Design And Analysis For Load Sharing Device Of Tower Crane Slewing System

In the parts of the tower crane,tower crane rotary table is a very important part.Rotary table can drive the entire upper slewing motion,and the slewing speed is relatively low speed,low-speed overloading,in practice,but also can withstand frequent positive and negative brake.Therefore,during slewing motion,the gear of the slewing mechanism bears greater inertia force and dynamic load,which is more likely to cause the fatigue failure of meshing teeth;and then slewing bearing radial force and overturning moment are unevenly distributed,which will cause the tower vibration instability caused by vibration resulting in damage to rotary reducer,and even cause the twist deformation of the tower body.In this paper,according to the characteristics of planetary gear transmission which uses multiple planetary wheels sharing the load,a design scheme of tower crane rotary system of load sharing is proposed,and according to the scheme of the load,an equalizing device of rotary system is designed.UG software is used to establish the three-dimensional models of two platforms,and the ADAMS dynamics simulation software is used to do dynamic analysis of the rotary load equalizing device and the original single rotary mechanism respectively and make comparison.The uniformly loaded turntable is compared with the single rotary turntable based on the main factors of overturning moment,rotation speed fluctuation,and rotary acceleration of the slewing bearing.According to the actual structure combined with the rotary tower crane,the virtual prototype dynamic model of tower crane slewing system is effectively built to study the load balancing device of gear by calculating the load and the load sharing coefficient,so as to understand if the equilibrating load device is feasible.The finite element model of the 3D model dividing grid of the turntable is established by Hyper Mesh,and the dynamic characteristics of the whole turntable system are analyzed by introducing the data into the ANSYS software,and the first six natural frequencies and mode shapes are obtained.Through the analysis of the results,the rotary table presented in this paper is compared with the radial force loading device of single rotary turntable producing smaller rotary support and overturning moment change is greatly reduced that can improve the bearing capacity and the ability to work of the tower crane.