Abstract: A new hydraulic face-shovel excavator is proposed and its working device is a complex multi-loops coupling mechanism. The degrees of freedom of the working device are analyzed by using the modified Grübler-Kutzbach criterion. The result shows that the degrees of freedom of the working device are two translations and one rotation on a plane, which can meet the requirements of face-shovel excavator. Based on the loop algebra theory, a universal mechanical kinematics analyses black diagram is established, with which the kinematics of the mechanism is investigated. The workspace of the hydraulic face-shovel excavator is derived by the analysis of forward kinematics. The analyzed result shows the workspace is optimal when the angle between the shovel and the ground is 30°-50°, which meets the operation demand of level mining of face-shovel excavators. The velocity is analyzed by using the method of black diagram, the Jacobian matrix of input velocity and output kinematics are obtained. Finally, five numerical examples are given to verify the above analysis. Comparative analysis of the results shows that the method is reliable. The research result will lay the foundation for the application of the mechanism.

Key words: face-shovel excavator;degrees of freedom;kinematics analysis;workspace;Jacobian matrix