The transmission structure of new energy vehicles can be classified according to different technical routes and design concepts. The following are the answers directly output in the format of 1, 2, and 3:
1. Single speed transmission: Structural features: The single speed transmission has a simple structure and is mainly composed of two-stage gear transmission, with the second stage gear transmission integrated with a differential. This type of transmission has low cost and high transmission efficiency, and is a common configuration in new energy vehicles. Reduction mechanism: Reduction mechanisms mainly have two basic structures: cylindrical gear reduction and planetary gear reduction. Application examples: Chevrolet Bolt, Audi e-tron and other models all use single speed transmissions.
2. Two speed transmission: Technical route: There are various technical routes for two speed transmissions, including synchronizer shifting, single clutch structure, dual clutch structure, and planetary gear structure. Synchronizer shifting: The structure is simple and compact, the technology is mature, and the transmission efficiency is high, but there is a power interruption during shifting. Single clutch structure: With a large volume and heavy weight, it is suitable for large pure electric vehicles, but there is no specific model for use yet. Dual clutch structure: The manufacturing and research and development difficulty is relatively low, and it is widely used in hybrid transmissions, but the heat dissipation is poor and the failure rate is high. Currently, there is no pure electric vehicle model in use. Planetary gear structure: compact structure, strong impact resistance, large transmission ratio, high transmission efficiency, but difficult to manufacture and install. Porsche Taycan, Changan CS75 PHEV and other models have adopted this technology. Application examples: BMW i8 hybrid car, GKN two speed transmission, etc.
3. Integrated transmission: Three in one solution: The assembly components of the motor, electronic control, and reduction mechanism are integrated, such as the "motor+reducer+motor controller" three in one solution, as well as the more advanced "multi in one" solution, which integrates more functions such as charging machine, branch converter, etc. Advantages: Compact structure, high power density, high system efficiency, simple installation, can provide overall solutions. Application examples: Porsche Taycan's rear axle powertrain, GKN three in one assembly, ZF three in one assembly, etc.
The transmission technology of new energy vehicles is constantly developing, and new structures and design schemes are emerging one after another. The above information is based solely on currently available knowledge and information, and the actual situation may vary due to technological advancements and market changes.