Pressure Calculation And Stiffness Analysis Of Jacketed Roller Slewing Bearing Of Large Crane

With the rapid development of national economy,the demand of marine exploit is also become strong,Large-scale floating crane as an important marine engineering equipment,is widely used in marine oil and gas development,salvage leasing,hydraulic construction and other fields.Rotary bearing as one of the key structure of the crane,its design is directly related to the use of the whole machine’s performance and safety.Roller jacketed slewing bearing is widely used in large floating cranes because of its compact structure,easy installation and maintenance,low center of gravity,high bearing capacity and a series of advantages.However,the slewing bearing is carried uneven load because of no balance device,it belongs to the typical high-order statically indeterminate structure,has many wheel-rail contacts,wheel pressure calculation is complex.In this paper,a 700 t large crane roller jacketed slewing ring is used as the research object,to establish the mechanical model of the slewing bearing structure an,calculate the roller wheel pressure and distribution law,then use the finite element software ANSYS Workbench as a tool to verify the reliability of mechanical model.According to the proposed formula of the wheel pressure,the influence of the stiffness factor on the wheel pressure distribution in the analysis structure is analyzed,to propose optimization so that the wheel load more balanced and the bearing capacity of the slewing bearing structure is improved,the main work from the following points:(1)According to the structural characteristics of the rigid support frame of the slewing bearing structure,the balance equation is established to simplify the load on the crane into a multi-point concentrated force applied to the slewing bearing beam,take part of the structure of the ring bearing beam,and the roller,smoke pad,track,etc.to establish a simplified model of mechanics,to solve the maximum load to the wheel on the wheel of the wheel pressure values,finishing concentrated force after the maximum roller wheel pressure value,and draw the wheel pressure distribution curve,.(2)A three-dimensional model of the slewing bearing structure is created and imported into the Workbench.Set the contact type in the structural assembly,mesh and add the boundary conditions to solve and extract the rotation force of the wheel,that is,the corresponding wheel pressure.Statistics of all wheel pressure as the results of the finite element method are compared with the calculated results of the mechanical model,and then analyze the similarities and differences.(3)Under the premise of reliable reliability model,the influence of each stiffness factor on the final wheel pressure solution is analyzed according to the wheel pressure calculation matrix,then the optimal reference is given,select the appropriate structural parameters to reduce the maximum wheel pressure and balance the wheel loaded.In this research,the load on the crane is simplified to a number of concentrated forces applied to the slewing bearing structure,the mechanical model of the local structure is established,to solve the wheel pressure.This method can be used to calculate the wheel pressure more accurately by the finite element method verified,which can reflect the influence of the stiffness factor on the load of the roller.It provides the theoretical basis for the optimization of the wheel pressure and provides reference for the research of the roller jacketed slewing ring.