Positive Displacement Pump Forward Seal Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rotary positive displacement pumps require extensive disassembly to service seals, leading to prolonged downtime and maintenance challenges, as the entire pump body must be detached from the gear case to access and clean the seals.
Innovation Solution
The introduction of a forwardly-positioned primary sealing arrangement that can be accessed and removed without disassembling the pump body from the gear case, along with a secondary rearwardly-positioned selective sealing arrangement that seals the internal cavity when the rotors and primary sealing arrangement are removed, allowing for cleaning without exposing the secondary sealing arrangement to the pumped fluid during normal operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of repair
If the entire pump body is detached from the gear case to service the seals, then the seals can be accessed and cleaned, but the pump experiences prolonged downtime and increased maintenance complexity
Solution Approach 1:
The sealing arrangement is divided into multiple segments: a first seal at the forward end accessible without disassembly, and a second seal at the rearward end accessible only after rotor removal. This segmentation allows selective servicing of different seal components based on maintenance needs, enabling the first seal to be serviced independently to reduce downtime while the second seal can be accessed when complete overhauls are performed.
Solution Approach 2:
The first sealing arrangement is extracted and positioned at the forward end of the pump body, separate from the main pump body-gear case interface. This extraction allows the first seal to be accessed and removed independently without detaching the entire pump body from the gear case, directly addressing the downtime issue by enabling quick seal replacement.
2Ease of repair
If the pump body is detached from the gear case to access seals, then seal maintenance is possible, but the overall device complexity increases due to additional disassembly steps
Solution Approach 1:
The sealing system is segmented into a first sealing arrangement accessible through the forward end and a second sealing arrangement at the rearward end. This segmentation creates independent access paths to different seal components, allowing maintenance personnel to service only the necessary seal without increasing overall device complexity - they can choose to access just the first seal for routine maintenance or proceed to the second seal for comprehensive service.
Solution Approach 2:
The first sealing arrangement is extracted from the traditional enclosed position between the pump body and gear case and repositioned at the forward end. This extraction creates a dedicated access point that simplifies the disassembly process for seal maintenance, as only the rotor needs to be removed rather than detaching the entire pump body, thereby reducing operational complexity.
3Reliability
If a secondary sealing arrangement is added to seal the cavity when rotors are removed, then cleaning can be performed without fluid leakage, but the device complexity increases
Solution Approach 1:
The second sealing arrangement serves multiple functions: it seals the cavity when rotors are present to maintain normal pumping operation, and it seals the cavity when rotors are removed to enable effective cleaning. This multi-functionality justifies the additional component by providing both operational sealing and cleaning sealing capabilities without requiring separate systems.
Solution Approach 2:
The second sealing arrangement is positioned and configured to automatically seal the cavity in response to rotor presence or absence, enabling the pump to maintain reliability during both operation and cleaning modes. The seal activates as needed based on the operational state, providing self-service functionality that enhances reliability without requiring complex external control systems.
Data Source
AI summary
A rotary positive displacement pump comprising a pair of forwardly-positioned sealing arrangements and a pair of rearwardly-positioned selective sealing arrangements. The forwardly-positioned sealing arrangements each form a dynamic seal between a central portion of the one of the rotors and a corresponding hub proximate the forward ends of the shafts on which the rotors are received. The rearwardly-positioned selective sealing arrangements are located between the gear case and the pump body proximate the rearward ends of the shafts. When the rotors are secured to the shafts, the rearwardly-positioned selective sealing arrangements do not establish seals between the gear case and the pump body. However, when the rotors are removed from the shafts, the rearwardly-positioned selective sealing arrangements establish seals between the gear case and the pump body.