WEBVTT

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O joo de enrenaens planetárias

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também conecido como,

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a enrenaens epicíclica

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é uma das

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mais importantes

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invençoes da enenaria.

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Sao ótimos mecanismos

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para variaçao de velocidade e torque

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e sao frequentemente usados

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em automóveis como parte vital

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das transmissoes automáticas.

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Vamos explorar os seredos

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das enrenaens

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neste vídeo!

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O joo de enrenaens

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tem 4 partes principais:

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a enrenaem solar,

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as portas planetárias,

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a enrenaem anelar,

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e o braço.

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Podemos ver que elas

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podem irar rapidamente,

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ou mais de devaar,

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até mesmo em marca reversa.

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Mas, como isso acontece?

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Voce será capaz

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de prever o movimento

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das enrenaens por comcompleto,

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se entender

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um fato simples.

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quando duas enrenaens

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esao se movendo, veja,

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elas devem estar na

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mesma velocidade

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do eixo.

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Isso sinifica

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que a velocidade da enrenaem A

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deve ser a mesma

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que a da enrenaem B,

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no seu ponto de encontro.

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A velocidade tem que ser

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a mesma, ou

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os dentes da enrenaem

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irao encontrar uns aous outros

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desta forma.

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Tornando a situaçao impossível.

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Aplicando esta correçao

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nas enrenaens planetárias,

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voce poderá ver

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como a variaçao velocidade

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será alcançada,

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No momento a enrenaem solar

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está na posiçao imóvel

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e a enrenaem solar ira.

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Pense no que acontece

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as enrenaens planetárias.

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No ponto A

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a enrenaem solar

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deve estar a uma determinada velocidade

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e no ponto B

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a velocidade deverá ser zero,

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pois a enrenaem anelar ou externa

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está estacionada ou imóvel.

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No entanto,

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como estas duas situaçoes

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sao possíveis ao mesmo tempo?

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Só á uma explicaçao,

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a enrenaem planeta

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deverá irar e ao mesmo tempo virar!

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A rotaçao irá produzir

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velocidades em direçoes opostos

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nos pontos de cima e de baixo,

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veja,

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enquanto, a virada

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produz velocidades unidirecionais.

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Em cima, as velocidades

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de rtoaçao e virada

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estao em direçoes opostas,

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assim, a velocidade do

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ponto B é zero.

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Em baixo.

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elas se somam.

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Nas pequenas

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enrenaens planetárias

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sao forçadas a virar

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para compensar a exiencia

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da velocidade encontrada.

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Quando o braço é liado

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as enrenaens planetárias

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ele irá virar juntamente com

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as enrenaens planetas.

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Aora, vejamos o que acontece

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quando a enrenaem solar

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está travada

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e a enrenaem anelar

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é irada.

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O exato oposto ao caso anterior.

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No ponto interno

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da enrenaem planeta

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