Neutral Coasting
#101
08-23-2007, 08:38 PM
Re: Neutral Coasting
This article gets better as you view it. Great information! Take a look at the battery pack!
Example
Electric Drive
The engine is off; the vehicle is propelled by stored electrical energy only; the torque can be
supplied from the traction motor, or a combination of both motors
• Hybrid Drive
The engine is on; the traction motor can operate as a motor or a generator to make up the
difference between the engine power and the desired power
– Split: The generator motor controls the engine speed (creating or using electricity)
– Parallel: The generator brake is engaged (similar to overdrive)
• Braking
– Vehicle braking can be done with the engine on or off and is delivered by the brakes, the
traction motor or a combination of both
• Neutral Functionality
– The engine is always connected to the wheels through the planetary gear set; neutral
functionality provides zero propulsion torque to the wheels
• Reverse
– Reverse torque is provided by the traction motor
• “Low” Functionality (B gear)
– There is no physical low gear; increased regenerative braking and engine braking are blended
to efficiently provide retard functionality
http://www.nextenergy.org/cm/attach/...ns%20Panel.pdf
Enjoy
GaryG
Example
Electric Drive
The engine is off; the vehicle is propelled by stored electrical energy only; the torque can be
supplied from the traction motor, or a combination of both motors
• Hybrid Drive
The engine is on; the traction motor can operate as a motor or a generator to make up the
difference between the engine power and the desired power
– Split: The generator motor controls the engine speed (creating or using electricity)
– Parallel: The generator brake is engaged (similar to overdrive)
• Braking
– Vehicle braking can be done with the engine on or off and is delivered by the brakes, the
traction motor or a combination of both
• Neutral Functionality
– The engine is always connected to the wheels through the planetary gear set; neutral
functionality provides zero propulsion torque to the wheels
• Reverse
– Reverse torque is provided by the traction motor
• “Low” Functionality (B gear)
– There is no physical low gear; increased regenerative braking and engine braking are blended
to efficiently provide retard functionality
http://www.nextenergy.org/cm/attach/...ns%20Panel.pdf
Enjoy
GaryG
#102
08-24-2007, 12:03 AM
Hybrid and Ethanol Expert
Join Date: Mar 2005
Location: All over the Central U.S.
Posts: 3,616
Re: Neutral Coasting
Congratulations! On both!
So.... now we have TWO people saying the wheels are always connected.
Me, and Phil Rairigh, Metrologist, Sustainable Mobility Technologies, Advanced Battery Systems at
Ford Motor Company!
Also of worthwhile note is the mention of a battery heater...
First mentioned two years ago by....?
Yes. A very good find. You're a good man for passing it along.
-John
So.... now we have TWO people saying the wheels are always connected.
Me, and Phil Rairigh, Metrologist, Sustainable Mobility Technologies, Advanced Battery Systems at
Ford Motor Company!
Also of worthwhile note is the mention of a battery heater...
First mentioned two years ago by....?
Yes. A very good find. You're a good man for passing it along.
-JohnLast edited by gpsman1; 08-24-2007 at 01:04 AM.
#103
08-24-2007, 07:26 AM
Re: Neutral Coasting
I 'think' the motor and generator spin when the car is towed wheels down.
Sounds strange, but it could be true.
Sounds strange, but it could be true.
BTW I find no disconect and I believe the MG1 and MG2 are in a rotating no load state in neutral.
#104
08-24-2007, 07:59 AM
Re: Neutral Coasting
GaryG
#105
08-24-2007, 08:26 AM
Re: Neutral Coasting
I believe the OWC is soley there to prevent the ICE from turning backwards in certain conditions. A ICE that turns backwards can damage itself because the cam chain tensioners will loosen and the timing chain can jump bending valves breaking pistons etc.
#106
08-24-2007, 12:00 PM
Hybrid and Ethanol Expert
Join Date: Mar 2005
Location: All over the Central U.S.
Posts: 3,616
Re: Neutral Coasting
For clarity, the terms as commonly used on this site and others:
Engine = gasoline Internal Combustion Engine ( or ICE )
Motor = Traction motor - the larger electric motor, provides most propulsion
Generator = Generator motor - the smaller electric motor - provides most battery recharging, and is responsible for starting up the ICE ( and controlling ICE speed ).
Engine = gasoline Internal Combustion Engine ( or ICE )
Motor = Traction motor - the larger electric motor, provides most propulsion
Generator = Generator motor - the smaller electric motor - provides most battery recharging, and is responsible for starting up the ICE ( and controlling ICE speed ).
#107
08-25-2007, 06:00 PM
Re: Neutral Coasting
It occurs to me that the function of OWC is to limit the engine to being only a power/torque input to the planetary gear set, and with only one direction of rotation. Consequently, the OWC prevents power or torque from being transmitted from the planetary gear set back to the engine. Starting mode must be the direct connection between the generator and engine, with no power or torque from the ring gear and wheels during that process.
Any thoughts anyone?
GaryG
Last edited by GaryG; 08-25-2007 at 06:04 PM.
#108
08-26-2007, 12:53 AM
Hybrid and Ethanol Expert
Join Date: Mar 2005
Location: All over the Central U.S.
Posts: 3,616
Re: Neutral Coasting
I said a long time ago that parts of the std. Escape Owner's Manual was cut & pasted into the hybrid manual, in places that some non-engineer felt were the same. ( seat belts, air bags, etc. ) This may be the case here. Also let me remind you that an Owner's Manual is not a technical document, and is mostly designed to tell you how to operate the car, NOT how the car operates! There is a difference! If that line of text "disengaged from the wheels" made it into the service manual I'm sure it was overlooked, since that particular item is not related to "service".
I visualize the OWC as a ratchet for your socket set. When you turn the handle one way, you can put torque into the bolt. Turn the handle the other way, and you cannot transfer torque into the bolt. The bolt and the socket are "always connected" but "torque" only flows one-way.
The generator motor starts the car, because it is always connected to the engine.... even when towing. However, when towing, it is like you moving the ratchet handle in reverse, still connected to the bolt ( engine ) but no torque is transfered.
When you start the car in Park, the ring gear ( traction motor ) is held still by the parking pawl. Power & rotation moves between the generator and ICE. Starting, the generator spins the ICE. Charging the battery pack in park, the ICE spins the generator. All 3 parts are "connected" the whole time... just the third part, the traction motor ( ring gear ) never moves an inch.
When towing, the carrier (ICE) is still. Towing transfers rotation from the ring gear to the sun gear ( generator ). All three parts including the engine are "connected" but the carrier gear never moves. It is only rotation transferred between the two motors, no torque, since there is no electrical current.
You cannot start the engine in "neutral" standing still, because there is no parking pawl to hold the ring gear still. There is no "reaction torque" and so the generator torque will try to spin both the ring gear and the carrier gear at the same time. BAD IDEA! This would make the car move if you started the car in neutral without your foot firmly enough on the disc brakes!
You can start the car in "neutral" over 6 miles per hour since the momentum of the car moving the ring gear can provide torque to actually help start the car if the generator brake is applied. Also, since the car is already in motion, there is no "surprise" motion to the driver.
I can't prove it happens, but it is possible to "push start" the FEH.
Above 20 MPH the FEH, in theory, can start the car solely by mechanical momentum. If a generator brake is applied, then the moving wheels moving the ring gear, can transfer torque into the ICE... enough to get it to 1000 RPM and fire up. This would only work coasting forward. Applying a generator brake while moving in reverse would try to spin the ICE in reverse, which would put the OWC to the test!
So guess what? The wheels CAN apply torque to the ICE, and you can have a true engine brake, but only a modest amount. The generator brake method only would spin up the ICE about 1000 RPM over a fast idle... and with the low compression of this engine, that would give you some, but not much stopping power. Probably about the same as a "second" gear.
To really slow you down, you need the traction motor working as a generator to get negative torque, and the power generated can be fed into the generator, which can spin the ICE ~3000 RPM over fast idle. Now you will get both electromagnetic slowing, and engine compression braking at the same time, which feels very close to a "first" gear.
Gary, the OWC does not prevent torque from "going into" the engine.
Torque can, and does go into the engine every single day.
The OWC only prevents reverse direction rotation.
The sun gear and ring gear can both put torque into the engine in the forward direction.
-John
I visualize the OWC as a ratchet for your socket set. When you turn the handle one way, you can put torque into the bolt. Turn the handle the other way, and you cannot transfer torque into the bolt. The bolt and the socket are "always connected" but "torque" only flows one-way.
The generator motor starts the car, because it is always connected to the engine.... even when towing. However, when towing, it is like you moving the ratchet handle in reverse, still connected to the bolt ( engine ) but no torque is transfered.
When you start the car in Park, the ring gear ( traction motor ) is held still by the parking pawl. Power & rotation moves between the generator and ICE. Starting, the generator spins the ICE. Charging the battery pack in park, the ICE spins the generator. All 3 parts are "connected" the whole time... just the third part, the traction motor ( ring gear ) never moves an inch.
When towing, the carrier (ICE) is still. Towing transfers rotation from the ring gear to the sun gear ( generator ). All three parts including the engine are "connected" but the carrier gear never moves. It is only rotation transferred between the two motors, no torque, since there is no electrical current.
You cannot start the engine in "neutral" standing still, because there is no parking pawl to hold the ring gear still. There is no "reaction torque" and so the generator torque will try to spin both the ring gear and the carrier gear at the same time. BAD IDEA! This would make the car move if you started the car in neutral without your foot firmly enough on the disc brakes!
You can start the car in "neutral" over 6 miles per hour since the momentum of the car moving the ring gear can provide torque to actually help start the car if the generator brake is applied. Also, since the car is already in motion, there is no "surprise" motion to the driver.
I can't prove it happens, but it is possible to "push start" the FEH.
Above 20 MPH the FEH, in theory, can start the car solely by mechanical momentum. If a generator brake is applied, then the moving wheels moving the ring gear, can transfer torque into the ICE... enough to get it to 1000 RPM and fire up. This would only work coasting forward. Applying a generator brake while moving in reverse would try to spin the ICE in reverse, which would put the OWC to the test!
So guess what? The wheels CAN apply torque to the ICE, and you can have a true engine brake, but only a modest amount. The generator brake method only would spin up the ICE about 1000 RPM over a fast idle... and with the low compression of this engine, that would give you some, but not much stopping power. Probably about the same as a "second" gear.
To really slow you down, you need the traction motor working as a generator to get negative torque, and the power generated can be fed into the generator, which can spin the ICE ~3000 RPM over fast idle. Now you will get both electromagnetic slowing, and engine compression braking at the same time, which feels very close to a "first" gear.
Gary, the OWC does not prevent torque from "going into" the engine.
Torque can, and does go into the engine every single day.
The OWC only prevents reverse direction rotation.
The sun gear and ring gear can both put torque into the engine in the forward direction.
-John
Mark, the manual however states in Neutral, the output shaft is disengaged from the wheels.
It occurs to me that the function of OWC is to limit the engine to being only a power/torque input to the planetary gear set, and with only one direction of rotation. Consequently, the OWC prevents power or torque from being transmitted from the planetary gear set back to the engine. Starting mode must be the direct connection between the generator and engine, with no power or torque from the ring gear and wheels during that process.
Any thoughts anyone?
GaryG
It occurs to me that the function of OWC is to limit the engine to being only a power/torque input to the planetary gear set, and with only one direction of rotation. Consequently, the OWC prevents power or torque from being transmitted from the planetary gear set back to the engine. Starting mode must be the direct connection between the generator and engine, with no power or torque from the ring gear and wheels during that process.
Any thoughts anyone?
GaryG
#109
08-26-2007, 03:35 PM
Re: Neutral Coasting
I visualize the OWC as a ratchet for your socket set. When you turn the handle one way, you can put torque into the bolt. Turn the handle the other way, and you cannot transfer torque into the bolt. The bolt and the socket are "always connected" but "torque" only flows one-way.
The generator motor starts the car, because it is always connected to the engine.... even when towing. However, when towing, it is like you moving the ratchet handle in reverse, still connected to the bolt ( engine ) but no torque is transfered.
When you start the car in Park, the ring gear ( traction motor ) is held still by the parking pawl. Power & rotation moves between the generator and ICE. Starting, the generator spins the ICE. Charging the battery pack in park, the ICE spins the generator. All 3 parts are "connected" the whole time... just the third part, the traction motor ( ring gear ) never moves an inch.
When towing, the carrier (ICE) is still. Towing transfers rotation from the ring gear to the sun gear ( generator ). All three parts including the engine are "connected" but the carrier gear never moves. It is only rotation transferred between the two motors, no torque, since there is no electrical current.
You cannot start the engine in "neutral" standing still, because there is no parking pawl to hold the ring gear still. There is no "reaction torque" and so the generator torque will try to spin both the ring gear and the carrier gear at the same time. BAD IDEA! This would make the car move if you started the car in neutral without your foot firmly enough on the disc brakes!
You can start the car in "neutral" over 6 miles per hour since the momentum of the car moving the ring gear can provide torque to actually help start the car if the generator brake is applied. Also, since the car is already in motion, there is no "surprise" motion to the driver.
I can't prove it happens, but it is possible to "push start" the FEH.
Above 20 miles per hour the FEH, in theory, can start the car solely by mechanical momentum. If a generator brake is applied, then the moving wheels moving the ring gear, can transfer torque into the ICE... enough to get it to 1000 RPM and fire up. This would only work coasting forward. Applying a generator brake while moving in reverse would try to spin the ICE in reverse, which would put the OWC to the test!
So guess what? The wheels CAN apply torque to the ICE, and you can have a true engine brake, but only a modest amount. The generator brake method only would spin up the ICE about 1000 RPM over a fast idle... and with the low compression of this engine, that would give you some, but not much stopping power. Probably about the same as a "second" gear.
To really slow you down, you need the traction motor working as a generator to get negative torque, and the power generated can be fed into the generator, which can spin the ICE ~3000 RPM over fast idle. Now you will get both electromagnetic slowing, and engine compression braking at the same time, which feels very close to a "first" gear.
Gary, the OWC does not prevent torque from "going into" the engine.
Torque can, and does go into the engine every single day.
The OWC only prevents reverse direction rotation.
The sun gear and ring gear can both put torque into the engine in the forward direction.
-John
The generator motor starts the car, because it is always connected to the engine.... even when towing. However, when towing, it is like you moving the ratchet handle in reverse, still connected to the bolt ( engine ) but no torque is transfered.
When you start the car in Park, the ring gear ( traction motor ) is held still by the parking pawl. Power & rotation moves between the generator and ICE. Starting, the generator spins the ICE. Charging the battery pack in park, the ICE spins the generator. All 3 parts are "connected" the whole time... just the third part, the traction motor ( ring gear ) never moves an inch.
When towing, the carrier (ICE) is still. Towing transfers rotation from the ring gear to the sun gear ( generator ). All three parts including the engine are "connected" but the carrier gear never moves. It is only rotation transferred between the two motors, no torque, since there is no electrical current.
You cannot start the engine in "neutral" standing still, because there is no parking pawl to hold the ring gear still. There is no "reaction torque" and so the generator torque will try to spin both the ring gear and the carrier gear at the same time. BAD IDEA! This would make the car move if you started the car in neutral without your foot firmly enough on the disc brakes!
You can start the car in "neutral" over 6 miles per hour since the momentum of the car moving the ring gear can provide torque to actually help start the car if the generator brake is applied. Also, since the car is already in motion, there is no "surprise" motion to the driver.
I can't prove it happens, but it is possible to "push start" the FEH.
Above 20 miles per hour the FEH, in theory, can start the car solely by mechanical momentum. If a generator brake is applied, then the moving wheels moving the ring gear, can transfer torque into the ICE... enough to get it to 1000 RPM and fire up. This would only work coasting forward. Applying a generator brake while moving in reverse would try to spin the ICE in reverse, which would put the OWC to the test!
So guess what? The wheels CAN apply torque to the ICE, and you can have a true engine brake, but only a modest amount. The generator brake method only would spin up the ICE about 1000 RPM over a fast idle... and with the low compression of this engine, that would give you some, but not much stopping power. Probably about the same as a "second" gear.
To really slow you down, you need the traction motor working as a generator to get negative torque, and the power generated can be fed into the generator, which can spin the ICE ~3000 RPM over fast idle. Now you will get both electromagnetic slowing, and engine compression braking at the same time, which feels very close to a "first" gear.
Gary, the OWC does not prevent torque from "going into" the engine.
Torque can, and does go into the engine every single day.
The OWC only prevents reverse direction rotation.
The sun gear and ring gear can both put torque into the engine in the forward direction.
-John
If you think about what you just stated about the OWC is like a ratchet, your right. You just don't understand how a ratchet works. If the engine is turning clockwise with the wheels, then any rotation by the wheels faster in the clockwise rotation than the engine would free ratchet, not increase the engine speed. Go out and get your ratchet and you will see what I mean. Lock the ratchet so you turn the bolt clockwise, and you will see you can hold the ratchet still and still turn the bolt clockwise without turning the ratchet. However, you can't turn the bolt counterclockwise because of the ratchet. This is the OWC that will not let the engine turn counterclockwise.
Now, during the starting mode, the OWC must lock-up in both directions to spin the engine with the generator in the clockwise direction to start the engine. The OWC allows shutdown of the engine while the wheels keep spinning because of this ratchet effect. This also allows the wheels to spin during neutral tow without turning the engine.
Push starting the FEH/MMH is totally impossible John. This even goes back to the manual also which says no forward or reverse gear can be engaged if the vehicle is not started.
If the OWC can locked-up in both directions like in the starting mode, then engine braking can be possible. A Ford engineer PM'ed me a few months ago and told me the generator run-up happens under 40mph, but after 40mph, it was a totally different strategy. For some reason, he would not return questions I ask him or her after that one PM.
One thing that I don't understand if there are no other disconnects, is how the generator can start the engine while traveling in reverse. I think it was in those documents I just posted that the generator can assist the wheels in forward, but not reverse.
GaryG
#110
08-26-2007, 04:07 PM
Re: Neutral Coasting
One thing that I don't understand if there are no other disconnects, is how the generator can start the engine while traveling in reverse. I think it was in those documents I just posted that the generator can assist the wheels in forward, but not reverse.
BTW I have already found a few mistakes in the shop manuals.
