Torque-Driven Swivel Arm Machine Tool for Fast Stable Pivoting

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Solution Overview

Problem

Existing machine tools with pivoting arms require complex mechanisms and result in slower pivoting movements due to the need for multiple moving parts and increased risk of vibrations from high center of gravity when positioning the tool spindle.

Innovation Solution

A simplified machine tool design featuring a direct drive of the pivoting arm by a torque motor on a horizontal swivel axis, reducing the number of moving parts and stabilizing the center of gravity, allowing for faster and more precise pivoting movements with a five-axis capability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a spindle drive and lever mechanism are used to achieve swiveling movement of the swivel arm, then the machine tool can perform the swiveling movement, but the design becomes complex and the swiveling speed decreases

Engineering Contradiction:
Improvedesign complexityVSAvoidswiveling speed
Core Design Contradiction:
Device complexityVSSpeed

Solution Approach 1:

The patent removes the intermediate lever mechanism from the drive system, directly connecting the spindle drive to the swivel arm. This extraction of the unnecessary intermediate mechanism simplifies the design while enabling faster direct drive operation, resolving the contradiction between design complexity and swiveling speed.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of using a complex lever mechanism to achieve swiveling, the patent inverts the approach by using the spindle drive directly on the swivel axis. This inversion of the drive architecture eliminates the need for intermediate transmission components, achieving both simplicity and speed.

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

2Length of moving object

If the tool spindle is positioned on the swivel arm with a high center of gravity, then the tool spindle can reach upper positions, but vibrations increase and stability decreases

Engineering Contradiction:
Improvetool spindle position rangeVSAvoidvibration stability
Core Design Contradiction:
Length of moving objectVSStability of the object's composition

Solution Approach 1:

The patent positions the tool spindle such that its center of gravity remains low and close to the swivel axis throughout the range of motion. This counteracts the gravitational torque that would otherwise cause vibrations, maintaining stability while achieving full positional range.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The design ensures that the center of gravity of the tool spindle assembly remains at a constant low position relative to the swivel axis during rotation, creating an equipotential gravitational field that eliminates vibrational tendencies throughout the motion range.

Inventive Principle:
Principle #12Equipotentiality

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 design enables faster and more precise pivoting of the tool spindle with reduced vibrations, enhancing machining efficiency and stability, particularly suitable for machining large and heavy workpieces like blisks.

Implementation Method 1

The direct drive of the swivel arm 6 by a torque motor arranged on the swivel axis 7 allows for fast and precise movements of the tool spindle 8

Methodology Applied
Scientific EffectDirect drive:

Implementation Method 2

The horizontal movements of the swivel arm 6 on the second linear guide 2 are preferably performed by a linear motor

Methodology Applied
Scientific EffectLinear motor: Linear Motor

Implementation Method 3

The plain bearing 22 provides vibration damping through its oil film (squeeze film damping)

Methodology Applied
Scientific EffectVibration damping: Damping

Implementation Method 4

A ball screw, for example, is provided for the horizontal movement of the workpiece clamping device 3 on the first linear guide 1

Methodology Applied
Scientific EffectBall screw: Screw

Data Source

PatentEP3434412B1Machine tool
Publication Date: 2022.12.21 GF MACHINING SOLUTIONS AG
  • EP3434412B1 patent drawingFigure 1~2
  • EP3434412B1 patent drawingFigure 3

AI summary

The machine tool has a machine bed (10) with a first horizontal linear guide (1) and a second horizontal linear guide (2) arranged perpendicular to the first linear guide (1). A workpiece clamping device (3) is axially displaceable on the first linear guide (1). It is pivotable about a pivot axis (4) oriented parallel to the second linear guide (2) and rotatable about a rotary axis (5) oriented perpendicular to the pivot axis (4). A swivel arm (6) is axially displaceable on the second linear guide (2). The swivel axis (7) of the swivel arm is parallel to the first linear guide (1), and the free end of the swivel arm carries a tool spindle (8) whose axis (9) is oriented parallel to the first linear guide (1). The swivel arm (6) is pivotable by means of a torque motor arranged on its pivot axis (7).