Vacuum Pump Oil Backflow Prevention via Atmospheric Valve Extraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing oil-sealed rotary vacuum pumps face issues with lubricating oil backflow into the vacuum chamber when stopped, contaminating vacuum piping and vessels, and require complex control systems and additional space for shut-off and air introduction valves.
Innovation Solution
A pump design incorporating a non-return valve and air introduction valve that uses pressure differences to prevent lubricating oil backflow, eliminating the need for a vacuum-controlled control system and simplifying the configuration by interlocking the hydraulic pump with the pump body.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a shut-off valve and air introduction valve are added to prevent oil backflow, then oil backflow prevention is improved, but device complexity and space requirements increase
Solution Approach 1:
The invention extracts the valve control function from the vacuum environment and relocates it to the atmospheric environment. The non-return valve is positioned in the atmospheric side of the system, eliminating the need for vacuum-compatible valves and control systems. This separation allows standard atmospheric valves to be used, reducing complexity while maintaining oil backflow prevention.
Solution Approach 2:
The non-return valve acts as an intermediary element between the vacuum chamber and atmospheric environment. It selectively allows air passage during pumping operations while blocking oil backflow when the pump stops, thereby preventing contamination without requiring complex control mechanisms in the vacuum system.
2Reliability
If shut-off valves are installed to prevent oil backflow, then oil backflow prevention is improved, but installation space requirements increase
Solution Approach 1:
The control valves are extracted from the vacuum chamber installation space and relocated to the atmospheric side. The non-return valve is installed in the air supply line outside the vacuum environment, eliminating the need for dedicated valve space within the vacuum chamber and reducing overall installation footprint.
3Reliability
If a complex control system is used to manage valves under vacuum, then oil backflow prevention is improved, but manufacturing costs increase
Solution Approach 1:
The control system is extracted from the vacuum environment and relocated to atmospheric conditions. Standard atmospheric valves and control mechanisms can be used, which are less expensive to manufacture and install compared to vacuum-compatible components. This eliminates the need for costly vacuum-sealed valve assemblies and complex control wiring.
Solution Approach 2:
The invention uses simple, inexpensive non-return valve mechanisms that can be manufactured with basic materials. These valves operate passively using pressure differential, eliminating the need for expensive motorized actuators, sensors, and control electronics that would increase manufacturing costs.
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
Effectively prevents lubricating oil from flowing into the upstream side, reducing contamination and space requirements, and simplifies the control system, lowering development and production costs.
Implementation Method 1
a non-return valve which is disposed in a flow path between the inlet and the pump body to open and close the inlet; an air introduction path which introduces a gas having a higher pressure than a vacuum into the non-return valve
Implementation Method 2
a hydraulic pump which pressure-feeds a lubricating oil to the pump body in accordance with the driving of the pump body
Data Source
Figure 1
Figure 2
Figure 3(a)~3(c)
AI summary
A pump comprises: a pump body 10 which sucks in air from an inlet 7 and discharges the air; a hydraulic pump which pressure-feeds a lubricating oil to the pump body 10 in accordance with the driving of the pump body 10; a non-return valve 70 which is disposed in a valve accommodation portion 6 between the inlet 7 and the pump body 10 to open and close the valve accommodation portion 6; an air introduction path 19 which introduces air into a cylinder 74 of the non-return valve 70; and an air introduction valve 60 which opens the air introduction path 19 when the hydraulic pump is not operating. When the pump body 10 is stopped, the non-return valve 70 closes the inlet 7 in response to a difference in pressure between the pressure of the valve accommodation portion 6 reduced to a value equal to or less than atmospheric pressure by the operation of the pump body 10, and the pressure of the air introduced into the cylinder 74 by the opening of the air introduction valve 60 owing to the stoppage of the hydraulic pump associated with the stoppage of the pump body 10.