Steerable Gearcase With Stationary Powerhead For Marine Drives
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing outboard motor designs face challenges with interference and handling issues due to larger powerheads, limited transom mounting space, and the need for efficient cooling water and exhaust gas conveyance during steering movements.
Innovation Solution
The outboard motor configuration features a stationary powerhead with a steerable gearcase and rudder, allowing for closer mounting to the transom and improved handling. This design includes a novel steering housing and steering mechanism that facilitates efficient conveyance of cooling water and exhaust gas through concentric conduits that rotate with the gearcase.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the powerhead is made larger to provide more power, then the power output is improved, but the transom mounting space is insufficient and interference occurs between multiple motors
Solution Approach 1:
The outboard motor is divided into two separate functional units: a stationary powerhead assembly and a steerable gearcase assembly. This segmentation allows the powerhead to remain fixed on the transom while the gearcase can be steered independently, enabling closer mounting to the transom and reducing interference between multiple motors.
Solution Approach 2:
A steering housing with concentric conduits acts as an intermediary structure between the stationary powerhead and the steerable gearcase. This intermediary component facilitates the conveyance of cooling water and exhaust gas while enabling the gearcase to rotate independently, solving the space constraint problem.
2Ease of operation
If the gearcase is made steerable to improve handling, then the handling performance is improved, but the conveyance of cooling water and exhaust gas becomes complex
Solution Approach 1:
The steering housing contains concentric conduits nested within each other - cooling water conduits and exhaust gas conduits are arranged concentrically around the steering axis. This nesting arrangement allows multiple fluid conveyance functions to be integrated within a single compact structure that rotates with the gearcase, maintaining simplicity despite the steerable configuration.
Solution Approach 2:
The steering housing serves multiple functions simultaneously: it provides the steering mechanism for the gearcase, contains the cooling water conveyance system, and houses the exhaust gas conveyance system. This multi-functionality reduces overall device complexity by combining what would otherwise be separate components into a single integrated unit.
3Area of stationary object
If the powerhead is mounted closer to the transom to reduce interference, then the mounting compactness is improved, but the powerhead motion during steering increases interference
Solution Approach 1:
Instead of making the powerhead steerable (which would cause interference), the invention inverts the approach by making the gearcase steerable while keeping the powerhead stationary. This inversion allows the powerhead to remain fixed close to the transom without causing interference, as only the gearcase rotates during steering operations.
Data Source
AI summary
A marine drive comprising a powerhead that causes rotation of a driveshaft, a gearcase that supports a propulsor for propelling the marine drive in a body of water, a steering housing disposed between the powerhead and the gearcase, wherein the driveshaft or an extension thereof extends through the steering housing is operatively coupled to the propulsor, and a steering mechanism configured to steer the gearcase about a steering axis relative to the steering housing. The gearcase and steering housing are connected at a steering joint through which at least one of cooling water from the body of water is conveyed to the powerhead throughout steering movement of the gearcase and exhaust from the powerhead is conveyed to the body of water throughout steering movement of the gearcase.