Neutral Coasting
#71
08-08-2007, 03:00 PM
Re: Neutral Coasting
If the vehicle were towed backwards the MG1 would just spin and unless it was loaded (MG1)nothing would happen.
#72
08-08-2007, 03:29 PM
Re: Neutral Coasting
GaryG — Which US patent (or other source) are you quoting from in post #55? You don't seem to say. By the way, in the Ford FEH/MMH "2005 MY OBD System Operation Summary for Hybrid Electric Vehicles" manual that you referred to on cleanmpg.com (I tried attaching it hereto, but the GH site refuses to accept it for some reason — GaryG can you please repost it here to help me out?), I note that the powertrain control system diagram on page 9 essentially repeats Fig. 1 from both US patents #6 793 034 and 6 405 818 (I'm attaching the latter hereto), and explicitly shows that the FEH/MMH system contains:
(a) a "one-way clutch" between the ICE and the planetary gear,
(b) a "generator brake" between the generator and the planetary gear, and
(c) a statement on the block diagram that the PCM can issue a "generator brake command."
[Other interesting information is also given on pages, 5-8, and 64.]
Now, the one-way ICE clutch would presumably be a passively-operating mechanical clutch, and inaudible. It would allow the transaxle planetary carrier shaft speed to exceed that of the ICE without spinning up the ICE. Is that what's happening during downhill coasting or power-off towing? I must mention that, in patent #6 405 818 referred to above (see col. 3, lines 7-14; col. 7, lines 60-67; col. 8, lines 17-26) it is stated that, in this arrangement, the generator clutch can be engaged when starting the ICE, and also at other times. This adds credence to some of your statements in earlier posts. [This patent also discusses, inter alia, engine braking = fuel-cut spinning of the ICE (col. 5, lines 36-51), quasi-"heretical"-mode operation (col. 6, lines 57-67), battery charging in 'N' (col. 7, line 18), and using MG1 as a motor to slow and stop the ICE (col. 7, lines 29-36).]
Stan
(a) a "one-way clutch" between the ICE and the planetary gear,
(b) a "generator brake" between the generator and the planetary gear, and
(c) a statement on the block diagram that the PCM can issue a "generator brake command."
[Other interesting information is also given on pages, 5-8, and 64.]
Now, the one-way ICE clutch would presumably be a passively-operating mechanical clutch, and inaudible. It would allow the transaxle planetary carrier shaft speed to exceed that of the ICE without spinning up the ICE. Is that what's happening during downhill coasting or power-off towing? I must mention that, in patent #6 405 818 referred to above (see col. 3, lines 7-14; col. 7, lines 60-67; col. 8, lines 17-26) it is stated that, in this arrangement, the generator clutch can be engaged when starting the ICE, and also at other times. This adds credence to some of your statements in earlier posts. [This patent also discusses, inter alia, engine braking = fuel-cut spinning of the ICE (col. 5, lines 36-51), quasi-"heretical"-mode operation (col. 6, lines 57-67), battery charging in 'N' (col. 7, line 18), and using MG1 as a motor to slow and stop the ICE (col. 7, lines 29-36).]
Stan
Wow! you read some of this stuff and want more?
Ming L. Kuang was the Ford Escape Hybrid Engineer who developed the Limited Operation Strategy (LOS) and at least 17 other Ford Escape hybrid patents. Kuang and other FEH engineers and patents are talked about here:
http://www.sae-detroit.org/e_images/saesc_38_125.pdf
The document you wanted me to repost here is:
http://www.motorcraftservice.com/vdi...DSM500_HEV.pdf
The language I quoted in post #55 came from this patent:
http://www.freepatentsonline.com/715...07&stemming=on
As far as the One-Way Clutch, this might help you a little:
http://www.freepatentsonline.com/20020066607.html
I read many of Ford patents that state the OWC can engage or disengage the ICE. I read the ICE is disengaged in EV when MG1 is providing torque to the wheels with MG2.
The drivetrain diagrams do match in patent 6405818 with the Systems Operating manual, and many other Ford patents I quoted. The patents on the disconnects and OWC are very general, and the diagrams are not limited to the FEH. However, the language in the disconnect patent describe the gear sets in the FEH. The OWC is an earlier patent, but other patents describe the OWC operation that have the same FEH drivetrain drawings. If you read carefully, the disconnect patent is referring
to the patent and the drivetrain drawings in patent 6793034 which matches patent 6405818 and the FEH System Operation Manual.
It's not easy to understand what your looking at in the drawings of these patents, and I think Ford was smart in hiding the OWC and the disconnects. An example also was a FEH patent I found that had the ICE and OWC connected directly to the generator brake and the generator before the planetary gear set. I couldn't believe my eyes and when back to the description of the drawings and they were the same as all the FEH description drawings. After the patent was published, someone found the mistake and changed the drawings to correct the mistake. Now there are two patents with the same title, but with correct drawings and one without.
GaryG
#73
08-08-2007, 03:33 PM
Re: Neutral Coasting
Found it. The OWC is on the engine to planitary shaft, its purpose apears to prevent the engine from turning back wards during reverse! I found NO disconect drawn or discribed.
Last edited by Mark E Smith; 08-09-2007 at 08:54 AM.
#74
08-09-2007, 09:06 AM
Re: Neutral Coasting
Actually the disconnect looks more like the Honda system than the FEH. A OWC is also known as a roller clutch or a sprag clutch depending on the design. these have been used in auto transmissions since the 50s. The FEH uses a SIMPLE planetary gear. If it did not have the OWC on the engine shaft there would be a possibility for the ICE to rotate backwards.
#75
08-10-2007, 02:44 PM
Re: Neutral Coasting
The tach bounce before you go EV maybe the output shaft disconnecting from the drive wheels confirming zero torque to the VSC. Tapping the brakes could be causing the ABS system to cause the VSC to disengage the wheels to prevent damage to eCVT and engine caused by inertia and powertrain reaction torque. Is all this related to why the double tap we earlier owners discovered a few years back to go EV? I'm beginning to think it does after finding that disconnect patent.
GaryG
GaryG
#76
08-11-2007, 10:23 AM
Re: Neutral Coasting
GaryG — Thanks for posting that file! I'll look at the other items you posted as soon as I have some time. Yes, I am interested in resolving this disagreement about the FEH's drive train. In the meantime, I must note that the one-way clutch, as shown in the "FEH OBD System Operation Summary" document (and in US patent #6 405 818) does not disconnect the ICE from the transaxle. All it does is prevent the ICE from rotating backwards. Since that patent was primarily concerned with maintaining limited vehicle operation in the event of failure in various system components, it's likely that it may be there to protect the ICE from damage during reverse towing or if MG1 fails.
Stan
Stan
#77
08-12-2007, 04:06 AM
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Join Date: Mar 2005
Location: All over the Central U.S.
Posts: 3,616
Re: Neutral Coasting
Coasting data, Neutral, Key on ( at normal run position )
From ScanGauge:
39 MPH ICE = 0 RPM
39 MPH TM = 5000 RPM
39 MPH GM = -6080 RPM
60 MPH ICE = 1400 RPM
60 MPH TM = 7680 RPM
60 MPH GM = -4610 RPM
82 MPH ICE = 2700 RPM
82 MPH TM = 10,500 RPM
82 MPH GM = -3630 RPM
( yes I have 75 MPH interstates, and the "flow" is 82 MPH in left lane )
Make of it what you will.
Everything always moves in concert.
Coasting in N no power (well, 0.6A) is going in or out of the HV battery.
Coasting in N significant fuel is being burned, same or more than in Drive.
I think I see more fuel being burned in N than in drive, because when in Drive, electrical power can be used to modify engine speed, reducing fuel consumption. In neutral, electrical power (IE generator) cannot be used to modify engine speed, and the converse is probably true, fuel is being used to control engine speed, which is turn is being used to control motor speed.
Knowing the above, tell me what & where things are physically disconnected when you move the shifter to N when in motion.
Thanks.
-John
From ScanGauge:
39 MPH ICE = 0 RPM
39 MPH TM = 5000 RPM
39 MPH GM = -6080 RPM
60 MPH ICE = 1400 RPM
60 MPH TM = 7680 RPM
60 MPH GM = -4610 RPM
82 MPH ICE = 2700 RPM
82 MPH TM = 10,500 RPM
82 MPH GM = -3630 RPM
( yes I have 75 MPH interstates, and the "flow" is 82 MPH in left lane )
Make of it what you will.
Everything always moves in concert.
Coasting in N no power (well, 0.6A) is going in or out of the HV battery.
Coasting in N significant fuel is being burned, same or more than in Drive.
I think I see more fuel being burned in N than in drive, because when in Drive, electrical power can be used to modify engine speed, reducing fuel consumption. In neutral, electrical power (IE generator) cannot be used to modify engine speed, and the converse is probably true, fuel is being used to control engine speed, which is turn is being used to control motor speed.
Knowing the above, tell me what & where things are physically disconnected when you move the shifter to N when in motion.
Thanks.
-John
#78
08-12-2007, 05:40 PM
Hybrid and Ethanol Expert
Join Date: Mar 2005
Location: All over the Central U.S.
Posts: 3,616
Re: Neutral Coasting
Someone ( Hobbit) suggested that I jack one wheel off the ground, place the car into "Neutral" and see how it "felt" moving it with your hand. Brilliant idea!
Not only could I feel TONS of mechanical resistance in "Neutral" but with the engine off, I could also hear lots of mechanical noise as moving parts were meshing together. Key was on, engine was off.
I found something even MORE interesting!
With one wheel jacked off the ground, and ICE running, in "Neutral" the wheel will spin on its own in the forward direction. Not much, but there is a tiny amount of forward torque on the wheels in Neutral. There was also a ton of resistance to me spinning the wheel backwards in Neutral, when the ICE was running, but could move it forward with one finger. Once I got the tire moving forward, it would continue to move forward on its own. The tires receive a tiny amount of positive torque in "Neutral".
I have video ( .mov ) of the tire spinning forward, on its own, with the car in Neutral. Can I upload a 10MB movie file to this site?
MORE POSITIVE PROOF THERE IS NO MECHANICAL DISCONNECT IN "Neutral".
Not only could I feel TONS of mechanical resistance in "Neutral" but with the engine off, I could also hear lots of mechanical noise as moving parts were meshing together. Key was on, engine was off.
I found something even MORE interesting!
With one wheel jacked off the ground, and ICE running, in "Neutral" the wheel will spin on its own in the forward direction. Not much, but there is a tiny amount of forward torque on the wheels in Neutral. There was also a ton of resistance to me spinning the wheel backwards in Neutral, when the ICE was running, but could move it forward with one finger. Once I got the tire moving forward, it would continue to move forward on its own. The tires receive a tiny amount of positive torque in "Neutral".
I have video ( .mov ) of the tire spinning forward, on its own, with the car in Neutral. Can I upload a 10MB movie file to this site?
MORE POSITIVE PROOF THERE IS NO MECHANICAL DISCONNECT IN "Neutral".
#79
08-12-2007, 06:50 PM
Re: Neutral Coasting
Coasting data, Neutral, Key on ( at normal run position )
From ScanGauge:
39 MPH ICE = 0 RPM
39 MPH TM = 5000 RPM
39 MPH GM = -6080 RPM
60 MPH ICE = 1400 RPM
60 MPH TM = 7680 RPM
60 MPH GM = -4610 RPM
82 MPH ICE = 2700 RPM
82 MPH TM = 10,500 RPM
82 MPH GM = -3630 RPM
( yes I have 75 MPH interstates, and the "flow" is 82 MPH in left lane )
Make of it what you will.
Everything always moves in concert.
Coasting in N no power (well, 0.6A) is going in or out of the HV battery.
Coasting in N significant fuel is being burned, same or more than in Drive.
I think I see more fuel being burned in N than in drive, because when in Drive, electrical power can be used to modify engine speed, reducing fuel consumption. In neutral, electrical power (IE generator) cannot be used to modify engine speed, and the converse is probably true, fuel is being used to control engine speed, which is turn is being used to control motor speed.
Knowing the above, tell me what & where things are physically disconnected when you move the shifter to N when in motion.
Thanks.
-John
From ScanGauge:
39 MPH ICE = 0 RPM
39 MPH TM = 5000 RPM
39 MPH GM = -6080 RPM
60 MPH ICE = 1400 RPM
60 MPH TM = 7680 RPM
60 MPH GM = -4610 RPM
82 MPH ICE = 2700 RPM
82 MPH TM = 10,500 RPM
82 MPH GM = -3630 RPM
( yes I have 75 MPH interstates, and the "flow" is 82 MPH in left lane )
Make of it what you will.
Everything always moves in concert.
Coasting in N no power (well, 0.6A) is going in or out of the HV battery.
Coasting in N significant fuel is being burned, same or more than in Drive.
I think I see more fuel being burned in N than in drive, because when in Drive, electrical power can be used to modify engine speed, reducing fuel consumption. In neutral, electrical power (IE generator) cannot be used to modify engine speed, and the converse is probably true, fuel is being used to control engine speed, which is turn is being used to control motor speed.
Knowing the above, tell me what & where things are physically disconnected when you move the shifter to N when in motion.
Thanks.
-John
I can't explain what's going on better than the FEH manual and the Great American All Ford Patents. It's clear Americans are not stupid.
I do my part every drive, my last tank was 649 miles at 46mpg during a hot summer.
GaryG
#80
08-13-2007, 05:59 AM
Hybrid and Ethanol Expert
Join Date: Mar 2005
Location: All over the Central U.S.
Posts: 3,616
Re: Neutral Coasting
You proved at HybridFest that Neutral stops regen? Um... no, you didn't. Everyone on the planet has known that fact since the car came out in 2004!
I will agree with you, that you can't explain things better than the FEH manual. At least we can agree on something.
Oh yeah... I can get 46 MPG on those days/weeks that I have "Florida like" weather and driving conditions. Most of the time it is worse though, so I'm not 'quite' there. 9 months of the year, my A.M. commute is below 50 degrees, 6 months of the year my A.M. commute is below 40 degrees, and 3 months a year my A.M. commute is below 30 degrees. 1 month a year I start out with a battery pack that is below 20 degrees.
Although this week, I must have BETTER weather than you.
The past 98 miles of this tank are sitting at 54.6 MPG right now.
Cheers!
I will agree with you, that you can't explain things better than the FEH manual. At least we can agree on something.
Oh yeah... I can get 46 MPG on those days/weeks that I have "Florida like" weather and driving conditions. Most of the time it is worse though, so I'm not 'quite' there. 9 months of the year, my A.M. commute is below 50 degrees, 6 months of the year my A.M. commute is below 40 degrees, and 3 months a year my A.M. commute is below 30 degrees. 1 month a year I start out with a battery pack that is below 20 degrees.
Although this week, I must have BETTER weather than you.
The past 98 miles of this tank are sitting at 54.6 MPG right now.
Cheers!
