Exchangeable Spindle Unit for Machine Tool Maintenance

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Solution Overview

Problem

The existing tool spindles in machine tools are complex to service, prone to operational errors, and have reliability issues during long-term operation, requiring skilled personnel and involving extensive dismantling and reassembly, which can lead to increased downtime and reduced service life.

Innovation Solution

The tool spindle is designed as an exchangeable spindle unit that can be easily removed and replaced by loosening the spindle flange, eliminating the need for electrical or fluid-technical work during service, with a sealing bolt system ensuring reliable coolant transfer and reducing the complexity of maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the tool spindle is designed as a complex integrated unit with motor, bearings, and clamping system, then the machining precision and reliability are improved, but the service complexity and downtime increase

Engineering Contradiction:
Improvespindle reliabilityVSAvoidspindle service complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The spindle is divided into modular components: a reusable spindle housing (spindle head) and an exchangeable spindle unit containing the motor, bearings, and clamping system. This segmentation allows the complex spindle unit to be quickly replaced without dismantling the housing, reducing service complexity while maintaining the reliability benefits of the integrated design.

Inventive Principle:
Principle #1Segmentation

2Loss of time

If the spindle unit is exchanged as a complete assembly, then the service time is reduced, but the cost increases due to replacing functional components

Engineering Contradiction:
Improvemaintenance timeVSAvoidcomponent waste
Core Design Contradiction:
Loss of timeVSLoss of substance

Solution Approach 1:

By segmenting the spindle into a reusable housing and an exchangeable unit, only the necessary components (spindle unit) are replaced when defective, while functional housings remain in service. This reduces both maintenance time and component waste compared to replacing the entire spindle assembly.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The exchangeable spindle unit is designed as a disposable or recoverable component that is replaced when defective, while the valuable spindle housing is recovered and reused. This approach minimizes waste of functional components and reduces maintenance costs.

Inventive Principle:
Principle #34Discarding and recovering

3Ease of repair

If the spindle housing is constructed in two parts for easier service, then the dismantling work is reduced, but the structural complexity and potential leakage points increase

Engineering Contradiction:
Improvespindle accessibilityVSAvoidhousing structure complexity
Core Design Contradiction:
Ease of repairVSDevice complexity

Solution Approach 1:

The spindle housing is divided into a stationary housing and an exchangeable spindle unit that can be independently removed. This segmentation provides easy access to the spindle components without requiring the housing itself to be dismantled, reducing repair complexity while avoiding the issues of multi-part housing construction.

Inventive Principle:
Principle #1Segmentation

4Reliability

If skilled specialists perform the service work, then the error rate is reduced, but the service cost and availability increase

Engineering Contradiction:
Improveservice qualityVSAvoidservice accessibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The exchangeable spindle unit is designed as a self-contained module that can be replaced without requiring skilled specialists to perform complex dismantling and reassembly operations. This simplifies the service task to a straightforward exchange operation that can be performed by less specialized personnel, improving service accessibility while maintaining reliability.

Inventive Principle:
Principle #1Segmentation

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 design significantly reduces the time and complexity of maintenance, allowing for quick replacement of defective units, minimizing downtime, and providing a cost-effective solution by only replacing necessary components, while ensuring reliable operation and improved sealing to prevent leaks.

Implementation Method 1

a sealing bolt which can be rotated about the axis of rotation and which engages in a coolant channel that is provided centrally to the axis of rotation in the spindle unit

Methodology Applied
Scientific EffectSealing:

Data Source

PatentEP2433741B1Machine tool with exchangeable spindle unit
Publication Date: 2013.06.19 STAMA MASCHFAB GMBH
  • EP2433741B1 patent drawingFigure 1
  • EP2433741B1 patent drawingFigure 2
  • EP2433741B1 patent drawingFigure 3

AI summary

The machine tool has a tool retainer (28) arranged in a tool spindle, where the tool spindle is rotatable around a rotational axis (32) and supported in a spindle housing. The tool spindle is formed as an interchangeable spindle unit (61) and exchangeably fixed at the spindle housing by a spindle flange. A delivery device for fluid is provided in the spindle housing, and a seal bolt is supported at the delivery device, where the seal bolt is rotatable around the rotational axis and engages in a coolant channel (88).