| As a common linear motion mechanism,sliding screw pair has the advantages of simple structure,stable transmission ratio,high precision displacement and large external force output.It can also realize self-locking function,so it is widely used in the field of linear heavy load transmission.However,the traditional sliding screw pair of metal materials has some problems such as high friction coefficient,low mechanical efficiency,large vibration and easy wear,which restrict the development and application of spiral drive.The relevant testing technology of the linear transmission device of sliding screw pair is also backward,and the test items are relatively single.As the linear transmission device tends to high speed and high efficiency,higher requirements are put forward for its motion precision,transmission efficiency,structural stability,service life and other performance indicators.To solve this problem,the research team proposed a new composite sliding screw pair linear transmission device composed of self-lubricating composite steel back/carbon fiber liner nut,which proposed a new solution for the development of high-efficiency heavy-duty screw transmission.But for this new type of composite sliding screw pair of linear actuator design,manufacture and testing of all have no ready-made method,so this article on the basis of research on composite sliding screw pair application composites sliding screw pair of linear actuator prototype,and based on the requirement of test research and development testing system for the comprehensive performance of linear actuator,after conducting the related test.This paper mainly shows the following aspects:(1)Development and application of composite sliding screw pair linear transmission device prototype: according to the design requirements,the principle,structure and transmission characteristics of sliding screw drive are analyzed,and the appropriate screw nut pair is designed,and the strength and stability are checked.According to the requirements of transmission power,the deceleration ratio and the torque and speed parameters of the servo motor were determined.Based on this,a prototype of linear transmission device with composite sliding screw pair was developed.Its main technical parameters are axial bearing capacity of 50 k N and stroke of 300 mm.The motion control system of the linear transmission device chooses the motion control mode of "industrial computer + motion control card +PLC",which is suitable for the control of linear transmission unit with different requirements.(2)Develop composite linear transmission device performance test module: the hydraulic cylinder is selected to load the linear transmission device for external force,the hydraulic cylinder is docked with the linear transmission device,the linear transmission device is used to drive the hydraulic cylinder in the test,and the loading force of the linear transmission device is set by changing the pressure of the hydraulic cylinder.The data acquisition part of the test system takes the high-speed data acquisition card and the PLC analog input module as the acquisition collector.According to the design scheme of the test system,the hardware selection,circuit connection and the underlying program design are completed.Visual Studio2008 and Lab VIEW 2018 are selected as software development platforms to design an intuitive and easy-to-operate man-machine interface with functions such as motion control,status monitoring,data analysis and automatic storage.(3)structures,debug the system,the sliding screw pair of straight line transmission device of the composites performance testing experiments and compared with traditional metal sliding screw pair,according to the results of optimization test system and linear drive control system: to carry out the positioning accuracy,backlash,friction coefficient,mechanical efficiency,vibration and life such as linear actuator comprehensive performance test project;The test experiment has improved the problem that the indirect current test method is quick to measure the torque but the accuracy is not enough.Through the comparison and research of the results of the indirect current test method and the direct test method,the multiple regression model is adopted to make the indirect test method greatly improve the testing accuracy and expand its application range while maintaining the advantages of convenience and speed.The positioning accuracy can be controlled by error compensation according to the test results of the testing system,so as to further improve the transmission accuracy and make the device adapt to the working situation with higher motion accuracy requirements.The results show that:1)The comprehensive performance test system of the linear transmission device runs stably,and the test results are accurate and reliable,which can meet the test requirements of composite sliding screw pairs,and can also be used for performance test research of other screw pairs.2)Based on the linear transmission device of composite sliding screw pair developed by the research group,the test results show that the transmission accuracy can be controlled below100μm,which can meet the accuracy requirements of press and electric cylinder,etc.If necessary,error compensation control can be added to improve the transmission accuracy.The mechanical efficiency of the new composite sliding screw pair is 7% higher than that of the traditional sliding screw pair.Under the same working conditions,the vibration amplitude is about 19%～27% lower than that of the traditional sliding screw pair.It can operate continuously for about 93.7 working days under the common load of 8h per day.The actual working conditions of the performance is more superior.The test results confirm that the linear transmission device of the composite sliding screw pair has excellent characteristics such as high mechanical efficiency and smooth operation,and provide data support for the further research of the composite sliding screw pair. |
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