Instead of using an additional clutch or other transmitting elements, the existing bevel gears of the differential are used to disconnect the drive train from the vehicles wheels.
Sales figures of vehicles with all-wheel drive are constantly on the rise, especially because of the ever-growing popularity of the SUV segment in the passenger vehicle market. To increase fuel efficiency and to reduce the CO2-footprint, most of these vehicles use some sort of AWD-Disconnect system. Such systems typically use a dog clutch or sleeve in combination with a multi plate friction clutch to bring certain parts of the AWD drive train to a standstill. The vehicle then operates in a more efficient 2-wheel drive mode and AWD is only activated when road conditions or performance requirements demand for it.
Instead of introducing new and costly force transmitting elements like dog clutches or sleeves, the existing bevel gears of the differential are positioned in a axially moveable way. When engaged, the differential functions just as any normal bevel gear differential. When disengaged, the bevel gears are moved outwards, so that they no longer mesh with their counterparts and the side shafts can rotate freely while the differential housing and its connected drive train elements (e.g. cardan shaft, gears, electric motor, ...) are at a standstill.
Compared to known state-of-the-art disconnect systems, the invented solution has the following benefits:
- No additional tooth system to be manufactured
- No additional torque transmitting elements required
- Reduction of remaining drag torque (compared to other disconnect systems)
all-wheel drive (AWD) train