Spindle Unit Cooling Circuit for Thermal Management

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Solution Overview

Problem

Existing motor spindle cooling systems, whether air or liquid based, face inefficiencies due to space requirements, thermal instability, and lack of adaptability to specific motor spindle types, leading to incomplete heat dissipation and malfunctions.

Innovation Solution

A compact spindle unit integrating a cooling circuit with inflow and outflow elements, allowing for a defined and optimized cooling medium flow directly within the spindle mount, utilizing a cooling unit that can be specifically adapted to the motor spindle, including a cooler with surface-enlarging structures and optional fan-assisted air cooling, and a liquid cooling medium with phase transition for enhanced heat transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If air cooling is used for motor spindles, then the structure is simple, but the heat dissipation capability is insufficient and large space is required

Engineering Contradiction:
Improvecooling system structureVSAvoidheat dissipation capability
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The patent transitions from air cooling to liquid cooling by introducing a cooling circuit with coolant flow. The liquid cooling medium is pumped through channels in the spindle housing, enabling efficient heat transfer from the motor spindle to the coolant, thereby resolving the insufficient heat dissipation capability while maintaining structural simplicity through integrated cooling channels.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent integrates the cooling unit directly into the spindle housing structure, moving from external air cooling to internal liquid cooling pathways. This dimensional integration allows the cooling system to occupy minimal space within the existing spindle structure while dramatically improving heat dissipation efficiency through direct liquid contact with heat-generating components.

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

2Loss of energy

If external cooling units are used independent of the motor spindle, then the cooling capacity is high, but the adaptability to specific spindle types is poor and the system complexity increases

Engineering Contradiction:
Improvecooling capacityVSAvoidadaptability to motor spindle type
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

The patent merges the cooling unit with the motor spindle housing to form an integrated spindle unit. The cooling circuit is built into the housing structure itself, with coolant channels directly contacting the motor spindle. This integration ensures high cooling capacity while maintaining perfect adaptability to the specific spindle type, as the cooling system is customized during manufacturing for each spindle configuration.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated cooling circuit design allows the same housing structure to serve both mechanical support and thermal management functions. The cooling system is designed to accommodate different motor spindle configurations while maintaining effective heat dissipation, thereby achieving both high cooling capacity and versatility across different spindle types.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Volume of moving object

If cooling units are located far away from the motor spindle, then the spindle unit is compact, but the thermal control precision is reduced

Engineering Contradiction:
Improvespindle unit sizeVSAvoidthermal control precision
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The patent nests the cooling unit within the motor spindle housing structure. The coolant channels are embedded directly in the housing, placing the cooling medium in immediate proximity to the heat-generating motor spindle components. This nested arrangement achieves compact spindle unit dimensions while maintaining excellent thermal control precision through direct, short-distance heat transfer pathways.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 provides efficient, space-efficient, and adaptable cooling, ensuring optimal thermal management and preventing malfunctions by allowing precise thermal control and reduced space requirements within the machine tool.

Implementation Method 1

a cooling circuit (4, 5) which is designed in a closed circuit and allows for a defined circuit of the cooling medium... transporting the cooling medium between a heat absorber (33) of the motor spindle (2) for absorbing motor spindle heat (Q) and a cooling unit (6) for cooling the cooling medium

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 2

The cooling medium is guided through a closed cooling circuit, whereby the cooling can also cool other areas of the spindle... The heat dissipated from the motor spindle by means of the cooling medium is cooled with a cooling unit

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

the cooling unit comprises at least one cooler (7) with surface-enlarging cooling structures

Methodology Applied
Scientific EffectHeat dissipation: Heat Sink

Implementation Method 4

ambient air is used here. By using a cooler, it is possible to dissipate heat in the rear area of the spindle unit to the ambient air... A fan (8) is additionally provided in order to generate an air flow for dissipating heat from the cooler

Methodology Applied
Scientific EffectForced convection: Forced Convection

Implementation Method 5

utilizing a cooling unit that can be specifically adapted to the motor spindle, including a cooler with surface-enlarging structures and optional fan-assisted air cooling, and a liquid cooling medium with phase transition for enhanced heat transfer

Methodology Applied
Scientific EffectPhase transition: Phase Change

Data Source

PatentEP1880798B1Spindle unit for fitting in a machine tool
Publication Date: 2009.02.25 FRANZ KESSLER GMBH
  • EP1880798B1 patent drawingFigure 1
  • EP1880798B1 patent drawingFigure 2

AI summary

The spindle unit (1) has a motor spindle (2) and a closed cooling circuit with a cooling agent provided for cooling the motor spindle. A cooling circuit is provided between a spindle housing (3) of the motor spindle for absorbing the heat of the motor spindle and a cooling unit (6) for cooling the cooling medium consists of cooling lines (4, 5) for transporting the cooling medium. The cooling unit is partially inserted in the spindle holder of a machine tool.