双离合变速器预选档策略下齿轮敲击动力学分析

双离合自动变速器（Dual clutch transmission，DCT）在预选档状态下具有换档无动力中断和换档平顺等优点，然而在预选档策略下双离合自动变速器的齿轮敲击问题更加突出。以某型湿式双离合变速器为研究对象，分别建立变速器1档无预选以及预选2档下的齿轮敲击动力学模型。模型中各空套齿轮拖曳力矩包括齿轮搅油阻力矩、轴承阻力矩以及同步器阻力矩，此外，模型还考虑了变速器非功率流中未结合状态下离合器所产生的拖曳力矩。齿轮接触模型在考虑齿面弹性接触的基础上，计入了由润滑效应引起的齿隙间非线性油膜力。运用龙格库塔算法对模型求解，获得各齿轮副的动态响应。通过变速器敲击台架试验验证了动力学模型的可行性，计算结果与试验结果具有较好的一致性。对变速器齿轮动力学响应的研究结果表明：在一定角加速度激励下，变速器中空套齿轮存在明显的双面敲击现象；预选档位并不会对无预选状态下已发生敲击的齿轮副产生影响，但是预选档后，变速器非功率流分支发生改变，变速器内空套齿轮数量增多，整体上使变速器敲击问题更加突出。

Dynamic Analysis of Gear Rattle under Pre-selection Strategy of Dual Clutch Transmission

Dual clutch transmission(DCT) has the characteristics of no power interruption and smooth shifting. However, the gear rattle phenomenon of DCT is more obvious after pre-selection. Taking a wet dual clutch transmission as the research object, without considering the shifting process of the transmission, the dynamic models of gear rattle in the 1st gear without pre-selection and preselect the 2nd gear are established respectively. In the model, the drag torque of each loose gear includes the drag torque of oil churning, bearing and synchronizer. In addition, the drag torque generated by the clutch in the non-power flow of the transmission is also considered. Based on considering the elastic contact of tooth surface, the gear contact model takes into account the nonlinear oil film force caused by lubrication effect. Runge-Kutta algorithm is used to solve the model, and the dynamic response of each gear pair is obtained. The feasibility of the dynamic model is verified by bench test, and the calculated results are in good agreement with the experimental results. The dynamic response of transmission gear is studied. The results show that the loose gear of transmission has obvious double-sided rattle phenomenon under certain angular acceleration excitation; pre-selection will not affect the gear pair that has been rattled without preselected gear, but after preselected gear, the non-power flow branches of the transmission will change, and the number of loose gears in the transmission will increase, which makes the rattle phenomenon of the transmission more obvious.