Vacuum Pump Check Valve Pneumatic Actuation
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Solution Overview
Problem
Vacuum pumps, such as rotary vane pumps, experience a decrease in delivery capacity at low pressures (less than 1 mbar) due to the inefficiency of existing non-return valves, which require either an oil pump or an electromagnetic valve to maintain sealing, both of which have drawbacks.
Innovation Solution
A fluid device actuates a check valve to ensure it remains fully open at low pressures, eliminating the need for an electromagnetic valve by using a fluidically actuated switching element and pressurized fluid to maintain the valve's closed position during operation and open it when the pump is switched off.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a spring-set check valve is used to prevent medium flowback, then the valve closes reliably when the pump is switched off, but the valve must be positioned close to the sealing surface which reduces delivery capacity at low pressures
Solution Approach 1:
The patent applies pneumatic principles by using a fluid device (pneumatic actuator) to replace the mechanical spring mechanism. The fluid device uses pressurized fluid to actuate the check valve, allowing it to remain fully open during operation and close reliably when the pump stops, eliminating the need to position the valve close to the sealing surface and thereby maintaining high delivery capacity at low pressures while ensuring reliable closure.
2Productivity
If an electromagnetic valve is used to maintain check valve sealing at low pressures, then pump performance is maintained, but additional control devices and power supply are required
Solution Approach 1:
The patent replaces the electromagnetic valve with a fluid device (pneumatic actuator) that uses pressurized fluid from the pump's own outlet to control the check valve. This eliminates the need for external power supply and complex electrical control systems, reducing device complexity while maintaining pump performance at low pressures through pneumatic actuation.
3Reliability
If an oil pump is used to maintain check valve closure, then the check valve remains sealed, but the system requires additional components and ongoing oil pressure maintenance
Solution Approach 1:
The patent implements a self-service system where the fluid device uses pressurized fluid from the pump's own outlet to actuate the check valve. The system utilizes the pump's own operating pressure to close the check valve when the pump stops, eliminating the need for a separate oil pump and ongoing pressure maintenance, thereby reducing device complexity while maintaining reliable sealing.
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 maintains high pump capacity at low pressures without requiring an electromagnetic valve, using fluid pressure to ensure reliable closure and rapid opening of the check valve, thus enhancing pumping efficiency.
Implementation Method 1
a fluid device (36) is provided which, when the vacuum pump is switched off, acts on the check valve (28) to close it
Data Source
Figure 1~2
Figure 3
AI summary
The invention relates to a vacuum pump, particularly a rotary vane pump, having a pump housing (10) which is arranged in a suction chamber (12). A conveying element (14, 16) is arranged in the suction chamber (12). According to the invention, there is a non-return valve (28) at an inlet (22) of the suction chamber (12). To close the non-return valve (28) in the case of prevailing low pressures in the region of the inlet (22), a fluid device (36) is arranged adjacent to a spiral spring (34). Upon deactivation of the vacuum pump, a switch piston (40) is moved to a position in which fluid flows through the feed channel (42) into the connection channel (38), so that the non-return valve (28) closes via the flowing into the inlet channel (42).