Electric Drivetrain Transfer Case With PTO for Lockable AWD

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Solution Overview

Problem

Existing electrically operable drive trains for commercial vehicles are inefficient as they require multiple electric motors for propulsion, even when only one is necessary, leading to increased weight, cost, and complexity.

Innovation Solution

A drive train design featuring two transfer cases with electric motors and axles, where one transfer case includes a power take-off, allowing for the transmission of drive power between axles and enabling a lockable all-wheel drive system without the need for additional motors, and allowing independent operation of the power take-off.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple electric motors are used for propulsion in each axle, then reliable all-wheel drive is achieved, but device complexity and cost increase

Engineering Contradiction:
Improveall-wheel drive reliabilityVSAvoidmotor quantity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the propulsion function into a single central electric motor while using mechanical differential locks to distribute power to all wheels. This combines multiple power sources into one, reducing motor quantity while maintaining all-wheel drive capability through mechanical power distribution rather than electrical multiplication

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The central electric motor serves multiple functions: it provides propulsion for all wheels through the drivetrain, and when combined with the differential locks, it enables all-wheel drive operation. This multi-functional approach eliminates the need for separate motors at each axle while maintaining comprehensive drive capability

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

2Power

If multiple electric motors are installed for each axle, then sufficient drive power is provided, but vehicle weight increases

Engineering Contradiction:
Improvedrive powerVSAvoidvehicle weight
Core Design Contradiction:
PowerVSWeight of moving object

Solution Approach 1:

Multiple motor units are merged into a single central electric motor with higher power output. This consolidation reduces the total weight of motor components while maintaining sufficient drive power through optimized powertrain design and mechanical power distribution to all wheels via the drivetrain and differential lock system

Inventive Principle:
Principle #5Merging (Combining)

3Adaptability or versatility

If additional electric motors are added for power take-off functions, then auxiliary power needs are met, but device complexity increases

Engineering Contradiction:
Improvepower take-off capabilityVSAvoidmotor quantity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The central electric motor serves dual purposes: propulsion through the drivetrain and power take-off for auxiliary functions. The power take-off mechanism is integrated into the existing drivetrain architecture, allowing the same motor to perform both primary and secondary functions without requiring additional motor units

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

Solution Approach 2:

The drivetrain and differential lock system act as intermediaries that distribute power from the single central motor to both the wheels for propulsion and to the power take-off mechanism for auxiliary functions. This intermediary power distribution system enables one motor to serve multiple purposes efficiently

Inventive Principle:
Principle #24Intermediary (Mediator)

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 design reduces the need for more powerful and expensive motors by allowing drive power to be transferred between axles, providing efficient and independent operation of the power take-off, and enabling continuous high-performance operation in off-road conditions.

Implementation Method 1

an first electric motor (12) and an second electric motor (15), wherein the first electric motor (12) has a first drive connection to the first transfer case (11) and the second electric motor (15) has a second drive connection to the second transfer case (14)

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Data Source

PatentEP4286201A1Electrically operable drive train and vehicle
Publication Date: 2023.12.06 ZF FRIEDRICHSHAFEN AG
  • EP4286201A1 patent drawingFigure 1
  • EP4286201A1 patent drawingFigure 2
  • EP4286201A1 patent drawingFigure 3

AI summary

The invention relates to an electrically operated drive train (10) comprising a first transfer case (11), a first electric motor (12), and a first axle (13, 13'), as well as a second transfer case (14), a second electric motor (15, 15'), and a second axle (16, 16'), wherein the first transfer case (11) has a first input (17), a first axle output (18), and a first coupling output (19), wherein the second transfer case (14) has a second input (20), a second axle output (21), and a second coupling output (22), and wherein the first coupling output (19) can be coupled to the second coupling output (22) via a coupling shaft (23). The drive train (10) according to the invention is characterized in that the first transfer case (11) further comprises a first power take-off (24). The invention further relates to a corresponding vehicle.