In curves, there is a sufficient rolling circle differential, permitting less wear and tear.

In order to adapt the loading capacity of the rows of rolling bodies (10, 12) to the respective load conditions, the two rows of rolling bodies (10, 12) have different rolling circle diameters (D1, D2) respectively adapted to the highest expected load.

The radius of the third outside radius of curvature is from 0.08 to 0.1 of the rim diameter.

The radius of the fourth outside radius of curvature is from 0.07 to 0.09 of the rim diameter.

The EoC element (150, 150) thus operating as the inner rolling circle of a hypocycloid counting the numbers of relative rotations.

The worm gear teeth (4) shape is defined by manufacturing principle of rolling the rack over the rolling circle (6) of the worm gear (2).

Therefore, it is a hypotrochoid (base circle with radius , rolling circle with radius , distance from the point to the rolling circle = ), and the pedal of a deltoid with respect to its centre, like all trifolia.

For the inside surface of the disk, the radius of the first inside radius of curvature is from 0.08 to 0.1 of the rim diameter.

On the outside surface of the disk of the railway wheel, the radii of the first and second outside radii of curvature are from 0.04 to 0.05 of the rim diameter.

A plate (17) carrying food (19) to be cooked rests on a roller ring (18) and engages the shaft of a motor (16).

The arches meet at cuspidal points, obtained for , located on the rolling circle, at altitude 0, and their vertices are located on the circle at altitude , with radius .