Advantages of elliptical tip vanes on the kinematic design of balanced vane pumps

This work describes the kinematic properties achievable by using vanes with elliptical tip shapes in balanced vane pumps. The position of the contact point is analytically determined by taking advantage of the ellipse geometrical properties, which lead to a set of nonlinear algebraic and trigonometric equations. The kinematics is then linked to the main design parameters of the vane tip, allowing for the determination of the admissible domain of the vane geometry given the cam ring profile. A parametric study is then performed to highlight the potentials of this design solution, which gives additional parameters to control the pump design with respect to the classical circular tip vanes. The analysis involves also the tip eccentricity, a key parameter in the definition of the production tolerances, demonstrating the robustness of this design solution. Finally, performance indicators are defined to evaluate this aspect.