Noise Analysis And Electromagnetic Design Of Car Sunroof Motor

The use of car sunroof has brought great convenience to people's life. However, noises are generated when the sunroof motor is running, which reduces people's drive comfort. Sunroof motor is composed of driving motor and transmission system. Because of its internal installation in automobile and special transmission chain, rigor requirements must be made for the car sunroof motor noise control and design. This study is inspired from a company's need for low-noise export sunroof motor and centers on the sunroof motor designing, system noise testing, analyzing and optimizing. The research is practically significant to the low-noise sunroof motor design and noise source test. In this thesis, P1137 Volvo car sunroof motor is chosen as the research object. The main contents of this thesis include:①Base on the elaboration of the basic structure, operating principle and design method of sunroof permanent magnetic direct current motor (PMDCM), this thesis probes into the main parameters and performance of the sunroof motor. In order to improve calculation accuracy, investigation of the effects of calculated finite element model of magnetic circuit design parameters is conducted. Aiming at the sunroof motor and transmission system performance, this study is based on the genetic algorithm and the performance index confirmation which is used to compare with the test data of sample motors.②In order to identify the sunroof motor noise source and the noise level, choosing operation method is used to study the test scheme and the main components of the system noises. According to the requirement that different locations should test signals repeatedly, this thesis studies the noise test method based on ART– 2 and compares and analyzes its noise sources.③Based on the analysis of the cogging torque production mechanism, this thesis studies the influence of the slot-pole match and pole-arc coefficient selection of the sunroof motor of Volvo P1137 on the cogging torque. This study presents pole arc selection method in the case of rotor static eccentric. On the basis of satisfying the motor performance index, this study applies the genetic algorithm to optimize the parameters of motor's structure so as to reduce the cogging torque.The research has obtained certain achievements,especially the acquirement of the method to extract and fuse the noise characteristics frequency of test signals at different positions. The achievements obtained in this research provide some guidelines for the optimal design and noise source identification of the sunroof motor of Volvo P1137. Its characteristic frequency extraction and fusion method can be used in other motor noise source analysis for reference.