Special gear unit

Process for the preferably machining processing of workpieces for attainment of unround inner and/or outer contours, as the case may be eccentric arranged round boreholes and/or projections, wherein the workpiece to be processed rotates with constant angular speed about its fixed location axis, while the work tool at its contact point with the workpiece without itself rotating is driven on a circular path axially orbiting, which is tangential to the inner circle of the contour to be produced and is tangential to the circumference from the inside and of which the middle point is exactly in the middle between the inner circumference and outer circumference lying, wherein the rotational speed of the workpiece and the orbiting speed of the work tool are dependent in their path upon each other and the path speed of the work tool during its orbit is so changed, that by the fixed position rotation of the workpiece and the temporal position of the work tool on its circular path produces the desired form shape, thereby characterized, that the desired form shape is produced in multiple processing steps, wherein the work tool after each processing step with a fixed amount is advanced radially against the surface being processed and this cycle is so often repeated until the final measurement is achieved.