Power Transmission
Custom shaft couplings can be useful for applications where standard products cannot be accommodated. They also offer scope to enhance the design and deliver additional benefits, including improved performance and lower overall costs. Paul Stevens investigates what can be achieved with the current generation of custom shaft couplings.
Les accouplements d’arbres spécialisés trouvent toute leur utilité lorsque l’application n’autorise pas un produit standard. Outre des possibilités d’amélioration de la conception, ils apportent des avantages supplémentaires, incluant une performance supérieure et des coûts d’ensemble réduits. Paul Stevens examine les résultats offerts par la nouvelle génération d’accouplements d’arbres spécialisés.
Für Anwendungen, bei denen serienmäßige Produkte nicht eingesetzt werden können, sind anwendungsspezifische Wellenkupplungen oft die ideale Lösung. Sie schaffen außerdem Spielraum zur Verbesserung der Konstruktion und bieten zusätzliche Vorteile, wie bessere Leistung und reduzierte Gesamtkosten. Paul Stevens recherchiert, was mit der neuesten Generation von
anwendungsspezifischen Wellenkupplungen erreicht werden kann.
Fig. 1. Redesigned components can perform coupling functions and also adopt features from other parts in the assembly.
How to maximise the benefits of custom couplings
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Fig. 2. Alternative mounting arrangements can be machined on each end of the coupling.
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hen designing a machine, product or mechanism with rotating parts it is very easy to locate two components or shafts and simply note that a
shaft coupling is required. Actually specifying the coupling is often left until late in the project, at which point the designer might discover that, for whatever reason, standard products are unsuitable. It is also not uncommon for shaft couplings to
fail in service, perhaps because they were incorrectly specified or because they are subjected to loads that were not foreseen during the design process, and sometimes it is necessary to introduce a compliant coupling to overcome a problem that is causing another component to fail. Fortunately, many of the manufacturers of shaft couplings are able to work with designers to create bespoke couplings that will function as required, and sometimes the ‘coupling’ component can be designed to
incorporate functions that were to be performed by other components, thereby simplifying the design, as well as potentially cutting cost, reducing weight and improving reliability and serviceability. Abssac manufactures and sells an extensive
range of standard couplings, including bellows couplings (electrodeposited and hydro-formed), disc couplings (for standard and servo applications), gear shaft couplings, helical couplings, X-slot couplings, jaw couplings, Sure-Flex elastomeric couplings, rigid couplings and universal joints. In addition, the company designs and manufactures special products that are either variations of these standard shaft couplings or more complex components that integrate several functions. For example, the basic dimensions of a helical
coupling can be modified to suit the application’s torque and compliance specifications, or alternative mounting arrangements can be incorporated to suit the customer’s requirements. In many cases the final coupling-based component is an amalgamation of separate parts including items such as external gears, splines, threads and tangs (Fig. 1). Abssac is so confident in its ability to create successful customised products that it often offers a free sample for test and evaluation purposes. The performance characteristics of a helical
flexure are determined by six major factors: outside diameter, inside diameter, coil thickness, material,
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