Research On Automatic Design Method Of Wind Turbine Pitch Bearing

Pitch bearing is an important part of wind power equipment,its performance affects the safety and stability of the whole fan.Compared with the common rolling bearing,the pitch bearing has the characteristics of large size,complex load,low speed,bad working environment and part of it is exposed.Therefore,the structure design of the pitch bearing is very important.But the current design methods of the pitch bearing mostly rely on the design experience or refer to the design method of the common bearing,and the design is tedious and the cycle is long.Therefore,by planning the process of pitch bearing automatic design,designing the algorithm of pitch bearing automatic design,and establishing the knowledge base of pitch bearing,the automatic design of pitch bearing is realized.Firstly,the structure and characteristics of the pitch bearing are introduced,and the load types of the pitch bearing are analyzed.Then the calculation method of the contact stress and the life of the pitch bearing are studied,and the calculation process is deduced in detail.Secondly,the traditional design method of pitch bearing is studied.The external dimensions(outer diameter of outer ring,inner diameter of inner ring and height of outer ring)of pitch bearing are determined according to the space dimension of fan and the dimension of hub blade.Then the main parameters(pitch diameter of rolling body,diameter of rolling body,number of rolling bodies and curvature radius coefficient of inner and outer ring raceway)of pitch bearing are calculated according to geometric constraints.Finally calculate other structural parameters according to the standard and calculation formula.Then,by planning the automatic design process of pitch bearing is planned;the automatic design algorithm of pitch bearing is designed;the knowledge base of pitch bearing is established.The common mathematical models of pitch bearing is stored in the knowledge base,the mathematical model of bearing is not needed establish every time and can be directly selected and called in the knowledge base.The results of each design is stored in the knowledge base and treated as historical data for subsequent data to use analysis and design.So as to achieve the automatic design of pitch bearing.Finally,according to the actual working condition of the pitch bearing,the finite element model of the pitch bearing is established.In the finite element model,the spring element is used to replace the rolling element and the beam element to replace the bolt.The finite element model is used to analyze and calculate the pitch bearing designed by the traditional design method and the automatic design method respectively.The structural parameters of the pitch bearing designed by the two design methods are compared with the finite element verification results.The research results are as follows: in this paper,by planning the automatic design process of pitch bearing,designing the automatic design algorithm of pitch bearing,establishing the knowledge base of pitch bearing,realizing the automatic design of pitch bearing.Finally,the bearing designed by the automatic design method is compared with the bearing designed by the traditional design method,and the finite element verification analysis is carried out,the rationality and effectiveness of the automatic design method of pitch bearing are proved,which provides a new thinking for pitch bearing design.