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Fords new Hybrid Transaxle


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I don't know that 'base' is a best choice of words. It does share some parts with it, though.

 

From the slides...43 shared parts with the 6F and 143 or so brand new parts.

 

More less the same deal with the 1992 2v 4.6L Mod motor vs a 2012 5L 4V Coyote engine...the same...but different lol

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Thank you very much for posting. I've been trying to get a better idea of how the HF35 works.

 

If I understand the schematic on page 8 correctly, this might have some differences versus the AW Powersplit previously used but a lot of similarities. Difficult to tell. The AW uses a planetary gearset. The ring gear is powered by the traction motor/generator (MG2) which drives the wheels, the planet carrier is powered by the ICE, and the sun gear is connected to a second motor generator (MG1). Here's a really great demo:

 

http://eahart.com/prius/psd/

 

If I understand the schematic of the Ford design, it looks it will operate in a very similar manner, although the location of the components might be a bit different? The ICE powers the planet carrier, the smaller motor/generator powers the sun gear. The ring gear is connected to the output via Gear 2; on the same shaft the larger traction motor/generator is connected through Gear 4.

 

Not sure which components are shared with other Ford transmissions, but probably more in the differential area, since the whole planetary gearset and motors are unique.

 

Any transmission experts out there to give us more details??

Edited by Austin
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From the slides...43 shared parts with the 6F and 143 or so brand new parts.

 

More less the same deal with the 1992 2v 4.6L Mod motor vs a 2012 5L 4V Coyote engine...the same...but different lol

 

There might be some common components on the output side, but the basic design of the transmission is totally unique from a "normal" automatic 6-speed.

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...how the HF35 works.

 

If I understand the schematic on page 8 correctly, this might have some differences versus the AW Powersplit previously used but a lot of similarities. Difficult to tell. The AW uses a planetary gearset. The ring gear is powered by the traction motor/generator (MG2) which drives the wheels, the planet carrier is powered by the ICE, and the sun gear is connected to a second motor generator (MG1). Here's a really great demo:

 

http://eahart.com/prius/psd/

 

If I understand the schematic of the Ford design, it looks it will operate in a very similar manner, although the location of the components might be a bit different? The ICE powers the planet carrier, the smaller motor/generator powers the sun gear. The ring gear is connected to the output via Gear 2; on the same shaft the larger traction motor/generator is connected through Gear 4.

 

Not sure which components are shared with other Ford transmissions, but probably more in the differential area, since the whole planetary gearset and motors are unique.

 

Any transmission experts out there to give us more details??

not that I know what I'm talking about...

but

doesn't that sound something like the Volt?

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Thanks for posting. As you can see in the picture in the article you posted, the traction motor/generator and the smaller motor/generator are clearly shown side-by-side. In the previous AW box, they were located along the same axis as shown in this pic (this is a Prius, but Ford's is similar):

 

http://en.wikipedia.org/wiki/File:Toyota_electronic_continuously_variable_transmission_(2010-10-16)_03.jpg

 

I still haven't seen any specifics on Ford's electric motor capability. The EPA sticker on PHEV's is interesting. They show an electric-only range, and a mixed range of gas/electric until the battery is depleted. The PHEV Prius has an electric only range of 6 miles because there is a "hill" in the EPA test and the electric motor is not capable of putting the car over the hill without ICE assist. The mixed gas/electric rating for the Prius PHEV is 11 miles before the extra battery charge is depleted.

 

Anxious to see where the Energi models come out. Ford has just been releasing tidbits where the Energi will look good by comparison, but not the whole story yet. I suspect Ford's traction motor is more powerful which would enable you to keep the car in electric mode a bit more easily than the Prius PHEV. (But not similar to Volt which does not use the ICE at all as long as the battery has sufficient charge).

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The engine in the Volt only charges the battery and does not directly drive the wheels except at high speed (not sure exactly how that part works).

so the Volt's ICE engages the wheels directly "sometimes"

&

...Anxious to see where the Energi models come out. Ford has just been releasing tidbits where the Energi will look good by comparison, but not the whole story yet. I suspect Ford's traction motor is more powerful which would enable you to keep the car in electric mode a bit more easily than the Prius PHEV. (But not similar to Volt which does not use the ICE at all as long as the battery has sufficient charge).

it's my impression (easily wrong) that

WHEN the Volt's ICE drives the wheels is dependent on programming

ex: the 'Mountain Mode' that maintains a certain level of charge

(or like the Opel Ampera which can reserve its 'City Mode' electric capability until the driver wants/needs it)

&

for all I know,

(intermittently?) engages the 'wheels' as part of that mode regardless of speed...

Edited by 2b2
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Anyone know when Ford is going to switch over to the new HF35 transaxle? The recently (8/1) Fusion order guide still lists the eCVT for the hybrid.

 

Steven, the changeover to Ford's Gen III hybrid system with the new transmission and lithium batteries starts with the 2013 Fusion and C-Max's. The Energi PHEV's also use the same box. Even though the transmission has changed, both the prior AW box and the new Ford box are "eCVT's." -- they vary ratios through the use of a planetary gear set interacting with the electric motor/generators.

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so the Volt's ICE engages the wheels directly "sometimes"

&

it's my impression (easily wrong) that

WHEN the Volt's ICE drives the wheels is dependent on programming

ex: the 'Mountain Mode' that maintains a certain level of charge

(or like the Opel Ampera which can reserve its 'City Mode' electric capability until the driver wants/needs it)

&

for all I know,

(intermittently?) engages the 'wheels' as part of that mode regardless of speed...

 

Basically for the Volt:

 

1. The system first depletes the charge in the battery. At this point, the Volt drives on electric only, and the ICE does not come on at all. As you mention, however, I believe you are correct that the Volt has a driver selection that can override the system and turn on the ICE earlier to preserve the battery charge. But the default is electric only for the first 40 miles or so on the battery.

 

2. After the charge in the battery is depleted, the Volt turns into a series hybrid. The ICE powers a generator which in turn powers the traction motor.

 

3. In some circumstances (higher speeds), clutches engage and the Volt can be powered directly by the ICE.

 

Ford's system is another version of the powersplit where the ICE and electric motor/generators interreact and the relationship can be adjusted through the powertrain calibration. Generally, the driver will leave it up to the experts who calibrated the vehicle. However, the Plug In Prius and the Ford Energi's both have driver selections that will tell the car to, say, stay on electric only at first. But this only goes so far -- if the power requirement is too high, like accelerating swiftly on an entrance ramp, the ICE will come on anyway.

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Basically for the Volt:

 

1. The system first depletes the charge in the battery. At this point, the Volt drives on electric only, and the ICE does not come on at all. As you mention, however, I believe you are correct that the Volt has a driver selection that can override the system and turn on the ICE earlier to preserve the battery charge. But the default is electric only for the first 40 miles or so on the battery.

 

2. After the charge in the battery is depleted, the Volt turns into a series hybrid. The ICE powers a generator which in turn powers the traction motor.

 

3. In some circumstances (higher speeds), clutches engage and the Volt can be powered directly by the ICE.

 

Ford's system is another version of the powersplit where the ICE and electric motor/generators interreact and the relationship can be adjusted through the powertrain calibration. Generally, the driver will leave it up to the experts who calibrated the vehicle. However, the Plug In Prius and the Ford Energi's both have driver selections that will tell the car to, say, stay on electric only at first. But this only goes so far -- if the power requirement is too high, like accelerating swiftly on an entrance ramp, the ICE will come on anyway.

 

I think the only reason it uses the ICE directly is that the generator cannot supply enough electricity to drive the wheels on electricity alone. That's the drawback of the Volt architecture - you lose energy when you convert the ICE output to electricity and then convert it back to mechanical energy through the electric motors. It's more efficient to drive the wheels directly.

 

That's why the Volt only gets 37 mpg once the battery is depleted whereas the Fusion Energi should get close to the Fusion Hybrid (40's).

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The Volt switches to direct ICE drive under SOME circumstances over about 70mph. This actually has nothing to do with sufficent electricity to drive the wheels but rather that at certain speeds and loads, it is more efficent to do direct drive rather than electrical drive. Under other conditions, the Volt will stay on pure electric drive up to 100mph... It's actually a very elegant system.

 

I think the only reason it uses the ICE directly is that the generator cannot supply enough electricity to drive the wheels on electricity alone.

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Under other conditions, the Volt will stay on pure electric drive up to 100mph... It's actually a very elegant system.

 

Just what would those "other conditions" be, that would allow the Volt to "stay on pure electric drive up to 100mph"? Driving off a cliff? :hysterical:

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There is a public paper that details it all - more than I can hope to remember - but basically it has to do with the level of the battery charge and level of acceleration commanded.

 

Just what would those "other conditions" be, that would allow the Volt to "stay on pure electric drive up to 100mph"? Driving off a cliff? :hysterical:

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It's actually a very elegant system.

"de gustibus non est disputandum" notwithstanding, I would not call the Volt system elegant.

 

In gas-only mode, the system is comparable to occasions when I plug a AC inverter into my car's outlet, and then plug a DC adapter into the AC inverter to charge my laptop. I would under no circumstances describe that as an elegant way to charge my laptop.

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The Volt switches to direct ICE drive under SOME circumstances over about 70mph. This actually has nothing to do with sufficent electricity to drive the wheels but rather that at certain speeds and loads, it is more efficent to do direct drive rather than electrical drive. Under other conditions, the Volt will stay on pure electric drive up to 100mph... It's actually a very elegant system.

 

Above 70 mph the ICE is always engaged and provides some motive force through the secondary motor/generator.

 

A traditional plug-in hybrid is way more efficient with the ICE always powering the drivetrain directly when it's running rather than indirectly through a generator.

 

Where the Volt could shine is the use of a more efficient power source (totally disconnected from the drivetrain) that can overcome the energy conversion losses yielding better MPG. This energy source could be swapped out, upgraded or run in parallel to provide more electricity.

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It's possible that a turbine would be a better energy source, although even there you're looking at such a wide variety of power requirements during a 'typical drive' vs., say, the fairly consistent power requirements of, say, a locomotive engine.

 

I was thinking a small turbo diesel or some future technology like a hydrogen fuel cell. Since the engine would not be constrained by the operating parameters of a transmission it really opens up the options.

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I was thinking a small turbo diesel or some future technology like a hydrogen fuel cell. Since the engine would not be constrained by the operating parameters of a transmission it really opens up the options.

 

And it could be run in the most efficient portion of its power band 99% of the time.

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