Omnidirectional Front-Wheel Toe-In for Stable Electric Mobility
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Solution Overview
Problem
Existing electromobility vehicles face issues with rider posture stabilization and excessive vibration transmission due to wheel contact with the ground, particularly when rollers come into contact one after another, leading to undesirable tilting and discomfort.
Innovation Solution
The vehicle incorporates omnidirectional front wheels with a toe-in arrangement supported by a suspension system, where the wheels' rotation axes make an angle of 2 to 11 degrees with respect to the horizontal, and a biasing member moves the axle toward the rear side to absorb vibrations, combined with rubber-like material and grooved rollers to mitigate impact forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the front-wheel-side floor frame and the rear-wheel-side floor frame are coupled to each other such that they can tilt in the roll direction with a spring biasing the front-wheel-side floor frame toward the central position, then the wheel assembly can adapt to ground irregularities, but the seat becomes likely to tilt in the roll direction, compromising rider posture stability
Solution Approach 1:
The vehicle body is divided into separate front-wheel-side and rear-wheel-side floor frames that can move independently relative to each other through the swingable coupling, allowing each side to adapt to ground conditions while maintaining overall vehicle stability
Solution Approach 2:
The coupling between floor frames is designed to be dynamic rather than rigid, allowing controlled relative movement and tilting in the roll direction to absorb ground irregularities while the spring provides restoring force to maintain posture stability
2Adaptability or versatility
If rollers are used to form the outer circumferential surface of the wheel, then the wheel can provide good traction and adaptability, but vibrations are generated when the rollers come into contact with the ground one after another, causing rider discomfort
Solution Approach 1:
A rubber buffer member is introduced as an intermediary element between the rollers and the ground contact surface, absorbing and dampening the vibrations generated when rollers contact the ground while maintaining the traction benefits of the roller configuration
Solution Approach 2:
The wheel assembly combines rigid roller elements with flexible rubber buffer material to create a composite structure that provides both the mechanical advantage of rollers for traction and the vibration-damping properties of rubber
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
This configuration stabilizes the rider's posture and reduces vibrations effectively, ensuring a smoother ride by absorbing and damping vibrations through the suspension and toe-in arrangement, without compromising stiffness or tractive force.
Implementation Method 1
the vibrations of the front wheels are transmitted to the vehicle frame in a state where they are reduced by the suspension
Implementation Method 2
the impact force generated when each roller comes into contact with the ground is mitigated
Data Source
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AI summary
This electromobility vehicle includes a vehicle frame (VF), a seat unit mounted to the vehicle frame (VF), a suspension mounted to a front-end side of the vehicle frame (VF), a pair of front wheels (10) aligned in a direction parallel to a width dimension of the vehicle and supported by the suspension, at least one rear wheel (20) supported by the vehicle frame (VF), and a drive device (50) that drives either of the front wheels (10) and the rear wheel (20), where the front wheels (10) are omnidirectional wheels whose outer circumferential surfaces are formed by a plurality of rollers (13, 14) and the pair of front wheels (10) is supported by the suspension (12) such that it is placed in a toe-in arrangement.