If the motor shaft is parallel to the indexing table, which drive is commonly used between the motor and the table?

• A. Direct drive
• B. Worm gear
• C. Belt drive
• D. Bevel gear

Answer: (B)

When you’re driving an indexing table from a motor and the two shafts run parallel, a worm gear drive is a common choice because it provides a large speed reduction in a compact setup and, importantly, resists back-driving. Placing a worm on the motor shaft and a worm wheel on the table lets a small motor achieve high torque at the table with simple alignment, which helps the table hold its position precisely when power is removed. This self-locking behavior and smooth, quiet operation are especially beneficial for accurate indexing where the table must stop at exact steps and resist unwanted movement. Direct drive would not give much reduction and could require a larger motor; belt drives can handle parallel shafts but may slip and require tensioning, and be­vel gears are intended for non-parallel (often intersecting) axes. That combination of high reduction, compact form, and positional stability makes the worm gear a preferred choice here.