Turbo-Molecular Pump Stator Heating Control

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The existing turbo-molecular pumps face challenges with rotor and stator contact during start-up due to insufficient stator temperature elevation, leading to complex operation procedures and potential mechanical issues, especially when the stator is at normal temperature and the rotor is already hot.

Innovation Solution

A turbo-molecular pump system that includes a heater to elevate the stator temperature to a target temperature, a temperature sensor to monitor the stator temperature, and a control section that manages the rotor's rotation speed, stopping or reducing it until the stator reaches a predetermined temperature lower than the target, thereby preventing contact between the rotor and stator.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the stator temperature is elevated to prevent rotor-stator contact, then reliability is improved, but operation complexity increases due to required pre-heating procedures

Engineering Contradiction:

Improverotor-stator contact preventionVSAvoidpump start-up operation

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The control section automatically performs preliminary heating of the stator before rotor rotation begins. The heater is activated in advance to elevate the stator temperature to a predetermined level, ensuring thermal expansion occurs before the rotor starts rotating, thereby preventing contact between rotor and stator components.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses its own heating mechanism to automatically prepare the stator for rotor operation. The control section monitors temperature and manages the heating process internally, making the system self-sufficient in preventing rotor-stator contact without requiring external intervention or complex user procedures.

Inventive Principle:

Principle #25Self-service

2Reliability

If the stator dimensions are set for expanded state, then reliability is improved, but the gap dimension at normal temperature becomes smaller increasing contact probability

Engineering Contradiction:

Improvegap dimension optimizationVSAvoidrotor-stator contact risk

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system dynamically changes the temperature parameter of the stator from normal temperature to an elevated predetermined temperature before rotor operation. This parameter change causes thermal expansion of the stator, increasing the gap dimension to optimal levels and preventing harmful contact between rotor and stator components.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention explicitly utilizes thermal expansion of the stator by heating it to a predetermined temperature before rotor rotation. The control section activates the heater to elevate stator temperature, causing the stator to expand thermally and increase the gap dimension, thereby preventing rotor-stator contact during operation.

Inventive Principle:

Principle #37Thermal expansion

3Reliability

If temperature elevation is performed before start-up, then reliability is improved, but time consumption increases

Engineering Contradiction:

Improvetemperature control precisionVSAvoidstart-up time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The control section implements feedback control by continuously monitoring the stator temperature and comparing it to a predetermined target temperature. Based on this feedback, the control section adjusts the heater operation and rotor rotation timing, optimizing the balance between achieving reliable temperature elevation and minimizing start-up time consumption.

Inventive Principle:

Principle #23Feedback

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 solution allows for safe and efficient start-up of the pump by ensuring the stator is adequately heated before reaching the target rotation speed, reducing the risk of contact and simplifying the operation process, thus preventing mechanical issues and enhancing operational reliability.

Implementation Method 1

a heater configured to elevate a temperature of the stator to a target temperature

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Implementation Method 2

a temperature sensor configured to detect the temperature of the stator

Methodology Applied

Scientific EffectThermal detection: Thermocouple

Implementation Method 3

When the temperature of the stator is elevated, the stator thermally expands to change a gap dimension between a rotor and the stator

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS10590955B2Turbo-molecular pump

Publication Date: 2020.03.17 SHIMADZU CORP

AI summary

A turbo-molecular pump comprises a cylindrical rotor to be rotatably driven by a motor; a cylindrical stator provided corresponding to the rotor; a heater configured to elevate a temperature of the stator to a target temperature; a temperature sensor configured to detect the temperature of the stator; and a control section. A rotation start command is input after start of energization of the heater, the control section stops rotary driving of the rotor at a rated rotation speed until the temperature of the stator reaches a predetermined temperature set lower than the target temperature and begins the rotary driving at the rated rotation speed when the temperature of the stator exceeds the predetermined temperature.