Study on automatic compensation variable clearance sealing hydraulic cylinder

As an important component of hydraulic system, hydraulic cylinder is a kind of energy conversion element that converts pressure energy into mechanical energy, and its performance directly affects the performance of the hydraulic system. Because the first generation of hydraulic cylinder with sealing parts has great friction resistance, the development of hydraulic cylinder towards high speed and high frequency is restricted. The second generation of hydraulic cylinder with constant clearance non-sealing parts has low friction resistance and improves dynamic response, however, the capacity efficiency is reduced and the requirement of machining precision is high. On the basis of the second generation of hydraulic cylinder, the third generation of hydraulic cylinder with pressure automatic compensation variable clearance sealing is developed by applying the elastic-plastic theory and the gap flow theory of fluid mechanics. Through analysis, modeling, simulation and experiments, it is proved that the third generation of hydraulic cylinder has characteristics of good static and dynamic performance, high volumetric efficiency and long working life, and is suitable for hydraulic system with high frequency and high speed. The pressure automatic compensation variable clearance sealing technology can also be applied to other hydraulic components and related fields.