The application discloses a kind of follow-up device capable of driving semi-trailer compartment longitudinal migration and the semi-trailer of application of this follow-up device.The follow-up device is located between
tractor and semi-trailer compartment, including
saddle,
crank slider mechanism, generating mechanism and driving mechanism.When semi-trailer turns, with the angle formed by
tractor cab and semi-trailer axis, driving mechanism drives
crank slider mechanism to drive multiplication planetary gear to move longitudinally backward in the tooth slot formed by fixed rack and movable rack, fixed rack drives multiplication planetary gear to rotate, so that multiplication planetary gear drives
saddle bottom plate to move longitudinally backward, realize the follow-up backward adjustment of semi-trailer compartment, expand the gap between
tractor cab and semi-trailer compartment of semi-
trailer truck;And with the relative rotation
recovery to straight running state after turning ends, driving mechanism drives generating mechanism to reset,
saddle moves longitudinally forward, again reduce the gap between tractor cab and semi-trailer compartment, and the vehicle restores to the state of reducing wind resistance.