Contrastive Study on the Guide Curves of the Multipleaction Constant Axial Piston Pump 

Author  ChenXiaoPing 
Tutor  PengYouDuo；LuoJianRong 
School  Hunan University of Science and Technology 
Course  Mechanical Design and Theory 
Keywords  Multipleaction constant axial piston pump Guide curve Flow pulse characteristic Contrastive study Simulation Hydrostatic bearing 
CLC  TH322 
Type  Master's thesis 
Year  2010 
Downloads  82 
Quotes  1 
The flow pulse is not only the root of the hydraulic system, which causes the pressure shock, vibration, noise, system false action, even the whole hydraulic system damage, but also is the main factor of limiting the improvement of the performance of high response Electrohydraulic system. It is an important research subject in developing and designing hydraulic pump that how to reduce the flow pulse of the hydraulic pump and without making the structure of the hydraulic pump too complicated. The Multipleaction constant axial piston pump is a new type of hydraulic pump without flow pulse in theory, it adopts the multipleaction curve plate which has been specially designed to realize the same discharge proximately at any moment, that is to say, the constant discharge is realized.The structure and principle of the Multipleaction constant axial piston pump are introduced briefly, in addition, the core structure is explained in the thesis, a contrastive study on the motion property of piston and the flow pulse property of pump of the uniformly accelerating guide, the 8 degree equation guide and the sine acceleration guide is completed. The mathematical models of the axial displacement, speed, acceleration are presented of the uniformly accelerating guide, the 8 degree equation guide and the sine acceleration guide are simulated with MATLAB separately, the simulation graphs of instantaneous velocity of one piston in 2πcycle of guides are got; the mathematical models are presented which are the sum of instantaneous velocity of all pistons in all discharge sections in 2πcycle of the uniformly accelerating guide, the 8 degree equation guide and the sine acceleration guide, and the simulation is programed by using MATLAB, the simulation graphs are got which are the sum of instantaneous velocity of all pistons in all discharge sections in 2πcycle of the corresponding guides, and the values of NonUniform coefficient under different piston number of the Multipleaction constant axial piston pump are got, the results indicate that the value of NonUniform coefficientδQ of the Multipleaction constant axial piston pump is much lower than the normal hydraulic pumps’, which can be reguarded as noflow pulse proximatly; the NonUniform coefficient value of the Multipleaction constant axial piston pump changes in a less size when the piston number is odd number than even number; and the mathematical models and simulation are presented for the supporting forces of guides to the piston and the side slanting forces of cylinder wall to the piston, when the Multipleaction constant axial piston pump adopts the uniformly accelerating guide, the 8 degree equation guide and the sine acceleration guide separately, and a kind of structure of hydrostatic bearing is proposed.In conclusion, the Multipleaction constant axial piston pump gets the optimal synthetical characteristic when it adopts the 8 degree equation guide, through a comprehensive comparison of the motion property of piston, the flow pulse property of pump and the force status of piston.