Bellows Mechanical Seal Adaptor Layout for Flexible Secondary Sealing
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Solution Overview
Problem
The existing bellows mechanical seals have limited flexibility in the arrangement of the collar and secondary seal due to the requirement of a radial wall for the annular recessed portion, restricting the configuration based on the collar shape.
Innovation Solution
The bellows mechanical seal incorporates a collar with a restriction piece and an adaptor that allows for axial movement restriction, enabling the collar to be compressed axially and expanded radially, allowing for a high degree of freedom in arrangement and compatibility with both rotating and stationary types, with the adaptor attached to either the inner or outer diameter side, and using materials like graphite, PTFE, or metal for the secondary seal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If an annular recessed portion is provided on each of the outer and inner diameter sides of the collar for O-ring disposal, then the collar can be used for both stationary and rotating types, but the collar structure becomes complex and arrangement flexibility is limited due to the need for radial wall portions
Solution Approach 1:
The invention extracts the O-ring disposal function from the collar structure by providing a separate annular groove in the adaptor rather than in the collar itself. This allows the collar to maintain a simple, unified structure while the adaptor handles the sealing function, resolving the contradiction between versatility and structural complexity
Solution Approach 2:
The adaptor serves as an intermediary component that bridges the collar and the housing/rotary shaft. It provides the annular groove for O-ring disposal and the housing space for the secondary seal, allowing the collar to remain simple while achieving adaptability through the mediator component
2Adaptability or versatility
If the collar and secondary seal are arranged with fixed positions, then the structure is stable, but the arrangement flexibility and space utilization are limited
Solution Approach 1:
The invention makes the adaptor axially movable relative to the collar within a predetermined range, allowing dynamic adjustment of the secondary seal position. The restriction piece prevents excessive movement while enabling flexible arrangement, resolving the contradiction between stability and adaptability
Solution Approach 2:
The invention segments the assembly into collar, adaptor, and secondary seal as separate components with relative movement capability. This segmentation allows independent positioning and adjustment while maintaining overall structural integrity through the restriction mechanism
3Reliability
If the secondary seal uses less elastic materials like graphite, PTFE, or metal, then the sealing performance is maintained, but the seal requires more precise arrangement and housing space
Solution Approach 1:
The axially movable adaptor allows dynamic adjustment to accommodate variations in secondary seal dimensions and compression requirements. This dynamic positioning capability reduces the stringency of arrangement precision requirements while maintaining reliable sealing with less elastic materials
Solution Approach 2:
The invention allows adjustment of the adaptor position to change the compression amount applied to the secondary seal. This parameter adjustment capability enables optimal sealing performance with less elastic materials by fine-tuning the compression force without requiring extremely precise initial arrangement
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 configuration allows for a high degree of freedom in arranging the collar and secondary seal, reducing the occupied space and enabling the use of a common collar for both types, while maintaining effective sealing performance even with less elastic materials.
Implementation Method 1
The collar is slightly compressed in the axial direction while slightly expanding in the radial direction, and is directly or indirectly fixed to the housing or the rotary shaft in the axial direction
Data Source
Figure 1(a)~1(b)
Figure 2
Figure 3
AI summary
There is provided a bellows mechanical seal with a high degree of freedom in arrangement of a collar and a secondary seal. In a bellows mechanical seal (1), a collar (3) attached to a seal ring (15) through a bellows (13) has a restriction piece (4), (8) extending toward at least one of an inner diameter side or an outer diameter side. The bellows mechanical seal (1) includes an adaptor (50), (70) which is attached to the collar (3), whose axial movement is restricted by the restriction piece (4), (8), and which extends to the inner diameter side or the outer diameter side over the restriction piece (4), (8). The collar (3) and the adaptor (50), (70) form at least part of a housing space (S), (S') having the secondary seal (60), (80) housed therein.