Test you knowledge.

[narampa]

What is the one advantage planetary drive has over Spur Gear?
It is something overlooked now because they are so popular we never think of it anymore.

I was reading a bunch of old posts and there was one about planetary V/S spur gears and no body mentioned the obvious.

Have a go at it and see how you do!:thumbsup:

 

[mddorange]

When I work for Cat on their planetary tractor gears, they told me "size and stability." You get much more efficiency of energy throughput with a smaller gearbox.

 

[Dutch445]

planetary has multiple contact points through the gears that transfer the power,
therefore limiting the forces on any 1 gear and reducing chances of a broken tooth
which can lead to more broken parts.

 

[narampa]

When I work for Cat on their planetary tractor gears, they told me "size and stability." You get much more efficiency of energy throughput with a smaller gearbox.

Yes size is correct besides what else every body says.
On one of the other threads size was ommited.
Bulkhead systems are much larger.

 

[SPYDERLK]

Balanced loading.

 

[mddorange]

Yes size is correct besides what else every body says.
On one of the other threads size was ommited.
Bulkhead systems are much larger.

I guess I had an advantage since I used to get paid to know that.

 

[MinnesotaEric]

What is the one advantage planetary drive has over Spur Gear?
It is something overlooked now because they are so popular we never think of it anymore.

I was reading a bunch of old posts and there was one about planetary V/S spur gears and no body mentioned the obvious.

Have a go at it and see how you do!:thumbsup:

Increased contact points allowing even distribution of load and superior bearing distribution. Theoretically, allowing for longer life, smaller gears, and greater service life if all things are equal.

 

[Baby Grand]

Higher power density (HP/in^2) & (HP/lb).
Input shaft is co-linear with the output shaft.
Reaction loads resolve well, and in some cases they actually cancel, resulting in easier lives for the bearings.
2 ratios available for a given tooth count combination, depending on if you choose star or planet configuration.
With a little clever application of clutches (or brake bands) this can be used to create a 2 speed transmission.
Ratio of a single stage is limited, but you can compound 2 transmissions, in-line, in a very compact unit - this is how some rechargeable screwdrivers achieve a high torque/low bit speed with a high speed/low torque (compact) electric motor, all in a unit that isn't much wider than the hand grip.