Design And Research On Super-Long Large Scale Hydraulic Cylinder

The super-long large scale hydraulic cylinder has been widely used in large mechanical engineering field, large equipment manufacturing and ship industry. It plays an important role in national economy development. However, analyses and design of the super-long large scale hydraulic cylinders are all specific and focus on relevant cases. The design standard and procedure are imperfect. This thesis made design&check methods and processes of the super-long large scale hydraulic cylinder according to dynamic and static performances shown during work process. Then took hydraulic hoist cylinder as an example and designed and optimized the specific procedure. Finally, the ANS YS analysis and load test are conducted to verify.The thesis analysis viscosity and compressibility of hydraulic oil and effect of the hydraulic spring, based on which the thesis analyzed dynamic and static performances of the super-long large scale hydraulic cylinder. The thesis mainly analyzed creeping due to inertia of the cylinder and compressibility of oil during instantaneous change; creeping suffered influence of nonlinear friction and nonlinear spring force during low velocity movement; the dynamic characteristic restriction or elimination measures.According to the dynamic and static performances, the working environment and basic performance parameters, this thesis determine the general structural pattern of the super-long large scale hydraulic cylinder and connection types between components, and then worked out materials, technical requirements and main parameters of cylinder barrel components, piston rod components, sealing unit, guiding unit, buffering unit and other parts. Finally, the thesis verified all components and the entire device. Furthermore, the thesis studied the super-long large scale hydraulic cylinder with installing angle.Taking the horizontal hydraulic hoist cylinder of hydraulic engineering as an example, the specific design calculation of the super-long large scale hydraulic cylinder is made. The structural pattern and connection type of components is determined. Structure and dimensions sketches of all the parts are drawed, and checking is carried out. Finally, the thesis launched optimal design combined the GA and the complex method. The effects of the cooperated clearance between the cylinder rod, and the friction coefficient between the earrings and the bearing shaft pin, and installing angle on the axial bearing capacity are investigated.ANSYS analysis and experimental verification of the super-long large scale hydraulic cylinder is performed. The ANSYS eigenvalue buckling analysis is carried out to the stability checking. And the ANSYS nonlinear buckling analysis to the stiffness checking is carried out. By changing the fit clearance between the cylinder and the piston rod, and changing the friction coefficient between the earrings and the bearing shaft pin on the axial bearing capacity, the corresponding maximum axial loads are obtained. Modality analysis is done on hydraulic hoist cylinder. The FEA results are compared with the theoretical model, in order to verify the correctness of the theoretical model calculation and analysis. Finally, load test for the axial bearing capacity of hydraulic cylinder modality analysis is conducted, to verify the rationality of the theoretical analysis.This thesis made theoretical design and study on the super-long large scale hydraulic cylinder, not only make it meet all requirements of the working environment technically but also optimize it economic performance. The study provides certain theoretical reference for manufacturing and industrialization of the super-long large scale hydraulic cylinder.