Ball Bearing Cage Web Structure Without Snap-Fit Retention

Solution Overview

Problem

High-speed ball bearings with plastics-material snap-fit cages face inaccuracies and increased production costs due to the complexities of injection-molding, leading to performance deficiencies.

Innovation Solution

A ball bearing cage design with axially protruding webs that cover the distal shoulder of the ball bearing races, eliminating the need for snap-fit mechanisms and allowing for a simpler injection-molding process, ensuring precise alignment and stability without snap-fitting, and incorporating a guide portion for retention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If snap-fit mechanisms are used in ball bearing cages, then retention of balls is improved, but manufacturing precision and production costs deteriorate due to injection-molding complexities

Engineering Contradiction:

Improveretention of ballsVSAvoidaccuracy of ball bearing cage

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent removes the snap-fit mechanism from the ball bearing cage design. Instead of using protruding cage elements that snap onto the races, the cage is designed with a simplified structure that relies on proper dimensional matching and interference fit during assembly, eliminating the complex snap-fit features that cause manufacturing inaccuracies.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Rather than having the cage actively retain balls through snap-fit protrusions, the design inverts the approach by having the cage passively held in position through precise dimensional relationships with the races during assembly, allowing the assembly process itself to provide retention rather than relying on complex cage features.

Inventive Principle:

Principle #13The other way round (Inversion)

2Reliability

If snap-fit mechanisms are used in ball bearing cages, then retention of balls is improved, but production costs increase due to manufacturing complexities

Engineering Contradiction:

Improveretention of ballsVSAvoidproduction cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent removes the snap-fit mechanism from the ball bearing cage design. Instead of using protruding cage elements that snap onto the races, the cage is designed with a simplified structure that relies on proper dimensional matching and interference fit during assembly, eliminating the complex snap-fit features that cause manufacturing inaccuracies.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Rather than having the cage actively retain balls through snap-fit protrusions, the design inverts the approach by having the cage passively held in position through precise dimensional relationships with the races during assembly, allowing the assembly process itself to provide retention rather than relying on complex cage features.

Inventive Principle:

Principle #13The other way round (Inversion)

3Reliability

If complex injection-molding processes are used for ball bearing cages, then retention mechanisms are improved, but manufacturing precision deteriorates

Engineering Contradiction:

Improveretention mechanismVSAvoidaccuracy of cage dimensions

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent removes the snap-fit mechanism from the ball bearing cage design. Instead of using protruding cage elements that snap onto the races, the cage is designed with a simplified structure that relies on proper dimensional matching and interference fit during assembly, eliminating the complex snap-fit features that cause manufacturing inaccuracies.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the dimensional parameters of the cage components to enable direct assembly without snap-fit mechanisms. By carefully selecting the interference fit dimensions and tolerance ranges between the cage and races, the design achieves reliable retention through simplified geometry that is more amenable to precise injection-molding.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11649856B2Ball bearing cage and ball bearing

Publication Date: 2023.05.16 GEBR REINFURT

AI summary

A ball bearing cage has a radially encircling, annular body, on which in the circumferential direction, substantially evenly distributed, axially projecting webs having a predefinable axial length are arranged. The webs form a plurality of axially open ball pockets on one side for accommodating a corresponding number of balls having a predefinable ball diameter. At least for one web, a guide section is formed to bring same into an engagement with a running groove of a ball bearing ring. The axial length of the webs corresponds to at least the ball diameter. There is also described a ball bearing having such a ball bearing cage.