Study and Application of Gear Micro Modification of Electric Drive System

The gear whine in the electric drive system of an electric vehicle is important and remains a challenge in developing novel electric vehicles. A gearbox dynamic model is established, and the effects of modification parameters on the sound pressure level, transmission error, and contact stress of the gear pair are introduced to reduce the gear whine. A multi-objective optimization study of four modification variables under multiple torque conditions is carried out by using transmission error and maximum contact stress as the objective functions. The eclectic programming method is imported to solve the convergence problem of multi-objective optimization. The influence of modification variables on objective functions is studied by establishing an approximate model of the optimal Latin hypercube design. Results show that the application of the multi-objective optimization method combined with the eclectic planning method for the micro modification of the gear can reduce the transmission error of multi-torque conditions, effectively reducing the gear whine noise in multiple torque conditions and improving the contact of the tooth surface.