Pumping Ring Geometry for Mechanical Seal Cooling Flow

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Solution Overview

Problem

Existing mechanical seals in rotary shaft equipment face issues with frictional wear leading to gaps and leakage, requiring frequent adjustments, and secondary seals experience axial movement causing fretting or shredding, while cooling mechanisms often have insufficient fluid circulation for effective heat transfer.

Innovation Solution

The implementation of a pumping ring with complex features such as sine waves, impeller, or core flow designs on the rotating ring drive ring, combined with a volute in the gland plate, enhances fluid circulation and heat transfer, minimizing vapor pockets and improving cooling efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a mechanical seal assembly is used to seal fluid in rotary shaft equipment, then sealing effectiveness is improved, but frictional wear between seal faces causes gaps and leakage requiring frequent adjustments

Engineering Contradiction:

Improvesealing effectivenessVSAvoidservice life between adjustments

Core Design Contradiction:

ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent changes the physical state of the seal faces by introducing a liquid film between them. This liquid film acts as a lubricant that reduces friction and wear, allowing the seal to maintain effectiveness over longer periods without adjustment. The parameter change from direct solid-to-solid contact to fluid-mediated contact resolves the contradiction between sealing effectiveness and service life.

Inventive Principle:

Principle #35Parameter changes

2Temperature

If flush liquid is provided to cool the seal faces, then cooling effectiveness is improved, but insufficient fluid circulation leads to inadequate heat transfer

Engineering Contradiction:

Improveseal face temperatureVSAvoidfluid circulation flow rate

Core Design Contradiction:

TemperatureVSProductivity

Solution Approach 1:

The pumping ring features curved surfaces and geometric shapes designed to optimize fluid flow patterns. The curved geometry creates efficient circulation paths that increase the flow rate of cooling liquid through the seal assembly, thereby improving heat transfer effectiveness while maintaining reasonable pump productivity requirements.

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Adaptability or versatility

If a dynamic secondary seal is configured to move axially with the seal member, then sealing adaptability is improved, but axial movement causes fretting or shredding of the secondary seal

Engineering Contradiction:

Improveseal adjustment capabilityVSAvoidsecondary seal durability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent introduces a liquid film as an intermediary between the secondary seal and the shaft or seal member. This liquid film reduces direct friction and contact stress on the secondary seal during axial movement, preventing fretting and shredding while allowing the seal to maintain its adaptability for adjusting to wear.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Productivity

If a pumping ring with complex features is implemented to enhance fluid circulation, then cooling efficiency is improved, but manufacturing complexity increases

Engineering Contradiction:

Improvefluid circulation flow rateVSAvoidpumping ring manufacturing

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The patent utilizes additive manufacturing technology to produce the pumping ring with its complex geometric features. This manufacturing approach transforms the ease of manufacture parameter by enabling the creation of intricate three-dimensional structures that would be difficult or impossible to achieve with traditional subtractive manufacturing methods, thereby allowing the complex flow-enhancing features to be produced efficiently.

Inventive Principle:

Principle #35Parameter changes

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 increases fluid circulation flow rates, leading to enhanced cooling of the mechanical seal components, reducing wear and leakage, and improving the overall performance and longevity of the seal assembly.

Implementation Method 1

The pumping ring can include complex features and may be formed, for example, by additive manufacturing. Examples of such features more fully described below include Sine Wave, Core Flow and Impeller features formed on the outer surface of the pumping ring.

Methodology Applied

Scientific EffectFluid circulation: Convection

Implementation Method 2

Also disclosed is volute that can be disposed within the gland (or other) plate that will surround the pumping/drive ring and can further improve cooling.

Methodology Applied

Scientific EffectHeat transfer: Convection

Implementation Method 3

Methodology Applied

Scientific EffectVapor pocket formation: Cavitation

Data Source

PatentUS20260063135A1Pumping ring for rotary shaft equipment seals

Publication Date: 2026.03.05 JOHN CRANE INC

AI summary

A mechanical seal assembly configured to be coupled to a rotating shaft of a machine, includes: rotating and stationary rings configured so that rotating ring rotates with the shaft and relative to the stationary ring; and a rotating ring drive ring that includes features formed at least on an outer surface thereof, the rotating drive ring configured to hold the rotating ring in a fixed relationship relative the rotating shaft. The features can increase the flow rate of cooling fluid near the seal when in operation.