Conical Roller Bearing Cage Structure for Easier Roller Assembly

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Solution Overview

Problem

Existing roller bearing cages face challenges in assembly efficiency, maintenance performance, and strength due to difficulties in inserting and removing rollers, as well as increased manufacturing costs and precision issues, particularly with conical roller bearings requiring complex deformation processes and large molds.

Innovation Solution

A roller bearing cage design with pocket holes having center guide portions and end portions positioned radially outside the pitch circle diameter, featuring retaining projections and relief portions that allow rollers to be inserted and removed inclined, eliminating the need for bottom-enlarging and swaging processes, and maintaining column width for strength and moldability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If retaining projections are positioned at the center of columns that underwent step-forming process, then roller retention is achieved, but the intervals between opposite retainers vary largely and diameters of circumscribing circle vary, making it difficult to attach outer ring

Engineering Contradiction:
Improveroller retentionVSAvoidinterval consistency
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The retaining projections are repositioned from the center of columns to diagonal corners of the pocket holes, changing the spatial dimension of retention mechanism. This dimensional shift allows retainers to be positioned at consistent radial distances from the cage center, eliminating variations in circumscribing circle diameters while maintaining effective roller retention through diagonal corner positioning.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Ease of operation

If columns are positioned to have central annular portions at radially outside of pitch circle diameter, then roller guidance is improved, but column width is reduced causing strength and moldability problems

Engineering Contradiction:
Improveroller guidanceVSAvoidcolumn strength
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The column structure is segmented into distinct functional portions: end portions that maintain full width for structural strength and moldability, and central guide portions that provide roller guidance. This segmentation allows each portion to be optimized independently - the end portions retain sufficient width for strength while the central guide portions are positioned to provide effective roller guidance without compromising overall column integrity.

Inventive Principle:
Principle #1Segmentation

3Manufacturing precision

If bottom-enlarging process and swaging process are performed on cage columns, then cage shape is restored and precision is improved, but manufacturing cost increases and large pressing machines are required

Engineering Contradiction:
Improvecage precisionVSAvoidmanufacturing process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The cage columns are pre-formed with the correct final shape and dimensions during the initial pressing process, eliminating the need for subsequent bottom-enlarging and swaging operations. The pocket holes are positioned and sized correctly from the start, allowing direct assembly without restorative deformation processes, thereby simplifying manufacturing and reducing equipment requirements.

Inventive Principle:
Principle #10Preliminary action

4Ease of operation

If pocket holes are formed with retaining projections at diagonal corners, then rollers can be inserted from radially outside, but relief portions must be provided to avoid interference

Engineering Contradiction:
Improveroller insertionVSAvoidpocket hole structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

Relief portions are provided locally at specific corners of the pocket holes where retaining projections are positioned, rather than modifying the entire pocket hole structure. This localized modification allows rollers to be inserted from the radially outside direction by providing clearance only where interference would occur, maintaining the overall simplicity of the pocket hole design while enabling improved assembly operation.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3770453B1Roller bearing cage
Publication Date: 2023.09.13 NAKANISHI METAL WORKS CO LTD
  • EP3770453B1 patent drawingFigure 1~2
  • EP3770453B1 patent drawingFigure 3~4
  • EP3770453B1 patent drawingFigure 5~6

AI summary

[Object] A roller bearing cage is provided which is excellent in assembly work efficiency and maintenance performance, which does not develop a problem regarding strength, etc., due to width reduction of a column, and which can eliminate the necessity of bottom-enlarging process or swaging process when the roller bearing cage is a conical roller bearing. [Solution] A conical roller bearing cage 1 has a large-diameter ring 2 and a small-diameter ring 3 which are connected via a plurality of columns 4. Each of the columns 4 is formed of a center guide portion 5, a large-diameter-side end portion 6 connected to the large-diameter ring 2, and a small-diameter-side end portion 7 connected to the small-diameter ring 3. The center guide portion 5 is located on the radially outside of a pitch circle diameter of conical rollers 15, and a pair of the end portions 6, 7 are located in the radially outside of the center guide section 5. Retaining projections 6A, 7A for retaining the conical rollers 15 with the conical rollers 15 being attached to an inner ring 11, are provided at the end portions 6, 7 of the column 4 so as to be diagonally positioned in a pocket hole P.