Lobe pumps are probably the most popular for their use in root-type superchargers, but they can also pump water. [Let’s Print] It displays through a 3D-printed design that can pump them to the best of their ability.
The design uses two figure-eight counter-rotating rotors or lobes. As the rotors rotate, they trap fluid between the rotor and the housing, forcing it toward the outlet. This is a positive-displacement design, meaning it holds a certain amount of fluid in each rotation, taking it from the creek to the outlet.
The design requires precise timing of the two rotating lobes so that they maintain a closed volume and do not affect each other. This is achieved with a pair of timing gears on the back of the pump. The housing, lobes and gears are all 3D-printed, making it a build that anyone can replicate at home with their own printer.
ABS was used for rotors to better manage friction when not easily melted. However, resin-printed lobes were also employed for their superior tolerance, both designs work acceptablely in practice.
The pump still needs further improvement; The hope is to reduce the leakage from the back of the pump. [Let’s Print] Also wants to add a motor to the pump instead of using a power drill to run the device. It’s nice to see these 3D-printed pumps running smoothly Video after the break.