An important consideration when selecting a power transmission drive is

• A. Torque
• B. Horsepower
• C. Speed
• D. All of the above are important considerations when selecting a power transmission drive.

Answer: (D)

Torque, horsepower, and speed all come into play when sizing a power transmission drive. Torque tells you the turning force the system requires at the load and how much resistance the drive must overcome; if the drive can’t deliver enough torque, the load will stall or slip, and components may overheat. Horsepower represents the overall power the system needs, which depends on both torque and speed and must account for efficiency and startup surges. Speed determines the target output RPM, guiding the required gear ratio and motor selection so the driven equipment runs at the correct rate for the process. Because power is essentially torque times speed, these factors are tightly linked, and ignoring any one leads to under- or over-sizing. So all of these considerations must be taken into account.