| The anti-radiation hydraulic excavator is one of the badly-needed engineering mechanical equipments in the operation of nuclear facility decommissioning and nuclear emergency rescue work. Slewing system is one of the important subsystems of the anti-radiation hydraulic excavator. Due to the increasement of the upper frame mass of the anti-radiation hydraulic excavator and the deviation of the barycenter, it causes large moment of inertia,large inertia and large impact load during the operation of the slewing system.If the design of slewing system is not reasonable, it will cause large vibration and high noise, and even the gear teeth of slewing gear will be broken off.Therefore, a research was conducted on dynamic characteristics of the anti-radiation hydraulic's slewing system via using the method of theoretical analysis and simulation, it has important theoretical significance and practical value in engineering for increasing the reliability of slewing gear, reducing the slewing hydraulic shock and improving the stability of the slewing, and it could provide a theoretical reference for the design and optimization of the slewing system. This thesis is carried on as the following aspects:1. This thesis theoretically analyzes the slewing system of anti-radiationhydraulic excavator, then deduces the transfer function of valve controlled hydraulic motor, and summarizes the calculation formula of the movement characteristic of the slewing platform.2. A simulation model of anti-radiation hydraulic excavator's slewing hydraulic system is built based on AMESim. This thesis makes an analysis to the influence of slewing platform's moment of inertia, hydraulic oil viscosity,slewing hydraulic motor's displacement and slewing overflow valve cracking pressure on the startup dynamic characteristics of slewing hydraulic excavator.3. The dynamic model of slewing gear is built via using torsional vibration model of gear pair. The dynamic model of slewing gear is established based on ADAMS. The simulation results of rotating speed of gear ring, meshing force and the frequency of meshing force are much same as the theoretical calculation value, thus, the accuracy and reliability of the model are verified. The thesis also makes an analysis to the influence law of slewing drive speed and load torque on meshing force based on the simulation model.4. By analyzing the static response of slewing gear ring under the maximum meshing force based on ANSYS Workbench, and checking the strength of gear ring's teeth via the maximum equivalent stress(Von-Mises Strsss), a conclusion is reached that the slewing gear ring can meet the strength requirements. |
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