Non-Coaxial Electrical Axle Torque Vectoring

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Solution Overview

Problem

Current 12V electrical power systems in passenger cars result in high currents and losses, necessitating larger cables and inefficient high-power electronics, which can be mitigated by transitioning to a 48V system for hybrid drive applications.

Innovation Solution

An electrical axle designed for medium to high voltage (48V) operation, incorporating a torque vectoring device with a non-coaxial electrical motor, reduction gear, and gear shift mechanism to achieve efficient torque distribution and reduced motor torque requirements, allowing for hybrid drive configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a 12V electrical power system is used in passenger cars, then the system is simple and compatible with existing infrastructure, but high currents result in high losses and increased cable dimensions

Engineering Contradiction:
Improveelectrical lossesVSAvoidpower system complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent changes the voltage parameter from 12V to 48V in the electrical power system. This parameter change reduces electrical losses and allows for smaller cable dimensions while maintaining system functionality. The 48V system enables more efficient power transmission for hybrid drive applications without requiring completely new system architecture.

Inventive Principle:
Principle #35Parameter changes

2Power

If high power electronics are used to compensate for 12V system limitations, then sufficient power can be delivered, but cable dimensions and system complexity increase

Engineering Contradiction:
Improveelectrical powerVSAvoidcable dimensions
Core Design Contradiction:
PowerVSLength of stationary object

Solution Approach 1:

By increasing the voltage parameter to 48V, the patent enables higher power transmission through the same or smaller cable cross-sections. This eliminates the need for oversized cables that would be required in a 12V system to deliver the same power levels.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If a coaxial electrical motor design is used, then the structure is simple, but torque vectoring capability is limited

Engineering Contradiction:
Improvemotor structureVSAvoidtorque vectoring capability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent employs a non-coaxial motor design where the motor shaft is offset from the axle centerline. This asymmetric configuration enables torque vectoring capability by allowing differential torque application to left and right wheels, improving vehicle handling and stability without requiring completely complex multi-motor architectures.

Inventive Principle:
Principle #4Asymmetry

4Device complexity

If direct electrical motor to wheel connection is used, then the system is simple, but torque control and speed range are limited

Engineering Contradiction:
Improvetransmission systemVSAvoidtorque control capability
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent merges the electrical motor with a reduction gear mechanism in a single integrated unit. This combination provides both speed reduction and torque multiplication while maintaining a relatively simple overall structure. The reduction gear enables the motor to operate at optimal speeds while delivering high torque to the wheels across a wider speed range.

Inventive Principle:
Principle #5Merging (Combining)

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

Enables a more efficient and cost-effective hybrid drive system with reduced component complexity, enabling peak wheel torque of 1600-2000 Nm in low range speed while maintaining sufficient traction at low speeds, and minimizing losses in neutral mode.

Implementation Method 1

an electrical motor (40) arranged non-coaxial with respect to the two drive shafts (22, 24)

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3277530B1An electrical axle
Publication Date: 2020.12.02 BORGWARNER SWEDEN AB
  • EP3277530B1 patent drawingFigure 1~2

AI summary

An electrical axle is provided. The electrical axle comprises an electrical motor (40) which is selectively connected to a differential (30) via a reduction gear (50) and a planetary gear set (60), said planetary gear set (60) having one input (66) and two outputs (64, 66), The electrical axle (20) further comprises a gear shift mechanism (70) configured to selectively connect a differential housing (32) to one of said outputs (66, 64).