Maint rumors? Color laments and tax questions.

[awilson]

The specs listed by the Ford Dealers all say the Ford Fusion Hybrid's transmission is the Aisin PowerSplit eCVT automatic transmission. The name should be pretty descriptive of what kind of transmission that is. :)

 

The Power Split Device in the Ford Escape Hybrid and Fusion Hybrid are both manufactured by Aisin Seiki in Japan. I don't have the particular Aisin model number for the Fusion Hybrid's Power Split Device yet, but the ones used in the Escape Hybrid are the Aisin T-030 and T-031. Aisin does have a Power Split Device transmission listed in their current catalog with an "HD-10" model number, with a 65kw (which is 86hp) MG2 electric motor. Sounds awfully like the specs for the FFH MG2.

 

Check out the attachment. That is the Ford Power Split Device.

 

 

And check out the Prius Power Split Device: http://www.eahart.com/prius/psd

 

They are the same kind of animal. B)

 

Hello Quincy,

Looking at the Aisin PSD and the excellent simulation of the Prius PSD on the eahart.com I spotted a difference in methodology. According to these documents the Ford and Toyota PSD's have the following arrangements:

 

FFH

- Traction Motor (MG1): Ring Gear

- Gasoline Engine (ICE): Planetary Gear

- Generator Motor (MG2): Sun Gear

 

Prius

- Traction Motor (MG1): Sun Gear

- Gasoline Engine (ICE): Planetary Gear

- Generator Motor (MG2): Ring Gear

 

Both arrangements would work. Do you know if indeed there is this difference between the FFH (Aisin) and Prius PSD's? Could this contribute to the smoother transition on the FFH when the ICE kicks in?

[lrymal]

Yup, that's where it is all right.... I passed right over that page, wading through all the other debris.

[WPWoodJr]

Hello Quincy,

Looking at the Aisin PSD and the excellent simulation of the Prius PSD on the eahart.com I spotted a difference in methodology. According to these documents the Ford and Toyota PSD's have the following arrangements:

 

FFH

- Traction Motor (MG1): Ring Gear

- Gasoline Engine (ICE): Planetary Gear

- Generator Motor (MG2): Sun Gear

 

Prius

- Traction Motor (MG1): Sun Gear

- Gasoline Engine (ICE): Planetary Gear

- Generator Motor (MG2): Ring Gear

 

Both arrangements would work. Do you know if indeed there is this difference between the FFH (Aisin) and Prius PSD's? Could this contribute to the smoother transition on the FFH when the ICE kicks in?

On the Prius MG2 is the traction motor (not the generator motor) and is connected to ring gear.

[Oman]

I think the systems are the same on both from a gearing point of view. If you work out the numbers it is the only way that makes sense. The traction motor has to be on the ring, which is directly connected to the drive wheels (through a reduction gear set). The ratio (variable gearing) control motor happens to work as a generator when it is providing a high input to output ratio, which makes the sun the best place for it. Both systems are built by the same company, of which Toyota is one of the owners. Toyota made some improvements to the magnet design and increased the RPM range in their G3 system. Ford made some changes to the motor size, controller, and gear ratios for the FFH. Ford made some design improvements to the ICE, I think they are ahead of Toyota there but hard data is tough to get because of the secretive nature of the technology and patents.

 

Both cars throw a bunch of energy out. I did some calculations on the maximum charge/discharge rates for the battery systems vs. maximum MG1 and MG2 power handling and it appears to me that the drive systems far outpower the battery systems. To go bigger on the battery would add considerable weight, which is a bigger hit than not wasting the extra power. As well in order to maintain a nearly indefinite battery life the systems only use a portion (roughly 50%) of the total available battery power. To fully charge and discharge the battery would greatly reduce its usable life.

 

I think we could get considerably better mileage (at least non-hwy) if the battery technology would improve, while still using the same mechanical systems. I use large Lithium Polymer battery packs for flying. They get about a dozen times better power to weight ratio than the technology used in the FFH or Prius, but man are they finicky and expensive. I for one would not be willing to replace a battery pack every year in my car for $5,000 just to get an extra 10 MPG. We need 2x the power, 1/2 the weight, and the ability to fully charge and discharge a pack indefinitely. Not using a highly volatile and explosive chemical (have you seen Lithium burn?) would be nice too :>

 

 

 

Jon

 

 

 

 

On the Prius MG2 is the traction motor (not the generator motor) and is connected to ring gear.