Numerical Simulation of a Slipper Model for Water Hydraulic Pumps/Motors in Mixed Lubrication

Abstract

This paper presents a time-dependent mathematical model of a hybrid (hydrostatic/hydrodynamic) thrust pad bearing as a slipper of swash-plate type axial piston pumps and motors for the use of tap water under mixed and fluid fihn lubrication condition. Effects are examined of the load eccentricity, time-lag of changes in the supply pressure and load, surface roughness, recess volume, and the revolution radius. The bearing's motion is simulated three-dimensionally, including roughness interaction and asperity contact. Solutions are obtained regarding the friction, flow rate, power loss, and stiffness. Calculations indicate that the eccentric load causes local contacts. The preceding change in the load poses a larger motion of the bearing. The hydrodynamic effect becomes marked as the revolution radius increases. As the recess volume increases, the bearing stiffness decreases.

Analysis of the flow dynamics characteristics of an axial piston pump based on the computational fluid dynamics method

“…In this way, the theoretical computation time will be 1/9 of the whole computation time based on Figure 3. In order to ensure the accuracy, the actual computation time should be a little more than the theoretical computation time (Kazama, 2005).…”

“…Flow dynamics characteristics can cause much damage to the pump, such as noise, lower volumetric efficiency, overturning of the cylinder block, cavitation, and short service life (Huang, 2004;Ma, Xu, Zhang, & Yang, 2010); therefore, the study of the pump's flow dynamics characteristics is essential. In order to study the influence of the slipper model on hydraulic pumps' flow dynamics characteristics, a time-dependent mathematical model of a hybrid trust pad bearing as a slipper of swash-plate-type axial piston pumps and motors was presented (Kazama, 2005). A hybrid trust bearing was developed as a slipper model of water hydraulic piston pumps and motors, and numerical solutions of the time-dependence problem were also built for a wide range of operations under water-lubricated conditions.…”

The hydrostatic/hydrodynamic behaviour of an axial piston pump slipper with multiple lands

“…The solution of Reynolds equation, in which radial and angular pressure distribution is taken into account, has been performed via solving the differential equation as a power series [3,6,13,14,20]. An analytical solution for slippers with multiple lands was outlined in Bergada and Watton [23][24][25] and also in Watton [26,27], another work by Bergada et al [28] considered tilt but with no tangential speed effects.…”

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

“…Most of the work has focused on analyzing the forces and torques over the slipper, experimentally, analytically and via CFD [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. The effects of slipper spin, tangential velocity, tilt, slipper non-flatness, inlet orifice, and conditions for metal to metal contact, among others, were investigated.…”