Regenerative Differential for Vehicle Steering Control

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Solution Overview

Problem

Existing differential systems for vehicles, both differentially steered and front-wheel steered, face inefficiencies and imprecisions due to reliance on friction for steering control, leading to issues with wheel slip and reduced drivetrain efficiency, especially in uneven traction conditions.

Innovation Solution

A gearing assembly with a differential configured to engage axle shafts and driven by a variable speed reversible motor, allowing for precise control of differential rotation rates without relying on friction, using adjustment gears and a differential control pinion gear to alter the rotation rates of axle shafts proportionally.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If friction-based braking is used to control differential rotation rates, then steering control can be achieved, but drivetrain efficiency is reduced due to frictional losses

Engineering Contradiction:
Improvesteering controlVSAvoiddrivetrain efficiency
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The patent replaces friction-based braking mechanisms with a regenerative differential system that uses a control motor and gear mechanism to actively control the rotation rates of drive wheels. The control motor (24) connects to a control shaft (25) with a control pinion gear (33) that meshes with planet gears (61a, 62a, 63a, 64a, 65a, 66a), providing precise mechanical control without frictional energy loss.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If friction-based braking is used to control differential rotation rates, then steering control can be achieved, but steering precision is reduced

Engineering Contradiction:
Improvesteering controlVSAvoidrotation rate precision
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent replaces imprecise friction-based braking with a controlled mechanical system where the control motor (24) provides precise rotational control through the control shaft (25) and pinion gear (33). This mechanical linkage directly controls the planet gears (61a-66a) to achieve exact differential rotation rates without the variability inherent in friction-based systems.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If multiple control shafts and intermeshing gears are added to achieve regenerative differential control, then steering precision is improved, but device complexity increases

Engineering Contradiction:
Improverotation rate precisionVSAvoiddifferential structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent integrates multiple functions into a unified differential system. The control motor (24) and control shaft (25) with pinion gear (33) serve both to control differential rotation for steering and to maintain precise rotation rate control during operation. The planet gears (61a-66a) simultaneously transmit power and enable controlled differential motion, reducing the need for separate control mechanisms.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Loss of energy

If regenerative differential control is implemented, then drivetrain efficiency is improved, but device complexity increases

Engineering Contradiction:
Improvedrivetrain efficiencyVSAvoiddifferential structure
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent creates a multi-functional differential system where the control motor (24), control shaft (25), and pinion gear (33) integration provides both steering control and rotation rate management in a single unified mechanism. This eliminates the need for separate friction-based braking systems or additional control shafts, achieving regenerative efficiency without proportionally increasing complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3433122B1Regenerative differential for differentially steered and front-wheel steered vehicles
Publication Date: 2021.09.01 CHU SHAUN
  • EP3433122B1 patent drawingFigure 1
  • EP3433122B1 patent drawingFigure 2
  • EP3433122B1 patent drawingFigure 3

AI summary

Disclosed herein are systems, gearing assemblies and methods for controlling a differential rotation rate between shafts of a vehicle using a variable speed reversible motor. An embodiment includes a gearing assembly including a differential configured to engage a first axle shaft, a second axle shaft, and a drive shaft of a vehicle. The gearing assembly further includes a first plurality of alignment gears and a second plurality of adjustment gears configured to engage the differential, configured to be driven by a variable speed reversible motor of the vehicle, and configured to controllably alter a rotation rate of a first axle shaft relative to a rotation rate of the second axle shaft based on rotation produced by the variable speed reversible motor.