Vacuum Pump Stator Thermal Coupling for Reaction Product Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional turbo-molecular pumps face issues with reaction product accumulation on the inner and outer screw stators due to temperature increases during gas discharge, leading to reduced rotor diameter and pump restart troubles, as well as potential stoppages from rapid reaction product accumulation.
Innovation Solution
The vacuum pump design thermally couples the inner and outer screw stators, with the outer stator being thermally insulated from the base, allowing heat transfer to maintain the inner stator above the sublimation temperature of reaction products, preventing accumulation and ensuring pump reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the motor stator is cooled by driving the cooling jacket to discharge a large amount of gas, then the motor stator temperature is reduced, but reaction products rapidly increase and accumulate in the gap between the rotor cylindrical section and the inner screw stator
Solution Approach 1:
A heating device is introduced as an intermediary component to heat the inner screw stator and maintain its temperature above the sublimation point of reaction products. This heating device acts as a mediator between the cooling system and the reaction products, preventing accumulation by controlling the temperature condition without directly interacting with the gas flow or reaction process.
Solution Approach 2:
The temperature parameter of the inner screw stator is actively controlled and maintained above the sublimation point of reaction products. By changing and controlling this critical temperature parameter, the system prevents reaction product accumulation while allowing efficient gas discharge through the cooling jacket.
2Reliability
If the inner screw stator is cooled during pump operation, then condensation of reaction products occurs on the inner screw stator, but the rotor cylindrical section adheres to the reaction products causing pump restart troubles
Solution Approach 1:
The heating device performs preliminary action by maintaining the inner screw stator temperature above the sublimation point of reaction products before and during pump operation. This preventive heating action stops reaction products from condensing and accumulating, thereby preventing adhesion issues that would阻碍 pump restart.
Solution Approach 2:
The system converts the potentially harmful cooling effect that causes reaction product condensation into a beneficial controlled temperature maintenance. By using the heating device to counteract excessive cooling, the system transforms the harmful condensation effect into a beneficial temperature control mechanism that prevents adhesion while allowing efficient operation.
3Productivity
If both inner and outer screw stators are cooled to improve gas discharge performance, then exhaust performance improves, but reaction product accumulation increases and causes pump stoppages
Solution Approach 1:
Different temperature control strategies are applied to different parts of the system: the outer screw stator is cooled to improve gas discharge performance, while the inner screw stator is heated to prevent reaction product accumulation. This local differentiation of thermal conditions allows simultaneous optimization of exhaust performance and operational reliability.
Solution Approach 2:
The temperature parameters of the inner and outer screw stators are independently controlled and maintained at different values. The inner screw stator temperature is maintained above the sublimation point to prevent accumulation, while the outer screw stator is cooled for efficient gas discharge, achieving both high productivity and reliability through parameter optimization.
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 suppresses reaction product accumulation, prevents pump stoppages, and maintains the inner stator temperature above the sublimation point, ensuring consistent operation and reducing backflow-induced product accumulation.
Implementation Method 1
an outer stator forming an outer gas discharge path of the screw groove exhaust section between an outer peripheral surface of the rotor cylindrical section and the outer stator, and being thermally coupled to the inner stator
Implementation Method 2
a base cooling device for cooling the base
Data Source
AI summary
A vacuum pump comprises a screw groove exhaust section including a rotor cylindrical section and a stator; a base; an inner stator forming an inner gas discharge path between an inner peripheral surface of the rotor cylindrical section and the inner stator; an outer stator forming an outer gas discharge path between an outer peripheral surface of the rotor cylindrical section and the outer stator, and being thermally coupled to the inner stator; a communication opening formed on the rotor, and allowing the outer gas discharge path and the inner gas discharge path to communicate with each other on an upstream side; an exhaust opening discharging the joined gas of the gas passing through the outer gas discharge path and the gas passing through the inner gas discharge path from the screw groove exhaust section toward the exhaust port.