Basic Mechanical Engineering (3110006)

Velocity ratio:

• The velocity ratio of a belt drive is defined as the ratio of the speed of the driven pulley to the speed of the driving pulley.

Effect of slip on transmission:

• Result of belt slipping is to reduce the velocity ratio of the system and decrease in efficiency of transmission.

Effect of creep on transmission:

• When the belt passes from slack side to tight side, a certain portion of the belt extends and it contracts again when the belt passes from tight sight to slack side.
• Due to these changes in length, there is a relative motion between the belt and the pulley surfaces. This relative motion is called as creep.
• The total effect of creep is to reduce slightly the speed of the driven pulley or follower.