Tool Holder Coupling Element for Misalignment and Vibration Control

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Solution Overview

Problem

Vibration phenomena occur at high speeds in tool holders and clamping devices due to misalignments between the drive shaft and spindle, affecting machining quality and tool service life.

Innovation Solution

A coupling device with a loose coupling element that compensates for misalignments between the drive shaft and spindle, providing minimal play and ensuring precise alignment, thereby reducing vibrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a rigid coupling between drive shaft and spindle is used, then torque transmission is efficient, but misalignments cause vibrations at high speeds

Engineering Contradiction:
Improvetorque transmission efficiencyVSAvoidvibrations
Core Design Contradiction:
PowerVSObject-affected harmful factors

Solution Approach 1:

The coupling element is designed with radial play that allows dynamic adjustment to misalignments between drive shaft and spindle, enabling the coupling to adapt its position while transmitting torque, thereby eliminating vibrations caused by rigid coupling at high speeds

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention introduces a specific radial play parameter (0.02mm to 0.08mm) between the coupling element and drive shaft, which allows the coupling to compensate for misalignments while maintaining sufficient torque transmission, resolving the contradiction between rigid torque transmission and vibration elimination

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If play is increased between driver and driver groove to compensate for misalignments, then coupling is easier, but torque transmission precision deteriorates

Engineering Contradiction:
Improvecoupling easeVSAvoidtorque transmission precision
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The invention optimizes the radial play parameter to a specific range (0.02mm to 0.08mm) that balances two requirements: sufficient play to accommodate misalignments and ensure easy coupling, while maintaining tight enough clearance to preserve torque transmission precision and minimize vibrations

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If minimal play is provided between driver and driver groove, then torque transmission is precise, but misalignments cause coupling difficulties

Engineering Contradiction:
Improvetorque transmission precisionVSAvoidcoupling difficulty
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The coupling element acts as an intermediary between the drive shaft and spindle, incorporating radial play that allows it to absorb misalignments while maintaining minimal play for precise torque transmission, thus facilitating easy coupling without sacrificing precision

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP1961515B2Coupling device and coupling element for a tool holder or workpiece clamps
Publication Date: 2021.07.14 ESA EPPINGER GMBH
  • EP1961515B2 patent drawingFigure 1
  • EP1961515B2 patent drawingFigure 2~3
  • EP1961515B2 patent drawingFigure 4~7

AI summary

The coupling device has a spindle (16) which is arranged coaxial to a drive shaft (19). The drive shaft and the spindle carry separated drive elements (24,26a) and a coupling element (27) is arranged between both the drive elements. The coupling element compensate a misalignment between the drive shaft and the spindle is coupled in form-fit manner with the drive elements of the drive shaft and the spindle. The coupling element is held on the drive shaft or the spindle in undetachable manner.