Compact Biwheel Suspension and Torque Control Against Gerbiling

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Solution Overview

Problem

Existing biwheels face issues with cockpit access, gerbiling, suspension, and tire punctures, limiting their practicality for passenger and luggage transport while occupying minimal space and providing weather protection.

Innovation Solution

A biwheel design with suspension assemblies using leaf springs and idler/drive wheels around the rim, electric propulsion, and a central joystick control system to prevent gerbiling and enhance access, combined with solid tires and rear jockey wheels for stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single motor applies torque to the wheel axle, then the wheel structure is simplified, but access to the cockpit becomes difficult and requires impractical gymnastic maneuvers

Engineering Contradiction:
Improvewheel structureVSAvoidcockpit access
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The wheel structure is segmented by removing the traditional hub and spoke configuration, leaving only the rim. This segmentation allows the cockpit access passage to pass through the wheel rim, enabling practical entry and exit without requiring gymnastic maneuvers while maintaining structural simplicity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The access passage is positioned in the third dimension by routing it through the wheel rim structure itself rather than through the ground or side of the vehicle. This dimensional repositioning allows passengers to enter and exit the cockpit at wheel level, eliminating the need for climbing or awkward maneuvers

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Speed

If torque is applied to the wheels to propel the vehicle, then the vehicle can move forward, but the cockpit pitches up and swings back and forth causing gerbiling

Engineering Contradiction:
Improvevehicle propulsionVSAvoidcockpit stability
Core Design Contradiction:
SpeedVSStability of the object's composition

Solution Approach 1:

The counterweight is positioned in the cockpit to balance the rotational torque generated by the drive wheels. When the wheels apply torque to propel the vehicle, the counterweight provides an opposing moment that prevents the cockpit from pitching up and swinging, thereby eliminating gerbiling while maintaining propulsion capability

Inventive Principle:
Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The mass distribution parameters are changed by adding a counterweight to the cockpit. This parameter change modifies the moment of inertia and center of gravity, creating a stabilizing effect that counteracts the oscillatory motion caused by wheel torque during acceleration

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If pneumatic tyres are used to enhance road traction and suspension, then ride comfort is improved, but the tyres are vulnerable to punctures and difficult to mount on large rims

Engineering Contradiction:
Improveride comfortVSAvoidtire puncture resistance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The pneumatic tyre is replaced with a solid tyre that is simpler in construction and does not suffer from punctures. The solid tyre accepts a polymeric insert that can be easily replaced when worn, creating a disposable inner component that maintains reliability while preserving suspension functionality through the leaf spring assembly

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

4Ease of operation

If pneumatic tyres provide suspension to enhance passenger comfort, then ride quality is improved, but mounting and roadside repair present particular difficulties

Engineering Contradiction:
Improvepassenger comfortVSAvoidtire mounting and repair
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

The suspension system is segmented into the solid tyre structure, the polymeric insert, and the leaf spring assembly. This segmentation allows the insert to be independently replaced without affecting the tyre or suspension components, greatly simplifying maintenance and repair operations

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The polymeric insert is designed as a disposable or easily replaceable component that absorbs wear and tear. When the insert becomes worn or damaged, it can be quickly replaced without requiring specialized equipment or skills, eliminating the difficulties associated with pneumatic tyre repair and remounting

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 design allows easy cockpit access, minimizes gerbiling, enhances suspension comfort, and reduces tire maintenance, while maintaining compactness and stability for passenger and luggage transport.

Implementation Method 1

each suspension assembly comprises a spring supporting at least one of an idler wheel or a drive wheel to absorb a shock applied to the main wheel via motion between the main wheel and cockpit

Methodology Applied
Scientific EffectShock absorption: Elasticity

Implementation Method 2

each suspension assembly comprises a spring supporting at least one of an idler wheel or a drive wheel to absorb a shock applied to the main wheel via motion between the main wheel and cockpit

Methodology Applied
Scientific EffectSpring suspension: Spring

Data Source

PatentEP4405239B1A compact ground vehicle with electric propulsion
Publication Date: 2026.03.04 VO VEHICLES LTD
  • EP4405239B1 patent drawingFigure 1~2
  • EP4405239B1 patent drawingFigure 3
  • EP4405239B1 patent drawingFigure 4

AI summary

A biwheel has large left and right main wheels (1, 2) supported by suspension assemblies (7) acting between rims of each main wheel and a payload carrying cockpit (3) suspended above the ground between the wheels. The arrangement facilitates access to the cockpit payload space through the wheels. Each wheel is cambered to deter pitching motion of the cockpit within the wheel. A rear jockey wheel (61) is provided to further deter pitching. Propulsion to the wheels is via electric motors built into drive wheels (16) which are mounted onto a suspension assembly (7). The torque applied to the electric motors can be controlled by a digital control system responsive to sensors such as a cockpit attitude sensor, to further deter pitching motion of the cockpit. Propulsion may additionally be delivered by a manual propulsion system supplemented by the electric motors.