Mechanical Seal With Pumping Areas And High-Lubricity Dam
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Solution Overview
Problem
Existing mechanical seals face challenges in maintaining seal integrity by balancing seal tightness and lubrication, particularly during initial rotation and when stopped, with existing solutions experiencing leakage and wear issues due to insufficient lubricity at the seal dam area.
Innovation Solution
The mechanical seal design incorporates circumferentially separated sealed-fluid-accommodating blocks with pumping areas on either the stationary or rotating rings, featuring a high-lubricity seal dam area formed from materials like PTFE, MOS2, WS2, graphite, or lubricative oil, ensuring solid contact and effective fluid management to prevent leakage and reduce wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the seal dam area is made to function as a seal barrier, then leakage prevention is improved, but wear occurs due to insufficient lubricity
Solution Approach 1:
The seal dam area is differentiated from the sealed fluid side by omitting the grating portions in this region. This creates a smooth, continuous sealing surface that maintains seal tightness while reducing friction and wear. The local quality change allows the seal dam area to function effectively as a barrier while having extended service life due to reduced wear.
2Object-affected harmful factors
If fluid lubrication state is reached to reduce friction, then mechanical damage is reduced, but fluid flows from positive pressure area causing leakage
Solution Approach 1:
The sealing face is segmented into distinct functional areas: the sealed fluid side with grating portions for fluid lubrication and friction reduction, and the seal dam area without grating portions to maintain seal tightness. This segmentation allows the system to achieve fluid lubrication for reducing mechanical damage while preventing fluid leakage through the strategically positioned seal dam area.
Solution Approach 2:
Different surface qualities are applied to different regions: the sealed fluid side has inclined indentations that generate dynamic pressure for lubrication, while the seal dam area has a smooth surface that prevents fluid escape. This local quality differentiation resolves the contradiction between reducing friction through fluid lubrication and preventing fluid leakage.
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 design maintains seal integrity by preventing leakage when stopped and reducing sliding torque and wear, allowing for extended operation with improved lubricity and fluid management, ensuring reliable seal functionality over time.
Implementation Method 1
Friction can be reduced by reaching a 'fluid lubrication state' in which dynamic pressure is generated between sealing faces due to rotation, and the surfaces slide with a liquid membrane interposed therebetween
Implementation Method 2
dynamic pressure is generated between sealing faces due to rotation
Implementation Method 3
a seal dam area on the sealing face on which said sealed-fluid-accommodating blocks are formed is formed from a high-lubricity sliding material
Implementation Method 4
Friction can be reduced by reaching a 'fluid lubrication state'
Data Source
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AI summary
{Problem} To provide sliding parts that do not leak when stopped, operate under fluid lubrication and prevent leakage when rotating, including during initial rotation, and are capable of achieving a balance between seal tightness and lubrication. {Solution} A plurality of circumferentially separated sealed-fluid-accommodating blocks are formed on the sealing face of either the stationary ring or the rotating ring so as to communicate with a sealed-fluid-accommodating space; pumping areas for generating a pumping action due to the stationary and rotating ring sliding in relative rotation are formed on the bottom of the plurality of sealed-fluid-accommodating blocks; the pumping areas formed on the bottom of the plurality of sealed-fluid-accommodating blocks are provided with intake pumping areas operating in a direction so as to draw in the sealed fluid and outflow pumping areas operating in a direction so as to expel the sealed fluid; and a seal dam area on the sealing face on which said sealed-fluid-accommodating blocks are formed is formed from a high-lubricity sliding material, the seal dam area being on the opposite side of the sealing face relative to the sealed-fluid side.