Spindle Lock Design for Balancing Accuracy

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Solution Overview

Problem

Existing balancing machines face challenges in accurately determining and eliminating rotational imbalances of tool holders without causing measurement inaccuracies due to clamping and material removal processes, which can affect sensor sensitivity and spindle movement.

Innovation Solution

A spindle lock design that fixes the spindle unit without affecting the spindle suspension or sensitive sensors, using clamping strips with flexible components to absorb forces and allow precise material removal without shifting the spindle, enabling accurate balancing without clamping-induced inaccuracies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If clamping jaws are applied to the spindle unit from two sides to prevent unwanted movements during machining, then the spindle unit is fixed against forces from clamping and material removal, but the spindle suspension and sensors are strained leading to measurement inaccuracies

Engineering Contradiction:
Improvespindle unit stabilityVSAvoidmeasurement accuracy
Core Design Contradiction:
Stability of the object's compositionVSMeasurement precision

Solution Approach 1:

The clamping device is divided into multiple independent clamping elements (at least two clamping elements) that can be applied to different locations on the spindle unit. Each clamping element independently absorbs forces from specific directions, preventing force transmission to the spindle suspension while maintaining overall spindle stability during machining operations.

Inventive Principle:
Principle #1Segmentation

2Stability of the object's composition

If a clamping device acts directly on the spindle unit to prevent pivoting or translational movements, then the spindle unit is rigidly fixed, but the spindle cannot rotate which prevents certain material removal operations

Engineering Contradiction:
Improvespindle unit fixationVSAvoidspindle rotation capability
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The clamping device is designed with flexible or resilient clamping elements that can dynamically adapt to spindle rotation. The clamping elements maintain contact with the spindle unit while allowing rotational movement, enabling both stable fixation during machining and the capability to perform rotary material removal operations when needed.

Inventive Principle:
Principle #15Dynamics

3Ease of manufacture

If the tool holder is removed from the balancing machine for material removal, then the tool holder can be clamped and unclamped for balancing, but clamping and unclamping takes time and affects measurement accuracy due to position changes

Engineering Contradiction:
Improvematerial removal capabilityVSAvoidmeasurement accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The spindle unit is pre-equipped with a specialized clamping device that maintains stable fixation during the entire machining process without requiring removal and re-clamping. This preliminary setup eliminates the need to detach and re-attach the tool holder, preventing position changes that would compromise measurement accuracy while enabling efficient material removal operations.

Inventive Principle:
Principle #10Preliminary action

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 spindle lock ensures measurement accuracy by isolating forces from the spindle suspension and sensors, allowing for precise material removal and improved balancing quality by maintaining the spindle's position and preventing unwanted movements during machining.

Implementation Method 1

using clamping strips with flexible components to absorb forces

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2483655B1Spindle clamping
Publication Date: 2020.02.12 FRANZ HAIMER MASCHINENBAU KG
  • EP2483655B1 patent drawingFigure 1
  • EP2483655B1 patent drawingFigure 2
  • EP2483655B1 patent drawingFigure 3

AI summary

The invention relates to a balancing device, having a measuring system for determining the rotational unbalance of a test object, comprising a spindle unit with a spindle, which is intended to hold the test object and rotate it at a test rotational speed, and a spindle mounting, by which the spindle unit is movably anchored on the machine base, such that the spindle unit can oscillate in a predetermined measuring direction as a result of the unbalance forces occurring during the measurement operation, and at least one sensor, which upon rotation of the spindle detects at least one unbalance characteristic variable occurring in the measuring direction, and a material removal system for balancing the test object by material removal in a predetermined site. The measuring system and the material removal system are designed such that material can be removed when the test object is held in the spindle.