Name: axial load support in pivot bearings
Uploaded: 2025-05-22T09:06:04.000Z
Duration: 1 min 23 s
Channel: JoVE

Un cuscinetto è un elemento meccanico che consente il movimento relativo tra due parti riducendo l'attrito e l'usura del macchinario.
Aiuta anche a distribuire i carichi, che possono essere radiali, assiali o una combinazione di entrambi.
I cuscinetti a perno supportano un carico assiale su un albero rotante. Possono avere una superficie piana, conica o tronca.
Si consideri un cuscinetto a perno piatto soggetto a un carico assiale con un'area portante totale di πR2.
La pressione uniforme sul cuscinetto è espressa come il rapporto tra il carico e l'area del cuscinetto.
Successivamente, si consideri un anello infinitesimale di raggio r e spessore dr all'interno dell'area del cuscinetto; il carico trasmesso all'anello può essere stimato.
Ora, la forza di attrito che resiste allo scorrimento dell'anello agisce tangenzialmente al raggio r.
Quindi, calcolando il momento dell'anello e integrandolo entro i limiti radiali, si può stimare il momento dell'albero, necessario per superare le forze di attrito.

<ol>
	<li>Hibbeler, R.C. (2016). Ingegneria Meccanica \u2012 Statica e Dinamica. Hoboken, New Jersey: Pearson Prentice Hall. Pagine 447.</li>
</ol>

cuscinetti di rotazione

Nei sistemi meccanici, i cuscinetti sono fondamentali per facilitare il movimento relativo tra due componenti riducendo al minimo l'attrito e l'usura. Essi aiutano a distribuire diverse cariche (radiali, assiali o una combinazione di entrambe) su parti di macchine, garantendo un'operazione fluida ed efficiente.

Un cuscinetto di rotazione è un tipo specializzato di cuscinetto, progettato per sostenere carichi assiali su un albero rotante. La superficie di appoggio, o il punto di rotazione, è posizionata all'estremità di un albero per sostenere la spinta assiale. La superficie di rotazione può essere piatta, conica o troncata a seconda dell'applicazione.

In un cuscinetto di rotazione piatto, quando sottoposto a un carico assiale, la pressione uniforme esercitata sul cuscinetto può essere calcolata come il rapporto tra il carico e l'area del cuscinetto. Questa distribuzione di pressione aiuta a ridurre l'attrito e l'usura sulla superficie del cuscinetto, contribuendo a un'operazione più efficiente e a una durata più lunga.

Per analizzare ulteriormente le forze che agiscono su un cuscinetto di rotazione piatto, possiamo esaminare un anello infinitesimale all'interno dell'area del cuscinetto, con un raggio r e uno spessore dr. Il carico trasmesso a questo anello può essere stimato in base alla distribuzione di pressione sulla superficie del cuscinetto.

Man mano che l'albero ruota, le forze di attrito resistono allo scivolamento dell'anello e agiscono tangenzialmente al raggio r. Calcolando il momento dell'anello e integrandolo entro i limiti radiali, il momento dell'albero può essere determinato come segue:

<img alt="Equation 1" src="/files/ftp_upload/14324/14324_Equation_1v2.svg" style="text-align: center; height: 28px;" />

Questa calcolo fornisce informazioni preziose sulle prestazioni e l'efficienza del cuscinetto in diverse condizioni di carico.

I cuscinetti di rotazione sono utilizzati in una vasta gamma di settori e sistemi meccanici grazie alla loro capacità unica di sostenere carichi assiali su alberi rotanti. Questi componenti versatili possono essere trovati in macchine rotanti come turbine, generatori, pompe e componenti automobilistici come sistemi di sterzo e assemblaggi di trasmissione. Inoltre, i cuscinetti di rotazione, compresi il carrello di atterraggio e le superfici di controllo di volo, sono fondamentali nelle applicazioni aerospaziali. Attrezzature industriali come gru, verricelli e nastri trasportatori si affidano anche ai cuscinetti di rotazione per un'operazione efficiente e prestazioni affidabili. Di conseguenza, l'ampio utilizzo dei cuscinetti di rotazione in vari settori sottolinea la loro importanza nel mantenimento di sistemi meccanici uniformi ed efficaci.

Cuscinetti di rotazione

Nei sistemi meccanici, i cuscinetti sono fondamentali per facilitare il movimento relativo tra due componenti, riducendo al minimo l'attrito e l'usura. Aiutano ...

Education

Didattica

JoVE Core

Mechanical Engineering

Ingegneria Meccanica

Unit 1

Unità 1

Friction

Attrito

KEY TERMS AND CONCEPTS

TERMINI E CONCETTI CHIAVE

Pivot Bearings

axial load support in pivot bearings

Pivot bearings support axial loads on a rotating shaft. A bearing helps two parts move relative to each other while reducing friction and wear. In this design, the pivot is placed at the end of the shaft to carry the axial thrust.

The pivot surface can be flat, conical, or truncated, depending on the application. In a flat pivot bearing, the axial load is spread over the bearing area. The pressure is uniform and can be found by dividing the load by the area.

To study the forces more closely, engineers can look at a tiny ring inside the bearing surface. This ring has a radius r and a small thickness dr. The load on the ring depends on the pressure across the bearing area.

As the shaft turns, friction acts on the ring and resists sliding. This force acts tangentially at radius r. By finding the moment of the ring and integrating across the radial limits, the moment of the shaft can be determined. This helps explain how the bearing performs under different load conditions.

Pivot bearings are used in many machines and industries. They appear in turbines, generators, pumps, steering systems, and transmission assemblies. They are also important in aerospace parts such as landing gear and flight control surfaces, as well as in cranes, winches, and conveyors.

Axial Load Support in Pivot Bearings

dry friction

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static friction

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kinetic friction

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characteristics of dry friction

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friction: problem solving

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wedges

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frictional forces on screws

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upward impending motion

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self-locking screw

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screw: problem solving

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frictional forces on flat belts

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flat belts: problem solving

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pivot bearings

Pivot bearings support axial loads on a rotating shaft. A bearing helps two parts move relative to each other while reducing friction and wear. In this design, the pivot is placed at the end of the shaft to carry the axial thrust. The pivot surface can be flat, conical, or truncated, depending on the application. In a flat pivot bearing, the axial load is spread over the bearing area. The pressure is uniform and can be found by dividing the load by the area. To study the forces more closely,...

collar bearings

Friction Torque in Collar Bearings

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journal bearings

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key terms and concepts

Learn how pivot bearings support axial loads on rotating shafts, reduce friction, and appear in turbines, generators, pumps, cars, aircraft, and industrial equipment.

Axial Load Support in Pivot Bearings | JoVE K12

JoVE Core Mechanical Engineering offers concise, easy-to-understand animated videos covering key topics such as equilibrium, forces, truss analysis, and structural mechanics. Explore their real-world applications, and witness these concepts in action through scientist-led experiments.

mechanical engineering

Axial Load Support in Pivot Bearings

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