Rotor Nanogenerator Power for Direct Temperature Sensing

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Solution Overview

Problem

Existing electric machines face challenges in supplying sensors associated with the rotor with sufficient electrical energy, leading to limited continuous power due to unknown rotor temperature, which can result in overheating and damage.

Innovation Solution

Integration of a nanogenerator within the rotor to harvest energy from surroundings, such as ambient temperature, vibrations, or fluid flows, to power sensor elements and signal processing units, eliminating the need for batteries or power collection rings and allowing for direct temperature measurement to prevent overheating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If sensors are installed on the rotor to monitor temperature, then measurement precision is improved, but device complexity increases due to the need for additional power supply components

Engineering Contradiction:

Improvetemperature monitoring accuracyVSAvoidpower supply system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The rotor system serves itself by generating electrical energy through its own motion. The nanogenerator converts mechanical energy from rotor rotation into electrical energy, which automatically powers the sensors and signal processing units without requiring external power supply components or batteries.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces complex mechanical power transmission components (such as sliding contacts or batteries) with a nanogenerator that directly converts mechanical motion into electrical energy through the piezoelectric effect, simplifying the overall power supply system.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If power is supplied to rotor sensors via batteries or collection rings, then sensors can operate, but reliability decreases due to limited power capacity and maintenance requirements

Engineering Contradiction:

Improvecontinuous operation reliabilityVSAvoidpower supply capacity

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The rotor system generates its own power continuously through rotation, eliminating the need for finite energy sources like batteries. The nanogenerator converts the mechanical energy of rotor motion into electrical energy, providing unlimited operational capacity as long as the rotor continues to rotate.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent changes the energy supply mode from static (batteries) or limited transmission (collection rings) to dynamic generation, where electrical energy is continuously produced through the piezoelectric effect during rotor rotation, adapting power supply to the operational state.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If safety margin is applied to maximum temperature, then reliability is improved, but productivity decreases due to limited continuous power

Engineering Contradiction:

Improveoverheating protectionVSAvoidcontinuous power output

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent implements a feedback loop where sensors continuously monitor rotor temperature and transmit data to a control device. The control device processes this information and adjusts operating parameters in real-time, enabling optimal operation at or near maximum temperature limits without exceeding safety thresholds.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system performs preliminary temperature monitoring and analysis to predict thermal conditions before critical overheating occurs. By continuously tracking temperature trends and taking preventive action, the system can operate closer to maximum limits while maintaining safety margins.

Inventive Principle:

Principle #10Preliminary action

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 solution enables efficient and accurate temperature monitoring, reduces the risk of overheating, and allows for optimal operation of the electric machine by providing a reliable power supply to sensors and signal processing units, enhancing the machine's performance and installation ease.

Implementation Method 1

The nanogenerator is configured for performing energy harvesting, i.e., harvesting energy from the surroundings. By energy harvesting, it is possible to generate small amounts of electrical energy from surroundings variables, for example, from the ambient temperature, from vibrations, or from fluid flows

Methodology Applied

Scientific EffectEnergy harvesting:

Implementation Method 2

The at least one sensor element can be arranged directly at the rotor and, there, immediately detect condition variables of the rotor, in particular a temperature of the rotor

Methodology Applied

Scientific EffectTemperature detection:

Data Source

PatentUS11916445B2Rotor for an electric machine and electric machine having a rotor with rotor having a cooled nanogenerator used to supply power to sensing device

Publication Date: 2024.02.27 ZF FRIEDRICHSHAFEN AG

AI summary

A rotor (1) for an electric machine (2) includes at least one sensor element (3) configured for detecting condition variables of the rotor (1), a signal processing unit (4) connected to the at least one sensor element (3) and configured for generating measured data from the detected condition variables of the rotor (1) and transmitting the measured data to a control device (5), and a nanogenerator (6) configured for generating electrical energy from at least one surroundings variable and supplying the at least one sensor element (3) and the signal processing unit (4) with electrical energy.