What is the effect of using a V-belt drive compared to a timing belt drive?

• A. V-belts provide positive engagement and better alignment; timing belts slip under load.
• B. V-belts can slip under load; timing belts provide positive engagement and better alignment; timing belts are quieter with less maintenance.
• C. Both belts provide identical performance; choose by cost only.
• D. V-belts are quieter with less maintenance than timing belts.

Answer: (B)

When comparing belt drives, the way power is transmitted matters. A V-belt relies on friction and the wedge effect to grip the pulley. Under heavy load or with misalignment, that friction can be overcome and the belt can slip, causing loss of torque transmission and changes in speed.

Timing belts, on the other hand, have teeth that mesh with matching pulley grooves. This teeth-on-groove engagement provides positive engagement, so the belt cannot slip relative to the pulley. That keeps timing and speed consistent and helps maintain alignment.

Because the teeth keep the belt from slipping and help maintain smooth, accurate motion, timing belts tend to run quieter and with less maintenance compared to V-belts, which require more tensioning and can wear or slip over time.