Hydraulic-Mechanical Coupled Simulation of 2D Micromotion in Variable Displacement Vane Pumps for Engine Lubrication

Abstract Variable displacement vane pumps are widely used for lubrication in internal combustion engines. A key aspect concerns the contact between the vane tip and the stator, both for wear issues and for potential leakages in case of detachment. The purpose of this study is to introduce a simulation methodology based on coupling the lumped parameter hydraulic model and the multibody mechanical model. The principle underlying the method consists of calculating the forces on the moving elements in the hydraulic model and letting the multibody model calculate the displacements of the bodies. The advantage of this approach lies in the assessment of 2D micromovements resulting from clearances of the vanes relative to other mechanical components of the pump core. It allows simulating the detachment of vanes from the stator track, their tilt in the rotor slots, as well as the mutual interaction between vanes through the underneath floating rings. Simulations revealed two distinct behaviors depending on the operating conditions. At low speeds, a strong interaction between the vanes and the rings was observed. In particular, the rings are maintained in an almost constant position by the thrust of the vanes. Conversely, at high speeds, all vanes remain in constant contact with the stator track, and the rings are completely floating. The model is well-suited for enhancing pump design, given its ability to calculate the forces exchanged by the mechanical parts more realistically.