Vehicle Drivetrain Actuator With Magnetic Gear Position Sensing

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Solution Overview

Problem

Existing actuators for vehicle transmissions, particularly bicycles, are bulky due to complex mechanisms and lack compactness and ease of angular position detection, necessitating user intervention for gear changes.

Innovation Solution

A compact actuator design incorporating a face gear mechanism with a worm gear and magnetic position detection, utilizing a face gear with a toothed wheel and a worm gear mechanism to determine the angular position of the torque output element, integrated with a magnetic target and Hall effect sensor for precise positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a complex mechanism is used between the electric motor and the actuator's output element, then the actuator can achieve gear changing function, but the actuator becomes bulky and loses compactness

Engineering Contradiction:
Improvegear changing functionVSAvoidactuator size
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The patent merges the gear wheel and torque output element into a single integrated component. The gear wheel serves dual functions: transmitting motion from the pinion and providing the torque output interface. This elimination of separate transmission elements significantly reduces the actuator's volume while maintaining gear changing capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The gear wheel is designed as a multi-functional element that simultaneously acts as a transmission gear and a torque output element. This universal design allows the actuator to achieve gear changing function without requiring additional dedicated transmission components, thereby reducing overall size.

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

2Measurement precision

If angular position detection means is integrated into the actuator, then precise position detection is achieved, but the device complexity increases

Engineering Contradiction:
Improveangular position detection precisionVSAvoidactuator structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical position detection mechanisms with a magnetic field-based detection system. A magnetic target attached to the driven shaft interacts with a magnetic sensor, enabling precise angular position detection through non-contact magnetic field sensing rather than mechanical linkages.

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

Solution Approach 2:

The magnetic target serves as an intermediary element that converts the rotational position of the driven shaft into a detectable magnetic field signal. This intermediary approach simplifies the detection system by decoupling the mechanical rotation from the sensing mechanism, requiring only a simple magnetic sensor and target assembly.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

The actuator achieves compactness and precise gear position detection, enabling automatic gear changes without user effort, enhancing vehicle operation efficiency.

Implementation Method 1

said driven shaft comprising a magnetic target facing a sensor

Methodology Applied
Scientific EffectMagnetic field detection: Magnetic Field

Implementation Method 2

integrated with a magnetic target and Hall effect sensor for precise positioning

Methodology Applied
Scientific EffectHall effect: Hall Effect

Data Source

PatentEP4381208B1Actuator for actuating at least one movable member of a vehicle drivetrain
Publication Date: 2025.11.12 VALEO ELECTRIFICATION
  • EP4381208B1 patent drawingFigure 1~2
  • EP4381208B1 patent drawingFigure 3~4
  • EP4381208B1 patent drawingFigure 5~7

AI summary

The present invention relates to an actuator (1, 1') for actuating at least one movable member of a vehicle drivetrain, the actuator (1, 1') comprising an electric motor (2) having a drive shaft (21) on which a first pinion (22, 22') is mounted, a gear (3, 3') having a toothing (31, 31') that meshes with the pinion (22, 22') and a torque output element (33) that is capable of being coupled to the drivetrain, characterised in that the gear (3, 3') further comprises a worm gear mechanism (4, 4') that meshes with a second pinion (41, 41') mounted on an output shaft (40), the output shaft (40) comprising a magnetic target (44) facing toward a sensor (50).