Method of producing a rotor for a commutator machine using an angled sonotrode

A method of producing a rotor for a commutator machine, which comprises forming a rotor shaft (10), a rotor winding (14) that is contained in a rotor body (11) supported non-rotatably on the rotor shaft (10), and a commutator (12), forming an insulation material body (16) non-rotatably supported on the rotor shaft (10) and has a number of commutator lamellas (17) that are disposed extending axially parallel with such housing lamella end, next to one another on the insulation material body (16), with insulating gaps in a circumference direction, and with a connection lug (18) respectively bent at an angle of approximately 45 degrees from each of the lamella ends and is oriented axially with an inner surface (183) toward the lamella supporting the insulation material body (16) against an end face (111) of the rotor body (11) oriented toward the insulation material body, further comprising the steps of winding connection wires (15) of the rotor windings (14) around the connection lugs (18), pressing a sonotrode (20) coaxial to the rotor shaft 10 and having an annular welding surface (21′) embodied on an end face of the sonotrode concentric to commutator axis and inclined so that the inclined welding surface encloses an angle of approximately 135° with a sonotrode axis thereby extends approximately parallel to the inner surface (183) of the connection lugs (18) oriented toward the commutator lamellas (17) against the connection wires (15) and produces high-frequency mechanical rotary vibrations with the sonotrode for ultrasonically torsion welding the winding wires (15) to the connection lugs (18).