Design And Wear Test Analysis Of Engine Timing Chain System

Automotive engine timing chain drive chain as an important model of chaindrive with many advantages has been widely used. The automotive timing chain isworking on high-speed, multicycle impact, as well as alternating speed and load,meanwhile, its transmission power and speed is far beyond the Rated Power Curves ofthe same model common roller chain. Therefore, the design method and failure modeof timing chain system is different from the normal chain drive system. Consequently,it is of great significance to take research on the failure analysis of timing chain anddesign method of timing chain system for improving the overall design level of enginetiming chain system.Firstly,the angular velocity fluctuations of driven sprocket in a variety of possiblewere analyzed in the case of driving sprocket with constant angular velocity andconsidering the angle between centre line of chain and the horizontal,also pointed outthat in some cases, driven sprocket angular velocity is approximately piecewise linearcurve, rather than the sine or cosine curve in the traditional analysis.Based on the traditional analytical method, completed the timing chain systemdesign by using the computer aided design, and provided the calculation method ofchain length and design method of tensioner and damper guide plate, meanwhile, athree-shafts timing chain system was designed step by step.In AVL-TYCON software,a three-shafts timing chain system was built to dynamic simulation analysis, tensionof chain link, chain transverse vibration, angular velocity fluctuations of camshaftsprocket and tensioner guide plate as well as tensioner force were analyzed.Finally, the failure modes of timing chain were studied, fatigue life of inner andouter chain plates were computed with multiple load cases in a variety of chainelongation.Simultaneously, contact stress curves on the line that micro-crack prefersto occur were drawn and the initiation location of micro-cracks on the contact surfacewas analyzed. Chain durability test with close power flow was developed, wearcharacteristics of timing chain and surface characteristics of pin, sleeve and rollerwere analyzed.