Vacuum Pump Temperature Control for Sensor Failure Protection
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Solution Overview
Problem
Existing vacuum pumps, particularly turbomolecular pumps, face issues with overheating and overcooling due to abnormalities in temperature sensors controlling heaters or water-cooling solenoid valves, leading to deposition of process gases and reduced performance, with conventional temperature management systems failing to detect these abnormalities effectively.
Innovation Solution
A vacuum pump system with a temperature control mechanism that includes a timer to monitor temperature changes between upper and lower limits, forcibly changing the heating or cooling state if the temperature remains constant beyond a specified time, thereby detecting and preventing overheating or overcooling without additional sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the temperature of the base portion is increased to prevent product accumulation, then the pump performance is improved, but the electronic circuit may exceed the limit temperature and be destroyed
Solution Approach 1:
The patent divides the temperature control into two independent systems: one for the base portion (heating to prevent deposits) and one for the electronic circuit (cooling to prevent overheating). This segmentation allows each component to be controlled at its optimal temperature independently, resolving the contradiction between preventing product accumulation and protecting the electronic circuit.
2Temperature
If a temperature sensor is used to control the heater or water-cooling solenoid valve, then the temperature can be maintained, but the sensor may become abnormal and cause overheating or overcooling
Solution Approach 1:
The patent implements a feedback mechanism where the microcontroller continuously monitors the temperature sensor output and adjusts the heater and water-cooling solenoid valve accordingly. Additionally, the system monitors the operational state of these components and can detect sensor abnormalities through the lack of expected temperature changes, providing redundant feedback to ensure reliable control.
Solution Approach 2:
The system uses the existing temperature sensor and control components to monitor their own operational status. By observing whether the temperature changes as expected when the heater or cooling valve is activated, the system can self-diagnose sensor abnormalities without requiring additional external monitoring equipment.
3Measurement precision
If additional temperature sensors are added to detect sensor abnormalities, then the detection accuracy is improved, but the device complexity increases
Solution Approach 1:
The system uses the existing temperature sensor and control components to monitor their own operational status. By observing whether the temperature changes as expected when the heater or cooling valve is activated, the system can self-diagnose sensor abnormalities without requiring additional external monitoring equipment.
Solution Approach 2:
The microcontroller acts as an intermediary that indirectly monitors sensor health by analyzing the relationship between control commands (heater on/off, cooling valve open/close) and the resulting temperature readings. This intermediary approach detects abnormalities through software logic rather than additional physical sensors.
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
Ensures safe operation of the vacuum pump by preventing overheating or overcooling, detecting abnormalities through software processing, and maintaining consistent performance by alternating heating and cooling states when the temperature sensor fails to change within specified time limits.
Implementation Method 1
a heater or an annular water cooling pipe is wrapped around an outer circumference of a base portion or the like of the turbomolecular pump... wherein the base portion is heated by the heater
Implementation Method 2
the base portion is cooled by the water cooling pipe when the temperature of the base portion exceeds a predetermined temperature
Implementation Method 3
a temperature sensor is embedded in the base portion or the like... a temperature sensor that measures a temperature of a pump
Data Source
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AI summary
The present invention provides a vacuum pump and a temperature control device that are capable of preventing, with a simple configuration, overheating and overcooling of a pump that are caused due to abnormality in a temperature sensor used to control a heater or a water-cooling solenoid valve that is provided to prevent the deposition of products. Problems such as overheating and overcooling of a heater can be avoided in a case where a temperature sensor system fails and consequently the measured temperature continues to be constant between the upper limit and the lower limit. TMS function controls the measured temperature of the temperature sensor to a target temperature. Thus, if an application such as a target to be heated or a heater capacity is identified, the same cycles of turning ON/OFF of the heater or the water-cooling solenoid valve are repeated, and the upper limit of the time in which the ON/OFF state is sustained continuously is determined. An allowed time considering a margin is provided for this upper limit, and the ON/OFF state is changed so that the ON state or the OFF state is not continuously sustained beyond the allowed time.