Although the recent industry hot is the competition between plug-in hybrid vehicles and extended range "who is the big guy", for most people, I am afraid that gasoline-electric hybrid vehicles are the most secure and most suitable choice for the vast majority of people. We all know that most of the fuel hybrid vehicles can achieve a very low average fuel consumption, no matter how to drive, no matter how cold or hot, the fuel consumption is at most 5L, and the low can even run to 3L.
So, what does a fuel hybrid rely on to achieve such low fuel consumption? Most media will tell you that it depends on the perfect cooperation of the Atkinson cycle engine and motor. Yes, that's true, but if we ask: how do these two things work together? It is estimated that not many people can answer.
The e-CVT gearbox is what it does. But don't be fooled by its name, e-CVT, and the CVT gearbox we know, are not a thing at all.
The structure of the CVT gearbox is estimated to be known to everyone: two steel wheels, with a steel belt in the middle. The drum is movable, and the steel belt slides around in the groove of the drum to achieve an infinitely adjustable transmission ratio by infinitely changing the diameter of both ends of the drum, which is why CVT is called a continuously variable gearbox.
The advantages and disadvantages of CVT are also clear to everyone, the advantage is that the transmission efficiency is relatively high, very fuel-efficient, the disadvantage is that it cannot withstand large torque and will slip, so this is why CVT is generally only used in cars with relatively weak power output. Well, do you think e-CVT is related to CVT?
Looking at the name, you may think, could this thing replace some part of the CVT gearbox with a motor or electronic components? So it's called e-CVT? However, everyone is wrong, the only connection between e-CVT and CVT is the three letters CVT in the name, nothing more. Whether it is the structure or working principle, e-CVT and CVT can be said to be incompatible.
So you may have to ask, then this CVT that is not related to CVT (a bit of a mouthful), what is its structure? And how does it work? I'm sorry, but the e-CVT doesn't even have a fixed mechanical structure, or rather, this kind of thing is not very much of a "gearbox" in the traditional sense.
Confused by me? Let's just say that the e-CVT is actually a coupling system in a gasoline-electric hybrid system that connects the flywheel of the internal combustion engine and the half shaft. The "e" in the e-CVT stands for the drive motor, which is the drive motor that implements EV mode in the oil-mixed vehicle. The transmission part of the e-CVT system (note that we no longer call it a gearbox), that is, the traditional "gearbox" part, the structure of each manufacturer is different.
For example, Toyota and Honda's oil hybrid vehicles are equipped with e-CVT, both are front-wheel drive cars, and both are unequal length half shaft designs. However, the mechanical structure of the transmission part of the e-CVT is completely different between the two car companies. Toyota's e-CVT uses a planetary gear set to achieve power transmission, which is more similar in structure to a streamlined version of a traditional AT gearbox. On the other hand, Honda's e-CVT, the structure of the transmission part is a single multi-plate composite electromagnetic clutch. This electromagnetic clutch is responsible for controlling the on-off of the motor power, and also responsible for cutting off or connecting the power transmission between the oil engine and the half shaft. When in EV mode, the internal combustion engine is shut down and the car is driven solely by the electric motor. In hybrid mode, the motor and oil generator together output power to the half shaft, and in high-speed mode, the motor stops the oil engine drive.
The structure of Honda's e-CVT system has also been borrowed from some domestic brands of hybrid systems, which call this system "DHT hybrid". The oil hybrid vehicles of other car companies, as long as they do not use Honda's electromagnetic clutch, also have their own unique structure. All in all, e-CVT is not a type of gearbox, it has no fixed mechanical structure, as long as it can realize the joint work of the oil engine motor mechanical system, it can be called e-CVT.
In fact, most car companies do not call this system "e-CVT", but more "DHT hybrid". But the reason why this type of mechanical bridging system was originally put on this name is actually related to Toyota.
Everyone knows that the Toyota Prius is the most successful of the original oil hybrid in terms of product, sales and marketing (the first oil hybrid car is not it, it is the Honda insight). But at that time, Toyota's marketing department encountered a tricky problem: how to explain to the public that the set of oil engine motors on the Prius is combined with the function of the gearbox, and part of the structure is directly evolved from the AT gearbox?
That was in 2003, when CVT gearboxes were just getting up and known for their low fuel consumption, while AT transmissions of the same period were still perceived by the public as "more fuel-intensive and less efficient than manual transmissions". So in view of the Prius's strong emphasis on fuel-saving and intelligent two product forces, Toyota's marketing team immediately thought of CVT gearbox.
Thus, the name e-CVT appeared. In the public mind at the time, e-CVT seemed to be a "highly intelligent version" of CVT. Prius's "personality", with the help of the marketing word e-CVT, quickly gained a foothold around the world. So to put it bluntly, e-CVT was a marketing word at the beginning, not a technical word.
In fact, whether it is e-CVT or DHT hybrid, this is all marketing words. The coupling system of most oil hybrid vehicles is basically a variety of "magic modifications" of Honda's i-MMD system (Toyota's planetary gear transmission mode has been patented, and it cannot be used elsewhere). From the actual performance of these systems, they have indeed achieved quite high mechanical transmission efficiency and energy transfer efficiency. It can be said that these systems, especially Honda's i-MMD and countless derivatives, have basically reached the highest level of mechanical transmission capacity of oil hybrid vehicles.
This is why the fuel consumption level of oil hybrid vehicles has never been able to exaggerate. But compared to plug-in mixing, we believe that oil blending with higher theoretical fuel consumption figures is actually a more suitable choice for most people.