| This topic is based on the current status of agricultural work.Medium horsepower tractors are widely used by farmers.With the development of the national economy,the user’s focus on tractors has also quietly changed.From the requirements of simple power machinery that can only be used,it has gradually shifted to fuel economy,driving comfort,noise control,etc.Therefore,the defects of the original gearbox have gradually emerged.Its large noise,large power loss,large steering stroke,and small selection of the speed range can no longer meet the user’s requirements for this series of tractors.The life cycle requires a major upgrade.This subject further expands the performance of medium-horsepower tractors,to make them more powerful and practical.The prototype of the tractor gearbox designed and improved in this project is a 10+2 gear shifting with meshing sleeve developed by the Shandong Tractor Factory in the 1960s.According to Wuzheng Group’s "medium tractor Transmission Optimization and Upgrade Project",the original gearbox was designed and improved.The main design improvement points were 12 gears changing to 20 gears,and the gear shifting method was upgraded to synchronizer,and the driver’s driving experience has been improved,Both the smoothness of the transmission and its efficiency have been improved.The core design improvement of this subject is not only through the rational selection of synchronizers,but also the use of synchronizer shift conditions to reduce the shift stroke,reduce the operating force,and optimize the gearbox shifting effect.To design and improve the gearbox,firstly establish a parameterized model to determine the layout through UG,and build a three-dimensional simulation model of the gearbox.The model tree diagram,constraints and kinematics calculation model are established in KISSsys software,and then they are preliminarily parameterized in KISSsoft.The parametric simulation design can be more conveniently implemented with the help of KISSsys simulation calculation module.Check and optimize the design of gears,shafts,bearings and other models with KISSsoft.The calculation and calculation of the box are performed through Hypermesh,and the design optimization is performed at the same time,and finally the bearing capacity and service life of the entire drive train are improved.Finally,through gearbox reliability tests,the weak links of the gearbox are further verified,and the optimized design is performed to meet the reliability requirements of the end users. |
