Soviet Screw-Drive Tank
No kidding, this Soviet armored military vehicle was constructed in 1970 by the Zil factory and as you can see there is are two large screws in place of tracks. This vehicle is capable of traveling through very rough terrain but the lack of a suspension system makes the vehicle quite unstable. So while this propulsion system might work for a reconnaissance vehicle, it wouldn’t be ideal for a medivac, APC or tank.
A series transmission is not needed, so a screw propulsion system has a better fuel economy, lower drivetrain, less complexity and fuel weight than the typical wheel/track system.