Clutch Actuator Motor Safety Module for Controlled Engagement

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Solution Overview

Problem

In automated transmissions, unintended rapid clutch engagement due to motor malfunction can lead to hazardous vehicle acceleration, requiring fast driver reaction to avoid accidents, especially when the electric supply to the clutch actuator fails, and existing solutions are costly and lack controlled engagement mechanisms.

Innovation Solution

A safety device using a permanent magnet synchronous motor with a safety module and control module that short circuits the motor coils during a power failure to slow down clutch engagement, employing resistors and energy storage to manage the braking effect, allowing for controlled clutch release without additional mechanical components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the electric motor loses power supply to hold the clutch disengaged, then the clutch spring force causes rapid unintended engagement, but this creates a hazardous situation with no time for driver reaction

Engineering Contradiction:
Improveclutch control reliabilityVSAvoiddriver reaction time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary anti-action by detecting motor malfunction conditions before unintended clutch engagement occurs. The control system monitors motor current, voltage, and position to identify failure modes such as power supply loss, then activates safety functions to counteract the harmful effect by controlling the release bearing to prevent rapid clutch engagement, thereby preserving driver reaction time.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The patent implements preliminary action by continuously monitoring motor parameters (current, voltage, position) during normal operation to detect malfunction conditions before they lead to unintended engagement. The system prepares safety control functions in advance, so when a failure is detected, the control system can immediately intervene to slow down clutch engagement and provide driver reaction time.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If additional mechanical components are added to mechanically lock the motor in disengaged position, then clutch engagement can be controlled, but this increases device complexity and cost

Engineering Contradiction:
Improveclutch engagement controlVSAvoidmechanical components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces mechanical locking components with an electronic control system that monitors motor parameters and activates safety functions through electronic control of the release bearing. Instead of adding mechanical locks, the system uses electronic detection of malfunction conditions (current, voltage, position) and electronic control signals to manage clutch engagement, thereby reducing mechanical complexity while maintaining safety.

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

Solution Approach 2:

The patent enables the existing motor and control system to serve its own safety function by monitoring its own operational parameters (current, voltage, position) and detecting its own malfunction conditions. The control system uses the existing infrastructure to identify failures and activate safety functions, eliminating the need for separate mechanical safety locking components.

Inventive Principle:
Principle #25Self-service

3Productivity

If the clutch engagement time is reduced to less than 50-100 ms for fast control, then transmission response is improved, but the driver cannot react to unintended engagement

Engineering Contradiction:
Improvetransmission control speedVSAvoiddriver reaction time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent implements feedback by continuously monitoring motor parameters (current, voltage, position) during clutch operation and using this information to detect malfunction conditions. The control system receives feedback about the clutch state and motor health, then activates safety functions when abnormal conditions are detected, allowing the system to maintain fast engagement during normal operation while providing protection when failures occur.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent applies dynamics by enabling the clutch control system to adapt its behavior based on operational conditions. During normal operation, the system allows fast engagement for improved productivity. When malfunction conditions are detected through parameter monitoring, the system dynamically switches to a safety mode that controls the release bearing to slow down engagement, thereby adapting the engagement speed to the operational context.

Inventive Principle:
Principle #15Dynamics

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 slows down unwanted clutch engagement, providing the driver with sufficient time to react and maintain vehicle control during actuator failures, enhancing safety and reducing costs by eliminating the need for extra mechanical components.

Implementation Method 1

A permanent magnet synchronous motor (PMSM) is provided to drive a clutch actuator in an automatic driveline. The PMSM has a rotor with permanent magnets and a stator with at least three coils as phases.

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

A safety device according to the invention is provided to control the motor and comprises a safety module and a safety control module. The safety module includes switches for each of the coils of the motor, respectively... the coils are shorted and the release of the clutch spring is slower than in a normal power-off situation.

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 3

The springs are disposed within a pressure plate assembly which is bolted to the flywheel. A mechanical linkage that controls the pressure plate spring mechanism is usually actuated with an electronically controlled actuator.

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3531551B1Device and method to reduce clutch engagement speed
Publication Date: 2023.05.24 KNORR BREMSE SYSTEME FUER NUTZFAHIZEUGE GMBH
  • EP3531551B1 patent drawingFigure 1
  • EP3531551B1 patent drawingFigure 2

AI summary

A safety device comprising a safety module (3) and a safety control module (4) and a method to reduce a speed of an unwanted clutch engagement when a malfunction of a motor (2) for a clutch control actuator occurs (the power supply for the motor is interrupted), so that a driver can have more time to react in such situation.