Design Of Dynamic Test System For Wear Life Test Of Plastic Gear

Compared with metal gears,polymer composite gears have unique advantages:low cost,light weight,high efficiency,low noise,no need for external lubrication and so on.At present,although there are some national standards and commercial design methods in the design process of polymer composite gear.However,almost no standards and design methods have been verified by practice.In practice,it is found that these standards and design methods differ greatly from the experimental results,because the formulation of these standards and design methods originated from the design practice of metal gears.Therefore,the dynamic testing system of the special friction and wear test-bed for plastic gears is developed,which provides theoretical basis and experimental data for further research on the design and manufacture of non-metallic gears.The friction and wear characteristics of plastic gear meshing transmission are studied.Based on Archard friction and wear model,the wear model of plastic gear with viscoelastic characteristics is established.Based on Hertzian contact theory,the contact forms between tooth surfaces are analyzed,and the friction calculation model between gear pairs is established.Based on the thermodynamic and dynamic analysis of the meshing transmission process of plastic gears,the thermo-mechanical coupling model is established.The friction heat is simulated by finite element analysis software.The results show that the peak temperature occurs at the meshing point and the meshing point of a single tooth,and the temperature is uniformly distributed along the width direction of the tooth.Therefore,the meshing point or the meshing point is selected as the temperature measurement point in the experiment.The main factors affecting the transient temperature of the meshing interface of plastic gears are analyzed and studied.The results show that with the increase of friction coefficient and load torque,the temperature field of the gears changes significantly,which is the main factor affecting the temperature field.According to the indirect testing principle of“discontinuous phase method”,the objective function theory model of the plastic gear wear life test-bed is established.Combining with the dynamic loading characteristics of the plastic gear wear life test-bed,the conversion model of the pivot fast deflection angle with friction factor and wear quantity is concluded.Based on the characteristics ofθ,self-compensating force F_c and external load G,the measurement and control system is designed.Pre-amplifier circuit,second-order active band-pass filter circuit and other signal processing,amplification and conversion circuits;VB language was used to write the wear depth time program module and multi-channel acquisition module program.Based on the general scheme of the testing system,the hardware structure of the data acquisition and processing system based on the data acquisition card as the control core is determined,and the components of the testing system are reasonably selected.With the help of the software development platform of LABVIEW,the application program of target letter acquisition is developed,and the interactive interface of the software system is designed.The installation of the measuring and controlling system is completed on the self-made plastic gear wear life test bench.Based on the test system of the test machine,the friction and wear experiments of the typical polyphenylene sulfide,poly ether ether ketone and polyimide gears in the special engineering plastics were carried out on the wear life test bench of the plastic gears.The main factors affecting the experimental errors are analyzed and analyzed.The regression analysis of the experimental errors is carried out,and the correction method of the experimental errors of the plastic gear wear life test-bed is established.