Internal Gear Runout Measurement for Deep Shaft Recesses

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Solution Overview

Problem

Current methods for measuring the concentricity of internal toothing in shafts, especially those with small diameters or deep recesses, are complex, time-consuming, and inaccurate, particularly when components are wetted with machining media, and require costly laser technology or coordinate measuring machines.

Innovation Solution

A closure measurement device comprising a spindle unit, adjusting element, and measuring unit, with a teaching gear and spindle holder, allowing for precise measurement of internal toothing concentricity without direct contact, enabling measurement in deep recesses and small diameters, and adaptable for use with components wetted by machining media.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Difficulty of detecting and measuring

If laser technology is used to measure concentricity of internal toothing in deep recesses, then measurement capability is improved, but measurement time and cost increase significantly

Engineering Contradiction:
Improvemeasurement capabilityVSAvoidmeasurement time
Core Design Contradiction:
Difficulty of detecting and measuringVSLoss of time

Solution Approach 1:

The patent replaces complex laser technology with a mechanical measurement system consisting of a teaching gear, spindle unit, and measuring encoder. The teaching gear engages directly with the internal toothing, and the spindle unit converts rotational movement into measurable linear displacement, providing a simpler mechanical alternative to optical laser measurement methods.

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

Solution Approach 2:

The teaching gear acts as an intermediary element that bridges the measurement system and the internal toothing. It engages with the internal gear teeth and transfers their movement to the spindle unit, enabling indirect measurement of concentricity without requiring direct access to deep recesses or complex optical paths.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If coordinate measuring machines are used for internal toothing measurement, then measurement accuracy is improved, but measurement time and cost increase

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidmeasurement efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The teaching gear engages automatically with the internal toothing through its gear teeth, eliminating the need for complex positioning systems. The measurement system self-adjusts as the teaching gear meshes with the internal gears, providing accurate measurement without requiring slow, methodical coordinate mapping procedures.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The spindle unit is pre-configured with the teaching gear in a ready position, and the measuring encoder is pre-calibrated. When measurement begins, the system is already prepared to capture concentricity data immediately, avoiding the time-consuming setup and calibration required by coordinate measuring machines.

Inventive Principle:
Principle #10Preliminary action

3Difficulty of detecting and measuring

If traditional measurement methods are used on components wetted with machining media, then measurement capability is limited, but component cleaning time and cost increase

Engineering Contradiction:
Improvemeasurement capabilityVSAvoidcleaning requirement
Core Design Contradiction:
Difficulty of detecting and measuringVSEase of manufacture

Solution Approach 1:

The teaching gear and spindle unit are designed as robust, simple mechanical components that can operate in contaminated environments. Rather than requiring expensive cleaning procedures to protect sensitive measurement equipment, the system uses durable mechanical parts that tolerate machining media without degradation.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Data Source

PatentEP3676562B1Device and method for measuring the true running of an internal tooth set of a component, in particular a shaft
Publication Date: 2022.03.09 THYSSENKRUPP PRESTA TECCENTER AG
  • EP3676562B1 patent drawingFigure 1~3
  • EP3676562B1 patent drawingFigure 4~5
  • EP3676562B1 patent drawingFigure 6~8

AI summary

The invention relates to a device and to a method for measuring the true running of an internal tooth set of a component, in particular a shaft, wherein the device has at least one determination settlement for determining a true running deviation, comprising a spindle unit comprising a tapping spindle having a gauge gear wheel arranged at a first end of the tapping spindle for tapping off the true running of the internal tooth set of the component, and an output spindle for transmitting the true running that is tapped off from the tapping spindle to a measuring unit, wherein the output spindle is arranged indirectly or directly on a second end of the tapping spindle, which is opposite the first end of the tapping spindle, and a spindle holder, at least for holding and positioning the tapping spindle or the output spindle, advantageously the spindle unit, an adjusting element at least for positioning at least the gauge gear wheel connected to the tapping spindle, and the measuring unit for comparing the true running tapped off with reference values.