing (double row angular contact bearing group) and before the turntable; This structural layout makes the torque measured by the torque sensor only the net torque required to drive the nut to rotate, eliminating the interference of the support bearing's own friction loss on the measurement results, thereby significantly improving the measurement accuracy of input power and providing high-precision basic data for the calculation of final transmission efficiency; (4) The loading plate is driven by the synchronous loading screw on both sides, and the total load force is directly measured by three evenly distributed tension and compression sensors, ensuring the uniformity of the loading force and the directness of the measurement value; At the same time, the grating ruler directly measures the moving speed of the loading plate (i.e. the screw), and it is on the same structural component as the load force measurement, improving the accuracy of the loading force measurement and the synchronization of motion parameters, and ensuring the synchronization and accuracy of force and speed parameters in the output power calculation. Attached Figure Description

[0024] Figure 1 This is a structural diagram of the test bench in the disclosed embodiment of the present invention.

[0025] Figure 2 This is a schematic diagram of the overall structure of the test bench in the disclosed embodiment of the present invention.

[0026] Figure 3 This is a partial structural diagram of the drive system portion in an embodiment of the present invention.

[0027] Figure 4This is a partial structural diagram of the loading system and automatic centering mechanism in an embodiment of the present invention.

[0028] Figure 5 This is a top view of the synchronous belt drive mechanism in an embodiment of the present invention.

[0029] Figure 6 This is a schematic diagram of the test system connection in an embodiment of the present invention.

[0030] Reference numerals: 1. Main body of the test bench; 101. Vertical guide rail; 201. First servo motor; 202. Double diaphragm coupling; 203. Main shaft; 204. Double row angular contact bearing assembly; 205. Flange-type torque sensor; 206. Turntable; 207. Slip ring; 301. Loading screw pair; 302. Second servo motor; 3031. Driving small pulley; 3032. Driven large pulley; 3033. Tensioning wheel; 304. Loading plate; 3051. Adapter plate; 3052. XY direction slide table; 3053. Tensioning device; 401. Nut; 402. Screw; 5. Test system; 501. Tension / compression sensor; 502. Grating ruler; 503. Data acquisition controller. Detailed Implementation

[0031] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0032] Reference Figures 1 to 6 This embodiment provides a test bench for testing the transmission efficiency of a reverse-type lead screw pair, including a main frame 1, an automatic centering mechanism, and a testing system 5. The main frame 1 is a vertical frame structure with a vertical testing station inside. In this embodiment, the main frame 1 is integrally cast from high-strength cast iron or welded from structural steel to form a vertical frame structure. It has a mounting base at the bottom, a crossbeam at the top, and an open testing space in the middle. Precision vertical guide rails 101 are symmetrically fixed to the inner walls of the left and right sides of the main frame 1 to guide the loading plate 304. The entire main frame 1 has sufficient rigidity and stability to ensure the relative positional accuracy of each component during testing. The vertical frame structure of the main frame 1 ensures that the reverse-type lead screw pair under test is installed in a vertical orientation. This layout ensures that the movement direction of the lead screw 402 and nut 401 is parallel to the direction of gravity. The self-weight of the nut 401 and lead screw 402 is borne by axial support, and radial deflection will not occur. This eliminates the unavoidable gravitational additional bending moment in the horizontal structure from the root, making the measured transmission efficiency closer to the true theoretical value of the tested reverse lead screw pair.

[0033] Reference Figure 4The automatic centering mechanism includes a transition plate 3051, an XY direction slide 3052, and a tensioning device 3053. The upper end of the transition plate 3051 is connected to the loading plate 304, the upper end of the XY direction slide 3052 is connected to the lower end of the transition plate 3051, and the upper end of the tensioning device 3053 is connected to the lower end of the XY direction slide 3052. The tensioning device 3053 is used to clamp and fix the tail end of the lead screw 402 of the tested reverse lead screw pair.

[0034] In this embodiment, the automatic centering mechanism includes, from top to bottom, an adapter plate 3051, an XY direction slide 3052, and a tensioning device 3053. The upper surface of the adapter plate 3051 is connected to the lower surface of the loading plate 304 by bolts, and three tension / compression sensors 501 are installed between them. The lower surface of the adapter plate 3051 is fixed to the top surface of the XY direction slide 3052. The XY direction slide 3052 adopts a cross-roller guide structure, which can provide high-precision micro-movement in the X and Y directions. The upper end face of the tensioning device 3053 is fixed to the bottom surface of the XY direction slide 3052. The tensioning device 3053 is a tapered sleeve locking structure, and its central hole is used to pass through the tail end journal of the lead screw 402 of the measured reverse lead screw pair. By tightening the circumferential bolts of the tensioning device 3053, the inner hole of the tapered sleeve shrinks uniformly, firmly gripping the journal of the lead screw 402, thereby restricting the circumferential rotational freedom of the lead screw 402 and making it only able to move axially.

[0035] Reference Figure 4 and Figure 6 The testing system 5 includes a tension / compression sensor 501 and a grating ruler 502. The tension / compression sensor 501 is located between the loading plate 304 and the adapter plate 3051 and is used to measure the axial load force. The scale of the grating ruler 502 is located on the side plate of the main body 1 of the test bench, and its reading head is located on the loading plate 304 and is used to measure the displacement speed of the loading plate 304.

[0036] In this embodiment, three high-precision tension / compression sensors 501 are equidistantly arranged between the loading plate 304 and the adapter plate 3051 along the length of the loading plate 304. Each sensor is S-shaped or spoke-shaped, with its upper and lower ends connected to the loading plate 304 and the adapter plate 3051 respectively via threads. The signals from the three sensors are processed by a summing amplifier and then input to the data acquisition controller, representing the total axial load F applied by the loading system. The uniform distribution of the three tension / compression sensors 501 eliminates the influence of off-center loading and ensures the accuracy of the measured values.

[0037] The scale of the grating ruler 502 is affixed to the left or right outer wall of the main body 1 of the test bench, and its reading head is mounted on the loading plate 304 via a bracket. When the loading plate 304 moves, the reading head reads the scale on the ruler and outputs a digital pulse signal proportional to the displacement. The data acquisition controller calculates the displacement of the loading plate 304, and then differentiates it to obtain the moving speed v of the lead screw 402. The input power is calculated based on the input torque collected by the flange torque sensor 205 and the rotational speed of the first servo motor 201. The output power is calculated based on the total load force collected by the tension and compression sensor 501 and the moving speed of the measured reverse lead screw pair collected by the grating ruler 502. The ratio of the output power to the input power is then calculated as the transmission efficiency.

[0038] The reverse-type lead screw transmission efficiency test bench of this embodiment also includes a drive system, which is located at the lower part of the main body 1 of the test bench. The drive system includes a first servo motor 201, a double diaphragm coupling 202, a main shaft 203, a flange torque sensor 205, a turntable 206, and a slip ring 207. The output shaft of the first servo motor 201 is connected to the main shaft 203 through the double diaphragm coupling 202. The main shaft 203 is vertically mounted on the main body 1 of the test bench through a double-row angular contact bearing assembly 204. The input end of the flange torque sensor 205 is connected to the upper end of the main shaft 203, and the output end of the flange torque sensor 205 is connected to the turntable 206. The turntable 206 has a hollow structure and is equipped with positioning fixtures inside. The slip ring 207 is sleeved on the main shaft 203. The rotor of the slip ring 207 is connected to the cable of the flange torque sensor 205, and the stator of the slip ring 207 is fixed on the main body 1 of the test bench. The double diaphragm coupling 202 is used to compensate for installation errors and eliminate backlash; the double-row angular contact bearing assembly 204 is used to bear the axial and radial loads on the main shaft 203; the flange-type torque sensor 205 has axial load-bearing capacity, and the flange-type torque sensor 205 is arranged between the double-row angular contact bearing assembly 204 and the turntable 206, so that the torque value measured by the flange-type torque sensor 205 does not include the friction loss of the double-row angular contact bearing assembly 204. The turntable 206 is used to fix the nut 401 of the measured reverse-type lead screw pair and restrict its axial movement.

[0039] In this embodiment, the drive system is mounted on the bottom base of the main frame 1, adopting a vertical upward power output layout. The first servo motor 201 is vertically fixed to the bottom of the base via a motor mount, with its output shaft facing upward. The output shaft of the first servo motor 201 is connected to the lower end of the main shaft 203 via a high-precision double diaphragm coupling 202. The double diaphragm coupling 202 can compensate for minor coaxiality deviations between the motor shaft of the first servo motor 201 and the main shaft 203, and eliminate backlash, ensuring smooth power transmission. The inner ring of the double-row angular contact bearing assembly 204 mates with the main shaft 203, and the outer ring mates with the bearing housing. This mounting method provides a large span, enabling it to withstand large axial and radial loads simultaneously, ensuring the rotational accuracy of the main shaft 203 under high-speed rotation and axial reaction force.

[0040] A flange is machined onto the upper end of the spindle 203, which is bolted to the input flange of the flange-type torque sensor 205. The internal structure of this flange-type torque sensor 205 allows axial loads to pass through without affecting torque measurement, thus possessing axial load-bearing capacity. The sensor is positioned above the double-row angular contact bearing assembly 204, therefore the measured torque value is only the net torque required to drive the subsequent load, excluding bearing friction losses, thereby ensuring the accuracy of the input torque measurement.

[0041] The output flange of the flange-type torque sensor 205 is fixedly connected to the flange of the turntable 206 by bolts. The turntable 206 is a hollow disc made of high-strength steel, and its central hole is used to accommodate the nut 401 of the measured reverse-type lead screw pair. The inner wall of the turntable 206 is designed with an axial positioning step and a circumferential keyway, which can accurately and firmly fix the nut 401 inside the turntable 206, so that it can only rotate synchronously with the turntable 206 and cannot produce axial movement.

[0042] A slip ring 207 is mounted on the main shaft 203. The rotor portion of the slip ring 207 rotates together with the main shaft 203, and its lead wire is connected to the signal cable of the flange-type torque sensor 205. The stator portion of the slip ring 207 is fixed to the main body 1 of the test bench by a bracket, and its lead wire is connected to the data acquisition controller 503. Through the slip ring 207, stable and continuous transmission of sensor signals between the rotating parts and the stationary equipment is achieved.

[0043] The test bench also includes a loading system, which is set on both sides of the main body 1 of the test bench. The loading system includes a second servo motor 302, a synchronous belt drive mechanism, two loading screw pairs 301 and a loading plate 304. The output shaft of the second servo motor 302 is synchronously connected to the upper end of the two loading screw pairs 301 through the synchronous belt drive mechanism. The two sides of the loading plate 304 are fixedly connected to the nuts of the two loading screw pairs 301 respectively, and the two ends of the loading plate 304 are slidably engaged with the vertical guide rail 101 set on the main body 1 of the test bench.

[0044] In this embodiment, the loading screw pair 301 is a high-precision ball screw pair. The upper end of the screw is fixedly connected to the top crossbeam of the main body 1 of the test bench through a set of double-row angular contact bearings 204, forming a fixed end to bear axial load and ensure positioning accuracy. The lower end of the screw 402 is connected to the bottom crossbeam of the main body 1 of the test bench through a deep groove ball bearing, forming a floating end, allowing the screw 402 to extend freely downward during thermal expansion, avoiding additional stress.

[0045] The second servo motor 302 is mounted on one side of the top crossbeam of the main body 1 of the test bench. The synchronous belt drive mechanism consists of a driving small pulley 3031, two driven large pulleys 3032, and a tension pulley 3033. The driving small pulley 3031 is mounted on the output shaft of the second servo motor 302. The two driven large pulleys 3032 are respectively fixed to the upper end of the lead screws of the two side loading lead screw pairs 301 by keys. A high-strength synchronous belt passes sequentially around the driving small pulley 3031, one driven large pulley 3032, the tension pulley 3033, and the other driven large pulley 3032, forming a closed loop. The tension pulley 3033 is mounted on an adjustable slide. By adjusting the position of the slide, the tension of the synchronous belt can be changed to ensure the accuracy and synchronization of the transmission and avoid slippage.

[0046] The loading plate 304 is a rectangular thick steel plate, with its two ends slidingly engaged with the vertical guide rail 101 on the main body of the frame via linear guide sliders. The two sides of the loading plate 304 are fixedly connected to the nuts of two loading lead screw pairs 301 via nut seats. When the second servo motor 302 drives the two lead screws to rotate synchronously, the two nuts cause the loading plate 304 to move smoothly up and down along the vertical guide rail 101.

[0047] The test system 5 also includes a data acquisition controller 503, which is electrically connected to the first servo motor 201, the second servo motor 302, the flange torque sensor 205, the tension and compression sensor 501, and the grating ruler 502. The data acquisition controller 503 is used to calculate and output the transmission efficiency of the tested reverse lead screw pair.

[0048] The data acquisition controller 503 calculates the input power based on the input torque collected by the flange torque sensor 205 and the speed of the first servo motor 201, calculates the output power based on the total load force collected by the tension and compression sensor 501 and the moving speed of the measured reverse screw pair collected by the grating ruler 502, and calculates the ratio of the output power to the input power as the transmission efficiency.

[0049] The data acquisition controller 503 employs a high-performance programmable logic controller (PLC) or industrial computer, and integrates an analog input module, a high-speed counter module, and a motion control module. The data acquisition controller 503 connects to the drivers of the first servo motor 201 and the second servo motor 302 via the motion control module to achieve the setting and control of speed and torque. The torque signal T from the flange-type torque sensor 205 is acquired through the analog input module. in The system collects force signals F from three tension and compression sensors 501. Displacement pulse signals from the grating ruler 502 are acquired via a high-speed counter module to calculate velocity v. Simultaneously, the rotational speed n of the first servo motor 201 is read via a communication protocol. in .

[0050] The data acquisition controller 503 has an embedded data processing program that performs the following calculations in real time:

[0051] Input power P in =(T in ×n in ) / 9550;

[0052] Output power P out =F×v;

[0053] Transmission efficiency η=(P out / P in )×100%;

[0054] Where, n in For the driver of the first servo motor 201, the speed feedback is P in The unit is kW, T in The unit is Nm, n in The unit is rpm, P out The unit is kW, F is kN, and v is m / s.

[0055] Test results are displayed in real time on the human-machine interface and automatically stored in the database, supporting historical data query and curve plotting.

[0056] The XY direction slide 3052 consists of two sets of cross-roller guide slides. It provides minute movements in the mutually perpendicular X and Y directions to compensate for alignment deviations between the drive system and the loading system. By eliminating additional bending moments through a vertical structure, reducing installation accuracy requirements through an automatic alignment mechanism, and improving input power accuracy through optimized torque measurement positions, it achieves high-precision and high-reliability testing of the transmission efficiency of the reverse-type lead screw pair under test.

[0057] The method of using the reverse lead screw pair transmission efficiency test bench described in this embodiment includes: Step 1, installation and alignment: The nut 401 of the reverse lead screw pair to be tested is fixed in the turntable 206 using a positioning fixture; the tail end of the lead screw 402 is passed through the tensioning device 3053, and the XY direction slide 3052 is adjusted so that the axis of the lead screw 402 naturally coincides with the axis of the nut 401, and then the tensioning device 3053 is locked; this step eliminates installation eccentricity through the automatic alignment mechanism. Step 2, parameter setting and start: The target speed of the first servo motor 201 (i.e., the input speed of the reverse lead screw pair to be tested) and the target torque or speed of the second servo motor 302 (i.e., the set load force) are set on the data acquisition controller 503, and the test program is started. Step 3, Loading and Driving: The first servo motor 201 starts, driving the turntable 206 and nut 401 to rotate via the spindle 203 and flange torque sensor 205; according to the screw drive principle, the screw 402 tends to move axially; simultaneously, the second servo motor 302 starts, driving the two loading screw pairs 301 to rotate synchronously via the synchronous belt drive mechanism, causing the loading plate 304 to move downwards, and applying an axial load force opposite to the direction of movement to the screw 402 through the automatic centering mechanism. Step 4, Data Acquisition and Calculation: Throughout the entire movement process, the flange torque sensor 205 collects the input torque T in real time. in The driver of the first servo motor 201 provides feedback on the rotational speed n. in Three tension and compression sensors 501 collect the total load force F, and the grating ruler 502 collects the lead screw movement speed v. The data acquisition controller synchronously collects all signals and calculates the input power, output power, and transmission efficiency in real time according to the aforementioned formula. Step 5, multi-condition testing: By changing the speed of the first servo motor 201 and the loading force of the second servo motor 302, the transmission efficiency spectrum of the tested reverse lead screw pair under different speeds and load conditions can be measured, providing comprehensive data support for product performance evaluation and optimization design.

Claims

1. A reverse screw pair transmission efficiency test bench, characterized in that, The system includes a main body (1), a loading system and a testing system (5). The loading system includes a second servo motor (302), a synchronous belt drive mechanism, two loading screw pairs (301), a loading plate (304), and an automatic centering mechanism. The main body of the test bench (1) is a vertical frame structure, and a vertical test station is provided inside it; The output shaft of the second servo motor (302) is synchronously connected to the upper end of the two loading screw pairs (301) through a synchronous belt transmission mechanism. The two sides of the loading plate (304) are fixedly connected to the nuts of the two loading screw pairs (301) respectively, and the two ends of the loading plate (304) are slidably engaged with the vertical guide rail (101) set on the main body of the frame (1). The automatic centering mechanism includes a transition plate (3051), an XY direction slide (3052), and a tensioning device (3053). The upper end of the transition plate (3051) is connected to the loading plate (304), the upper end of the XY direction slide (3052) is connected to the lower end of the transition plate (3051), and the upper end of the tensioning device (3053) is connected to the lower end of the XY direction slide (3052). The tensioning device (3053) is used to clamp and fix the tail end of the lead screw (402) of the tested reverse lead screw pair. The test system (5) includes a tension and compression sensor (501) and a grating ruler (502); the tension and compression sensor (501) is set between the loading plate (304) and the adapter plate (3051) for measuring the axial load force; the scale of the grating ruler (502) is set on the side plate of the main body of the test bench (1), and its reading head is set on the loading plate (304) for measuring the displacement speed of the loading plate (304).

2. The reverse screw pair transmission efficiency test bench according to claim 1, characterized in that, It also includes a drive system, which is located at the lower part of the main body of the test bench (1); the drive system includes a first servo motor (201), a double diaphragm coupling (202), a spindle (203), a flange torque sensor (205), a turntable (206) and a slip ring (207). The output shaft of the first servo motor (201) is connected to the main shaft (203) through a double diaphragm coupling (202). The main shaft (203) is vertically mounted on the main body of the test bench (1) through a double row angular contact bearing assembly (204). The input end of the flange torque sensor (205) is connected to the upper end of the main shaft (203). The output end of the flange torque sensor (205) is connected to the turntable (206). The turntable (206) has a hollow structure and is equipped with positioning fixtures inside. The slip ring (207) is sleeved on the main shaft (203). The rotor of the slip ring (207) is connected to the cable of the flange torque sensor (205). The stator of the slip ring (207) is fixed to the main body of the test bench (1). The double diaphragm coupling (202) is used to compensate for installation errors and eliminate backlash; The double-row angular contact bearing assembly (204) is used to bear the axial and radial loads on the spindle (203); The flange-type torque sensor (205) has axial load bearing capacity, and the flange-type torque sensor (205) is arranged between the double-row angular contact bearing assembly (204) and the turntable (206); The turntable (206) is used to fix the nut (401) of the tested reverse lead screw pair and restrict its axial movement.

3. The reverse screw pair transmission efficiency test bench according to claim 1, characterized in that, The test system (5) also includes a data acquisition controller (503), which is electrically connected to the first servo motor (201), the second servo motor (302), the flange torque sensor (205), the tension and compression sensor (501), and the grating ruler (502). The data acquisition controller (503) is used to calculate and output the transmission efficiency of the tested reverse screw pair.

4. The reverse screw pair transmission efficiency test test rig of claim 3, wherein, The data acquisition controller (503) calculates the input power based on the input torque collected by the flange torque sensor (205) and the rotational speed of the first servo motor (201), calculates the output power based on the total load force collected by the tension and compression sensor (501) and the moving speed of the measured reverse screw pair collected by the grating ruler (502), and calculates the ratio of the output power to the input power as the transmission efficiency.

5. The reverse screw pair transmission efficiency test bench according to claim 1, characterized in that, The synchronous belt drive mechanism includes a driving small pulley (3031), two driven large pulleys (3032), and a tensioning pulley (3033). The driving small pulley (3031) is mounted on the output shaft of the second servo motor (302). The two driven large pulleys (3032) are respectively mounted on the upper end of the screws of the two loading screw pairs (301). The tensioning pulley (3033) is located on the slack side of the synchronous belt. The tensioning pulley (3033) is used to adjust the preload of the synchronous belt.

6. The reverse screw pair transmission efficiency test bench according to claim 2, characterized in that, The loading screw pair (301) is a ball screw pair. The upper end of the screw (402) of the tested reverse screw pair is fixedly connected to the top of the test bench body (1) through a double-row angular contact bearing group (204) to form a fixed end. The lower end of the screw (402) of the tested reverse screw pair is connected to the bottom of the test bench body (1) through a deep groove ball bearing to form a floating end.

7. The reverse screw pair transmission efficiency test bench according to claim 1, characterized in that, Three tension / compression sensors (501) are provided, and the three tension / compression sensors (501) are arranged at equal intervals between the loading plate (304) and the adapter plate (3051) along the length direction of the loading plate (304).

8. The reverse screw pair transmission efficiency test bench according to claim 2, characterized in that, The positioning fixture inside the turntable (206) includes an axial positioning step and a circumferential keyway. The turntable (206) is used to fix the nut (401) of the tested reverse screw pair so that it can only rotate synchronously with the turntable (206).

9. The reverse screw pair transmission efficiency test bench according to claim 1, characterized in that, The XY direction slide (3052) consists of two sets of cross-roller guide slides. The XY direction slide (3052) is used to provide small movements in the X and Y directions that are perpendicular to each other to compensate for the alignment deviation between the drive system and the loading system.

Images