Mechanical gear transmission

A mechanical gear transmission comprising:

• a fixed support frame;
• a ring gear having an internal toothing;
• a coupling element fixed to said ring gear and coupled to said support frame so that said ring gear is coaxial to a fixed axis;
• at least one intermediate gear wheel meshing with the internal toothing of said ring gear and rotatable about a respective axis, which is parallel to said fixed axis;
• a lubricant liquid and an annular manifold, which is fixed with respect to said support frame and is designed to collect a leaked mass of said lubricant liquid;
• said annular manifold comprising at least one first annular concave portion, which surrounds said fixed axis and said intermediate gear wheel, has a concavity facing towards said coupling element or said intermediate gear wheel and houses the mass of lubricant liquid leaked from said intermediate gear wheel and/or said ring gear as a result of a centrifugal effect;
• wherein said annular manifold further comprises:
• at least one second annular concave portion suitable to receive at least part of the mass of leaked lubricant liquid;
• said second annular concave portion being radially arranged inwardly of said first annular concave portion, surrounding said fixed axis and having a concavity facing radially towards said first annular concave portion, and
• a channelling wall for intercepting and channelling said leaked lubricant liquid;
• said channelling wall being connected in a fluid-tight manner to said first annular concave portion, on one side, and to said second annular concave portion, on the opposite side, so as to channel said leaked lubricant liquid towards one or the other of said first and second annular concave portions.