Shape Memory Coil Resonant Circuit for Motor Thermal Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for protecting electric motors from thermal overload face challenges such as space constraints, high costs, and slow response times, particularly during rapid temperature rises, leading to potential overheating and inadequate shutdown.
Innovation Solution
A device utilizing an electrical oscillating circuit with a coil made of shape memory material, such as nitinol, that changes its oscillation frequency in response to temperature changes, allowing for precise detection and rapid response to temperature increases, connected directly to the EC motor for improved measurement accuracy and response.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional temperature sensors are used to detect motor winding temperature, then temperature monitoring is achieved, but the response time is too slow to prevent rapid temperature increases from causing damage
Solution Approach 1:
The patent replaces traditional temperature sensors with a coil made of shape memory material that directly responds to temperature changes through phase transition. This mechanical/physical substitution eliminates the need for separate sensing elements and signal processing circuits, achieving immediate response to temperature increases and resolving the contradiction between reliability and response time.
Solution Approach 2:
The patent utilizes the phase transition properties of shape memory material in the coil. When the motor winding temperature exceeds a threshold, the shape memory material undergoes phase transition, causing detectable changes in the resonant circuit's oscillation frequency. This phase transition mechanism provides instantaneous detection of temperature increases, solving the slow response time problem of conventional sensors.
2Measurement precision
If additional temperature monitoring assemblies are installed in the motor, then temperature detection capability is improved, but space constraints and installation complexity increase
Solution Approach 1:
The patent integrates the temperature detection function into the existing motor structure by using a coil made of shape memory material that serves both as part of the motor's electromagnetic system and as the temperature sensing element. This multi-functional approach eliminates the need for separate temperature monitoring assemblies, reducing space requirements and installation complexity while maintaining detection precision.
Solution Approach 2:
The patent merges the temperature detection function with the motor's existing coil structure. The coil serves dual purposes: generating the magnetic field necessary for motor operation and detecting temperature changes through shape memory material phase transition. This consolidation eliminates additional assemblies and simplifies installation, resolving the contradiction between measurement precision and device complexity.
3Reliability
If PTC thermistors or other temperature sensor elements are used, then temperature detection is achieved, but the system requires additional costly assemblies and installations
Solution Approach 1:
The patent makes the coil serve multiple functions: it generates the magnetic field for motor operation and simultaneously provides thermal overload protection through shape memory material phase transition. This eliminates the need for separate PTC thermistors or temperature sensor assemblies, reducing manufacturing costs while maintaining reliable thermal protection.
Solution Approach 2:
The patent combines the protective function with the motor's existing coil structure by using shape memory material. This integration eliminates the need for additional sensor elements and their associated mounting hardware, reducing both material costs and assembly complexity while ensuring reliable thermal overload protection.
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 reliable detection of temperature rises and immediate protection against overheating, enhancing operational reliability and safety by providing a fast and accurate means to prevent engine damage.
Implementation Method 1
the coil L of the resonant circuit is made of a shape memory material with at least two different temperature-dependent stable states Z1, Z2 and wherein, when a certain temperature is exceeded or fallen below, the coil L changes from one stable state to the other
Data Source
Figure 1~2
AI summary
The invention relates to an apparatus (1) for detecting a rise in temperature in an EC motor (3) designed with a resonant circuit (10), having at least one coil (L) and a device (20) for measuring the oscillation frequency ω of the resonant circuit (10), the device (1) being designed to be connected to the terminals of the EC motor (3). The coil (L) of the resonant circuit is produced from a shape memory material having at least two different temperature-dependent stable states (Z1, Z2). If the temperature is lower or higher than a certain temperature, the coil (L) changes from one stable state into the other stable state and the oscillation frequency ω of the resonant circuit (10) changes.