Influence of rotor profile geometry on the performance of an original low-pressure gerotor pump

• Novel design concept for gerotor pump featuring radial ports is introduced and discussed.
• Theoretical analysis on the influence of rotors profiles on pump performance is needed.
• Considered geometries for lobes profiles are: traditional circular, narrow and enlarged ellipse.
• Benefits and issues of each solution are presented and discussed.
• Asymmetric lobe concept is introduced and its merits assessed.

Gerotor pumps are a common choice for low-pressure fluid systems, such as fuel or lubricating oil distribution. Starting from a patented solution, gerotor devices featuring radial ports are presented and discussed: major sizing constraints due to low-pressure operation are defined and their influence over rotor profile geometry assessed. In order to maximize the pump displacement, a comparison between several profile geometries is set up: circular, elliptic and asymmetric lobes are presented and mathematically described using a simple unified approach, while the comparison indexes are defined and discussed. Pros and cons of each geometry type are finally assessed.