Concentric Hydraulic Expansion Chuck for Balance and Coolant Feed

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Solution Overview

Problem

Hydraulic expansion chucks experience imbalance due to the eccentric arrangement of their pressure-generating devices, which complicates balancing and restricts centric coolant supply, particularly in minimum lubrication quantity technology where axial cooling is crucial.

Innovation Solution

The hydraulic expansion chuck features a ring-shaped piston and pressure-generating device arranged concentrically around the central axis, allowing for uniform mass distribution and enabling axially centric cooling lubricant supply by utilizing the central area for the cooling lubricant device, thus reducing imbalance and facilitating balanced operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the pressure-generating device is arranged eccentrically in the base body, then the clamping function is achieved, but the mass distribution becomes uneven leading to imbalance during operation

Engineering Contradiction:
Improveclamping functionVSAvoidmass distribution uniformity
Core Design Contradiction:
Ease of operationVSStability of the object's composition

Solution Approach 1:

The patent applies asymmetry in reverse - it deliberately chooses a symmetric (concentric) arrangement for the pressure-generating device around the central axis, contrary to the conventional asymmetric (eccentric) arrangement. This symmetric placement ensures uniform mass distribution and eliminates imbalance during rotation, while still achieving the required clamping function through the hydraulic pressure system.

Inventive Principle:
Principle #4Asymmetry

2Stability of the object's composition

If the pressure-generating device is arranged concentrically to reduce imbalance, then the mass distribution becomes uniform, but the central area is occupied preventing axially centric coolant supply

Engineering Contradiction:
Improvemass distribution uniformityVSAvoidcoolant supply capability
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The patent resolves the spatial conflict by transitioning from a two-dimensional planar arrangement to a three-dimensional configuration. The pressure-generating device is arranged concentrically in the radial dimension around the central axis, while the coolant supply channel is positioned in the axial dimension, extending through the hollow shank. This dimensional separation allows both functions to coexist without interference - the concentric pressure device reduces imbalance while the axial coolant channel enables centric cooling lubricant supply.

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

3Stability of the object's composition

If the central area of the base body is occupied by the pressure-generating device, then imbalance is reduced, but the coolant supply path is blocked

Engineering Contradiction:
Improvebalance qualityVSAvoidcoolant supply path
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent implements a nested configuration where the coolant supply channel is positioned within the hollow shank structure, and the pressure-generating device is arranged concentrically around the central axis within the base body. This nesting allows the coolant channel to pass through the central hollow area without interfering with the concentric pressure device, enabling both functions to operate independently while sharing the same spatial envelope.

Inventive Principle:
Principle #7Nested doll (Nesting)

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

This design significantly reduces imbalance and allows for efficient, centric coolant supply to the shank tool, enhancing the hydraulic expansion chuck's performance and applicability in MQL technology.

Implementation Method 1

The at least one pressure chamber can be pressurized with fluid pressure

Methodology Applied
Scientific EffectFluid pressure: Pressure Increase

Implementation Method 2

clamping the shank tool received in the central receiving opening by friction

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 3

an elastically compliant expansion wall separating the at least one pressure chamber from the receiving opening

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3815822A1Hydraulic expansion chuck
Publication Date: 2021.05.05 GUEHRING KG
  • EP3815822A1 patent drawingFigure 1
  • EP3815822A1 patent drawingFigure 2~3
  • EP3815822A1 patent drawingFigure 4a~4b

AI summary

The invention relates to a hydraulic expansion chuck with a base body extending along a rotary or longitudinal axis, comprising a clamping element for receiving and clamping a shank tool and a shank element with a hollow shank for directly or indirectly coupling the hydraulic expansion chuck to a module of a modular tool system or to a machine spindle. The clamping element has a central receiving opening and, around the receiving opening, at least one pressure chamber that can be pressurized with fluid, which is separated from the receiving opening by an elastically compliant expansion wall and connected to a pressure chamber via a pressure channel system. Furthermore, a pressure generation device for pressurizing the pressure chamber is arranged in the base body.According to the invention, the pressure generating device comprises an annular piston which is arranged axially displaceably in an annular piston chamber arranged concentrically to the receiving opening, which is connected to the pressure chamber on the clamping part side and opens into the hollow shaft on the shaft part side, and which can be actuated through the hollow shaft.