Transmission, single-clutch powertrain system, and method for operating a single-clutch powertrain system

A method for operating a single-clutch powertrain system for hybrid vehicles, wherein the powertrain system comprises a first electric motor, a second electric motor, an internal combustion engine, a transmission, and a clutch, wherein the transmission comprises a first input gear shaft, a second input gear shaft, an intermediate gear shaft and an output gear shaft, wherein the first input gear shaft comprises a first torque transmission member, and the second input gear shaft comprises a first gear wheel, wherein the intermediate gear shaft comprises a second gear wheel, and a third gear wheel, wherein the output gear shaft comprises a fourth gear wheel and a second torque transmission member, wherein the method comprises the steps:

• connecting the first electric motor to the first input gear shaft, the second electric motor to the second input gear shaft, and the internal combustion engine to the first input gear shaft or the second input gear shaft via the clutch, wherein the clutch is selectively connecting the internal combustion engine to and disconnecting the internal combustion engine from the first input gear shaft or the second input gear shaft;
• when receiving a command to operate the powertrain system with a first gear ratio, transferring torque from the second input gear shaft to the output gear shaft via the intermediate gear shaft for providing the first gear ratio, wherein the first gear wheel is interacting with the second gear wheel and the third gear wheel is interacting with the fourth gear wheel;
• and
• when receiving a command to operate the powertrain system with a second gear ratio, transferring torque from the first input gear shaft directly to the output gear shaft for providing the second gear ratio, wherein the first torque transmission member is interacting with the second torque transmission member via a flexible member.