Motor Bearing Wear Monitoring with Frequency-Based Offset Correction
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Solution Overview
Problem
Conventional motor bearing wear monitoring devices require manual adjustment of zero settings when the driving frequency changes, leading to erroneous detection and inability to handle flow rate control using inverters without manual operation.
Innovation Solution
A motor bearing wear monitoring device that includes thrust detection coils, a wear amount detection unit, a frequency acquisition unit, and an offset processing unit to automatically adjust signals and maintain detection accuracy by acquiring and processing data corresponding to the driving frequency, allowing for accurate wear measurement without manual intervention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the driving frequency is changed by the inverter to control flow rate, then energy efficiency is improved and valve throttling is eliminated, but the voltage induced in the detection coil varies causing erroneous detection and requiring manual zero adjustment
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the offset value based on the driving frequency. The system stores multiple offset values corresponding to different driving frequencies and selects the appropriate offset based on the current frequency, thereby maintaining accurate wear detection across varying operational conditions without manual intervention
Solution Approach 2:
The patent implements feedback by continuously monitoring the driving frequency and automatically adjusting the offset value accordingly. The microcontroller reads the current driving frequency, retrieves the corresponding offset value from storage, and applies it to the combined signal, creating a closed-loop system that maintains detection accuracy without user intervention
2Measurement precision
If manual zero adjustment is performed every time the driving frequency changes, then detection accuracy is maintained, but operational complexity increases and automatic flow rate control using inverter cannot be implemented
Solution Approach 1:
The patent applies self-service by enabling the monitoring device to automatically adjust its own offset value based on the detected driving frequency. The system autonomously reads the frequency, retrieves the corresponding offset from storage, and applies it without requiring manual user intervention, thereby maintaining both accuracy and ease of operation
Solution Approach 2:
The patent implements dynamics by making the offset value adaptive rather than fixed. The system dynamically adjusts the offset based on real-time driving frequency conditions, allowing the device to automatically adapt to changing operational parameters and maintain accuracy across different operating modes
3Adaptability or versatility
If the voltage induced in the detection coil varies with driving frequency, then the monitoring device can operate at different frequencies, but the corresponding relation between measured value and amount of wear deviates causing erroneous detection
Solution Approach 1:
The patent applies parameter changes by storing multiple offset values in the storage unit, each corresponding to a specific driving frequency. When the driving frequency changes, the system retrieves the appropriate offset value and applies it to the combined signal, thereby maintaining accurate wear measurement across different frequencies without sacrificing adaptability
Solution Approach 2:
The patent introduces an intermediary mechanism - the offset value stored in the storage unit - that mediates between the varying voltage induced in the detection coil and the wear measurement. This intermediary offset compensates for frequency-induced voltage variations, ensuring accurate wear detection regardless of the driving frequency
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 device maintains detection accuracy and enables flow rate control using inverters without manual operation, ensuring reliable monitoring of motor bearing wear even when the driving frequency changes.
Implementation Method 1
detecting a change in magnetic flux corresponding to a mechanical position change of the rotor with respect to a stator of a motor by using a plurality of detection coils attached to the stator
Implementation Method 2
The monitoring device detects a voltage induced in the detection coils by the rotation of the motor
Data Source
AI summary
A motor bearing wear monitoring device (5; 5A; 5B) monitors a wear state of bearings (32, 33) with a plurality of detection coils (C1 to C8). These coils include a plurality of thrust detection coils (C2, C4, C6, C8). The device includes a wear amount detection unit (543) detecting a wear amount of the bearings in a thrust direction, based on a difference between a combined signal of a set of the thrust detection coils (C2, C4) and a combined signal of another set of the thrust detection coils (C6, C8), a frequency acquisition unit (541, 548) acquiring a driving frequency of a motor (3); a data acquisition unit (542, 549) acquiring adjustment data corresponding to the driving frequency; and an offset processing unit (57) executing offset processing to the combined signal so that the difference indicates a wear amount corresponding to the driving frequency, based on the adjustment data.