Hydrodynamic Converter Pressure Control for Lower Pump Loss

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Solution Overview

Problem

Current hydrodynamic machines face inefficiencies due to constant filling pressure, which varies with speed and torque, leading to high leakage and lower outlet temperatures, as the required filling pressure is set to an unfavorable operating point, resulting in high pump power consumption and unnecessary medium flow.

Innovation Solution

A control valve adjusts inlet pressure based on operating conditions, reducing filling pressure where lower, and increasing it where higher is needed, using a mechanically actuated valve with a prestressing element to optimize flow cross-section and minimize medium flow through the working chamber.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If constant filling pressure is supplied to the hydrodynamic machine, then the working medium pump operates at a fixed pressure point, but this leads to high pump power consumption and high leakage when operating conditions vary

Engineering Contradiction:
Improvestable operationVSAvoidpump power consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by making the filling pressure variable instead of constant. The working medium pump's displacement is adjusted dynamically based on operating conditions (speed and torque), allowing the filling pressure to adapt to varying demands. This resolves the contradiction by enabling stable operation only when needed while reducing energy consumption when full pressure is not required.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of filling pressure from a fixed constant to a variable parameter that adapts to operating conditions. By modifying the pump's displacement parameter in response to speed and torque variations, the system achieves optimal energy efficiency across different operating points while maintaining reliability when required.

Inventive Principle:
Principle #35Parameter changes

2Force

If high filling pressure is maintained, then torque transmission is ensured, but leakage increases and outlet temperatures decrease

Engineering Contradiction:
Improvetorque transmissionVSAvoidworking medium leakage
Core Design Contradiction:
ForceVSLoss of substance

Solution Approach 1:

The patent makes the filling pressure dynamic rather than static. The pressure is adjusted in real-time based on actual operating conditions, providing high pressure only when torque transmission demands it, and reducing pressure when demands are lower. This dynamically adapts the system to minimize leakage while ensuring adequate torque transmission when required.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The filling pressure parameter is changed from a fixed high value to a variable parameter that responds to operating conditions. This parameter change allows the system to maintain sufficient torque transmission capability while reducing unnecessary high pressure that causes leakage and lowers outlet temperatures.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If high filling pressure is applied, then the working medium is forced into the working chamber, but this results in unnecessarily high leakage and lower outlet temperatures

Engineering Contradiction:
Improveworking medium flowVSAvoidleakage loss
Core Design Contradiction:
Quantity of substanceVSLoss of energy

Solution Approach 1:

The patent applies dynamics by adjusting the working medium flow rate dynamically based on operating conditions. The pump's displacement is varied to match the actual demand for working medium in the chamber, preventing excessive flow that would lead to leakage losses and temperature reduction.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The working medium flow parameter is changed from a fixed high rate to a variable rate that adapts to operating conditions. This parameter adjustment ensures sufficient medium supply when needed while minimizing unnecessary flow that causes energy loss through leakage and reduces outlet temperatures.

Inventive Principle:
Principle #35Parameter changes

4Ease of operation

If the working medium pump operates at constant pressure, then the system is simple to control, but pump efficiency decreases across varying operating points

Engineering Contradiction:
Improvecontrol simplicityVSAvoidpump efficiency
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The patent makes the pump operation dynamic by adjusting displacement based on operating conditions. While this adds control complexity, it significantly improves pump efficiency across varying operating points by ensuring the pump operates near its optimal efficiency point regardless of speed or torque demands.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The pump's displacement parameter is changed from a fixed value to a variable parameter that adapts to operating conditions. This parameter change allows the pump to maintain high efficiency across different operating points, overcoming the efficiency degradation that occurs with constant pressure operation.

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 reduces pump power consumption, increases working medium temperatures, and enhances efficiency by matching filling pressure to operational demands, leading to higher outlet temperatures and improved hydrodynamic performance.

Implementation Method 1

a valve body which is subjected to the working medium pressure in the working medium inlet and in the working medium outlet

Methodology Applied
Scientific EffectHydraulic pressure: Pressure Gradient

Implementation Method 2

the valve body splitting the flow through a bypass and carries out the working medium flow flowing through the working medium inlet

Methodology Applied
Scientific EffectElastic force: Spring

Implementation Method 3

the impeller drives the turbine wheel via a hydrodynamic circulatory flow of the working medium in the working chamber

Methodology Applied
Scientific EffectHydrodynamic flow: Convection

Implementation Method 4

at least one centrifugal impeller arranged in the working chamber

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 5

the working medium has the additional task of dissipating the heat generated in the working space from the working space

Methodology Applied
Scientific EffectThermal convection: Convection

Implementation Method 6

a bypass which branches off from the working medium inlet and which opens into a working medium sump

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Data Source

PatentEP3619446B1Hydrodynamic machine, in particular hydrodynamic converter
Publication Date: 2021.03.10 VOITH PATENT GMBH
  • EP3619446B1 patent drawingFigure 1
  • EP3619446B1 patent drawingFigure 2
  • EP3619446B1 patent drawingFigure 3

AI summary

The invention relates to a hydrodynamic machine, in particular a hydrodynamic converter, comprising - a working chamber which can be filled with a working medium and in which at least one bladed pump impeller and a bladed turbine impeller are arranged in order to hydrodynamically transmit a torque and/or drive power from the pump impeller (2) to the turbine impeller (3); - a working medium inlet (4) for supplying the working medium into the working chamber and a working medium outlet (5) for discharging the working medium out of the working chamber; and - a control valve (6) which is provided in the working medium inlet or in a working medium bypass that branches off from the working medium inlet, wherein the control valve can be used to change the working medium quantity flowing into the working chamber by adjusting a flow cross-section for the working medium flowing through the control valve. The hydrodynamic machine according to the invention is characterized in that the control valve is connected to the working medium inlet and/or the working medium outlet and is actuated such that the flow cross-section of the control valve is variably adjusted depending on the working medium pressure in the working medium inlet and depending on the working medium pressure in the working medium outlet.