Portable Class-II Lubrication with Isolated Low-Voltage Motor Drive
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Solution Overview
Problem
Existing lubrication devices for wind-turbines and other systems without a common earth connection are unsafe due to the requirement of a protective earth connection, as they typically use class-I appliances with frequency converters that need grounding, making them unsuitable for environments without a common earth potential.
Innovation Solution
A class-II lubrication device design that substitutes frequency converters with a class-II power supply and motor controller, ensuring sufficient isolation and operating voltages below 50 Volts AC or 120 Volts DC, eliminating the need for an earth connection and providing safe operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If class-I appliances with frequency converters are used in lubrication devices, then effective lubrication functionality is achieved, but the device requires a protective earth connection which is unsafe for environments without a common earth potential
Solution Approach 1:
The invention extracts and eliminates the frequency converter component that requires earth grounding, replacing it with a class-II power supply and motor controller combination that operates without needing a protective earth connection, thereby enabling safe operation in environments without common earth potential
Solution Approach 2:
The invention changes the electrical parameters by operating the motor at voltages below 50 Volts AC or 120 Volts DC through a class-II power supply, which fundamentally alters the safety requirements and eliminates the need for protective earth connections while maintaining effective motor operation
2Ease of operation
If frequency converters are used to control the motor, then precise motor control is achieved, but the device becomes class-I and requires grounding
Solution Approach 1:
The invention substitutes the frequency converter (electromechanical system requiring grounding) with a class-II power supply and electronic motor controller system that provides comparable motor control precision without the grounding requirement, replacing a grounded system with an isolated double-insulated system
Solution Approach 2:
The class-II power supply acts as an intermediary between the mains power and the motor controller, providing galvanic isolation and double insulation that enables safe operation without earth connection while still delivering precise motor control through the motor controller
Data Source
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AI summary
The present disclosure relates to a portable Extra-Low Voltage (ELV) class-II lubrication device comprising: at least one class-11 power supply; at least one electric motor controller powered by the at least one power supply; at least one electric motor controlled by the at least one motor controller; at least one pump activated by the at least one electric motor and connected to at least one lubricant container, the pump configured to pump a lubricant from the at least one container to at least one target to be lubricated, wherein an output voltage of the at least one power supply and an output voltage of the at least one motor controller and an operating voltage of the at least one motor is equal to or less than 50 Volts AC or 120 Volts DC.