Rotary Position Sensor Isolator Vibration Damping

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Solution Overview

Problem

Rotary position sensors in applications like combine harvesters are prone to wear and damage due to vibration and movement, with existing solutions relying on internal return springs that absorb these forces, leading to potential damage and reduced accuracy.

Innovation Solution

The introduction of a separate torsion spring that resiliently biases the torque coupling surface of the linkage against the torque coupling surface of the first member, independent of the torque receiving component, to absorb vibrations and reduce wear on the rotary position sensor, thereby eliminating the need for an internal return spring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an internal return spring is used to absorb vibration and movement forces, then the sensor can maintain contact between torque coupling surfaces, but the spring itself becomes susceptible to wear and damage, reducing overall system reliability

Engineering Contradiction:
Improvesensor reliabilityVSAvoidvibration and movement forces
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention separates the vibration absorption function from the torque transmission function by introducing a distinct isolator component with damping elements, rather than relying on the return spring to perform both functions. This segmentation allows the torque coupling surfaces to remain in constant contact while vibration forces are absorbed by dedicated damping material.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The isolator acts as an intermediary component between the first member and the linkage, providing a medium that transmits torque while filtering out vibration and movement forces. The damping material within the isolator absorbs harmful forces before they reach the sensor, protecting the torque coupling surfaces from wear.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If torque coupling surfaces are kept in constant contact to eliminate play gap, then measurement precision improves, but wear and damage increase due to continuous friction from vibration and movement

Engineering Contradiction:
Improveangular positioning accuracyVSAvoidwear and damage from friction
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The invention converts the harmful effect of vibration and movement forces into a beneficial filtering process. The damping material absorbs these forces, transforming what would be damaging friction into protective energy dissipation, while maintaining constant contact between torque coupling surfaces for accurate measurement.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The invention changes the physical state and properties of the isolator component, using damping material with specific viscoelastic properties that allow it to deform under vibration forces while maintaining torque transmission. This parameter change enables the system to maintain surface contact while reducing wear through material selection.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If a separate isolator component is introduced to protect the sensor, then reliability and precision improve, but device complexity increases

Engineering Contradiction:
Improvesensor protectionVSAvoidnumber of components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention merges multiple functions into the isolator component: vibration absorption, torque transmission, and maintenance of constant contact between torque coupling surfaces. By combining these functions into a single integrated component rather than adding separate mechanisms, the increase in complexity is minimized while achieving the desired protection and precision.

Inventive Principle:
Principle #5Merging (Combining)

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 solution reduces wear and damage to the rotary position sensor by isolating it from vibration and movement, providing more precise and reliable angular positioning and rotation sensing without relying on internal springs, resulting in a more robust sensing system.

Implementation Method 1

the input shaft is coupled to the rotational shaft through a rotation transmitting means, wherein the rotation transmitting means permits the axis of the input shaft to become offset from the axis of the rotational shaft by its elastic deformation

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

a separate torsion spring that resiliently biases the torque coupling surface of the linkage against the torque coupling surface of the first member, independent of the torque receiving component, to absorb vibrations and reduce wear

Methodology Applied
Scientific EffectVibration absorption: Damping

Data Source

PatentEP3575622B1Rotary position sensor isolator
Publication Date: 2021.01.20 DEERE & CO
  • EP3575622B1 patent drawingFigure 1~3
  • EP3575622B1 patent drawingFigure 4~5
  • EP3575622B1 patent drawingFigure 6~7

AI summary

A rotary position sensor (22) senses rotation of a first member (24), having a first torque coupling surface, about an axis (28) relative to a second member (26) by sensing movement of a torque receiving component (30) of the rotary. The isolator (20) may include a mount (40), a linkage (42) and a torsion spring (50). The linkage is to be coupled to the torque receiving component (30) of the rotary sensor (22). The linkage has a second torque coupling surface separable from the first torque coupling surface by a play gap, wherein during rotation of the first member, the first torque coupling surface is to contact the second torque coupling surface to transmit torque to the linkage. The torsion spring (50) is captured between the mount (40) and the linkage (42) independent of the torque receiving component (30) to resiliently bias the second torque coupling surface through the play gap and into engagement with the first torque coupling surface.