Hub-Wheel Sealing Device Screen Interference Fit Optimization
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Solution Overview
Problem
Current sealing devices for hub-wheel assemblies with rolling bearings suffer from increased water infiltration due to a conical shape of the annular cylindrical wall resulting from suboptimal interference and coupling length between the metallic screen and the bearing outer ring, compromising sealing quality.
Innovation Solution
Optimizing the interference and coupling length between the sealing device's screen and the bearing outer ring, with specific ratios and geometries, reduces the conical shape of the annular cylindrical wall to nearly zero, enhancing static sealing by ensuring proper alignment and compression of the elastomeric sealing lip.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the interference and coupling length between the metallic screen and bearing outer ring are increased to ensure secure mounting, then the mounting reliability is improved, but the annular cylindrical wall develops a conical shape that deteriorates sealing quality
Solution Approach 1:
The patent applies parameter changes by optimizing the interference fit values and coupling length dimensions between the metallic screen and bearing outer ring. By carefully selecting and adjusting these parameters within specific ranges, the solution achieves both secure mounting (preventing screen detachment) and maintains cylindrical geometry (preventing conical deformation), thereby resolving the contradiction between mounting reliability and sealing quality
Solution Approach 2:
The patent implements beforehand cushioning by designing the press-fit interface with optimized interference values that prevent excessive deformation during assembly. The coupling length and interference parameters are pre-calculated to cushion against the development of conical shape, ensuring the annular cylindrical wall maintains its geometry even under mounting stresses
2Strength
If the interference fit between screen and bearing outer ring is increased to prevent screen detachment, then the connection strength is improved, but the conical deformation of the annular cylindrical wall increases which worsens water infiltration
Solution Approach 1:
The patent resolves this contradiction by changing the parameters of interference fit and coupling length to optimal values. The interference fit is set within a specific range that provides sufficient connection strength to prevent screen detachment while remaining low enough to avoid excessive radial forces that would cause conical deformation and water infiltration
Solution Approach 2:
The patent converts the potentially harmful effect of interference fit into a beneficial outcome by optimizing its magnitude. The interference fit is designed to be just sufficient to secure the screen during operation, transforming what could be a source of deformation into a controlled mounting mechanism that ensures both connection strength and sealing integrity
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 significantly reduces water infiltration, maintaining effective sealing throughout the bearing's lifetime by ensuring optimal contact pressure and sealing force, thereby improving the sealing device's performance.
Implementation Method 1
the screen comprises an annular cylindrical wall, whose internal lateral surface is coupled by means of said press fit operation with the external lateral surface of a collar of the bearing outer ring
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
Sealing device (1, 11) for a hub-wheel assembly (2) provided with a rolling bearing (3), the sealing device being provided with a screen (6, 16), which is assembled on an outer ring (4) of the bearing (3) and has an annular cylindrical wall (61, 161), having an internal lateral surface (62, 162) which is press fit along an external lateral surface (42) of a collar (41) of the outer ring (4), the internal internal surface (62, 162) showing a respective inner diameter (Di) and the external lateral surface (42) showing a respective outer diameter (De); and a static sealing element (7, 17), constrained to said screen (6, 16); the ratio of the interference between inner diameter (Di) and outer diameter (De) over a screen thickness ranging between 0.22 and 0.5; a coupling length (L, L') between the internal lateral surface (62, 162) and the external lateral surface (42) equal or greater than 5 mm; and a ratio between outer diameter (De) of the external lateral surface (42) and coupling length (L, L') ranging between 1 and 1.19.