Simon Leonhartsberger, Bernhard Manhartsgruber,
"Challenges in Elastohydrodynamic Simulations of Radial Ball Piston Pumps"
: Proceedings of the 2024 ASME/BATH Symposium on Fluid Power and Motion Control (FPMC2024), September 11-13, 2024, University of Bath, UK., 2024
Original Titel:
Challenges in Elastohydrodynamic Simulations of Radial Ball Piston Pumps
Sprache des Titels:
Englisch
Original Buchtitel:
Proceedings of the 2024 ASME/BATH Symposium on Fluid Power and Motion Control (FPMC2024), September 11-13, 2024, University of Bath, UK.
Original Kurzfassung:
Radial ball piston pumps use spherical pistons in contrast to the piston and slipper assemblies as utilized by common radial piston pumps. Rolling bearing balls are mass-produced and therefore relatively cheap while nonetheless, their diameter is lying in a very narrow tolerance field. Downsides to these types of pumps are the very short sealing gap length, the smallest clearance only occurs around the circumference, and the minor stroke, which is limited by the diameter of the ball. Between ball and eccentric shaft, a point contact occurs, leading to Hertzian pressure and therefore limiting the maximum pump pressure.
In order to simulate the dynamic behavior of the ball during a piston stroke multiple aspects have to be taken into account. The narrow clearance favors the use of the Reynolds equation to avoid excessive computational costs. The elastic deformation of the housing and the ball calls for an elastohydrodynamic simulation and consequently for a FEA-simulation. As the gap widens and laminar flow possibly transitions to turbulent flow a CFD-simulation has to be implemented. Ultimately the relatively high displacement and the rotation of the ball (multiple rotations per stroke) need to be taken into account.
These requirements cannot be met by a single domain software package as multiple numerical models must be united. Efficient simulations are necessary in order to fully understand the behavior of radial ball piston pumps and contribute to further improvements of this pump type. This paper evaluates selected commercial software packages in order to determine the current possibilities for feasible simulations of radial ball piston pumps.