Boat-propulsion gravity column with hydraulic motor driving screw - uses hydraulic motor feed and return pipes connected by convex plates

摘要

The boat-propulsion column (2) incorporates an hydraulic motor (3) driving a propeller (4) and comprises flow (21) and return (22) pipes for the motor, the two pipes also contributing to the structural capability of the column. The pipes may be spaced one behind the other in the direction of forward boat movement and may be connected by convex plates. The volume between plates contains oil (27) escaping (42,43,44) from the motor, together with a lubricating feed (25).