Seal Ring Gap Structure for Low-Resistance Scroll Compression

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Solution Overview

Problem

Conventional scroll compressors face increased sliding resistance due to the eccentric rotation of the seal ring, which leads to a decrease in rotary driving force and efficiency, and the wear of the contact portion results in further resistance increase over time.

Innovation Solution

A seal ring with annular surfaces featuring recessed portions that form a gradually decreasing gap with wear, reducing sliding resistance by maintaining a consistent contact area despite wear.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the seal ring is configured to slide with respect to the movable scroll or thrust plate during eccentric rotation, then the seal ring can close the gap and seal the low-pressure chamber, but sliding resistance increases and reduces the rotary driving force

Engineering Contradiction:
Improvesealing performanceVSAvoidrotary driving force
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The patent introduces a lubricant as an intermediary substance between the seal ring and the movable scroll/thrust plate. The lubricant forms a film that reduces direct contact and sliding resistance, allowing the seal ring to maintain sealing performance while reducing the force required for eccentric rotation. This is achieved by providing lubricating grooves that supply lubricant to the contact surfaces.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the physical parameters of the contact interface by introducing a lubricant film. This alters the friction characteristics and reduces the sliding resistance. The lubricant film thickness and viscosity are controlled through the groove design, transforming the dry friction condition into a lubricated condition, thereby reducing the rotary driving force requirement.

Inventive Principle:
Principle #35Parameter changes

2Duration of action of moving object

If the seal ring contact portion is allowed to wear with use, then the seal ring can maintain sealing function, but the contact portion deforms and sliding resistance increases over time

Engineering Contradiction:
Improveservice lifeVSAvoidsliding resistance
Core Design Contradiction:
Duration of action of moving objectVSForce

Solution Approach 1:

The patent incorporates lubricating grooves into the seal ring structure before use. These grooves are pre-designed to supply lubricant to the contact surfaces, preventing direct metal-to-metal contact from the beginning of operation. This preliminary lubrication action prevents wear-induced deformation and maintains low sliding resistance throughout the service life of the seal ring.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The lubricant acts as a mediator between the seal ring and the movable scroll/thrust plate, preventing direct contact and wear. The lubricating grooves ensure continuous supply of this intermediary substance, maintaining the protective film even after extended operation, thereby preventing the increase in sliding resistance that would normally occur with wear.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If the seal ring is made to eccentrically rotate along with the movable scroll, then the seal ring can follow the compression chamber movement, but sliding resistance creates a resistance to the rotary driving force

Engineering Contradiction:
Improveeccentric rotation capabilityVSAvoidcompressor efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The lubricant introduced through the grooves serves as a mediator that enables the seal ring to eccentrically rotate with the movable scroll while minimizing friction. This allows the seal ring to maintain adaptability to the compression chamber movement without significantly increasing sliding resistance, thereby preserving compressor efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the friction parameters at the contact interface through lubrication, allowing the seal ring to undergo eccentric rotation with reduced resistance. This parameter change enables the seal ring to follow the movable scroll's motion while minimizing the negative impact on the rotary driving force and overall compressor efficiency.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4600531A1Seal ring
Publication Date: 2025.08.13 NOK CORP
  • EP4600531A1 patent drawingFigure 1
  • EP4600531A1 patent drawingFigure 2
  • EP4600531A1 patent drawingFigure 3

AI summary

A seal ring (1) is in an annular shape around an axis (x) and the seal ring has: a one-side surface (1a) that is an annular surface facing one side in a direction of the axis (x); and an opposite-side surface (1b) that is an annular surface facing an opposite side in the direction of the axis (x). When being in contact with one or the other one of a movable scroll and a thrust plate of an installation object, at least one of the one-side surface (1a) and the opposite-side surface (1b) is configured to form a gap (1c) between the one or the other one of the two members and the at least one of the one-side surface and the opposite-side surface. The gap (1c) is configured to gradually decrease with wear of the at least one of the one-side surface (1a) and the opposite-side surface (1b) due to the contact with the movable scroll and the thrust plate.