Motor Vehicle Door Drive Play Compensation Mechanism

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Solution Overview

Problem

Existing door drives for motor vehicle doors or flaps face challenges in providing seamless game compensation, leading to uncomfortable operation and increased wear due to component tolerances and wear over time, which existing solutions like damping devices and preload members fail to adequately address.

Innovation Solution

The door drive incorporates a power transmission element and a compensation element, both formed as circular segments with intervention openings, where the output element interacts with both, creating a relative angle through differing angular speeds, resulting in effective game compensation that can vary with elastic coupling, ensuring robust and durable operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a damping device is used to compensate for angular play in the load torque lock, then the angular play at the load torque lock is reduced, but the play in other parts of the drive train (rack and pinion) remains unaddressed

Engineering Contradiction:
Improveangular play compensationVSAvoidcoverage of play compensation
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The drive train is segmented into multiple independent play compensation mechanisms: a damping device for the load torque lock and a prestressing element for the rack and pinion. Each mechanism addresses the play specific to its component, ensuring comprehensive coverage throughout the entire drive train.

Inventive Principle:
Principle #1Segmentation

2Reliability

If a prestressing element is used to ensure toothed engagement between the rack element and output gear, then play is compensated, but the prestressing element undergoes fatigue and wear over time

Engineering Contradiction:
Improvetoothed engagementVSAvoidservice life
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The prestressing element is designed to automatically adjust and maintain optimal preload forces throughout the service life of the door drive. The system self-regulates to compensate for wear and fatigue, ensuring consistent toothed engagement without manual intervention or additional maintenance.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If control technology is improved to address play compensation, then adjustment accuracy is enhanced, but the control system robustness is compromised due to play and wear over service life

Engineering Contradiction:
Improveadjustment accuracyVSAvoidcontrol system robustness
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

Play compensation is achieved through mechanical preloading and damping mechanisms that are built into the drive train structure. This preliminary mechanical action eliminates the need for complex control algorithms to compensate for play, thereby maintaining control system robustness while achieving high adjustment accuracy.

Inventive Principle:
Principle #10Preliminary action

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 solution provides automatic and variable game compensation, enhancing the feel and lifespan of the door drive by allowing the relative angle between elements to adjust, thus mitigating wear and maintaining performance over time.

Implementation Method 1

both the force transmission element and the compensating element are connected to one another in an elastic and rotatable manner

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4146896B1Door drive for a motor vehicle door or motor vehicle flap
Publication Date: 2025.01.29 KIEKERT AG
  • EP4146896B1 patent drawingFigure 1
  • EP4146896B1 patent drawingFigure 2
  • EP4146896B1 patent drawingFigure 3

AI summary

The invention relates to a door drive for a motor vehicle door or motor vehicle flap. This is generally provided with an electromotive drive (2) and a transmission (3, 4) connected downstream of the drive (2). In addition, a force transmission element (5) is provided, which is operatively connected to a leaf (1) of the motor vehicle door or motor vehicle flap. An output element (4a) of the transmission (3, 4) and the force-transmission element (5) are coupled by a toothing (6, 7, 8) with compensation for play. According to the invention, the toothing (6, 7, 8) is formed in two parts for engaging both into the force transmission element (5) and into a compensation element (9) that is rotatably, elastically coupled to the force transmission element (5). For play-free positioning, the compensation element (9) has a differing angular velocity from the force transmission element (5) in order to create a relative angle (α1 - α2) between the two elements (5, 9).