Apparatus and method for manufacturing thick-walled hollow wheels having an internal gear toothing

A method for manufacturing a hollow wheel having an internal gear toothing defined by gear teeth that are spaced from one another by a tooth gap, comprising the steps of:

• providing a work-piece, said work-piece comprising a tubular section with a longitudinal axis;
• providing N stamping tools, wherein N is an integer that is greater than or equal to 2;
• processing the work-piece with the stamping tools by bringing each of the stamping tools into a working position to produce the gear toothing on an inside surface of the tubular section;
• wherein said processing includes the steps of:
• rotating the work-piece about the longitudinal axis at a variable speed, wherein a rotating speed of the work-piece varies over time to produce successive phases of relatively higher rotating speeds and relatively lower rotating speeds, and the processing of the work-piece by the stamping tools takes place during the phases of relatively lower rotating speed;
• moving at least one of said N stamping tools, which is in the working position, radially toward and away from the inside surface of the tubular section so that said at least one stamping tool in the working position repeatedly processes the work-piece, wherein said at least one stamping tool engages the inside of the tubular section when said work-piece is at the relatively lower rotary speed.