...how the HF35 works.
If I understand the schematic on page 8 correctly, this might have some differences versus the AW Powersplit previously used but a lot of similarities. Difficult to tell. The AW uses a planetary gearset. The ring gear is powered by the traction motor/generator (MG2) which drives the wheels, the planet carrier is powered by the ICE, and the sun gear is connected to a second motor generator (MG1). Here's a really great demo:
If I understand the schematic of the Ford design, it looks it will operate in a very similar manner, although the location of the components might be a bit different? The ICE powers the planet carrier, the smaller motor/generator powers the sun gear. The ring gear is connected to the output via Gear 2; on the same shaft the larger traction motor/generator is connected through Gear 4.
Not sure which components are shared with other Ford transmissions, but probably more in the differential area, since the whole planetary gearset and motors are unique.
Any transmission experts out there to give us more details??