| Due to the type and structure of the driving system and the use of the crane,the bridge crane runs at a horizontal skew on the track,which produces a skewing load,increases the running resistance and impact of the crane,and then reduces the running performance of the crane.Generally,the frequency of horizontal skewing load changes with the change of crane operation,and the load is generally considered to be accidental.In some cases,it is necessary to determine whether the lateral force is accidental load or conventional load according to its frequency.Under the action of the skewing force,the wheel guide element contacts with the track,causing friction and rail gnawing.The friction between the wheel and the rail causes abrasion,and this abrasion greatly reduces the life of the wheel and the rail.Specially,when the wheel is guided by the rim,the rail gnawing accelerates the abrasion of the rim,causing the wheel rim to be damaged earlier than the wheel tread,and the wheel is prematurely scrapped.Therefore,when the running crane is subjected to the skewing force,there is a major security risk.This paper analyzes the horizontal skewing force generated by skewing operation of the crane,and provides theoretical support for the hidden dangers of skewing operation.According to the wear degree of the wheel caused by the skewing force,the wheel life is predicted.The main contents of this paper are as follows:(1)This article introduces the types of crane wheels and rails,and then summarizes the types of wheel wear.It is concluded that the wheel wear life is mainly determined by the wheel flange wear under the action of skewing force.In view of the difference between the rail type of crane and the rail type of transportation in terms of large wheel pressure,low speed,straight-line operation and deviation correction,this paper analyzes and summarizes the causes of the horizontal deflection lateral force caused by rail gnawing from the defects in the manufacturing and installation quality of crane wheel and rail,the transmission system and the ratio of span to track width.The harm of side force to crane and workshop is pointed out.(2)According to the different operating conditions of the crane,the wheel speed and the force of the driving wheel and the driven wheel when they are skewed are analyzed.Furthermore,the influence of the skewing force when the driving wheel has a tapered tread and an error in diameter is analyzed.This paper makes a theoretical analysis of the skew operation of the centralized driving bridge crane under the lateral force,the skew operation of the separately driven bridge crane under the lateral force,the skew operation of the two wheels on the diagonal of the crane under the lateral force and the skew operation of the two wheels on the outermost end of the end beam of the crane under the lateral force,and the calculation formula of the lateral force under each working condition are derived and compared.(3)In this paper,the professional three-dimensional modeling software Solid Works is used to create the bridge crane model.The finite element analysis software ANSYS is used to carry out the static finite element analysis and generate the MNF file.Then the MNF file is imported into the mechanical system dynamics analysis software ADAMS to carry out the rigid flexible alternation,and then carry out the dynamic analysis of the horizontal deflection and lateral force of the bridge crane under different working conditions.(4)Based on Hertz theory and Kalker linear theory,this paper analyzes the rolling contact of crane wheels when they are running on rails.This article introduces the method of predicting the fatigue life of wheel tread and the calculation method of rim wear.Then according to the obtained skewing force of the crane,it is substituted into the Archard wear model,the wheel tread wear is calculated,and the wheel life is predicted by the wheel scrap standard. |
