Optimal Calculation And Noise Analysis Of Pulley Alignment Of Engine Front End Accessory Drive System

Engine Front End Accessory Drive system(EFEAD system) is a very important power subsystem of a car engine. Currently, the V-ribbed belt is widely used in the EFEAD system to drive all the accessories due to its superior performance. However, in the transmission process, the abnormal wear and offset problems of the V-ribbed belt will adversely affect the car engine, producing unwanted vibration and noise. Therefore, concerning the noise and vibration problems of the EFEAD system, the major research work of this paper can be summarized as the follows:1. The pulley alignment of the EFEAD system is defined. And it also describes the hazards of the pulley misalignment error, the manifestation of the pulley misalignment error and the effects of the pulley misalignment error on the V-ribbed belt service life.2. Provide the calculation methods of V-ribbed belt’s effective length and different types of pulley diameters. Give the spatial geometry model and the linear optimization mathematical model for two main kinds of EFEAD systems to calculate the pulley misalignment errors(including the parallel and angular misalignment errors). Finally, use the Matlab software to calculate the coordinate range of z-axis direction of each grooved pulley in the reference plane.3. Study the effective methods to decrease the wear of the V-ribbed belt and the noise of the EFEAD system, due to the pulley misalignment error, from three aspects: the layout of the EFEAD system, the winding direction of the V-ribbed belt and the tension fluctuation range of the two adjacent belt spans around the automatic tensioner. In addition, the measuring equipment, process and method of the pulley misalignment error are described in detail.4. Analyze the reasons for the noise of the EFEAD system and introduce the noise test equipment and test machine. Based on the experimental data, the characteristics of different types of the EFEAD system noise(dry slip noise, wet slip noise and misalignment noise) are summarized. Finally, provide a systematical testing process and method which is suitable for engineering application to measure the EFEAD system noise.