Linear Drive Unit for Sliding Door

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Solution Overview

Problem

Existing automatic sliding door drive units face challenges in achieving minimal noise and efficient driving forces due to their large size, which is not compatible with modern architectural designs requiring slim linear drive units that are rigid and silent.

Innovation Solution

A linear drive unit with a flexible mounting of a threaded spindle driven by an electric motor through an elastic coupling, featuring a floating threaded nut and a silencer, which reduces noise and vibration by using a PVC or rubber spacer and a DC coreless electromotor with an electric choke for stable operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If toothed belts and multiple mechanical elements are used in the drive assembly, then the driving force and reliability are improved, but the noise level increases and the device size becomes larger

Engineering Contradiction:
Improvedriving forceVSAvoidnoise
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the traditional toothed belt mechanical transmission system with a direct threaded spindle mechanism. The electric motor directly drives the threaded spindle through an elastic coupling, eliminating multiple intermediate mechanical elements (toothed belts, pulleys, gears) that generate noise. This substitution maintains reliable driving force through the threaded spindle's direct mechanical advantage while significantly reducing noise from mechanical friction and tooth engagement.

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

Solution Approach 2:

The patent extracts and removes the noisy intermediate transmission elements (toothed belts, pulleys, multiple mechanical connectors) from the drive assembly. By taking out these harmful mechanical intermediaries and retaining only the essential threaded spindle mechanism, the system achieves silent operation while preserving the core function of converting rotational motion to linear motion for door activation.

Inventive Principle:
Principle #2Taking out (Extraction)

2Volume of moving object

If the drive unit size is minimized to meet modern architectural designs, then the aesthetic appearance and space efficiency are improved, but the rigidity and mounting stability become problematic

Engineering Contradiction:
Improvedrive unit sizeVSAvoidrigidity
Core Design Contradiction:
Volume of moving objectVSStability of the object's composition

Solution Approach 1:

The patent merges the motor, threaded spindle, elastic coupling, and mounting components into a single integrated linear drive unit. This consolidation achieves minimal drive unit size that meets modern architectural requirements while maintaining structural rigidity through the unified design. The oblong carrier integrates multiple functions, and the elastic coupling provides mounting stability without increasing overall size.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent employs a nested arrangement where the threaded spindle is mounted within the oblong carrier, the elastic coupling connects components within the compact structure, and the guide is integrated into the carrier body. This nesting approach allows multiple functional elements to be contained within a minimal volume while maintaining the rigidity and stability of each component through proper structural integration.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Productivity

If a rigid connection is used between the threaded spindle and motor, then the transmission efficiency is improved, but the noise and vibration increase

Engineering Contradiction:
Improvetransmission efficiencyVSAvoidvibration
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces an elastic coupling as an intermediary element between the electric motor and the threaded spindle. This elastic mediator transmits rotational motion and driving force efficiently from the motor to the spindle while absorbing vibrations and reducing noise. The elastic coupling acts as a buffer that maintains transmission efficiency without the harmful effects of rigid direct connection, allowing smooth power transfer with vibration isolation.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 provides a silent, reliable, and durable mechanism for automatic sliding doors with minimal noise and efficient operation, suitable for various door configurations, including single and double-winged doors, while ensuring low energy consumption and easy manual operation during power outages.

Implementation Method 1

a flexible mounting of a threaded spindle driven by an electric motor through an elastic coupling

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

DC coreless electromotor

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

DC coreless electromotor with an electric choke for stable operation

Methodology Applied
Scientific EffectElectrical resistance: Electrical Resistance

Implementation Method 4

a PVC or rubber spacer and a DC coreless electromotor with an electric choke for stable operation

Methodology Applied
Scientific EffectVibration damping: Damping

Data Source

PatentEP3568551B1Linear drive unit for automatic sliding door
Publication Date: 2021.10.27 DOORSON D O O
  • EP3568551B1 patent drawingFigure 1
  • EP3568551B1 patent drawingFigure 2~2a
  • EP3568551B1 patent drawingFigure 3

AI summary

The present invention belongs to the field of construction, more precisely to the field of mechanisms for movement or automatic opening and closing of sliding door. The present invention may also be classified to the field of machine assemblies in combination with electromechanic drives. The linear drive unit for automatic sliding door according to the invention comprises a guide with a spacer in an oblong holder, to which a drive motor is mounted, the drive motor through a motor console and an elastic coupling transfers rotational movement to a threaded spindle, of which a floating threaded nut translationally moves two carriages with a wing of sliding door. At the end the threaded spindle is through the elastic coupling mounted into a supporting console, wherein axes of all elements are in the same longitudinal axis.