Fluid Pump Purge Passage and Filter for Wear Reduction
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Solution Overview
Problem
Existing fluid pumps, such as fuel pumps, suffer from contamination infiltration into axial clearances between the pumping element and plates due to pressure gradients, leading to abrasion and reduced flow output over time.
Innovation Solution
Incorporating a purge passage and filter downstream of the outlet plate passage to ensure clean fuel reaches the sealing interfaces, minimizing contamination and wear by maintaining consistent pressure and filtering out harmful contaminants.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a pre-filter or strainer is used to strain contaminants from fuel, then large debris is removed, but the filter cannot be fine enough without causing cavitation at the inlet
Solution Approach 1:
The filtration function is segmented into two stages: a pre-filter/strainer at the inlet for coarse filtration, and a second filter at the outlet for fine filtration. This segmentation allows each filter to be optimized for its specific function without compromising overall system performance.
Solution Approach 2:
The outlet filter performs preliminary cleaning of the fuel before it recirculates back to the pumping element sealing surfaces. This preliminary action prevents contaminants from infiltrating the axial clearances, addressing the contamination problem before it causes wear.
2Loss of energy
If axial clearances are made small to prevent high pressure fuel leakage, then leakage is reduced, but contaminants can more easily infiltrate and cause abrasion
Solution Approach 1:
The outlet filter acts as an intermediary between the high-pressure fuel and the pumping element sealing surfaces. It intercepts and removes contaminants before they can infiltrate the axial clearances, protecting the sealing surfaces from abrasion while allowing small clearances to maintain.
Solution Approach 2:
The high-pressure fuel that could potentially cause contamination infiltration is converted into a beneficial force by using it to drive the pumping element, while the outlet filter simultaneously removes contaminants from this pressurized fuel, turning a potential harm into a benefit.
3Object-affected harmful factors
If the pre-filter is made finer to strain out all harmful contaminants, then contamination is reduced, but flow restriction increases causing cavitation
Solution Approach 1:
The filtration system is segmented into coarse pre-filtration at the inlet and fine filtration at the outlet. This allows the pre-filter to maintain larger openings that prevent cavitation, while the outlet filter handles the fine filtration without impacting inlet pressure.
Solution Approach 2:
The filtration function is moved from the inlet dimension to the outlet dimension. By placing a filter at the outlet, the system achieves fine filtration without restricting inlet flow, as the outlet filter operates in a different flow dimension where pressure restrictions do not cause cavitation.
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 contamination and wear, extending the service life of the fluid pump by maintaining clean fuel interfaces and preventing abrasion, thereby enhancing the pump's efficiency and longevity.
Implementation Method 1
a filter downstream of the outlet plate outlet passage which filters fluid that passes through the purge passage prior to reaching the inlet sealing surface interface and the outlet sealing surface interface
Implementation Method 2
Infiltration of contaminants into the axial clearances is promoted by pressure gradients which exist between the inlet and radially inner and radially outer portions of the pumping element and by pressure gradients which exist between the outlet and radially inner and radially outer portions of the pumping element
Data Source
AI summary
A fluid pump includes an inlet plate with an inlet; an outlet plate, the outlet plate having an outlet plate outlet passage; an outlet; an electric motor having a shaft which rotates; a pumping element coupled to the shaft such that rotation of the pumping element by the shaft causes fluid to be pumped from the inlet to the outlet, the inlet plate interfacing with the pumping element in an inlet sealing surface interface and the outlet plate interfacing with the pumping element in an outlet sealing surface interface; a purge passage which receives fluid from the outlet plate outlet passage, the purge passage being in fluid communication with the inlet sealing surface interface and the outlet sealing surface interface; and a filter downstream of the outlet plate outlet passage which filters fluid that passes through the purge passage prior to reaching the inlet and outlet sealing surface interfaces.