Barrel-Profile Milling Tool for Rolling Bearing Cage Pockets

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Solution Overview

Problem

The machining of comb cages for rolling bearings, particularly spherical roller bearings, is inefficient due to the need for multiple processing stages and lack of precise finishing in existing methods.

Innovation Solution

A milling tool with a barrel-shaped cutting edge configuration, featuring adjustable indexable cutting inserts on the end face and fixed cutting plates on the lateral surface, allows for efficient machining of the pocket bottom and wall in two stages, approximating the shape of barrel rollers, thereby reducing the need for post-processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional milling tools with flat cutting edges are used, then multiple machining processes are required to produce comb cages, but this increases production time and reduces efficiency

Engineering Contradiction:
Improveproduction efficiencyVSAvoidmachining time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The cutting tool is segmented into two distinct groups: cutting inserts on the end face for machining the pocket bottom, and cutting inserts on the lateral surface for machining the pocket wall. This segmentation allows simultaneous or sequential machining of different surfaces in a single setup, eliminating the need for multiple separate machining processes and reducing production time.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from traditional flat cutting edges to a three-dimensional barrel-shaped cutting edge configuration. The cutting edges are arranged on both the end face and lateral surface of the base body, utilizing multiple spatial dimensions to machine different surfaces of the comb cage simultaneously, thereby improving productivity and reducing machining time.

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

2Ease of manufacture

If traditional milling tools are used for comb cage machining, then multiple processing stages are required, but this increases device complexity and process steps

Engineering Contradiction:
Improveprocess simplicityVSAvoidnumber of machining processes
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The invention merges the functions of machining the pocket bottom and pocket wall into a single milling tool. The base body includes both end-face cutting inserts for the pocket bottom and lateral-surface cutting inserts for the pocket wall, combining multiple machining operations into one tool and one setup, thereby simplifying the manufacturing process.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The milling tool is designed with multi-functionality, where a single base body performs multiple machining tasks: the end face cutting inserts machine the pocket bottom, while the lateral surface cutting inserts machine the pocket wall. This universal tool eliminates the need for separate specialized tools for each surface, reducing process complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Manufacturing precision

If traditional cutting edge configurations are used, then precise finishing of the pocket wall is difficult to achieve, but using additional machining steps increases production time

Engineering Contradiction:
Improvegeometric precision of pocket wallVSAvoidmachining efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The invention applies local quality by providing different cutting insert configurations for different locations: the lateral surface cutting inserts are specifically designed with barrel-shaped cutting edges that match the curvature of the pocket wall, enabling precise finishing of the curved surface without requiring additional machining steps, thus maintaining high geometric precision while preserving productivity.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3969215B1Milling tool and method for producing a rolling bearing cage
Publication Date: 2025.01.08 SCHAEFFLER TECHNOLOGIES AG & CO KG
  • EP3969215B1 patent drawingFigure 1
  • EP3969215B1 patent drawingFigure 2

AI summary

A milling tool (1) comprises a main body (2) to which cutting inserts (3, 4) are fastened, which each have at least one cutting edge (5, 6). Collectively, the cutting edges (5, 6) describe a barrel shape, wherein a first group of cutting inserts (3) is arranged on an end face (7) of the main body (2) and a second group of cutting inserts (4) is arranged on a barrel-shaped curved lateral face (8) of the main body (2).