Energy efficency improvement of timing chain drives

内燃机的正时组件更多地被设计成链传动。与齿带传动相比，正时链传动具有占用空间小、维护和购置成本低等优点。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，以确保运行安全。张紧力的传递是通过液压张紧系统完成的，液压张紧系统通过链条上的滑动接触传递力。能效较低的原因是链条接触。在第一阶段(DFG SA 898/10-1)，研究了降低正时链条传动功率损失的方法。研究了基于需要调整各作业点的链条张紧力、优化润滑油供应和优化钢轨表面的方法。在这样做的过程中，找到了一些积极的方法。这些测试是在试验台上的稳态操作点进行的，包括气门机构的振荡。在下一步中，将考虑曲轴和活塞的振动，以及气体力引起的旋转不平顺。此外，还考虑了暂态运行条件。此外，还将进一步发展定向润滑的积极方法，并将对织构链板进行研究。

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.