Experimental Study on the Influence of the Rotating Cylinder Block and Pistons on Churning Losses in Axial Piston Pumps

Abstract

Pressure and performance requirements of axial piston pumps and the proportion of churning losses in axial piston pumps increase significantly with increasing speed. To investigate the primary distribution of churning losses in axial piston pumps at various ranges of speed, a test rig was set up in which other friction losses can be eliminated, thus making it possible to investigate the net churning losses in an axial piston pump. The influence of the rotating cylinder block and pistons on churning losses is analyzed based on a qualitative evaluation of the various fluid flow regimes at different test speeds in an axial piston pump. The analytical results indicate that pistons have less influence on churning losses than the rotating cylinder block beyond the critical speed in axial piston pumps, because the total energy dissipation transforms laminar viscous friction losses into turbulent shear stress losses. It is concluded that more attention should be given to the effect of the rotating cylinder block on churning losses in axial piston pumps at high rotation speed.

Numerical and experimental study on the churning losses of 2D high-speed piston pumps

“…However, with the increase in the rotational speed, the energy losses of axial piston pumps significantly increase, so their efficiency is decreased (Manring, 1996;McCandlish & Dorey, 1984). The energy losses can be normally divided into three groups: mechanical losses, volumetric losses, and churning losses (Manring, 1998(Manring, , 1999He-sheng et al, 2014;Tang et al, 2016;Zhang et al, 2017).…”

“…In comparison with the well-studied mechanical and volumetric losses, studies on the churning losses in highspeed piston pumps are relatively rare. Generally, churning losses are not prominent in traditional axial piston pumps because these pumps work with a rotational speed that only ranges from 1000 to 3000 rpm (Zhang et al, 2017). In order to improve the power/weight ratio of pumps, one common method is to reduce their displacement.…”

Analysis of the Hydrodynamic Lubrication Characteristics of the External Return Spherical Bearing Pair of an Axial Piston Pump/Motor

“…Although three key friction pairs (slipper pair, flow distribution pair, and plunger pair) of axial piston pumps and motors have been extensively researched worldwide, and scholars have achieved fruitful results [1][2][3], not much research has been conducted on the pair of retainer platespherical hinge. e return mechanism is a key component of an axial piston pump or motor and has a direct effect on the performance of the three friction pairs, as it provides the preload force to the three key friction pairs to ensure the slipper clings to the swash plate as the plunger is reciprocating [4][5][6].…”

Energy Efficiency and Controllability of Fluid Power Systems

“…For this reason, significant research has been done in the last decades to study the source of the power losses within the units and possible improvements to their design. In this area, the contribution by Zhang et al [8] clarifies the mechanism of generation of churning losses, which is particularly relevant at high pump shaft speeds. Their study is supported by a test rig they purposely designed for this research.…”

“…New approaches for the analysis, modeling, and design of hydraulic and pneumatic components This book contains the successful invited submissions [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] to the Special Issue.…”