联合收获机传动带稳态温度场预测与试验

Prediction and Experiment on Steady Temperature Field of Combine Drive Belt

传动带是联合收获机的关键传动部件,在联合收获机高强度作业过程中会出现因温度升高加剧橡胶老化、表面硬化及磨损开裂等现象。针对传动带稳态温度场分布计算问题,提出了一种基于动力学模型和有限元仿真计算的传动带稳态温度场预测方法。首先,在AVL Excite TD软件中通过设置带轮的物性参数、带的动态特性参数、张紧机构摩擦和扭转参数、驱动和负载参数,构建了传动带温升热源计算模型。其次,通过分析传动带热平衡方程、确定热流分配系数和对流换热条件,建立其二维稳态温度场有限元预测模型。再次,基于联合收获机CAN总线,开发了传动带工况采集系统。最后,以GM80型小麦收获机发动机动力输出轴与后中间轴之间的联组带为对象,开展了传动带稳态温度场预测田间试验。试验结果表明:当主动轮平均转速2244 r/min、从动轮平均负载338 N·m时,实测稳态温度为42.55℃,仿真稳态温度为41.7℃,稳态误差为1.97%;当驱动轮平均转速2244 r/min、从动轮平均负载382 N·m时,实测稳态温度为45.95℃,仿真稳态温度为45.2℃,稳态误差为1.63%。两次试验的稳态误差均小于2%,验证了联合收获机传动带稳态温度场预测方法的可行性与准确性。

Belt is the key transmission component of combine,which will lead to rubber aging,surface hardening and wear cracking due to temperature rise in the process of high strength operation.Focused on calculation of temperature field of belt,a prediction method of steady-state temperature field of transmission belt based on dynamic model and finite element simulation was proposed.Firstly,calculation model of temperature rise and heat source of transmission belt was established by setting physical parameters of the pulley,dynamic characteristic parameters of belt,friction and torsion parameters of tension mechanism,driving and load parameters in AVL Excite TD software.Secondly,finite element prediction model of two-dimensional steady-state temperature field was established by analyzing heat balance equation of belt,calculating heat flow distribution coefficient and heat transfer coefficient.Thirdly,belt working condition acquisition system was developed based on CAN bus of combine.Finally,steady temperature field of a certain V-belts of wheat harvester was studied.The experiment results showed that measured steady-state temperature was 42.55℃and simulated steady-state temperature was 41.7℃under the working conditions of average speed of driving wheel of 2244 r/min and average load of driven wheel of 338 N·m.The steady-state error was 1.97%.Measured steady-state temperature was 45.95℃and simulated steady-state temperature was 45.2℃under the working conditions of average speed of driving wheel of 2244 r/min and average load of driven wheel of 382 N·m.The steady-state error was 1.97%.Steady-state error of the two tests was less than 2%,which verified the feasibility and accuracy of the prediction method for the steady-state temperature field of the combine drive belt.