Overlapping Gear Arrangement for Compact Drive Rod Lining

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Solution Overview

Problem

Existing gear arrangements for window and door connecting rod fittings have limited load-carrying capacity due to the 'flying' bearing of the output-side gear element, which restricts the transmission's ability to handle large loads and requires larger gear housings, weakening the window or door sash.

Innovation Solution

The gear arrangement features a free space on the overlapping side between the covered and overlapping gear elements, allowing for a larger mutual overlap and closer placement of their axes of rotation, enabling a more compact design that accommodates long strokes without cantilever mounting, and provides bearing points on both sides for enhanced load-bearing capacity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the output-side gear element is mounted with a 'flying' bearing (single-sided bearing point), then the gear arrangement can be simpler and more compact, but the load-carrying capacity is limited

Engineering Contradiction:
Improvegear arrangement structureVSAvoidload-carrying capacity
Core Design Contradiction:
Device complexityVSStrength

Solution Approach 1:

The bearing support is segmented into two separate bearing points located on opposite sides of the gear element, rather than using a single bearing point. This allows the gear element to be supported at both ends, significantly improving load-carrying capacity while maintaining a relatively simple overall structure.

Inventive Principle:
Principle #1Segmentation

2Volume of stationary object

If the gear elements overlap more to reduce the distance between axes of rotation, then the gear housing can be smaller and more compact, but the bearing point of the covered gear element becomes constrained

Engineering Contradiction:
Improvegear housing sizeVSAvoidbearing point accessibility
Core Design Contradiction:
Volume of stationary objectVSEase of operation

Solution Approach 1:

The bearing points are positioned in the axial direction (along the axis of rotation) rather than only in the radial direction. By extending the bearing points axially beyond the overlap region, the gear elements can overlap more in the radial direction to reduce gear housing size, while the bearing points remain accessible and unconstrained in the axial dimension.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Strength

If bearing points are provided on both sides of the gear element, then the load-carrying capacity is enhanced, but the gear arrangement requires more space and becomes less compact

Engineering Contradiction:
Improveload-carrying capacityVSAvoidgear housing size
Core Design Contradiction:
StrengthVSVolume of stationary object

Solution Approach 1:

The bearing points on both sides of the gear element are merged with the gear element itself, forming an integrated structure. The bearing points are directly formed as part of the gear element body, eliminating the need for separate bearing housings or mounting structures, thereby enhancing load-carrying capacity without significantly increasing the overall gear housing volume.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2339099B1Gear assembly of a drive rod lining, drive rod lining with such a gear assembly and window, door or similar with such a drive rod lining
Publication Date: 2013.02.27 ROTO FRANK AG
  • EP2339099B1 patent drawingFigure 1
  • EP2339099B1 patent drawingFigure 2~4
  • EP2339099B1 patent drawingFigure 5

AI summary

The arrangement (1) has a gear (16) arranged at an operating device and at a drive rod. The gear has gear elements (17, 18) that are designed as tooth elements and rotatable around rotational axes (19, 20). The gear elements are displaced opposite to each other in the direction of the axes and overlap each other in a radial direction of the axes, where one of the gear elements has a bearing surface (32). A free area (33) is formed between the gear element and the bearing surface, where the other gear element is moved in the free space during rotation.