Slinger Groove Sealing Structure for Static Leak Prevention

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Solution Overview

Problem

Conventional end-face contact-type sealing apparatuses face static leakage issues when the slinger is stopped, leading to increased sliding resistance, which is undesirable for reducing fuel consumption in vehicles.

Innovation Solution

A sealing apparatus with a slinger featuring shallow grooves, each with a depth of equal to or less than 10 µm, intersecting with the seal lip contact area to prevent static leakage without increasing sliding resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a seal lip on the inner periphery side is added to prevent static leakage, then static leakage is prevented, but sliding resistance increases

Engineering Contradiction:
Improvestatic leakage preventionVSAvoidsliding resistance
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The invention changes the geometric parameters of the grooves by strictly controlling their depth to be 5 µm or less. This parameter optimization allows the grooves to prevent static leakage while minimizing their impact on sliding resistance, resolving the contradiction between sealing reliability and frictional force

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention applies different functional properties to different regions: the shallow grooves provide static leakage prevention at specific locations, while the overall seal lip structure maintains low sliding resistance. The localized groove structure ensures that sealing function is enhanced without proportionally increasing friction

Inventive Principle:
Principle #3Local quality

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

The sealing apparatus effectively prevents static leakage while maintaining low sliding resistance, as demonstrated by evaluation tests showing no leakage for extended periods with groove depths of 8 µm or less.

Implementation Method 1

the slinger has a plurality of shallow grooves... a depth of each of the grooves is equal to or less than 10 μm... the groove intersects with a portion where the seal lip contacts

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Data Source

PatentEP3633245B1Sealing device
Publication Date: 2022.04.20 NOK CORP
  • EP3633245B1 patent drawingFigure 1
  • EP3633245B1 patent drawingFigure 2
  • EP3633245B1 patent drawingFigure 3

AI summary

A sealing apparatus which can prevent static leakage of a target to be sealed without increasing sliding resistance with respect to a shaft is provided. A sealing apparatus (1) includes a sealing apparatus body (2) and a slinger (3), and the sealing apparatus body (2) includes an annular reinforcing ring (10) and an annular elastic body portion (20). The slinger (3) includes a flange portion (31) which is an annular portion extending toward an outer periphery side. The elastic body portion (20) includes an annular end-face lip (21) which extends toward an inner side and which contacts an outer side surface (31d) of the flange portion (31). At least one shallow groove (33) is formed on the outer side surface (31d) of the flange portion (31) of the slinger (3).