Patent ID: 8157694
Filing Date: 2012-04-17
Classification: B63H,F16H

Abstract:
1. An outboard motor comprising: a power transmission mechanism arranged to transmit power of an engine to a propeller, the power transmission mechanism including: when the on-off clutch is disengaged, the one-way clutch is engaged and the gear train output is driven at a rotational speed that is less than a rotational speed of the first output shaft of the engine; when the on-off clutch is engaged, the one-way clutch is disengaged and the gear train output is driven at the same rotational speed as the rotational speed of the first output shaft of the engine; the transmission ratio changing unit includes a second planetary gear train disposed below the first planetary gear train and including a second sun gear, second double planetary gears, and a second internal gear, the second double planetary gears are connected to the gear train output, and the second sun gear is connected to a second output shaft that is arranged to communicate rotation to the propeller, the second internal gear is connected to a stationary portion via a reverse clutch, and the second double planetary gears are connected by a forward clutch to at least one of the second internal gear and the second sun gear; when the forward clutch is engaged with the reverse clutch disengaged, the second sun gear, the second double planetary gears, and the second internal gear rotate together to cause the first planetary gears of the first planetary gear train and the second sun gear of the second planetary gear train to rotate in the same direction at the same speed to establish a forward drive state; when the forward clutch and the reverse clutch are disengaged, each of the second sun gear, the second double planetary gears, and the second internal gear rotates freely so that a rotational speed of the second output shaft at the second sun gear is substantially zero to establish a neutral state; and when the forward clutch is disengaged with the reverse clutch engaged, the second internal gear is brought into a fixed state and the second double planetary gears and the second sun gear rotate to cause the first planetary gears of the first planetary gear train and the second sun gear of the second planetary gear train to rotate in opposite directions so as to establish a reverse state.