1. V-BELTS
V Belts are flexible machine elements used for the transmission of power over comparatively long distances. These belts provide a compact, resilient transmission and are used extensively in automotive and industrial drives for fans, generators, pumps etc. They are specified by the belt type and section identification, and also by the circumferential length of the belt. On page 2, there is a diagram of the two types of V Belt construction.
HOW DO V BELTS WORK?
Only the angular sides of a V Belt come in contact with the sides of the pulley groove, and most of the belts (excluding the classical cross sections) run approximately flush with the top of the pulley. See diagram A.
The pulley groove must be deep enough to provide a space below the belt, ensuring that belt contact is on the sides only.
This space also assists in heat dissipation from the belt. The groove angle of the pulley is made slightly smaller than the belt section angle and the belt tends to wedge itself into the groove. Additionally, when tension is applied to the belt, the compression zone underneath the reinforcing cords will tend to bulge into the pulley side walls.
Therefore this 'wedging' of the belt into the pulley groove enables the belt to grip the pulley and thus, transmit power.
ADVANTAGES:
V Belt drives provide many maintenance advantages that help in the daily struggle to reduce equipment repairs and to hold forced downtime to the lowest possible level.
• They are an economical method of transmitting power.
• They are clean - No lubrication is required.
• They are efficient - Drive efficiency averages 94.98%.
• They possess smooth starting and running characteristics.
• They cover extremely wide horsepower ranges.
• They permit a wide range of driven speeds, using standard electric motors.
• They dampen vibration between driving and driven machines.
• They are quiet in operation.
• They act as a "safety fuse" in the power drive because they refuse to transmit a severe overload of power, except for a very brief time.
• V Belts wear gradually, making preventative or corrective maintenance simple and easy to plan in advance.