负重型外骨骼机器人液压阀块流道的流场分析及优化

Flow Field Analysis and Optimization for Internal Channel of Hydraulic Manifold Block in Lower Extremity Exoskeleton Robot

为了研究负重型外骨骼液压动力单元温升及噪声过大的问题,利用ANSYS Fluent软件对负重型外骨骼液压阀块内部流道主要组成部分Z型流道和交叉流道进行计算流体动力学仿真,分别设计了5组不同尺寸的仿真试验,分析不同流道尺寸下流体速度稳定性与压力损失变化情况.仿真试验表明,对于流道直径为5 mm的外骨骼动力单元液压阀块交叉流道压力损失随着进出口流道偏心距的增大而增大,流体速度在偏心距为1.25 mm时稳定性最好;Z型流道压力损失在进出口流道之间的距离为17 mm时达到最小,流体速度随着该距离的增大其稳定性上升.优化过后的样机试验表明,液压阀块最大温度下降了3.3℃,最大噪声下降了7.6 dB.

In order to deal with the excessive temperature rise and noise of the hydraulic power unit in the lower extremity exoskeleton robot,ANSYS Fluent software was used for the simulation tests of Z-channel and cross-channel,which are the main components of internal flow channel of the hydraulic manifold block.Furthermore,5 groups of simulation test with different sizes are designed to analyze how the stability of flow velocity and pressure loss change with channel dimension.The simulation test shows that when the channel diameter is 5 mm,the pressure loss of the cross-channel increases with eccentricity between the inlet and outlet;and the stability of flow velocity is the best when eccentricity is 1.25 mm.The pressure loss of Z-channel reaches the minimum when the distance between inlet and outlet is 17 mm,and the stability of fluid velocity increases with the distance.The optimized prototype test shows that the maximum temperature of the hydraulic manifold block was decreased by 3.3℃and the maximum noise was decreased by 7.6 dB.