alt Hacker News> BYD builds a unit with an integrated motor, differential, axle, and wheel hubs
So wait, the whole axle is solid then? Like a 1960s pickup truck but with all the weight of the motor and gearbox hanging off it too?
That must give it ridiculous unsprung weight.
Replies
sephamorr • yesterday at 10:16 PM
On the platforms I've worked with, the weight isn't the issue so much as the quantity of expensive and vibe sensitive parts that are unsprung.
numpad0 • yesterday at 10:14 PM
Looks like they do in-hub motor for buses and in-differential(like everyone else) for passenger cars?
it's not really like a 'live axle' from an older truck, it's more like a de-Dion style suspension (or dead axle).
https://en.wikipedia.org/wiki/De_Dion_suspension
you still see these in velocipede-style vehicles commonly.
and to your point : a dead axle is an effort to reduce unsprung weight compared to a live axle; it also lets you actually use alignment as a remediation for asymmetry issues rather than just pre-delivery straightening.