Intermediate shaft thrust balance

Gearing system comprising:

• a first shaft having a double helical gear set comprising a first gear and a second gear, the helix angles of said first and second gears being opposite and unequal;
• a second shaft having:
• (1) a double helical gear set comprising a third gear meshing with said first gear, and a fourth gear meshing with said second gear;
• and (2) a single helical fifth gear;
• said third and fourth gears being of opposite and unequal helix angles and having substantially equal face widths, thereby resulting in substantially equal tangential face loading;
• a third shaft having a single helical sixth gear meshing with said fifth gear;
• said second shaft constituting an intermediate shaft between said first and third shafts;
• the inequality between the helix angles of said third and fourth gears, when the gears are substantially equally loaded, producing a first axial thrust on said second shaft;
• the helix angle of said fifth gear producing a second axial thrust on said second shaft opposite and substantially equal to said first axial thrust;
• the meshing of said double helical gear sets substantially locking said second shaft against axial motion relative to said first shaft;
• the substantial equalizing of said axial thrusts obviating the need for thrust bearings on said second shaft.