Crown Ball Bearing Retainer Structure for High-Speed Deformation Control
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Solution Overview
Problem
Existing crown cages for ball bearings face issues with deformation, stress, and moldability during high-speed rotation, particularly in small-sized bearings, due to design limitations and material flow constraints.
Innovation Solution
A crown cage design featuring pillar portions with claw ends, a wider pocket outer diameter, and convex portions on the main portion bottom surface, made from reinforced resin materials, which reduces weight and stress while maintaining good moldability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If a hole communicating with the recessed area of the axial portion and penetrating in the axial direction is formed in the base portion to reduce material amount and suppress radial deformation, then the mass is reduced and radial deformation is suppressed, but the periphery of the hole becomes too thin and strength is reduced
Solution Approach 1:
The patent transitions from axial penetration (one-dimensional hole through base portion) to radial extension (two-dimensional rib structure extending from base portion outer diameter surface). This dimensional change allows material removal for weight reduction while maintaining structural integrity through the rib's radial configuration rather than creating thin-walled holes that compromise strength
2Reliability
If the cage structure is modified to reduce deformation and stress during high-speed rotation, then fatigue failure is suppressed, but the moldability and resin flow during injection molding may be affected
Solution Approach 1:
The cage is segmented into functionally distinct components: the base portion for structural support and moldability, the axial portion for ball engagement, and the rib for targeted reinforcement. This segmentation allows each part to be optimized independently - the base portion maintains good moldability while the rib provides the necessary reinforcement for fatigue resistance during high-speed rotation
Solution Approach 2:
Reinforcement is applied locally through the rib structure extending from the base portion outer diameter surface, rather than uniformly throughout the entire cage. This localized reinforcement provides the necessary strength for fatigue resistance in critical areas while maintaining overall light weight and not interfering with the injection molding process
3Object-affected harmful factors
If the cage is designed to prevent contact with outer ring and seal by suppressing deformation, then wear and heat generation are reduced, but the structural complexity increases
Solution Approach 1:
The reinforcement function is extracted as a separate rib component extending from the base portion, rather than integrating reinforcement throughout the entire cage structure. This extraction creates a simple, clean design where the rib specifically addresses the contact prevention function without adding unnecessary complexity to other parts of the cage
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 stress during high-speed rotation, preventing wear, vibration, and heat generation, while ensuring efficient resin flow and moldability.
Implementation Method 1
the stress may act on the cage 100 due to the centrifugal force during the high-speed rotation, and the cage 100 may be deformed toward an outer diameter side
Data Source
AI summary
A crown cage for a ball bearing includes an annular main portion, pillar portions protruding in an axial direction at predetermined intervals in a circumferential direction from the main portion, and a pocket formed between the adjacent pillar portions and having a spherical concave surface capable of holding a ball. The pillar portion includes a pair of claw portions having tip end portions arranged at intervals therebetween and a connection portion connecting the pair of claw portions. An inlet portion having a width shorter than a diameter of the ball and for inserting the ball is provided between the tip end portions of the two adjacent claw portions constituting the pocket. A distance from an outer circumferential surface of the pocket to a center of the crown cage for a ball bearing is larger than a distance from an outer circumferential surface of the pillar portion to the center.