Multi-Stage Ball Coupling for Reversible Drives With Low Vibration

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing flexible mechanical couplings for reversible drives face limitations in torsional flexibility, service life, and generate longitudinal loads, leading to excessive vibration and noise, making them unsuitable for applications like power trains and heavy-duty machinery where high starting loads and efficient power use are required.

Innovation Solution

A multi-stage flexible ball coupling design featuring end discs, intermediate discs, and a housing with arched ducts and coupler balls, filled with high-viscosity oil for lubrication and heat dissipation, providing high torsional flexibility and balanced operation with reduced mass moment of inertia, and adaptable for specific applications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If state-of-the-art flexible coupling designs are used, then torsional flexibility is provided, but service life is limited and longitudinal loads are generated

Engineering Contradiction:
Improvetorsional flexibilityVSAvoidservice life
Core Design Contradiction:
Stability of the object's compositionVSDuration of action of moving object

Solution Approach 1:

The coupling is divided into multiple discs (at least three discs including first and second discs) connected by multiple rows of elements (at least two rows). This segmentation allows each disc and element to share the mechanical loads, distributing wear and stress across multiple components rather than concentrating them in a single flexible element, thereby extending service life while maintaining torsional flexibility.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention replaces the traditional polymer or rubber flexible elements with a mechanical system consisting of multiple discs connected by coupling elements (such as balls or pins) moving in arched ducts. This mechanical substitution eliminates the degradation issues of polymeric materials while maintaining the desired torsional flexibility through the geometric design of the arched ducts.

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

2Adaptability or versatility

If traditional flexible coupling designs are used, then coupling function is provided, but longitudinal loads are generated causing vibration and noise

Engineering Contradiction:
Improvecoupling functionVSAvoidlongitudinal loads, vibration and noise
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The coupling elements move within arched ducts with specifically designed curved geometries. The arched shape of the ducts guides the coupling elements along a predetermined path that accommodates angular misalignment and torsional movements while preventing longitudinal separation between discs. This curved geometry converts potentially harmful longitudinal forces into beneficial radial and tangential forces, reducing vibration and noise.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The design ensures that the coupling elements experience balanced forces during operation by symmetric arrangement of multiple rows of elements and corresponding arched ducts. This equipotential configuration distributes loads evenly across all coupling elements, preventing any single element from generating excessive longitudinal forces that would cause vibration and noise.

Inventive Principle:
Principle #12Equipotentiality

3Force

If high torsional flexibility is required for reversible drives, then starting resistance is reduced, but steady-state motion fails to use full drive power

Engineering Contradiction:
Improvestarting resistanceVSAvoidpower utilization
Core Design Contradiction:
ForceVSUse of energy by moving object

Solution Approach 1:

The coupling provides variable flexibility characteristics through the geometric parameters of the arched ducts and the arrangement of coupling elements. During starting and reversing operations, the arched ducts allow greater element displacement, providing high torsional flexibility and low starting resistance. During steady-state motion, the coupling elements operate in a more constrained portion of the arched duct geometry, reducing flexibility to maintain better power transmission efficiency and utilization.

Inventive Principle:
Principle #35Parameter changes

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 achieves smooth start-ups, reduced starting resistance, and extended service life with minimal wear and noise, allowing better energy utilization and improved safety by maintaining dynamic balance and reducing surplus power requirements.

Implementation Method 1

The oil serves as a lubricant for the mating components such as the roller bearing 17, coupler balls 3, bushings 12 of the intermediate disc bearings as well as the sliding end bearing 13.

Methodology Applied
Scientific EffectLubrication: Lubrication

Implementation Method 2

the oil helps to dissipate the heat from the operating machinery and oil pumping. This is ensured by the notches 18 in the intermediate discs 4, which force the oil to move faster. The heat is then transferred through the housing 14

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

The heat is then transferred through the housing 14, advantageously made of Al alloy with good thermal conductivity.

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 4

The presence of oil inside the coupling plays the essential role of viscous damping of excessively fast ball movement within the arched ducts 10.

Methodology Applied
Scientific EffectViscous damping: Viscous Damping

Implementation Method 5

The coupler balls 3 have the capability to perform a rolling motion inside the arched ducts 10 serving as guides provided in all the discs.

Methodology Applied
Scientific EffectRolling motion: Roller

Data Source

PatentEP4206484B1A multi-stage flexible ball coupling, particularly for reversible drives
Publication Date: 2024.12.18 POLITECHNIKA SLASKA IM W PSTROWSKIEGO
  • EP4206484B1 patent drawingFigure 1
  • EP4206484B1 patent drawingFigure 2
  • EP4206484B1 patent drawingFigure 3

AI summary

A multi-stage flexible ball coupling, characterised in that it has end discs (2) and (6) a cover (9) and intermediate discs (4) housed in bearings on the shaft (1) coupled to each other with balls (3) placed in arched ducts (10) provided in the discs (2), (4) and (6), the end disc (6) and cover (9) being connected by a housing (14) and having reinforcing ribs (19). The interior is filled with liquid.