Vacuum Pump Heating Portion Prevents Adhesion and Flux Leaks

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Solution Overview

Problem

Conventional vacuum pumps face issues with product adhesion on the lower side of the casing, magnetic flux leaks leading to electric system malfunctions, and high costs due to the need for expensive vacuum connectors.

Innovation Solution

The vacuum pump design includes a heating portion with a heater spacer, yoke, and heating plate, where the coil is used for electromagnetic induction heating to prevent adhesion and reduce magnetic flux leaks, and a seal means sets the pressure inside the recess to outside pressure to prevent vacuum electric discharge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the coil is disposed downstream of the thread groove pump stage in the low vacuum region, then electromagnetic induction heating can be applied to prevent adhesion, but insulating coating breakage occurs due to vacuum electric discharge and coil life is shortened

Engineering Contradiction:
Improveheating temperature of pump componentsVSAvoidcoil life and electric system stability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The pump is divided into two pressure regions: the heating portion (recess 21) is maintained at atmospheric pressure while the pump chamber is at vacuum pressure. This segmentation allows the coil to operate in a non-vacuum environment, preventing vacuum electric discharge and insulating coating breakage, while still achieving heating of pump components through the heating plate 23.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The heating plate 23 acts as an intermediary component that transfers thermal energy from the coil (located in atmospheric pressure region) to the pump components (in vacuum region). The heating plate conducts heat to the thread groove pump stage and other components, enabling indirect heating without exposing the coil to vacuum conditions.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If the connector is disposed inside the vacuum chamber and connected to the coil, then electromagnetic induction heating can be implemented, but expensive vacuum connectors are required and costs increase

Engineering Contradiction:
Improveability to implement electromagnetic induction heatingVSAvoidconnector cost and system complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The connector 100 is located in the atmospheric pressure region rather than the vacuum chamber, separating the electrical connection system from the vacuum environment. This allows the use of standard, inexpensive connectors instead of costly vacuum-compatible connectors, while the heating function is maintained through the heating plate 23 that transfers heat to the vacuum chamber components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The heating plate 23 serves as a mediator that enables thermal coupling between the coil (in atmospheric region) and the vacuum chamber components. This intermediary structure allows electrical components to remain outside the vacuum while still achieving the desired heating effect inside the vacuum chamber.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If the lower side of the casing is not heated, then the heating structure can be simplified, but product adhesion occurs on the lower side and overall adhesion amount increases

Engineering Contradiction:
Improveheating structure complexityVSAvoidproduct adhesion on casing
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The heating plate 23 performs multiple functions: it provides electromagnetic induction heating to prevent adhesion on the lower side of the casing, supports the thread groove pump stage, and acts as a thermal conductor to heat surrounding components. This multi-functionality achieves comprehensive adhesion prevention without requiring separate heating elements for each function.

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

Solution Approach 2:

The heating system changes the temperature parameter of the lower pump components from ambient/cold to heated conditions. By controlling the temperature of the heating plate 23 and associated components, the system prevents product adhesion through thermal effects while maintaining a relatively simple heating structure.

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 reduces product adhesion, prevents magnetic flux leaks, extends coil life, and allows the use of less expensive connectors, enabling stable long-term operation and cost reduction.

Implementation Method 1

electromagnetic induction heating by feeding an alternating current to the coil (26)

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

the heating plate (23) in contact with the thread-groove-exhaust-portion stators (18A, 18B)

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

a seal means (24) capable of setting the inside of the recess (21) to an outside pressure

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Data Source

PatentEP2952743B1Vacuum pump
Publication Date: 2022.05.11 EDWARDS JAPAN
  • EP2952743B1 patent drawingFigure 1
  • EP2952743B1 patent drawingFigure 2
  • EP2952743B1 patent drawingFigure 3

AI summary

An object is to reduce an adhesion amount of a product in a vacuum pump as a whole and effectively prevent occurrence of a trouble in a vacuum pump electric system due to a magnetic flux leak. A vacuum pump includes a rotor enclosed in a pump case, a rotating shaft fixed to the rotor, a supporting means that rotatably supports the rotating shaft, a driving means that rotates the rotating shaft, and thread-groove-exhaust-portion stators that form thread grove exhaust passages between the thread-groove-exhaust-portion stator and an outer circumferential side of or an inner circumferential side of the rotor. A heating portion is provided below the thread-groove-exhaust-portion stators. The heating portion includes a yoke, a coil, and a heating plate. The heating portion heats the yoke and the heating plate with electromagnetic induction heating by feeding an alternating current to the coil.