Vehicle Drive Train Weight Reduction via Segmented Speed Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional range extender drive trains for motor vehicles are heavy and costly due to the use of multiple gear stages, which increases vehicle weight and reduces efficiency.

Innovation Solution

A drive train design that limits internal combustion engine operation to vehicle speeds above 30 km/h, utilizing a simplified two-gear transmission with positive-locking or power-shift clutches, reducing the need for additional clutches and gear stages, and incorporating a connecting shaft for a compact and lightweight configuration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a conventional motor vehicle transmission with a large number of gear stages is used in the second gear arrangement, then the vehicle can be driven by the internal combustion engine across a wide speed range, but the vehicle weight increases

Engineering Contradiction:
Improvespeed range for internal combustion engine driveVSAvoidvehicle weight
Core Design Contradiction:
Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The speed range for internal combustion engine operation is segmented into two distinct ranges: a first speed range (0-30 km/h) where only electric drive is available, and a second speed range (>30 km/h) where both electric and internal combustion engine drive are available. This segmentation allows the use of a simplified two-gear transmission instead of a complex multi-gear transmission, reducing vehicle weight while maintaining adequate adaptability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the operational parameters by restricting internal combustion engine drive to vehicle speeds above 30 km/h through specifically selected gear ratios. This parameter change (speed threshold) enables the use of a lighter two-gear transmission instead of a heavier conventional multi-gear transmission designed for broader speed range coverage.

Inventive Principle:
Principle #35Parameter changes

2Weight of moving object

If a simplified two-gear transmission is used in the second gear arrangement, then the vehicle weight is reduced, but the adaptability for internal combustion engine drive is limited

Engineering Contradiction:
Improvevehicle weightVSAvoidspeed range for internal combustion engine drive
Core Design Contradiction:
Weight of moving objectVSAdaptability or versatility

Solution Approach 1:

By changing the operational parameter to restrict internal combustion engine drive to speeds above 30 km/h, the invention enables the use of a simplified two-gear transmission. The gear ratios are specifically selected to ensure that the internal combustion engine can only effectively drive the vehicle in this higher speed range, thus achieving weight reduction while maintaining adequate adaptability for the intended use case.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The speed range is segmented such that the lower speed range (0-30 km/h) is reserved for electric drive only, while the higher speed range (>30 km/h) accommodates internal combustion engine drive with a two-gear transmission. This segmentation allows the transmission to be optimized for the specific speed range where the internal combustion engine operates, reducing overall complexity and weight.

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If multiple clutches and gear stages are used to enable internal combustion engine drive at all speeds, then the versatility is improved, but the device complexity and cost increase

Engineering Contradiction:
Improveinternal combustion engine operabilityVSAvoidnumber of clutches and gear stages
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The clutch arrangement is segmented into a first clutch for engaging/disengaging the first gear stage and a second clutch for engaging/disengaging the second gear stage. This segmentation allows each clutch to be optimized for its specific function, reducing overall complexity compared to a single complex clutch system that would be needed to handle all speed ranges and gear stages.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

By changing the operational parameter to restrict internal combustion engine drive to speeds above 30 km/h, the invention eliminates the need for additional clutches and gear stages that would be required to enable ICE operation at lower speeds. This parameter change directly reduces device complexity while maintaining adequate versatility for the intended application.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2714448B1Drive train for a motor vehicle
Publication Date: 2019.06.05 MAGNA PT B V & CO KG
  • EP2714448B1 patent drawingFigure 1~2
  • EP2714448B1 patent drawingFigure 3

AI summary

A drive train (10) for a motor vehicle (11), with a first electric machine (12) for providing driving power, wherein the first electric machine (12) is connected to an electric power accumulator (32); a differential (16) which can distribute driving power to two driven wheels (18L, 18R) or axles of the motor vehicle (11); a first transmission arrangement (14) which connects the first electric machine (12) to the differential (16); an internal combustion engine (20); a second electric machine (24) which is coupled to the internal combustion engine (20) in order to charge the electric power accumulator (32) in a generator mode; and a second transmission arrangement (22) which connects the internal combustion engine (20) to the differential (16); wherein the second transmission arrangement (22) has a first gear stage (G1) and a second gear stage (G2) which are alternatively switchable by means of a clutch arrangement (60) for transmitting driving power from the internal combustion engine (20) to the differential (16).