🔍 Key Concepts

• Jacking system mechanics – how vertical motion is produced using rotating parts • Gear terminology – difference between a gear, shaft, coupling, and joint • How torque is transmitted from a motor to a lifting screw or rack

💭 Think About

• Think about which component in a jacking system actually meshes with teeth to create lifting motion. • Ask yourself: which option describes a driving element that engages with another toothed part, rather than just connecting two shafts flexibly? • Consider where you would find this part: inside a gearbox, or in an elastic connection between rotating parts?

✅ Before You Answer

• Identify which choice specifically relates to gears and toothed wheels, not flexibility. • Eliminate all options that mainly describe flexible connections rather than solid gear elements. • Picture a basic gear train: which term among the options is used for the small gear that drives a larger gear or rack?