Torque-Resistant Dual Face Seal With Anti-Spin Load Ring Grip

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Solution Overview

Problem

Existing seal assemblies for machines used in earth moving, agricultural, and construction applications face challenges in preventing the loss of lubrication and the inflow of debris, especially in harsh environments and challenging terrains.

Innovation Solution

A dual face seal assembly featuring a seal ring with an L-shaped cross-section and an annular seal face, along with a load ring interface that includes deformations for improved grip and sealing, is used to enhance the sealing effectiveness and prevent debris entry.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional face seal assembly is used, then the seal can retain lubricant and exclude foreign matter, but the load ring may spin or slip on the seal ring under high torque conditions

Engineering Contradiction:
Improveseal performanceVSAvoidtorque resistance
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The loading surface of the seal ring is given a non-uniform geometry with deformations (dimples, grooves, or raised portions) that create localized high-friction zones. These local geometric features increase the coefficient of friction specifically at the load ring-seal ring interface, preventing spinning and slippage under torque without affecting the overall seal design

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The loading surface incorporates curved or non-planar features such as dimples and grooves instead of a flat surface. These curved geometries increase the contact area and mechanical interlocking between the load ring and seal ring, thereby enhancing torque resistance and preventing relative rotation

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Ease of manufacture

If the loading surface is made smooth and uniform, then the manufacturing is simpler, but the contact area and grip between load ring and seal ring are reduced

Engineering Contradiction:
Improveloading surface fabricationVSAvoidcontact area
Core Design Contradiction:
Ease of manufactureVSArea of stationary object

Solution Approach 1:

The loading surface is segmented into multiple discrete deformation features (dimples, grooves, raised portions) distributed across the surface. This segmentation increases the effective contact area and creates multiple contact points that enhance grip, while the features can be manufactured using standard machining or forming operations

Inventive Principle:
Principle #1Segmentation

3Ease of manufacture

If the seal ring has a simple cylindrical shape, then the manufacturing is easier, but the sealing effectiveness and torque resistance are insufficient

Engineering Contradiction:
Improveseal ring fabricationVSAvoidsealing effectiveness
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The seal ring incorporates localized geometric features (L-shaped, U-shaped, or V-shaped cross-sections) in specific regions to enhance sealing effectiveness and torque resistance, while maintaining a generally simple cylindrical overall shape that is easy to manufacture

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The seal ring cross-section is made asymmetric with L-shaped, U-shaped, or V-shaped profiles instead of a symmetric cylindrical shape. This asymmetry creates mechanical interlocking and increases contact area for improved sealing and torque resistance, while still being manufacturable using standard forming operations

Inventive Principle:
Principle #4Asymmetry

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 dual face seal assembly effectively minimizes failures by increasing contact area and grip between the load ring and the seal ring, preventing spinning, leaking, galling, and packing, while also keeping debris out of the seal assembly.

Implementation Method 1

The deformations increase the friction between the load ring and the seal ring

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3990807B1Torque resistant seal
Publication Date: 2025.02.19 CATERPILLAR INC
  • EP3990807B1 patent drawingFigure 1
  • EP3990807B1 patent drawingFigure 2
  • EP3990807B1 patent drawingFigure 3

AI summary

A torque-resistant dual face seal includes a seal ring (110, 112) having an L-shaped cross-section including an axially-extending flange (140, 142) and a radially-extending flange (126, 128), the seal ring including an annular seal face (118, 120) and an annular loading surface (134, 136). The seal ring includes a plurality of deformations (138) formed in a spaced apart arrangement circumferentially around the axially-extending flange. An axial cross-section through the axially-extending flange and intersecting one of the plurality of deformations includes a stepped geometry. The plurality of deformations allows a load ring (114, 116) to squeeze into the plurality of deformations to increase a surface area contact between the seal ring and the load ring.