Structure Optimum Of The Rib Of Tapered Roller Bearing Of Reducer Of Heavy Truck Rear Axle

The reducer of rear axle of heavy truck is a part of Heavy truck transmission system,whereas,the tapered roller bearing(TRB)used by reducer is regarded as an important part to ensure reducer operate well.TRB 32013 is selected by a reducer of rear axle of heavy truck.The rib of TRB will appear axial fracture by accident because TRB runs in severe working condition such as: heavy load,large impact load,radial and axial load.It leads to the reduction of life and reliability of TRB.Therefore,it is necessary to analyze the fracture phenomenon of rib of TRB,to find the reasons and solutions,to ensure TRB can operate in safe and reliable conditions.The contents of this paper include the following aspects:(1)The reason which causes the rib of TRB 32013 fracture failure is analyzed.The structure of TRB 32013 and the stress state of single bearing are studied.According to the bearing loading forms and the relevant parameters of reducer of rear axle of heavy truck in actual conditions,the load of bearing is calculated.The results show that the reason of fracture failure is bearing overload running.So the basic reason of fracture failure is bearing overload.(2)The method of improving the rib strength is analyzed.According to studying the intensity of the rib of the bearing,the method through increasing the rib thickness to reduce the rib stress is put forward.Stress values which correspond to increasing thickness of rib are calculated by classical mechanics and the finite element software respectively.The results show that when the rib thickness increases to a = 5.49,the rib intensity can meet the operating requirements.(3)Applying finite element method,the stress condition of bearing large block is analyzed.Through the ANSYS software to the rated load and overload bearing model by analysis of load simulation,different loads were calculated at the side of the big gear contact stress,the stress and deformation degree is higher than the rated load state when bearing overload.Through the finite element model of different rib thickness analysis,it is found that with the increase of rib thickness,rib of stress willchange gradually decreased,and then confirms the larger rib thickness increase can reduce the rib stress by feasibility.Then,based on the influence of structure of large rib and rib stress on rib strength,the optimized rib size is determined and the formula of calculating range of flange force point and edge and the inner raceway angle is deduced,and the edge structure size after the optimization of large gear is given.(4)The fatigue life of the optimized rib of TRB 32013 is verified.The reasonable processing technology and testing requirements are formulated according to optimized bearing structure size chart.Through using the machine of the fatigue life to verify the optimized bearing,it is found that when the rib thickness is a=5.49 ± 0.01,ψ= 89°27’ ~ 89°38’,bearing can’t appear fracture failure,it can meet the operating requirements.