An approach of localizing the contact zone of the double-envelope hourglass worm gearing has been proposed to reduce the sensitivity to the errors and the load. The influence of the errors on the contact zone is systematically investigated. The contact deformation, the shift of contact zone and load share among the meshing tooth-pairs has been analyzed using 3D contact FEM. After synthetically considering the influence of the errors and the load, the worm surface is modified into the crowning in height direction in comparison with the hob. The results from the loaded contact analysis demonstrate that this modification drive can absorb the influence of the errors and the load on meshing performance

By the bond graph theory, a bond graph analysis model of continuously variable transmission is established. On the basis of improving the ratio change response and reducing the engine torque response lag in normal control, a new synthetic control algorithm is developed. By analyzing the engine driving torque characteristics and the transmission inertia torque while ratio is changed under transient condition, the compensation value for engine driving torque is presented. The simulation result shows that by this compensation control algorithm the engine torque response lag can be reduced and the driving torque response can be improved effectively.

回顾和论述了机械传动科学技术的发展历史和研究进展。认为：机械传动作为机械系统的重要组成部份，其科学技术的发展和机械系统一样，是与人类生产力水平的发展而相伴的。生产力水平的发展对机械系统的性能提出了新的要求，而机械系统的原动机、工作机为满足生产力水平而产生的突破性进展对传动机提出的要求推动了机械传动科学技术的进步。21世纪信息与控制技术、能源与环境保护技术、新材料技术、先进制造技术等成为科学技术发展的重要领域，这些领域的科技进步对机械传动科学技术的发展将产生重要的推动作用。

采用金属带―行星齿轮无限级变速传动系统的并联式混合动力汽车，具有在相同动力性能下所需电动机功率小、燃油消耗少、废气排放低等特点。应用键合图理论，分析了双模态型并联式混合动力汽车的发动机、电动机及离合器等部件的性能参数以及变速器速比在汽车加速行驶过程中的变化规律，从而为进一步开发并联式混合动力汽车提供理论设计依据。

介绍了采用起动机/发电机/电动机一体化技术的ISG（Integrated starter/generator）型混合动力汽车动力传动系统结构及控制策略，建立了装备双模式无级变速传动系统的ISG型混合动力汽车起步加速过程的动力学模型，并进行了计算机仿真。提出了轻度混合动力汽车动力系统的匹配设计方法，分析了电动机峰值功率、启动转矩和发动 机启动转速对整车动力性能和传动系统转矩响应的影响，为轻度混合动力汽车总体设计提供了理论依据。