> A motor could be filled with oil, but the problem of preventing oil leaks through the bearings would be insurmountable Shouldn't be too hard for stationary a

> A motor could be filled with oil, but the problem of preventing oil leaks through the bearings would be insurmountable Shouldn't be too hard for stationary applications if you stick to a vertical axis and allow gravity to help keeping oil and air separate. I guess neighbor post's viscosity counterargument will do fine in its own though.