Shaft coupling for outboard motor

An outboard motor comprising an internal combustion engine, the engine including an engine body and an output shaft, the engine body defining a first aperture through which the output shaft extends, the output shaft having a recessed portion, the recessed portion defining inner splines, a support member supporting the engine body, the support member defining a second aperture, a driveshaft extending through the second aperture toward the recessed portion, the driveshaft having a tip portion defining outer splines, the outer splines being coupled with the inner splines so that the driveshaft is rotatably connected to the output shaft, a first seal member disposed between an outer surface of the output shaft and an inner surface of the first aperture, a second seal member disposed between an outer surface of the driveshaft and an inner surface the second aperture, the engine body, the support member, the output shaft, the driveshaft and the first and second seal members together defining a lubricant chamber to enclose lubricant, and a third seal member disposed between an outer surface of the driveshaft and an inner surface of the recessed portion, the third seal member dividing the lubricant chamber into a first space defined in the recessed portion and a second space defined at least in part out of the recessed portion.

An outboard motor comprising an internal combustion engine, the engine including an engine body and an output shaft, the engine body defining a first aperture through which the output shaft extends and is journaled, the output shaft having a recessed portion, the recessed portion defining inner spline grooves, an exhaust system arranged to discharge exhaust gases from the engine, an exhaust guide member defining a portion of the exhaust system and supporting the engine body, the exhaust guide member defining a second aperture, a driveshaft extending through the second aperture toward the recessed portion, the driveshaft having a tip portion defining outer spline grooves, the outer spline grooves being coupled with the inner spline grooves so that the driveshaft is connected to the output shaft for rotation together with the output shaft, means for trapping lubricant at least in a space between the inner and outer spline grooves, and means for supply lubricant to the space between the wire and outer spline grooves, the means for supply lubricant having a lubricant supply port that is accessible while the engine body is supported by the exhaust guide.

A shaft coupling for an internal combustion engine comprising an engine body, an output shaft extending through an aperture defined in the engine body, a driven shaft driven by the output shaft, a coupling member adapted to couple the engine body to a housing of the driven shaft, the coupling member being fluid-tightly affixed to the engine body, the driven shaft extending through a through-hole defined in the coupling member to be coupled with the output shaft, a first seal arranged to seal between the engine body and the output shaft, and a second seal arranged to seal between the coupling member and the driven shaft, the second seal having a base portion and a pair of seal portions bifurcated from the base portion, the seal portions abutting on the outer surface of the driven shaft, and the engine body, the output shaft, the coupling member, the driven shaft and the first and second seals together defining a lubricant chamber, at least one of the engine body and the coupling member defining a lubricant supply passage opening externally and communicating with the lubricant chamber.

A shaft coupling for an internal combustion engine comprising an engine body, an output shaft extending through an aperture defined in the engine body, a driven shaft driven by the output shaft, a coupling member adapted to couple the engine body to a housing of the driven shaft, the coupling member being fluid-tightly affixed to the engine body, the driven shaft extending through a through-hole defined in the coupling member to be coupled with the output shaft, a first seal arranged to seal between the engine body and the output shaft, a second seal arranged to seal between the coupling member and the driven shaft, the second seal having a base portion and a pair of seal portions bifurcated from the base portion, the seal portions abutting on the outer surface of the driven shaft, and the engine body, the output shaft, the coupling member, the driven shaft and the first and second seals together defining a lubricant chamber, and a third seal arranged to seal between the output shaft and the driven shaft and to divide the lubricant chamber into at least two chamber sections.

An outboard motor comprising an internal combustion engine, the engine including an engine body and an output shaft, the engine body defining a first aperture through which the output shaft extends, the output shaft having a recessed portion, the recessed portion defining inner splines, a support member that supports the engine body and that defines a second aperture, a driveshaft extending through the second aperture toward the recessed portion, the driveshaft having a tip portion defining outer splines, the outer splines being coupled with the inner splines so that the driveshaft is rotatably connected to the output shaft, a first seal member disposed between an outer surface of the output shaft and an inner surface of the first aperture, and a second seal member disposed between an outer surface of the driveshaft and an inner surface the second aperture, the engine body, the support member, the output shaft, the driveshaft and the first and second seal members together defining a lubricant chamber to enclose lubricant, at least one of the support member and the engine body forming a lubricant supply passage communicating with the lubricant chamber, and the supply passage having a lubricant supply port accessible when the support member supports the engine.