Patent ID: 8231418

Claim:
A marine vessel propulsion unit arranged to apply a propulsive force to a hull, the marine vessel propulsion unit comprising: an engine; a drive shaft arranged to extend vertically; a propeller shaft arranged to extend in a direction intersecting the drive shaft and arranged such that a rotation of the engine is transmitted to the propeller shaft via the drive shaft; a propeller arranged to rotate together with the propeller shaft; a planetary gear mechanism arranged toward a front of the marine vessel propulsion unit relative to the drive shaft and coaxial to a central rotation axis of the propeller shaft and arranged to decelerate a rotation from the drive shaft and transmit a decelerated rotation toward the propeller shaft when the hull is driven forward; and a housing arranged to house the planetary gear mechanism; wherein the planetary gear mechanism includes a sun gear fixed to the housing in a non-rotating state with respect to the housing, a ring gear into which the rotation from the drive shaft is input, a plurality of planetary gears arranged between the sun gear and the ring gear, and a carrier arranged to hold the plurality of planetary gears, and the planetary gear mechanism is arranged such that a rotation of the carrier is output to the propeller shaft.