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

Um rolamento é um elemento mecânico que permite um movimento relativo entre duas partes, reduzindo o atrito e o desgaste do maquinário.
Também ajuda a distribuir cargas, que podem ser radiais, axiais ou uma combinação de ambas.
Os rolamentos de pivô suportam uma carga axial em um eixo rotativo. Eles podem ter uma superfície plana, cônica ou truncada.
Considere um rolamento de pivô plano submetido a uma carga axial com uma área total de rolamento de πR2.
A pressão uniforme no rolamento é expressa como a relação entre a carga e a área do rolamento.
Em seguida, considere um anel infinitesimal de raio r e espessura dr dentro da área de rolamento; a carga transmitida ao anel pode ser estimada.
Agora, a força de atrito que resiste ao deslizamento do anel atua tangencialmente no raio r.
Assim, calculando o momento do anel e integrando-o dentro dos limites radiais, pode-se estimar o momento do eixo, necessário para superar as forças de atrito.

<ol>
	<li>Hibbeler, R.C. (2016). Engenharia Mecânica \u2012 Estática e Dinâmica. Hoboken, Nova Jersey: Pearson Prentice Hall. Pág. 447.</li>
</ol>

rolamentos de pivô

Pivot Bearings

Em sistemas mecânicos, os rolamentos são cruciais para facilitar o movimento relativo entre dois componentes, minimizando o atrito e o desgaste. Eles ajudam a distribuir diferentes cargas (radial, axial ou uma combinação de ambas) entre as peças da máquina, garantindo um funcionamento suave e eficiente.

Um rolamento de pivô é um tipo especializado de rolamento projetado para suportar cargas axiais em um eixo rotativo. A superfície de rolamento, ou o pivô, é posicionada na extremidade de um eixo para suportar a carga axial. O pivô pode apresentar uma superfície plana, cônica ou truncada, dependendo da aplicação.

Em um rolamento de pivô plano, quando submetido a uma carga axial, a pressão uniforme exercida sobre o rolamento pode ser calculada como a razão entre a carga e a área de rolamento. Essa distribuição de pressão ajuda a minimizar o atrito e o desgaste na superfície de rolamento, contribuindo para um funcionamento mais eficiente e uma vida útil mais longa.

Para analisar ainda mais as forças atuando em um rolamento de pivô plano, podemos examinar um anel infinitesimal dentro da área de rolamento, com um raio r e espessura dr. A carga transmitida para esse anel pode ser estimada com base na distribuição de pressão na superfície de rolamento.

Conforme o eixo gira, as forças de atrito resistem ao deslizamento do anel e atuam tangencialmente no raio r. Ao calcular o momento do anel e integrá-lo dentro dos limites radiais, o momento do eixo pode ser determinado da seguinte forma:



<img alt="Equation 1" src="/files/ftp_upload/14324/14324_Equation_1v2.svg" style="text-align: center; height: 28px;" />



Este cálculo fornece informações valiosas sobre o desempenho e a eficiência do rolamento sob condições de carga variadas.

Os rolamentos de pivô são utilizados em uma ampla variedade de indústrias e sistemas mecânicos, devido à sua habilidade única de suportar cargas axiais em eixos rotativos. Esses componentes versáteis podem ser encontrados em máquinas rotativas, como turbinas, geradores, bombas e componentes automotivos, como sistemas de direção e conjuntos de transmissão. Além disso, os rolamentos de pivô, incluindo trens de pouso e superfícies de controle de voo, são fundamentais em aplicações aeroespaciais. Equipamentos industriais, como guindastes, guinchos e transportadores, também dependem de rolamentos de pivô para um funcionamento eficiente e desempenho confiável. Como resultado, o uso generalizado de rolamentos de pivô em vários setores destaca a importância deles na manutenção de sistemas mecânicos suaves e eficazes.

Rolamentos de Pivô

Em sistemas mecânicos, os rolamentos são cruciais para facilitar o movimento relativo entre dois componentes, minimizando o atrito e o desgaste. Eles ajudam ...

Education

JoVE Core

Mechanical Engineering

Engenharia Mecânica

Unit 1

Unidade 1

Friction

Atrito

KEY TERMS AND CONCEPTS

TERMOS-CHAVE E CONCEITOS

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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pivot bearings

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collar 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

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mechanical engineering

Axial Load Support in Pivot Bearings

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