Rotating Shaft Misalignment Sensing With Collar-Mounted Sensors

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Solution Overview

Problem

Existing methods for measuring misalignment of rotating shafts are inadequate due to sensor dislodgment, limited space for internal sensors, and damage or failure of strain gauges.

Innovation Solution

A system comprising a rotating shaft with first and second couplings and a sensor assembly, where sensors are mounted on a collar that rotates with the shaft, measuring changes in distance to the couplings' rims to determine misalignment angles, allowing for continuous measurement without the need for external sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If external sensors are used to measure shaft misalignment, then measurement capability is provided, but sensors become dislodged during rotation

Engineering Contradiction:

Improveshaft misalignment measurementVSAvoidsensor dislodgment

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The sensor assembly is merged with the shaft by mounting the sensor on a collar that rotates with the shaft. This integration ensures the sensor moves with the shaft during rotation, eliminating dislodgment issues while maintaining continuous misalignment measurement capability.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The measurement approach transitions from external stationary sensors to a rotating sensor system that changes position dynamically with shaft rotation. The sensor measures distance to the coupling rim at different angular positions, using dimensional changes during rotation to determine misalignment angles.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If internal sensors are used within the shaft, then sensor protection is improved, but space for sensors is limited

Engineering Contradiction:

Improvesensor protectionVSAvoidspace for sensors

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

The sensor assembly is nested on the exterior surface of the shaft through a collar that fits over the shaft. This nested configuration protects the sensor while utilizing the shaft's external surface area, avoiding the space constraints of internal mounting while maintaining sensor security during rotation.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Measurement precision

If strain gauges are incorporated with sensors, then measurement capability is enhanced, but damage or failure occurs

Engineering Contradiction:

Improvemisalignment measurementVSAvoidsensor damage or failure

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The system replaces strain gauges with a distance-measuring sensor that detects the position of the coupling rim relative to the sensor. This substitution eliminates the mechanical strain gauge vulnerability to damage while maintaining measurement capability through optical or electromagnetic distance detection.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Loss of information

If shaft misalignment is measured during operation, then real-time data is obtained, but measurement complexity increases

Engineering Contradiction:

Improvereal-time misalignment dataVSAvoidmeasurement system complexity

Core Design Contradiction:

Loss of informationVSDevice complexity

Solution Approach 1:

The sensor measures distance to the coupling rim at periodic intervals during shaft rotation. By sampling the distance at specific angular positions and using the periodic nature of rotation, the system determines misalignment angles through straightforward calculations based on the measured distance variations throughout the rotation cycle.

Inventive Principle:

Principle #19Periodic action

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 accurate and reliable measurement of shaft misalignment, reducing the risk of sensor dislodgment and damage, and providing real-time data on misalignment without requiring disassembly or reassembly.

Implementation Method 1

A light-weight sensor or sensors are attached to the non-flexing portion of a flexible driveshaft to measure a degree of misalignment between the shaft and a coupling

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentUS11248897B2Method of measuring misalignment of a rotating flexible shaft assembly

Publication Date: 2022.02.15 GOODRICH CORP

AI summary

A method for sensing misalignment of a rotating shaft includes rotating the shaft. A distance from a sensor on the shaft to a first rim of a first coupling mounted to an end of the shaft is sensed as the shaft rotates. A change in the distance from the first sensor to the first rim of the first coupling is determined based on the sensed distance. An angle of the first coupling based on the change in the distance from the first sensor to the first rim of the first coupling during one revolution of the shaft is determined based on the sensed change in the distance from the first sensor to the first rim. An angle of the shaft is determined based on the sensed distance from the first sensor to the first rim of the first coupling representing the sensed change in the distance from the first sensor to the first rim.