Posted 2021-01-20 00:00:00 +0000 UTC
ZF, as a well-known transmission system solution manufacturer in the world, is also a manufacturer. It has a very high voice in the field of transmission of commercial vehicles and passenger vehicles. Its main 8HP series 8at automatic transmission has been praised by manufacturers and consumers all over the world. For the 8HP series 8at gearbox introduced by ZF, it has always been highly praised in the passenger car market, and even called one of the best gearboxes in the current civil field. At the beginning, ZF developed 8HP series transmission on the basis of 6hp series transmission to improve transmission efficiency, fuel economy and vehicle motion properties. At last, zf8hp series 8at transmission was favored by high-end models of manufacturers with its balanced performance. After ZF created the 8HP series gearbox, although there is little change in the name of the series, ZF manufacturers continue to optimize and upgrade their products, so that their 8at gearbox can further improve fuel efficiency and performance, so as to ensure the competitiveness of their products in the market. Although many countries have already announced the ban on fuel vehicles, which has led to the road of electrification in the automobile industry. In other words, with the popularization of automobile electrification, the position of gearbox in the automobile industry will gradually fade, but according to ZF's prediction for the current automobile industry, at least 70% of new cars will still be equipped with internal combustion by 2030 This also proves that the mechanical gearbox also has certain market demand. In the current ZF product list, the 8at gearbox of 8HP series has developed to the third generation. The power of this generation of gearbox is obvious to all, dominating the high-end market, which is beyond the reach of other friends. However, on the global science and technology day, ZF has come up with a new generation of 8at gearbox, which is a step closer to the current third generation of 8at gearbox. The fourth generation gearbox of ZF is mainly developed in the face of electrified models. The codes are 8hp60 and 8hp80. It covers the range of 600nm-1000nm in the maximum bearing torque, and has the suffix of conv, MH and pH respectively according to the different matching electrical systems. For the fourth generation 8zt gearbox produced by ZF, compared with the previous three generations, it is not only an important part of the vehicle transmission scheme, but also a fully electrified modular innovation solution. It can not only be used in plug-in models, but also for light mixed and traditional fuel oil. In the mechanical part of the fourth generation zf8at gearbox, it is still composed of four sets of planetary gears and five sets of shifting elements. The main optimization is not limited to the optimization of the internal gear shafting. After all, the zf8at gearbox has undergone three generations of design innovation and process grinding, and has basically become very excellent in mechanical structure. ZF makes the fourth generation gearbox more possible through the use of electrical technology. It focuses on the integrated and modular design with gearbox and electrification, the optimization of accessory system and the redesign of electrical system. In the fourth generation gearbox, the light hybrid technology is directly integrated, which is very worthy of expectation for many manufacturers who lack outstanding technical reserves in the field of hybrid. In the traditional 8at gearbox of ZF, the function of light mixing is basically realized through BSG motor (P0), and the maximum bearing torque range of gearbox is also in two ranges of 600nm and 800nm. In the fourth generation of 8at gearbox introduced by ZF, it is mainly divided into light hybrid 8at with 48V electrical system, code 8hp60mh mhev and P2 plug-in hybrid 8at (motor maximum power 160kW, maximum 218 horsepower, peak torque 450nm), code 8hp80ph PHEV, the P2 type plug-in hybrid gearbox, can make the car in a high-performance output state and realize high-speed driving even when the internal combustion engine output is not used. The biggest highlight of ZF's fourth generation gearbox is that it can achieve high integration and electrification of the gearbox. In the case that the size and weight of the gearbox are not greatly improved, mhev and PHEV series products are derived, and there is too much loss in the torque bearing capacity after the gearbox height is not integrated into the motor. In fact, as early as a few years ago, ZF had intended to integrate the motor in the gearbox to achieve the electrification of the gearbox. After the test on the third generation gearbox, the power of the adaptive motor on the fourth generation gearbox was increased from 15kw-100kw in the third generation to 24kw-160kw. In the light hybrid 8at of 48V electrical system, it is officially announced that it has always existed in the form of light hybrid. The 48V auxiliary drive system can be installed in different positions of the transmission system, with the maximum power of the auxiliary motor up to 25kW, which can participate in the operation under almost all working conditions of the vehicle. In addition to improving the fuel economy, it can provide assistance in the process of vehicle startup and acceleration Power, so that the engine at all times in the best working condition greatly reduces the engine's pollutant emissions. In the new generation of PHEV version 8at gearbox, a set of self-developed motor is installed. In this set of self-developed motor by ZF, a method called "hairpin technology" is adopted. By welding copper bar instead of rewinding copper wire, the copper filling level is greatly improved. This "hairpin technology" can significantly improve the power density of gearbox without increasing the volume of gearbox Compared with the traditional hybrid gearbox, the new generation hybrid 8at gearbox can match the engine with higher power under the same package size. For this directly integrated packaged hybrid gearbox, in addition to directly solving the embarrassment of some manufacturers without hybrid technology, in terms of the gearbox itself, the electronic control unit is fully integrated into the transmission housing, reducing the problem of wiring harness layout, improving safety, and also saving assembly time and reducing maintenance costs in the assembly process of the main engine plant , guarantee quality problems, these advantages are very popular for many automobile manufacturers. In addition, ZF optimizes the centrifugal bell type vibration damper developed by ZF and applies it to the new hybrid 8at gearbox, which can achieve quieter and more efficient operation of the hybrid system, making the driver almost unable to feel the transition of the power system from electrical operation to internal combustion engine operation. For the new generation of packaged hybrid 8at gearbox introduced by ZF, it is positioned at the high-end (high-performance) hybrid vehicle, and the matching engine is also a high-power engine. Therefore, considering the heat dissipation system of the gearbox, a new adjustment has been made, which is different from the internal combustion engine used in the previous generation of gearbox, which directly drives the high-efficiency mechanical vane pump and the electric driven electronics The double oil supply system composed of pump (accumulator) is a single power shunt pump. When the internal combustion engine is shut down, the pump will be driven by a small, directly connected motor to meet the hydraulic requirements under various working conditions. When the transmission assembly is in different power output environment, the control of the diverter pump is not only more efficient, but also helpful to improve the efficiency of the hybrid system operation. Compared with the electric pressure actuator used in the past, the biggest advantage of this kind of electric control diverter pump technology matching with the direct shift valve is that it can not use the auxiliary piston and bushing. The advantage brought by this combination can not only save the internal integration space of the gearbox, but also the most important point is that in terms of the requirements of the gearbox oil, the last generation gearbox will be equipped in the ready state The required 3.1l, to the new generation of transmission is only 1.8L. Since it is a gearbox integrated with hybrid power, its emission performance has to be improved. According to the official test data, taking a 2.0L test vehicle as an example, using P2 mhev 8at can reduce the CO2 emissions of 15g / km. For ZF fourth generation gearbox, if there is no accident, it will start production in salbrucken, Germany, in 2022. However, it has been reported that both Fiat Chrysler Group and ZF have signed a large purchase order for new generation 8-speed automatic gearbox. Meanwhile, ZF will also launch more hybrid models with ZF hybrid transmission scheme through BMW, an old partner in the picture, so as to open up the reputation of new gearbox in the market and gain the share of China and the United States, two major markets.
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