2012 (Gen1) Transmission/Powertrain Question

[DrDeke]

Greetings,

 

I just bought a 2012 Fusion Hybrid and I have some questions about its powertrain; specifically, the transmission arrangement.

 

From driving the car and looking at the readouts, it feels to me almost like there is a clutch that can engage/disengage the ICE from the rest of the powertrain. But, from everything I have read, it sounds like this is not actually the case.

 

Do any of you know the answer to that specific question? Also, do any of you have a link to any documents which describe exactly how the Ford Gen1 transmission works? From what I understand, it is similar but not identical to the power-split device on a Prius (?).

 

Cheers,

Rusty

[lolder]

It's similar but not identical to the Prius. The layout and geometry is different but an engineering block diagram would be almost identical. Google "eCVT" transmissions which stands for electronic, continuously variable transmission. They are not the dual cone belted CVTs and are unique to Ford, Toyota and some Toyota licensed vehicles. There are no alternators, starters, clutches, torque converters, transmission bands or valves. There is one belt in the 2012 which only drives the engine ( ICE ) water pump. There are some electric coolant pumps. There are only gears engaging gears and bearings. There is hardly anything to wear. Brake pads can last over 100,000 miles with proper hybrid driving. The transmission is controlled by the smaller of two large, high voltage, 3 phase, synchronous permanent magnet motors which also starts the ICE. The larger motor is the main traction motor and also generates electricity which charges the high voltage battery ( HVB ) when braking. Both motors are enclosed in the eCVT which is one large unit. They are coolant cooled with a separate electric pump and radiator. Everything is blended together by software and power electronics. You don't have to know a thing. It's a seamless operation.

Until you get familiar, put the HVAC in "Auto" and set the temperature, put the car in "D" and go. I still do that after 6 years.

[DrDeke]

Oh, don't get me wrong, I love the car and it drives great! But I'm an engineer by training so I like to try to figure out what is going on when the car is in different modes. I re-read the "Graham's Toyota Prius" pages earlier today and it gave plausible answers to most of my questions, including the one about ICE RPM control here.

 

(Also, side note, I had to run a bunch of in-town errands this afternoon and ended up with 50.7 MPG at the end! I would have been lucky to hit 20 with that series of trips on my 2010 non-hybrid Fusion!)

Edited September 12, 2015 by DrDeke

[lolder]

It's an elegant design.

[bdginmo]

If you're an engineer then you'll definitely appreciate the mechanical simplicity of the eCVT transmission. I've seen these referred to as a power split device (PSD) as well. Do some googling and you'll find excellent videos, animations, and even simulations of how they work.