| The technology employed in the wheel loader transmission is an important factor restricting domestic wheel loader industry development. How to make exclusive breakthroughs on transmission used in wheel loaders is always the research field where lots of transmission technicians work hard.This essay is based on the real problems found in ZL30G And what we need to do is to develop a hydroelectric/hydrodynamic controlled power-shift countershaft transmission to replace the traditional one without changing other components. This provides solutions to the need of wheel loader generation renewal while at the same time can still meet old products users'demands on spare parts. After lots of tests on this transmission, it has met ZL30G technical requirements. Detailed research is as follows,(1) Research and development on ZL30G transmission parameters and structure. Transmission installation plan was finalized based on the design, giving full consideration to the problems which may arise during assembly, repair and maintenance. Through the analysis on the transmission gear number and speed ratio and the structures of several kinds of imported countershaft transmissions, the 3-DOF (3 degrees of freedom) F3/R3 power-shift countershaft transmission plan was adopted, taking ZL30G performance demand into consideration.(2) Transmission performance matching in ZL30G and the design and research on the load spectrum and clutch of the power-shift transmission. Details are as follows, match the ZL30G transmission system with new transmission using the matching software and adjust the torque offset to meet ZL30G performance requirements through the analysis on the transmission system tractive performance. Use the load cycle to better calculate the performance and the service life of the transmission components and the parameter modeling and analysis on the whole transmission system for optimization. The load cycle for ZL30G transmission calculation is defined according to the operation conditions. Paper-based friction disc with compound oil flute is adopted through analysis on the design requirements and technical features of the power-shift clutch and the friction material impact on the clutch performance. (such factors as temperature, heat-dissipation, oil flute which may have an impact on the friction material performance are also taken into consideration). The torque capacities and reserve factors for 5 clutches, the surface pressure and the master clutch disk relative rotation speed can be calculated according to the clutch bearing capacity.(3) We can get the cooling oil amount needed for the transmission rotatory parts through lubrication analysis, simulation and test on the transmission assembly. In this essay, first, I make a theoretical analysis on the features for the transmission rotatory parts working in tough operation conditions, and then I can get the minimum cooling oil amount needed so that the burning of the bearing and the deflection of the friction disk caused by over-heating for the lack of lubricants can be avoided during bearing and clutch friction disk working, which can ensure the transmission normal function.Establish the dynamic simulation model of the transmission assembly by the AMESim software, Setting the model parameter according to the total cooling oil mass as well as the min. flow value of all revolving parts, obtaining all lubrication holes diameter and flow value with oil mass optimization on all revolving parts, then take the transmission lubrication system as the testing stand to implement the static test for simulation results. Distribute the clutch friction plates and bearing lubrication oil by testing the actual data collection. Adjust the size of lubrication hole by modifying the 4 plans. Confirm the lubrication oil mass of the bearings and friction plates to get the proper data, as well as analysis the error source of the result to ensure the cooling and lubrication of the transmission assembly.(4) The bench performance and1000hrs fatigue test of accelerated durability test is implemented on the Labview platform of speed range test. It is to implement tests of transmission on idle power loss, operating oil pressure, gear shifting process, driving efficiency, temperature rise and assembly accelerated durability fatigue. Based on the bench test data, we examine the main technical parameter, index of reliability and comprehensive properties, analysis and compare the testing result with theoretical calculations to draw the matched, correct, designed driving shift transmission assembly, as well as the conclusion which matches the axle and meets the traction and speed requirements of ZL30 wheel loader.(5) The ZL30 wheel loader transmission meets the design requirements after testing on test stand and assembly. The customer of heavy duty will obtain bigger values from its operation.The design of ZL30 wheel loader transmission has its economic and social value. It's more suitable to the drive train of ZL30 wheel loader and improves its traction and rideability performance.
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