Dynamic Analysis And Experimental Study For The Differential Steering System Of The Tracked Combine Harvester

The rice as one of the major food crops in China, its harvest way is mostly adopts caterpillar combine harvester; With the large promotion of super rice, rice yield increase rapidly, and the requirement of efficient harvest from users, the large feeding amount combine harvester gradually becomes the mainstream. Now the weight of large feeding amount crawler combine harvester is more and more bigger, the track is wider, and grounding length is larger, thus in the rice field, the traditional way of unilateral brake makes steering resistance increase sharply, steering ability is greatly reduced, even leads to the engine flameout, which causes steering more difficult, and becomes a large bottleneck for the large amount feeding crawler combine development.In this paper, the performance analysis for a new type of differential steering system developed by this team is conducted. Combining with Pro/E, Hypermesh pretreatment and Abaqus post-processing software, dynamic simulation was carried out on the gear meshing transmission, compared with the theoretical calculation results, the transmission system is reliable. Further, combining with Pro/E and RecurDyn, walking performance simulation was carried out, and the validated field experiment and research were carried out, aimed at the differential steering system into the actual production. The research includes:1、Based on basic formation principle of the involute tooth profile, precision parameterized modeling of planet gear and half-shaft gear are established. Then the finite element mesh model meeting the requirements of meshing and calculation accuracy is built, after that, the model materials, contact, step and boundary conditions are added to meet the requirements of subsequent calculations. Dynamic meshing and contact stress analysis are conducted. At the differential steering working conditions, the gear meshing process analysis, including the impact of the meshing gear pair in the situation, the tooth root bending stress and contact stress of the size, distribution and the analysis of the planetary gear strength is carried out.2、The multi-body dynamics model is established based on RecurDyn. Including differential steering system and inclined tangential-longitudinal flow experimental platform accurate models, left and right two crawler sub-module.The constraint is established in according to the movement relationship, the input parameters are set up according to the actual working principle. Based on the different working condition of the harvester, the value of different input parameters are set up, and the kinematic simulation is conducted. The analysis for the performance of the vehicle in the steering process, including minimum steering radius, steering angular velocity, consumed power is carried out.3、The manufacture and assembly of the inclined tangential-longitudinal flow experimental platform are conducted, the electro-hydraulic control system of the steering system is improved, and the test scheme, sensor type and data acquisition system are confirmed, and the performance experimental platform is obtained. The experimental study on the steering performance at different conditions is carried out, including steering radius, steering angular velocity and consumed power, and the further analysis result of consumed power influenced by speed, weight of the whole machine and steering radius is obtained.