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

A reduction gearbox with an epicyclic gear train, especially for a motor vehicle starter, of the type including a crown which comprises an outer crown part fixed in the carcass of the starter, and an inner crown part which is mounted coaxially in the outer part and which carries an internal set of teeth in mesh with the planet wheels of the reduction gear train, together with shock-absorbing damping elements which are interposed between the abutment faces formed on the inner peripheral face of the outer crown part and the outer peripheral face of the inner crown part, characterised in that the damping elements (34) are made in the form of plates disposed in seatings which consist of recesses (36, 37) of complementary form, formed respectively in the outer peripheral face (38) of the inner crown part (32) and in the inner peripheral face (39) of the outer crown part (31), each recess having 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.