For the vast majority of pure electric vehicles, the demand for multi-stage gearboxes is indeed low. Internal combustion engines require multi-stage transmissions to adjust torque and efficiency, so traditional fuel vehicles cannot get rid of the gearbox. However, in the case of pure electric vehicles, the electric motor does not need to be adjusted by a multi-stage transmission due to its high torque characteristics.
On the other hand, the peak efficiency of the motor is extremely high, and the range of high efficiency is very wide, so the role that the multi-stage transmission can play in terms of adjusting the efficiency is relatively weak. Therefore, many friends are puzzled about how traditional transmission companies such as ZF, Aisin and GETRAG should survive in the new energy eraOn the surface, these transmission giants are indeed facing an existential crisis, but in fact, these companies are transforming.
Torque in the internal combustion engine is not a strong point and is heavily dependent on engine speed, and the torque output is too weak at low rpm. Such as a 1The 5-liter self-aspirated engine has a peak torque of about 150Nm, and it can output 30Nm at 600-700 rpm at the start. Can this torque drive a car of more than 1 ton to complete the start smoothly?Obviously, it can't, so the gearbox of a fuel vehicle should be equipped with at least two low-speed gears, and the 1st gear ratio is 45 or more. Combined with the tail tooth ratio, the gearbox can amplify the engine torque by more than 16 times in first gear.
30nm*16=480Nm, such a torque output is enough to complete the start. But the motor is different, the motor can output peak torque at very low speed or even 0 rpm, such as 500Nm at the start, and with a fixed transmission ratio to amplify the torque, it can output more than 1000Nm at the start. So the motor doesn't need a low-speed gear to increase torque. On the other hand, the efficiency of the motor is not easily affected by load and speed, for example, the efficiency is 95% at 6000 rpm and medium load, and 93% at 9000 rpm and full load.
The difference is only 2% (2% at high levels), which is not the case with an internal combustion engine, which can achieve a thermal efficiency of 40% at 2500 rpm at medium load. However, at 6000 rpm and full load, the thermal efficiency may be less than 20%, and this huge efficiency difference leads to the internal combustion engine must use the gearbox to adjust the speed and torque to play a role in adjusting the efficiency. And no matter how tossed the motor, the efficiency is always at a high level. Even if it is equipped with a multi-stage gearbox, it can only play the role of pressure speed, which can reduce the friction work loss, but this part of the loss is very low. Therefore, there is a positive benefit to equipping the tram with a gearbox, but the benefit is not proportional to the input.
There is always a saying on the Internet that "ZF defeated all its opponents, but lost to the times"?But will ZF really lose to the times?Actually, no, if we ordinary people can understand the problems and see the hidden dangers, can't the ZF management see it?ZF is indeed a hegemon in the field of longitudinal transmissions, but ZF does not just sell transmissions for fuel vehicles. ZF also manufactures electric and hybrid vehicles, and even ZF is the technology enabler behind the process of vehicle electrification. So the car is transforming, and these traditional transmission giants are also transforming.
In order to achieve energy balance, the proportion of pure electric vehicles in the future may be very high, but it is unrealistic to completely eliminate fuel vehicles, for the simple reason that there is not enough electricity. ZF's market forecast for 2030 is that 15%-20% of the market will be pure electric vehicles, about 40% will be hybrid vehicles, and the remaining 40% will be pure gasoline vehicles. Therefore, until 2030, the basic plate of oil vehicles is still there, and ZF can provide transmissions for oil vehicles, and also has the ability to provide transmissions for hybrid units. Of course, Aisin also has this ability.
As shown in the picture above, ZF's fourth-generation 8AT 8H60 is a gearbox designed to match hybrid units. In the future, pure fuel vehicles are likely to be discontinued, or even restricted, but the life of hybrid models will still be very long. The plans announced by various automakers to stop production of gasoline vehicles refer to pure fuel vehicles, not hybrid models. The picture below shows ZF's two-speed automatic transmission for electric vehicles, which is currently fitted to some of Porsche's electric models. Although it is difficult to popularize multi-stage gearboxes for passenger pure electric models in the future, multi-stage gearboxes are still very necessary for some models with tool attributes.
The reason why many friends think that after pure electric vehicles become a major trend, traditional transmission companies will collapse, is that they think that these transmission bosses will only make gearboxesIn fact, as a large enterprise in the automotive field, ZF can build far more than gearboxes, and the field it is involved in is not only limited to fuel vehicles. In the field of pure electric vehicles, ZF is also involved in motors, electronic controls, reducers, software control and so on. The figure below shows the integrated differential products offered by ZF.
The two rows of planetary gear sets have achieved deceleration and differential speed at the same time, reducing the weight by about 10%, reducing the volume by 15%, and reducing the transmission loss by about 25% compared with the traditional fixed-shaft reducer, and is currently in mass production. In terms of drive motors, ZF has already produced 2 million units in series. As early as the beginning of this year, ZF's 800V silicon carbide electric drive system has also officially rolled off the production line at the Hangzhou plant, and the orders in hand have exceeded 23 billion euros. This is almost more than the sales for the first half of 2022.
Even in 2023, ZF's sales growth will still reach more than 10% year-on-year, and traditional transmission giants such as ZF and Aisin are still strong. It cannot be said that there is no pressure or challenge, but it can only be said that the transformation is not only reflected in those traditional fuel vehicle bosses, but these old fuel vehicle manufacturers are also quietly transforming, but many friends do not understand. It's like Bosch is the leading manufacturer of fuel vehicles, but in the era of pure electric vehicles, Bosch is still the main manufacturer.
For any large enterprise in the world, its product line is by no means single, but diversified and matrixed. ZF's electric drive system and electric drive module actually started to be the first market in 2019, and the market share is still quite large. Of course, the transition will inevitably bring pains, but ZF doesn't just sell gearboxes. Even if only the gearbox is sold, there will be many pure electric models that will be equipped with the gearbox in the future. This is the same as the fuel car, the earliest fuel car did not have a gearbox, and later there was a single-stage differential device, and then the multi-stage gearbox was gradually popularized.
The same is true for trams, which are only the enlightenment of the new energy era today, while the pure electric models of the future will be more mature and reasonable. When automatic transmissions designed specifically for electric cars increase in production and reduce costs, it is not impossible for electric vehicles to be equipped with a multi-speed transmission as standard. After all, it is not cost-effective to exchange tens of thousands of yuan for a 5% increase in battery life, and what if a gearbox costs hundreds or thousands of yuan?It is very cost-effective to exchange an investment of hundreds or thousands of yuan for a 5% increase in battery life. Therefore, no matter who owns the trams and oil vehicles in the future, it is difficult to change the status of traditional first-class businessmen such as ZF, Aisin and Getrag. Even if the cars are gone, these ** merchants still exist, but they have changed the types of ** goods.