Split axis transmission hybrid system architecture
AssigneeZF Friedrichshafen AG
InventorJames Potter
Life of this patent
Estimating the term…
Abstract
A split-axis transmission hybrid system may include two planetary gear sets to provide two parallel torque paths from an input axis to an output axis. A secondary power source may be coupled to either the input axis or the output axis to provide torque to the system. Thus, the split-axis transmission hybrid system may provide the ratio preselection capability and the low power losses of a dual-clutch transmission and the ratio-changing control and smoothness of a traditional powershift automatic transmission, while also providing the improved efficiency and enhanced drivability of a hybrid power source arrangement.
Claims14
A transmission comprising:
- a first planetary gear set providing at least part of a first torque path from an input shaft to an output shaft;
- a second planetary gear set connected in parallel with the first planetary gear set and providing at least part of a second torque path from the input shaft to the output shaft;
- a plurality of gears configured to transmit torque selectively from the first torque path to the output shaft, and to transmit torque selectively from the second torque path to the output shaft;
- and
- a secondary output shaft coupling coupled with the output shaft and configurable to couple a secondary power source to the output shaft.
A transmission as in claim 8 wherein the starter-generator is forcibly cooled.
A transmission as in claim 8 further comprising a low-voltage capacitor, a high-voltage capacitor, a direct current-to-direct current converter, and a high-voltage energy storage system in connection with the secondary power source.
A transmission comprising:
- a first planetary gear set providing at least part of a first torque path from an input shaft to an output shaft;
- a second planetary gear set connected in parallel with the first planetary gear set and providing at least part of a second torque path from the input shaft to the output shaft;
- a plurality of gears configured to transmit torque selectively from the first torque path to the output shaft, and to transmit torque selectively from the second torque path to the output shaft;
- and
- a first torque path coupling coupled with the first torque path and configurable to couple a secondary power source to the first torque path.
A method of operating a transmission having first and second parallel, alternative torque paths between an input shaft and an output shaft, with a coupling for a primary power source with the output shaft and a coupling for a secondary power source with the output shaft, the method comprising:
- coupling a secondary power source to the output shaft;
- engaging a first planetary gear set to transmit torque along the first torque path;
- providing torque to the output shaft from the secondary power source;
- determining a change in a target transmission gear ratio;
- disengaging the first planetary gear set;
- and
- engaging a second planetary gear set to transmit torque along the second torque path.
Dependencies are inferred from the claim text.