Electromechanical Actuator Coupling for Compact Misalignment Compensation

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Solution Overview

Problem

Existing electromechanical actuators for blackout devices have a large footprint and torque transmission devices that do not allow for dimension reduction while maintaining minimum torque transmission, leading to misalignments and inefficiencies.

Innovation Solution

A torque transmission device with inclined arms and beams, allowing for elastic deformation to compensate for axial, radial, and angular misalignments between the electric motor rotor and the reducer input shaft, reducing friction and noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a one-piece torque transmission device is used, then structural simplicity is improved, but the footprint (length and outside diameter) increases

Engineering Contradiction:
Improvestructural simplicityVSAvoidfootprint
Core Design Contradiction:
Device complexityVSArea of stationary object

Solution Approach 1:

The torque transmission device is segmented into multiple independent components: a first component with first arms, a second component with second arms, and a third component with a third arm. These segmented components can be arranged in a compact configuration, reducing the overall footprint while maintaining the structural simplicity benefit through their integrated cooperative function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a two-dimensional planar arrangement (perpendicular arms in a single plane) to a three-dimensional spatial configuration where arms are distributed across multiple planes and orientations. The third arm extends in a direction different from the first two arms, utilizing the third dimension to reduce footprint while maintaining torque transmission effectiveness.

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

2Ease of manufacture

If arms are positioned perpendicularly to beams, then manufacturing simplicity is improved, but torque transmission efficiency deteriorates due to misalignments

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidtorque transmission efficiency
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent modifies the geometric parameters of the torque transmission device by inclining the arms at specific angles (between 15° and 75° relative to the plane containing the beams) rather than positioning them perpendicularly. This parameter change optimizes torque transmission efficiency by reducing misalignments between the motor shaft and reducer input shaft, while the inclined configuration remains manufacturable using standard machining processes.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces dynamic adaptability through the inclined arm configuration, which allows the torque transmission device to accommodate misalignments and variations in operation. The inclined geometry provides a degree of flexibility in handling angular and radial deviations, improving reliability without sacrificing manufacturing simplicity.

Inventive Principle:
Principle #15Dynamics

3Area of stationary object

If the footprint is reduced, then installation space is improved, but torque transmission capability deteriorates

Engineering Contradiction:
Improveinstallation spaceVSAvoidtorque transmission capability
Core Design Contradiction:
Area of stationary objectVSPower

Solution Approach 1:

The patent applies local quality optimization by concentrating the torque transmission function in the inclined arms while using the beams primarily for structural support and positioning. This localized functional assignment allows the device to achieve high torque transmission capability in a compact footprint, as each component is optimized for its specific function rather than all components being oversized for maximum torque.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent employs a composite structure combining beams and inclined arms made from materials optimized for their specific roles. The beams provide rigid structural support, while the inclined arms are designed for optimal torque transmission. This composite approach enables compact dimensions while maintaining sufficient torque transmission capability for blackout device applications.

Inventive Principle:
Principle #40Composite materials

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 solution effectively transmits torque while minimizing misalignments and friction, enhancing efficiency and reducing noise generation.

Implementation Method 1

allowing for elastic deformation to compensate for axial, radial, and angular misalignments between the electric motor rotor and the reducer input shaft

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP4417829B1Electromechanical actuator and concealment device comprising such an electromechanical actuator
Publication Date: 2025.11.26 SOMFY ACTIVITES SA
  • EP4417829B1 patent drawingFigure 1
  • EP4417829B1 patent drawingFigure 2
  • EP4417829B1 patent drawingFigure 3

AI summary

An electromechanical actuator comprises an electric motor, a gearbox, and a torque transmission device (31) including a single-piece component (32). An input shaft of the gearbox is coupled to the rotor of the electric motor via the component (31). The component (32) comprises a first part (48), a second part (49), a plurality of first beams (50) extending from the first part (48), a plurality of second beams (51) extending from the second part (49), and a plurality of arms (52) extending from one of the first beams (50) and from one of the second beams (51). Each arm (52) is inclined relative to one of the first beams (50) by a first value of inclination (a1) between 25° and 65° and relative to one of the second beams (51) by a second value of inclination (a2) between 25° and 65°.