Sulu

I know the difference between series and parallel hybrids. What you described as a series hybrid is a mild hybrid, not a series hybrid.

In a series hybrid, the internal combustion engine NEVER mechanically drives the wheels; the mechanical power is converted to electrical power, which in turn drives the electric motor that drives the wheels. A diesel-electric locomotive is a classic example of a series hybrid.

A series hybrid can also be described as having an electrical transmission rather than a mechanical transmission.

In a parallel hybrid, either the internal combustion engine or the electric motor individually, or both together, can drive the wheels. The 1-motor hybrid systems produced by most of the auto-manufacturers (Audi, MB, Hyundai, etc.) are parallel hybrids. At slow speeds, only the single electric motor drives the wheels (the engine is off); at higher speeds, only the internal combustion engine drives the wheels (through the normal automatic transmission), with the electric motor off or the engine turning the motor as a generator to recharge the battery; and when extra power is required, both the engine and the electric motor together drive the wheels.

GM's and Honda's old mild hybrids are similar to the 1-motor parallel hybrids except that the electric motor is not powerful enough to drive the car alone. The petrol engine alone can drive the wheels or it can be assisted by the electric motor, but the motor never drives by itself.

Finally, Ford's 1st-generation hybrid system was NOT licensed from Toyota. Ford developed it on their own and when they realised that it was similar to Toyota's hybrid system, they decided to seek a licence from Toyota, to avoid patent-infringement issues, but what they sold was their own design.

spwolf

while thats Ford'd line, I very much doubt that - since most of the components there were actually purchased from Toyota owned suppliers. In 2nd generation, they designed their own.

mmarshall

I don't think you and I really disagree on most of this. You just described it it in somewhat different terms than I did. And, of course, there are several new hybrid systems now that don't really fall totally into either of the older categories.

Perhaps so.....but I remember Ford reps distinctly saying they built the 1Gen Escape's Hybrid system under a Toyota license. They did not explain all the details of the license.

DreamGS4

What in the actual f***.... 11 speeds? God forbid if that tranny ever needs replacing...

I thought i read somewhere that with the current technology, CVTs are only able to support low torque applications, up to around 200-250 ft/lb tq. Correct me if im wrong

Honestly with a truck like that all it needs is a good ol' fashion 5 spd manual

mmarshall

Actually, some CVTs are used with V6s in the 250-300 ft-lbs. range, but, in general, you're right.....they are torque-limited.

Sulu

I speculate that the maximum torque that a belt-and-pulley CVT can handle is about 270 lb.ft / 370 Nm (give or take). This is based on the peak torque range of the Nissan VQ35 engine, the largest and most powerful engine that Nissan seems to use their CVTs with.

The belt-and-pulley CVT uses a metal belt made up of many metal links (to make it bendable) running between 2 pulleys: one pulley is turned by the engine crankshaft and the other pulley turns the driveshaft (transaxle). The gear ratio changes by changing the diameter of the 2 pulleys: one gets larger as the other gets smaller (and vice versa), all while maintaining tension on the belt as tight as possible to prevent slippage. Since the 2 pulleys do not have gear teeth, too much torque from the crankshaft will cause the belt to slip.

The metal belt is already an improvement on an older design that used rubber belts.

Audi has given up using CVTs, preferring dual-clutch automated manual transmissions.

Sulu

I have been interested in hybrid cars since the early 2000s, when Honda first introduced their first Insight hybrid in North America, and Toyota finally imported the Prius here after 3 years of sales in Japan.

So I distinctly remember the rumours back in 2004 when Ford first introduced their new hybrid system (in the Ford Escape Hybrid) that Ford had copied Toyota's technology. Ford strongly stated that was not the case, that they developed it on their own, but worried that it looked too similar to Toyota's system, decided to enter into a pre-emptive patent-sharing agreement (not merely a one-sided licensing by Ford of Toyota's hybrid system).

Of course Ford's first Power-Split Device eCVT was sourced from Aisin (an autoparts supplier belonging to the Toyota Group that co-developed the Prius' eCVT with Toyota); no other transmission manufacturer at the time had the know-how to design and build an eCVT. And Ford's first hybrid battery was sourced from Sanyo, which provided hybrid batteries to Honda (Panasonic provided the hybrid battery for the Prius).

Source: Wikipedia

spwolf

uh, what exactly did they develop if they purchased part from Toyota owned suppliers?

I understand that Ford PR does not want us to think they purchased parts, but that does not matter. If you outsourced all of the components, then what exactly did you develop?

I mean they outright purchased most of the things from Aisin:
http://www.greencarcongress.com/2007...seiki_to_.html

I am sure they did some system integration, it is no different than when they all purchase transmissions from Aisin or BW or ZF and then claim to "co-develop" them, and in the end, every car has even the same transmission stick (ZF).

For current systems, they designed them and built them in house... so if they are using Aisin motors and whoever's batteries, thats much less than buying everything from Aisin before.

Blackraven

Yup.
At the moment, the ones leading the charge for conventional CVT are Nissan (Maxima 350-370 Nm) and Subaru (from FA, EJ and EZ engines all the way to EE20 BOXER DIESEL ENGINE with 350 Nm mated to their Lineartronic CVT)

Conversely....
Yeah it's unfortunate but I guess it can't be helped. AUDI could not get their Multitronic CVT to work with their Quattro AWD drivetrain........and this creates a problem because quattro awd is a trait that defines the Audi brand.

Slightly related, MB used to have Autotronic CVT in the previous-gen A Class....

spwolf

As usual, simply because of its size, Toyota is largest CVT manufacturer in the world:
http://www.schaeffler.com/remotemedi...2010_09_en.pdf

Thats very nice report too... Toyota plans to use CVTs from 1.0l to 2.0l engines so far, and keeps AT's for more luxurious/faster vehicles.

New Auris 1.2t CVT should be finally really nice, with curve sensing it will behave more natural and not "shift" to 1200rpm mode while you are slowing down in curves.