A tooth profile of an inner rotor 2 is formed by an envelope of a group of circular arcs of a locus circle C having a center on a trochoidal curve TC. The system comprises a sensor for detecting a parameter relating to the operation of the railway train. For example, each of two or more configured monitoring zones is associated with a different combinatorial zone selection pattern of asserted zone selection input signals. The angles of the conical surfaces in the connection chamber and the contact part are executed differently in this case.