초록 ▼

A lower unit for a marine propulsion system has a flow disrupter positioned along the side wall of the vertical strut above the torpedo gearcase. The strut has a high pressure side and low pressure side which results from the strut being positioned at an angle with respect to the direction of boat t

A lower unit for a marine propulsion system has a flow disrupter positioned along the side wall of the vertical strut above the torpedo gearcase. The strut has a high pressure side and low pressure side which results from the strut being positioned at an angle with respect to the direction of boat travel in order to compensate for steering torque. The flow disrupter is positioned on the low pressure side of the strut, and promotes the separation of water passing over the vertical strut in a controlled manner, thereby reducing steering jerks during acceleration due to dramatic hydrodynamic flow changes. The flow disrupter consists of a series of steps or textured areas positioned along the aft section of the vertical strut. In a preferred embodiment, each of the steps contains a vent passage permitting exhaust to exit the strut through the steps to further promote controlled separation of water passing over the strut.

대표청구항 ▼

[ We claim:] [1.] A lower unit for a marine propulsion system, comprising:a submerged propeller driven in one direction, the rotation of said propeller producing steering torque in a given direction;a torpedo gearcase for supporting said propeller at a position aft of said torpedo gearcase;a vertica

[ We claim:] [1.] A lower unit for a marine propulsion system, comprising:a submerged propeller driven in one direction, the rotation of said propeller producing steering torque in a given direction;a torpedo gearcase for supporting said propeller at a position aft of said torpedo gearcase;a vertical strut positioned above and formed integrally with said torpedo gearcase, said strut having a fore section and an aft section and a pair of streamlined side walls converging at an aft end of said strut; anda flow disrupter positioned on one of said pairs of side walls of said strut, such that the flow disrupter promotes separation of water passing over the side wall of the strut from laminar flow to turbulent flow, wherein said flow disrupter consists of a series of textured areas positioned on said converging strut side wall slightly above said torpedo gearcase and on the aft section of said strut.