Retractable Intermediate Axle for Amphibious Vehicle Geometry
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional off-road vehicles face limitations in mobility and on-road performance due to axle placement, which affects breakover, approach, and departure angles, and multiple axle vehicles are cumbersome and inefficient on roads, making them conspicuous and fuel-inefficient.
Innovation Solution
An amphibious vehicle design featuring retractable intermediate axles that support wheels, allowing these axles to be raised above the waterline for water travel and lowered for land travel, enabling improved approach and departure angles off-road while optimizing road performance by allowing tire and suspension tuning for road use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If axles are inset from the outer ends of the vehicle to give an acceptable breakover angle, then breakover angle is improved, but approach angle and departure angle are reduced
Solution Approach 1:
The vehicle is divided into multiple axle segments (front axle, intermediate axle(s), rear axle) that can be independently positioned. The intermediate axle(s) are placed between the front and rear axles, allowing the front and rear axles to be pushed out towards the bumpers to maximize approach and departure angles, while the intermediate axle(s) provide the necessary breakover angle support.
Solution Approach 2:
The intermediate axle(s) are made retractable, allowing dynamic adjustment between protracted and retracted positions. When protracted, they provide additional ground contact for breakover angle; when retracted, they clear the ground to allow maximum approach and departure angles, adapting to different terrain requirements.
2Adaptability or versatility
If multiple axle off-road vehicles are used to improve off-road mobility, then off-road capability is improved, but on-road performance deteriorates due to tyre scrub, noise, fuel consumption, and conspicuousness
Solution Approach 1:
The intermediate axle(s) are designed to be retractable, allowing the vehicle to dynamically reconfigure its wheelbase. On roads, the intermediate axle(s) are retracted to minimize the number of contact patches, reducing tyre scrub, noise, and fuel consumption. Off-road, they are protracted to provide additional support and improve mobility over rough terrain.
Solution Approach 2:
The vehicle changes its effective wheelbase parameter by retracting or protracting the intermediate axle(s). This parameter change allows optimization for different operating conditions: shorter effective wheelbase on roads for better handling and reduced drag, longer effective wheelbase off-road for improved mobility.
3Adaptability or versatility
If intermediate axle is provided for off-road use, then off-road capability is improved, but device complexity increases
Solution Approach 1:
The intermediate axle assembly serves multiple functions: it provides breakover angle support when protracted, clears the ground when retracted, and can be used in different combinations (one or two intermediate axles) depending on the required off-road capability. This multi-functionality justifies the added complexity by delivering multiple benefits from a single structural addition.
Data Source
AI summary
Amphibious vehicle 10 has both land propulsion capability as well as marine propulsion capability. At least two axles with wheels 12 are spaced apart along the length of the vehicle. At least one intermediate axle with retractable wheel(s) 14 is positioned between the other axles. This additional axle may improve manoeuvrability over rough ground. Wheel(s) 14 may be retracted on water and/or on land. Wheels 12may also be retractable. One or more axles may be driven, full time or selectively. The vehicle may plane on water, and may have a vee type hull (11 FIG. 2). Marine propulsion may be by means of a jet drive. Wheel(s) 14 may retract vertically or through arcs around a longitudinal axis of the vehicle. Skid steer may be used. Mudguards, a vehicle roof, and retraction guides for the wheels (slides 16 , FIG. 2) may be fitted. Pairs of slides may provide roof supports. A forward control driving position may be provided.