Shift Collar Sensing in Axle Assemblies for Precise Position Detection

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Solution Overview

Problem

Current axle assemblies lack effective methods to accurately detect the rotational position and speed of the shift collar, which is crucial for efficient torque transmission and gear shifting, leading to potential inefficiencies and reliability issues.

Innovation Solution

Incorporating detection features on the shift collar that generate distinct signals based on their axial position, allowing a sensor to provide a duty cycle indicative of the shift collar's position and rotational speed, thereby enabling precise control and redundancy in shift mechanism operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If no sensor is used to detect shift collar position, then the axle assembly design is simpler, but the detection precision of shift collar position and speed is insufficient

Engineering Contradiction:
Improvedetection precision of shift collar position and speedVSAvoidaxle assembly design complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines the shift collar structure with detection features integrated into it, merging the shifting function and detection function into a single component. This eliminates the need for separate sensors while providing accurate position and speed detection through the interaction of detection features with sensor elements in the stator assembly.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The shift collar is designed with multi-functionality, serving both as the shifting mechanism and as the carrier of detection features. The detection features on the shift collar work with the stator sensor elements to provide position and speed information, making the shift collar a universal component that performs multiple functions.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If separate sensors are used to detect shift collar position, then the detection reliability is improved, but the device complexity increases

Engineering Contradiction:
Improveshift mechanism operation reliabilityVSAvoidnumber of sensors and components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the detection functionality into the existing stator assembly of the electric motor module. The stator elements serve dual purposes: generating motor torque and detecting shift collar position and speed, thereby improving reliability without adding separate sensor systems.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The stator assembly serves itself by performing both motor function and detection function. The same stator elements that generate electromagnetic forces also detect the position and speed of the shift collar through magnetic interactions with the detection features, eliminating the need for external sensors.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3981627B1Axle assembly having a sensor for detecting a shift collar
Publication Date: 2024.12.04 ARVINMERITOR TECHNOLOGY LLC
  • EP3981627B1 patent drawingFigure 1
  • EP3981627B1 patent drawingFigure 2
  • EP3981627B1 patent drawingFigure 3

AI summary

An axle assembly having a shift collar (504) and a sensor (580). The shift collar may be rotatable about a first axis (70) and moveable along the first axis. The sensor may detect detection features (542) associated with the shift collar and provide a signal that may be indicative of rotation of the shift collar about the first axis and positioning of the shift collar along the first axis.