| Modern agricultural equipment is an important technical guarantee for realizing agricultural modernization in China.The technical level of agricultural equipment determines the process of agricultural modernization and industry competitiveness.Most tractors on the market now use a single rear power take-off,and the suspended implements have fewer functions.To this end,this paper takes a certain type of tractor as the research object,and designs and studies the mechanical structure part and control part of the power output device.Based on the traditional power output structure of the tractor,a device with a middle and rear power output shaft is designed,and the torque transmission principle and influencing factors of the multi-plate clutch are analyzed.control.The details are as follows:(1)Determine the technical indicators of key components of the power output device and the basis for determination.It mainly includes transmission gear,transmission shaft,bearing,power output shaft,clutch selection and device housing.Based on the UG three-dimensional software,the parts were solid modeled,the overall layout in space was analyzed,and the feasibility of the power output device shell structure was verified.(2)Study the coupling principle and influencing factors of the multi-disc clutch.The simulation results show that the torque after the multi-disc clutch is stable is 369.06 Nm,and the designed reserve torque,the error is only 1.07%,which meets the designed torque transmission performance Requirements;The factors affecting the transmission performance of the multi-plate clutch are analyzed,such as the oil pressure,the number of grooves,and the number of friction pairs.The simulation results show that the oil pressure and friction pair have a greater influence on the transmission of torque,and the number of grooves has a smaller influence on the torque combination.(3)Through the analysis of the force of the shaft in the transmission system,it is obtained that the maximum torsional stress and the maximum bending stress of the shaft are under the specified allowable stress;static analysis of the bearing is performed to replace the unreasonably designed bearing.The bearing life after replacement was increased to 4042.3 and 1819.5 hrs,and the static safety factor was increased by 3.9 times and 4.18 times.The vibration characteristics of the shell were analyzed,and the correctness of the natural frequency of the shell was verified by simulation and test comparison.Analysis of the meshing frequency of the gears shows that the meshing frequency of thegears does not coincide with the frequency interval of the shell,and the shell will not resonate;completing the static strength analysis of the shell,the maximum load received by the shell is 15.35 MPa,which is less than the shell The maximum yield strength of220MPa;and the optimization design of the shell,the optimization results show that the maximum stress of the shell decreased by 35.18%,the maximum offset decreased by78.97%,and the fatigue life of the shell increased by 66.33%.(4)Using Lab VIEW software,design the multi-plate clutch torque and speed acquisition program,and obtain the multi-plate clutch main and driven shaft power,speed and torque test data.The test results show that the minimum transmission efficiency of the multi-plate clutch is 91.94% and the maximum is 95.69%.The test report and curve obtained from the power output shaft test are analyzed,and the transmission efficiency of the power output shaft is 93.70%,and the value meets the specified The power output shaft power is not less than 85% of the engine power requirements. |
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