Mechanical Seal Sliding Surfaces for Bidirectional Lubricity

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Solution Overview

Problem

Existing mechanical seals fail to maintain lubricity between sliding surfaces during reverse rotation, as positive pressure generation is not effective in dynamic pressure generating grooves when the rotation direction is reversed.

Innovation Solution

The design includes a pair of sliding surfaces with first and second dynamic pressure generating grooves extending in opposite circumferential directions, a conduit groove, and communication grooves to supply fluid to the gap between the sliding surfaces regardless of rotation direction, ensuring consistent lubricity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If dynamic pressure generating grooves are provided in the sliding surface, then lubricity is improved during forward rotation, but lubricity cannot be maintained during reverse rotation

Engineering Contradiction:

ImprovelubricityVSAvoidadaptability to rotation direction

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The sliding surface is segmented into multiple functional zones: first dynamic pressure generating grooves for forward rotation, second dynamic pressure generating grooves for reverse rotation, and conduit grooves that connect them. This segmentation allows each groove system to independently generate positive pressure for its designated rotation direction, resolving the contradiction by providing direction-specific lubrication pathways.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The conduit grooves serve multiple functions: they connect the first and second dynamic pressure generating grooves, allow fluid communication between opposite sides of the sliding surface, and enable the system to adapt to both forward and reverse rotation directions. This multi-functionality allows a single groove structure to serve universal lubrication purposes regardless of rotation direction.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If the sliding surfaces are separated by positive pressure, then smooth sliding is achieved, but the structure becomes complex to accommodate bidirectional rotation

Engineering Contradiction:

Improvesmooth slidingVSAvoidgroove structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The first dynamic pressure generating grooves, second dynamic pressure generating grooves, and conduit grooves are merged into a single integrated groove system on the sliding surface. This unified structure achieves smooth sliding in both rotation directions without requiring separate, independent groove systems, thereby reducing overall structural complexity while maintaining the positive pressure separation function.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

Instead of creating separate groove systems for each rotation direction, the invention uses conduit grooves to invert the fluid flow path, allowing the same groove structure to serve both forward and reverse rotation directions by redirecting fluid through the conduit pathways. This inversion approach simplifies the overall structure compared to having completely separate groove systems.

Inventive Principle:

Principle #13The other way round (Inversion)

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 ensures smooth sliding and reduced leakage by maintaining positive pressure generation and fluid supply between sliding surfaces, regardless of the relative rotation direction.

Implementation Method 1

During relative rotation between the sliding rings, since the sealed fluid concentrates from the space on the sealed fluid side toward closed end portions of the dynamic pressure generating grooves, and a positive pressure is generated

Methodology Applied

Scientific EffectDynamic pressure generation: Pressure Gradient

Implementation Method 2

the sliding surfaces are separated from each other, and a fluid film of the sealed fluid is formed between the sliding surfaces, so that lubricity can be improved

Methodology Applied

Scientific EffectFluid film lubrication: Lubrication

Data Source

PatentUS12473946B2Sliding components

Publication Date: 2025.11.18 EAGLE INDS

AI summary

There are provided sliding components that allow sliding surfaces to smoothly slide against each other regardless of whether a relative rotation direction is a forward rotation or a reverse rotation. The sliding components and include: a pair of sliding surfaces and disposed to face each other at a location where a relative rotation takes place when a rotating machine is driven. The sliding surface is provided with a first dynamic pressure generating groove communicating with a radially outer-side space and extending in one circumferential direction, a second dynamic pressure generating groove extending in the opposed circumferential direction, and a conduit groove communicating with the space. The conduit groove includes an annular groove and a communication groove communicating between the annular groove and the space. The second dynamic pressure generating groove is disposed closer to the space than the annular groove, and communicates with the annular groove.