Shedding Motor Rotor Layout for High Torque Without Reducers

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Solution Overview

Problem

Existing shedding machines for looms face challenges with high rotational inertia, excessive energy consumption, and low efficiency due to the use of electric actuators with low torque, which are constrained by space and inertia requirements, and the addition of reducers leads to inefficiencies and increased cost.

Innovation Solution

A shedding machine design featuring a rotary electric motor with a rotor shaft and cylindrical part that minimizes inertia, utilizing a stator with laminations and permanent magnets to achieve high torque without mechanical reducers, allowing efficient operation at nominal speed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a reducer is added at the output of the motor rotor, then higher torque is obtained at the output, but the efficiency decreases due to reducer losses and the moment of inertia increases significantly

Engineering Contradiction:
ImprovetorqueVSAvoidefficiency
Core Design Contradiction:
ForceVSLoss of energy

Solution Approach 1:

The patent replaces the mechanical reducer system with an electromagnetic torque amplification system. The inner rotor generates a magnetic field that interacts with the outer rotor to produce amplified torque directly at the motor output, eliminating the need for mechanical gears and reducing energy losses while maintaining high torque output.

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

2Use of energy by moving object

If the rotational inertia of the motor rotor is minimized, then vibrations and energy consumption are reduced, but the torque capability decreases

Engineering Contradiction:
Improveenergy consumptionVSAvoidtorque
Core Design Contradiction:
Use of energy by moving objectVSForce

Solution Approach 1:

The patent applies local quality by creating a concentrated magnetic field interaction zone between the inner and outer rotors. The magnetic field is localized in the air gap between the rotors, allowing torque amplification to occur in a specific region without requiring the entire rotor assembly to have high inertia.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The motor employs a composite structure with two separate rotors (inner and outer) that work together magnetically. This composite design allows the system to achieve high torque through magnetic interaction while keeping individual rotor inertias low, as neither rotor needs to independently generate the full torque.

Inventive Principle:
Principle #40Composite materials

3Volume of moving object

If the space available for arranging motors is constrained, then the motor size is reduced, but the torque capability is limited

Engineering Contradiction:
Improvemotor sizeVSAvoidtorque
Core Design Contradiction:
Volume of moving objectVSForce

Solution Approach 1:

The patent implements a nested configuration where the inner rotor is positioned inside the outer rotor, creating a compact concentric structure. This nesting allows the motor to generate high torque through the magnetic interaction between the two rotors while occupying minimal radial space, effectively doubling the magnetic interaction surface area within a compact footprint.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 design reduces moment of inertia, maintains high torque, and enhances efficiency by operating closer to nominal speed, minimizing size and cost increases while optimizing energy use.

Implementation Method 1

a stator, secured to the frame, a rotor, arranged in the stator and comprising a cylindrical part... permanent magnets, arranged on the outer peripheral wall of the cylindrical part... each permanent magnet comprising a respective outer surface, the outer surfaces facing the winding teeth

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4624646A1Shedding machine and shedding assembly comprising a group of such machines
Publication Date: 2025.10.01 STAUBLI FAVERGES SA
  • EP4624646A1 patent drawingFigure 1
  • EP4624646A1 patent drawingFigure 2
  • EP4624646A1 patent drawingFigure 3

AI summary

The machine (9) comprises a rotary electric motor, a crank, a driving lever and a driving rod. The stator (23) of the motor comprises winding laminations (33), extending radially between a stator outer diameter (D23e) and a stator inner diameter (D23i), and electrical windings (39). The rotor (29) of the motor comprises a rotor shaft (51), centered on a main axis (A1), surrounded by a cylindrical portion (53) of the rotor and secured to the cylindrical portion and the crank, and permanent magnets (57). A ratio of the external stator diameter (D23e) to a length (L53) of the cylindrical part (53), measured parallel to the main axis without exceeding the permanent magnets, is between 2.0 and 4.0, preferably between 2.5 and 3.5, more preferably between 2.8 and 3.2.