Fan Motor Restart Control for Bearing Deterioration Detection
Solution Overview
Problem
Existing electronic apparatuses with fan motors fail to detect fan motor deterioration before start failure, leading to potential operational hindrances and increased mechanical rotational load due to bearing wear and contamination, which can result in premature failure.
Innovation Solution
An electronic apparatus with a fan motor that includes a rotation state detection unit, a display unit, and a restart control unit to detect and display fan motor deterioration, allowing for proactive replacement and continued operation until the motor's natural life expectancy is reached, using methods such as forward and backward rotations or torque increase to restart the motor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the fan motor is operated continuously to cool the numerical controller, then the cooling function is maintained, but the mechanical rotational load increases due to bearing wear and contamination, leading to premature failure
Solution Approach 1:
The system performs preliminary detection of fan motor deterioration by monitoring rotation characteristics during operation. Before the bearing completely fails, the detection unit identifies changes in rotation speed, vibration, or current consumption patterns, allowing preventive maintenance to be scheduled and avoiding sudden motor failure that would disrupt cooling operation.
Solution Approach 2:
The system continuously monitors fan motor operation parameters and provides feedback to the control unit. When deterioration is detected through changes in rotation characteristics or increased mechanical load, the system can alert operators to replace the motor before complete failure occurs, balancing continuous cooling operation with preventive maintenance scheduling.
2Measurement precision
If the fan motor operation is monitored using prior art methods (thermal time constant, fan speed comparison), then some deterioration can be detected, but start failure due to bearing wear and contamination cannot be predicted in advance
Solution Approach 1:
The invention replaces mechanical detection methods with electrical sensing. Instead of physically inspecting bearing condition or manually testing motor startup, the system uses electrical sensors to monitor rotation characteristics, current consumption, and vibration patterns. This electrical monitoring system can detect early signs of bearing deterioration that precede complete start failure, enabling predictive maintenance.
Solution Approach 2:
The system introduces an intermediary detection unit that monitors the fan motor's electrical and mechanical characteristics during operation. This intermediary device detects changes in rotation speed, current draw, or vibration that indicate bearing wear or contamination buildup, serving as an early warning system before the motor completely fails to start.
3Ease of operation
If the fan motor is restarted after stop periods, then operational flexibility is improved, but the coefficient of friction increases and mechanical rotational load becomes higher, causing start failure before deterioration is detected
Solution Approach 1:
Before each restart operation, the system performs a preliminary electrical monitoring check during the startup phase. By detecting changes in inrush current, startup time, or initial rotation characteristics, the system can identify bearing deterioration that makes restarting difficult, even if the motor was previously operating normally. This allows operators to anticipate restart failures due to increased friction from bearing wear.
Data Source
AI summary
If a fan motor in a stopped state remains stopped even when it is powered on, restart processing of the fan motor is carried out by rotating the fan motor forward and backward. If the fan motor rotates as a result of the restart processing, an indication to prompt replacement of it is displayed. If the fan motor remains stopped without rotating, in contrast, it is determined to be defective, and an electronic apparatus is stopped.