A rotationally locked drive assembly for a VSI crusher comprises a drive shaft 52 rotatably securable in a bearing cartridge assembly 60, the drive shaft having a tapered upper end portion 62 for forming a taper joint in cooperation with the tapered central opening 72 of a flywheel 54, a top opening key receptor 81 formed on the top surface 76 of the flywheel for receiving a locking key 56, whereby tightening of fasteners 58 secures locking key 56 in key receptor 81, presses flywheel 54 onto drive shaft 52, thereby fortifying the taper joint between the flywheel 54 and drive shaft 52, and locking drive shaft 52, flywheel 54 and locking key 56 in rotational alignment.