Objective To design a hydraulic driven disc harrow, and to use it under the working conditions of the middle-lower Yangtze plain with sticky and sealing soil, large amount of rice straws and fluctuating soil moisture content.
Method The structure and operation parameters of the disc harrow were analyzed and the hydraulic driven system was designed. The rotary speed ranges of the hydraulic motor were determined according to the forward speed of the system. The motion trajectory of the notched disc was analyzed and the critical angle of the disc was determined. The process that the disc cutting the soil was analyzed using the finite element simulation method based on ANSYS/LS-DYNA.
Result The rotary speed of hydraulic motor ranged from 60 to 168 r·min–1. The critical angle of the disc was 23°. The simulation results showed that the resistance of soil cutting by the disc changed periodically, increased gradually as soil depth increased and then became stable. Compared with a negative disc, the hydraulic driven notched disc could rotate more soil and its tillage depth was more stable. Field experiment showed that the tillage depth for the hydraulic driven notched disc was 85–120 mm and the coefficient of variation for stability in tillage depth was 9.6%.
Conclusion The hydraulic driven disc harrow meets the design requirements.
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