Outboard drive for a boat

Claim 2

The combination according to claim 1 further characterized in that said first drive shaft comprises a torsionally deflectable portion between its said upper end and the respective gear wheel thereon.

Claim 3

The combination according to claim 1 wherein said one of said gear wheels is disposed on said auxiliary drive shaft.

Claim 4

The combination according to claim 1 wherein said one of said gear wheels is adjustable on its respective drive shaft by means for temporarily introducing a film of liquid under high pressure between such gear wheel and shaft for thereby expanding the internal diameter of the gear wheel to free it for rotative movement with respect to its shaft.

Claim 5

An outboard boat drive assembly comprising a housing, an upstanding main drive shaft means in said housing including an upper drive shaft end comprising a drive attachment for drive means for the assembly and said drive shaft means further including an intermediate position and a rigid shaft portion extending downwardly from said intermediate position to a lower end, said shaft means between said intermediate position and said drive attachment comprising a torsion shaft, an auxiliary shaft including a rigid shaft portion disposed in side-by-side relation to said rigid shaft portion of said main drive shaft means, said housing having a lower end portion with a generally horizontal propeller shaft therein and extending therefrom, a propeller on said propeller shaft exteriorly of said housing, a double bevel gear keyed on said propeller shaft interiorly of said lower end portion of said housing, said auxiliary shaft having a lower end, a respective bevel gear on each said lower end, each said bevel gear being entrained with said double bevel gear, a pair of gear wheels in side-by-side close meshing engagement with substantially zero clearance between their engaged teeth, attachment means fixing one of said gear wheels on said rigid shaft portion at said intermediate position and second attachment means fixing the other of said gear wheels on said rigid shaft portion of said auxiliary shaft spacedly above said lower end thereof, one of said attachment means being releasable and the gear wheel which is fixed thereby being fixed in the position on its respective rigid shaft portion which such gear wheel assumes when, with its said attachment means released and with said propeller shaft restrained against rotation, torque equal to one-half of full load torque is applied in the respective forward drive direction to each said rigid shaft portion at or above the position of the said gear wheel thereon.

Claim 6

The combination in accord with claim 6 wherein said rigid shaft portions are offset from each other in a direction parallel to said propeller shaft, a respective long roller bearing is provided for each said rigid shaft portion in said housing immediately adjacent the bevel gear thereon, and said housing comprises an exterior anti-cavitation plate disposed below said gear wheels and spacedly above said bevel gears, and wherein that portion of said housing which is below said anti-cavitation plate is of thin walled construction closely conforming internally to the sides of said bevel gears and said double bevel gear, of said long roller bearings, and of said rigid shfat portions.

Claim 7

In a outboard drive for a boat comprising a housing carrying a generally horizontal propeller shaft at its lower end and having a main drive shaft and an auxiliary drive shaft disposed in generally upright parallel relation therein, said shafts having lower ends each provided with a respective first bevel gear, said propeller shaft having a double bevel gear keyed thereto disposed between said respective first bevel gears and on its opposite sides in close mesh therewith, a respective gear wheel on each of said upright shafts spacedly above said first bevel gears, said gear wheels being in close meshing engagement with substantially zero clearance between their engaged force transmitting teeth, said main drive shaft having an upper end portion extending above its said gear wheel and being adapted to be driven at its said upper end portion, said drive shafts being substantially rigid against torque deflection throughout the portions thereof extending between their lower ends and the gear wheels thereon throughout the power range of the drive, each said drive shaft being provided with means adjacent the gear wheels thereon through which torque may be temporarily applied by external means and means for temporarily loosening one of said gear wheels on its respective drive shaft whereby upon concurrent blocking of said propeller shaft against rotation, externally applying full load torque to said drive shafts by said torque applying means in directions to tend to cause forward propeller rotation, and loosening of said one gear wheel on its shaft, the said one gear wheel becomes adjusted in position around its shaft to take up clearances between said bevel gears and to compensate for residual torque deflections in said rigid portions of said shafts so that, upon disabling of said loosening means, said gear wheels, bevel gears and drive shafts are balanced to equally divide the drive torque between said drive shafts during full load forward drive condition.