Power-Split Range Transmission for Shift Energy Recuperation

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Solution Overview

Problem

Existing group transmission devices face inefficiencies in energy usage and require interruptions in tractive force during shifting, often converting shifting energy into heat and necessitating synchronization with internal combustion engines, while also requiring double clutches and multi-plate clutches.

Innovation Solution

A power-split transmission device with a planetary gear set, torque adjustment device, and switching units that allow for shifting without torque interruption, enabling energy recuperation and gear changes without power flow interruption by temporarily storing shifting energy using an electric machine or energy storage system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If dual-clutch transmission is used for shifting, then gear changes can be performed, but shifting energy is converted into heat and requires synchronization with internal combustion engine

Engineering Contradiction:
Improveshifting speedVSAvoidshifting energy loss
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The patent converts the harmful effect of shifting energy into beneficial regenerative energy. The torque-adjusting device (electric motor) captures the kinetic energy that would otherwise be lost as heat during shifting, stores it temporarily, and feeds it back into the drive system after the shift is complete. This transforms energy waste into a useful resource that can improve overall system efficiency.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Adaptability or versatility

If conventional switching units are used for coupling shafts, then gear changes are possible, but torque interruption occurs during shifting

Engineering Contradiction:
Improvegear selection flexibilityVSAvoidcontinuous power transmission
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The torque-adjusting device serves as an intermediary between the input shaft and countershaft during shifting operations. Instead of directly coupling these shafts with conventional switching units that interrupt torque flow, the torque-adjusting device mediates the connection, allowing smooth torque transfer while enabling gear changes. This intermediary component prevents torque interruption while maintaining gear selection flexibility.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If multi-plate clutches and brakes are used for torque adjustment, then gear changes can be achieved, but device complexity increases

Engineering Contradiction:
Improvegear shifting capabilityVSAvoidtransmission structure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical torque adjustment mechanisms (multi-plate clutches and brakes) with an electric motor-based torque-adjusting device. This substitution eliminates the need for multiple friction-based components while achieving the same torque control function. The electric motor provides precise torque adjustment with fewer moving parts, thereby reducing device complexity while maintaining gear shifting capability.

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

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 configuration enhances energy efficiency, allows for wear-free starting, reduces shifting times, eliminates the need for double clutches, and enables free gear selection with no torque interruption during shifting, facilitating smooth and efficient gear changes.

Implementation Method 1

the torque-adjusting device, especially by an electric motor

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 2

it is particularly possible to temporarily store the shifting energy in conjunction with the torque-adjusting device, especially in the form of an electric motor and/or an energy storage system

Methodology Applied
Scientific EffectRegenerative braking: Electromagnetic Induction

Implementation Method 3

temporarily store the shifting energy in conjunction with the torque-adjusting device, especially in the form of an electric motor and/or an energy storage system

Methodology Applied
Scientific EffectEnergy storage: Battery (electricity)

Data Source

PatentEP3669100B1Range-change transmission device
Publication Date: 2021.03.17 MERCEDES BENZ GROUP AG
  • EP3669100B1 patent drawingFigure 1
  • EP3669100B1 patent drawingFigure 2
  • EP3669100B1 patent drawingFigure 3

AI summary

The invention relates to a range-change transmission device, in particular a splitter transmission, with an input shaft (11), with an output shaft (12), with a countershaft (13), with at least one planetary gear set (P1) and with a torque adaptation device (14), wherein a first transmission element (P11) of the planetary gear set (P1) is permanently coupled fixedly to the output shaft (12) so as to rotate with it, wherein a second transmission element (P12) of the planetary gear set (P1) is coupled or can be coupled directly to the countershaft (13), wherein a third transmission element (P13) of the planetary gear set (P1) is permanently coupled fixedly to the input shaft (11) so as to rotate with it, and wherein the countershaft (13) is coupled or can be coupled to the torque adaptation device (14), wherein the range-change transmission device has a first shifting unit (S1) which is provided to couple the countershaft (13) to the output shaft (12).