Design Of Piston Connecting Rod Group Of Dual Power Engine

Dual power output engine can simultaneously export two kinds of power, mechanical and hydraulic power. It has broad prospects in the field of engineering mechanic. As the main parts of dual power output engine, it is critical to make a right design and optimization on the structure of piston and connecting rod assembly.In this paper, the operating principle of the engine-pump system is disserted. This paper also discourses the classification, operating principle and research status at home and aboard of the hydraulic free piston engine(HFPE). The research status of crankshaft and connecting rod system is expounded in this paper. The whole scheme of dual power output engine is disserted. The structural composition and the operating principle of dual power engine are described in this paper.Calculation and design are done on the piston and connecting rod assembly of dual power engine in this paper, and the assemblies are established by Solid Works software. The motion interference is checked. In maximum compression condition and in maximum stretch condition, the FEM strength analysis is done on the connecting rod of dual power output engine by ANSYS Workbench, and the equivalent stress cloud and deformation cloud are achieved respectively. The safety factor of connecting rod’s fatigue is also calculated.By analyzing the results of FEM strength analysis, we conclude that the strength coefficient of the connecting rod is sufficient and enough, and the structure can be further optimized in order to reduce the weight, save materials and lower inertial force. The structural optimization is done by Design Explorer of ANSYS Workbench in this research. The outside diameter of the small end of connecting rod and the half thickness of connecting rod body are selected as input parameters, and the connecting body’s mass, the maximum deformation of connecting rod and the maximum stress are selected as output parameters to optimize the connecting rod’s structure. The main goal of the optimization is reducing the mass of connecting rod body possibly under the constraint condition that the strength and stiffness are sufficient and enough. By comparing the maximum stress, maximum strain and fatigue safety factor before and after optimization, we know that the optimized connecting rod meets the design requirements, and the mass of the connecting rod body is reduced by 4.5%,therefore, the goal is achieved.