Collet Chuck Coupling for Fast Tool Changes and Concentricity

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Solution Overview

Problem

Collet chucks with roller bearings face difficulties in achieving reproducible concentricity due to sliding friction between the clamping nut and collet, and the unit of collet and clamping nut is often inseparable, making tool changes time-consuming and costly.

Innovation Solution

A collet chuck design featuring a multi-part clamping nut with a clamping ring and threaded section connected via a roller bearing, allowing for quick collet replacement without completely unscrewing the clamping nut from the chuck body, and incorporating positive-locking elements for precise alignment and sealing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the clamping nut and collet form a single unit, then the concentricity is improved, but the tool change time increases and the adaptability decreases

Engineering Contradiction:
ImproveconcentricityVSAvoidtool change time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The clamping nut is divided into two separate parts: a clamping ring that remains on the chuck body and a threaded section that can be removed. This segmentation allows the collet to be quickly detached by removing only the threaded section, while the clamping ring stays in place to maintain positioning accuracy and concentricity for the next collet installation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The clamping ring serves multiple functions: it provides a mounting interface on the chuck body, maintains the positioning relationship, and guides the collet during installation. This multi-functionality allows the same component to remain on the chuck body across multiple tool changes, reducing the need to replace entire assemblies and improving adaptability.

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

2Adaptability or versatility

If the clamping nut is completely unscrewed for collet replacement, then the adaptability is improved, but the thread wear increases and the productivity decreases

Engineering Contradiction:
Improvecollet replacement flexibilityVSAvoidtool change efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

By separating the clamping nut into a stationary clamping ring and a removable threaded section, the design allows the threaded section to be quickly detached and replaced without affecting the clamping ring. This eliminates the need to completely unscrew the entire clamping nut assembly, reducing thread wear on the chuck body and speeding up the tool change process.

Inventive Principle:
Principle #1Segmentation

3Ease of operation

If the clamping ring moves relative to the collet during tightening, then the ease of operation is improved, but the manufacturing precision deteriorates due to sliding friction

Engineering Contradiction:
Improvetightening operationVSAvoidconcentricity
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The design replaces the traditional sliding friction mechanism with a rolling bearing mechanism between the threaded section and the clamping ring. This substitution eliminates harmful sliding friction that would affect concentricity, while still allowing the threaded section to be easily tightened and loosened. The rolling bearing provides smooth operation without compromising positioning accuracy.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

Enables quick and precise tool changes with reduced thread wear, improved concentricity, and enhanced sealing, reducing the need for multiple collet and nut assemblies and minimizing operational time.

Implementation Method 1

The threaded section and the clamping ring are connected to one another in a movable fashion via a rolling bearing, such that when the clamping nut is tightened, no more sliding friction forces occur between the clamping nut and the collar of the collet

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3263251B1Collet, clamping nut, and collet chuck having special interaction between the collet and the clamping nut
Publication Date: 2023.01.11 HAIMER
  • EP3263251B1 patent drawingFigure 1
  • EP3263251B1 patent drawingFigure 2~3
  • EP3263251B1 patent drawingFigure 4~5

AI summary

A collet chuck (1) for clamping a tool shank, comprising a chuck body (2), a collet (3) and a multi-part clamping nut (4) consisting of a clamping ring (5) and a threaded section (6), which are rotatably connected to each other via rolling elements (22) and otherwise positively locked, characterized in that the clamping ring (5) and the collet (3) have positively locking coupling elements designed such that the collet (3) can be inserted into the collet receptacle (10) through the central opening of the clamping ring (5) held on the chuck body (2) facing away from the chuck body (2) by moving the coupling elements past each other, and then the coupling elements can be engaged with each other by rotating the clamping ring (5) relative to the collet (3).so that the clamping ring (3) can transmit the forces conveyed to it by the threaded section (6) during tightening via the coupling elements to the collet (3) and drive the collet (3) into the chuck body (2).