Door Drive Output Shaft Length Adaptation

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Solution Overview

Problem

Existing door drives face challenges in adapting to different mounting positions due to varying vertical distances between the door lintel and the installed door drive, requiring multiple extension element lengths or lengthy elements that need to be adjusted, which is cumbersome and inefficient.

Innovation Solution

A door drive with a length-adjustable output shaft featuring a hollow shaft and a shaft insert with clamping elements that can be displaced transversely to the axis of rotation, allowing for flexible adaptation and a play-free connection, enabling easy assembly and maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If extension elements of different lengths are kept available to adapt to different mounting positions, then the door drive can be adapted to various installation conditions, but the device complexity and inventory requirements increase

Engineering Contradiction:
Improveadaptability to different mounting positionsVSAvoidcomplexity of managing multiple extension element lengths
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The shaft insert is inserted into the hollow shaft, creating a nested structure where one component fits inside another. This allows the output shaft length to be variable while using a single hollow shaft component, eliminating the need for multiple extension elements of different lengths.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The output shaft length is made dynamically adjustable through the shaft insert that can be positioned at different locations within the hollow shaft and fixed at desired positions. This dynamic adjustability replaces the static approach of having multiple fixed-length extension elements.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If an extension element of great length is kept available and adjusted by sawing, then a single component can serve multiple lengths, but the manufacturing precision and installation time increase

Engineering Contradiction:
Improveflexibility in output shaft lengthVSAvoidprecision of length adjustment
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The output shaft is segmented into two separate components: a hollow shaft and a shaft insert. The shaft insert can be manufactured in a standard length and then positioned at different locations within the hollow shaft to achieve different effective output shaft lengths, eliminating the need for precision sawing adjustments.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The shaft insert is pre-manufactured with clamping elements and engagement elements that enable precise positioning and fixing within the hollow shaft. This preliminary preparation of the insert with built-in adjustment mechanisms eliminates the need for on-site precision cutting and adjustment.

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If the shaft insert is made freely displaceable for easy adjustment, then the assembly process is simplified, but the connection reliability and power transmission precision decrease due to play

Engineering Contradiction:
Improveease of shaft insert adjustmentVSAvoidreliability of power transmission
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The shaft insert transitions from a freely displaceable state during installation to a fixed state during operation. The clamping elements can be moved to different positions and then locked, providing both ease of adjustment and reliable fixed connection for power transmission.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Different parts of the shaft insert have different functions: the clamping elements provide adjustable positioning, while the engagement elements (such as splines or teeth) provide rigid mechanical coupling for reliable power transmission. This local differentiation of properties satisfies both adjustability and reliability requirements.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3235986B1Door drive
Publication Date: 2020.09.09 DORMAKABA DEUT GMBH
  • EP3235986B1 patent drawingFigure 1
  • EP3235986B1 patent drawingFigure 2
  • EP3235986B1 patent drawingFigure 3a

AI summary

A door drive (1) with an output shaft (2) for coupling the door drive (1) with a power transmission element (3) is described and illustrated.A door drive (1) that can be easily adapted to different mounting positions is realized according to the invention in that the output shaft (2) comprises a hollow shaft (4) and a shaft insert (5), wherein the shaft insert (5) can be inserted into the hollow shaft (4), wherein the shaft insert (5) has at least one first clamping element (5a) and at least one second clamping element (5b), wherein the clamping elements (5a, 5b) of the shaft insert (5) can be moved from a first spatial arrangement to a second spatial arrangement by relative displacement transverse to the axis of rotation of the hollow shaft (4) and/or rotation relative to each other, wherein the shaft insert (5) is movable in the hollow shaft (4) in the first spatial arrangement and the shaft insert (5) is fixed in the hollow shaft (4) by force and/or form locking in the second spatial arrangement.