Orbital Forging Bearing Layout for Large Swing-Angle Hub Crimping

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Solution Overview

Problem

Conventional orbital forging devices are large and costly due to the need for a thrust sliding bearing with a partially spherical sliding surface, and the size and cost increase when setting the swing angle of the molding die to 15 degrees or more, which is required to suppress deformation and machining load in forming crimped portions for hub unit bearings.

Innovation Solution

The orbital forging device uses a rolling bearing with axial and radial load support, preventing movement toward the frame, allowing a larger swing angle of 15 to 30 degrees without the need for a thrust sliding bearing, and includes a detachable bearing holder to adjust the inclination angle, reducing device size and manufacturing cost.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a thrust sliding bearing with a partially spherical sliding surface is used to support the swinging shaft, then the device can maintain stability during orbital forging, but the device size and manufacturing cost increase significantly

Engineering Contradiction:
Improvestability during orbital forgingVSAvoiddevice size and manufacturing cost
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts and removes the thrust sliding bearing from the system. Instead of using a thrust sliding bearing with a partially spherical sliding surface to support the swinging shaft, the patent uses a simpler structure where the swinging shaft is supported by a bearing that only needs to support radial loads, thereby reducing device complexity and manufacturing cost while maintaining the necessary stability through the spherical seat mechanism

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention applies spheroidality by introducing a spherical seat (convex spherical surface) that engages with a corresponding concave spherical surface on the frame. This spherical engagement provides the necessary stability and guidance for the swinging shaft during orbital forging operations, replacing the need for a complex thrust sliding bearing while maintaining reliability

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Manufacturing precision

If the swing angle of the molding die is set to 15 degrees or more to suppress deformation and machining load, then the manufacturing precision of crimped portions improves, but the device size increases due to the thrust sliding bearing requirements

Engineering Contradiction:
Improvedeformation suppression of inner ringVSAvoiddevice size
Core Design Contradiction:
Manufacturing precisionVSLength of stationary object

Solution Approach 1:

By removing the thrust sliding bearing from the system, the invention eliminates the size constraint that previously limited the swing angle. This allows the molding die to be set at a swing angle of 15 degrees or more, which suppresses deformation of the inner ring and improves manufacturing precision of crimped portions without increasing device size

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The spherical seat mechanism provides stable support for larger swing angles. The convex spherical surface on the swinging shaft engages with the concave spherical surface on the frame, allowing the molding die to swing at 15 degrees or more while maintaining stability and precision, thereby achieving better deformation suppression without requiring a larger device

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Stability of the object's composition

If a thrust sliding bearing is assembled to prevent movement of the swinging shaft, then axial position stability is maintained, but the device becomes more complex and expensive

Engineering Contradiction:
Improveaxial position stabilityVSAvoidmanufacturing cost
Core Design Contradiction:
Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The invention extracts and eliminates the thrust sliding bearing from the system. The axial position stability previously provided by the thrust sliding bearing is achieved through alternative means, specifically through the bearing arrangement that supports the swinging shaft and the spherical seat mechanism, thereby reducing manufacturing cost and device complexity while maintaining stability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces a bearing as an intermediary element to support the swinging shaft. This bearing, combined with the spherical seat mechanism, provides the necessary axial position stability without requiring a thrust sliding bearing, thereby simplifying the device structure and reducing manufacturing cost

Inventive Principle:
Principle #24Intermediary (Mediator)

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 configuration enables the formation of crimped portions with suppressed inner ring deformation and reduced machining load, resulting in a compact and cost-effective orbital forging device capable of manufacturing hub unit bearings efficiently.

Implementation Method 1

a rolling bearing (28) which supports, between an outer ring (29) and an inner ring (30), an axial load acting on the end section on the other side in the axial direction of the swinging shaft (13)

Methodology Applied
Scientific EffectRolling bearing: Ball Bearing

Implementation Method 2

the molding die (15) rotates around its center axis (β) based on the friction force that acts on the contact portion thereof with the inner end section in the axial direction of the cylindrical section (8)

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 3

the inner end section in the axial direction of the cylindrical section (8) is plastically deformed outward in the radial direction so as to form a crimped portion (9)

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Data Source

PatentEP3590624B1Rotary forge device, rotary forging method, method for manufacturing hub unit bearing using rotary forging method, and vehicle manufacturing method
Publication Date: 2023.06.28 NSK LTD
  • EP3590624B1 patent drawingFigure 1
  • EP3590624B1 patent drawingFigure 2A~2B
  • EP3590624B1 patent drawingFigure 3A~3B

AI summary

Provided is construction which is able to downsize an orbital forging device comprising a spherical seat with shaft that swings and rotates with a molding die. The end section on the other side in the axial direction of the swinging shaft 13 is supported with respect to the driving mechanism 17 in a state where the movement toward one side in the axial direction (lower side) is prevented, and a member for preventing the swinging shaft 13 from moving toward the one side in the axial direction with respect to the frame 10 is not assembled in a section which is located between the convex spherical seat 14 and the driving mechanism 17 in the axial direction of the swinging shaft 13.