Wheel Roller Bearing Solid Columnar Caulking

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Solution Overview

Problem

Conventional methods for manufacturing wheel rolling bearing devices require complex molds and equipment, incur high costs and time, and result in caulked portions with low rigidity due to their hollow center, which complicates the assembly and securing of inner rings.

Innovation Solution

A method involving a simpler mold to form a solid columnar caulked portion by caulking, eliminating the need for complex cylindrical shapes and internal machining, thereby enhancing the rigidity of the caulked portion and reducing manufacturing time and costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a cylindrical portion is formed by forward extrusion process in cold forging, then the inner ring can be secured by caulking, but the mold becomes complicated

Engineering Contradiction:
Improvesecuring of inner ringVSAvoidmold complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts the unnecessary cylindrical hollow shape from the shaft end portion, retaining only the essential function of securing the inner ring through caulking. By removing the complex cylindrical molding requirement and keeping only the basic columnar form, the mold complexity is reduced while the securing function remains effective.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of forming a hollow cylindrical shape and then caulking it, the invention inverts the approach by directly forming a solid columnar shape and caulking it. This reversal eliminates the need for complex hollow molding while achieving the same securing purpose through the caulked portion.

Inventive Principle:
Principle #13The other way round (Inversion)

2Reliability

If a cylindrical portion is formed by turning, then the inner ring can be secured by caulking, but equipment, time, and cost are incurred

Engineering Contradiction:
Improvesecuring of inner ringVSAvoidmanufacturing efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The invention extracts and eliminates the unnecessary turning operation and cylindrical hollow shape formation. By directly forming a solid columnar shape through simpler processes, the manufacturing time, equipment requirements, and costs are reduced while the inner ring securing function is maintained through caulking.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces expensive and time-consuming turning operations with simpler, more cost-effective forming processes. The solid columnar shape can be formed more economically without requiring complex turning equipment or extensive machining time, thereby improving manufacturing efficiency.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Reliability

If a cylindrical portion is caulked outward to form a caulked portion, then the inner ring is secured, but the center portion becomes hollow reducing rigidity

Engineering Contradiction:
Improvesecuring of inner ringVSAvoidrigidity of caulked portion
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The invention inverts the conventional approach by starting with a solid columnar shape instead of a hollow cylindrical shape. By caulking the solid shape outward, the caulked portion maintains its solid structure throughout, eliminating the hollow center and thereby improving rigidity while still securing the inner ring effectively.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The invention creates a composite structure where the solid columnar shaft end portion and the caulked material form an integrated solid mass. This composite approach ensures that the entire caulked portion remains solid rather than hollow, enhancing the rigidity and strength of the securing structure.

Inventive Principle:
Principle #40Composite materials

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

This approach allows for more efficient and cost-effective production of wheel rolling bearing devices with improved rigidity of the caulked portion, as the solid columnar shape eliminates the need for complex mold formation and internal machining, leading to enhanced structural integrity and reduced production time.

Implementation Method 1

the shaft end portion 15 is caulked outward in a radial direction thereby to form a caulked portion 17

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Data Source

PatentEP2684626B1Manufacturing method for wheel roller bearing device
Publication Date: 2019.06.05 JTEKT CORP
  • EP2684626B1 patent drawingFigure 1
  • EP2684626B1 patent drawingFigure 2(A)~2(B)
  • EP2684626B1 patent drawingFigure 3

AI summary

[Problem] To provide a method of manufacturing a wheel rolling bearing device capable of manufacturing the wheel rolling bearing device using a simpler mold with higher efficiency, and capable of further enhancing rigidity of a caulked portion for securing an inner ring which is fitted to one end of a shaft portion. [Means for Solution] An outer ring 45 and rolling elements 50 are fitted to a shaft member 1 of the wheel rolling bearing device from a shaft end portion 15, and further, an inner ring 42 and rolling elements 51 are fitted to the shaft member 1. Then, the shaft end portion 15 is caulked to form a caulked portion 17, and thus, the inner ring 42 is secured. On this occasion, the shaft end portion 15 to be caulked has a solid columnar shape. A caulking jig P is pressed against the shaft end portion 15, and oscillated while the caulking jig P is pressed in a direction toward one end of a shaft portion 10, thereby to spread by caulking a face 15M to be caulked in the shaft portion having the solid columnar shape.