Hydrodynamic Retarder Integration via Power Take-Off Shaft

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Solution Overview

Problem

Existing drive train systems with hydrodynamic retarders face challenges in cost-effective integration and retrofitting, requiring minimal redesign and optimal use of installation space, while maintaining robustness and minimizing fault susceptibility.

Innovation Solution

A drive train design incorporating a single-stage, unregulated hydrodynamic retarder positioned on the transmission side, connected to the power take-off shaft, with a simple on/off switching mechanism and integration into the vehicle cooling circuit, allowing for efficient power transmission and cooling without temperature regulation, utilizing a synchronizing clutch for switching and a filling device for medium management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a hydrodynamic retarder is integrated into an existing drive train, then the braking function is added, but the integration cost and complexity increase due to redesign requirements

Engineering Contradiction:
Improvebraking functionVSAvoidintegration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The power take-off shaft is designed to serve dual functions: both driving auxiliary units (traditionally) and driving the hydrodynamic retarder. This multi-functionality allows the retarder to be integrated without requiring dedicated new drive shafts or complex mounting arrangements, thereby adding the braking function while minimizing integration complexity and cost.

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

2Productivity

If a regulated retarder with temperature control is used, then the braking torque can be optimized, but the device complexity and cost increase

Engineering Contradiction:
Improvebraking torque optimizationVSAvoidtemperature regulation system
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent employs a single-stage, unregulated retarder design that foregoes expensive temperature regulation systems. While regulated retarders with temperature control can optimize braking torque, this invention accepts a simpler, unregulated approach that reduces device complexity and cost, particularly suitable for applications where extreme precision is not required.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

Instead of implementing full temperature regulation with multiple control stages, the patent uses a single-stage unregulated design that provides sufficient braking performance for the intended application without the complexity of temperature control systems. This partial action approach achieves adequate braking torque optimization without excessive complexity.

Inventive Principle:
Principle #16Partial or excessive action

3Manufacturing precision

If a synchronizing clutch is used for switching the retarder, then the switching precision is improved, but the device complexity increases

Engineering Contradiction:
Improveswitching precisionVSAvoidclutch mechanism
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

A synchronizing clutch is introduced as an intermediary switching mechanism between the power take-off shaft and the retarder. This clutch provides precise engagement and disengagement of the retarder, ensuring smooth switching without direct mechanical冲击. The clutch acts as a mediator that protects the drivetrain from shock loads while maintaining switching precision.

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 approach enables a cost-effective, robust, and fault-resistant integration of the hydrodynamic retarder, minimizing redesign needs and optimizing space, with efficient power transmission and cooling, and allows for straightforward on/off operation without complex torque regulation.

Implementation Method 1

a circulatory flow of a working medium occurs during braking operation in order to hydrodynamically transmit torque from the primary wheel to the secondary wheel and thereby brake the primary wheel

Methodology Applied
Scientific EffectHydrodynamic torque transmission: Hydraulic Press

Implementation Method 2

the hydrodynamic retarder is designed to be cooled, in particular by means of the vehicle cooling circuit

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP2640618B1Drive train with hydrodynamic retarder and brake torque setting method
Publication Date: 2015.05.27 VOITH PATENT GMBH
  • EP2640618B1 patent drawingFigure 1

AI summary

The invention relates to a drive train, in particular of a motor vehicle having a drive engine, comprising a main output shaft by means of which drive wheels or another assembly can be driven; having a hydrodynamic retarder comprising a driven bladed primary wheel and a bladed secondary wheel which is fixed or driven in the opposite direction to the primary wheel, said wheels forming with one another a toroidal working space which is filled or can be filled with a working medium, in order to transmit torque hydrodynamically from the primary wheel to the secondary wheel; the drive engine has a secondary output shaft by means of which the primary wheel of the retarder is driven. The invention is characterized in that the hydrodynamic retarder is embodied as a single-stage, uncontrolled retarder which can be switched exclusively between a switched-on state and a switched-off state.