Compact Oldham Floating Reamer Holder for Self-Centering Alignment

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Solution Overview

Problem

Existing floating reamer holders face issues with increased overhang and bending moments due to their design, which leads to wear and early breakage, and require recalibration with each reamer replacement, while also being costly and complex in production.

Innovation Solution

A compact Oldham-type floating reamer holder with a central protrusion and annular elastic element, including an annular wave spring, that allows for angular misalignment, parallel misalignment, and axial translation, while ensuring accurate centering in a non-operative position and reducing shear forces and axial displacement during machining.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a floating reamer holder design is used to accommodate misalignment, then the reamer can handle angular and parallel misalignment with the hole axis, but the overall overhang of the tool increases leading to larger bending moments

Engineering Contradiction:
Improvemisalignment accommodationVSAvoidbending moment
Core Design Contradiction:
Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The floating member is divided into two halves by a virtual plane, with each half located in respective female recesses in the holder and reamer portions. This segmentation allows the floating member to accommodate misalignment while maintaining a compact structure that reduces overhang and bending moments.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The floating member is nested within the holder and reamer portions, with each half positioned in its respective recess. This nested arrangement allows the floating mechanism to be compact, reducing the overall overhang of the tool while still providing misalignment accommodation capabilities.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Adaptability or versatility

If a complicated floating reamer holder design with many parts and pins is used, then the floating mechanism can be achieved, but the axial length of the holder increases and production costs increase

Engineering Contradiction:
Improvefloating mechanismVSAvoidnumber of parts
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The floating member is integrated as a single component that combines the functions of multiple separate parts. By merging the floating mechanism into one piece with two halves positioned in recesses, the design eliminates the need for multiple pins and separate components, reducing both axial length and production costs.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The floating member serves multiple functions simultaneously: it accommodates angular misalignment, parallel misalignment, and axial translation, while also transferring torque between the holder and reamer portions. This multi-functionality eliminates the need for separate components for each function, reducing overall complexity.

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

3Power

If an in-line engagement arrangement between the floating member and holder/reamer portions is used, then torque can be transferred, but the floating member is exposed to great shear forces leading to wear and early breakage

Engineering Contradiction:
Improvetorque transferVSAvoidwear resistance
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The floating member is positioned offset from the axial centerline, with each half located in its respective recess rather than in an in-line arrangement. This dimensional change in positioning allows torque transfer while reducing the shear forces experienced by the floating member, as the load is distributed more favorably across the structure.

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

4Adaptability or versatility

If a ball and coiled spring centering mechanism is used, then angular misalignment can be enabled, but the driven member requires manual tightening and recalibration with each reamer replacement

Engineering Contradiction:
Improveangular misalignmentVSAvoidcentering accuracy
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The floating member automatically centers itself relative to the holder and reamer portions through its geometric configuration and the constraints provided by the recesses. This self-centering mechanism eliminates the need for manual tightening or recalibration with each reamer replacement, as the floating member naturally finds its correct position during assembly.

Inventive Principle:
Principle #25Self-service

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

The solution provides a stable, cost-effective, and compact reamer holder that maintains accurate alignment and reduces wear, enabling high machining speeds and improved workpiece surface quality by minimizing unwanted imperfections and eliminating the need for recalibration during reamer replacement.

Implementation Method 1

an annular elastic element at least partially overlapping the reamer portion in the axial direction and biasing the reamer portion in the axially forward direction, the annular elastic element comprising an annular-shaped wave spring

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3325198B1Self-centering compact floating reamer holder
Publication Date: 2021.03.31 ISCAR LTD
  • EP3325198B1 patent drawingFigure 1~2
  • EP3325198B1 patent drawingFigure 3
  • EP3325198B1 patent drawingFigure 4~5

AI summary

A compact oldham-type floating reamer holder with holder and reamer portions which transfer torque therebetween via a floating member. The floating reamer holder includes an elastic element which axially biases the holder and reamer portions. In an operative position, the floating reamer holder is configured to automatically enable angular misalignment, parallel misalignment and axial translation between the holder and reamer portion axes. In a non-operative position, the reamer portion axis is co-aligned with the holder portion axis. And the elastic element at least partially overlaps the reamer portion.