Vacuum Pump Side Cover Thermal Insulation Design

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Solution Overview

Problem

In vacuum pump apparatuses used in semiconductor manufacturing, the heat from the pump casing can transfer to the motor and gear housings, causing a decrease in temperature within the rotor chamber, which can lead to the solidification of by-products and subsequent pump failure.

Innovation Solution

The vacuum pump apparatus incorporates a side cover with an integrally-formed structure that includes a narrow portion with a smaller cross-sectional area, reducing heat transfer from the pump casing to the motor and gear housings. Additionally, a heater is arranged within the side cover to maintain a high temperature within the rotor chamber.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a heater is provided on the pump casing to heat the rotor chamber, then the temperature in the rotor chamber is maintained to prevent solidification of by-products, but heat is transferred to the motor housing and gear housing causing temperature drop in the rotor chamber

Engineering Contradiction:
Improvetemperature in rotor chamberVSAvoidheat transfer to motor housing and gear housing
Core Design Contradiction:
TemperatureVSLoss of energy

Solution Approach 1:

The side cover is divided into three distinct portions (inner wall portion, narrow portion, outer wall portion) with different cross-sectional areas. The narrow portion specifically has a smaller cross-sectional area to reduce heat transfer, while the inner wall portion maintains heating function. This segmentation allows different regions to serve different thermal functions simultaneously.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different portions of the side cover are designed with different thermal properties. The narrow portion acts as a thermal barrier with reduced heat conduction, while the inner wall portion receives heater contact for localized heating. This local differentiation of thermal characteristics resolves the contradiction between maintaining temperature and preventing heat loss.

Inventive Principle:
Principle #3Local quality

2Reliability

If a high-power heater is used to maintain temperature in the rotor chamber, then solidification of by-products is prevented, but more electric power is consumed and energy-saving operation cannot be achieved

Engineering Contradiction:
Improveprevention of by-product solidificationVSAvoidelectric power consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The narrow portion, which would normally be considered a structural constraint, is converted into a beneficial thermal barrier. By designing this narrow portion with smaller cross-sectional area, the patent transforms potential heat loss into a useful insulation effect, reducing the energy required for heating while maintaining reliability.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The cross-sectional area parameter of the side cover is changed in the narrow portion to optimize thermal performance. This parameter modification reduces heat transfer coefficient, thereby lowering the power requirement for the heater while maintaining the necessary temperature in the rotor chamber for reliable operation.

Inventive Principle:
Principle #35Parameter changes

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 effectively maintains a high temperature within the rotor chamber, preventing the solidification of by-products and ensuring stable operation of the vacuum pump apparatus while also preventing overheating of the bearings.

Implementation Method 1

a heater is provided on an outer surface of the pump casing to heat the rotor chamber

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

a narrow portion with a smaller cross-sectional area, reducing heat transfer from the pump casing to the motor and gear housings

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP4067658B1Vacuum pump apparatus
Publication Date: 2025.02.12 EBARA CORP
  • EP4067658B1 patent drawingFigure 1
  • EP4067658B1 patent drawingFigure 2
  • EP4067658B1 patent drawingFigure 3

AI summary

A vacuum pump apparatus capable of preventing a decrease in temperature of a pump casing due to heat transfer, and capable of maintaining a high temperature in a rotor chamber is disclosed. A side cover is provided between a pump casing and a motor housing. The side cover includes an inner wall portion forming an end surface of the rotor chamber, an outer wall portion located outwardly of the inner wall portion, and a narrow portion located between the inner wall portion and the outer wall portion. The inner wall portion, the outer wall portion, and the narrow portion are an integrally-formed structure, and the narrow portion has a cross-sectional area smaller than cross-sectional areas of the inner wall portion and the outer wall portion.