Innovative Dedicated Hybrid Transmission Concepts in the Next Generation of Hybrid Powertrains 08-08-01-0005

Due to the advantages of hybrid vehicles in comparison with pure electric vehicles, Hybrid Electric Vehicle (HEV)/Plug-in HEV (PHEV) no undoubtedly becomes the reasonable and practical solution in the development of vehicle electrification at the moment. Meanwhile, Dedicated Hybrid Transmission (DHT), as the especially designed hybrid transmission for HEV/PHEV, represents the development direction of hybrid vehicles.

But in the market, the well-known DHT concepts are all protected by patents by large Original Equipment Manufacturers (OEMs). How to break the patents and more importantly develop the innovative DHT concepts in the next generation is of vital importance in the development of HEV/PHEV.

In this article, firstly, the features and comparisons of different well-known DHT concepts are discussed and analyzed. The mechanical and electrical complexity are introduced to essentially analyze the advantage and disadvantage of different kinds of DHT concepts. Based on the analysis, the possibilities of different DHT concepts in the next generation are further analyzed and demonstrated. The innovative DHT are derived from the analysis. In comparison with DHT in the market, the innovative DHT concepts can on one hand break the DHT patents and, on the other hand, overcome the shortcomings of the present DHTs. Especially for the new possibilities of power-split DHT, the DHT concepts with the combined structure are newly introduced. With the combination of planetary gear set in Automatic Transmission (AT) and synchronizer/dog clutch in Dual Clutch Transmission (DCT), the advantages of both transmissions can be effectively integrated to realize the mode transition without power interrupt. In this way, the mechanical and electrical complexity of the concepts can reach an excellent balance. At last, the dynamics and economics of the new DHT concepts are further simulated and validated in the driving cycle. In conclusion, the new DHTs have many advantages both in structure and function compared with the DHTs in the market. It provides the new development direction of DHT in the next generation.