Precision retentivity loading test device for disassembly-free ball screw pair

Abstract

The invention discloses a disassembly-free ball screw pair precision retentivity loading test device. The device comprises a lathe bed part, a driving mechanism, an integrated headstock, a movable workbench, two loading mechanisms, a stroke error measuring mechanism, a friction torque measuring mechanism, a contact rigidity measuring mechanism and a temperature measuring mechanism. Wherein the stroke error measuring mechanism is arranged on the lathe bed part; the friction torque measuring mechanism is arranged on the movable workbench, and the contact rigidity measuring mechanism is also arranged on the movable workbench; a zero position sensor and two mechanical limiting sensors are arranged on the side of the movable workbench. Therefore, the device integrates a loading function and intelligent online measurement, synchronous monitoring of multiple key parameters can be completed without disassembling the lead screw pair, damage to the shaft end of the lead screw and assembly errors caused in the assembling and disassembling process are effectively avoided, the test efficiency and the test data precision are remarkably improved, and the device is suitable for precision retentivity evaluation of the high-precision ball screw pair.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric vehicle component testing, and in particular to a disassembly-free ball screw pair precision retention loading test device. BACKGROUND

[0002] Ball screws convert the rotary motion of auxiliary motors into linear motion and serve as precise transmission components of electric power steering systems. Ball screws play a key role in realizing vehicle parking assistance, lane departure warning, and different levels of automatic driving functions, and can bring excellent steering control, safety, and comfort to vehicles.

[0003] Ball screw pairs are core transmission components that convert rotary motion into linear motion with high precision. They have become indispensable functional components due to their excellent transmission efficiency, load capacity, and positioning accuracy. The precision retention during their long-term operation directly determines the machining quality, operational stability, and service life of the equipment. Therefore, performance monitoring and loading tests of ball screw pairs throughout their life cycle are key links to ensure the reliability of high-end equipment.

[0004] As industrial manufacturing develops towards high precision and high reliability, the industry has higher requirements for performance evaluation of ball screw pairs. Not only are performance parameters under a single working condition needed, but also precision retention monitoring in multiple dimensions and throughout the entire process is required. However, existing ball screw pair test devices have the following limitations: first, they have single functions, and most devices can only perform life tests or single performance parameter detection, making it difficult to fully reflect the comprehensive performance of the screw pair; second, the test process requires frequent disassembly of the screw pair to replace the test platform or adjust the measurement position, which increases the complexity of operation, reduces the test efficiency, and easily causes damage to the screw shaft end, accumulates assembly errors, and seriously affects the accuracy and repeatability of measurement data; third, the measurement environment adaptability is poor, and the long grating used in traditional stroke error measurement is easily contaminated by oil and debris in the working area, and temperature measurement relies on manual operation, which is low in automation and difficult to ensure measurement accuracy; fourth, there is a lack of compensation mechanism for factors such as screw rotation interference and reference tilt during the test process, resulting in large measurement errors of key parameters such as contact stiffness, which makes it difficult to meet the performance evaluation needs of high-precision screw pairs. SUMMARY

[0005] The present application aims to at least partially solve one of the technical problems in the related art.

[0006] To this end, one object of the present application is to provide a disassembly-free ball screw pair precision retention loading test device, which not only has the loading capacity to simulate the actual working conditions of the screw pair, but also integrates an integrated intelligent detection function, without the need for repeated disassembly and reassembly of the screw pair, effectively avoiding the loss of measurement accuracy and potential damage to the shaft end caused by disassembly and assembly operations, and significantly improving the stability of the test and the reliability of the results.

[0007] To achieve the above object, the first aspect of the present application provides a disassembly-free ball screw pair precision retention loading test device, comprising a bed part, a driving mechanism, an integrated headstock, a moving workbench, two loading mechanisms, a stroke error measuring mechanism, a friction torque measuring mechanism, a contact stiffness measuring mechanism and a temperature measuring mechanism; wherein the stroke error measuring mechanism is arranged on the bed part; the friction torque measuring mechanism is arranged on the moving workbench, and the contact stiffness measuring mechanism is also arranged on the moving workbench; the side of the moving workbench is provided with a zero sensor and two mechanical limit sensors; the driving mechanism and the two loading mechanisms are arranged on the bed part, the integrated headstock is fixedly arranged at one end of the bed part, and the moving workbench is arranged in the middle of the bed part; three through holes are formed in the moving workbench; the driving mechanism penetrates the middle part of the integrated headstock, and the two loading mechanisms penetrate the two sides of the integrated headstock respectively; the driving mechanism comprises a driving motor, a measured screw pair, a tailstock, a screw end coupling, a motor end coupling and a first extension rod;

[0008] Wherein, the driving motor is arranged at one end of the bed part, and the tailstock is arranged at the other end of the bed part; one end of the motor end coupling connected with the output shaft of the driving motor is arranged inside the integrated headstock, the other end of the motor end coupling is connected with the first extension rod, and the other end of the first extension rod is connected with the screw end coupling; the measured screw pair is installed between the integrated headstock and the tailstock, penetrates the through hole in the middle of the moving workbench, one end of the measured screw pair is connected with the screw end coupling, and the other end of the measured screw pair is connected with the tailstock; the temperature measuring mechanism is arranged on the driving mechanism.

[0009] The precision retention loading test device of the ball screw pair without disassembly provided by the embodiment of the application not only has the loading capacity of simulating the actual working condition of the screw pair, but also integrates an integrated intelligent detection function. Without repeatedly disassembling and reassembling the screw pair, the precision loss caused by disassembly and reassembly and the potential damage to the shaft end are effectively avoided, and the stability of the test and the reliability of the result are significantly improved. Not only the test efficiency is greatly improved, but also the high precision, repeatability and consistency of the data are ensured, which provides strong support for the performance evaluation and reliability research of the screw pair.

[0010] In addition, the precision retention loading test device of the ball screw pair without disassembly provided by the embodiment of the application can have the following additional technical features:

[0011] In an embodiment of the application, the loading mechanism includes loading motors, thrust combined bearings, loading screws, deep groove ball bearings, loading nuts, loading tension and pressure sensors, second extension rods, first couplings and second couplings. Two loading motors are respectively arranged on the two sides of the driving motor. The output of each driving motor passes through the integrated headstock and is connected with one end of the second coupling arranged inside the integrated headstock. The other end of the second coupling is connected with one end of the second extension rod. The other end of the second extension rod is connected with one end of the first coupling. The other end of the first coupling is connected with one end of the thrust combined bearing. One end of the thrust combined bearing is connected with one end of the loading screw. The other ends of the two loading screws pass through the through holes on the two sides of the moving workbench and are connected with deep groove ball bearings. The deep groove ball bearings are arranged on the loading rear seat. The loading nuts are arranged on the loading screws and are connected with the loading tension and pressure sensors.

[0012] The loading nuts are arranged on the loading screws and are connected with the loading tension and pressure sensors.

[0013] In an embodiment of the application, the bed body component includes a bed body, linear guide pairs, limiting supports and locking guides. The locking guide is arranged on the bed body. The limiting support is arranged on the locking guide, and the position of the limiting support corresponds to the positions of the zero position sensor and the mechanical sensor. The bed body is provided with a T-shaped sliding groove in the middle, a V-shaped sliding groove on the right side of the T-shaped groove, and linear guide installation grooves symmetrically arranged on the two sides of the T-shaped groove. Two linear guide pairs are arranged on the linear guide installation grooves. The loading rear seat is arranged on the linear guide pair.

[0014] In an embodiment of the application, the stroke error measurement mechanism includes a circular magnetic grid measurement component, a laser ruler mounting table, two laser rulers and a stroke error work platform.

[0015] The circular magnetic grid measuring component is arranged at the connection between the measured screw pair and the integrated headstock, and the measured screw pair penetrates through the circular magnetic grid measuring component; the stroke error work platform is arranged on the work platform; the laser ruler mounting table is arranged at the outer edge end of the bedstock component, and two laser rulers are symmetrically arranged on the laser ruler mounting table.

[0016] In an embodiment of the present application, the circular magnetic grid measuring device comprises a screw clamp head tool, a magnetic grid adapter disc, a support unit, a reference sleeve, a cross roller bearing, a reading head connecting plate, a reading head, and a circular magnetic grid.

[0017] The reference sleeve is arranged on the integrated headstock, one side of the reference sleeve is provided with a support unit, the cross roller bearing is arranged on the end face of the integrated headstock and connected with the magnetic grid adapter disc, and the circular magnetic grid is arranged on the magnetic grid adapter disc; the reading head connecting plate is arranged inside the integrated headstock, and the reading head is arranged on the reading head connecting plate; the screw clamp head tool is connected with the magnetic grid adapter disc.

[0018] In an embodiment of the present application, the stroke error work platform comprises a moving upper plate, a mirror, a mirror mounting table, a moving upper plate cross roller guide rail, a probe fixing block, a work platform cross roller guide rail, a probe device adjusting block, a rotating handle, and a probe mounting shaft; the moving upper plate is arranged on the moving workbench; the mirror mounting table is fixedly arranged on the moving upper plate, and the mirror mounting table is fixedly provided with a mirror; the moving upper plate cross roller guide rail is provided with a moving upper plate, and the probe fixing block is arranged on the moving upper plate and connected with the moving upper plate cross roller guide rail in a sliding manner; the moving workbench is provided with a work platform cross roller guide rail, and the moving upper plate is connected with the moving workbench in a sliding manner through the work platform cross roller guide rail; the probe device adjusting block is arranged on the moving upper plate, the rotating handle is arranged on the bottom of the probe fixing block, and the probe fixing block is further provided with a probe mounting shaft.

[0019] In an embodiment of the present application, the friction torque measuring mechanism comprises a Y-shaped frame, a load cell, a friction torque measuring receiving rod, a measured lead screw nut and a nut extension rod; wherein the Y-shaped frame is fixedly connected with the movable workbench, and the load cell is installed directly below the Y-shaped frame; the measured lead screw nut is arranged on the measured lead screw pair, and is arranged on the outer edge of the middle through hole of the movable workbench; two shaft holes for transition fit insertion of the nut extension rod are symmetrically arranged on the measured lead screw nut, and the axis of the nut extension rod inserted into the shaft hole is horizontal to the axis of the measured lead screw pair; the Y-shaped frame top has a clamping groove for insertion of the friction torque measuring receiving rod, and the axis of the friction torque measuring receiving rod inserted into the clamping groove is located in the same horizontal plane as the axis of the measured lead screw pair.

[0020] In an embodiment of the present application, the contact stiffness measuring mechanism comprises a measured lead screw tension sensor, a reference disc, a plurality of contour blocks, a clamp disc, a lead screw clamp ring, a flange sleeve, a horizontal displacement sensor and a vertical displacement sensor; wherein the measured lead screw tension sensor is connected with one side of the measured lead screw nut through a transition plate arranged on one side, and the other side of the measured lead screw tension sensor is fixedly connected with the movable workbench; from the direction of the movable workbench to the integrated head frame, the flange sleeve, the reference disc, the plurality of contour blocks, the clamp disc and the lead screw clamp ring are sequentially arranged from the other side of the measured lead screw nut;

[0021] The plurality of contour blocks are arranged around the reference disc and the clamp disc; the lead screw clamp ring is arranged on the measured lead screw, and the clamp disc is arranged on the lead screw clamp ring; a plurality of vertical displacement sensors are distributed along the circumferential direction of the clamp disc at equal intervals, and the measuring head of the vertical displacement sensor is in contact with the reference disc; the horizontal displacement sensor is arranged on the clamp disc, and the measuring head of the horizontal displacement sensor is in contact with a deflection tool mounted on the reference disc.

[0022] In an embodiment of the present application, the temperature measuring mechanism comprises a first temperature sensor probe, a second temperature sensor probe and a third temperature sensor probe; a first double-rod telescopic air cylinder is mounted on the side of the middle part of the integrated headstock, the end of the telescopic rod of the first double-rod telescopic air cylinder is connected with a first air cylinder fixing plate, and the first air cylinder fixing plate is connected with a second double-rod telescopic air cylinder; the end of the telescopic rod of the second double-rod telescopic air cylinder is connected with a temperature sensor probe fixing plate, and the first temperature sensor probe is arranged on the temperature sensor probe fixing plate; a second air cylinder fixing plate is mounted on the moving workbench, and a third double-rod telescopic air cylinder is mounted on the second air cylinder fixing plate; the second temperature sensor probe is arranged at the end of the telescopic rod of the third double-rod telescopic air cylinder; a third air cylinder fixing plate is arranged on the tailstock, a fourth double-rod telescopic air cylinder is mounted on the third air cylinder fixing plate, and the third temperature sensor probe is arranged at the end of the fourth double-rod telescopic air cylinder.

[0023] Compared with the prior art, the present application has at least the following beneficial effects:

[0024] (1) The integrated headstock design effectively reduces the number of times of aligning the headstock and tailstock axes during installation, reducing the installation difficulty. In addition, under the premise of ensuring the reliability and stability of the headstock structure, the integrated headstock can reduce the width of the test bench, playing a key role in weight reduction and structural optimization of the test bench. The double-motor top loading method can ensure high-speed testing, and the synchronization device ensures the synchronization of the loading lead screws, thereby realizing accurate loading and measurement, avoiding the problems of uneven loading or poor synchronization in traditional devices.

[0025] (2) The present application adopts the integrated design of the weighing type force sensor at the Y-shaped frame and the working platform, which can realize friction torque measurement without disassembling the lead screw shaft end. Compared with the traditional method, the traditional friction torque measurement usually needs to disassemble the lead screw pair several times, resulting in waste of time and labor. The present application significantly reduces the time consumption and operation complexity in the disassembly and assembly process by measuring in situ. Repeated disassembly of the lead screw pair may cause physical damage to the lead screw shaft end and may introduce precision errors. The present application effectively reduces the risk of damage to the lead screw shaft end by avoiding disassembly operation, and ensures the stability and high precision of the measurement process.

[0026] (3) In the stroke error measurement method, the laser ruler and the circular magnetic grid are combined to form a measurement structure, and the circular magnetic grid is installed on the motor end, which innovatively eliminates the interference of the installation problem of the screw disassembly on the measurement result. In the traditional measurement method, the long grating is directly placed on the bed, and the oil splashed during work falls on the long grating and is not cleaned in time, which will affect the measurement accuracy. The laser ruler effectively avoids the working area, and the reflector is also on the table, which optimizes the measurement environment and improves the measurement accuracy and stability.

[0027] (4) The temperature sensor automatic fitting structure driven by the double-rod cylinder has higher measurement accuracy and automation level compared with the traditional manual measurement method. The sensor is controlled by the cylinder to be attached to the surface of the screw at a constant pressure, and the waist-shaped hole structure is combined to realize flexible adjustment of the temperature measuring head position, effectively avoiding the raceway and ensuring the accuracy of the measuring point, and significantly improving the accuracy and consistency of temperature measurement.

[0028] (5) The contact stiffness measurement scheme of the displacement sensor and the pressure sensor works cooperatively, realizes synchronous high-precision measurement of axial load and micro displacement under the premise of maintaining the original assembly state of the screw pair, and designs a screw rotation compensation device. Compared with the traditional method of repeatedly disassembling and assembling the screw pair, this method has the advantages of strong non-interference, high measurement accuracy, good repeatability and high test efficiency, effectively improving the reliability and practicality of high-precision screw pair contact stiffness evaluation.

[0029] (6) The device can evaluate the long-term performance stability and reliability of the ball screw in the electric power steering system, effectively avoid the shaft end damage and assembly error caused by repeated disassembly in traditional testing, significantly improve the test efficiency and data accuracy, and provide reliable technical support for high-precision performance evaluation and reliability research of electric vehicle precision transmission parts.

[0030] Additional aspects and advantages of the application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0031] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, taken in conjunction with the accompanying drawings, in which:

[0032] Figure 1 It is a whole structure schematic view of a disassembly-free ball screw pair precision retention loading test device of the application;

[0033] Figure 2 It is a structure schematic view of a bed body part of a disassembly-free ball screw pair precision retention loading test device of the application;

[0034] Figure 3 Structure diagram of a driving mechanism of a precision retention loading test device for a dismount-free ball screw pair according to the present application;

[0035] Figure 4 Structure diagram of a loading mechanism of a precision retention loading test device for a dismount-free ball screw pair according to the present application;

[0036] Figure 5 Structure diagram of a laser ruler mounting table of a precision retention loading test device for a dismount-free ball screw pair according to the present application;

[0037] Figure 6 Structure diagram of a circular magnetic grating measuring component of a precision retention loading test device for a dismount-free ball screw pair according to the present application;

[0038] Figure 7 Structure diagram of a stroke error working platform of a precision retention loading test device for a dismount-free ball screw pair according to the present application;

[0039] Figure 8 Structure diagram of a friction torque measuring mechanism of a precision retention loading test device for a dismount-free ball screw pair according to the present application;

[0040] Figure 9 Structure diagram of a precision retention loading test device for a dismount-free ball screw pair according to the present application;

[0041] Figure 10 Structure diagram of a contact stiffness measuring mechanism of a precision retention loading test device for a dismount-free ball screw pair according to the present application;

[0042] Figure 11 Structure diagram of a first temperature sensor measuring head of a precision retention loading test device for a dismount-free ball screw pair according to the present application;

[0043] Figure 12 Structure diagram of a temperature measuring mechanism of a precision retention loading test device for a dismount-free ball screw pair according to the present application.

[0044] As shown in the figure: 1, bed part; 1.1 bed body; 1.2, linear guide pair; 1.3, guide rail pressing block; 1.4, limiting support; 1.5, locking guide rail; 1.6, drag chain; 1.7, drag chain slot;

[0045] 2, drive mechanism; 2.2, drive motor; 2.4, tailstock; 2.5, measured screw pair; 2.7, motor end coupling; 2.8, measured screw nut; 2.9, first extension rod; 2.10, screw end coupling; 2.11, mechanical limit sensor; 2.12, zero position sensor;

[0046] 3, loading mechanism; 3.1, loading motor; 3.3, locking nut; 3.4, thrust combined bearing; 3.5, loading screw; 3.6, deep groove ball bearing; 3.8, loading rear seat; 3.9, loading nut; 3.10, loading tension and compression sensor; 3.12, first coupling; 3.13, second extension rod, 3.14, second coupling;

[0047] 4, stroke error measurement mechanism; 4.5, laser ruler installation table; 4.6, laser ruler; 4.11, stroke error workbench; 4.12, circular magnetic grid measurement component; 4.13, screw chuck tooling; 4.14, magnetic grid adapter disc; 4.15, support unit; 4.16, reference sleeve; 4.17, crossed roller bearing; 4.18, reading head connecting plate; 4.19, reading head; 4.20, circular magnetic grid; 4.21, mirror;

[0048] 4.22, mirror installation table; 4.23, moving upper plate; 4.24, moving upper plate crossed roller guide rail; 4.26, measuring head installation shaft; 4.27, workbench crossed roller guide rail; 4.28, measuring head device adjusting block; 4.29, rotating handle; 4.30, measuring head fixing block;

[0049] 5, friction torque measurement mechanism; 5.2, Y-type frame; 5.3, friction torque measurement receiving rod; 5.7, nut extension rod; 5.8, weighing type force sensor;

[0050] 6, contact stiffness measurement mechanism; 6.8, locking chuck seat; 6.9, screw chuck ring; 6.10, deflection tooling; 6.11, clamp disc; 6.12, equal height block; 6.14, adapter plate; 6.15, measured screw tension and compression sensor; 6.16, flange sleeve; 6.17, reference disc; 6.18, horizontal displacement sensor; 6.19, vertical displacement sensor;

[0051] 7, temperature measurement mechanism; 7.2, first temperature sensor measuring head; 7.3, temperature sensor measuring head fixing plate; 7.4, first double rod telescopic cylinder; 7.5, first cylinder fixing plate; 7.6, second double rod telescopic cylinder; 7.8, second cylinder fixing plate; 7.9, third double rod telescopic cylinder; 7.10, second temperature sensor measuring head; 7.11, third temperature sensor measuring head; 7.12, fourth double rod telescopic cylinder; 7.13, third cylinder fixing plate;

[0052] 8, integrated headstock; 9, moving worktable. DETAILED DESCRIPTION

[0053] Embodiments of the present application are described below in detail, examples of which are shown in the drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0054] An undismountable ball screw pair precision retention loading test device of an embodiment of the present application is described below in combination with the drawings.

[0055] The undismountable ball screw pair precision retention loading test device provided by the embodiment of the present application can be applied to performance evaluation of core transmission components in application scenarios such as precision grinding machines and small and medium-sized machining centers, and is especially high-precision and high-efficiency detection of key indicators such as stroke error, friction torque, contact stiffness and temperature distribution of the ball screw pair.

[0056] As shown in Figures 1-12 The undismountable ball screw pair precision retention loading test device of the embodiment of the present application can include a bed component 1, a driving mechanism 2, an integrated headstock 8, a moving worktable 9, two loading mechanisms 3, a stroke error measurement mechanism 4, a friction torque measurement mechanism 5, a contact stiffness measurement mechanism 6 and a temperature measurement mechanism 7.

[0057] The stroke error measurement mechanism 4 is arranged on the bed component 1.

[0058] The friction torque measurement mechanism 5 is arranged on the moving worktable 9.

[0059] The contact stiffness measurement mechanism 6 is also arranged on the moving worktable 9.

[0060] The moving worktable 9 is provided with a zero sensor 2.12 and two mechanical limit sensors 2.11 on the side.

[0061] It should be noted that the zero sensor 2.12 provided in the above embodiment is used to calibrate and control the starting reference position of the moving worktable, and the mechanical limit sensor 2.11 is used to prevent the moving worktable 9 from over-traveling, thereby improving the operation safety and reliability of the system.

[0062] The driving mechanism 2 and the two loading mechanisms 3 are arranged on the bed component 1, the integrated headstock 8 is fixedly arranged at one end of the bed component 1, and the moving worktable 9 is arranged in the middle of the bed component 1. Three through holes are formed in the moving worktable 9.

[0063] It can be understood that the number of axis calibration during the installation process is reduced by the integral headstock 8, the assembly precision and the overall reliability are improved.

[0064] The driving mechanism 2 penetrates the middle of the integral headstock 8, and the two loading mechanisms 3 penetrate the two sides of the integral headstock 8. It should be noted that the headstock structure of the integral headstock 8 reduces the volume and weight of the headstock, reduces the number of axis calibration during the installation process, improves the assembly precision and the overall reliability.

[0065] The driving mechanism 2 includes a driving motor 2.2, a measured lead screw pair 2.5, a tailstock 2.4, a lead screw end coupling 2.10, a motor end coupling 2.7 and a first extension rod 2.9.

[0066] The driving motor 2.2 is arranged at one end of the bedstock component 1, and the tailstock 2.4 is arranged at the other end of the bedstock component 1.

[0067] One end of the motor end coupling 2.7 connected to the output shaft of the driving motor 2.2 is arranged inside the integral headstock 8, the other end of the motor end coupling 2.7 is connected to the first extension rod 2.9, and the other end of the first extension rod 2.9 is connected to the lead screw end coupling 2.10, so that the driving motor 2.2 directly drives the measured lead screw pair 2.5 to rotate.

[0068] The measured lead screw pair 2.5 is arranged between the integral headstock 8 and the tailstock 2.4, penetrates the through hole in the middle of the moving workbench 9, one end of the measured lead screw pair 2.5 is connected to the lead screw end coupling 2.10, and the other end of the measured lead screw pair 2.5 is connected to the tailstock 2.4.

[0069] The temperature measuring mechanism 7 is arranged on the driving mechanism 2.

[0070] It should be noted that the friction torque measuring mechanism 5 described in the above embodiment is responsible for detecting the friction performance of the measured lead screw pair 2.5. The contact stiffness measuring mechanism 6 is used to accurately obtain the axial force-displacement response. The temperature measuring mechanism 7 is used to monitor the temperature rise change during the test process.

[0071] Further, the device is also matched with an external magnetic vibration measuring device to collect vibration characteristic data of the measured lead screw pair 2.5. The device can be directly adsorbed on the lead screw pair flange sleeve 6.16 to realize real-time monitoring of the vibration state during operation, so as to effectively identify the abnormal behavior or potential failure of the measured lead screw pair 2.5 in work, and improve the sensitivity and reliability of detection.

[0072] In an embodiment of the present application, as shown inFigure 4 As shown, the loading mechanism 3 comprises a loading motor 3.1, a thrust combined bearing 3.4, a loading screw 3.5, a deep groove ball bearing 3.6, a loading nut 3.9, a loading position tensile and compressive force sensor 3.10, a second extension rod 3.13, a first coupling 3.12 and a second coupling 3.14.

[0073] Two loading motors 3.1 are respectively arranged on the two sides of the driving motor 2.2, so as to ensure the loading centering and test accuracy, and the two loading motors 3.1 are synchronously driven to realize the synchronous movement of the loading screw 3.5.

[0074] The output of each driving motor 2.2 passes through the integrated headstock 8 and is connected with one end of the second coupling 3.14 arranged inside the integrated headstock 8, the other end of the second coupling 3.14 is connected with one end of the second extension rod 3.13, and the other end of the second extension rod 3.13 is connected with one end of the first coupling 3.12.

[0075] It should be noted that the driving motor 2.2 is synchronously driven to realize the synchronous movement of the measured screw pair 2.5 in the above embodiment.

[0076] The other end of the first coupling 3.12 is connected with one end of the thrust combined bearing 3.4, and one end of the thrust combined bearing 3.4 is connected with one end of the loading screw 3.5.

[0077] It should be noted that the output shaft of the driving motor 2.2 is connected with the shaft end of the loading screw 3.5 through the second coupling 3.14, the extension rod 3.13 and the first coupling 3.12, so as to realize the direct driving rotation of the motor to the loading screw 3.5 in the above embodiment.

[0078] As a possible case, in order to prevent the axial movement of the loading screw 3.5, the locking nut 3.3 can be used for positioning and fastening at the shaft end of the loading screw 3.5.

[0079] The other ends of the two loading screws 3.5 are connected with the deep groove ball bearings 3.6 after passing through the through holes on the two sides of the movable workbench 9, and the deep groove ball bearings 3.6 are arranged on the loading rear seat 3.8.

[0080] The loading position tensile and compressive force sensor 3.10 is arranged at the connection between the loading screw 3.5 and the side of the workbench close to the loading rear seat 3.8.

[0081] The loading nut 3.9 is sleeved on the loading screw 3.5 and connected with the loading position tensile and compressive force sensor 3.10.

[0082] In one embodiment of the present application, as shown inFigure 2 As shown in the drawings, the bed body part 1 comprises a bed body 1.1, a linear guide rail pair 1.2, a limiting support 1.4 and a locking guide rail 1.5;

[0083] The locking guide rail 1.5 is arranged on the bed body 1.1, the limiting support 1.4 is arranged on the locking guide rail 1.5, and the position of the limiting support 1.4 and the positions of the zero sensor 2.12 and the mechanical sensor 2.11 correspond to each other. It should be noted that the limiting support is provided to trigger the mechanical limiting sensor 2.11 and the zero sensor 2.12 installed on the side of the moving workbench 2.3;

[0084] The bed body 1.1 is provided with a T-shaped sliding groove in the middle, a V-shaped sliding groove on the right side of the T-shaped groove, and linear guide rail mounting grooves symmetrically arranged on both sides of the T-shaped groove;

[0085] Two linear guide rail pairs 1.2 are arranged on the linear guide rail mounting grooves. The linear guide rail pair 1.2 is provided with a loading butt 3.8.

[0086] It should be noted that the bed body 1.1 described in the above embodiment can be provided with a drag chain groove 1.7 on the side, and the drag chain groove 1.7 is provided with a drag chain 1.6 for accommodating and guiding the orderly movement of the cable and the air pipe. Among them, the cable is used to transmit electrical signals, and the air pipe is used to ensure the normal work of the cylinder.

[0087] In an embodiment of the present application, as shown in the drawings, Figure 5 The stroke error measuring mechanism 4 comprises a circular magnetic grid measuring part 4.12, a laser ruler mounting table 4.5, two laser rulers and a stroke error working platform 4.11;

[0088] The circular magnetic grid measuring part 4.12 is arranged at the connection between the measured lead screw pair 2.5 and the integrated headstock 8, and the measured lead screw pair 2.5 penetrates the circular magnetic grid measuring part 4.12;

[0089] The stroke error working platform 4.11 is arranged on the working platform;

[0090] The laser ruler mounting table 4.5 is arranged at the outer edge end of the bed body part 1, and two laser rulers are symmetrically arranged on the laser ruler mounting table 4.5.

[0091] In an embodiment of the present application, as shown in the drawings, Figure 6 The circular magnetic grid measuring device comprises a lead screw chuck tool 4.13, a magnetic grid adapter disc 4.14, a support unit 4.15, a reference sleeve 4.16, a cross roller bearing 4.17, a reading head connecting plate 4.18, a reading head 4.19 and a circular magnetic grid 4.20;

[0092] The reference sleeve 4.16 is installed on the integrated headstock 8, and a support unit 4.15 is installed on one side of the reference sleeve 4.16. The cross roller bearing 4.17 is arranged on the end face of the integrated headstock 8 and connected with the magnetic grid adapter disk 4.14. The circular magnetic grid 4.20 is installed on the magnetic grid adapter disk 4.14.

[0093] It can be understood that, in order to ensure the installation accuracy of the measured screw pair 2.5, one end of the measured screw pair 2.5 is fixed in the reference sleeve 4.16 installed on the integrated headstock, and the support unit 4.15 is installed on the free end of the measured screw pair 2.5. The free end is stably supported by the support unit 4.15 to limit the radial movement of the screw.

[0094] The read head connecting plate 4.18 is installed inside the integrated headstock 8, and the read head 4.19 is installed on the read head connecting plate 4.18. The screw chuck tool 4.13 is connected with the magnetic grid adapter disk 4.14. It can be understood that the read head 4.19 is provided to obtain the rotation information of the measured screw pair 2.5. It should be noted that the circular magnetic grid 4.20 is installed on the cross roller bearing 4.17 through the magnetic grid adapter disk 4.14, and the high-precision rotation characteristics of the cross roller bearing 4.17 can be used to ensure the rotation coaxiality of the circular magnetic grid 4.20.

[0095] Specifically, the measured screw pair 2.5 is clamped by the screw chuck tool 4.13, and the screw chuck tool 4.13 is in transmission connection with the shaft on the magnetic grid adapter disk 4.14, so that when the measured screw pair 2.5 rotates, the magnetic grid adapter disk 4.14 and the circular magnetic grid 4.20 can be driven to rotate synchronously through the shaft. The relative position of the read head 4.19 and the circular magnetic grid 4.20 can be adjusted through the read head connecting plate 4.18, so that the two maintain a predetermined gap to real-time collect and record the actual rotation number of the measured screw pair 2.5. Combined with the known lead parameter of the measured screw pair 2.5 and the actual rotation number, the theoretical movement distance of the measured screw nut 2.9 can be calculated.

[0096] In one embodiment of the present application, as shown in Figure 7 The stroke error working platform 4.11 includes a moving upper plate 4.23, a mirror 4.21, a mirror mounting table 4.22, a moving upper plate cross roller guide rail 4.24, a probe fixing block 4.30, a working platform cross roller guide rail 4.27, a probe device adjusting block 4.28, a rotating handle 4.29, and a probe mounting shaft 4.26.

[0097] The moving upper plate 4.23 is arranged on the moving workbench 9.

[0098] The mirror mounting table 4.22 is fixedly installed on the moving upper plate 4.23, and a mirror 4.19 is fixedly installed on the mirror mounting table 4.22;

[0099] Specifically, the laser beam emitted by the laser ruler 4.6 is directly incident on the mirror 4.21 of the stroke error work platform 4.11, and the mirror 4.21 reflects the laser beam back to the laser ruler 4.6, and the laser ruler 4.6 calculates the corresponding actual displacement data by receiving the reflected light beam.

[0100] The moving upper plate 4.23 is arranged on the moving upper plate cross roller guide 4.24, and the probe fixing block 4.30 is installed on the moving upper plate 4.23 and is in sliding connection with the moving upper plate cross roller guide 4.24;

[0101] The moving workbench 9 is provided with a work platform cross roller guide 4.27, and the moving upper plate 4.23 is in sliding connection with the moving workbench 9 through the work platform cross roller guide 4.27;

[0102] The probe device adjusting block 4.28 is installed on the moving upper plate 4.23, the rotating handle 4.29 is arranged on the bottom of the probe fixing block 4.30, and the probe fixing block 4.30 is further provided with a probe mounting shaft 4.26.

[0103] Specifically, the laser ruler 4.6 is adjusted to ensure that the laser beam is accurately incident on the center of the mirror 4.21, and the moving workbench 9 can be stably moved along the axis direction of the measured screw pair 2.5 through the work platform cross roller guide 4.27. The rotating handle 4.29 can drive the probe device adjusting block 4.28 to move, and then the position of the probe on the probe mounting shaft 4.26 is adjusted through the probe fixing block 4.30, so as to realize the auxiliary positioning and calibration of the measured screw pair 2.5 or the work platform 4.8, and further ensure the accuracy of the measurement reference.

[0104] It should be noted that, in order to ensure the accuracy of the measurement result, the loading nut 3.9 and the moving workbench need to be completely separated before testing, so as to eliminate the interference of the loading nut 3.9 on the moving workbench. Then, the moving workbench is moved along the work platform cross roller guide 4.27 by the measured screw pair 2.5. Since the moving workbench 9 is fixedly connected with the measured screw nut 2.8, the actual moving distance of the moving workbench 9 is the actual displacement of the measured screw nut 2.8. By comparing the actual displacement measured by the laser ruler 4.6 with the theoretical moving distance calculated by the circular magnetic grating measuring device 4.12, the stroke error of the measured screw pair 2.5 can be accurately measured.

[0105] In an embodiment of the present application, as Figure 8As shown, the friction torque measuring mechanism 5 includes a Y-shaped frame 5.2, a load cell 5.8, a friction torque measuring receiving rod 5.3, a measured screw nut 2.8, and a nut extension rod 5.7;

[0106] The Y-shaped frame 5.2 is fixedly connected to the moving workbench 9, and the load cell 5.8 is installed directly below the Y-shaped frame 5.2.

[0107] Thus, the sensor 5.8 and the Y-shaped frame 5.2 can be ensured to have no relative displacement with the moving workbench to provide a stable force signal acquisition reference. During measurement, the moving workbench 9 is completely separated, so that the measured screw nut 2.8 is only subjected to the driving action of the lead screw.

[0108] The measured screw nut 2.8 is arranged on the measured lead screw pair 2.5, and the measured screw nut 2.8 is arranged on the outer edge of the middle through hole of the moving workbench 9.

[0109] Two shaft holes are symmetrically arranged on the measured screw nut 2.8 for transition fit insertion of the nut extension rod 5.7, and the axis of the nut extension rod 5.7 inserted into the shaft hole is horizontal to the axis of the measured lead screw pair 2.5.

[0110] The Y-shaped frame 5.2 has a clamping groove at the top for insertion of the friction torque measuring receiving rod 5.3, and the axis of the friction torque measuring receiving rod 5.3 inserted into the clamping groove is in the same horizontal plane as the axis of the measured lead screw pair 2.5.

[0111] Specifically, during friction torque measurement, the one end of the nut extension rod 5.7 is inserted into the shaft hole of the measured screw nut 2.8 through transition fit to ensure that the nut extension rod 5.7 rotates synchronously with the measured screw nut 2.8 and the axis is horizontal to the axis of the measured lead screw pair 2.5. Then the friction torque measuring receiving rod 5.3 is horizontally inserted into the pre-set clamping groove at the top of the Y-shaped frame 5.2, and the clamping groove limits the axis of the friction torque measuring receiving rod 5.3 to be in the same horizontal plane as the axis of the measured lead screw pair 2.5. At the same time, the position of the friction torque measuring receiving rod 5.3 is adjusted so that the free end of the nut extension rod 5.7 away from the measured screw nut 2.8 is stably rested on the middle cylindrical surface of the friction torque measuring receiving rod 5.3, and the contact point is located at the intersection of the two axes to avoid force signal error.

[0112] When the driving motor 2.2 drives the measured lead screw to rotate around its own axis, at this time the friction torque measurement receiving rod 5.3 is fixed to the moving workbench 9 through the Y-shaped frame 5.2, and the free end of the nut extension rod 5.7 is prevented from rotating, the vertical downward radial pressure generated by the rotation tendency of the nut extension rod 5.7 is transmitted to the receiving rod friction torque measurement receiving rod 5.3 through the contact point with the receiving rod friction torque measurement receiving rod 5.3, and then conducted to the lower weighing type force sensor 5.8 through the Y-shaped frame 5.2, thereby achieving the effect of measuring the friction torque.

[0113] In one embodiment of the present application, as shown in Figure 10 The contact stiffness measurement mechanism 6 includes a measured lead screw tension sensor 6.15, a reference disc 6.17, a plurality of contour blocks 6.12, a clamp disc 6.11, a lead screw clamp ring 6.9, a flange sleeve 6.16, a horizontal displacement sensor 6.18 and a vertical displacement sensor 6.19.

[0114] The measured lead screw tension sensor 6.15 is connected to one side of the measured lead screw nut 2.8 through an adapter plate 6.14 provided on one side, and the other side of the measured lead screw tension sensor 6.15 is fixedly connected to the moving workbench 9. The measured lead screw nut 2.8 is firmly fixed with the measured lead screw tension sensor 6.15 by bolt connection through the adapter plate 6.14, ensuring no loss of axial load transmission.

[0115] It should be noted that the measured lead screw tension sensor 6.15 in the above embodiment can monitor the axial tension and compression of the measured lead screw pair 2.5 in real time during the loading process, and realize dynamic evaluation of its precision retention.

[0116] From the direction of the moving workbench 9 to the integrated head frame 8, the other side of the measured lead screw nut 2.8 is sequentially provided with a flange sleeve 6.16, a reference disc 6.17, a plurality of contour blocks 6.12, a clamp disc 6.11, and a lead screw clamp ring 6.9.

[0117] A plurality of contour blocks 6.12 are arranged around the reference disc 6.17 and the clamp disc 6.11.

[0118] The lead screw clamp ring 6.9 is arranged on the measured lead screw (i.e. the lead screw part of the measured lead screw pair 2.5), and the clamp disc 6.11 is arranged on the lead screw clamp ring 6.9.

[0119] It should be noted that the measured lead screw nut 2.8 in the above embodiment is firmly fixed with the measured lead screw tension sensor 6.15 by bolt connection through the adapter plate 6.14, ensuring no loss of axial load transmission.

[0120] To establish a measurement reference and ensure the measurement posture level, the reference disc 6.17 is connected with the flange sleeve 6.16 in a matching structure and fixed by bolts, the flange sleeve 6.16 is radially extruded and fixed to the measured screw nut 6.13 through side bolts, and the jig disc 6.11 keeps a strict horizontal state with the reference disc 6.17 through the equal-height block 6.12, so as to avoid the measurement error caused by the inclination of the reference.

[0121] A plurality of vertical displacement sensors 6.19 are distributed at equal intervals along the circumferential direction of the jig disc 6.11, and the measuring head of the vertical displacement sensor 6.19 is in contact with the reference disc 6.17;

[0122] The horizontal displacement sensor 6.18 is arranged on the jig disc 6.11, and the measuring head of the horizontal displacement sensor 6.18 is in contact with the deflection tool 6.10 arranged on the reference disc 6.17.

[0123] To accurately obtain the displacement data of the measured screw pair 2.5 under stress and compensate the experimental error, three vertical displacement sensors 6.19 are distributed on the jig disc 6.11, and the measuring head is in close contact with the surface of the reference disc 6.17, which is used to measure the displacement of the measured screw pair 6.7 under the action of axial load in real time, and a rotating measuring device is arranged on the measured screw, which is in contact with the deflection tool 6.10 arranged on the reference disc 6.17 through the measuring head of the horizontal displacement sensor 6.18, so as to compensate the experimental error caused by the rotation and torsion of the measured screw;

[0124] To prevent the measured screw pair 2.5 from being twisted and protect the driving motor 2.2, a locking chuck seat 6.8 can be assembled on the coupling near the measured screw pair 2.5, the locking chuck seat 6.8 is clamped and fixed with the coupling, and the bottom is fixedly connected with the integrated headstock 8 through bolts, so as to prevent the measured screw pair 2.5 from being twisted during the measurement process and avoid the damage of the driving motor 2.2 caused by the excessive rotating torque.

[0125] In the specific contact stiffness measurement process, first, the driving motor is controlled to be locked by its brake function, and the measured lead screw pair 2.5 is further fixed against rotation by the locking chuck seat, so as to ensure that the lead screw part of the measured lead screw pair 2.5 does not rotate. Subsequently, the loading motor applies a preset axial load to the measured lead screw pair 2.5 through the loading lead screw pair. Under the action of the axial load, the measured lead screw nut 2.8 produces a slight axial displacement relative to the lead screw part of the measured lead screw pair 2.5. The slight axial displacement is synchronously read and recorded by the three vertical displacement sensors. The corresponding axial load data is collected in real time by the measured lead screw tension sensor 6.15 and the loading tension sensor 3.10. Through the corresponding relationship between the obtained axial load data and the slight axial displacement data, the contact stiffness of the measured lead screw pair 2.5 can be accurately measured. The lead screw clamping ring 6.9 plays a role in auxiliary positioning and stable support for the lead screw part of the measured lead screw pair 2.5 during the entire measurement process, further ensuring the reliability of the measurement data.

[0126] In one embodiment of the present application, as shown in Figure 11 and Figure 12 The temperature measuring mechanism 7 includes a first temperature sensor probe 7.2, a second temperature sensor probe 7.10, and a third temperature sensor probe 7.11.

[0127] A first double-rod telescopic cylinder 7.4 is mounted on the side of the middle part of the integrated head frame 8. The end of the telescopic rod of the first double-rod telescopic cylinder 7.4 is connected with a first cylinder fixing plate 7.5. The first cylinder fixing plate 7.5 is connected with a second double-rod telescopic cylinder 7.6.

[0128] The end of the telescopic rod of the second double-rod telescopic cylinder 7.6 is connected with a temperature sensor probe fixing plate 7.3. The temperature sensor probe fixing plate 7.3 is provided with the first temperature sensor probe 7.2.

[0129] The temperature sensor probe fixing plate 7.3 adopts a waist-shaped hole design, which facilitates the axial fine adjustment of the first temperature sensor 7.2 probe, so that the probe avoids the raceway and closely adheres to the surface of the measured lead screw pair 2.5, thereby realizing accurate measurement of the temperature of the head of the measured lead screw.

[0130] A second cylinder fixing plate 7.8 is mounted on the moving workbench 9. The second cylinder fixing plate 7.8 is mounted with a third double-rod telescopic cylinder 7.9. The end of the telescopic rod of the third double-rod telescopic cylinder 7.9 is provided with a second temperature sensor probe 7.10. The second temperature sensor probe 7.10 is provided for measuring the middle temperature of the lead screw. A third temperature sensor probe 7.11 is provided for collecting the tail temperature of the measured lead screw pair 2.5.

[0131] The tailstock 2.4 is provided with a third cylinder fixing plate 7.13, and the fourth double-rod telescopic cylinder 7.12 is installed on the third cylinder fixing plate 7.13, and the end of the fourth double-rod telescopic cylinder 7.12 is provided with a third temperature sensor probe 7.11.

[0132] Specifically, when the screw pair needs to be measured, one end of the measured screw pair 2.5 is installed in the support unit 4.15 of the integrated headstock 8, the other end is fixed in the integrated structure of the tailstock 2.4, and the screw shaft end is fastened by the locking nut 3.3 to prevent axial movement. The measured screw nut 2.8 of the measured screw pair 2.5 is installed on the measured screw tension sensor 6.15 on the moving workbench 9 through bolts, realizing the force transmission and measurement function. After starting the driving motor 2.2 and the loading motor 3.1, the driving motor 2.2 drives the measured screw pair 2.5 to rotate, and the loading motor 3.1 synchronously drives the loading screw 3.5 to rotate. Since the measured screw nut 2.8 and the loading nut 3.9 are both fixed on the moving workbench 9 through bolts, the rotation of the loading nut 3.9 will drive the moving workbench 9 to move axially. The system controls the rotation direction and speed of the two motors accurately, so that the two nuts move synchronously in the same direction and at the same linear speed, thereby driving the moving workbench 9 to move to the zero position sensor 2.12 and trigger, calibrating the initial position, and then stopping the driving motor 2.2 and the loading motor 3.1. According to the effective stroke of the measured screw pair 2.5, the limit support 1.4 is adjusted to a reasonable position to ensure that the moving workbench 9 does not exceed the safe stroke during movement; once the mechanical limit sensor 2.11 is triggered, the system will immediately stop the motor to ensure safety. Before entering the test stage, the operator can set the test parameters such as load, test speed and running laps through the upper computer software. The tension sensor installed on the moving workbench 9, the measured screw tension sensor 6.15 and the loading tension sensor 3.10, monitors and records the axial load in real time, and adjusts the rotation speed and torque output of the two loading motors 3.1 to realize accurate control of the load and movement speed, thereby ensuring that the test process proceeds stably according to the preset working condition.

[0133] I. Travel error measurement

[0134] When the travel error is measured, the test software sets the test travel error required test speed, effective travel and other parameters, and then starts the drive motor 2.2 to drive the measured screw pair 2.5 to rotate. Since the measured screw nut 2.8 is connected with the moving workbench 9, the moving distance of the measured screw nut 2.8 can be reflected by the moving distance of the moving workbench 9. In order to ensure the accuracy of the travel error test, the loading nut 3.9 of the loading screw 3.5 on both sides is disconnected with the moving workbench 9 during the measurement, and the actual moving distance of the nut is measured by the laser ruler 4.6 installed on the bed body 1.1 (installed on the laser ruler mounting table (4.5)); the theoretical moving distance of the measured screw nut 2.8 is measured by the circular magnetic grid measuring component 4.12 installed on the integrated headstock 8. The screw chuck tool 4.13 is used to clamp the measured screw pair 2.5, and the screw chuck tool 4.13 is connected with the magnetic grid adapter disc 4.14 through the shaft. When the measured screw pair 2.5 rotates, the magnetic grid adapter disc 4.14 and the circular magnetic grid 4.20 can rotate, and the theoretical moving distance of the measured screw nut 2.8 can be obtained through the reading head 4.19. The circular magnetic grid 4.20 is installed at the motor end, which innovatively eliminates the interference of screw assembly and disassembly on the measurement results.

[0135] II. Friction torque test

[0136] Before the friction torque test is carried out, the corresponding test parameters need to be preset through the test software, and the test parameters include test speed, effective travel and other key parameter information; then, the measured screw nut 2.8 is completely disconnected with the moving workbench 9, so that the measured screw nut 2.8 is only driven by the rotation of the measured screw pair 2.5, and then one end of the nut extension rod 5.7 is inserted into the preset hole of the measured screw nut 2.8, and the other end is stably rested on the friction torque measurement receiving rod 5.3 on the Y-shaped frame 5.2, and the force acting on the nut extension rod 5.7 is transmitted to the weighing force sensor 5.8 below through the friction torque measurement receiving rod 5.3. In order to ensure the accuracy of the measurement results, the loading nut 3.9 needs to be disconnected with the moving workbench 9 to eliminate the interference of the loading force on the friction torque test results; after the above test preparation work is completed, the drive motor 2.2 is started to drive the measured screw pair 2.5 to rotate around its own axis without additional load. During the rotation process, the nut extension rod 5.7 is limited by the Y-shaped frame 5.2 through the friction torque measurement receiving rod 5.3 due to the tendency of the nut to rotate, which prevents it from rotating synchronously with the measured screw nut 2.8, and then under the condition that the relative rotation of the measured screw nut 2.8 is limited, the corresponding force signal is collected through the weighing force sensor 5.8 to realize the accurate measurement of the friction torque of the measured screw pair 2.5. Through the above structure setting and operation steps, the test method effectively isolates the influence of external interference factors on the test process, and significantly improves the stability and accuracy of the friction torque measurement results.

[0137] Three, contact stiffness measurement

[0138] In the contact stiffness measurement process, the measured ball screw nut 2.8 is firmly fixed with the measured ball screw tension sensor 6.15 by bolt connection through the adapter plate 6.14, realizing the accurate transmission of force, the reference disc 6.17 is connected with the flange sleeve 6.16 by matching structure and bolt fixing, the flange sleeve 6.16 is fixed radially by side bolt to the measured ball screw nut 2.8, the clamp disc 6.11 keeps strict horizontal state with the flange sleeve 6.16 through the equal height block 6.12 to establish a stable measurement reference, the locking chuck seat is fixed with the shaft coupling close to the measured ball screw pair 2.5 and its bottom is fixed and connected with the integrated headstock 8 through bolt, at the same time, the driving motor 2.2 uses its brake function to lock, which realizes the anti-rotation fixation of the measured ball screw pair 2.5 together, avoiding the torsion of the measured ball screw pair 2.5 and the damage of the driving motor 2.2 during the measurement process; before testing, ensure that the loading tension sensor 3.10 and the measured ball screw tension sensor 6.15 are fixed and installed on the movable workbench 9, the multiple vertical displacement sensors 6.19 are distributed on the clamp disc 6.11 and their measuring heads are in close contact with the surface of the reference disc 6.17, and the measuring head of the horizontal displacement sensor 6.18 is in contact with the deflection tooling 6.10 installed on the reference disc 6.17; then, the loading motor 3.1 applies a preset axial load to the measured ball screw pair 2.5 through the loading ball screw 3.5, under the action of the axial load, the measured ball screw nut 2.8 produces a small axial displacement relative to the measured ball screw pair 2.5, the loading tension sensor 3.10 and the measured ball screw tension sensor 6.15 collect the axial load data in real time, the multiple vertical displacement sensors 6.19 synchronously read and record the small axial displacement data, the horizontal displacement sensor 6.18 and the deflection tooling 6.10 cooperate to realize the compensation of the experimental error caused by the rotation and torsion of the ball screw, through the corresponding relationship of the obtained axial load data and the small axial displacement data, the contact stiffness of the measured ball screw pair 2.5 can be accurately obtained.

[0139] Four, temperature measurement

[0140] In the temperature measurement, firstly, the rotation of the driving motor 2.2 and the loading motor 3.1 is stopped by the test software to ensure the stability and operation safety of the measurement process. Then, the system executes the temperature measurement instruction, controls the first double-rod telescopic cylinder 7.4 and the second double-rod telescopic cylinder 7.6 to extend in turn, so that the first temperature sensor probe 7.2, the second temperature sensor probe and the third temperature sensor probe are installed on the temperature sensor probe fixing plate 7.3 and adhere to the surface of the measured screw pair 2.5 in turn. The adhesion time of each probe on the screw head, middle and tail is about 5 seconds to ensure the accuracy of the measurement data. After the measurement is completed, the cylinder automatically retracts, and the sensor is separated from the screw surface. The whole temperature measurement process is automatically controlled by the system, which is simple to operate, efficient, and has reliable data, and can realize accurate acquisition of the temperature of the screw at multiple positions.

[0141] In summary, the precision retention loading test device for the ball screw pair without disassembly in the embodiment of the application has the following advantages: (1) The integrated headstock design of the application effectively reduces the number of alignment of the headstock and tailstock axes during installation, thereby reducing the installation difficulty. In addition, under the premise of ensuring the reliability and stability of the headstock structure, the integrated headstock can reduce the width of the test bed, which plays a key role in weight reduction and structural optimization of the test bed. The double-motor top loading method can ensure high-speed testing, and the synchronization device ensures the synchronization of the loaded screw, thereby realizing accurate loading and measurement and avoiding the problems of uneven loading and poor synchronization in traditional devices.

[0142] (2) The application adopts the integrated design of the weighing type force sensor at the Y-shaped frame and the working platform, which can realize friction torque measurement without disassembling the screw shaft end. Compared with the traditional method, the traditional friction torque measurement usually needs to disassemble the screw pair multiple times, resulting in waste of time and labor. The application measures in situ, significantly reducing the time consumption and operation complexity in the disassembly and assembly process. Repeated disassembly of the screw pair may cause physical damage to the screw shaft end and may introduce precision errors. The application avoids disassembly operation, effectively reduces the risk of damage to the screw shaft end, and ensures the stability and high precision of the measurement process.

[0143] (3) In the travel error measurement method, the application adopts the measurement structure combining the laser ruler and the circular magnetic grating, and installs the circular magnetic grating on the motor end, which innovatively eliminates the interference of the installation problem of the screw assembly and disassembly on the measurement result from the structure. In the traditional measurement method, the long grating is directly placed on the bed, and if the oil splashed during work is not cleaned in time, it will affect the measurement accuracy. The laser ruler effectively avoids the working area, and the reflector is also on the table of the working table, which optimizes the measurement environment and improves the measurement accuracy and stability.

[0144] (4) The temperature sensor automatic pasting structure driven by the double-rod air cylinder has higher measurement accuracy and automation level compared with the traditional manual measurement mode. The sensor is pasted on the surface of the lead screw at constant pressure through the air cylinder control, and the flexible adjustment of the temperature measuring head position is realized in combination with the waist hole structure, the raceway is effectively avoided, the measuring point is ensured to be accurate, and the accuracy and consistency of temperature measurement are significantly improved.

[0145] (5) The contact stiffness measurement scheme of the displacement sensor and the pressure sensor works cooperatively, the synchronous high-precision measurement of the axial load and the slight displacement is realized on the premise of keeping the original assembly state of the lead screw pair, and a lead screw rotation compensation device is designed. Compared with the traditional method of repeatedly disassembling the lead screw pair for measurement, which is easy to introduce assembly error and has low efficiency, the method has the advantages of strong non-interference, high measurement accuracy, good repeatability and high test efficiency, and effectively improves the reliability and practicality of the high-precision lead screw pair contact stiffness evaluation.

[0146] (6) The device can evaluate the long-term performance stability and reliability of the ball screw in the electric power steering system, effectively avoid the shaft end damage and assembly error caused by repeated disassembly in the traditional test, significantly improve the test efficiency and data accuracy, and provide reliable technical support for the high-precision performance evaluation and reliability research of the precision transmission parts of the electric vehicle.

[0147] In the description of the present specification, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0148] In the description of the present specification, the description referring to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples without contradiction.

[0149] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and that changes, modifications, substitutions and variations can be made by those skilled in the art without departing from the scope of the present application.

Claims

1. A load testing device for the precision retention of a ball screw pair without disassembly, characterized in that, It includes a bed component (1), a drive mechanism (2), an integrated headstock (8), a moving worktable (9), two loading mechanisms (3), a stroke error measuring mechanism (4), a friction torque measuring mechanism (5), a contact stiffness measuring mechanism (6), and a temperature measuring mechanism (7); The stroke error measuring mechanism (4) is mounted on the bed component (1); The friction torque measuring mechanism (5) is mounted on the movable worktable (9), and the contact stiffness measuring mechanism (6) is also mounted on the movable worktable (9); The side of the mobile workbench (9) is equipped with a zero-position sensor (2.12) and two mechanical limit sensors (2.11). The drive mechanism (2) and the two loading mechanisms (3) are both mounted on the bed component (1), the integrated headstock (8) is fixedly mounted on one end of the bed component (1), and the movable worktable (9) is mounted in the middle of the bed component (1); the movable worktable (9) has three through holes. The drive mechanism (2) passes through the middle of the integrated head frame (8), and the two loading mechanisms (3) pass through the two sides of the integrated head frame (8); The drive mechanism (2) includes a drive motor (2.2), a lead screw pair under test (2.5), a tailstock (2.4), a lead screw end coupling (2.10), a motor end coupling (2.7), and a first extension rod (2.9). The drive motor (2.2) is located at one end of the bed component (1), and the tailstock (2.4) is located at the other end of the bed component (1). The output shaft of the drive motor (2.2) is connected to one end of the motor end coupling (2.7), which is located inside the integrated head frame (8). The other end of the motor end coupling (2.7) is connected to a first extension rod (2.9), and the other end of the first extension rod (2.9) is connected to a lead screw end coupling (2.10). A test lead screw pair (2.5) is installed between the integrated head frame (8) and the tail frame (2.4). The test lead screw pair (2.5) passes through the through hole in the middle of the movable worktable (9). One end of the test lead screw pair (2.5) is connected to the lead screw end coupling (2.10), and the other end of the test lead screw pair (2.5) is connected to the tail frame (2.4). The temperature measuring mechanism (7) is mounted on the driving mechanism (2).

2. The non-disassembly-free ball screw pair precision retention loading test device according to claim 1, characterized in that, The loading mechanism (3) includes a loading motor (3.1), a thrust combined bearing (3.4), a loading screw (3.5), a deep groove ball bearing (3.6), a loading nut (3.9), a loading point tension and compression sensor (3.10), a second extension rod (3.13), a first coupling (3.12), and a second coupling (3.14). The two loading motors (3.1) are located on both sides of the drive motor (2.2). The output of each drive motor (2.2) passes through the integrated head frame (8) and is connected to one end of the second coupling (3.14) inside the integrated head frame (8). The other end of the second coupling (3.14) is connected to one end of the second extension rod (3.13), and the other end of the second extension rod (3.13) is connected to one end of the first coupling (3.12). The other end of the first coupling (3.12) is connected to one end of the thrust combined bearing (3.4); one end of the thrust combined bearing (3.4) is connected to one end of the loading screw (3.5); The other ends of the two loading screws (3.5) pass through the through holes on both sides of the movable worktable (9) and are connected to deep groove ball bearings (3.6), which are mounted on the loading back seat (3.8); Both the loading screw (3.5) and the worktable near the loading seat (3.8) are equipped with loading tension and compression sensors (3.10). The loading nut (3.9) is sleeved on the loading screw (3.5) and connected to the loading tension sensor (3.10).

3. The non-disassembly-free ball screw pair precision retention loading test device according to claim 1, characterized in that, The bed component (1) includes a bed body (1.1), a linear guide pair (1.2), a limiting bracket (1.4), and a locking guide (1.5). The locking guide rail (1.5) is mounted on the bed body (1.1), the limiting bracket (1.4) is mounted on the locking guide rail (1.5), and the position of the limiting bracket (1.4) corresponds to the positions of the zero-position sensor (2.12) and the mechanical sensor (2.11). The bed body (1.1) is provided with a T-shaped slide groove in the middle, a V-shaped slide groove on the right side of the T-shaped slide groove, and linear guide rail mounting grooves symmetrically arranged on both sides of the T-shaped slide groove. Two linear guide pairs (1.2) are disposed on the linear guide mounting slots; a loading back seat (3.8) is mounted on the linear guide pairs (1.2).

4. The non-disassembly-free ball screw pair precision retention loading test device according to claim 1, characterized in that, The stroke error measuring mechanism (4) includes a circular magnetic grating measuring component (4.12), a laser ruler mounting platform (4.5), two laser rulers, and a stroke error working platform (4.11). The circular magnetic grating measuring component (4.12) is located at the connection between the lead screw pair (2.5) being measured and the integrated head frame (8), and the lead screw pair (2.5) being measured passes through the circular magnetic grating measuring component (4.12). The travel error working platform (4.11) is set on the working platform; The laser ruler mounting platform (4.5) is located at the outer edge of the bed component (1), and two laser rulers are symmetrically mounted on the laser ruler mounting platform (4.5).

5. The non-disassembly-free ball screw pair precision retention loading test device according to claim 4, characterized in that, The circular magnetic grating measuring device includes a lead screw chuck fixture (4.13), a magnetic grating adapter plate (4.14), a support unit (4.15), a reference sleeve (4.16), a cross roller bearing (4.17), a reading head connecting plate (4.18), a reading head (4.19), and a circular magnetic grating (4.20). The reference sleeve (4.16) is mounted on the integrated head frame (8), and a support unit (4.15) is mounted on one side of the reference sleeve (4.16). The cross roller bearing (4.17) is located on the end face of the integrated head frame (8) and is connected to the magnetic grid adapter plate (4.14). The circular magnetic grating (4.20) is mounted on the magnetic grating adapter plate (4.14); The reading head connecting plate (4.18) is installed inside the integrated head frame (8), and the reading head (4.19) is installed on the reading head connecting plate (4.18); the lead screw chuck fixture (4.13) and the magnetic grid adapter plate (4.14) are connected.

6. The non-disassembly-free ball screw pair precision retention loading test device according to claim 4, characterized in that, The travel error working platform (4.11) includes a movable upper plate (4.23), a reflector (4.21), a reflector mounting platform (4.22), a movable upper plate cross roller guide rail (4.24), a probe fixing block (4.30), a working platform cross roller guide rail (4.27), a probe device adjusting block (4.28), a rotating handle (4.29), and a probe mounting shaft (4.26). The movable upper plate (4.23) is mounted on the movable worktable (9); The reflector mounting platform (4.22) is fixedly mounted on the movable upper plate (4.23), and a reflector (4.19) is fixedly mounted on the reflector mounting platform (4.22). The movable upper plate (4.23) is provided on the movable upper plate cross roller guide rail (4.24), and the probe fixing block (4.30) is installed on the movable upper plate (4.23) and is slidably connected to the movable upper plate cross roller guide rail (4.24); The mobile worktable (9) is provided with a cross roller guide rail (4.27), and the mobile upper plate (4.23) slides with the mobile worktable (9) through the provided cross roller guide rail (4.27); The probe device adjustment block (4.28) is mounted on the movable upper plate (4.23), the rotating handle (4.29) is located on the bottom of the probe fixing block (4.30), and the probe fixing block (4.30) is also provided with a probe mounting shaft (4.26).

7. The non-disassembly-free ball screw pair precision retention loading test device according to claim 1, characterized in that, The friction torque measuring mechanism (5) includes a Y-shaped frame (5.2), a weighing force sensor (5.8), a friction torque measuring receiver rod (5.3), a lead screw nut to be measured (2.8), and a nut extension rod (5.7). The Y-shaped frame (5.2) is fixedly connected to the movable workbench (9), and the weighing force sensor (5.8) is installed directly below the Y-shaped frame (5.2). The tested lead screw nut (2.8) is set on the tested lead screw pair (2.5), and the tested lead screw nut (2.8) is set on the outer edge of the middle through hole of the movable worktable (9); The tested lead screw nut (2.8) is symmetrically provided with two shaft holes for the transition fit of the nut extension rod (5.7). The axis of the nut extension rod (5.7) inserted into the shaft hole is horizontal with the axis of the tested lead screw pair (2.5). The top of the Y-shaped frame (5.2) has a slot for inserting a friction torque measuring receiver rod (5.3). The axis of the friction torque measuring receiver rod (5.3) inserted into the slot is on the same horizontal plane as the axis of the lead screw pair (2.5) being measured.

8. The non-disassembly-free ball screw pair precision retention loading test device according to claim 7, characterized in that, The contact stiffness measuring mechanism (6) includes a screw tension / compression sensor (6.15), a reference plate (6.17), multiple contour blocks (6.12), a clamp plate (6.11), a screw clamp (6.9), a flange (6.16), a horizontal displacement sensor (6.18), and a vertical displacement sensor (6.19). The lead screw tension / compression sensor (6.15) is connected to one side of the lead screw nut (2.8) via an adapter plate (6.14) on one side, and the other side of the lead screw tension / compression sensor (6.15) is fixedly connected to the movable worktable (9). From the direction of the movable workbench (9) to the integrated head frame (8), a flange sleeve (6.16), a reference plate (6.17), multiple equal height blocks (6.12), a clamp plate (6.11), and a screw clamp ring (6.9) are arranged sequentially from the other side of the tested screw nut (2.8). Multiple contour blocks (6.12) are arranged around the reference disk (6.17) and the clamp disk (6.11); The lead screw clamp is disposed on the lead screw being measured, and the clamping plate is disposed on the lead screw clamp; Multiple vertical displacement sensors (6.19) are evenly distributed along the circumference of the fixture disk (6.11), and the probes of the vertical displacement sensors (6.19) are in contact with the reference disk (6.17). The horizontal displacement sensor (6.18) is mounted on the clamping plate (6.11), and the probe of the horizontal displacement sensor (6.18) is in contact with the deflection fixture (6.10) mounted on the reference plate (6.17).

9. The non-disassembly-free ball screw pair precision retention loading test device according to claim 1, characterized in that, The temperature measuring mechanism (7) includes a first temperature sensor probe (7.2), a second temperature sensor probe (7.10), and a third temperature sensor probe (7.11). The first double-rod telescopic cylinder (7.4) is installed on the side of the middle part of the integrated head frame (8). The end of the telescopic rod of the first double-rod telescopic cylinder (7.4) is connected to the first cylinder fixing plate (7.5). The first cylinder fixing plate (7.5) is connected to the second double-rod telescopic cylinder (7.6). The end of the telescopic rod of the second double-rod telescopic cylinder (7.6) is connected to a temperature sensor probe fixing plate (7.3), and a first temperature sensor probe (7.2) is provided on the temperature sensor probe fixing plate (7.3). A second cylinder fixing plate (7.8) is installed on the mobile worktable (9), and a third double-rod telescopic cylinder (7.9) is installed on the second cylinder fixing plate (7.8); a second temperature sensor probe (7.10) is provided at the end of the telescopic rod of the third double-rod telescopic cylinder (7.9). The tailstock (2.4) is provided with a third cylinder fixing plate (7.13), and a fourth double-rod telescopic cylinder (7.12) is installed on the third cylinder fixing plate (7.13). A third temperature sensor probe (7.11) is provided at the end of the fourth double-rod telescopic cylinder (7.12).

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