Park Lock Mechanism With Lateral Compliance for Torque Shock Relief

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Solution Overview

Problem

Existing locking mechanisms in vehicles face challenges with positioning inaccuracies and dynamic torque loads during the locking process, leading to shock loads and increased wear on the locking actuator and drive train components.

Innovation Solution

A locking mechanism with a form-locking element that allows a degree of freedom of movement outside the form-locking area, compensating for positioning inaccuracies and absorbing torque loads by transferring them to a peripheral stop, reducing dynamic torque peaks and shock loads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the form-locking element is rigidly fixed to the locking actuator, then the locking mechanism is simple and cost-effective, but positioning inaccuracies cause shock loads and torque peaks during locking

Engineering Contradiction:
Improvelocking reliabilityVSAvoidshock loads and torque peaks
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The form-locking element is designed with a degree of freedom of movement relative to the locking actuator, allowing it to dynamically adjust its position during the locking process. This movement absorbs positioning inaccuracies and prevents rigid transmission of shock loads to the actuator, resolving the contradiction between simple rigid fixation and protection against harmful dynamic loads.

Inventive Principle:
Principle #15Dynamics

2Object-affected harmful factors

If the form-locking element allows movement to compensate positioning inaccuracies, then shock loads are reduced, but the device complexity increases

Engineering Contradiction:
Improvedynamic torque loadsVSAvoidlocking mechanism complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The form-locking element is segmented into a locking portion that engages with the recess and a movement portion that provides the degree of freedom. This segmentation allows the element to independently perform locking function and position adjustment, compensating for inaccuracies without requiring complex additional mechanisms, thus reducing device complexity while maintaining shock load protection.

Inventive Principle:
Principle #1Segmentation

3Ease of manufacture

If greater positioning tolerance is allowed, then manufacturing costs are reduced, but locking precision and reliability deteriorate

Engineering Contradiction:
Improvemanufacturing costVSAvoidlocking alignment precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The form-locking element acts as an intermediary between the locking actuator and the lockable element. Its ability to move provides a buffer that accommodates manufacturing tolerances in both the actuator and the lockable element, allowing greater positioning tolerance without compromising locking precision or reliability, thus reducing manufacturing costs.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4441400B1Locking mechanism, park lock and vehicle
Publication Date: 2025.10.01 SCHAEFFLER TECHNOLOGIES AG & CO KG
  • EP4441400B1 patent drawingFigure 1a~1c
  • EP4441400B1 patent drawingFigure 2
  • EP4441400B1 patent drawingFigure 3a~3b

AI summary

The invention relates to a locking mechanism (2), more particularly for a vehicle, between a locking actuator and a rotatable, lockable element (4) having a cutout (6), into which an actuatable form-locking element FE of the locking actuator can be partly interlockingly moved in an axial stroke movement in order to lock the element (4). The locking actuator has, outside of a region of form-locking connection between the form-locking element FE and the lockable element (4), a degree of freedom of motion for the form-locking element perpendicular to the axial stroke movement of the form-locking element FE and up to an associated stop (14), up to which the form-locking element FE can be deflected during a locking process and after the end of the locking process. By means of this degree of freedom of motion, positioning inaccuracies between the form-locking element FE and the cutout (6) can be compensated for during the locking process. Furthermore, by means of this degree of freedom of motion, dynamic torque loads of a drive train can be reduced during the locking process and in particular after the end of the locking process. The invention also relates to a park lock and a vehicle having a locking mechanism of this type.