Spherical Pivot Column Bearing for Fin Stabilizer Misalignment
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Solution Overview
Problem
Existing pivot column bearings for fin stabilizers in watercraft suffer from misalignment issues due to thermal stresses during welding, leading to jamming, damage, and noise, and require manual adjustments to compensate for misalignment, which is inefficient and can cause further damage.
Innovation Solution
The pivot column bearing features spherical plain bearing surfaces in both the upper and lower bearings, allowing automatic compensation of misalignment through sphericity, ensuring constant play and optimal fit, and includes a lubrication system to minimize switching clicks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If axial and/or radial play is provided to compensate for misalignment, then misalignment compensation is improved, but bearing clearance becomes too large when misalignment is minimal, leading to damage and noise
Solution Approach 1:
The patent applies spherical plain bearing surfaces instead of cylindrical ones. The spherical geometry allows the bearing to automatically compensate for misalignment through its ability to accommodate angular offsets while maintaining constant play. The spherical surface enables the bearing to self-adjust to misalignment errors without requiring excessive clearance, thus preventing both misalignment damage and the harmful effects of excessive play when misalignment is minimal.
2Manufacturing precision
If spherical plain bearing surfaces are used for automatic misalignment compensation, then manufacturing precision is improved, but device complexity increases due to the need for spherical surfaces
Solution Approach 1:
The patent implements spherical plain bearing surfaces that combine manufacturing precision with functional simplicity. The spherical geometry, while slightly more complex than cylindrical surfaces, provides inherent misalignment compensation capabilities and enables optimal fit through constant play maintenance. The spherical design actually simplifies the overall system by eliminating the need for complex adjustment mechanisms.
3Reliability
If manual adjustments are made to compensate for misalignment, then bearing operation reliability is improved, but ease of operation deteriorates due to required corrective measures
Solution Approach 1:
The patent employs self-service principles through the spherical plain bearing surfaces that automatically compensate for misalignment without requiring manual intervention. The spherical geometry enables the bearing to self-adjust to misalignment errors through its inherent ability to accommodate angular offsets, eliminating the need for shimming, reworking, or other corrective measures during installation and maintenance.
4Ease of manufacture
If cylindrical plain bearing surfaces are used, then ease of manufacture is improved, but reliability deteriorates due to misalignment-induced jamming and damage
Solution Approach 1:
The patent transitions from cylindrical to spherical plain bearing surfaces. While spherical surfaces require slightly more complex manufacturing than cylindrical ones, they provide superior reliability by automatically compensating for misalignment. The spherical geometry allows the bearing to accommodate thermal expansion and welding-induced misalignment without jamming or damage, making the additional manufacturing complexity worthwhile for the significant reliability improvement.
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 solution effectively compensates for misalignment automatically, reducing the risk of damage and noise, ensuring reliable operation without the need for manual adjustments, and maintaining optimal load transmission.
Implementation Method 1
the upper bearing and/or the lower bearing have spherical plain bearing surfaces... misalignment or angular offsets between the plain bearings can be compensated for while maintaining a constant level of play
Implementation Method 2
The lubricant is supplied in such a way that when the load direction is switched, the lubricant is pressed through the bearings and corresponding free spaces like grease
Data Source
Figure 1
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AI summary
Disclosed is a pivot column bearing for a fin stabilizer of watercraft, which has at least one spherical plain bearing, and a fin stabilizer.