Energy efficency improvement of timing chain drives

内燃机的正时组件通常设计为链传动。与齿带传动相比，正时链传动具有许多优点，例如对空间的需求更低，维护和购置成本更低。正时链传动的唯一缺点是能源效率较低。正时链传动的链条必须几乎完全导向和张紧，以确保操作安全。张紧力的传递是通过液压张紧系统完成的，该系统通过链条上的滑动触点传递力。较低的能源效率是由于链轨接触。在第一个阶段（DFG SA 898/10-1）的方法进行了研究，其中正时链驱动的功率损耗降低是可能的。研究了各工作点链条张紧力的需求调整、润滑油供给的优化和钢轨表面的优化等方法。在这样做时，发现了一些积极的办法。测试是在试验台的稳态工作点上进行的，包括气门机构的振荡。在下一步中，将考虑曲轴和活塞的振荡以及由气体力引起的旋转不规则性。此外，还考虑了暂态工况。进一步发展定向润滑的积极途径，对织构连杆板进行研究。

Timing assemblies of internal combustion engines are more often designed as chain drive. Compared to tooth belt drives, timing chain drives have many advantages, such as the lower need of space and lower costs for maintenance and acquisition. The only disadvantage of timing chain drives is the lower energy efficiency. The chain of a timing chain drive hast to be almost completely guided and tensioned to ensure operational safety. The transfer of tensioning force is accomplished via a hydraulic tensioning system, which transmits the force via sliding contacts on the chain. The lower energy efficiency is due to the chain-rail contacts. In the first period (DFG SA 898/10-1) approaches were investigated, with which a power loss reduction of timing chain drives is possible. Approaches as the need-based adjustment of chain tensioning force at each operating point, the optimization of the lubricant supply and the optimization of the rail surface were investigated. In doing so, some positive approaches were found. The tests were conducted at steady-state operating points on a test stand, including the oscillations of the valve train. In the next step, the oscillations of the crankshaft and pistons, and the rotation irregularities caused by the gas forces will be taken into account. In addition, transient operating conditions are considered. Furthermore, the positive approaches of targeted lubrication will be further developed and investigations on textured link plates will be conducted.