Watercraft Jet Actuator Sealing for Electronic Gate Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing watercraft jet propulsion systems lack an efficient and electronically controllable actuator for the reverse gate, which is crucial for directional control and braking, relying on manual activation through cables and linkages.
Innovation Solution
A gate actuator assembly with a sealing member, such as a bellows, that forms a variable volume outer chamber to prevent fluid ingress and includes an actuator arm connected to a position sensor, allowing electronic control of the gate's pivoting mechanism within the engine compartment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If a manual actuation system with cables and linkages is used, then the structure is simple, but electronic control capability is lost
Solution Approach 1:
The patent replaces the traditional manual mechanical actuation system (cables and linkages) with an electronic actuator assembly that uses an electric motor to drive a gear mechanism. This substitution enables electronic control capability while maintaining mechanical actuation of the gate, resolving the contradiction between automation and complexity by introducing controlled complexity only where needed for electronic operation.
Solution Approach 2:
The patent introduces an intermediary actuator assembly between the electronic control system and the gate mechanism. This intermediary component translates electronic signals into mechanical motion through a motor-gear linkage, serving as a mediator that enables electronic control without directly exposing the gate mechanism to complex electronic components, thus balancing automation with manageable complexity.
2Reliability
If the actuator is exposed to the engine compartment environment, then assembly is convenient, but fluid ingress damages components
Solution Approach 1:
The patent employs a flexible bellows-shaped sealing member that encloses the actuator arm and forms a protective chamber. This flexible shell structure provides reliable protection from fluid ingress while accommodating the linear motion of the actuator arm through its flexible walls, resolving the contradiction by using a simple yet effective flexible sealing mechanism rather than complex rigid seals.
Solution Approach 2:
The patent segments the sealing function from the actuator housing by using a separate bellows-shaped sealing member that can independently perform the sealing function. This segmentation allows the sealing mechanism to be optimized for protection while remaining mechanically simple, as the bellows structure independently handles fluid exclusion without requiring complex integrated sealing systems.
3Reliability
If a sealed chamber is formed around the actuator arm, then component protection is improved, but the actuator arm motion is constrained
Solution Approach 1:
The patent uses a flexible bellows-shaped sealing member that encloses the actuator arm but allows it to move linearly along its axis. The flexible walls of the bellows expand and contract with the actuator arm's motion while maintaining the sealed chamber, thus providing protection from fluid ingress without constraining the actuator arm's operational motion, resolving the contradiction between sealing and mobility.
Solution Approach 2:
The patent employs a dynamic sealing structure where the bellows-shaped chamber can change its volume and shape in response to the actuator arm's linear motion. This dynamic adaptation allows the sealed chamber to maintain its protective function while accommodating the operational movement of the actuator arm, balancing protection with ease of operation through flexible, adaptive sealing.
Data Source
AI summary
A watercraft has a hull, an engine compartment, an engine disposed and a jet pump. A gate is pivotable relative to the jet pump about a gate axis between an up and a down position. A gate actuator assembly includes an actuator housing fixed to the hull, and an actuator arm movable along an actuation axis with respect thereto. The actuator arm is operatively connected to the gate for pivoting the gate about the gate axis. A sealing member encloses a portion of the actuator arm between the actuator housing and the gate. The sealing member extends between a first end fixed with respect to the actuator housing and a second end fixed with respect to the actuator arm, forming a variable volume outer chamber to prevent entry of fluid therein. A passage fluidly communicating with the outer chamber, extends through the hull into the engine compartment.