Breakaway Shaft

摘要

A drive pod of a watercraft such as a boat may be designed to break off the hull of the boat in the event of an underwater collision involving the drive pod. A shaft assembly that transmits power from the engine in the hull to blades or a jet in the drive pod is designed to break at a precise point so that seals in the hull and seals in the drive pod are protected from damage. The shaft assembly may include an axial blind hole with an undercut at a bottom of the blind hole. A pin may be inserted to reinforce the shaft above the undercut.

主权项

1. A drive pod for use in a marine craft propulsion system, the drive pod comprising:
a housing configured for through-hull coupling to an engine; a gearbox; and a shaft coupled between the gearbox and the engine, the shaft including:
a spline portion disposed at a first end of the shaft;a shank portion at a second end of the shaft distal to the first end;a connecting portion adjacent to the spline portion;a blind hole disposed axially in the first end that extends to a first depth through the spline portion;a thinned portion axially aligned with a lower extent of the blind hole, the thinned portion having an axial cross-sectional area that is smaller than a cross-sectional area of the spline portion;a gear portion between the spline portion and the shank portion; and a pin disposed in the blind hole to a second depth from the first end, the second depth less than the first depth.