Roll Stabiliser Actuator with Integrated Vernier Motor Transmission

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Solution Overview

Problem

Existing active roll stabilizers face challenges in optimizing installation space and drive efficiency, particularly due to the axial arrangement of electric motors and transmissions, which limits their compactness and increases weight and energy consumption.

Innovation Solution

The integration of a Vernier motor with the transmission within the electric motor housing allows for a compact design, reducing the axial extent of the actuator and enabling a more efficient and lightweight roll stabilizer, where the transmission is arranged within the rotor and stator, and a planetary gear is used to achieve high torque and quiet operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If the electric motor and transmission are arranged axially next to each other in the actuator housing, then the drive can achieve high torque through gear translation, but the axial extent of the actuator increases significantly

Engineering Contradiction:
Improveactuating forceVSAvoidaxial extent of actuator
Core Design Contradiction:
ForceVSLength of moving object

Solution Approach 1:

The transmission is arranged essentially within the electric motor, with the planetary gear set nested inside the motor housing. The sun gear is concentric with the motor shaft, planet gears are arranged radially around the sun gear, and the ring gear forms the outer boundary. This nested configuration allows the transmission to be contained within the motor's radial dimensions rather than extending axially, significantly reducing the overall axial extent of the actuator while maintaining the high torque capability through gear multiplication.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Length of moving object

If the transmission is arranged within the electric motor, then the axial extent is reduced, but the installation space and drive efficiency need optimization

Engineering Contradiction:
Improveaxial extent of actuatorVSAvoiddrive efficiency
Core Design Contradiction:
Length of moving objectVSProductivity

Solution Approach 1:

The electric motor and transmission are merged into a single integrated actuator unit. The motor housing serves as the transmission housing, the motor shaft is directly connected to the sun gear, and the ring gear is mounted on the housing. This merging eliminates the need for separate motor and transmission housings, reduces the number of coupling interfaces, and allows the transmission to be positioned optimally within the motor's radial space, thereby maintaining high drive efficiency while achieving compact axial dimensions.

Inventive Principle:
Principle #5Merging (Combining)

3Volume of moving object

If a planetary gear is used inside the electric motor, then high torque is achieved with compact dimensions, but the manufacturing complexity increases

Engineering Contradiction:
Improveactuator volumeVSAvoidmanufacturing complexity
Core Design Contradiction:
Volume of moving objectVSEase of manufacture

Solution Approach 1:

The actuator housing serves multiple functions: it houses the electric motor, contains the planetary gear transmission, provides mounting surfaces for the stabilizer elements, and acts as the structural connection to the vehicle chassis. The motor shaft serves both as the rotor shaft and as the sun gear. The ring gear is mounted directly on the housing, eliminating the need for a separate transmission case. This multi-functionality reduces the number of separate components and assembly steps, thereby reducing manufacturing complexity despite the sophisticated planetary gear design.

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

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

This configuration results in a significantly reduced installation space requirement, improved energy efficiency, lower noise, and reduced weight, enhancing the comfort and stability of vehicle handling by minimizing rolling movements without the need for additional space, and is applicable to various actuator systems.

Implementation Method 1

an electric motor used for driving has an output shaft which is offset from the axis of rotation of the stabilizer elements

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

A passive roll stabilizer is separated and an actuator consisting of engine and transmission is connected between the stabilizer elements. This actuator can twist the two stabilizer elements against each other

Methodology Applied
Scientific EffectMechanical advantage: Mechanical Advantage

Data Source

PatentEP3615359B1Roll stabiliser and use of a roll stabiliser in a motor vehicle
Publication Date: 2021.01.20 ZF FRIEDRICHSHAFEN AG
  • EP3615359B1 patent drawingFigure 1
  • EP3615359B1 patent drawingFigure 2
  • EP3615359B1 patent drawingFigure 3

AI summary

The invention relates to a roll stabiliser for a motor vehicle, comprising an actuator (135, 235) having a housing (137, 237) with a first stabiliser element (110, 210) coupled thereto and an electric motor (150, 250) disposed in the housing (137, 237), wherein the transmission (160, 260) is coupled on the drive side to the electric motor (150, 250) and the transmission (160, 260) is coupled on the output side to a second stabiliser element (115, 215). The invention is characterised by a transmission (260) which is arranged substantially within the electric motor. The invention also relates to the use of a roll stabiliser in a chassis on at least one axle of a motor vehicle.