Closed Ring Magnet Sensor for Compact Linear Motion Detection

Solution Overview

Problem

Existing sensor arrangements for measuring linear or rotary movements have a large installation space and limited directional freedom due to the arrangement of the magneto-sensitive element between the legs of a U-shaped magnet, restricting miniaturization and movement flexibility.

Innovation Solution

A closed ring magnet design with one pole pointing outward and the other inward, allowing the magneto-sensitive element to be centered, reducing overall height and enabling movement in any plane above or below, thus providing greater freedom in directional movement detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a U-shaped magnet with the magneto-sensitive element arranged between its legs is used, then the sensor arrangement provides robust structure and satisfactory signals, but the overall height becomes large due to the required installation space

Engineering Contradiction:

Improvesignal qualityVSAvoidoverall height

Core Design Contradiction:

ReliabilityVSLength of stationary object

Solution Approach 1:

The patent inverts the conventional U-shaped magnet structure by using a closed ring magnet with opposite pole orientation. Instead of having poles on opposite sides of a gap (U-shape), the closed ring magnet has one pole pointing outward and the other inward, with the magneto-sensitive element positioned in the center. This inversion eliminates the need for the transverse leg structure, significantly reducing the overall height while maintaining the magnetic flux-free area required for proper sensor operation.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The closed ring magnet design allows the magneto-sensitive element to be nested within the central opening of the ring structure. The element is positioned in the magnetic flux-free area at the center of the ring, surrounded by the magnet structure on all sides. This nesting arrangement eliminates the need for additional installation space above and below the components, as their surfaces end together at the top and bottom.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Device complexity

If the magneto-sensitive element is arranged between the legs of a U-shaped magnet, then the structure is simple, but the triggering part can only be moved in a straight line through the legs, limiting directional freedom

Engineering Contradiction:

Improvemagnet structureVSAvoidmovement direction freedom

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent inverts the conventional U-shaped magnet structure by using a closed ring magnet with opposite pole orientation. Instead of having poles on opposite sides of a gap (U-shape), the closed ring magnet has one pole pointing outward and the other inward, with the magneto-sensitive element positioned in the center. This inversion eliminates the need for the transverse leg structure, significantly reducing the overall height while maintaining the magnetic flux-free area required for proper sensor operation.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The closed ring magnet design provides universal adaptability for detecting movements in multiple directions. The trigger part can be moved in any direction in a plane above or below the magneto-sensitive element and magnet, eliminating the restriction to straight-line movement through the legs. This makes the sensor arrangement versatile for various application scenarios including linear and rotary movements.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 closed ring magnet design significantly reduces the overall height of the sensor arrangement, allowing for more flexible directional movement detection and accommodating the sensor in smaller spaces, enhancing its applicability in constrained environments.

Implementation Method 1

a magneto-sensitive element (3), in particular a Hall sensor, being arranged in a magnetic flux-free area (5) of the magnet (2)

Methodology Applied

Scientific EffectHall effect: Hall Effect

Data Source

PatentEP2142889B1Sensor array comprising a closed magnet and a hall sensor in the neutral zone of the magnet

Publication Date: 2015.02.11 HIRSCHMANN AUTOMOTIVE GMBH

AI summary

The invention relates to a sensor array (1) for measuring linear or rotational movements of a part. Said sensor array (1) comprises a magnet (2) and a magneto-sensitive element (3) that is disposed in a magnetic flux-free zone of the magnet (2). According to the invention, the magnet (2) is designed as a closed ring, and one pole of the magnet (2) points outward while the other pole of the magnet (2) points inward. Furthermore, the magneto-sensitive element (3) is arranged in the center of the ring.