| With the progress of science and technology and the improvement of agricultural machinery performance requirements,users of small and medium horsepower tractor reliability and comfort requirements are also increasing.The synchronizer shifting technology is widely used in the automobile and the large horsepower tractor,which improves the operation comfort and service life of the machine.The technology applied to small horsepower tractor is still in its infancy.The related structural layout and size parameters also need to be re designed and verified.In this paper,the performance requirements of the tractor in the middle power synchro are studied.The design arrangement of 16+8 gear transmission system is emphasized,which provides a method for the design of horse-power transmission system in the industry.Through market analysis,customer demand research and benchmarking vehicle research.The parameters of the tractor are calculated by using the tractor design manual and empirical formula.The product design positioning and basic performance indexes are clarified.KISSSOFT software is used to establish the 16+8 gear system model,analyze and optimize the gear arrangement,determine the transmission structure and transmission system design parameters,the results show that the designed gear arrangement is reasonable.In order to solve the problem of insufficient space utilization of the traditional tractor gearbox structure,the cylindrical box structure is adopted.The advantages of triaxial structure arrangement and drum box structure are studied.The results show that the structure strength of the box can meet the requirement of 16+8 gear arrangement,It is stronger than the same horsepower tractor housing in the industry.It is difficult to determine the key load boundary conditions of the box strength under different working conditions.ABAQUS software is used to analyze the structural strength of gearbox housing,and the weak points and stress concentration points are found out.Through optimizing the structure design and carrying on the secondary analysis verification,the result shows that the gearbox meets the use demand.At the same time,the nonlinear contact analysis technology is used to solve the problem of oil leakage on the binding surface of tractor box,Simulate the separation clearance and contact pressure of contact surface,he position of oil leakage point in advance was studied,And adopt reasonable and effective form of bolt fixation or adjust the strength of box structure,The results show that the separation clearance is controlled within the permissible range.Aiming at the problem that the development and verification time of tractor products in the industry is too long,Use the company's existing test equipment,The durability test is carried out through the transmission system bench,The results show that the strength and life of each gear shaft and bearing in the 16+8 gear shift transmission system can meet the design requirement of 800 hours without fault. |
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