A Fast and Effective Method for the Optimization of the Valve Plate of Swashplate Axial Piston Pumps

Author(s):  
Gianluca Marinaro ◽  
Emma Frosina ◽  
Kim Stelson ◽  
Adolfo Senatore

Abstract This research presents a lumped parameter numerical model aimed at designing and optimizing an axial piston pump. For the first time, it has been shown that a lumped parameter model can accurately model axial piston pump dynamics based on a comparison with CFD models and experimental results. Since the method is much more efficient than CFD, it can optimize the design. Both steady-state and dynamic behaviors have been analyzed. The model results have been compared with experimental data, showing a good capacity in predicting the pump performance, including pressure ripple. The swashplate dynamics have been investigated experimentally, measuring the dynamic pressure which controls the pump displacement; a comparison with the numerical model results confirmed the high accuracy. An optimization process has been conducted on the valve plate geometry to control fluid-born noise by flow ripple reduction. The NLPQL algorithm is used since it is suitable for this study. The objective function to minimize is the well-known function, the Non-Uniformity Grade, a parameter directly correlated with flow ripple. A prototype of the best design has been realized and tested, confirming a reduction in the pressure ripple. An endurance test was also conducted. As predicted from the numerical model, a significant reduction of cavitation erosion was observed.

Author(s):  
Emma Frosina ◽  
Gianluca Marinaro ◽  
Adolfo Senatore

Abstract In this paper an axial piston pump is studied using numerical and experimental approaches. The pump, manufactured by the company Continental Hydraulic Inc., has a maximum operating pressure limit of 280 bar and a displacement of 65.9 cm3/rev; it is a variable swashplate design with nine-piston, suitable for open circuit application, medium to high pressure. Two numerical approaches have been compared to simulate the pump units. First of all, an accurate 3D -CFD model has been built up putting emphasis on the description of the detailed features of the flow through the unit. Specific attention has been reserved to the flow losses due to cavitation. Then a fast-lumped parameter approach has been built up focusing the attention on the valve plate geometry. Using the proposed numerical approaches, it is possible to fully understand the unit operation with, obviously, different assumptions and level of result details. Numerical models have been validated with an experimental data performed by the pump manufactured on their test ring with high agreement. As results, the proposed analysis permit to gain a high level of understanding of the operation of the unit finding the critical aspects and giving important information to the designer in order to improve the pump performance. By the end a new valve plate has been designed to improve the pump volumetric efficiency and to reduce the flow ripples and the reverse flow.


Author(s):  
Shusen Zhang ◽  
Noah D. Manring ◽  
Viral S. Mehta

In this paper, the theoretical optimal timing of the axial piston pump is first derived to confirm the analysis published by Professor Kevin Edge [1]. It is discovered that the optimal discharge port delay is different from the optimal inlet port delay. The dimensional analysis also shows that higher shaft angular velocity indicates less delay required in both discharge port and inlet port. Numerical studies show that optimal timing can reduce the dynamic pressure ripple greatly, but since it does not affect the kinematic component, it will not eliminate the entire pressure ripple. The optimal timing could also induce an increase in efficiency where the baseline pump design has cross-porting. However, there is certain tradeoff between pressure ripple reduction and efficiency consideration. Actual design consideration to affect independent timing of the portplate is not studied in this work.


2012 ◽  
Vol 157-158 ◽  
pp. 1549-1552
Author(s):  
Jiang Zhai ◽  
Hua Zhou

With cavitation model being considered, a LP (Lumped Parameter) model and a CFD (Computational Fluid Dynamics) model on the flow and pressure characteristics of the axial piston pump for seawater desalination were created. Based on the geometry structure and operating condition of the pump, these two models were numerically calculated and corresponding results were compared and discussed. Both the two models can describe the dynamic flow and pressure characteristics of the pump. The CFD model is accurate and many details such as cavitation position can be predicted. LP model is a simplified model compared with CFD model. Because the damping effect of the inlet of the pump is neglected, this model is only suitable for rough calculation in engineering.


Author(s):  
Ganesh Kumar Seeniraj ◽  
Monika Ivantysynova

In designing an axial piston pump, lot of attention is given to the design of the valve plate. A well designed valve plate can reduce both flow pulsations as well as oscillating forces on the swash plate. In the presented study, a computational tool, CASPAR, has been used for investigating the effect of valve plate design on flow ripple (fluid borne noise), oscillating forces (structure borne noise) and volumetric efficiency. The impact of various valve plate design parameters such as precompression grooves, cross port, indexing and additional precompression volume will be presented using simulation results from CASPAR. The study also details how rate of pressurization and decompression inside the displacement chamber directly relate to the flow ripple, forces applied on swash plate and the control effort needed to stroke the swash plate. The effect of noise reduction techniques on volumetric efficiency will also be presented with simulated results.


Author(s):  
K A Harrison ◽  
K A Edge

The reduction in source flow ripple in hydraulic systems is the most effective method of reducing pump-generated pressure ripple and system noise. This paper describes reductions in axial-piston pump delivery flow ripple achieved using a novel timing mechanism which is inherently speed, flow and pressure sensing. Fixed-speed tests have shown that the mechanism can significantly reduce axial-piston pump delivery flow ripple over a wide range of delivery pressures and pump displacements. Furthermore, the reduction in pressure ripple achieved with the mechanism has been shown to contribute towards reductions in overall air-borne noise levels of up to 6 dB in a simple system. A simulation model has been produced to predict the behaviour of the prototype mechanism. The model has been compared with the measured delivery flow ripple and achieves good agreement.


AIP Advances ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 115221
Author(s):  
Jihai Jiang ◽  
Boran Du ◽  
Jian Zhang ◽  
Geqiang Li

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