Rim-Driven Jet Propulsion Layout for Personal Watercraft Packaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The positioning of electric motors in personal watercraft affects the center of gravity, complicating assembly and packaging, and existing configurations do not optimize space utilization and weight distribution.
Innovation Solution
A rim-driven motor is positioned within a housing between the inlet and venturi of a jet propulsion system, with a stator and rotor configuration that allows for efficient water propulsion, and is externally mounted to simplify assembly and packaging, enabling better weight distribution and increased battery capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the electric motor is positioned within the interior space of the personal watercraft, then the center of gravity can be optimized, but the assembly complexity and packaging difficulty increase
Solution Approach 1:
The motor is extracted from the interior space and mounted externally on the transom or rear section of the hull. This removes the motor from the constrained interior environment, eliminating the need for complex routing of shafts, belts, or drive mechanisms through the hull structure, while still allowing strategic positioning to achieve desired center of gravity characteristics.
Solution Approach 2:
The motor positioning problem is solved by moving from a two-dimensional interior floor plan constraint to a three-dimensional external mounting solution. The motor is positioned in the vertical and longitudinal dimensions outside the hull, allowing independent optimization of center of gravity without being constrained by interior packaging boundaries.
2Stability of the object's composition
If the electric motor is positioned within the interior space, then integration is improved, but the available space for battery pack is reduced
Solution Approach 1:
The motor is extracted from the interior space and mounted externally, freeing up the entire interior volume that would have been occupied by the motor, its mounting structure, and associated drive mechanisms. This extracted space is then available for maximizing battery pack capacity and arrangement.
Solution Approach 2:
The motor mounting structure is merged with the transom or rear hull structure, creating an integrated external assembly that eliminates the need for separate interior mounting brackets and support structures, thereby preserving maximum interior volume for battery storage.
3Device complexity
If the motor is mounted externally on the housing, then assembly and packaging are simplified, but the center of gravity positioning becomes more challenging
Solution Approach 1:
The external motor mounting system is designed with adjustable positioning capabilities, allowing the motor to be mounted at different longitudinal and vertical positions on the transom. This dynamic adjustability enables optimization of center of gravity characteristics while maintaining the simplified external mounting approach.
Solution Approach 2:
The transom or rear hull structure is locally reinforced and configured with specific mounting features at strategically chosen positions. This localized structural optimization allows precise control over motor positioning and resulting center of gravity without requiring complex overall structural changes.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The rim-driven motor simplifies assembly, optimizes space utilization, and improves weight distribution by allowing for a larger battery capacity and reduced complexity, enhancing the overall performance and stability of the personal watercraft.
Implementation Method 1
the stator has circumferentially disposed thereon a plurality of windings configured to generate a magnetic flux, and the rotor comprises at least one magnetic element configured to generate a magnetic field adapted to interact with the magnetic flux to cause rotation of the rotor and of the impeller blades
Implementation Method 2
impeller blades coupled to the rotor and projecting towards the center axis, the rotor and the impeller blades being rotatable about the center axis relative to the housing to draw the water into the housing via the inlet and expel the water from the housing via the outlet
Implementation Method 3
a venturi, and an outlet to expel the water from the housing
Data Source
AI summary
A personal watercraft comprises a deck having coupled thereto a hull defining a bottom wall, a rear wall and a water intake extending from the bottom wall to the rear wall, and a jet propulsion system. The jet propulsion system comprises a housing coupled to the rear wall and defining an inlet to receive water from the water intake, a venturi, and an outlet to expel the water, and comprises a rim-driven motor disposed within the housing between the inlet and the venturi. The rim-driven motor defines a center axis and comprises a stator coupled to the housing, a rotor disposed radially inwardly of the stator relative to the center axis, and impeller blades coupled to the rotor and projecting towards the center axis, the rotor and the impeller blades rotatable about the center axis to draw the water via the inlet and expel the water via the outlet.