Mechanical Seal Ring Fixation via Nested Sleeve and Collar

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Solution Overview

Problem

Conventional methods for fixing a rotational ring to a rotary shaft require significant space and are prone to issues like erosion, abrasion, and distortion under varying pressure conditions, leading to potential seal failures.

Innovation Solution

A mechanical seal device with a rotational ring, a stationary ring, and a rotational ring fixing portion that includes a sleeve and a collar, allowing for compact fixation without large axial or radial space requirements, and maintaining stable sealing performance under both positive and negative pressures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional fixation methods (set screw, sleeve, seal nut) are used to fix the rotational ring, then the rotational ring can be securely fixed, but the device requires considerable space in both axial and radial directions

Engineering Contradiction:
Improvefixation stabilityVSAvoidaxial and radial space
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The rotational ring fixing collar is fitted inside the sleeve, creating a nested structure where one component is placed within another. This nesting arrangement allows the fixation mechanism to occupy minimal space while maintaining secure fixation of the rotational ring through the combined action of the collar and knock pin.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Device complexity

If a snap ring is used to fix the rotational ring, then the structure is simple and compact, but the snap ring may come off due to erosion and abrasion from exposure to inside liquid medium

Engineering Contradiction:
Improvestructure simplicityVSAvoidfixation durability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The rotational ring fixing collar acts as an intermediary component between the sleeve and the rotational ring. It provides a protected interface that prevents direct exposure of the fixation elements to the corrosive liquid medium, while still maintaining the simplicity of the snap ring structure for compact fixation.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If only a positive pressure is applied to the rotational ring, then simple fixation methods work, but under negative pressure the rotational ring may come off or cause distortion

Engineering Contradiction:
Improvefixation method simplicityVSAvoidpressure condition adaptability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The rotational ring fixing collar provides localized support at specific points on the rotational ring. This localized fixation structure creates asymmetric support that is optimized for handling negative pressure conditions, while maintaining overall structural simplicity. The collar's positioning and geometry are specifically designed to prevent ring displacement under suction.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2455641B1Mechanical sealing device
Publication Date: 2015.09.09 EAGLE INDS
  • EP2455641B1 patent drawingFigure 1
  • EP2455641B1 patent drawingFigure 2
  • EP2455641B1 patent drawingFigure 3

AI summary

Provided is a mechanical sealing device which is simply configured and wherein a rotation ring can be stably held in a specified axial position, and warping of the sealed surfaces can be prevented, thereby making it possible to obtain appropriate sealing characteristics. In a mechanical sealing device (1), a rotation ring (31) is axially held between a rotation ring locking surface (214) of a sleeve (21) and a rotation ring locking surface (225) of a collar (22). Furthermore, the sleeve (21), the rotation ring fixing collar (22), and the rotation ring (31) are integrated together by means of a baffle knock pin (23) for the rotation ring (31). Due to the above, whether positive pressure or negative pressure is applied, the rotation ring (31) does not move, nor do the sealed surfaces of the rotation ring (31) become warped. Moreover, assembly can be simply performed only by means of the knock pin (23).