Marine drive lower unit with thrust bearing rotation control

Abstract From the Canadian patent

A marine drive unit includes a lower gear case forming a torpedo housing . A pair of coaxial propeller shafts are rotatably mounted in the housing and carry a pair of propellers thereon. The propeller shafts are driven by a pair of opposed driving gears suitably connected through a generally vertical main drive shaft to a marine engine and mounted on the horizontal drive axis . A pair of thrust bearings adapted to carry forward thrust loads are respectively disposed adjacent the facing portions of the opposed driving gears, with the pair being separated by a spacer tightly confined therebetween. The spacer is locked against rotation but is freely floatable in an axial direction, and …