I think the timing chain drives a sprocket that drives a worm gear that drives the rotor. If chain breaks, worm gear will freewill. I think these are not interference engines... i.e. the valves wont get bent when the timing chain breaks.

Does the car not run at all?
How did it die? All the sudden?
How many miles are on it?
Was it making any special noises prior to it failing?

My 1986 190E with 98000 miles has motor noise and lack of power. I cant go over 60 mph.

Good luck.