Sealless Over-Center Linkage for Diaphragm Pump
Solution Overview
Problem
Compressed air driven double diaphragm pumps face issues due to manufacturing tolerances causing excessive friction in seals, leading to unwanted positioning during operation, which requires manual intervention and downtime for resetting.
Innovation Solution
A novel changeover mechanism using a shaft with axial movement, a valve plate with multiple ports, and a pivotably mounted arm with resilient biasing means to ensure reliable switching between diaphragm chamber pressurization and exhaustion, allowing for easy maintenance and repair without disassembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If poppet valves are used with seals in the prior art design, then the pump can operate with a simple structure, but manufacturing tolerances cause excessive friction leading to unwanted positioning and pump failure
Solution Approach 1:
The invention extracts and removes the problematic seal component from the valve assembly. The new design uses sealless poppet valves where the valve stem passes through the diaphragm chamber wall without requiring seals, thereby eliminating the friction and reliability issues caused by seal-diafram interactions while maintaining the basic valve functionality.
Solution Approach 2:
Instead of sealing the valve stem against the diaphragm chamber wall (which causes friction), the invention inverts the approach by having the valve stem pass through the wall without contact. The sealing function is achieved differently, eliminating the need for traditional seals and their associated friction problems.
2Ease of operation
If manual resetting is required due to unwanted valve positioning, then the pump stops operating, but this requires manual intervention and causes downtime
Solution Approach 1:
The new valve design is self-service in that it eliminates the conditions that cause malfunction (excessive friction from seals). The sealless construction prevents the valve from sticking or positioning incorrectly, allowing the pump to operate continuously without requiring manual intervention or resetting, thereby eliminating downtime.
3Reliability
If the changeover mechanism is made more reliable with resilient biasing means, then the valve maintains continuous contact with the valve plate, but the device complexity increases
Solution Approach 1:
The invention introduces dynamic elements (resilient biasing means) to the valve mechanism, allowing the valve closure component to maintain continuous contact with the valve plate through spring pressure. This dynamic adjustment ensures reliable sealing and operation while the modular design keeps the overall complexity manageable.
Solution Approach 2:
The resilient biasing means is pre-configured to apply continuous pressure to the valve closure component, ensuring it remains in contact with the valve plate before any operation occurs. This preliminary action prevents potential malfunction by maintaining proper valve contact throughout operation without requiring complex control systems.
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 provides a more reliable and efficient pump operation with reduced downtime, enabling easy retrofits and maintaining manufacturing and operational costs, while ensuring continuous operation without manual intervention.
Implementation Method 1
resilient biasing means associated with the hinged link for biasing the position of the valve closure component to off centre of the valve plate
Implementation Method 2
a hinge received in the slots and connecting with a pair of linear tension springs which in turn are secured to the frame adjacent its pivot point
Implementation Method 3
means for driving the shaft to move axially in forward and reverse directions
Implementation Method 4
an arm pivotably mounted with respect to the valve and engaging with the shaft
Implementation Method 5
a changeover mechanism configured alternately to pressurise and exhaust the two diaphragm chambers
Data Source
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AI summary
A novel changeover mechanism for a compressed air driven double diaphragm pump comprises a shaft (21) slidably mounted through aligned apertures (22) in opposing surfaces of the twin diaphragm chambers (23). At the centre of the shaft (21) between the two diaphragm chambers (23) is provided an annular notch (24) in to which is located an arm (25) extending from a U shaped frame (26). The U shaped frame (26) is pivotally mounted atop a valve plate (27) which includes multiple ports (28). Positioned against a surface of the valve plate (27) is a valve closure component (29) which is configured to slide across the surface selectively obstructing the multiple ports (28). The valve closure component (29) is held in place by a metal peg (30) hingedly mounted in slots (31) provided in parallel extension of the U shaped frame (26). Linear tension springs (32) connect the hinged wire pusher (30) with U shaped frame (26) adjacent the pivot point. The springs (32) bias the position of the valve closure component (29) against the valve plate (27) in an off centre position.