Vacuum Pump Heat Insulating Spacer for Stator Thermal Control

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Solution Overview

Problem

In vacuum pumps used for semiconductor manufacturing, the heat transfer from the stator to the casing causes the stator to cool below the sublimation point of gases, leading to solidification and reduced compression performance due to direct contact and high thermal conductivity.

Innovation Solution

A heat insulating spacer with low thermal conductivity is interposed between the casing and stator, supporting the stator in both radial and axial directions, maintaining a gap to prevent heat escape and reduce thermal resistance, and featuring a configuration with radial and axial supporting portions to manage thermal expansion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the stator is directly supported by the casing in the rotor radial direction, then the structural stability is improved, but the heat escapes from the stator to the casing causing temperature to drop below sublimation point

Engineering Contradiction:
Improvestructural stabilityVSAvoidstator temperature
Core Design Contradiction:
Stability of the object's compositionVSTemperature

Solution Approach 1:

A heat insulating spacer is introduced as an intermediary component between the stator and the casing. This spacer supports the stator in the rotor radial direction while providing thermal insulation, preventing heat escape from the stator to the casing and maintaining stator temperature above the sublimation point of compressed gas.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The support structure is segmented into two distinct functional components: the heat insulating spacer that provides thermal insulation and the support means that provides mechanical support. This segmentation allows the spacer to maintain thermal isolation while the support means ensures structural stability.

Inventive Principle:
Principle #1Segmentation

2Strength

If the stator and casing are in direct contact, then the mechanical support is improved, but the thermal resistance decreases causing excessive heat loss

Engineering Contradiction:
Improvemechanical supportVSAvoidheat loss
Core Design Contradiction:
StrengthVSLoss of energy

Solution Approach 1:

The heat insulating spacer serves as a mediator that provides mechanical support functionality while simultaneously providing thermal insulation. The support means works in conjunction with the spacer to maintain the stator's position without creating direct thermal contact between the stator and casing.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Temperature

If heating means is used to maintain stator temperature, then the temperature control is improved, but the device complexity increases

Engineering Contradiction:
Improvestator temperature controlVSAvoiddevice complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

Instead of using active heating means, the heat insulating spacer acts as a passive intermediary that prevents heat escape. This passive insulation approach maintains stator temperature above the sublimation point without adding complex heating control systems.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 configuration maintains the stator temperature above the sublimation point of gases, preventing solidification and enhancing the vacuum pump's performance by minimizing heat loss and maintaining efficient gas compression.

Implementation Method 1

a heat insulating spacer that is interposed between the casing and the stator, supports the stator in a rotor radial direction, with keeping a gap between the casing and the stator

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

As the temperature of the stator 102 increases, the stator 102 becomes thermally expanded and enlarged in the direction of the arrow shown in FIG. 4

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP3106669B1Vacuum pump and heat insulating spacer used for said vacuum pump
Publication Date: 2020.04.29 EDWARDS JAPAN
  • EP3106669B1 patent drawingFigure 1
  • EP3106669B1 patent drawingFigure 2(a)~2(c)
  • EP3106669B1 patent drawingFigure 3(a)~3(b)

AI summary

Provided is a vacuum pump for preventing solidification of gas in a thread groove portion, and a heat insulating spacer used in the vacuum pump. The vacuum pump includes a heat insulating spacer that is interposed between a casing and an outer circumferential stator having a thread groove portion, supports the outer circumferential stator coaxially with a rotor in a rotor radial direction, with keeping a gap between the casing and the outer circumferential stator, and has lower thermal conductivity than the casing and the outer circumferential stator.