Angle Sensor Drive Gear Radial Positioning

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Solution Overview

Problem

Existing angle sensors face measurement inaccuracies due to hysteresis errors caused by play between drive and target gears, which cannot be fully compensated without deviating the axes of rotation of target gears, leading to significant measurement errors.

Innovation Solution

The drive gear wheel is pressed into a defined radial position by a resiliently acting element within its bearing, allowing the axis of rotation to be fixed independently of its position, and a transmission element with spring-elastic properties ensures play-free contact with the shaft, compensating for deviations and maintaining accurate alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If resilient bearing elements are used to couple measuring gears to the drive gear, then static and dynamic deviations of the shaft axis can be compensated, but the axes of rotation of the target wheels deviate from their ideal positions causing measurement errors

Engineering Contradiction:
Improvecompensation of shaft axis deviationsVSAvoidmeasurement accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent separates the functions of compensating shaft deviations and maintaining target wheel positioning accuracy. The resilient bearing elements compensate for shaft axis deviations, while a separate positioning mechanism (precision bearings or locating elements) ensures target wheels maintain their ideal rotational positions relative to the sensor elements, preventing measurement errors.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary positioning mechanism between the resilient bearing elements and the target wheels. This intermediary structure (such as precision bearings or locating features) decouples the compensation function from the positioning function, allowing the target wheels to maintain accurate positions even while the resilient elements absorb shaft deviations.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If play between drive and target gears is reduced, then hysteresis error is reduced, but the axes of rotation of target gears must be fixed which can lead to measurement errors when they deviate

Engineering Contradiction:
Improvereduction of hysteresis errorVSAvoidstability of axis alignment
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent employs resilient bearing elements that provide dynamic adaptation to shaft position variations while maintaining stable target wheel positions. These elements allow the system to dynamically compensate for shaft deviations without creating play between the drive gear and target gears, thus reducing hysteresis error while maintaining measurement reliability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the mechanical parameters of the bearing elements to optimize both play reduction and position stability. By carefully selecting the stiffness and preload of the resilient bearing elements, the system achieves minimal play between gears (reducing hysteresis) while maintaining stable rotational positions of target wheels (ensuring measurement reliability).

Inventive Principle:
Principle #35Parameter changes

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 significantly reduces hysteresis errors while maintaining precise alignment of target gears, enhancing measurement accuracy without introducing noise or axis deviation issues.

Implementation Method 1

the drive gear wheel is pressed by at least one resiliently acting element into a defined radial position within its bearing

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

A transmission element, which has spring-elastic properties and is accommodated under elastic pretension between the shaft and the drive gear wheel, causes play-free contact of the drive gear wheel with the shaft in every rotational position of the shaft

Methodology Applied
Scientific EffectSpring-elastic properties: Spring

Data Source

PatentEP2585799B1Angle sensor
Publication Date: 2018.09.26 LEOPOLD KOSTAL GMBH & CO KG
  • EP2585799B1 patent drawingFigure 1
  • EP2585799B1 patent drawingFigure 2

AI summary

Angle sensor for sensing the rotary position of a rotatable shaft, comprising a driving gear that is connected to the shaft in a torque-transmitting manner, and at least one measuring gear that is directly driven by the driving gear, the driving gear and the at least one measuring gear being mounted in a sensor housing, and the angular position of the shaft being determined from the angular position of the measuring gear/s. According to the invention, said angle sensor is characterized in that at least one resilient element exerts a force onto the driving gear, thereby forcing it into a defined radial position in the bearing.