Abstract:In order to solve the shearing damage caused by the track combine harvester continuous steering in the field, increasing the steering flexibility of vehicle, and improving operation efficiency, the driving performance simulation test of a pivot steering mechanism at the flat hard pavement and heavy clay was conducted. In the test, the multibody dynamics model of the combine harvester was established in RecurDyn software, and the movement state was obtained, including steering angular velocity, steering angular acceleration, steering radius and output torque. On this basis, the new type pivot steering mechanism and the walking performance test harvester were trialproduced, and a large number of experiments were carried out. Test results show that, under the same steering mode condition, the differential steering output torque in paddy field is maximum, up to 5668.2N·m, much larger than that at the concrete floor, which is 2268.2N·m, at the same time, the differential steering output torque is the biggest of the three steering modes. As the rotate speed of the driving wheel is 75r/min, the angular velocity at the concrete floor is 0.610rad/s, and that of the paddy field is 0.592rad/s, which are improved by 87.7% and 88.5% separately; the minimum steering radius in the paddy field is 0.098m, and that of the concrete floor is 0.082m, which decrese the steering occupied area significately. The proposed differential steering mechanism improves the walking performance of the combine harvester greatly.