Double Shaft Coupling Structure for Compact Offset Compensation

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Solution Overview

Problem

Existing compensating couplings for connecting shafts in rail vehicle drive trains face challenges in compensating for offsets with complex structures, difficult assembly, and limited space constraints.

Innovation Solution

A compensating coupling with elastic elements and a center piece connected by screw connections, featuring form-locking elements and flexible discs, allows for easy assembly and disassembly, and compensates for axial, radial, and angular misalignments while maintaining a compact design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a compensating coupling is designed to compensate for offsets between shafts, then the reliability of power transmission is improved, but the device complexity increases due to multiple components (flanges, elastic elements, center piece, screw connections)

Engineering Contradiction:
Improvepower transmission reliabilityVSAvoidcoupling structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The compensating coupling is divided into distinct functional segments: connecting flanges for shaft attachment, elastic compensating elements for offset absorption, and a center piece for structural support. This segmentation allows each component to perform its specific function efficiently while maintaining overall system reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The elastic compensating elements act as intermediary components between the rigid connecting flanges and center piece. These elastic elements mediate the transmission of torque while compensating for misalignments, thereby improving power transmission reliability without requiring direct rigid connection between all components.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If the compensating coupling uses multiple screw connections for assembling components, then the manufacturing precision and assembly reliability are improved, but the ease of assembly and disassembly deteriorates

Engineering Contradiction:
Improveassembly precisionVSAvoidassembly ease
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The coupling is segmented into modular components (flanges, elastic elements, center piece) that can be assembled independently. The screw connections are distributed across different component interfaces, allowing for systematic assembly and disassembly while maintaining precise alignment through the elastic compensating elements.

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If the compensating coupling is designed with elastic compensating elements, then the adaptability to offset variations is improved, but the weight of the coupling increases

Engineering Contradiction:
Improveoffset compensation capabilityVSAvoidcoupling weight
Core Design Contradiction:
Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The elastic compensating elements utilize material elasticity parameters to achieve offset compensation. By selecting appropriate elastic materials and geometries, the coupling can adapt to various offset conditions while minimizing weight increase compared to rigid alternative designs.

Inventive Principle:
Principle #35Parameter changes

4Duration of action of stationary object

If the compensating coupling transmits torque through elastic elements, then the durability under varying load conditions is improved, but the loss of energy through elastic deformation increases

Engineering Contradiction:
Improveservice lifeVSAvoidenergy loss through deformation
Core Design Contradiction:
Duration of action of stationary objectVSLoss of energy

Solution Approach 1:

The elastic compensating elements are pre-designed to accommodate expected load variations and misalignments. This beforehand cushioning through elastic deformation protects the rigid components from shock loads and extends service life, while the energy loss is minimized through optimized elastic element geometry and material selection.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 coupling effectively transmits torque while compensating for misalignments, offering simple assembly, reduced vibration, and a lightweight, compact design suitable for confined spaces.

Implementation Method 1

a first elastic compensating element connected to the first connecting flange... a second elastic compensating element connected to the second connecting flange... The center piece thus connects the two elastic compensation elements to each other

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP4143453B1Yielding double coupling for connecting two shafts with offset compensation
Publication Date: 2025.10.01 ZF FRIEDRICHSHAFEN AG
  • EP4143453B1 patent drawingFigure 1
  • EP4143453B1 patent drawingFigure 2a~2b
  • EP4143453B1 patent drawingFigure 3

AI summary

The invention relates to a compensating coupling (1) for offset-compensating coupling of two shafts. The compensating coupling (1) comprises a first connecting flange (2) for connection to an input shaft, a first flexible compensating element (3), which is connected to the first connecting flange (2), and a second connecting flange (4) for connection to a driven shaft and a second flexible compensating element (5), which is connected to the second connecting flange (4). The compensating coupling (1) further comprises a centre piece (6), which is arranged between the first and the second flexible compensating elements (3, 5). The first flexible compensating element (3) is connected by means of first bolted flange connections (10) to the first connecting flange (2) and by means of first centre piece bolted connections (11) to the centre piece (6). The second flexible compensating element (5) is connected by means of second bolted flange connections (12) to the second connecting flange (4) and by means of second centre piece bolted connections (13) to the centre piece (6). A centre piece bolted connection (11, 13) is thus opposite a bolted flange connection (10, 12) in each case.