Hydrodynamic Retarder Temperature Control for Braking Torque Stability

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Solution Overview

Problem

Current hydrodynamic retarder control systems often reduce braking power unnecessarily due to high temperatures, leading to braking torque fluctuations and overheating, especially during non-braking and repeated braking operations.

Innovation Solution

A method for controlling a hydrodynamic braking device that uses a temperature sensor to measure the temperature within the working space, allowing for adaptive braking power adjustment and smooth transitions between control temperatures to optimize braking performance and prevent overheating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the measured temperature in the working medium circuit is used to control the retarder, then the braking power is reduced when temperature exceeds limits, but this leads to unnecessary braking power reduction and torque fluctuations when the cooling system is actually capable of dissipating heat

Engineering Contradiction:
Improvebraking power availabilityVSAvoidbraking torque jumps and fluctuations
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality by implementing different control strategies for different operating conditions. During non-braking operation, the control temperature is assumed to be lower than measured to prevent unnecessary braking power reduction. During braking operation, the actual measured temperature is used for accurate thermal management. This localized adaptation of control parameters to specific operational contexts resolves the contradiction between reliability and harmful fluctuations.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements dynamics by making the control temperature adaptive rather than static. The control system dynamically adjusts the control temperature based on whether the retarder is in braking or non-braking operation. This dynamic adaptation allows the system to respond appropriately to actual thermal conditions while avoiding unnecessary braking power reductions, thereby eliminating torque fluctuations and improving braking power availability.

Inventive Principle:
Principle #15Dynamics

2Productivity

If the measured temperature is used for control during non-braking operation, then braking power is reduced unnecessarily, but if temperature is not monitored, overheating may occur during braking

Engineering Contradiction:
Improvebraking power availabilityVSAvoidworking medium temperature
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The patent applies preliminary action by assuming a lower control temperature during non-braking operation before actual braking begins. This preliminary assumption prevents unnecessary braking power reduction and maintains productivity. The system prepares for potential braking by having temperature monitoring ready, but does not prematurely restrict braking power based on temperatures measured during non-braking conditions, thus avoiding unnecessary productivity loss while maintaining safety.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If the retarder is controlled based on high measured temperatures, then overheating is prevented, but braking power is reduced unnecessarily leading to loss of braking availability

Engineering Contradiction:
Improvethermal managementVSAvoidbraking power
Core Design Contradiction:
ReliabilityVSPower

Solution Approach 1:

The patent applies parameter changes by modifying the control temperature parameter based on operational state. During non-braking operation, the control temperature is set lower than the measured temperature to maintain braking power availability. During braking operation, the actual measured temperature is used for accurate thermal management. This parameter adaptation resolves the contradiction between reliable thermal management and maintaining adequate braking power.

Inventive Principle:
Principle #35Parameter changes

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 ensures improved braking behavior and power availability by promptly adjusting braking power based on real-time temperature measurements, reducing sudden torque changes and overheating risks, while maintaining maximum braking power when feasible.

Implementation Method 1

a control temperature T circuit is temporarily used to control the hydrodynamic retarder, at least during braking operation, which comes from a temperature sensor that is positioned in such a way that it can be used to determine a temperature T circuit in the working space of the retarder can be measured

Methodology Applied
Scientific EffectTemperature measurement:

Implementation Method 2

The resulting heat must be dissipated, which is done by at least a portion of the working medium circulating in a circuit that is connected to or incorporated into a cooling circuit, via which the excess heat can be dissipated

Methodology Applied
Scientific EffectHeat dissipation: Cooling

Implementation Method 3

In braking operation, the working space is at least partially filled and a circulatory flow is formed in the working space, via which a torque, known as the braking torque of the retarder, can be transmitted from the stator to the rotor

Methodology Applied
Scientific EffectHydrodynamic torque transmission:

Data Source

PatentEP3247599B1Brake device with retarder, and method for regulating such a brake device
Publication Date: 2021.08.11 VOITH PATENT GMBH
  • EP3247599B1 patent drawingFigure 1
  • EP3247599B1 patent drawingFigure 2~3
  • EP3247599B1 patent drawingFigure 4

AI summary

The invention relates to a brake device with a hydrodynamic retarder, comprising at least one rotor blade wheel and one stator blade wheel (2, 3) which are arranged in a common housing and which together form a toroidal working chamber (4) that can be filled with a working medium for the braking operation of the retarder and emptied again for the non-braking operation of the retarder. The hydrodynamic retarder also comprises an external cooling circuit line (15) which runs from the working chamber (4) to a cooler (19) and back. In order to achieve an improved braking power, a temperature measurement Tcircuit is temporarily used which is carried out by a temperature sensor that is positioned such that a temperature can be measured in the working chamber (5) using the temperature sensor in order to regulate the hydrodynamic retarder at least during the braking operation.