Scroll Pump Over-Compression Relief via Bypass Conduit
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Solution Overview
Problem
Existing scroll compressors experience over-compression during the initial roughing phase, leading to increased load and power requirements due to pressure generation above atmospheric levels when the inlet is at atmosphere, which is undesirable.
Innovation Solution
A vacuum pump with a scroll pumping mechanism featuring a gas conduit and a one-way valve arrangement that allows over-compression to be exhausted from a first location to a second location, with two one-way valves to prevent gas flow upstream and relieve pressure when a predetermined differential is reached, reducing the load on the pump and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the scroll pump operates during initial roughing with inlet at atmosphere, then gas compression is achieved, but over-compression occurs generating pressure above atmosphere which increases load and power requirement
Solution Approach 1:
The patent extracts the over-compression problem by providing a separate gas conduit that diverts excess compressed gas away from the main pumping channel. This allows the pump to maintain compression capability while releasing excess pressure through the bypass conduit, thereby reducing the load and power requirement during roughing operation.
Solution Approach 2:
The gas conduit acts as an intermediary element between the pumping channel and the discharge. It provides a controlled pathway for excess gas to escape, mediating between the compression function and the need to limit pressure buildup, thus reducing the energy required for compression.
2Use of energy by moving object
If a gas conduit is added to relieve over-compression, then power consumption is reduced, but device complexity increases
Solution Approach 1:
The gas conduit system is designed to operate automatically based on pressure differential. The one-way valve arrangement opens and closes based on the pressure difference between the pumping channel and the conduit, requiring no external control mechanism. This self-regulating feature minimizes control complexity while achieving power reduction.
Solution Approach 2:
The system uses pneumatic principles with one-way valve arrangements that respond to pressure differentials to control gas flow through the conduit. This passive pneumatic control mechanism avoids complex electronic or mechanical control systems, reducing overall device complexity while managing power consumption.
3Stress or pressure
If one-way valve arrangement is used to control gas flow, then over-compression is relieved, but pressure differential control becomes more complex
Solution Approach 1:
The one-way valve arrangement automatically responds to pressure differentials between the pumping channel and the gas conduit. When the pressure differential exceeds a certain threshold during roughing, the valves open to relieve over-compression; when the differential decreases, the valves close. This self-service operation eliminates the need for external control mechanisms.
Solution Approach 2:
The system utilizes changes in pressure differential as the controlling parameter for valve operation. The one-way valves are designed to open at a specific pressure differential threshold and close when the differential decreases, providing automatic pressure control based on physical parameter changes rather than complex control logic.
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
The solution effectively reduces the load on the pump and power consumption by releasing over-compression during the initial roughing phase, maintaining high pressure differentials while preventing contamination and ensuring efficient operation, achieving pressure differentials of up to 10,000:1 between the scroll inlet and outlet.
Implementation Method 1
a one-way valve arrangement located in the gas conduit for allowing the passage of gas through the conduit from the conduit inlet to the conduit outlet only when a predetermined pressure differential between the first and second locations of the pumping channel is generated
Implementation Method 2
the one-way valve arrangement comprises two one-way valves located in the gas conduit for resisting the passage of gas through the conduit from the conduit inlet to the conduit outlet when closed
Implementation Method 3
two scrolls which are co-operable for pumping gas along a pumping channel from an scroll inlet to a scroll outlet of the mechanism on relative orbiting motion of the scrolls
Data Source
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AI summary
The present invention relates to a scroll pump (10) which comprises two scrolls (20, 22) which are co-operable for pumping fluid from an inlet to an outlet on relative orbiting motion of the scrolls. Each scroll (20, 22) comprises a scroll base (30, 36) from which a scroll wall (28, 34) extends generally axially towards the base of the opposing scroll. A gas conduit (38) having an inlet (40) at a first location of the pumping channel (32) and an outlet (42) at a second location of the pumping channel allows over-compression at the first location of the pumping channel to be exhausted to the second location of the pumping channel. A one-way valve (44) located in the gas conduit (38) allows the passage of gas through the conduit from the conduit inlet (40) to the conduit outlet (42) only when a predetermined pressure differential between the first and second locations of the pumping channel is generated during roughing when the scroll inlet is at or close to atmosphere.