Abstract
At the 57th European Study Group with Industry in Lyngby
2006 Grundfos asked for a mathematical analysis of the Moineau pump. The pump
was invented in 1931 by the French engineer RenŽ Moineau. It is an example of a
progressive cavity pump and exhibits an intriguing geometry. The original
design is based on hypo- and epi-cycloids and all except one design has either
cusps or inflexion points with infinite curvature. By using the support
function to represent planar curves it is possible to make an explicit analysis
of a general design and we can show that points of infinite curvature can not
be avoided.