Design and testing of a liftable chassis for rice harvester

During the operation of the rice combine harvester， the fuselage tilts due to the tilt and unevenness of the ground affect its maneuverability and operational reliability. Aiming at the problem of leveling due to the tilt of the field surface， this research developed an innovative dual-parallelogram chassis lifting mechanism for rice harvesters designed a hydraulic system to adjust the chassis height by extending the cylinder. Using Adams simulation software， a detailed model of the lifting chassis was constructed to analyze its performance， revealing a direct correlation between the hydraulic cylinder extension and chassis elevation. Notably， the mechanism could achieve leveling on slopes with inclination angles of up to 7.5°. Comprehensive evaluations of the liftable chassis system were conducted under both static and dynamic conditions. In the static tests， the system exhibited the capacity for comprehensive or unilateral auto-leveling contingent upon the tilt， with leveling times and angular variations confined to 3.6 s and ±0.4°， respectively. In dynamic tests conducted on sloped fields and paddy soils， the system reduced post-leveling mean tilt angles and standard deviations remained below 1.2° and 0.6°， respectively. These results demonstrated a substantial improvement in the stability and reliability of the chassis during operations. This research provides valuable insights into the design and optimization of automatic leveling mechanisms and structural innovations for harvester chassis.