The Improved Volumetric-Efficiency of an Axial-Piston Pump Utilizing a Trapped-Volume Design

2000 ◽  
Author(s):  
N. D. Manring ◽  
Y. Zhang
Keyword(s):  
Volumetric Efficiency ◽  
Valve Plate ◽  
Piston Pump ◽  
Operating Efficiency ◽  
Axial Piston Pump ◽  
Plate Design ◽  
Design For All ◽  
Analytical Result ◽  
Axial Piston ◽  
Insight Into

Abstract In this research, the volumetric efficiency of the axial-piston pump is examined as it relates to the compressibility losses of the fluid. In particular, two valve-plate geometries are compared to show that alterations in the valve-plate design can cause differences in the operating efficiency of the pump. In this paper, a standard valve-plate design which utilizes slots is compared to a trapped-volume design which eliminates the slots altogether. In the analytical result of this paper, it maybe shown that the standard valve-plate design introduces a volumetric loss which may be accounted for by the uncontrolled expansion and compression of the fluid that occurs through the slots themselves. By eliminating these slots, and utilizing a trapped volume design, it may be shown that improvements in the operating efficiency can be achieved. Though this paper does not claim to provide the ideal valve-plate design for all pump applications, it does provide the theoretical reason for utilizing trapped volumes and lends general insight into the overall problem of valve-plate design.

The Improved Volumetric-Efficiency of an Axial-Piston Pump Utilizing a Trapped-Volume Design

2000 ◽  
Vol 123 (3) ◽  
pp. 479-487 ◽  
Author(s):  
Noah D. Manring ◽  
Yihong Zhang
Keyword(s):  
Volumetric Efficiency ◽  
Valve Plate ◽  
Piston Pump ◽  
Operating Efficiency ◽  
Axial Piston Pump ◽  
Plate Design ◽  
Design For All ◽  
Analytical Result ◽  
Axial Piston ◽  
Insight Into

In this research, the volumetric efficiency of the axial-piston pump is examined as it relates to the compressibility losses of the fluid. In particular, two valve-plate geometries are compared to show that alterations in the valve-plate design can cause differences in the operating efficiency of the pump. In this paper, a standard valve-plate design which utilizes slots is compared to a trapped-volume design which eliminates the slots altogether. In the analytical result of this paper, it may be shown that the standard valve-plate design introduces a volumetric loss which may be accounted for by the uncontrolled expansion and compression of the fluid that occurs through the slots themselves. By eliminating these slots, and utilizing a trapped volume design, it may be shown that improvements in the operating efficiency can be achieved. Though this paper does not claim to provide the ideal valve-plate design for all pump applications, it does provide the theoretical reason for utilizing trapped volumes and lends general insight into the overall problem of valve-plate design.

Impact of Valve Plate Design on Noise, Volumetric Efficiency and Control Effort in an Axial Piston Pump

2006 ◽  
Author(s):  
Ganesh Kumar Seeniraj ◽  
Monika Ivantysynova
Keyword(s):  
Volumetric Efficiency ◽  
Valve Plate ◽  
Piston Pump ◽  
Design Parameters ◽  
Axial Piston Pump ◽  
Control Effort ◽  
Flow Ripple ◽  
Swash Plate ◽  
Plate Design ◽  
Axial Piston

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.

Valve-Plate Design for an Axial Piston Pump Operating at Low Displacements

2003 ◽  
Vol 125 (1) ◽  
pp. 200-205 ◽  
Author(s):  
Noah D. Manring
Keyword(s):  
Rate Of Change ◽  
Valve Plate ◽  
Piston Pump ◽  
Maximum Pressure ◽  
Axial Piston Pump ◽  
Plate Design ◽  
Pressure Time ◽  
Constant Area ◽  
Axial Piston ◽  
Principal Advantage

The objectives of this research are to investigate the principal advantages of using various valve-plate slot geometries within an axial piston pump. In particular, three types of geometries are considered: a constant area slot geometry, a linearly varying slot geometry, and a quadratically varying slot geometry. By analyzing the pressure transients that are associated with each design at low pump displacements, it is shown that the magnitude of the pressure transition itself and the maximum pressure time rate-of-change may be specified for each design. In conclusion, it is shown that the constant area slot design exhibits the principal advantage of minimizing the required discharge area of the slot, the linearly varying slot design exhibits the principal advantage of utilizing the shortest slot length, while the quadratically varying slot design exhibits no principal advantage over either of the other two designs. The results of this research suggest that the use of quadratically varying slot geometry is not justified since it offers no obvious performance improvement.

Lubrication and Dynamic Characteristics of a Cylinder Block in an Axial Piston Pump

2005 ◽  
Author(s):  
S. Y. Ahn ◽  
Y. C. Rhim ◽  
Y. S. Hong
Keyword(s):  
Numerical Simulation ◽  
Degrees Of Freedom ◽  
Volumetric Efficiency ◽  
Valve Plate ◽  
Piston Pump ◽  
Cylinder Block ◽  
Axial Piston Pump ◽  
Hydraulic Unit ◽  
Lubrication Characteristics ◽  
Axial Piston

Lubrication characteristics between a cylinder block and a valve plate in axial piston pumps play an important role in volumetric efficiency and durability of a hydraulic unit. In this paper, the finite element method is used for the computation of the pressure distribution between a cylinder block and a valve plate of the axial piston pump. Also, the Runge-Kutta method is applied to simulate the dynamics of a cylinder block of three-degrees of freedom motion. From the results of computation, two major conclusions are drawn. One is related to the fluid film characteristics between a cylinder block and a valve plate, and the other is related to the average leakage flow rate which is determined by the pressure gradient and the clearance near the discharge port. To confirm results of numerical simulation of cylinder block dynamics, experiment is conducted using three eddy-current type gap sensors, which are imbedded at the pump housing. Finally, a revised shape of a valve plate is proposed which increases the stability of the cylinder block dynamics and the volumetric efficiency of the pump based on numerical simulation.

scholarly journals Novel design of hydrodynamic–magnetic compound support for cylinder block–valve plate in axial piston pump

AIP Advances ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 115221
Author(s):  
Jihai Jiang ◽  
Boran Du ◽  
Jian Zhang ◽  
Geqiang Li
Keyword(s):  
Valve Plate ◽  
Piston Pump ◽  
Cylinder Block ◽  
Axial Piston Pump ◽  
Axial Piston ◽  
Novel Design

Improving the Volumetric Efficiency of the Axial Piston Pump

2012 ◽  
Vol 134 (11) ◽  
Author(s):  
Shu Wang
Keyword(s):  
Operating Conditions ◽  
Volumetric Efficiency ◽  
Valve Plate ◽  
Piston Pump ◽  
Efficient Design ◽  
Axial Piston Pumps ◽  
Definition Of ◽  
Engineering Practices ◽  
First Time ◽  
Axial Piston

The volumetric efficiency is one of the most important aspects of system performance in the design of axial piston pumps. From the standpoint of engineering practices, the geometric complexities of the valve plate (VP) and its multiple interactions with pump dynamics pose difficult obstacles for optimization of the design. This research uses the significant concept of pressure carryover to develop the mathematical relationship between the geometry of the valve plate and the volumetric efficiency of the piston pump. For the first time, the resulting expression presents the theoretical considerations of the fluid operating conditions, the efficiency of axial piston pumps, and the valve plate designs. New terminology, such as discrepancy of pressure carryover (DPC) and carryover cross-porting (CoCp), is introduced to explain the fundamental principles. The important results derived from this study can provide clear recommendations for the definition of the geometries required to achieve an efficient design, especially for the valve plate timings. The theoretical results are validated by simulations and experiments conducted by testing multiple valve plates under various operating conditions.

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

2021 ◽  
Author(s):  
Gianluca Marinaro ◽  
Emma Frosina ◽  
Kim Stelson ◽  
Adolfo Senatore
Keyword(s):  
Numerical Model ◽  
Dynamic Pressure ◽  
Valve Plate ◽  
Lumped Parameter Model ◽  
Piston Pump ◽  
Axial Piston Pump ◽  
Flow Ripple ◽  
Lumped Parameter ◽  
Pressure Ripple ◽  
Axial Piston

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.

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