Abstract: A transmission gear assembly including a housing with an axial center line, having a front wall and a circumferential wall with a breather opening. The front wall includes an annular groove in fluid communication with the breather opening and covered by a substantially circular plate having a perimeter at a first distance (r) from the axial center line and with a predetermined length (L). On each transverse side in at least the lower part, an air/oil inlet and outlet is defined by a recess of the perimeter at a distance (r3,r4) from the axial center line smaller than the first distance (r), each recess being in fluid communication with the annular groove. On each transverse side in the upper part, an air/oil inlet is formed by a recess of the perimeter at a distance (r1,r2) from the axial center line smaller than the first distance (r) and having a circumferential length (l1,l2) shorter than a circumferential length (l3,l4) of the inlet/outlets.

Abstract: A transmission gear assembly including a housing with an axial center line, having a front wall and a circumferential wall with a breather opening. The front wall includes an annular groove in fluid communication with the breather opening and covered by a substantially circular plate having a perimeter at a first distance (r) from the axial center line and with a predetermined length (L). On each transverse side in at least the lower part, an air/oil inlet and outlet is defined by a recess of the perimeter at a distance (r3,r4) from the axial center line smaller than the first distance (r), each recess being in fluid communication with the annular groove. On each transverse side in the upper part, an air/oil inlet is formed by a recess of the perimeter at a distance (r1,r2) from the axial center line smaller than the first distance (r) and having a circumferential length (l1,l2) shorter than a circumferential length (l3,l4) of the inlet/outlets.