Abstract: A speed reducer includes: a case, a worm disposed in a housing of the case and including a proximal portion coupled to an input shaft, a worm wheel coupled to an output shaft and arranged so as to be driven in rotation by the worm, a proximal bearing holding the proximal portion of the worm in the housing, a distal bearing holding a distal portion of the worm, the distal bearing being disposed in a cylindrical distal portion of the housing, a spring held fixed in the distal portion of the housing around the distal bearing, the spring including at least one elastic blade disposed and shaped to bear on the case and to exert forces on the distal bearing in a direction towards the worm wheel.

Abstract: A power steering case, including an opening, a lid configured to close the opening of the case, and an O-ring seal disposed in a first annular groove formed in a first inner wall of the lid or of the case, a second inner wall, respectively of the case or of the lid, having a frustoconical shaped portion for progressively compressing the seal before reaching the closed position of the lid where the seal tends to regain a less deformed initial shape in a second annular groove facing the first annular groove and formed in the second inner wall.