Reduction of axial piston pump pressure ripple

2000 ◽  
Vol 214 (1) ◽  
pp. 53-64 ◽  
Author(s):  
K A Harrison ◽  
K A Edge
Keyword(s):  
Piston Pump ◽  
Hydraulic Systems ◽  
Axial Piston Pump ◽  
Flow Ripple ◽  
Speed Flow ◽  
Wide Range ◽  
Pump Delivery ◽  
Pressure Ripple ◽  
Pump Pressure ◽  
Axial Piston

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.

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.

Cavitation in a high-speed aviation axial piston pump over a wide range of fluid temperatures

2021 ◽  
pp. 095765092110469
Author(s):  
Qun Chao ◽  
Zi Xu ◽  
Jianfeng Tao ◽  
Chengliang Liu ◽  
Jiang Zhai
Keyword(s):  
Temperature Effects ◽  
Pressure Pulsation ◽  
Piston Pump ◽  
Limiting Factors ◽  
Fluid Temperature ◽  
Cfd Model ◽  
Axial Piston Pump ◽  
Wide Range ◽  
Fluid Properties ◽  
Axial Piston

The axial piston pump in aerospace applications needs to operate over a wide range of fluid temperatures from −54°C to 135 °C. The fluid properties at such extreme temperatures will significantly affect the cavitation that is one of the major limiting factors for the efficiency and reliability of aviation axial piston pumps. However, it appears that very little of the existing literature studies the effects of extreme fluid temperatures on the pump cavitation. This paper aims to examine the temperature effects on the cavitation in an aviation axial piston pump. First, we develop a three-dimensional (3D) transient computational fluid dynamics (CFD) model to investigate the pump cavitation and validate it experimentally. Second, we use the validated CFD model to investigate the temperature effects on the pump cavitation by changing the fluid properties including viscosity, density, and bulk modulus. The numerical results show that low fluid temperature makes the aviation axial piston pump suffer serious cavitation due to high viscosity, leading to delivery flow breakdown, unacceptable pressure pulsation, and delayed pressure built up. In contrast, high fluid temperatures have minor effects on the cavitation although they increase the pressure pulsation and built-up time slightly.

Novel Piston Pressure Carryover for Dynamic Analysis and Designs of the Axial Piston Pump

2012 ◽  
Vol 135 (2) ◽  
Author(s):  
Shu Wang
Keyword(s):  
Piston Pump ◽  
Axial Piston Pump ◽  
Pump Performance ◽  
Axial Piston Pumps ◽  
Bottom Dead Center ◽  
Pump Pressure ◽  
Definition Of ◽  
And Control ◽  
Axial Piston ◽  
The Relationship

The timing definition of valve plates is one of the most complex topics in the piston pump designs because it affects many pump characteristics (such as efficiency, swashplate stroking, stabilities, noise, etc.). In the study, the pressure carryover is introduced and defined as the average angular positions to locate piston pressure transitions from the top dead center (TDC) or bottom dead center (BDC) in the piston pump. Pressure carryover presents the overall outcome of the pressure transitions within piston bores. The new pressure carryover definition is derived by the timing angles and other geometrics of valve plates that is an approximation of the practical pressure transitions. The pressure carryover also determines the containment forces and moments on the swashplate produced by the pumping pistons. The relationship between the pressure carryover angle and the containment moment has been developed and analyzed in the study. The amplitudes and frequencies of the forces and moments can be changed by varying the pressure carryover angle that produce different tonalities and control efforts for the swashplate type axial-piston pumps. Therefore, the pressure carryover is the most important and straightforward connection between pump dynamics and valve plate designs. In order to optimize the pump performance, the piston pressure carryover might be investigated thoroughly for the pump and its controller designs.

Theoretical and Simulation Investigations on Flow Ripple Reduction of Axial Piston Pumps Using Nonuniform Distribution of Pistons

2020 ◽  
Vol 143 (4) ◽  
Author(s):  
Fei Lyu ◽  
Shaogan Ye ◽  
Junhui Zhang ◽  
Bing Xu ◽  
Weidi Huang ◽  
...  
Keyword(s):  
Flow Rate ◽  
Optimization Design ◽  
Nonuniform Distribution ◽  
Piston Pump ◽  
Axial Piston Pump ◽  
Flow Ripple ◽  
Distribution Rule ◽  
Dynamic Simulation Model ◽  
Ripple Reduction ◽  
Axial Piston

Abstract The output flow ripple of the axial piston pump is one of the excitation sources for the hydraulic system vibration. The amplitudes of its specific harmonics must be reduced to avoid the resonance with the hydraulic pipeline. In this paper, a method on the nonuniform distribution of the pistons is put forward to adjust the flow ripple. The deflection angles of the pistons are used to describe the distribution rule. The distribution rule is imported to the Fourier expansion of the flow rate of each single-piston chamber, and then every single flow rate is superposed to obtain the Fourier coefficient of total flow rate that becomes the function of deflection angles. After this, objective optimization design is carried out to reduce the amplitudes of specific harmonics. Finally, the dynamic simulation model of the nonuniformly distributed axial piston pump is established to verify the effects of objective optimization. The results show that the amplitude of the ninth harmonic of the flow ripple can be reduced by about 40%, and the reductions are about 99% for the 18th and 27th harmonic.

scholarly journals Flow Ripple Reduction of Axial-Piston Pump by Structure Optimizing of Outlet Triangular Damping Groove

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1664
Author(s):  
Haocen Hong ◽  
Chunxiao Zhao ◽  
Bin Zhang ◽  
Dapeng Bai ◽  
Huayong Yang
Keyword(s):  
Numerical Models ◽  
Structural Parameters ◽  
Piston Pump ◽  
Axial Piston Pump ◽  
Discharge Flow ◽  
Flow Ripple ◽  
Ripple Reduction ◽  
Simulation Results ◽  
The Time Domain ◽  
Axial Piston

The triangular damping groove on the valve plate can effectively reduce the discharge flow ripple of an axial piston pump, which structural parameters will directly affect the pump’s dynamic characteristics. Herein, a multi-parameter data-based structure optimizing method of the triangular damping groove is investigated using numerical models and simulation results. The mathematical models of a nine-piston pump are proposed and developed by MATLAB/Simulink, and the simulation results are verified by experimental results. Then, the effects of width angle and depth angle on discharge flow are analyzed. Based on the analysis of groove parameters, an optimizing index, which considering the time domain characteristics of discharge flow, is proposed. As results show, comparing with the initial specific groove structure, the amplitude of flow ripple is reduced from 14.6% to 9.8% with the optimized structure. The results demonstrate that the outlet flow ripple can be significantly reduced by the optimized structure, and the proposed multi-parameter optimizing method can play a guiding significance in the design of low-ripple axial piston pumps.

scholarly journals Research on Control Methods for the Pressure Continuous Regulation Electrohydraulic Proportional Axial Piston Pump of an Aircraft Hydraulic System

2019 ◽  
Vol 9 (7) ◽  
pp. 1376
Author(s):  
Peng Zhang ◽  
Yunhua Li
Keyword(s):  
Feedback Linearization ◽  
Control Method ◽  
Linear Quadratic Regulator ◽  
Piston Pump ◽  
Control Methods ◽  
Hydraulic Systems ◽  
Axial Piston Pump ◽  
Linear Quadratic ◽  
Delivery Pressure ◽  
Axial Piston

The objective of this paper is to design a pump that can match its delivery pressure to the aircraft load. Axial piston pumps used in airborne hydraulic systems are required to work in a constant pressure mode setting based on the highest pressure required by the aircraft load. However, the time using the highest pressure working mode is very short, which leads to a lot of overflow lose. This study is motivated by this fact. Pressure continuous regulation electrohydraulic proportional axial piston pump is realized by combining a dual-pressure piston pump with electro-hydraulic proportional technology, realizing the match between the delivery pressure of the pump and the aircraft load. The mathematical model is established and its dynamic characteristics are analyzed. The control methods such as a proportional integral derivative (PID) control method, linear quadratic regulator (LQR) based on a feedback linearization method and a backstepping sliding control method are designed for this nonlinear system. It can be seen from the result of simulation experiments that the requirements of pressure control with a pump are reached and the capacity of resisting disturbance of the system is strong.

Discharge Flow Ripple of Axial Piston Pump with Conical Cylinder Block

2010 ◽  
Vol 34-35 ◽  
pp. 440-445
Author(s):  
Lei Li ◽  
Jian Ke ◽  
Jia Xu ◽  
Wang Yong
Keyword(s):  
Block Design ◽  
Cone Angle ◽  
Point Of View ◽  
Piston Pump ◽  
Cylinder Block ◽  
Axial Piston Pump ◽  
Discharge Flow ◽  
Flow Ripple ◽  
Displacement Pump ◽  
Axial Piston

The discharge flow ripple is a crucial criterion for evaluating the piston pump. This research examines the discharge flow ripple of axial piston pump with conical cylinder block by developing a comprehensive mathematical model based upon the Bernoulli equation and the continuity equation. The novel aspect of this research is that it includes the analysis of cylinder block cone angle. From the results of this research, it can be concluded that cylinder block cone angle has a significant impact on the discharge flow ripple, and utilizing a conical cylinder block design is more feasible than cylindrical cylinder block from a flow ripple point of view. This conclusion can be used to guide the up-front design for the variable displacement pump.

scholarly journals The Efficiency of Mobile Hydraulic System with Diesel Engine and Axial Piston Pump Analysis

2021 ◽  
Vol 9 ◽  
Author(s):  
Murat Kapsiz ◽  
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Power Unit ◽  
Hydraulic System ◽  
Co2 Emission ◽  
Power Loss ◽  
Piston Pump ◽  
Hydraulic Systems ◽  
Axial Piston Pump ◽  
Axial Piston

Hydraulic systems are used in a wide variety of applications, stationary as well as mobile. Hydraulic pumps und motors are in many cases used for both propulsion and various work functions and is thus often a significant user of energy. Efficiency performance of a mobile hydraulic systems over a wide range of pressure and speed conditions is crucially important for power unit to save energy. In this study, efficiency of a mobile hydraulic system are studied. Mobile hydraulic system is equipped with diesel engine as power unit and axial piston pumps used for hydraulic power. The relationships between the efficiency of the axial piston pump and the power loss, the efficiency of diesel engine and the output power were explained by graphics. The average power loss of axial piston pump have changed from 0.1 kW to 2.5 kW. Losses of an axial piston pump have been determined thus fuel consumption and CO2 emission caused by these losses were shown by graph. The CO2 emission affected by the increase in pressure and speed, it reached from 5.231 kg/h to 5.61 kg/h. The research focused on analysis for axial piston pump in mobile applications, with emphasis on pump losses, fuel consumption and CO2 emission.

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