Floating Labyrinth Shaft Seal for Misalignment and Low Wear
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing shaft seal assemblies fail to provide an adequate seal while allowing for acceptable shaft misalignment, leading to reduced efficiency and efficacy, especially in product seals where shaft to bore misalignment is maximized.
Innovation Solution
The proposed shaft seal assembly incorporates a labyrinth seal with a defined clearance and a floating stator with anti-rotation pins and o-rings, allowing for angular and radial misalignment while maintaining a tight seal through the use of pressurized sealing fluids and strategic anti-rotation mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the operating clearance between the rotating shaft and sealing members is increased to allow for shaft misalignment, then the adaptability to shaft misalignment is improved, but the sealing efficiency deteriorates
Solution Approach 1:
The seal assembly is divided into multiple sealing members arranged in series along the shaft, with each sealing member having its own defined clearance. This segmentation allows each sealing member to independently accommodate misalignment while maintaining effective sealing at multiple locations, preventing the trade-off between clearance and sealing efficiency.
Solution Approach 2:
The invention introduces a second dimension of clearance control by providing both a defined operating clearance and an additional clearance specifically for misalignment accommodation. This multi-dimensional clearance approach allows the seal to maintain tight sealing in the primary direction while having extra clearance capacity to handle angular and radial misalignment.
2Reliability
If the operating clearance is decreased to improve sealing efficiency, then the sealing efficiency is improved, but the adaptability to shaft misalignment deteriorates
Solution Approach 1:
Multiple sealing members are distributed along the shaft length, each maintaining tight clearances for effective sealing. The segmented structure ensures that even if one sealing member is affected by misalignment, others continue to provide effective sealing, thereby maintaining overall sealing efficiency while accommodating misalignment.
Solution Approach 2:
The invention adds an additional clearance dimension specifically dedicated to misalignment accommodation, separate from the primary operating clearance. This allows the sealing members to maintain tight operating clearances for high sealing efficiency while the additional clearance provides the necessary flexibility to handle shaft misalignment without compromising the seal.
3Reliability
If contact seals are used to maintain tight clearance, then the sealing efficiency is improved, but the wear resistance deteriorates due to contact with misaligned shaft
Solution Approach 1:
The invention introduces fluid pressure as an intermediary sealing mechanism that acts between the sealing members and the shaft. Pressurized fluid is introduced into the clearance spaces to create a pressure differential that prevents product leakage, eliminating the need for direct contact between sealing members and the shaft, thereby preventing wear while maintaining sealing efficiency.
Solution Approach 2:
The seal assembly utilizes pressurized fluid (pneumatic or hydraulic principle) introduced into the clearance spaces between sealing members and the shaft. This fluid pressure creates the necessary sealing force without mechanical contact, replacing contact-based sealing with fluid-based sealing that eliminates wear while maintaining effective sealing against product leakage.
4Duration of action of stationary object
If labyrinth seals are used to reduce wear, then the wear resistance is improved, but the sealing efficiency deteriorates due to dependence on close and defined clearance
Solution Approach 1:
The invention merges the wear-resistant labyrinth seal structure with active pressurized fluid sealing. The labyrinth seal provides the physical barrier and wear-resistant structure, while pressurized fluid introduced into the clearance spaces provides the active sealing force. This combination achieves both wear resistance from the labyrinth structure and high sealing efficiency from the fluid pressure differential.
Solution Approach 2:
Pressurized fluid acts as an intermediary that enhances the sealing capability of the labyrinth structure. The fluid is introduced into the clearance spaces created by the labyrinth seal geometry, creating a pressure differential that actively prevents leakage while the labyrinth structure provides the physical framework and wear resistance.
Data Source
AI summary
A shaft seal assembly comprises a stator configured to engage a housing and a rotor positioned within the stator. The stator may include a main body, a stator inward radial projection extending radially inward from the stator main body, and a collection groove adjacent the stator inward radial projection. The rotor may include a rotor main body and a rotor axial projection extending from the rotor main body. The rotor axial projection may be positioned adjacent a distal end of the stator inward radial projection.