Leakage and Groove Pressure of an Axial Piston Pump Slipper with Multiple Lands

Abstract

This article presents a new analytical model, based onReynolds equation of lubrication, to evaluate the leakage and pressure distribution for an axial piston pump slipper taking into account the effect of nonvented grooves. The equations consider slipper spin and tilt and are extended to be used for a generic slipper with any number of grooves. A test rig has been designed and used to check experimentally the applicability of the theoretical equations and comparisons between theoretical and experimental results show a good agreement. The new theory can predict slipper leakage and pressure inside the groove with a high level of accuracy, especially at the very low slipper tilts that exist in practice. Experimentally, it is demonstrated that although a groove maintains a constant pressure along its path, under abnormal conditions the pressure differential can exist inside the groove. The effect of tangential velocity on groove pressure and slipper leakage is then studied experimentally, showing that as the rotational speed increases, there is a small decrease in leakage and a small increase in the average pressure inside the groove.

Prediction of Slipper Pressure Distribution and Leakage Behaviour in Axial Piston Pumps Using ANN and MGGP

“…In the ANN model, however, two layers were used. The neuron numbers in the hidden layers (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) and the activation functions in (3)-(5) were tried, in all combinations. The model with the lowest MSE (2.6558e-05) had 16 and 13 neurons in the first and second hidden layers, respectively, and incorporated the tansig activation function.…”

“…Many studies on slipper behaviour modelling have been performed in the past 40 years, in which theoretical, analytical, numerical, and machine learning methods (MLMs) have been employed with the aim of improving APP performance. Considering the tilt, grooves, and rotational speed of the slipper and swash plate, Bergada et al [1] developed new equations based on the Reynolds lubrication equation. In their model, the flow was considered to be dominant in the radial course and the fluid was taken to be incompressible.…”

Axial piston pump grooved slipper analysis by CFD simulation of three-dimensional NVS equation in cylindrical coordinates

“…The position of the grooves cut on slippers has never been studied before, although from the equations presented in [25,40] the effect of groove width and position could be analysed. In what follows it will be demonstrated that grove position and groove dimensions modify substantially the leakage across the slipper, force over the slipper will also suffer a huge modification.…”

“…Analytical solution for slippers with multiple lands was outlined in [23,24] and more clearly defined in [25], although the effect of tangential velocity was not considered. Johnson and Manring [26] developed an analytical model based on classical lubrication theory for the gap slipper-plate which takes into account the effect of tangential velocity, although the slipper considered has no groove.…”

Prediction of Leakage from an Axial Piston Pump Slipper with Circular Dimples Using Deep Neural Networks

“…A multitude of studies on the surface of hydrodynamic and hydrostatic bearings have been conducted over the past 30 years, including analytical, experimental, numerical, and artificial intelligence investigations. For example, Koç et al [2,3] proposed that the slipper should have a small convex surface to enable successful performance, whereas Bergada et al [4,5] conducted an analytical study to understand the lifting property and leakage of a slipper containing a number of grooves. These grooves on the slipper change the pressure distribution, leakage, and lifting force acting on the slipper.…”