Screw Pump Coolant Circuit for Motor Vehicle Drive

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Solution Overview

Problem

Existing drive devices for motor vehicles lack the ability to quickly adapt to changing operating points while maintaining high efficiency and good acoustic behavior, particularly in terms of temperature control through coolant circuits.

Innovation Solution

The use of a screw pump as the coolant pump, which operates on the positive displacement principle, allowing for rapid adjustment to changing operating conditions and offering higher efficiency and better acoustic performance compared to traditional pumps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a traditional centrifugal pump is used in the coolant circuit, then the pump can handle high volume flows and low back pressures, but the coolant circuit cannot be adjusted quickly to changing operating points and has lower efficiency

Engineering Contradiction:
Improvecoolant volume flowVSAvoidadjustability to operating points
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent applies parameter changes by switching from a centrifugal pump design to a screw pump design, which fundamentally changes the pump's operating characteristics. The screw pump's positive displacement mechanism allows for rapid adjustment of coolant volume flow in response to changing operating points, while maintaining high efficiency through its ability to deliver consistent flow rates independent of pressure variations.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If a traditional centrifugal pump is used in the coolant circuit, then the pump structure is simpler, but the efficiency and acoustic behavior are inferior

Engineering Contradiction:
Improvepump structureVSAvoidpump efficiency
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The patent replaces the centrifugal force-based mechanical system with a positive displacement screw pump mechanism. This substitution fundamentally changes how mechanical energy is transferred to the coolant, resulting in higher efficiency by reducing energy losses associated with turbulence and vortex formation in centrifugal pumps. The screw pump's gradual compression and displacement of coolant creates smoother flow patterns and reduces acoustic emissions.

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

3Power

If the coolant pump speed is increased to improve cooling capacity, then the cooling capacity increases, but the energy consumption and noise increase

Engineering Contradiction:
Improvecooling capacityVSAvoidpump energy consumption
Core Design Contradiction:
PowerVSUse of energy by moving object

Solution Approach 1:

The screw pump design enables more efficient conversion of rotational speed to coolant volume flow compared to centrifugal pumps. The positive displacement mechanism ensures that each rotation delivers a consistent volume of coolant, allowing for better control of cooling capacity relative to energy input. This results in improved power efficiency where increased cooling capacity can be achieved with proportionally less energy consumption and reduced noise levels.

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

The screw pump design enables dynamic temperature control with increased efficiency and reduced noise, overcoming limitations of traditional pumps in high volume flows and low back pressures, while providing reversible flow direction and energy savings through low outlet pressure.

Implementation Method 1

The coolant pump (5) is designed as a screw pump. Such a screw pump works according to the positive displacement principle or is present as a positive displacement pump.

Methodology Applied
Scientific EffectPositive displacement principle: Pump

Implementation Method 2

The heat is removed and/or supplied with the aid of the coolant circuit or by means of the coolant present in the coolant circuit

Methodology Applied
Scientific EffectHeat dissipation: Heat Sink

Implementation Method 3

The cooling capacity of the coolant circuit is brought about by adjusting the coolant pump, for example by adjusting the speed of the coolant pump. The higher the speed of the coolant pump, the greater the coolant volume flow that is circulated in the coolant circuit.

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3899281B1Drive device for a motor vehicle
Publication Date: 2023.03.08 AUDI AG
  • EP3899281B1 patent drawingFigure 1

AI summary

The invention relates to a drive device (1) for a motor vehicle, comprising at least one drive unit (2) and a coolant circuit (3) for the temperature control of the at least one drive unit (2), wherein at least one coolant pump (5) is arranged in the coolant circuit (3) for circulating a water-containing coolant in the coolant circuit (3). According to the invention, it is provided that the coolant pump (5) is designed as a screw pump.