Mechanical advantage planetary gear help

AI Thread Summary
The discussion centers on the mechanics of planetary gears, specifically the relationship between gear ratio, output speed, and torque. A gear ratio of 3:1 means that if the input is 600 rpm, the output will indeed be 1800 rpm. However, while the output speed increases, the torque does not simply increase proportionally due to the mechanical advantage provided by the larger planetary gears. The torque generated against the planetary gear will be influenced by the load, and the mechanical advantage helps manage this torque. Ultimately, the interaction between speed and torque in a planetary gear system is complex and requires careful consideration of load conditions.
njguy
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First of all, I am a newly registered user, so thanks for any help guys.

I am confused with the concept of planetary gears. Let's say there is an rpm applied to a planetary gear of 600 rpm and the gear ratio is 3:1. So the output of the planetary gear then spins 1800 rpm (600 * 3). Now my question is a bit confusing, since there is a higher gear ratio the output will be spinning faster, thus generating more torque. However the planetary gear has mechanical advantage, since the outer gears(planets) are 3 times the size of the inner gear(sun). So do they essentially cancel out? If this isn't clear please let me know. Thanks guys.
 
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are you sure output is spining faster, will produce more torque??
what exactly do you mean by "canceling out"?
 
vishal007win said:
are you sure output is spining faster, will produce more torque??
what exactly do you mean by "canceling out"?

Not the output will generate more torque, but more toque will be generated against the planetary gear since the output is spinning the load faster. But will that negative torque against the gear be taken up by the mechanical advantage of the planetary gears?

Planetary gears = 3 * size of sun, since gear ratio is 3:1 thus sun spins 3* as fast

Since sun spins 3 times as fast, what would happen to the initial rpm under load?
 
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