The characteristics of NGW planetary gear sets widely used in WTGs are introduced.With the design of pitch reducer for 1.5 MW WTGs

some of the key design principles and general experienced conclusions for the important and difficult points of multi-stage planetary gear transmission are given.Gear tooth strength of the weak stage is analyzed and the tooth face shape is optimized by the application of virtual prototyping tools Romax Designer.By the use of uniform load mechanism

the efficiency of the multi-stage planetary gear transmission is improved.Furthermore

the reasonability of design is proved by the prototype testing.