Analyses Of Front Engine Accessory Drive System Tensioner

Currently， in the modern automobile engines， extensive use of belt-drivengenerators，air compressors，fans and other engine accessories．Belt drive is a commonform of transmission，it has a simple structure，stable transmission，low cost andvibration absorption characteristics of the buffer，so widely used．However，in tensionwith the size of the zone can directly affect the size and the power transmission belt oflife. The front engine accessory drive system in tension during operation unstable，vibration and noise characteristics，development of the front engine accessory drivesystem with auto-tensioner，it is very important for belt-driven system．Based on this，design an appropriate damping to suppress the belt vibration noise is very difficult.Because of this difficult, there is a great problem in inhibition precisely belt noise andvibration. This article is mainly on the research of imported auto tension belt pulley forthe engine of certain car theoretically and practically, using the theoretical analysis andfinite element method to study the structural design for front engine accessory drivetension system．Design theory and technological guidance are investigated for thepurpose of local manufacturing of the auto tension belt pulley．The main works of thisproject have been done are introduced in this thesis．1). Force analysis of the tensioner. Force analysis of the tensioner belt pulley isdone．The working mechanism of the tensioner is studied. Then analyzed the structuredamping mechanism, and its generation mechanism.2).Rotation rigidity calculate of the spring in tensioner. Established a mathematicalmodel precisely the spring. It’s very different with finite element result, then analysisthe different. Comparing with finite element result, revise the mathematical model.Calculate the relationship between torque and spring rotate angle and validated usingfinite element result.3).Theoretical calculation of the tensioner. The working mechanism of the dampingparts is studied, then established a mathematical model of damping device. Calculatethe relationship between torque and tensioner rotate angle and validated usingexperiment data, and analysis the influence factors on the torque damping of thetensioner．4).Finite element method to calculate the tensioner. In order to gasp the relationshipbetween torque and tension angle accurately, established the finite element model the tensioner，according to the boundary condition and constraints，analysis the finiteelement model of the tensioner，simulation exercise on the tensioner，and then the worktorque and damping are received．5).Tensioner optimize design and verification. According to the spring stiffness,torque and damping value of target from the optimization and design of front engineaccessory drive system，makes the optimization design of tension device above theanalysis. Established the finite element model the new tensioner, to verify the optimizedtensioner meets the overall design requirements.This article studied the working mechanism of the tensioner, analyzed the structuredamping mechanism. Then according to the optimization and design of front engineaccessory drive system, makes the optimization design of tension.