Countersunk Threaded Bearing for Sloped Surface Installation
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Solution Overview
Problem
Conventional bearing installations require interference fits, material displacement, and flat surfaces, which increase complexity and manufacturing costs, and can be challenging in structures with sloped surfaces or limited accessibility.
Innovation Solution
A bearing assembly with an outer race having a countersink lip and externally threaded portion, allowing for a clearance fit and installation without interference fits, using a nut to secure the assembly in a structural hole with a countersink profile, enabling easy removal and installation without damaging the hole or bearing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional bearing installation methods are used, then the bearing can be secured in the hole, but interference fit and material displacement are required which increase installation complexity and can damage the hole or bearing
Solution Approach 1:
The bearing assembly is divided into separate components: an outer race with threaded portion, an inner race, and a separate locking nut. This segmentation allows the bearing to be installed without interference fit, as the threading provides mechanical retention while the nut provides locking capability, eliminating the need for complex press-fitting or staking operations.
Solution Approach 2:
Instead of forcing the bearing into the hole with interference fit, the patent inverts the approach by using a clearance fit with external threading and a locking nut. The retention mechanism is inverted from internal interference to external mechanical fastening, simplifying installation and allowing easy removal and replacement.
2Ease of operation
If flanged bearings are used, then the bearing can be supported during installation, but a flat surface surrounding the hole is required which may not be available in structures with sloped surfaces
Solution Approach 1:
The bearing assembly is designed to be universally applicable to various surface conditions. The outer race with threaded portion and locking nut configuration can be installed on flat surfaces, sloped surfaces, and in locations with limited accessibility. The design eliminates the requirement for a flat surrounding surface by using the hole geometry itself (with countersink) and the threading mechanism for retention.
Solution Approach 2:
The patent moves the retention mechanism from relying on surface geometry (flat surface around hole) to relying on the dimensional features of the hole itself (countersink profile and threaded portion extending through the structure). This dimensional shift allows installation in various surface conditions including sloped surfaces where draft angles prevent flat surface creation.
3Reliability
If press-fit bearing installation is used, then the bearing is secured in the hole, but replacement may result in damage to the hole or bearing making them non-reusable
Solution Approach 1:
The bearing assembly transitions from a static press-fit configuration to a dynamic, reversible fastening system. The locking nut can be loosened and tightened, allowing the bearing to be easily removed and reinstalled multiple times without damage. The threading and locking mechanism provide retention during operation but allow simple replacement when needed, eliminating the permanent damage issue associated with press-fit installations.
Data Source
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Figure 5
AI summary
A bearing assembly includes an outer race, an inner race, a bearing interface, and a nut. The outer race has a head end and a base end. The head end includes a flange having a countersink lip formed on an underside of the flange. The outer race includes an externally threaded portion terminating at the base end. The inner race is circumscribed by the outer race. The bearing interface is located between and rotatably couples the inner race to the outer race. The nut is configured to be threadably engaged to the externally threaded portion.