Drive speed reducer is an ideal driving component for mining machinery, marine machinery, engineering machinery and construction machinery. It is provided with two or three stage planetary gear drive, which has features of stable torque driving, compact structure, less maintenance, long working life. The product has reached the advanced world level in the same period and in the same kind of products. Series is made up of five models covering the requirements of truck mixers in the 3 through 16 m3 mixing range.