Self-Energizing Magnetic Sensor for Linear Motion
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Solution Overview
Problem
Existing sensing technologies for detecting movement of ferrous elements in linear and rotational motion devices do not allow for real-time detection of deterioration, leading to potential loss of useful life and undetected failures until they occur.
Innovation Solution
A self-energizing, non-contacting sensing device using a permanent magnet, ferrous conductors, and an inductor coil with a microprocessor to detect the presence or absence of moving ferrous elements by varying electromotive force, eliminating the need for an external power source and enhancing the detection of movement without interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If routine maintenance schedules are adopted for periodic inspections, then assemblies can be used to their full useful life, but real-time detection of deterioration is not possible and useful life may be lost due to premature replacement or undetected failures
Solution Approach 1:
The patent replaces mechanical contact-based sensing with a magnetic field-based sensing system. A permanent magnet generates a magnetic field that interacts with ferrous rolling elements without physical contact. When a rolling element enters the magnetic field, it distorts the field and induces a signal in a pickup coil, enabling real-time detection of element presence and motion without mechanical interference.
Solution Approach 2:
The patent introduces a magnetic field as an intermediary between the sensing system and the rolling elements. The permanent magnet creates the magnetic field, and the ferrous rolling elements act as intermediaries that carry magnetic flux between the magnet poles. This indirect sensing method allows detection without direct contact, enabling real-time monitoring while preserving the full useful life of the assemblies.
2Measurement precision
If non-contacting sensing is used to detect ferrous elements, then detection accuracy is improved, but device complexity increases due to additional components
Solution Approach 1:
The patent applies local quality by concentrating the sensing function in a localized magnetic field region between the permanent magnet poles. The ferrous conductors are positioned specifically to carry magnetic flux only where needed, and the pickup coil is placed precisely where the magnetic field distortion occurs. This localized approach achieves high detection accuracy without requiring complex system-wide modifications.
Solution Approach 2:
The patent utilizes parameter changes in the magnetic field as rolling elements pass through the sensing zone. The presence, position, and motion of ferrous elements cause measurable changes in magnetic flux density and induced voltage in the pickup coil. By monitoring these parameter changes, the system achieves precise detection with a relatively simple device structure.
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
Enables real-time monitoring of ferrous elements, reducing component costs, increasing manufacturing efficiency, and extending the useful life of motion assemblies by detecting issues before they lead to failure.
Implementation Method 1
a permanent magnet with a pair of ferrous conductors... One of the ferrous conductors has an end attached to the permanent magnet to carry magnetic flux density from the magnet
Implementation Method 2
The inductor coil is wound about one of the ferrous conductors with the inductor coil being arranged in communication with the microprocessor... the electromotive force imparted on the inductor coil is substantially increased
Implementation Method 3
The free ends of the ferrous conductors are spaced from one another to provide a gap. The gap provides a substantial reluctance in the absence of the moving ferrous elements to diminish the electromotive force imparted on the inductor coil
Data Source
AI summary
A self-energizing, non-contacting sensing device for detecting movement of ferrous elements, methods of use and assemblies therewith. The device includes a permanent magnet, a pair of ferrous conductors, an inductor coil and a microprocessor. The ferrous conductors are attached to the permanent magnet with free ends of the ferrous conductors being spaced from one another to provide a gap. The gap provides an open circuit in the absence of the moving ferrous elements and a substantially closed circuit in the presence of the moving ferrous elements. When the circuit alters between open and closed states, in the absence and presence of the moving ferrous elements, respectively, an electromotive force imparted on the inductor coil generates an alternating current. The microprocessor is configured to detect the alternating current produced in the inductor coil, and thus, can assess whether the ferrous elements are moving in a normal or abnormal manner.