Angle Sensor Drive Gear Resilient Coupling for Axis Deviation Compensation

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Solution Overview

Problem

Existing angle sensors for detecting the rotational position of a rotatable shaft suffer from measurement errors due to static and dynamic deviations in the axis of rotation, which are not adequately compensated by previous designs that allow target wheels' axes to deviate from their ideal position.

Innovation Solution

The angle sensor employs two radially extending carriers on the drive gear wheel that engage with a bearing ring connected to the shaft, allowing for the fixation of the drive gear's axis of rotation and compensating for deviations by using a resiliently flexible driver with spring arms to maintain precise alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If target wheels are coupled backlash-free to the drive gear wheel via resilient bearing elements to compensate for axis deviations, then the ability to compensate for static and dynamic deviations is improved, but measurement errors increase due to deviation of target wheel axes from their ideal position

Engineering Contradiction:
Improvecompensation capability for axis deviationsVSAvoidangular position detection accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent inverts the traditional approach by making the drive gear wheel resiliently flexible instead of making the target wheels resilient. The drive gear wheel is mounted resiliently on the shaft, while the target wheels are rigidly connected to the drive gear wheel. This inversion allows the system to compensate for axis deviations while maintaining fixed, precise axes for the target wheels, thereby resolving the measurement error problem.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent segments the resilient mounting function from the target wheels and applies it to the drive gear wheel instead. The drive gear wheel is divided into a resiliently mounted portion (on the shaft) and a rigid portion (connecting to target wheels). This segmentation allows the resilient element to handle axis deviations while the rigid connection ensures precise angular position transmission without measurement errors.

Inventive Principle:
Principle #1Segmentation

2Reliability

If the axis of rotation of the shaft deviates from the ideal position statically or dynamically, then the resilient coupling compensates for the deviation, but the axes of rotation of the target wheels also deviate leading to measurement errors

Engineering Contradiction:
Improvecompensation for shaft axis deviationsVSAvoidangular position measurement accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent applies the resilient mounting to the drive gear wheel rather than to the target wheels. This inversion ensures that the resilient element compensates for shaft axis deviations at the drive gear level, while the target wheels maintain their ideal fixed axes relative to the drive gear wheel, eliminating measurement errors caused by target wheel axis deviation.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The drive gear wheel acts as an intermediary between the resiliently mounted shaft and the rigidly connected target wheels. The resilient mounting on the drive gear wheel absorbs axis deviations, while the rigid connection from the drive gear wheel to the target wheels ensures that the target wheels maintain precise, fixed axes for accurate measurement.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If a permanent magnet in a target wheel moves relative to the Hall sensor due to axis deviation, then the resilient coupling absorbs the deviation, but additional relative movement occurs causing measurement errors

Engineering Contradiction:
Improveabsorption of axis deviationsVSAvoidmagnetic field detection accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent inverts the resilient mounting location to the drive gear wheel, which ensures that the permanent magnets in the target wheels maintain their correct angular positions relative to the Hall sensors. The resilient drive gear wheel absorbs axis deviations, preventing additional relative movement between the magnets and sensors, thereby eliminating measurement errors.

Inventive Principle:
Principle #13The other way round (Inversion)

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 effectively fixes the axes of rotation, reducing measurement errors and ensuring accurate detection of the shaft's rotational position by compensating for static and dynamic deviations, thereby enhancing the precision of the angle sensor.

Implementation Method 1

at least one of the carriers being resiliently flexible in the circumferential direction is trained. In an advantageous embodiment, a driver is rigid and the driver, which is resiliently flexible in the circumferential direction, is provided with integrally formed small spring arms which, preferably in the rest position, bear slightly prestressed on the two edges of the associated recess of the bearing ring.

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2422164B1Angle sensor
Publication Date: 2014.10.01 LEOPOLD KOSTAL GMBH & CO KG
  • EP2422164B1 patent drawingFigure 1
  • EP2422164B1 patent drawingFigure 2

AI summary

Disclosed is an 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 angular position of the shaft can be determined from the angular position of the measuring gear/s. According to the invention, said angle sensor is characterized in that the driving gear has two entraining elements which lie opposite each other relative to the circumference of the driving gear, extend in the radial direction relative to the axis of rotation, and engage into associated recesses of a bearing ring that is rigidly connected to the shaft. At least one of the entraining elements is designed to be resilient in the circumferential direction.