An outboard propulsion system comprising: a first portion for attachment to a boat comprising a stern, the first portion comprising an engine including a crankshaft; and a second portion comprising at least one propeller shaft having a longitudinal axis along the elongate length of the at least one propeller shaft, wherein the at least one propeller shaft is operably connected to the crankshaft via at least one drive shaft configured to transmit motive power therebetween, wherein the at least one drive shaft comprises a drop shaft and wherein the drop shaft is substantially perpendicular to the at least one propeller shaft, wherein the second portion is configured to pivot relative to the first portion about a steering axis, wherein the steering axis intersects the longitudinal axis of the at least one propeller shaft at an obtuse angle, wherein the first portion and second portion are configured to tilt together about a single axis of rotation substantially parallel to the stern of the boat, and wherein the first portion is fixed about a substantially vertical axis.

An actuator includes a drive body including a torque-transfer surface configured to receive a torque. The actuator further includes: a drivable body including an output shaft; a first bearing configured to transfer thrust forces from the output shaft in a first direction; and a second bearing configured to transfer thrust forces from the output shaft in a second direction. At least the first bearing extends in a radial dimension beyond the torque-transfer surface. The drive body may be engaged with the drivable body through at least one ball such that rotation of the drive body causes movement of the output shaft. The at least one ball may engage with the drive body over a greater extent along an axis of rotation than with the drivable body.

An actuator includes a drive body including a torque-transfer surface configured to receive a torque. The actuator further includes: a drivable body including an output shaft; a first bearing configured to transfer thrust forces from the output shaft in a first direction; and a second bearing configured to transfer thrust forces from the output shaft in a second direction. At least the first bearing extends in a radial dimension beyond the torque-transfer surface. The drive body may be engaged with the drivable body through at least one ball such that rotation of the drive body causes movement of the output shaft. The at least one ball may engage with the drive body over a greater extent along an axis of rotation than with the drivable body.

A stern drive for a marine vessel comprises a gimbal housing that is configured for connection to the transom of the marine vessel; a gimbal ring that is steerable with respect to the gimbal housing about a vertical steering axis; a drive leg that is trimmable with respect to the gimbal ring about a horizontal trim axis, wherein the drive leg supports a propulsor for propelling the marine vessel; a trim actuator that is configured to trim the drive leg about the trim axis; and a cradle that decouples the drive leg from the transom of the marine vessel and pivots with and supports the drive leg and as the trim actuator trims the drive leg about the trim axis.

A stern drive for a marine vessel comprises a gimbal housing that is configured for connection to the transom of the marine vessel; a gimbal ring that is steerable with respect to the gimbal housing about a vertical steering axis; a drive leg that is trimmable with respect to the gimbal ring about a horizontal trim axis, wherein the drive leg supports a propulsor for propelling the marine vessel; a trim actuator that is configured to trim the drive leg about the trim axis; and a cradle that decouples the drive leg from the transom of the marine vessel and pivots with and supports the drive leg and as the trim actuator trims the drive leg about the trim axis.

A marine engine propelling apparatus (10) is mounted to an outboard portion at a rear end of a boat. The engine propelling apparatus (10) has a power generating portion (13), a power transmitting portion (17) provided below the power generating portion (13), a propelling force generating portion (28) provided below the power transmitting portion (17), and a height adjustment mechanism (25). The power generating portion (13) includes an engine (11) equipped with a crankshaft (11C), and the crankshaft (11C) is arranged substantially parallel to a front-rear direction of the boat and is substantially horizontal. The power transmitting portion (17) has a power transmission mechanism forming a linear power transmission route (D2) extending from the vicinity of a front end of the crankshaft (11C) to the vicinity of a front end of the propelling force generating portion (28). The propelling force generating portion (28) includes a propeller shaft (22) extending rearwards from the power transmitting portion (17), and a propeller (27) provided at a rear portion of the propeller shaft (22). The height adjustment mechanism (25) is configured to vary inclination of a part of the propeller shaft (22) with respect to the boat to thereby vary height of the propeller (27) with respect to the boat.

A portable propulsion system for a watercraft may include a shaft, a propeller, an outer casing, and a flexible strap. The shaft may have a prop end section, a drive end section, and a rotational axis extending from the prop end section to the drive end section. The propeller may be connected to the prop end section of the shaft. The drive end section may be configured for removable connection to a driver for rotation of the propeller via rotation of the shaft about the rotational axis to propel the watercraft. The outer casing may be disposed around the shaft. The flexible strap may have first and second end sections connected to the outer casing in respective first and second regions.

An outboard motor includes a drive source, a drive shaft, a steering shaft, a case, and an angle detection sensor. The drive shaft extends in an upper-lower direction and is rotatable by the driving force of the drive source. The hollow tubular steering shaft surrounds an outer circumference of the drive shaft. The case is located lower than the drive source, and an oil chamber is structured to store oil, and at least a portion of the steering shaft is housed in the oil chamber. The angle detection sensor is located higher than the oil chamber to detect the rotation angle of the steering shaft.

An outboard motor includes a drive source, a drive shaft, a steering shaft, a case, and an angle detection sensor. The drive shaft extends in an upper-lower direction and is rotatable by the driving force of the drive source. The hollow tubular steering shaft surrounds an outer circumference of the drive shaft. The case is located lower than the drive source, and an oil chamber is structured to store oil, and at least a portion of the steering shaft is housed in the oil chamber. The angle detection sensor is located higher than the oil chamber to detect the rotation angle of the steering shaft.

An outboard motor includes a case having a gear chamber, a drive shaft arrangement hole, and a propeller shaft arrangement hole, a drive shaft, a propeller shaft, a drive gear, a driven gear, a gear position setting member provided in front of the driven gear in the case and configured to set a position of the driven gear in a front-rear direction, and a screw mechanism configured to move the gear position setting member in the front-rear direction when the gear position setting member is rotated about an axis of the gear position setting member. The screw mechanism includes a first screw provided in the case and a second screw provided on the gear position setting member and configured to be screwed with the first screw.