Flow Field Simulation And Optimization Design Of Internal Engagement Cycloidal Pump

Internal-Meshing Cycloid rotary has the advantages of compact structure, small pulse rate and high volume efficiency and it is widely used in various types of vehicles and engineering equipment, but because of the difficulties of its design, manufacturing technology, there is little mature products in home at present. Based on the problems of local wear and low volumetric efficiency in the engineering practice of the Internal-Meshing Cycloid rotary, this paper studies the implementation scheme and Structure optimization of variable displacement of the Internal-Meshing Cycloid rotary, combined with the development trend of high pressure and variable displacement, which provides reference for the research and development of new products of high performance. Besides, it has certain practical significance to improve the comprehensive performance and market competitiveness of the domestic pump products.In this paper, the variable displacement pump is the research object and the following points have been studied:(1) In this paper, the key structural parameters of the pump and the constraint relations between them are studied and the profile curve equation of conjugate tooth for the inner and outer rotor of variable displacement pump is derived based on the structure parameters and the meshing transmission conditions of Inner and outer rotor, which provides full preparation for further mathematical modeling and numerical simulation; this paper also puts forward a scheme of variable displacement of the rotor pump and finishes related structure improvement and design calculation, particularly, finishes the design calculation of theoretical verification and variable mechanism of variable displacement scheme.(2) Based on the theoretical analysis of variable displacement pump, the paper studies the meshing characteristics of inner and outer rotor profile theoretically, determines high wear area of tooth profile, puts forward the improvement scheme of the local shift distance repair for inner and outer rotor profile curve, finishes the durability test of the inner and outer rotor of variable displacement pump, and proves the feasibility of the improved scheme. And according to the design calculation parameters, the paper finishes the digital prototype and three dimensional model of internal fluid field of the variable displacement pump using the software of Pro-e.(3) Based on the fluid model and the computational fluid dynamics(CFD) method, the numerical simulation of variable displacement pump in different working conditions was completed by using the professional simulation software of pump. In addition, through the comparative analysis of the flow field characteristics, the feasibility of variable displacement scheme is verified.(4) According to the experimental standard of hydraulic gear pump, the performance test of variable displacement pump is designed and completed. In this paper, the variation law of volumetric efficiency with the displacement, the outlet pressure, the rotational speed and the main influence factors are obtained, and the rationality of the simulation results and the feasibility of the variable displacement scheme are verified by the comparison.