Multi-speed hybrid transmission and transmission operating method

A method for operating a hybrid transmission system, comprising:

• during a first drive mode, transferring mechanical power between an electric machine and an electric drive interface gear in a multi-speed gearbox, wherein the electric drive interface gear is located axially between two gears on an outer primary shaft;
• wherein the multi-speed gearbox includes:
• a dual-clutch clutch assembly that selectively couples an ICE to the outer primary shaft or an inner primary shaft;
• and
• an output shaft that includes an output shaft gear which is fixedly coupled thereto meshes with a first gear on a secondary shaft;
• wherein the inner primary shaft and the outer primary shaft are concentrically arranged and the inner primary shaft extends through the outer primary shaft;
• wherein the electric drive interface gear is directly fixedly coupled to a second gear;
• wherein the electric drive interface gear meshes with a third gear this is idly mounted on the secondary shaft;
• and
• wherein the second gear meshes with a fourth gear this is idly mounted on the secondary shaft.

A method for operating a dual-clutch hybrid transmission system, comprising:

• during a hybrid drive mode, transferring mechanical power between an electric machine and an electric drive interface gear idly mounted on an outer primary shaft and meshing with a first gear that is idly mounted on a secondary shaft;
• and
• selectively, transferring mechanical power between the electric drive interface gear and an inner primary shaft via an electric drive clutch that is coaxial to the inner and outer primary shafts;
• wherein the electric drive interface gear is located axially between two gears on the outer primary shaft;
• wherein the dual-clutch transmission system comprises an output shaft that includes an output shaft gear which is fixedly coupled thereto meshes with a second gear on the secondary shaft;
• wherein the inner primary shaft and the outer primary shaft are concentrically arranged and the inner primary shaft extends through the outer primary shaft;
• wherein the electric drive interface gear is directly fixedly coupled to a third gear;
• wherein the second gear meshes with a fourth gear this is idly mounted on the secondary shaft.