Author Topic: My perfect EV transmission  (Read 3350 times)

Offline mizlplix

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My perfect EV transmission
« on: February 01, 2013, 06:06:11 AM »
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If I had unlimited funds, and were free to choose, I would pick this for my transmission in an EV over 3,000 Lbs.

It weighs 37 Lbs, has low-high-reverse.  When in high gear, the transmission gears do not turn, the power flow is straight through! (cutting friction)    It can be shifted on-the-fly easily for a clutchless installation.

It is about $1,800.  BUT really a cool unit.

Miz

1930 Ford Speedster, AC50, full manual powerglide, 6.14gears, 38-130AH CALBs.

Offline Watts Up

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Re: My perfect EV transmission
« Reply #1 on: February 27, 2013, 06:31:09 AM »
Who is the transmission manufacurer, distributor? I have never seen it before. Do you know the specs and power limits?

Offline mizlplix

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Re: My perfect EV transmission
« Reply #2 on: February 27, 2013, 07:47:54 AM »
http://www.colemanracing.com/Lightweight-2-speed-Transmission-P6179.aspx

They use them on 700HP oval track racecars, I doubt if an EV will stress one too much.

Miz
1930 Ford Speedster, AC50, full manual powerglide, 6.14gears, 38-130AH CALBs.

Offline mizlplix

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Re: My perfect EV transmission
« Reply #3 on: March 29, 2013, 07:03:02 AM »
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           EV Transmission thoughts

It seems like everyone wants to build a Direct Drive EV.  It IS simpler and maybe cheaper, but it also has some problems.

The first ICE vehicles were converted horse drawn buggies with a 5-7 HP motor driving a single wheel.  They were simple, clunky, and usually went 5-10 MPH at best.

The roads were not good enough for even that speed.  Some of them had some steep hills and all usually forded a creek.

After driving the "car" the owner soon realized that sometimes they needed to slow down and travel over some rough spots or steep grades.  And the need for a transmission was born.


The first try at power transmission was usually a bicycle chain.  It served it's purpose and actually performed well.  When the need for another slower ratio appeared, it took the form of the gear planetary. (a system of gears where the power flow did not change direction, consisting of a sun, planets and a ring gear.)  By restraining the sun or the ring forced the power flow through different paths and those paths had differing ratios.

The planetary was quickly incorporated in the drive axle, making a nice compact unit. But, the need for another gear soon made that system expensive and obsolete.

Enter the spur geared power transmission (Manual transmission).  This could be built in any number of gear ratios, sizes and complexity.  There was, however, one drawback to it....greater friction and the resulting power loss. (which was covered up by adding a bigger engine.....)

It operated for 60 years or so with only minor updates.  The change from the "gear slider" type transmission to the "constant mesh" type being the most notable update.  The former shifted by sliding the gear along a shaft and meshing it with another gear, or sliding it back out of engagement.  The latter type used a gear set that every gear was in constant mesh (except reverse) and used a dog ring or synchroniser to slow them and lock them into the power flow.

Somewhere along the way someone decided to do away with shifting and make the car simpler to drive and the evolution of the automatic transmission began.

Our EV's have no need to disengage the power train at a stop like an ICE does.  We simply make everything stop. 

Our real problem starts when we need another gear due to a hill, freeway or carrying a load.  It is the same problem the ICE vehicles faced, but there is where the similarities stop.

-The heavier the vehicle, the more gears you will need.
-The more uneven the terrain, the more gears you will need.
-The wider speed range you drive, the more gears you will need.

Our solutions are somewhat different too.

(More later)
1930 Ford Speedster, AC50, full manual powerglide, 6.14gears, 38-130AH CALBs.

Offline few2many

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Re: My perfect EV transmission
« Reply #4 on: April 14, 2013, 02:47:04 PM »
Oops, just posted this in the powerglide thread. Here's a goodone, a little more affordable.http://www.circletracksupply.com/mitchell-bullet-tranny-fully-lightened-aluminum-2-speed-transmission.html

Offline mizlplix

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Re: My perfect EV transmission
« Reply #5 on: April 14, 2013, 03:40:38 PM »
Also answered in the other thread too.


Quote
That is just an old Saginaw 4 speed gutted.  Honestly it is a $400 core that has been gutted and some aluminum spacers installed.
You are still turning ALL the mainshaft and counter shaft gears all the time.  The rotating assy alone is 20Lbs.

The other transmission is 37 Lbs in total.  When It is in high, it is locked up straight through and the countershaft is not turning.

Big difference in friction for 50% more cash,

Miz

1930 Ford Speedster, AC50, full manual powerglide, 6.14gears, 38-130AH CALBs.