Crown-Shaped Ball Bearing Retainer for High-Speed Deformation Control
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Solution Overview
Problem
Existing snap cages for ball bearings deform radially due to centrifugal force at high speed rotation, leading to contact with other components and potential damage, while attempts to reduce weight for lower centrifugal force compromise rigidity and increase stress.
Innovation Solution
A snap cage design featuring a bar portion with a concave curved surface connecting to the main portion, lightened portions for weight reduction, and a thicker bottom thickness to enhance rigidity, reducing deformation and contact with other components by optimizing the radial thickness and pocket design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If the cage is made thinner at the bottom portion of the pocket to reduce weight, then centrifugal force is reduced, but the stress of the cage increases and deformation of the claw portion increases
Solution Approach 1:
The invention applies different thicknesses to different portions of the cage. The bottom portion of the pocket has a first thickness, while the bar portion has a second thickness that is thinner than the first. This local differentiation allows weight reduction in non-critical areas while maintaining sufficient strength in load-bearing areas, resolving the contradiction between weight reduction and stress resistance.
2Weight of moving object
If the cage is made thinner at the bottom portion of the pocket to reduce weight, then centrifugal force is reduced, but deformation of the claw portion increases
Solution Approach 1:
By making the bottom portion of the pocket thicker than the bar portion, the invention locally concentrates material where it is needed to support the claw portion against centrifugal deformation. This resolves the contradiction by reducing overall weight while preventing claw portion deformation through strategic material placement.
3Weight of moving object
If a through hole is formed in the base portion to reduce weight, then centrifugal force is reduced, but the rigidity of the base portion is reduced
Solution Approach 1:
Instead of forming a through hole that would compromise overall rigidity, the invention selectively removes material only from the bar portion while maintaining the full thickness of the bottom portion of the pocket. This local material removal reduces weight and centrifugal force without significantly affecting the rigidity of the base portion, as the critical load-bearing area remains intact.
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 design effectively suppresses deformation and contact with other components at high speed rotation by ensuring rigidity and reducing centrifugal force through weight reduction, maintaining structural integrity and preventing damage.
Implementation Method 1
the cage 100 comes into contact with other components such as the outer ring 5 and the shield plates 7, 7, and the cage 100 may be worn or damaged... centrifugal force at high speed rotation is reduced by reducing the weight of the axial portion
Implementation Method 2
an outer circumferential surface of the bar portion on the tip portion side and the outer circumferential surface of the main portion are connected by a concave curved surface
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A bar portion (12) includes a pair of claw portions, and is formed so that an outer circumferential surface on a tip portion side is located on an inner diameter side with respect to an outer circumferential surface of a main portion (11). On an inner diameter side of a cage (10), a plurality of lightened portions obtained by notching in an axial direction from an axial side surface of the main portion (11) to the respective bar portions (12) are formed separately at positions of the respective bar portions (12) in a circumferential direction. Each lighting portion (20) is formed separately from a surface of a pocket (13) and an axially outer surface of the bar portion (12) formed between a pair of claw portions (14). When an axial dimension of a wall portion (22) formed between an axially outer surface of the bar portion (12) and an inner wall surface of the lightened portion (20) is T1 and an axial dimension of the main portion (11) on a bottom portion of the pocket (13) is T2, T2 > T1 is satisfied. Accordingly, contact with other components hardly occurs even in a case in which deformation occurs due to centrifugal force at high speed rotation, and it is possible to suppress deformation at high speed rotation by ensuring rigidity of a predetermined portion while reducing the centrifugal force at high speed rotation due to weight reduction.