Encoder Wheel Axial Tooth Segmentation for Radial Space Reduction

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Solution Overview

Problem

Existing sensor wheels for internal combustion engines are bulky and heavy due to their radial extent, which limits space-saving potential and increases weight, while also requiring unnecessary material for signal generation.

Innovation Solution

The sensor wheel design features axially shortened tooth parts with upper tooth parts protruding beyond lower tooth parts, allowing for reduced radial installation space and weight, with adjustable rigidity through varying height-to-depth ratios, and optional recesses for precise positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the tooth structure has upper and lower tooth sections extending over the entire axial length, then the encoder wheel achieves sufficient signal quality and robustness, but it occupies a relatively large installation space in the radial direction and has increased weight

Engineering Contradiction:
Improvesignal quality and robustnessVSAvoidradial installation space
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The tooth structure is segmented into upper tooth sections and lower tooth sections with different axial lengths. The lower tooth sections are axially shortened compared to the upper tooth sections, creating a stepped configuration that reduces radial installation space while maintaining signal generation capability through the upper sections.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from a uniform axial length in all tooth sections to a differentiated axial length configuration. By varying the axial dimension of different tooth sections, the design achieves space reduction in the radial direction while preserving the necessary signal quality through the extended upper tooth sections.

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

2Strength

If the tooth structure has upper and lower tooth sections extending over the entire axial length, then the encoder wheel achieves sufficient structural stiffness, but it has increased weight

Engineering Contradiction:
Improvestructural stiffnessVSAvoidencoder wheel weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

Material is extracted from the lower tooth sections by axially shortening them compared to the upper tooth sections. This removal of unnecessary material reduces the overall weight of the encoder wheel while the upper tooth sections maintain the structural stiffness required for robust operation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Different axial lengths are assigned to different tooth sections based on their functional requirements. The upper tooth sections maintain full axial length for signal generation and structural integrity, while the lower tooth sections are shortened where full length is not necessary, optimizing the weight-strength ratio.

Inventive Principle:
Principle #3Local quality

3Volume of moving object

If the lower tooth sections are axially shortened, then radial installation space is reduced, but the robustness during manufacturing may be compromised

Engineering Contradiction:
Improveradial installation spaceVSAvoidmanufacturing robustness
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The design creates a dynamic balance between axial length and structural robustness. The lower tooth sections are shortened to reduce radial space, while the upper tooth sections maintain sufficient axial length to ensure manufacturing robustness and operational reliability, creating an optimized compromise configuration.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3012636B1Encoder wheel
Publication Date: 2019.08.14 CARL FREUDENBERG KG
  • EP3012636B1 patent drawingFigure 1
  • EP3012636B1 patent drawingFigure 2
  • EP3012636B1 patent drawingFigure 3

AI summary

A encoder wheel (1) comprising an annular base body (2) that can be mounted on a shaft, wherein a tooth structure (4) projects axially from the base body (2), the tooth structure (4) having a wave-like structure with upper tooth parts (5) and lower tooth parts (6), the upper tooth parts (5) being designed as wave crests and the lower tooth parts (6) as wave troughs. With regard to the objective of designing and further developing an encoder wheel of the aforementioned type in such a way that it can be used in a space-saving manner with the lowest possible weight in the radial direction, the lower tooth parts (6), namely the wave troughs, and the upper tooth parts (5), i.e., the wave crests, extend to different distances in the axial direction. This creates individual teeth in an axial end region, which are separated by gaps, followed by an axial wave-shaped region that ensures increased stiffness of the encoder wheel.