Flexible Coupling Vibration Filtering in Measuring Machines

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Solution Overview

Problem

Existing measuring machines face challenges in reducing vibrations and orthogonal forces, which affect measuring accuracy and require high-quality components and precise alignment, limiting measuring speed and increasing costs.

Innovation Solution

A transmission system using a flexible coupling with helical springs and a control system that includes feedback and open-loop components to filter vibrations and maintain precise motion, allowing for lighter structural elements and improved metrological performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a rigid connection is used between motor and mobile member, then transmission of motion is reliable, but vibrations and orthogonal forces are transmitted to the mobile member, reducing measuring accuracy

Engineering Contradiction:
Improvemotion transmission reliabilityVSAvoidmeasuring accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

A flexible coupling device is introduced as an intermediary element between the motor-driven transmission system and the mobile member. This coupling comprises elastic elements (springs) that mechanically connect the drive belt to the mobile member, allowing motion transmission while filtering vibrations and orthogonal forces through the elastic deformation of the springs.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The connection stiffness parameter is changed from rigid (infinite stiffness) to flexible (finite stiffness determined by spring characteristics). The spring constant and precompression force are optimized to provide sufficient motion transmission while attenuating high-frequency vibrations and blocking orthogonal forces, thus improving measuring accuracy without sacrificing motion reliability.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If high-quality components and precise alignment are used, then measuring accuracy is improved, but device complexity and costs increase

Engineering Contradiction:
Improvemeasuring accuracyVSAvoidtransmission system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The flexible coupling with elastic elements serves as a vibration-filtering intermediary that passively reduces vibrations and orthogonal forces without requiring complex active control systems or high-precision component specifications. This simplifies the overall system while maintaining or improving measuring accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The flexible coupling uses simple elastic elements (springs) that are inexpensive and can be easily replaced if needed, replacing the need for expensive high-precision transmission components and complex alignment procedures.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Measurement precision

If high-quality components and precise alignment are used, then measuring accuracy is improved, but measuring speed is limited

Engineering Contradiction:
Improvemeasuring accuracyVSAvoidmeasuring speed
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The flexible coupling parameters (spring constant, precompression force) are optimized to allow rapid acceleration and deceleration of the mobile member while maintaining vibration filtering performance. This enables higher measuring speeds without compromising accuracy by allowing the system to respond quickly to control commands while the elastic elements continue to filter out harmful vibrations.

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

The solution effectively reduces vibrations and orthogonal forces, enhancing measuring accuracy, enabling higher speeds or reduced costs with lighter components, while maintaining precise motion control.

Implementation Method 1

The connection between the motor and the mobile member is made by means of a flexible coupling, which comprises elastic elements, in particular springs

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The flexible coupling includes a spring member which preloads the cage with respect to the carriage, the preload being set to a value which compensates for the weight of measuring sleeve

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP2623923B1Measuring machine provided with an improved transmission system
Publication Date: 2018.04.11 HEXAGON METROLOGY SPA
  • EP2623923B1 patent drawingFigure 1
  • EP2623923B1 patent drawingFigure 2~3
  • EP2623923B1 patent drawingFigure 4

AI summary

A measuring machine (1) comprising at least one member (5) mobile along an axis (Y), a motor (15), a transmission system (14) driven by the motor (15) for displacing the mobile member (5) along the axis (Y), and a control system (44) for controlling the motor (15), wherein a flexible coupling (35) is set between said transmission system (14), and the mobile member (5) is configured so as to filter the vibrations transmitted by the transmission system (14) to the mobile member (5) in the direction of the axis (Y) and to decouple the mobile member (5) from the transmission system (14) in a direction transverse to the axis (Y).