TWO-SPEED AUTOMATIC TRANSMISSION FOR A MARINE PROPULSION DEVICE

摘要

Disclosed herein is a marine propulsion device including an input shaft drivingly connected to a power source, a lower unit having a rotatably mounted drive shaft extending in coaxial relation to the input shaft, and a propeller shaft rotatably mounted in the lower unit, the propeller shaft carrying a propeller. A two-speed transmission is provided to drivingly connect the input shaft to the drive shaft, the transmission including a first drive arrangement between the input shaft and the drive shaft for selectively drivingly connecting the input shaft and the drive shaft, the first drive arrangement including a third shaft rotatably mounted in parrallel relation to the input shaft and the drive shaft, a drive gear, a driven gear mounted on the third shaft and in meshing engagement with the drive gear, and a one-way overrunning clutch drivingly connecting the input shaft and the drive shaft through the drive and driven gears when the rotational speed of the input shaft is less than a predetermined value. The first drive arrangement has an input-output speed ratio with a first value. The transmission also includes a second drive arrangement for selectively drivingly connecting the input shaft and the drive shaft when the rotational speed of the input shaft is greater than the predetermined value, the second drive arrangement including a selectively actuatable clutch for drivingly connecting the input shaft and the drive shaft. The second drive arrangement has an input-output speed ratio with a second value greater than the first value.