Abstract: A speed reducer, a power system, a straddle-type rail train, and a rail transport system are disclosed. The speed reducer includes: a box body; a speed-reducing mechanism, disposed in the box body; and a support shaft, a first end of the support shaft being supported on the box body, and a second end of the support shaft being connected to a high-speed end of the speed-reducing mechanism. The speed reducer according to the present disclosure achieves a more stable connection between a drive shaft and a speed-reducing mechanism and a more stable power transmission.

Abstract: A transmission, a power-driven system, and a vehicle are provided. The transmission includes a first planetary gear mechanism, a second planetary gear mechanism, an input shaft, an intermediate shaft, a first synchronizer, and a second synchronizer. A second planet carrier in the second planetary gear mechanism is connected to an output end of the transmission. The input shaft is connected to a first sun gear. A first ring gear is connected to the intermediate shaft. The intermediate shaft is connected to a second sun gear. The first synchronizer secures a first planet carrier to a housing of the transmission or connects the first planet carrier to the first sun gear. The second synchronizer secures a second ring gear to the housing of the transmission or connects the second ring gear to the first ring gear.

Abstract: A speed reducer, a power system, a straddle-type rail train, and a rail transport system are disclosed. The speed reducer includes: a box body; a speed-reducing mechanism, disposed in the box body; and a support shaft, a first end of the support shaft being supported on the box body, and a second end of the support shaft being connected to a high-speed end of the speed-reducing mechanism. The speed reducer according to the present disclosure achieves a more stable connection between a drive shaft and a speed-reducing mechanism and a more stable power transmission.

Abstract: A transmission, a power-driven system, and a vehicle are provided. The transmission includes a first planetary gear mechanism, a second planetary gear mechanism, an input shaft, an intermediate shaft, a first synchronizer, and a second synchronizer. A second planet carrier in the second planetary gear mechanism is connected to an output end of the transmission. The input shaft is connected to a first sun gear. A first ring gear is connected to the intermediate shaft. The intermediate shaft is connected to a second sun gear. The first synchronizer secures a first planet carrier to a housing of the transmission or connects the first planet carrier to the first sun gear. The second synchronizer secures a second ring gear to the housing of the transmission or connects the second ring gear to the first ring gear.

Abstract: A power transmission system of a vehicle and a gear-shift control method are provided. The power transmission system includes a first drive assembly (101) and a second drive assembly (102). The first drive assembly includes a first automatic transmission (2) and a first motor (1) connected with the first automatic transmission (2) for outputting power to two wheels of the vehicle. The second drive assembly (102) includes a second automatic transmission (2000) and a second motor (1000) connected with the second automatic transmission (2000) for outputting power to the other two wheels of the vehicle. The first and second automatic transmission are configured to be shifted to a preset gear or a gear adjacent to the preset gear, such that when one of the first and second automatic transmission is shifted to the preset gear, the other one of the first and second automatic transmission is shifted to the preset gear or the gear adjacent to the preset gear.

Abstract: A power transmission system of a vehicle and a gear-shift control method are provided. The power transmission system includes a first drive assembly (101) and a second drive assembly (102). The first drive assembly includes a first automatic transmission (2) and a first motor (1) connected with the first automatic transmission (2) for outputting power to two wheels of the vehicle. The second drive assembly (102) includes a second automatic transmission (2000) and a second motor (1000) connected with the second automatic transmission (2000) for outputting power to the other two wheels of the vehicle. The first and second automatic transmission are configured to be shifted to a preset gear or a gear adjacent to the preset gear, such that when one of the first and second automatic transmission is shifted to the preset gear, the other one of the first and second automatic transmission is shifted to the preset gear or the gear adjacent to the preset gear.