Stepped Compressor Seal With Abradable Teeth for Leakage Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional refrigerant compressors experience significant leakage due to the design of traditional seals, which affects the efficiency and performance of refrigeration systems, particularly in HVAC chiller systems.
Innovation Solution
The implementation of a step seal design in refrigerant compressors, featuring a rotor and stator configuration with angled teeth and abradable portions, which creates recirculation zones and minimizes clearance between components to reduce fluid leakage, utilizing a stepped arrangement and abradable materials to carve tracks and maintain a minimal gap, thereby enhancing sealing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If traditional seals are used in refrigerant compressors, then the structure is simple and ease of manufacture is good, but fluid leakage is significant and efficiency deteriorates
Solution Approach 1:
The seal structure is divided into multiple discrete teeth (first tooth, second tooth, third tooth) arranged in a stepped configuration. Each tooth creates separate sealing zones and recirculation cavities, breaking the continuous leakage path into multiple segments that must be overcome sequentially, thereby reducing total fluid leakage while maintaining manageable structural complexity
Solution Approach 2:
The seal design transitions from a traditional single-plane sealing surface to a three-dimensional stepped structure with teeth extending radially outward at different heights. This dimensional change creates multiple sealing levels and recirculation zones, effectively reducing leakage by forcing fluid to navigate complex multi-level paths rather than flowing directly across a single plane
2Loss of energy
If clearance between rotor and stator is increased, then ease of operation and manufacturing tolerance are improved, but fluid leakage increases and efficiency decreases
Solution Approach 1:
The abradable material is applied locally to specific portions of the stator teeth (first abradable portion, second abradable portion, third abradable portion) rather than uniformly across the entire stator. This localized treatment allows the rotor teeth to carve precise tracking patterns only where needed for sealing, maintaining tight effective clearance in critical areas while preserving manufacturing tolerance in non-critical areas
Solution Approach 2:
The abradable material is pre-applied to the stator teeth surfaces before operation. During initial operation, the rotor teeth automatically carve the required tracking patterns into this pre-applied material, preparing the optimal sealing geometry in advance. This preliminary action ensures that the precise clearance and tracking patterns are established before full operational loads are applied, reducing leakage without requiring extremely tight initial manufacturing tolerances
3Reliability
If abradable material is applied to stator teeth, then sealing effectiveness is improved over time, but manufacturing complexity and cost increase
Solution Approach 1:
The abradable material on the stator teeth is designed to be self-forming during operation. The rotor teeth automatically carve the required tracking patterns into the abradable material through normal operational contact, without requiring external machining or adjustment. This self-service mechanism allows the seal to automatically optimize its own geometry during operation, improving reliability while avoiding complex pre-machining processes
Solution Approach 2:
The material properties of the stator tooth surfaces are changed by applying abradable material with specific erosive characteristics. This parameter change allows the material to be easily removed by the rotor teeth during operation, forming precise tracking patterns that enhance sealing. The key is selecting abradable materials that balance ease of carving during operation with sufficient durability for long-term service
4Productivity
If stepped seal design with multiple teeth is implemented, then fluid leakage is reduced significantly, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The stepped seal structure is implemented by nesting multiple teeth of decreasing radial height in sequence (first tooth with greatest height, second tooth with intermediate height, third tooth with least height). Each tooth is nested within the radial space defined by the previous tooth, creating a compact multi-level structure that maximizes sealing effectiveness within the available radial envelope while avoiding excessive overall complexity
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 design reduces total leakage by 40-80% compared to conventional seals, improving the overall efficiency and performance of refrigerant compressors by passively controlling fluid flow and maintaining effective sealing over time.
Implementation Method 1
the first and second teeth are configured to contact the abradable portion and carve tracks into the abradable portion over time
Data Source
AI summary
In some aspects, the techniques described herein relate to a refrigerant compressor, including: a stator; a rotor configured to rotate with respect to the stator; and at least one step seal between the rotor and the stator, wherein the step seal includes a first tooth and a second tooth extending from the rotor toward the stator, wherein a downstream surface of the first tooth and an upstream surface of the second tooth are arranged at an angle relative to one another, wherein the angle is less than 90°.