Seal Ring Grooves for Torque Reduction and Leakage Prevention

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing seal rings fail to stably reduce rotational torque while preventing fluid leakage, especially when foreign matter is present, due to insufficient dynamic pressure generation and increased wear.

Innovation Solution

A seal ring with dynamic pressure generation grooves on its sliding surface, featuring a first groove with a shallower end and a second groove with a deeper bottom, guiding fluid and foreign matter, and a barrier to prevent fluid flow between grooves, ensuring effective torque reduction and foreign matter discharge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a groove is provided to guide sealed fluid to generate dynamic pressure, then rotational torque is reduced, but sealing performance deteriorates when foreign matter is present due to wear acceleration

Engineering Contradiction:
Improverotational torqueVSAvoidsealing performance
Core Design Contradiction:
ForceVSReliability

Solution Approach 1:

The groove is divided into two distinct segments: a first groove extending in the circumferential direction for dynamic pressure generation, and a second groove extending from the inner peripheral surface to the first groove for foreign matter discharge. This segmentation allows each groove to perform its specific function independently, resolving the contradiction between torque reduction and sealing performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The second groove acts as an intermediary channel that removes foreign matter from the sliding surface before it can enter the first groove. This intermediary structure protects the dynamic pressure generation function while maintaining the torque reduction effect.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a groove is provided to remove foreign matter from the sliding surface, then sealing performance is maintained, but sealed fluid leaks from the groove

Engineering Contradiction:
Improvesealing performanceVSAvoidfluid leakage
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The first groove is designed with non-uniform depth, being shallower at the ends and deeper at the center, creating a localized quality variation. This design allows the groove to discharge foreign matter effectively while maintaining fluid sealing through the deeper central region, preventing leakage.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The groove bottom surface is configured with a curved profile rather than a flat surface, creating a bowl-shaped structure that naturally directs fluid flow while containing foreign matter. This curvature enables effective foreign matter discharge without compromising fluid sealing.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Ease of manufacture

If the groove bottom is made uniform, then manufacturing is simplified, but dynamic pressure generation is insufficient due to inadequate wedge effect

Engineering Contradiction:
Improvegroove fabricationVSAvoiddynamic pressure
Core Design Contradiction:
Ease of manufactureVSForce

Solution Approach 1:

The groove depth parameter is varied along the circumferential direction, being shallower at the ends and deeper at the center. This parameter change creates the necessary wedge effect for dynamic pressure generation while remaining manufacturable through standard machining processes.

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

The seal ring effectively reduces rotational torque and prevents fluid leakage by generating dynamic pressure and discharging foreign matter, maintaining sealing performance and preventing wear.

Implementation Method 1

a pair of dynamic pressure generation grooves which are configured to have a groove bottom made shallower at an end in the circumferential direction than at a center in the circumferential direction

Methodology Applied
Scientific EffectDynamic pressure generation: Hydrodynamic Cavitation

Implementation Method 2

the dynamic pressure generation grooves are configured to have a groove bottom made shallower at an end in the circumferential direction than at a center in the circumferential direction, the above dynamic pressure can be effectively generated by a wedge effect

Methodology Applied
Scientific EffectWedge effect: Wedge

Implementation Method 3

a second groove extending from the inner peripheral surface to a position at which the second groove enters a central position of the first groove in the circumferential direction, guiding sealed fluid into the first groove, and capable of discharging foreign matter to a side of the inner peripheral surface

Methodology Applied
Scientific EffectFluid flow guidance: Advection

Implementation Method 4

seals the annular gap between the shaft and a housing that rotate relative to each other, to maintain fluid pressure in a sealed region in which the fluid pressure is configured to change

Methodology Applied
Scientific EffectPressure maintenance: Pressure Gradient

Data Source

PatentEP3273117B1Sealing ring
Publication Date: 2019.10.23 NOK CORP
  • EP3273117B1 patent drawingFigure 1
  • EP3273117B1 patent drawingFigure 2
  • EP3273117B1 patent drawingFigure 3

AI summary

Provided is a seal ring capable of stably reducing a rotational torque while preventing the leakage of sealed fluid. The seal ring includes, on a side of a sliding surface thereof, a groove part (120) having a first groove (121) extending in a circumferential direction thereof and a second groove (122) extending from a central position of the first groove (121) in the circumferential direction to an inner peripheral surface and guiding sealed fluid into the first groove (121), the first groove (121) having dynamic pressure generation grooves (121a) configured to have a groove bottom made shallower at an end thereof in the circumferential direction than at a center thereof in the circumferential direction, and a foreign matter catching groove (121b) that has a groove bottom deeper than the groove bottoms of the dynamic pressure generation grooves (121a) and is capable of catching foreign matter, and the first groove (121) being provided at a position that falls within a sliding region in which the seal ring slides on the lateral wall surface.