http://www.designnews.com/article/CA....html?ref=nbra

This article has more details about the 2-mode transmission and a couple of videos. One shows the motors in operation and the other shows a moving cutaway of the internal parts. BTW, 60-KW is ~80hp. Included in the article was this system sketch:


Interesting although I wonder why the first clutch is needed. The planetary gear between the ICE and first motor makes sense but the clutch doesn't. Otherwise, the rest looks good to me.

Bob Wilson

 

It might be there to atenuate the torque spikes caused by the ICE. It may also suppress some of the vibrations before they reach a tight running planetary gearset. This could be a mandatory design feature/compromize for larger engine platforms - which this appears to be the case.


Cheers;

MSantos

 

The Prius has a permanent clutch called a "torque limiter" that is a clutch-plate bolted to the flywheel holding a clutch disk. The disk still has the rotational springs but otherwise, is a fixed part of the drive train. There have been reports of the torque limiter wearing out in Europe where higher speeds are more commonly found.

Bob Wilson

 

Did you see the description of the 2-mode presented by GM/BMW/DC earlier. From their schematics it appears that they see their main benefits as being that they have a larger flow of mechanical energy ( ICE+traditional transmission ) than the Toyota model which has a larger flow of electrical energy.

The fact that they can use an existing mechanical coupling which is durable enought for large vehicles and heavy towing with an electrical alternative at times of low load gives them a benefit in large SUV's and trucks. The THS being primarily, in their view, electrical power is not durable enough for heavy duty applications.

The three 2-moders further go on to point out that their system is 'scalable' to any vehicle since the motors are part of an existing mechanical transmission. This is where they say that migrating the system to the Aura or Malibu or even down to the Cobalt or G5 is easily done.

Much of what is already part of the current hybrid systems will also be part of the 2-mode package; regenerative braking, engine off during coasting and stopping. Although I don't think that they will be able to charge their battery packs during continuous operation such as a long highway drive ( no PSD ). I have to look further into this though.

It does look like an interesting development. My main question is while it is 'scalable' to smaller vehicles will the basically mechanical coupling ( ICE==>mechanical tranny ) be as efficient as the THS II ( or THS III )?

It may be that GM/DC/BMW have staked out the heavy vehicle segment.
Toyota has staked out the midsized vehicle segment.
Honda has staked out the small vehicle segment.

All of this is subject to sudden new technological developments now hidden in some corporate fortress lab.

 

A number of unexplained mechanical appendages often appear in new designs that are only there to avoid patent infringement.

For example, the Atkinson cycle, as superior as it is to the Otto cycle, was only invented as a way to get around the Otto patents.