5-Axis Gantry Machine Structure With Vertical Beam Thermal Stability

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Solution Overview

Problem

Conventional gantry machine tools are tall and thermally sensitive, leading to positioning accuracy losses due to temperature gradients, requiring costly temperature control measures.

Innovation Solution

A compact machine structure with a base and parallel linear guides on side walls, where a beam driven by motors moves vertically, eliminating the need for a Z-column and enhancing thermal stability by enclosing all 5 axes within a symmetric structure, with linear motors and cooling channels to manage heat.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a conventional mono-gantry machine structure with Z-column is used, then the machine can achieve precise positioning, but the machine height becomes large and thermal stability deteriorates

Engineering Contradiction:
Improvepositioning accuracyVSAvoidmachine height
Core Design Contradiction:
Measurement precisionVSLength of stationary object

Solution Approach 1:

The patent removes the Z-column from the machine structure, extracting the problematic vertical support element that caused height and thermal stability issues. The Z-column movement function is redistributed to individual column actuators, eliminating the need for a separate movable Z-column while maintaining positioning capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent segments the Z-axis movement function from a single Z-column into independent actuators on each column. This segmentation allows the beam to move vertically relative to fixed columns, eliminating the need for a tall Z-column while distributing the movement function across multiple smaller components.

Inventive Principle:
Principle #1Segmentation

2Shape

If a tall machine structure is used, then the machine can accommodate large workpieces, but temperature gradients increase and positioning accuracy is lost

Engineering Contradiction:
Improvemachine structure heightVSAvoidpositioning accuracy
Core Design Contradiction:
ShapeVSManufacturing precision

Solution Approach 1:

The patent changes the dimensional arrangement by moving the beam vertically in the Z-direction while keeping columns fixed. This dimensional reorganization allows the machine to achieve the necessary working envelope without increasing overall structure height, thereby reducing temperature gradients and improving thermal stability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Ease of operation

If a Z-column is included in the machine design, then vertical movement is achieved, but the machine becomes more sensitive to external temperature variation

Engineering Contradiction:
Improvevertical movement capabilityVSAvoidtemperature sensitivity
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the Z-column from the design, removing the component that was most susceptible to temperature variation. By distributing vertical movement to individual column actuators with fixed columns, the design eliminates the long vertical structure that acted as a thermal conduit.

Inventive Principle:
Principle #2Taking out (Extraction)

4Length of stationary object

If a compact machine structure is designed, then thermal stability is improved, but the complexity of coordinating motor movements increases

Engineering Contradiction:
Improvemachine heightVSAvoidmotor coordination system
Core Design Contradiction:
Length of stationary objectVSDevice complexity

Solution Approach 1:

The patent employs feedback control systems to coordinate the multiple motors driving the beam and columns. Sensors monitor positions and temperatures, and the control system adjusts motor commands in real-time to maintain synchronization and compensate for thermal effects, managing the complexity through intelligent control.

Inventive Principle:
Principle #23Feedback

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 reduces the machine's height, improves thermal stability, and maintains precision by synchronizing motor movements and balancing the machine head's weight, minimizing thermal gradients and bending moments, while maintaining machining stability and accuracy.

Implementation Method 1

In a preferred embodiment, each column is driven by a linear motor. The beam is driven by two brushless motors with ballcrew.

Methodology Applied
Scientific EffectLinear motor: Linear Motor

Implementation Method 2

with linear motors and cooling channels to manage heat

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 3

which may cause losses in positioning accuracy... costly air conditioning system

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3834984B1Machine structure for machine tool
Publication Date: 2024.02.07 GF MACHINING SOLUTIONS AG
  • EP3834984B1 patent drawingFigure 1~2
  • EP3834984B1 patent drawingFigure 3~4
  • EP3834984B1 patent drawingFigure 5~6

AI summary

The present invention is directed to a machine structure for a machine tool, in particular a 5-axis machine tool. The machine strucure comprises: a base, at least two linear guides arranged on the top surface of the base and positioned in parallel, a first column and a second column vertically mounted to the top surface of the base and configured to be movable on the at least two linear guides. The first column and the second column are connected by a beam, which can be driven by a motor such that the beam can be moved in the vertical direction.