Electromechanical Actuator Torque Compensation for Progressive Force

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing electromechanical actuators for automatic gearboxes face challenges in providing a progressive increase in force for self-assisted conical couplers and input clutches, particularly during synchronization and torque transmission, where a temporary assistance from the electric actuating motor is necessary to manage the progressive force requirements.

Innovation Solution

Incorporating a torque compensation device with a piston that transmits the thrust of a spring to a flange on the input shaft, allowing the actuating motor to release energy when deviating from a central reference position and store energy when returning, thereby supporting the motor's operation and ensuring progressive force application.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If an electric motor is used to actuate self-assisted conical couplers, then the coupler can be controlled during synchronization and torque transmission, but the motor lacks sufficient torque to provide the necessary progressive force increase

Engineering Contradiction:
Improveprogressive forceVSAvoidmotor torque
Core Design Contradiction:
ForceVSPower

Solution Approach 1:

The patent employs a spring-loaded cam mechanism that acts as a counterweight system. The spring stores potential energy and the cam converts this energy into a progressive force profile, compensating for the motor's insufficient torque capacity during the coupling engagement process.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The spring is pre-compressed to store energy before the coupling operation begins. This preliminary energy storage allows the system to deliver the required progressive force without requiring the motor to generate high peak torque, effectively preparing the force assistance in advance.

Inventive Principle:
Principle #10Preliminary action

2Force

If a spring is inserted in the kinematic control chain to obtain progressiveness of force, then progressive force control is achieved for couplers, but the complexity of the control system increases

Engineering Contradiction:
Improveprogressive force controlVSAvoidcontrol system complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The cam mechanism serves as an intermediary element between the motor and the coupler. It translates the motor's rotational motion into a progressive linear force profile, mediating the interaction and providing the desired force characteristics without requiring complex electronic control algorithms.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces complex electronic force control systems with a mechanical cam-based progressive force generation system. This mechanical substitution simplifies the overall control architecture by using passive mechanical elements to achieve the progressive force profile.

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

3Reliability

If the actuating motor operates continuously to maintain coupler engagement, then the coupler remains securely engaged, but energy consumption increases

Engineering Contradiction:
Improvecoupler engagement stabilityVSAvoidmotor energy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The cam mechanism converts continuous motor rotation into periodic force application that matches the engagement requirements. The spring-loaded cam delivers force during the critical engagement phase and allows passive maintenance of position, creating a periodic action pattern that reduces continuous motor operation.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The spring-cam system provides self-service by maintaining coupler engagement passively after initial actuation. Once the cam positions the coupler, the spring tension and cam geometry automatically maintain the engagement without requiring continuous motor power, allowing the motor to enter low-power states.

Inventive Principle:
Principle #25Self-service

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 torque compensation device enhances the actuator's ability to provide progressive force control for gear couplers and input clutches, ensuring stable and efficient operation by supporting the actuating motor during deviations from the central position and storing energy for efficient return, thus addressing the need for progressive force management.

Implementation Method 1

a piston (27) which transmits the thrust of a spring (28) to a flange (8) fixed on the input shaft (7)

Methodology Applied
Scientific EffectSpring thrust: Spring

Implementation Method 2

The piston (27) transmits the thrust of the spring (28) to the input shaft (7), so as to support the actuating motor (3)

Methodology Applied
Scientific EffectMechanical advantage: Mechanical Advantage

Data Source

PatentEP2098762B1Electromechanical actuator for automatic gearbox comprising an effort controller
Publication Date: 2011.04.13 RENAULT SA
  • EP2098762B1 patent drawingFigure 1
  • EP2098762B1 patent drawingFigure 2
  • EP2098762B1 patent drawingFigure 3

AI summary

The actuator has an anti-torque device constituted by a compensator (22), a guide and a knuckle. The device releases an energy to maintain an electrical actuating motor (3) when the motor is moved away from a central reference position and stores the energy provided by the motor when the motor comes close to the position. The motor controls movement of a driving pin (16) e.g. input monodisk dry clutch, and an electrical selection motor (17) and a selection plug (18) position the pin in operating positions. A kinematic chain includes a progressive curve spring (9) in one of the positions.