Synthetic Resin Bearing Retainer with Micro-Textured Guide Surfaces
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Solution Overview
Problem
Current rolling bearing retainers face issues with durability and productivity due to burr formation, which damages counter members and shortens service life, especially under severe conditions like machine tool spindle applications, and existing solutions do not adequately address the specific surface shape requirements or chamfered portions.
Innovation Solution
A synthetic resin rolling bearing retainer with guided portions having specific surface properties, including a chamfered portion and groove, and a parting line to prevent burr formation, combined with an amorphous surface layer and injection molding techniques to maintain micro concave-convex shape integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a phenol resin retainer is used to improve durability and sliding wear resistance, then the retainer exhibits excellent durability, but the strength is low, dimension stability is poor due to water absorption expansion, and productivity is low requiring cutting processing
Solution Approach 1:
The patent changes the material parameter from phenol resin to synthetic resin (such as polyamide resin), which fundamentally alters the material properties to achieve both high strength and excellent sliding wear resistance, eliminating the need for post-molding cutting processing and enabling mass production while maintaining durability
Solution Approach 2:
The patent employs composite material structure by combining synthetic resin base material with surface treatment (micro concave-convex shape formation) to achieve both bulk material strength and surface lubricating properties, resolving the contradiction between durability and productivity
2Productivity
If a synthetic resin retainer manufactured by injection molding is used to improve productivity, then high productivity is achieved, but the lubricating property of sliding parts is lowered and service life is shortened due to wear under severe conditions
Solution Approach 1:
The patent applies preliminary action by forming the micro concave-convex shape on the sliding surface during the injection molding process itself, before the retainer is installed and used. This preliminary surface treatment ensures excellent lubricating properties from the start, enabling both high productivity and long service life under severe conditions
Solution Approach 2:
The patent applies local quality by creating micro concave-convex structures specifically on the sliding surfaces (guided portions) while maintaining the overall integrity of the synthetic resin retainer. This localized surface modification provides excellent lubricating properties at critical contact areas without compromising the bulk material strength and productivity benefits
3Object-generated harmful factors
If barrel processing is performed to remove burrs from the retainer surface, then burrs are removed, but the micro concave-convex shape is also removed, so improvements on lubricating property and durability cannot be achieved
Solution Approach 1:
The patent applies preliminary action by forming the micro concave-convex shape during injection molding before any burr removal operations. By establishing the lubricating surface structure in advance, the subsequent burr removal process can be performed without compromising the essential micro concave-convex features, thus maintaining both burr-free surfaces and excellent lubricating properties
Solution Approach 2:
The patent segments the retainer surface into distinct functional zones: the guided portions with micro concave-convex shapes for lubrication, and other areas where burrs may form. This segmentation allows selective surface treatment and burr removal that preserves the critical lubricating micro structures while eliminating harmful burrs
4Ease of operation
If the retainer is designed with guided portions for smooth rotation, then smooth operation is achieved, but burrs form at the guided portions and chamfered portions, damaging counter members and shortening service life
Solution Approach 1:
The patent applies local quality by providing micro concave-convex shapes specifically on the guided portions that require smooth rotation. This localized surface treatment reduces friction and prevents burr formation at critical sliding areas, maintaining smooth operation while eliminating harmful burrs that would otherwise damage counter members
Solution Approach 2:
The patent applies preliminary action by forming the micro concave-convex shapes on guided portions and chamfered portions during the injection molding process, before the retainer is assembled and subjected to operational stresses. This preliminary surface treatment prevents burr formation from the outset, ensuring smooth rotation and preventing damage to counter members
Data Source
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AI summary
This rolling bearing retainer is a synthetic resin retainer disposed between the inner ring and the outer ring of a rolling bearing, wherein a plurality of sections to be guided are provided along the circumferential direction to protrude radially outward from the outer diameter surface. Each of the sections to be guided is provided with a guide surface which can be in sliding contact with the outer ring, a chamfered section formed on an edge portion of the guide surface, and a groove section formed in a portion of the guide surface in the axial direction. The guide surface 27 and the chamfered section have surface properties in which the arithmetic average roughness Ra is 1.0-9.8 µm and the maximum height Rt is 10.1-102.9 µm. A parting line PL is provided radially inside the guide surface.