TRANSMISSION GEAR ASSEMBLY WITH A BREATHER CAVITY

The invention relates to a transmission gear assembly (1) comprising a housing (2) with an axial center line (7), the housing having a front wall (3) and a circumferential wall (4) with a breather opening (8,16). The front wall (3) comprises an annular groove (15) that is in fluid communication with the breather opening (8,16) and that is covered by a substantially circular plate (20) having a perimeter (21) at a first distance (r) from the axial center line (7) and with a predetermined length L. On each transverse side of the axial center line (7) in at least the lower part (19), an air/oil inlet and outlet (25,26) is defined by a recess of the perimeter (21) at a distance (r,r) from the axial center (7) line that is smaller than the first distance r, each recess having a circumferential length (l,l) and being in fluid communication with the annular groove (15). On each transverse side of the axial center line (7) in the upper part (17), an air/oil inlet (23,24) is formed by a recess of the perimeter (21) at a distance (r,r) from the axial center line (7) that is smaller than the first distance r and having a circumferential length (l,l) that is shorter than the circumferential length (l,l) of the inlet/outlets (25,26).