The Pumping Dynamics of Swash Plate Piston Pumps

1989 ◽  
Vol 111 (2) ◽  
pp. 307-312 ◽  
Author(s):  
K. A. Edge ◽  
J. Darling
Keyword(s):  
Cross Section ◽  
Cylinder Pressure ◽  
Test Results ◽  
Axial Piston Pump ◽  
Flow Ripple ◽  
Swash Plate ◽  
Hydraulic Axial Piston Pump ◽  
Relief Groove ◽  
Improved Model ◽  
Axial Piston

This paper describes a study of the cylinder pressure and flow in an oil hydraulic axial piston pump. A comparison is made between a theoretical model based on the effects of fluid compliance within the cylinder, and an improved model which accounts for the influence of oil momentum in the port plate region. The improved model is validated by comparison with experimental test results and is used to analyze the influence of port plate and relief groove design on cylinder pressure and pump flow ripple. A steeply sloping triangular cross-section groove was found to be the most satisfactory design.

Study on Effect of Relief Groove Angle Expressing the Position in Reducing Noise of Swash Plate Axial Piston Pump

2011 ◽  
Vol 311-313 ◽  
pp. 2215-2224 ◽  
Author(s):  
Yue Chao Song ◽  
Bing Xu ◽  
Hua Yong Yang
Keyword(s):  
Simulation Model ◽  
Optimal Shape ◽  
Piston Pump ◽  
Cylinder Pressure ◽  
Axial Piston Pump ◽  
Flow Ripple ◽  
Swash Plate ◽  
Relief Groove ◽  
Axial Piston ◽  
Important Structure

The objective of this paper is to study on the effect of the relief groove angle expressing the position in reducing noise of a swash plate axial piston pump. The relief groove is an important structure for reducing noise. Unfortunately the effect of the position of the relief groove is quite seldom explained in research reports. This paper focuses to this problem. A detail simulation model including the structure and position of the relief groove as well as the compressibility of oil film is built. The optimal shape of the relief groove is obtained by analyzing the flow ripple and cylinder pressure of the piston pump with the different shape of the relief groove on the port plate. The effect of the relief groove position and different structures on noise reducing is found by analyzing the flow ripple, cylinder pressure, sizes of relief groove and its location in different positions on the port plate. In this way the influences of the relief groove on reducing noise are found and the optimization of relief groove is obtained.

Research on the Dynamics and Variable Characteristics of a Double-Swash-Plate Hydraulic Axial Piston Pump With Port Valves

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Pengcheng Qian ◽  
Zengqi Ji ◽  
Bihai Zhu
Keyword(s):  
Rotational Speed ◽  
Flow Distribution ◽  
Variable Method ◽  
Piston Pump ◽  
Axial Piston Pump ◽  
Working Pressure ◽  
Swash Plate ◽  
Working Principle ◽  
Hydraulic Axial Piston Pump ◽  
Axial Piston

Axial piston pumps with port valves are widely used in applications that require high pressure and high power. In the present research, a new type of double-swash-plate hydraulic axial piston pump (DSPHAPP) with port valves is presented. The structure and working principle of the pump are discussed, and the balance characteristics of the pump are analyzed. A mathematical model of the pump flow distribution mechanism considering the leakage is established, based on which the effects of centrifugal forces acting on the port valves, working pressure, and rotational speed on the flow distribution characteristics are studied. A new method of varying the displacement of the pump that changes the phase relation of the two swash plates is proposed, and the principle and regulating characteristics of the variable method are studied. A detailed analysis of the forces and moments acting on the cylinder and the bearing reaction forces is presented. Finally, the relationship between volumetric efficiency and working pressure, and rotational speed and variable angle, is presented. It is revealed through an analysis that the working principle of the pump is feasible, and that the variable method can meet the requirements of varying the displacement of the pump. The characteristics of static balance and dynamic balance of the double-swashplate pump have the advantage of reducing vibration and noise. The research results also show that the reasonable matching of the working pressure and rotational speed can increase the pump's working performance to its optimum level.

The influence of dynamic swash plate vibration on outlet flow ripple in constant power variable-displacement piston pump

2019 ◽  
Vol 233 (14) ◽  
pp. 4914-4933 ◽  
Author(s):  
Yang Pan ◽  
Yibo Li ◽  
Dedong Liang
Keyword(s):  
Theoretical Model ◽  
Piston Pump ◽  
Plate Vibration ◽  
Axial Piston Pump ◽  
Constant Power ◽  
Flow Ripple ◽  
Swash Plate ◽  
Variable Displacement ◽  
Outlet Flow ◽  
Axial Piston

The vibration of a swash plate is caused by the piston forces and the control actuator acting on the swash plate. An earlier study of the outlet flow ripple of variable-displacement axial piston pumps assumed a fixed swash plate angle; it ignored the influence of swash plate vibration on the outlet flow ripple of the axial piston pump. In this work, a theoretical model of the outlet flow ripple and pressure pulsation was established in a constant power variable-displacement piston pump. The vibration of swash plate, flow leakage, and valve dynamic characteristics are considered in the theoretical model. The computational results of the theoretical model at different external load pressures are verified by comparison with experimental results. The vibration of the swash plate is strongly influenced by both the piston chamber pressure variation and the control actuator mechanism. The study proved the influence of the swash plate vibration on the outlet flow ripple and the pressure pulsation of an axial piston pump. Compared to the case of a fixed swash plate angle, accounting for swash plate vibration is much more suitable for the accurate determination of the outlet flow ripple and pressure pulsation of an axial piston pump. It is also shown that the vibration of the swash plate affects the valve plate design. Accordingly, valve plate optimization based on the theoretical model of the outlet flow ripple was also studied in this work. The amplitude of the instantaneous outlet flow ripple was considered as the optimization objective function. Finally, the optimized design parameters for a constant power variable-displacement swash plate axial piston pump were evaluated.

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.

A CFD Approach for the Simulation of an Entire Swash-Plate Axial Piston Pump Under Dynamic Operating Conditions

2020 ◽  
Author(s):  
Massimo Milani ◽  
Luca Montorsi ◽  
Gabriele Muzzioli ◽  
Andrea Lucchi
Keyword(s):  
Fluid Dynamic ◽  
Operating Conditions ◽  
Piston Pump ◽  
Axial Piston Pump ◽  
Real Component ◽  
The Real ◽  
Flow Ripple ◽  
Swash Plate ◽  
Sliding Interfaces ◽  
Axial Piston

Abstract The paper proposes a CFD approach for the simulation of a swash-plate axial piston pump including the full 3D geometry of the real component. Different meshing techniques are integrated in order to reproduce all the internal motions of the pump. The overset mesh procedure is used to simulate the dynamic evolution in regions’ shape and the variable orientation between parts in the piston-slipper ball joints while the alternating motion of the piston is accounted for by sliding interfaces with the neighboring regions. The multiple dynamics of the different moving elements are implemented in terms of superposing motions in order to reproduce the real position time histories as a function of the rotational speed and the swash plate inclination angle. The proposed numerical model includes all the leakages that characterize the coupling of the many components of the pump and nominal values are assumed (i.e. 10μm) throughout the entire simulation. A pressure-dependent fluid density approach is adopted to improve the performance prediction of the pump under real operating conditions. Moreover, the turbulent behavior of the flow is addressed by means of the two equation k-omega SST model. Therefore the proposed modeling approach highlights the capabilities to address any type of swash-plate axial piston pump in order to simulate the entire machine under dynamic operations; the numerical results are discussed in terms of flow ripple, pressure distribution and fluid-dynamic forces.

Modelling of the Micro Lubricating Gap Geometry Between Valve Plate and Cylinder Block in an Axial Piston Pump

2020 ◽  
Author(s):  
Zhiqiang Zhang ◽  
Haitao Yuan ◽  
Jianli Song ◽  
Haibo Zhou
Keyword(s):  
Wedge Angle ◽  
Valve Plate ◽  
Cylinder Block ◽  
Test Results ◽  
Axial Piston Pump ◽  
Balance Equations ◽  
Working Pressure ◽  
Displacement Sensors ◽  
Swash Plate ◽  
Axial Piston

The paper focuses on the effect of force and torque balance (FTB) of cylinder block, coaxiality error (CE) between main shaft and cylinder block, and other factors, especially eccentric wear (OTEW) of valve plate on wedge angle of the micro lubricating gap between valve plate and cylinder block, and a novel trigonometric function model of the gap geometry and mechanical balance equations of cylinder block are proposed. The three eddy current displacement sensors are used to measure the gap thickness. The results show that, the theoretical wedge angle due to FTB is nearly 1.2E-4, the test wedge angle owing to CE 1.65E-4~4.3E-4, the wedge angle by OTEW about 1.35E-3, therefore, CE and OTEW have a larger impact on the wedge angle. The test results demonstrate the total wedge angle obviously increases with the enlargement of swash plate angle but slightly rises with the increasing working pressure.

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