Single Speed Transmission

[evluv]

The Ford Focus Electric comes with a single speed transmission - or does it?

This picture from Ford's website clearly shows a 'low' and a 'drive' setting, not to mention reverse. Does reverse count as a speed? Low does for sure. To me it looks like the Ford Focus Electric has a 2 speed transmission.

Ford states the transmission is built specifically to handle the high rpms that an electric motor puts out. Being single speed, the Ford Focus Electric will have quick responsiveness and silky smooth acceleration... oh and 'no-compromise driving fun'

 

[toffty]

I'm going to assume that it works like the Prius - except reverse which'll probably be different

-Drive - One speed transmission
-Low - Same gear set but when your foot is off the A peddle your regenerate evergy faster than when in drive. This is great when going down hill: less wear on your brakes and you get more 'free' energy in your battery.
-Reverse - The same gear set is used, all you do is reverse the flow of electricity to make the electro-magnetic field point in the other direction in the motor. There's probably a speed limit in the software to prevent you from going 60 in reverse

 

[california]

On the Leaf there is a separate control setting for extra re-generative power, or economy mode I think it's called, so that you can turn it off if you want a smoother ride.

Is that what you mean by the 'low' setting in the Focus EV?

 

[jeff_h]

I have a Fusion Hybrid with ECVT, which also has a 'D' and 'L' although I've never used the 'L' at all. Below is what the owner's manual says about low gear:


"Low Gear: L (Low gear) is designed to mimic the enhanced engine braking available in non-hybrid vehicles. L (Low gear) will produce high engine speeds to provide necessary engine braking. This is normal and will not damage your vehicle. In L (Low gear) the gas engine will remain on more often than in D (Drive gear)."

 

[california]

Thanks Jeff - sure works nice to see what a Ford Fusion manual says about the D and L on the shifter, which we should be able to assume it means the same on the Ford Focus Electric shifter?!? I've noticed a lot of assuming about the Focus EV going on in this forum!

 

[jeff_h]

I've noticed a lot of assuming about the Focus EV going on in this forum!

Unfortunately this is all we have at the time... however once a little more exposure is made, I hope others will post more info to include pics etc. I sure will if I find one at a dealer in DC or Richmond, I'm anxious to check it out.

 

[california]

Unfortunately this is all we have at the time... however once a little more exposure is made, I hope others will post more info to include pics etc. I sure will if I find one at a dealer in DC or Richmond, I'm anxious to check it out.

I second that! More info already, Ford!

 

[fordfocuselectric]

According to the Ford Focus Electric Owner's Manual the D stands for Drive, and the L stands for low - which is the same as drive but provides maximum motor braking.

Apparently it's not intended for use under extended or normal driving conditions and results in less miles per charge.

It must do more than provide maximum motor braking, because that should just create more regen? Unless of course it slows the vehicle as soon as you let off the accelerator so there's no real coasting option?

 

[Rwbill]

Ford does refer to drivers having to adjust to the regen mode. Sometimes it reads as if the motor engages the wheels and would seem to slow down the car, which would not make sense. It may put power back into the battery but that would accomplish little or be counter productive to merely needing to coast for a few seconds. I'll need to work this out after I get my FFE.

 

[mrpalerider]

I'm surprised their not putting transmissions in these things, they'd get better mileage/per charge if they added gearing to reduce the motor load at low speed. No benefit to the motor as a DC motor specifically wound can produce constant torque at a broad range of speeds, but it would definitely lighten the load on the batteries. I could see that in the future when we start seeing high performance EV sport cars.

http://www.myfocuselectric.com/forum/viewtopic.php?f=7&t=587

Looks as though this posting by Rwbill shows that the FFE has a standard automotive transmission that is 'single speed'

 

[dwf123]

I now have 3500+ miles on my FFE. For most of my life I have driven a variety of manual transmissions and enjoy the driving control a transmission provides. Technically I do not know how this transmission operates. I read it is not a transmission but a direct drive with some kind of electric control to modify the motors RPM speed. Forward and reverse are achieved by simply reversing the polarity of the motor. Low engages the motor in regeneration. But, I am not an engineer so I am just guessing.

I commute 40 miles one way on 4 lane US Route 1. It has two large bridges, one 2 1/2 miles long and 10 stories high the other 1 1/2 miles long and 7 stories high, 17 stop lights and I achieve an average speed of 47 miles per hour.

My technique for driving has adjusted to the transmission. Neutral is literally free wheeling. Going down hill coasting is awesome. (In older automatic cars driving in neutral was not recommended. I hope that is not true anymore!???) Drive has a noticeable slowing effect when you are not pressing on the accelerator. Low is as good as stepping on your brakes. The combination of these three "gears" is lots of fun.

So for my commute and when I am in the midst of traffic, I am constantly shifting from drive to neutral if I want to coast down the back side of the bridges and then if I need to slow down, I'll go back to drive, and if a light changes and I need to stop, I drop to low.

It is very effective and saves wear and tear on the brakes and appears to improve my efficiency. According to MyFordMobile and for the 3500+ miles, I am averaging 250 watts per mile which is approximently $0.0375 per mile at my rate of $0.15 per kWH. In my gasser I spent $0.146 per mile at $3.65 per gallon of gas. That is a 75% savings over the cost of gas.

 

[Charged Up]

So for my commute and when I am in the midst of traffic, I am constantly shifting from drive to neutral if I want to coast down the back side of the bridges and then if I need to slow down, I'll go back to drive, and if a light changes and I need to stop, I drop to low.

It is very effective and saves wear and tear on the brakes and appears to improve my efficiency.

Wood, BINGO! You are exactly right. In 3500 miles or probably less you quickly figured out that basically you DO NOT WANT AUTOMATIC REGEN.

The OEMs put this auto regen when you lift off the acclerator pedal to replicate the feel of a gasser. Well a gasser does that because of engine braking and because the brakes are literally engaged all the time. We have neither in an EV.

I play the D to N shift games as well but eventually you realize "hey why don't they just let me decide when I want regen with the brake pedal...duh!"

Or let the amount of auto regen in D be user selectable.

There are many, many instances where you are having to shift into N to be more efficient. One of the most common is when trying to time your arrival at a light just as it turns green. In a gasser of course most people drive like hell to race up to the red light and then ride the brakes hard to a stop.

In an EV most people gravitate to timing the arrival with the light turning green if possible, or at least not wasting energy racing to the light then riding the brakes.

I found that if a began coasting in D, many people would be on me before they realized and be aggravated. However, if I shift into N the decel is so moderate that they have time to decide to go around or slow with me without getting aggravated. So I try to do the former.

I wish someone would get it this point through the the thick skulls of the knucklhead engineers, people don't want their EVs to replicate the "drag" of their gassers automatically.

If it was possible to hack my Volt and the FFE ( when it arrives) to have zero auto regen in D, I would definitely do it.

And that might be a possibility in the near future. Interesting blurb on EVTV about a can bus interface that is in the works.

 

[dwf123]

BINGO! You are exactly right

Leave it to a "techie" to figure out the rational... Thanks Marc! I could not understand why Drive slowed the car down so much. It is almost dangerous. So both Drive and Low are forms of regen.

Neutral is sweet. The car justs glides along... I also use it to help pull up to lights or coast around curves. The regen thing is a great idea but, practically speaking, adds very little mileage. My app tells me I have a 98% braking regen and have added 8 miles in battery charge after 3500+ miles of driving. I am believing that coasting has depleted less then 8 miles on the battery.

Message me if you find a way to wipeout regen in Drive. And, thanks so much for confirming my experience. One of the big advantages to these forums is confirming and/or warning people about their ideas and practices.

PS.... When is your car arriving???

 

[Fluke]

I had heard that Ford's philosophy on regeneration was to keep it with the brake pedal. Unfortunately, as you have seen they did not do that. In fact, the FFE has stronger regeneration in "D" than the Volt does. In "L", the Volt's regeneration is stronger. In either car, you can get to a neutral coasting point by modulating the accelerator pedal - the Volt provides the power flow diagram that allows you to see this happening. I agree that in "D" the FFE has too much regeneration. With the Volt moderate hills could be driven by lifting off the accelerator and coasting down the hill in "D" to pick up a little battery charge when it made sense. On the same hills in the FFE, I must either feather the accelerator pedal or put the car in "N" in order to maintain the speed limit. Interestingly, the Volt also coasts longer in "N" than the FFE does - I believe it could be due to the larger tires on the FFE.

With a little over 1500 miles on my FFE, I've been able to achieve 193 Wh/mi average consumption at the car. I keep track of the consumption of the charging circuit going to the EVSE, and based on this data the actual consumption at the wall is 265 Wh/mi. There are significant losses in the charging process, but I did not realize that the myfordmobile.com site does not accurately account individual trip miles so the 265 Wh/mi number is inflated. I'm now tracking daily mileage by hand to get to a more accurate at the wall number.

As a point of comparison, my Volt has an average at the wall consumption of 285 Wh/mi (and has used around 5 gallons of gas) over 13,500 miles during the last year plus of driving.

 

[felkster]

I personally find the FFE regen in D mode to be on the lower end of the hybrid/EV spectrum. My Escape Hybrid has a stronger regen drag in drive, as has the Leaf, Prius, and Civic Hybrid I've driven. I didn't drive a Volt beyond a single test drive, to I'll trust you guys on that.

The regen I think is a matter of preference. I'm with most of you in preferring little to no regen during Drive mode. I say save the strong regen for shifting into Low or pushing on the brakes. Some people LOVE strong regen. All reviews/reports from Tesla Model S drives is that you barely need to use the brakes because the default regen is so high. I would love to have a setting, but that just seems like one more computer setting to over-complicate the car for users.

 

[Charged Up]

In either car, you can get to a neutral coasting point by modulating the accelerator pedal - the Volt provides the power flow diagram that allows you to see this happening.

I disagree. In the Volt, when in D, no matter how much play with the accelerator, you are either pulling from the battery or you are in regen.

The power flow diagram is fun, but not accurate. Put your Volt in N and put up the diagram. Behold it still shows juice going from the battery to the motor.

Interestingly, the Volt also coasts longer in "N" than the FFE does - I believe it could be due to the larger tires on the FFE.

That is discouraging to hear, are you quite certain? The Volt has electric brakes which unlike hydraulic brakes do not engage the rotor full time... surely Ford didn't cheap out just leave the hydraulic brakes in did they?

 

[Charged Up]

I'm surprised their not putting transmissions in these things, they'd get better mileage/per charge if they added gearing to reduce the motor load at low speed.

Not necessarily. In general, electric motors are more efficient at higher RPMs. Yes you have full torque at 0 rpm, but the motor is least efficient at lower RPMs. As the torque falls off at higher RPMs the efficiency goes up.

Adding gears might give better acceleration at various speed bands, but would likely lower efficiency.

 

[Trielectric]

"Magna" appears to be the manufacurer of the FFE Inverter, Motor and Transmission. It looks like their Manufacturing plant did not open until April 2012 thus the holdup on delivering new FFEs until May. The transaxle casing appears to be on the drivers side of the car bolted to the motor housing. Now if we can find a picture of what's inside that case.

News release.
http://www.magnaecar.com/media/press-releases-news/news-page/2012/04/16/news-release---magna-e-car-systems-debuts-new-manufacturing-facility

Pictures.
http://www.magnaecar.com/capabilities/hybrid-electric-vehicles-systems/products-services/individual-components

 

[Trielectric]

An early pdf of Fords (Electrification_1[1].pdf) states the "transmission is a single-speed unit with a 5.4:1 reduction.". Magna States the motor is good for 10,000RPM (arravt027_ape_peaslee_2012_p[1].pdf). If this is the reduction we ended up with
our FFE's should have an RPM limited top speed of ~143mph(disregarding aero drag). It could be, but it doesn't seem likley they would have limited us to 85mph, unless there are some electrical components that cannot handle the full speed load.
There are some cut away photos of the transmission that were taken at shows around the country in 2010. One web site is " http://www.engadget.com/photos/ford-focus-electric-motor/#3774179 ". This clearly shows the small black drive gear off the motor and the shiny big carrier assy drive gear for the axle spider gears. Another view in an Edmund video shows a third gear that appears to be the gear driving the big shiny axle carrier assy gear. But so far no clear photos of the tranmission internal shift mechanism that hooks up to the external shift cable at the top of the transmission and no view of the actual gear the motor gear is engaged with. We need a parts diagram!

 

[Trielectric]

Ford has come out with the parts diagrams with the transmission in it and it appears that they add more info daily. I knew there were problems with the diagrams when I found an oil hose attached to a water pump in the parts diagrams. In our transmission diagrams there are a number of discrepancies and poor choices of names. The ring gear for the differential carrier is called a planet gear. I'd bet it is used on a planetary gearset in another transmission. I found the transfer gear set shown with the axis the same as the differential but nothing going into the bearing hole were it really is located. I compiled my ideas from the parts manuals and the cutaway pics. As always this is my best guess at the time.

1.The Motor shaft is hollow and the passenger side axle extender passes through it. The drivers side axle goes right into the differential.
2.On the drivers side of the motor a small hollow black gear is splined to the motor shaft. When the motor is turning, this gear is turning(35 to 50 teeth?).
3.The motor gear is engaged at all times with the large gear of the transfer gear(85 to 95 teeth?). The transfer gear is one piece with two gears on it.
4.The Notched parking gear is attached to the back of the large transfer gear.
5. The transfer gear small gear(20-25teeth) drives the differential carrier gear(70-80 teeth).
6. The differential carrier ring gear is bolted to the carrier housing using 12?bolts.
7. The carrier housing has the 4 spider gears inside of it that turn the axles that fit into 2 of the spider gears.
8. All the aforementioned gears turn whenever the motor is turning(the exception being the 4 differential spider gears, they are usually stationary inside the rotating carrier).
9. The gear shift shaft at the top of the transmission does two things. 1. It changes the electrical switch in the little black box out side and on top of the transmission. 2. It engages the parking pawl into the parking gear inside the transmission when you shift to Park.
10.There is a spring loaded piston moving against the gearshift shaft that the parts name suggests is a fluid valve. I am confident it is only a detent to keep the shifter shaft in Park.
11.The Motor turns the same direction as the front wheels. If we lighten the front of the car enough it should pull a wheelie(Not).

I could find no other sliding or nonrotating moving parts inside the transmission.
The transmission is splash lubricated. The drain and fill/check plugs are on the drivers end of the transmission.
Our "L" gear shift position must be electrical in the motor. The only reason for it to be there appears to be an ancient Federal law that you must have a way to slow down using the engine/motor turning resistance. This came about when brake failures were common place and automatics started to become popular.