# EV Planetary Reduction Gear



## skooler (Mar 26, 2011)

Yes - take a look at the evtv store. There is one there.

Sent from my SM-N9005 using Tapatalk


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## AEM (Sep 12, 2014)

The Planetary gear on evtv is well made if somewhat expensive. but I had the idea based on what I've read here of using the front or rear Planetary Gearset out of a GM automatic modified for use with a high speed electric motor since it's a very common transmission .I doubt it would be an easy task though, though I have an uncle who is a mechanic who might be able to help if I decide to start such a project.


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## AEM (Sep 12, 2014)

What kind of bearings and lubrication would be needed to allow 12kRPM operation for these planetary


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## major (Apr 4, 2008)

AEM said:


> What kind of bearings and lubrication would be needed to allow 12kRPM operation for these planetary


That looks very much like a GM part which we used for a close coupled reducer at 12kRPM. Approximately 2:1 or 3:1 depending on whether output is planet carrier or ring gear. Found GM made a 5 planet version and we went to that. Not sure, but I think it was second from a vette tranny.

We lubed with ATF. We drilled the stub shafts for the needles in the planets and modded to get oil directly onto the needles. The main load bearings are designed in conjunction motor and load. Lube/cooling is provided to those as well as other gear meshes. 

We ended up with a great system but were at it for a year or two. Several "re-do's". That's how you learn. Need mechanical engineer who knows rotating equipment design and a guy who is a auto transmission rebuilder with a lot of experience is real helpful. Then you're looking at some special machining. And to do it right, testing.

On the other hand, the actual part you show in it's OEM configuration is probably good for 12kRPM for many miles. If it is a 2nd gear set, OEM duty cycle isn't that great. But your application is unknown. 

G' luck,

major


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## AEM (Sep 12, 2014)

The application would probably be for use with a Premium Efficient Induction Motor preferably copper bar if available. The motor would be oil cooled and it's rotor balanced for high rpm, a custom frame may be built for it to lighten it and house the Gearset. The motor and reduction would be placed in a Car I might be able to get in the future as a donor. The car though is a newer 2013 328i making it more difficult to convert. At the moment I'm researching and gaining some more experience by starting with a bike until I can get enough funding for a car.


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