Variable Planetary Transmission

That only works on a large scale like a locomotive.

My point is you can get better efficiency out of an electric motor if you keep it in its optimal RPM band, which would help with one of their major shortcomings right now: their range.

>My point is you can get better efficiency out of an electric motor if you keep it in its optimal RPM band,
you can stay in that band from 40-60mph

Electric motors are not equivalent to IC engines. An ICE's optimal torque and efficiency are tied to rpm, whereas an electric motor's efficiency is tied to it's load. Why add a transmission for extra complexity and weight, when you can just engineer the motor to the appropriate size and specs to begin with?

>what is city driving

Cool, guess what really fucks up your range? Low-speed start-stop city driving, which isn't at 40-60mph.

because city driving is different than freeway cruising?

that's not really the way it works user, you should not be significantly inefficient with an electric motor at low speeds, the draw is based on how much you are working the engine it's not nearly as rpm based as a gas fed engine.

it's almost for sure going to be more trouble than it's worth to put a tranny in one vs. just carefully designing it to be efficient between 0 and 70mph

Exactly. When you're accelerating your motor has a high load, which is when it's most efficient, and with regenerative braking some of that energy is recaptured, increasing efficiency even more. A transmission accomplishes nothing.

How the fuck can you keep a car going 40-60 mph in varying conditions? Weather, traffic, road hazards, no fucking way you can maintain that condition save for highway driving.
Even ICE can get more than 40% thermal efficiency just in highway driving. Its literally the auto industry's panacea for EPA fuel efficiency rules.

>Cool, guess what really fucks up your range? Low-speed start-stop city driving, which isn't at 40-60mph.
with a gas engine not with an electric motor

do you know how electricity works?

there is no carburetor

And guess what the vast majority of electric cars are doing: city driving, becuase of customer range anxiety.
Are you not coming to grips with the real issue here?

How the fuck is the electric car going to get up to 40-60 mph?By frictionless surfaces that allow it with just inertia to maintain 40mph from rest?

Don't bother explaining this to dumb boomers who can't let go of the past, there's a good chance they like using a number stick and are against autonomous cars too

>And guess what the vast majority of electric cars are doing: city driving, becuase of customer range anxiety.
>Are you not coming to grips with the real issue here?
tell me how much more efficient you think an electric motor with a tranny would be during city driving, why you think that, and why you think engineers don't put 8speed trannys in electric cars

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user is confusing efficiency with power consumption
Accelerating a 2000kg vehicle from a dead stop takes a lot of energy. Even at 100% efficiency you're still consuming more energy per mile in stop and go traffic than cruising at speed

The vast majority of people do city driving because the vast majority of people live in cities. Range anxiety comes from the energy density of batteries vs liquid fuel

>How the fuck is the electric car going to get up to 40-60 mph?By frictionless surfaces that allow it with just inertia to maintain 40mph from rest?
are you high

i don't see how a tranny is going to change that

It won't.

Advantages for merely city driving:
1. can climb hills without increasing electrical drain
2. overdrive or alternate drive ratio to extend range for longer trips
3. more toque for towing loads, allows much more lower range torque with specific gearing

Why its not adopted :
1. Tesla engineers are brainlets and couldn't figure out how to get a 2-speed working properly so they skipped it and tried to market the Model S (and 3 series) as a "performance" vehicle citing its high acceleration performance from a stop- Kreisel Electric has a 4 speed electrical car transmission ideal for use in small to medium size delivery trucks or larger trucks and buses up to 15 tons. Has been in use in electric vehicles for almost 3 years now.

>3. more toque for towing loads,
Electric motors produce 100% torque at 0 rpm

i don't think you know what you are talking about

1. Not how that works
2. Also not how that works
3. Are you sure you're not talking about internal combustion engines? Because this is 100% wrong

Not sure if electric cars use three phase motors, but if they do, you can switch between star and delta connections depending of the speed you need.

electric cars are gay tbqh

man everytime i see some faggot ass candy man driving an electric car you can almost look into his life and see he does absolutely nothing of value

>did you know that Tesla accelarates just as fast as a Bugatti?
>ugh why would you drive manual, didn't you know that it's obsolete?
>Internal Combustion Engines are bad for the environment y'know?

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Are you fucking high? No, you just don't know what you're talking about. Electric motors have an extremely minimal change in efficiency across a very wide rpm range, and the changes in loss are more to do with bearings than the electromagnetic bits. Gearing adds loss, and switchable transmissions add even more than a fixed setup. You'd chew through any small gain in efficiency from running the motor optimally in transmission loss and added weight.
The best thing to do is design the motor, bearings, and housing to match the rpm range required, and add a single fixed gear if necessary. Vehicle engineers aren't retarded, and electric range is getting really competitive. Did you really think the electric car manufacturers have no idea what they're doing?

This is how some hybrid electric cars work today.

That's true, but regen braking can aid enormously in stop and go, to the point where electric cars are often rated for better eMPG in city driving. Highway driving is at higher speed, which means more friction losses, which you can't do much more about than what's already been done.

>Advantages
None of those change with different gearing. Electric motors have the most torque at stall, so you just run it slower to get more torque. And trying to make a Tesla more torquey is a fools errand, the wheels and frame can barely handle what the motors can do.
>Elon's engineers can land a rocket booster on its tail but can't figure out a two speed transmission.
What the fuck.
Okay, you don't ever see variable transmissions on industrial systems powered by electric motor for a reason: It's retarded to do. If you want variable output, you use a VFD or some PWM shit, which is what electric cars do. It's lighter, more efficient, more reliable, and cheaper.

>extremely minimal change in efficiency across a very wide rpm range
if you ever used a well pump you'd know that is totally not true

I've used many well pumps. 90% of the water I've used in my life has come from them. I've installed them and serviced them, and I have no idea what you're talking about.

check out the electricity usage vs gpm chart

Oh okay, that's because a well pump is a shitty single phase motor. Single phase motors have a definite ideal load, unlike three phase motors and advanced brushless DC motors. It's not the rpm that matters so much as the load resistance, so gearing doesn't help at all.

low energy post but yeah this desu

i have no clue what I'm talking about, but wouldn't reduction gears help with keeping motors smaller while helping balance he wider required torque range for moving heavy loads?

not really necessary for current iterations of normal electric cars though, at least i would imagine

>transmission
Laughs in electric cars

Cagers btfo!

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not true, Toyota has been shipping an electric CVT since 2004 and it works fine
en.wikipedia.org/wiki/Hybrid_Synergy_Drive

What if...I ran an EV with a gas powered generator?

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you lose the efficiency in the transmission ...

that's a hybrid

That's how trains work, just generally diesel instead
en.wikipedia.org/wiki/Diesel–electric_transmission

en.wikipedia.org/wiki/Hybrid_Synergy_Drive

Original tesla roadster had 2 speed trans.