Self-Aligning Miniature Ball Bearings with Press-Fit Mounting
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Solution Overview
Problem
There is a need for miniature self-aligning ball bearings that can be easily press-fit into openings in mounting blocks and thin sheet materials, as existing solutions are costly and require precise machining, and no such self-clinching or press-fitable ball bearings are available for small diameter shafts under 0.5 inches.
Innovation Solution
A self-aligning miniature ball bearing assembly with a retainer having a spherical outer wall and an elastomeric compression ring, allowing the ball bearing to move within the retainer and self-align, which can be either self-clinching or press-fit, suitable for shaft sizes up to 0.375 inches in diameter, including those in precision machinery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional mounting methods with mounting collars and dogs are used, then bearing alignment precision is improved, but manufacturing cost and complexity increase
Solution Approach 1:
The patent removes the mounting collar and alignment dogs from the system, extracting only the essential functions of mounting and alignment into the bearing assembly itself. The bearing outer race is directly press-fit into the mounting block opening, eliminating the need for separate mounting components while maintaining alignment precision through the self-aligning mechanism.
Solution Approach 2:
The patent combines the mounting function and alignment function into a single integrated bearing assembly. The outer race incorporates both the mounting interface (press-fit surface) and the self-aligning mechanism (spherical interface with conical surface), merging multiple functions into one component to reduce complexity.
2Manufacturing precision
If precise machining of mounting holes and collars is performed, then bearing alignment is improved, but manufacturing time and cost increase
Solution Approach 1:
The bearing assembly performs self-alignment through its own spherical outer race and conical retainer surface interface. The bearing automatically orients itself during press-fit installation without requiring pre-machined alignment features or precision positioning of mounting holes, making the system self-servicing for alignment functions.
Solution Approach 2:
The patent changes the geometric parameters of the bearing interface from precise cylindrical fits to spherical-conical interfaces. The spherical outer race with conical retainer surface allows for angular adjustment and self-centering during installation, transforming the alignment requirement from a precision positioning problem to a self-adjusting geometric relationship.
3Manufacturing precision
If multiple precision machining steps are used, then bearing mounting accuracy is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent segments the bearing assembly into distinct functional zones: the spherical outer race for self-alignment, the conical retainer surface for positioning, and the press-fit interface for mounting. Each zone performs a specific function, allowing simple manufacturing processes to achieve high overall mounting accuracy through the coordinated action of segmented features.
4Reliability
If ball bearings are used instead of roller bearings or bushings, then rotation rate and load capacity are improved, but self-aligning and press-fit capabilities are reduced
Solution Approach 1:
The patent applies spheroidality by giving the ball bearing outer race a spherical outer surface that interfaces with a conical surface in the retainer. This spherical-conical interface enables the ball bearing to pivot and self-align within the retainer, providing adaptability that is typically associated with larger roller bearings or bushings but not with miniature ball bearings.
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 reduces the need for precise machining and labor-intensive installation, providing a cost-effective and precise alignment of ball bearings in various applications, including printers, medical, and research equipment, with improved shock resistance and reduced friction.
Implementation Method 1
an elastomeric compression ring disposed in a groove at one end of the retainer. The ball bearing is able move within the retainer
Implementation Method 2
a ball bearing (13) mounted in the retainer (12) and held in place by the compression ring (10). The ball bearing (13) is able move within the retainer (12) so that its axis can assume any orientation within a cone around the axis of the retainer (12)
Implementation Method 3
Rolling bearings offer high lateral load bearing capability and have low frictional resistance to accommodate higher rotation rates than static bushings
Data Source
Figure 1~2
Figure 2A~2C
Figure 3~5
AI summary
A self-aligning miniature ball bearing assembly 11 is disclosed for being pressed into an opening formed in a substrate such as a sheet 21, a pillar block 17, a mounting flange 16, or a shaft 19. In one embodiment, the assembly is self-clinching when pressed into the opening and in an alternate embodiment the assembly is press-fitable into the opening and held with a friction fit. The miniature ball bearing 13 of the assembly is mounted within a retainer 12 and held against an angled bearing seat by a elastomeric compression ring 10. This allows the axis of the ball bearing to assume any orientation within a cone having a half angle of about 5 degrees with respect to an axis of the retainer. The ball bearing 13 is thereby self-aligning upon receiving a shaft to be rotationally mounted in the assembly 11.