Linear Axis Carriage Compensation for Rail Misalignment

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Solution Overview

Problem

Linear guiding systems face misalignment issues due to thermal expansion and mechanical inaccuracies, leading to operational constraints, hardware wear, and reduced guiding accuracy, which are costly and time-consuming to address.

Innovation Solution

A deviation compensating device is introduced, mechanically connecting the carriage to the slider using resilient attaching means that allow vertical and horizontal movement, enabling pivot and displacement adjustments to compensate for misalignment and thermal expansion, utilizing elastic fastening means and bearing components for stable contact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If accurate positioning of guiding rails is used, then guiding accuracy is improved, but assembly time and cost increase

Engineering Contradiction:
Improveguiding accuracyVSAvoidassembly time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The invention changes the rigidity parameter of the connection between carriage and sliders by introducing resilient attaching means with elastic fastening elements. This allows the system to adapt to rail misalignment without requiring precise positioning, thereby reducing assembly time while maintaining guiding accuracy through elastic compensation rather than rigid precision mounting.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention transforms the static rigid connection into a dynamic resilient connection that can adapt to varying conditions. The elastic fastening means allow the carriage to pivot and move relative to sliders, enabling real-time compensation for rail misalignment and thermal expansion, thus eliminating the need for time-consuming precise positioning during assembly.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If accurate positioning of guiding rails is used, then guiding accuracy is improved, but assembly cost increases

Engineering Contradiction:
Improveguiding accuracyVSAvoidassembly cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

By changing the connection rigidity parameter to resilient, the invention eliminates the need for expensive accurate substructures and positioning equipment. The elastic fastening means provide a cost-effective solution that compensates for rail misalignment through material elasticity rather than expensive precision mounting hardware.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses simple elastic fastening elements (springs, elastomers) that are inexpensive compared to expensive positioning equipment and accurate substructures. These resilient attaching means provide effective compensation at low cost, replacing expensive precision mounting solutions.

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

3Stability of the object's composition

If rigid connection between carriage and sliders is used, then structural stability is improved, but thermal expansion compensation capability deteriorates

Engineering Contradiction:
Improvestructural stabilityVSAvoidthermal expansion compensation
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The invention transforms the static rigid connection into a dynamic resilient connection. The elastic fastening means allow the carriage to pivot around the longitudinal axis and move along the transversal axis, enabling real-time adaptation to thermal expansion and rail misalignment while maintaining stable operational connection between carriage and sliders.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The resilient attaching means act as an intermediary between the carriage and sliders, providing both structural stability through elastic connection and thermal expansion compensation through controlled flexibility. The bearing means serve as intermediaries that maintain stable contact while allowing necessary movements.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Adaptability or versatility

If resilient attaching means with movement capability is used, then thermal expansion compensation is improved, but device complexity increases

Engineering Contradiction:
Improvethermal expansion compensationVSAvoidconnection structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The invention segments the connection function into distinct elements: elastic fastening means for providing resilient attachment and enabling movement, and bearing means for maintaining stable contact. This segmentation allows each component to perform its specific function simply, avoiding the need for complex integrated mechanisms while achieving thermal expansion compensation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

By changing the connection from rigid to resilient using simple elastic elements, the invention achieves thermal expansion compensation without complex mechanisms. The elastic fastening means and bearing means provide the necessary movement capability through straightforward elastic deformation and bearing contact rather than complex mechanical linkages.

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 solution provides a cost-effective and efficient method to maintain system alignment, reducing mechanical constraints and wear, while allowing for thermal expansion compensation, thereby enhancing the operational accuracy and reliability of linear guiding systems.

Implementation Method 1

The resilient attaching means comprise a first set of elastic fastening means vertically biasing said carriage lower part against said slider upper part

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

Thermal expansion is not homogenous for all components of the substructure and of the gantry due to different materials or temporary different component temperatures

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP4036429B1Deviation compensation integrated in the carriage of a linear axis
Publication Date: 2024.11.20 NTN WAELZLAGER (DEUTSCHLAND) GMBH
  • EP4036429B1 patent drawingFigure 1~2
  • EP4036429B1 patent drawingFigure 3A~3B
  • EP4036429B1 patent drawingFigure 4A~4B

AI summary

The invention relates to a linear guiding system (1) comprising a carriage (4) mechanically connected by a deviation compensating device to at least one slider (7) slidably mounted on linear guiding means (10). The deviation compensating device comprises resilient attaching means for connecting a slider upper part (9) to a carriage lower part (5) opposite to said slider upper part (9). The resilient attaching means comprise a first set of elastic fastening means (8, 14) vertically biasing said carriage lower part (5) against said slider upper part (9) with bearing means (18, 18a) located between said carriage lower part (5) and said slider upper part (9). Thereby, said carriage (4) can pivot relatively to said slider (7) at least around a longitudinal axis (X) of said linear guiding means (1). The resilient attaching means comprise further a second set of elastic fastening means (23, 24, 25) horizontally biasing said carriage lower part (5) against said slider (7). Thereby, said carriage (1) can move relatively to said slider (7) at least along a horizontal transversal axis (Y) substantially perpendicular to said longitudinal axis (X). Said carriage lower part (5) is integrally formed with the carriage (4) or mechanically fixed to said carriage (4).