Vehicle transmission with an inter-axle differential and method for operation of said inter-axle differential

A method for operation of a vehicle transmission system, comprising:

• operating an inter-axle differential to selectively enable speed differentiation between a front axle and a rear axle based on one or more vehicle operating conditions;
• wherein the inter-axle differential is included in the vehicle transmission system that comprises:
• a first planetary gear set rotationally coupled to a second planetary gear set;
• a first electrical machine rotationally coupled to a sun gear in the first planetary gear set;
• a second electrical machine rotationally coupled to a sun gear in the second planetary gear set;
• and
• the inter-axle differential including a third planetary gear set selectively rotationally coupled to the first planetary gear set and the second planetary gear set;
• wherein the vehicle transmission system further comprises:
• a first mechanical power take-off rotationally coupled to an input shaft through a countershaft gear;
• and
• a second mechanical power take-off coupled to a clutch configured to rotationally couple and decouple the first planetary gear set from the second mechanical power take-off.

An electro-mechanical infinitely variable transmission (EMIVT) system, comprising:

• a first planetary gear set rotationally coupled to a second planetary gear set;
• a first electrical machine rotationally coupled to a sun gear in the first planetary gear set;
• a second electrical machine rotationally coupled to a sun gear in the second planetary gear set, wherein the first and second electrical machines are configured to rotationally couple to an internal combustion engine;
• a first mechanical power take-off rotationally coupled to the engine through a countershaft gear;
• a second mechanical power take-off coupled to a clutch configured to rotationally couple and decouple the first electrical machine from the second mechanical power take-off;
• and
• an inter-axle differential including a third planetary gear set rotationally coupled to a front axle and a rear axle, selectively rotationally coupled the first planetary gear set and the second planetary gear set, and configured to enable and disable speed differentiation between the front axle and the rear axle.