Axial Clamping for Bearing Ring Machining

Solution Overview

Problem

Existing methods for machining bearing rings often result in roundness defects and unacceptable distortions in the raceways due to radial clamping, which affects machining accuracy.

Innovation Solution

An apparatus that axially clamps a bearing ring at its opposite end surfaces, using a centering sleeve and locking levers to rotate the ring about its central axis, minimizing radial stresses and ensuring precise machining of raceways.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If radial jaws of a chuck are used to clamp the bearing ring radially, then the ring can be held and rotated for machining, but roundness defects and distortions occur in the raceways

Engineering Contradiction:

Improveroundness of racewaysVSAvoidradial clamping-induced deformations

Core Design Contradiction:

Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent inverts the conventional clamping approach by using axial clamping instead of radial clamping. The bearing ring is clamped axially between a support surface and a clamping surface, rather than being gripped radially by jaws. This inversion of the clamping direction eliminates the radial stresses that cause roundness defects while still providing sufficient holding force for machining operations.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the clamping parameter from radial force to axial force. By applying clamping force in the axial direction rather than the radial direction, the machining process avoids inducing radial stresses that lead to roundness defects. The axial clamping force is sufficient to hold the ring during rotation without causing the harmful radial deformations associated with conventional jaw chucks.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If radial clamping is applied to hold the bearing ring, then the ring can be secured for machining, but machining accuracy deteriorates due to induced stresses

Engineering Contradiction:

Improveholding stabilityVSAvoidmachining accuracy

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent inverts the conventional clamping approach by using axial clamping instead of radial clamping. The bearing ring is clamped axially between a support surface and a clamping surface, rather than being gripped radially by jaws. This inversion of the clamping direction eliminates the radial stresses that cause roundness defects while still providing sufficient holding force for machining operations.

Inventive Principle:

Principle #13The other way round (Inversion)

3Ease of operation

If conventional radial jaw chucks are used, then the bearing ring can be clamped and rotated, but the device complexity increases due to multiple radial jaws

Engineering Contradiction:

Improvering retention and rotationVSAvoidnumber of clamping components

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent extracts the essential function of holding and rotating the bearing ring from the complex multi-jaw chuck system. By using a simple axial clamping mechanism with a support surface and clamping surface, the device achieves the same retention and rotation functions with significantly reduced complexity. The radial jaws and their associated actuation mechanisms are eliminated entirely.

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentEP2811190B1Apparatus for machining a bearing ring

Publication Date: 2016.01.20 AB SKF SKF PATENT DEPARTMENT

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AI summary

An apparatus for machining a bearing ring (40) defining a central axis of rotation (x) and having an axially extending internal cavity (41) with one or more raceways (42) to be machined, and two opposite end surfaces (45, 46) which extend transversely to the axis of rotation (x) and are located at two respective opposite axial ends of the ring; the ring is retained axially clamped at the two opposite end surfaces (45, 46) and driven for rotation about the axis (x) to machine the raceway(s).