Angle Measuring Device Bearing Seal for Clean Room Contamination Control

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Solution Overview

Problem

Angle measuring devices used in clean room environments face challenges in maintaining air purity and preventing contamination, as existing systems are not effective in efficiently removing impurities and preventing the escape of wear particles.

Innovation Solution

The angle measuring device features a bearing with a non-contact seal and a fluid flow system that creates a significant difference in mass flows, ensuring that a larger mass flow of fluid is used to remove impurities while minimizing contamination by limiting the flow through the bearing gap, utilizing a roller bearing with a narrow gap and flow deflection to prevent particle escape.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a bearing with a bearing gap is used to allow rotation between component groups, then rotational movement is enabled, but impurities and wear particles can escape into the surrounding environment

Engineering Contradiction:
Improverotational movementVSAvoidwear particles escape
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The bearing seal is divided into multiple segments or elements arranged in sequence around the bearing gap. Each segment creates a localized flow deflection, and the combined effect of multiple segments provides enhanced sealing capability while maintaining rotational freedom.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A fluid (typically air or gas) is introduced as an intermediary substance that flows through the bearing gap in a controlled manner. This fluid creates a positive pressure barrier that prevents wear particles from escaping while allowing rotational movement to continue uninterrupted.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If suction is applied to remove impurities, then air purity is improved, but the flow through the bearing gap increases causing more wear particles to escape

Engineering Contradiction:
Improveair purityVSAvoidwear particles escape
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The sealing structure creates different flow conditions at different locations around the bearing gap. The seal elements are positioned and dimensioned to create localized flow deflections that specifically target the bearing gap region, while the overall suction field continues to remove impurities from the environment.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The seal geometry is designed with asymmetric features where the flow deflection angles and gap dimensions are optimized to create a pressure barrier against particle escape while maintaining permeability to allow the bulk fluid flow for impurity removal. The seal structure treats different directions of flow differently.

Inventive Principle:
Principle #4Asymmetry

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 configuration effectively maintains a clean environment by ensuring that impurities are removed and preventing wear particles from contaminating the surrounding area, ensuring the air purity and operational integrity of the device.

Implementation Method 1

a negative pressure can be applied to the connection device, so that a fluid surrounding the angle measuring device with a pressure flows through the angle measuring device for sucking off impurities

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 2

The non-contact seal can be designed, for example, as a narrow gap and/or as a flow deflection, in particular as a multiple flow deflection

Methodology Applied
Scientific EffectFlow deflection:

Data Source

PatentEP2329228B1Angle measuring device
Publication Date: 2013.07.31 DR JOHANNES HEIDENHAIN GMBH
  • EP2329228B1 patent drawingFigure 1
  • EP2329228B1 patent drawingFigure 2
  • EP2329228B1 patent drawingFigure 3

AI summary

The invention relates to an angle measuring device comprising a first component group (10) and a second component group (20), wherein the component groups (10, 20) are arranged so as to be able to rotate relative to each other through a bearing (11.1, 21, 23, 30). The first component group (10) comprises a housing (11) having a connection device (11.31) and a scanning device (12). The second component group (20) comprises a shaft (21), to which a code disk (22) is fastened, and a flow channel (21.1) having a directional component parallel to the axis (Z). The angle measuring device is configured in such a way that a negative pressure (p0) can be applied to the connection device (11.31) so that a fluid surrounding the angle measuring device at a pressure (P1) flows through the angle measuring device to suck away contaminants. At the applied negative pressure (p0), a first fluid mass flow (m1) flowing through the flow channel (21.1) is greater than a second mass flow (m2) flowing through the bearing gap (S).