Sensor Support Member for Consistent Air Gap in Rotation Detection

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Solution Overview

Problem

Existing rotation detection systems in bearings face inaccuracies due to varying air gap thickness between sensors and encoder washers, especially when sensors are eccentrically positioned or the rotation axis experiences transverse movements, leading to perturbations in rotation detection.

Innovation Solution

A rotation detection set with a support member that accurately positions sensors within a housing, ensuring they are grouped in an angular sector where air gap thickness remains constant, using a holder to mount sensors on a printed circuit board and integrating them into a compact support member that maintains sensor alignment with the encoder washer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If sensors are distributed around the encoder washer to detect rotation parameters, then detection coverage is improved, but air gap thickness varies due to sensor excentration leading to detection inaccuracies

Engineering Contradiction:

Improverotation detection accuracyVSAvoidsensor positioning consistency

Core Design Contradiction:

Measurement precisionVSManufacturing precision

Solution Approach 1:

The support member is divided into multiple recesses, each accommodating a sensor. This segmentation allows each sensor to be precisely positioned in its own dedicated space, ensuring consistent radial distance from the encoder washer while maintaining multiple detection points around the rotation axis.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The support member acts as an intermediary structure between the sensors and the encoder washer. It provides a stable mounting platform with controlled air gap, isolating the sensors from direct mounting errors and ensuring uniform positioning relative to the rotating encoder washer.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If sensors are mounted on a foldable printed circuit board in an outer body, then device flexibility is improved, but air gap consistency deteriorates due to mounting variations

Engineering Contradiction:

Improvemounting flexibilityVSAvoidair gap consistency

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The support member extends in the radial dimension to provide precise positioning of sensors at a consistent distance from the encoder washer. This radial extension ensures that sensors mounted on the support member maintain a controlled air gap, while the support member itself can be adapted to different mounting configurations.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Volume of moving object

If the rotation detection set uses a compact support member housing, then device size is reduced, but sensor positioning precision must be maintained

Engineering Contradiction:

Improvesupport member sizeVSAvoidsensor positioning accuracy

Core Design Contradiction:

Volume of moving objectVSManufacturing precision

Solution Approach 1:

The support member contains multiple recesses nested within its structure, each housing a sensor. This nested arrangement allows precise positioning of multiple sensors within a compact volume, maintaining accurate radial positioning while minimizing the overall size of the detection set.

Inventive Principle:

Principle #7Nested doll (Nesting)

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

This configuration enhances the accuracy of rotation detection by maintaining consistent air gaps between sensors and the encoder washer, reducing errors from sensor eccentricity and transverse movements, while keeping the support member compact and efficient.

Implementation Method 1

a magnetic body (24) which defines a series of magnetic poles arranged around the axis X20 in the form of alternating North and South poles N, S

Methodology Applied

Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

several sensors (48A to 48E) evenly distributed around the encoder washer and mounted onto a foldable printed circuit board

Methodology Applied

Scientific EffectHall effect: Hall Effect

Data Source

PatentEP2652447B1Detection set comprising a support member, manufacturing method of such a detection set and bearing assembly including such a detection set

Publication Date: 2018.11.28 AB SKF SKF PATENT DEPARTMENT

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AI summary

This support member (44) is for holding at least two sensors with respect to an encoder washer and forms one housing (V445) adapted to accommodate the sensors next to each other. This housing (V445) has at least two abutment surfaces (446, 447A-447E, 448A-448E) for positioning each of said sensors along two perpendicular directions (R2, R'2). The rotation detection set comprises an encoder washer adapted to rotate around a rotation axis, at least two sensors adapted to detect the rotation of the encoder washer around the rotation axis and a support member (44). The sensors are mounted in the housing (V445) of the support member and immobilized within the housing.