 Helical symmetry of a potential

A potential $V(r,\varphi ,z)=f(r,\varphi -kz)$ is invariant under the screw transformation $(\varphi ,z)\mapsto (\varphi +ks,z+s)$. The Noether conserved quantity for a mechanical point symmetry isa linear combination of axial linear momentum and axial angular momentum.