Gear Pump Weepage Control via Drain Bushing and Arbor Opening
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Solution Overview
Problem
Gear pumps used in polymer applications face issues with incomplete removal and leakage of degraded polymer material, requiring frequent mechanical cleaning and posing environmental risks.
Innovation Solution
A drainage arrangement featuring a drain bushing and lip seal replaces traditional packing seals, directing degraded media through radial holes and longitudinal openings in the arbor to dedicated ports for continuous collection, eliminating recirculation paths and using a hollow driven shaft to direct flow from the front to the rear bearing, ensuring complete containment and isolation from the environment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a packing seal is used to throttle the flow rate through the bearing, then weepage of media past the shaft bearing is controlled, but degraded polymer builds up on pump surfaces requiring periodic mechanical removal
Solution Approach 1:
The patent extracts the degraded polymer from the pump interior by providing dedicated drainage ports that lead to external collection containers. The longitudinal opening in the arbor and radial holes in the drain bushing create extraction paths that remove degraded material before it can accumulate on pump surfaces, eliminating the need for periodic mechanical cleaning while maintaining reliable weepage control.
Solution Approach 2:
The patent introduces intermediary components (drain bushing with radial holes, longitudinal opening in arbor, drainage ports in rear plate) that mediate between the bearing area and the external environment. These intermediaries provide controlled pathways for degraded polymer to exit the pump system, allowing weepage control to be maintained without direct accumulation on pump surfaces.
2Productivity
If degraded material is vented through end plates to a lower pressure region, then material is removed from the pump, but incomplete removal and environmental leakage occur
Solution Approach 1:
The patent provides dedicated extraction paths through radial holes in the drain bushing and longitudinal openings in the arbor that completely remove degraded polymer from the pump system. The drainage ports in the rear plate lead directly to external collection containers, ensuring complete removal rather than partial venting, and preventing environmental leakage by containing all evacuated material in closed containers.
Solution Approach 2:
The patent uses simple, easily replaceable drainage components (drain bushing, arbor with longitudinal opening) that provide reliable degradation material removal. The system allows for complete evacuation of degraded material through dedicated ports that can be connected to collection systems, ensuring no harmful factors are released to the environment.
3Productivity
If positive pumping spiral grooves are provided on a drive shaft extension, then degraded material is pumped away from bearings, but material still leaks to the environment
Solution Approach 1:
The patent extracts degraded material through dedicated drainage ports that lead to external collection containers. The longitudinal opening in the arbor and radial holes in the drain bushing create complete extraction paths, removing degraded polymer from the system rather than merely pumping it away, thereby preventing environmental release entirely.
Solution Approach 2:
The patent introduces intermediary drainage components (drain bushing, longitudinal opening, drainage ports) that mediate between the bearing area and the external environment. These intermediaries provide controlled, contained pathways for degraded polymer evacuation, preventing direct environmental release while maintaining efficient material removal.
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 enables continuous removal and collection of degraded polymer, reducing maintenance needs and environmental leakage, extending the service life of the drive shaft by eliminating the need for periodic cleaning and ensuring all evacuated material is handled within an onsite system.
Implementation Method 1
pumped media that passes between the first bearing and an outer surface of the arbor in a first direction is directed to the second drain port via the longitudinal opening in a second direction different from the first direction
Data Source
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AI summary
A pump includes a front plate, a gear plate and a rear plate. A drive shaft has a drive gear, an arbor has a driven gear engaged with the drive gear, and first and second bearings are disposed in the gear plate. The first and second bearings receive the drive shaft and the arbor. The rear plate has drain ports adjacent ends of the drive shaft and the arbor. The arbor has an opening such that media that passes between the first bearing and an outer surface of the arbor is directed to the second drain port via the opening. A drain bushing is positioned against the front plate, and includes an opening for the drive shaft. The drain bushing has a chamber and a radial port. When pumped media passes between the first bearing and the drive shaft it is directed to the chamber and out the radial port.