eDifferential motor/differential combo for EV

[FiddlerJohn]

Does anybody see the electric parking brake sprag, pawl, pall?
Notice the wire coils are in the outside fixed stator so they don't spin. This allows for very high (10,000) rpm.

This eDifferential integrates two water-cooled permanent magnet synchronous motors (PMSM) of different dimensions, a planetary gear, a transmission for active torque distribution and, as a key element, a Schaeffler lightweight differential. The electric drives are manufactured by Schaeffler brand IDAM. The larger PMSM (up to 105 kW and 170 N·m ) provides the drive. The second PMSM, which regulates the distribution of torque, must only supply 5 kW of power in order to generate a difference in torque on the axle of up to 2000 N·m.

From: http://www.greencarcongress.com/2012/01/schaeffler-20120119.html

 

[jray3]

:? Wow, that's a lot more complex than I imagined a fixed-gear reduction unit would be! No clue on the parking pawl yet.

 

[FiddlerJohn]

Does anybody see the electric parking brake sprag, pawl, pall?

The parking sprag (pawl) might grab the disk in the center to the left of the helical gears with the very large teeth, but the sprag isn't shown. I only guessing.

There are a lot of very noisy straight cut gears. Straight cut gears 'whine' the faster they go but offer more force and less power loss. Straight cut transmissions are stronger and more efficient. Car manufacturers don't use straight cut due to the immense noise the transmission would produce. Many older manual transmissions use straight cut gears for reverse only. Therefore, going in reverse produces a whine, but forward will not.

The eDifferential helical gears must be the highest rpm.

Race cars use straight cut gears.

I suspect that all the iMiEV gears are helical except the differential, because the differential gears are low rpm and only while the car is turnings.