Planetary gear reduction mechanism in particular for motor vehicle starter and starter equipped with same

摘要

A reduction gearbox with an epicyclic gear train is provided for a motor vehicle starter. This gearbox includes a crown (30) comprising a outer crown part (31) and an inner crown part (32) carrying an internal set of teeth (33) together with shock absorbing elements (34). The the damping elements (34) are made in the form of plates disposed in seatings which consist of complementary recesses (36, 37) formed respectively in an outer peripheral face (38) of the inner crown part (32) and in an inner peripheral face (39) of the outer crown part (31). Each recess has a depth which increases in a direction of relative angular displacement between the two crown parts, considered from the peripheral surface, over a length (a) which corresponds to the length of the plate, to a value (b) which is substantially equal to the thickness of the plate.