Rotary Vane Air Motors: Vane Shape?

[bpcash]

Can anyone tell me why the vanes in rotary vane-type air motors are curved on the bottom? I've been tasked with re-evaluating the design of some of our motors.

 

[hydtools]

To match the curved pocket in the rotor they fit into. The pocket in the rotor is cut using a rotary cutter like a slitter saw.

Or they are parted off a round bar and then only three sides need to be straight and square.

Or both.

Or ask your original designers if they are still around.

Ted

 

[bpcash]

Thanks. That could be what's confusing me. Our slots are square; I believe we are having them machined by EDM.

 

[budt]

The Vanes could be extruded duble width and then machined by sawing or milling into separate vanes. That would allow for the end that rides the cam ring to have sharp edges for sealing or the rounded end for line contact.


Bud Trinkel, Fluid Power Consultant
HYDRA-PNEU CONSULTING

 

[bpcash]

Another vane design I have come across has chamfered ends on the bottom instead of a curved profile. I would think this sort of feature would serve some function.

 

[automatic2]

vanes may be activated by inlet air pressure to extend them against the housing. A chamfered/rounded profile may be intended to allow better flow from the pressurizing port.