Heating Device for Motor Vehicle Drive Train and Wheel Bearings

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Motor vehicles experience efficiency losses due to high viscosity of lubricants at low temperatures, leading to reduced energy efficiency during cold starts.

Innovation Solution

A heating device is integrated into the drive train and wheel bearings, powered by recuperation power from a regenerative brake via a DC voltage converter, which reduces lubricant viscosity and improves efficiency by using excess energy that cannot be efficiently stored in the battery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If lubricants are used to reduce friction in drive train components and wheel bearings, then friction is reduced and efficiency is improved, but at low temperatures the lubricant viscosity increases significantly causing efficiency losses

Engineering Contradiction:
Improveenergy efficiencyVSAvoidlow temperature viscosity
Core Design Contradiction:
Loss of energyVSTemperature

Solution Approach 1:

The heating device pre-heats the drive train components and wheel bearings before cold starting the motor vehicle, using recuperation energy from the battery. This preliminary heating action reduces lubricant viscosity in advance, eliminating the efficiency losses that would occur during cold start operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention changes the temperature parameter of the drive train components and wheel bearings by applying heat from the heating device. This parameter change (temperature increase) directly affects the lubricant viscosity, transforming it from a high-viscosity cold state to a low-viscosity warm state, thereby improving efficiency.

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If recuperation power is stored in the battery, then energy is recovered and stored for later use, but the battery has limited charging capacity at low temperatures reducing the amount of power that can be stored

Engineering Contradiction:
Improverecuperation power storageVSAvoidcharging capacity
Core Design Contradiction:
Use of energy by moving objectVSQuantity of substance

Solution Approach 1:

The heating device uses recuperation energy from the battery to heat the drive train components and wheel bearings, creating a self-service system where the recovered energy is immediately reused for a beneficial purpose (heating) rather than being wasted or requiring additional storage capacity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

Instead of discarding the excess recuperation power that cannot be stored in the temperature-limited battery, the system recovers and utilizes this energy by directing it to the heating device, thereby converting what would be wasted energy into useful thermal energy for improving drive train efficiency.

Inventive Principle:
Principle #34Discarding and recovering

3Power

If a heating device is powered directly from the high-voltage recuperation brake, then heating capability is provided, but complex high-voltage protection measures are required increasing device complexity

Engineering Contradiction:
Improveheating powerVSAvoidhigh-voltage protection measures
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

A DC-DC converter is introduced as an intermediary component between the high-voltage recuperation brake and the heating device. This converter steps down the high voltage to a lower voltage level, enabling the heating device to operate with reduced voltage and thereby eliminating the need for complex high-voltage protection measures while still providing sufficient heating power.

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

The solution enhances energy efficiency by reducing friction in drive train components and wheel bearings, particularly during cold starts, while minimizing power loss and eliminating the need for complex high-voltage protection measures.

Implementation Method 1

a heating device (8) designed to heat the drive train component and/or the wheel bearing (12) is provided

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

a DC voltage converter (7) which is connected to the regenerative brake (2) on an input side and to the heating device (8) on an output side and for lowering a voltage level of a recuperation power provided by the recuperation brake (2)

Methodology Applied
Scientific EffectElectrical energy conversion:

Implementation Method 3

using kinetic energy converted into electrical energy when decelerating the motor vehicle by means of the recuperation brake (2)

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3308997B1Motor vehicle and method for operating a motor vehicle
Publication Date: 2021.03.24 AUDI AG
  • EP3308997B1 patent drawingFigure 1
  • EP3308997B1 patent drawingFigure 2

AI summary

Motor vehicle comprising at least one powertrain component (10, 11) and/or at least one wheel bearing (12), wherein a heating device (8) designed for heating the powertrain component (10, 11) and/or the wheel bearing (12), a recuperation brake (2) and a DC voltage converter (7) are provided, which is connected on the input side to the recuperation brake (2) and on the output side to the heating device (8) and is designed to reduce a voltage level of a recuperation power provided by the recuperation brake (2).