Compact Mechanical Seal Layout for Reduced Axial Bulk

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Solution Overview

Problem

Existing mechanical seals used in rotating machines are often complex and require strict manufacturing tolerances, leading to a need for a compact and simpler design that maintains effective sealing and sliding functionality.

Innovation Solution

A seal design featuring a friction ring with a cylindrical external surface, a compression spring that extends around the friction ring, and a transmission element with a cylindrical wall that cooperates with the friction ring to transmit forces, reducing axial bulk and allowing for simpler production without strict tolerance requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the spring element is located on the side of the friction ring opposite the rotor, then the seal structure is simple, but the axial size of the seal becomes relatively large

Engineering Contradiction:
Improveseal structure complexityVSAvoidaxial size of the seal
Core Design Contradiction:
Device complexityVSLength of moving object

Solution Approach 1:

The patent repositions the spring element from the traditional axial position (opposite the rotor) to a radial position (substantially in line with the friction ring). This dimensional change allows the spring to exert force through a different spatial arrangement, reducing the axial footprint of the seal while maintaining the necessary sealing pressure through the friction ring.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Length of moving object

If the spring element is located substantially in line with the friction ring radially, then the axial size of the seal is reduced, but the friction ring structure becomes relatively complex

Engineering Contradiction:
Improveaxial size of the sealVSAvoidfriction ring structure complexity
Core Design Contradiction:
Length of moving objectVSDevice complexity

Solution Approach 1:

The patent integrates the spring element and friction ring into a unified radial arrangement where the spring's force is transmitted directly through the friction ring's radial structure. This merging of components eliminates the need for separate axial positioning mechanisms, reducing overall structural complexity despite the radial repositioning.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If the seal is sandwiched radially between the friction ring and housing part, then sealing is ensured, but strict manufacturing tolerances are required

Engineering Contradiction:
Improvesealing effectivenessVSAvoidmanufacturing tolerances
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent changes the geometric parameters of the seal arrangement by positioning the spring radially in line with the friction ring rather than axially. This parameter change allows for greater tolerance in manufacturing because the radial force distribution is more forgiving of dimensional variations, while still maintaining effective sealing through the friction ring's contact with the rotor.

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 design results in a compact, axially reduced seal that maintains effective sealing and sliding functionality, simplifying production and reducing material usage while ensuring reliable operation across various rotating machines.

Implementation Method 1

A spring element housed inside the stator usually exerts pressure on a friction ring internal to the stator

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

dynamic sealing between a rotating shaft and a stationary body

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3966477B1Compact seal for sealing between a rotating shaft and a stationary body of a machine
Publication Date: 2023.11.22 CYCLAM
  • EP3966477B1 patent drawingFigure 1~3

AI summary

The invention relates to a compact seal (10) providing dynamic sealing between a rotating shaft and a stationary body, in particular a stationary chamber. The seal (10) comprises in particular a compression spring (16) supported against a transmission element (18) for transmitting the forces of the spring to a friction ring (12) and pressing same against a counter-ring (14). The compression spring (16) is supported against a first radial rim (181) of the transmission element (18), a second rim (182) of the transmission element (18) being located partly opposite a radial surface (122) of the friction ring remote from the counter-ring (14) and a cylindrical wall (180) of the transmission element (18) being located partly opposite the cylindrical outer surface (124) of the friction ring (12).