The software PRO/E was adopted to create 3D solid model of the hydraulic excavator work device. Then established the virtual prototype after added restrictions by which the model imported to the software of ADAMS. The force curves of several main articulated points were obtained through the dynamics simulation by which the step function of the cylinder displacement, the step function of the force of the bucket tooth tip, the step function of the material gravity was caculated. The results has provided the basis for the strength analysis and structural optimization of the hydraulic excavator working device. The simulation test for the bucket arm cylinder of virtual prototype maximum digging force was accomplished by utilizing the principle of analog dynamometer. Then calculate the bucket arm cylinder maximum digging force, and the comparative analysis between the calculation results and the simulation results was completed. The research has provided the new avenue for the test of the excavator digging force.

The strong swirl turbulent flow and the movement of drops in the cyclone separator are very complex and much more random. So it is very difficult to predict the law of flow with parse means. In order to study the condition of motion of the drops inside a stream cyclone separator of the type stairmand and it′s mechanism of separation, three-dimensional numerical simulation of internal flow field of stream phase and the motion condition of drops in it were conducted by using the software fluent. The results show that the moving tracks of small drops and big drops are different, even if their original locations are the same. The effect of the flow pulse and the toted action from big drops is very marked for the small drops, so the probability of its appearance in second flow is also much, and the effect for the capability of separation is also much. therefore， the drop is more big, the separation efficiency is more high.