Rotary Encoder Radial Alignment via Integrated D-Shaped Features

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Solution Overview

Problem

Existing rotary encoder devices require separate alignment components for proper radial alignment during installation, which complicates the manufacturing and installation processes, increases costs, and necessitates the storage and retrieval of additional components for reinstallation.

Innovation Solution

The rotary encoder device incorporates cooperating radial-alignment features on the stator and rotor that engage at a specific axial position to constrain the relative radial position, allowing for precise radial alignment without the need for separate alignment components. These features can be manually engaged and disengaged, providing a simple and cost-effective solution for installation and reinstallation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If separate alignment components are used for radial alignment during installation, then radial alignment precision is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improveradial alignment precisionVSAvoiddevice complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent merges the alignment function into the encoder housing itself by incorporating a D-shaped recess and corresponding D-shaped protrusion features directly into the stator and rotor assemblies. This eliminates the need for separate alignment components while maintaining precise radial alignment during installation and reinstallation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The encoder device performs its own alignment function through self-contained alignment features (D-shaped recess and protrusion) that are integral to the housing structure. The features automatically guide and constrain the relative radial positioning of the stator and rotor assemblies during assembly, making the system self-aligning without external alignment tools or components.

Inventive Principle:
Principle #25Self-service

2Manufacturing precision

If separate alignment components are used for radial alignment, then radial alignment precision is improved, but manufacturing cost and installation time increase

Engineering Contradiction:
Improveradial alignment precisionVSAvoidinstallation efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The alignment function is combined with the encoder housing structure through integrated D-shaped recess and protrusion features. This reduces the number of separate components that need to be manufactured, stored, and assembled, thereby reducing manufacturing costs and installation time while maintaining precise radial alignment.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The self-aligning features enable installers to quickly and accurately position the stator and rotor assemblies without requiring separate alignment tools or components. The D-shaped features automatically guide the assemblies into the correct radial relationship, reducing installation time and eliminating the need for specialized alignment procedures.

Inventive Principle:
Principle #25Self-service

3Manufacturing precision

If separate alignment components are used, then radial alignment is improved, but ease of reinstallation deteriorates due to component storage and retrieval requirements

Engineering Contradiction:
Improveradial alignmentVSAvoidease of reinstallation
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The alignment features are merged into the permanent housing structure of the encoder device. During reinstallation, the D-shaped recess and protrusion features are already present and require no additional components, tools, or storage logistics. The features are always available to guide and constrain the assemblies into proper alignment.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The encoder device maintains its own alignment capabilities permanently through the integrated D-shaped features. During reinstallation, the system is self-aligning without requiring external alignment components to be retrieved from storage or brought to the installation site. The features are inherently part of the device and require no additional preparation or component management.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4549882A1Rotary encoder device and method of mounting a rotary encoder device on a machine
Publication Date: 2025.05.07 RENISHAW PLC
  • EP4549882A1 patent drawingFigure 1
  • EP4549882A1 patent drawingFigure 2
  • EP4549882A1 patent drawingFigure 3

AI summary

A rotary encoder device comprising a stator and a rotor which are rotatable relative to each other about an axis of rotation, one of which comprises a scale and the other of which comprises a readhead for reading the scale via which the relative rotational position of the stator and rotor about said axis can be determined, wherein the stator and rotor are configured with cooperating radial-alignment features that are configured such that: at a first relative axial position of the stator and rotor the cooperating radial-alignment features are engageable so as thereby to constrain the stator and rotor at a predetermined relative radial position, and at a second relative axial position of the stator and rotor the cooperating radial-alignment features are not engageable, wherein the readhead can read the scale at said second relative axial position.