Experiment No: 07 Date:21st July, 2014

Experiment Name: Study on VDQ pulley arrangement.

VDQ = VDQ pulley means variable diameter for quality.

There are two v-belt pulleys that are split per pendicular to axes of rotation with a v-belt

running between them. The gear ratio is changed by moving the two sheaves of on pulley

closer together and two sheaves of the other pulley farthers apart due to the v-shaped.

Cross section of the belt this causes the belt to ride higher on one pulley and lower on the

others doing this changes. The effective diameter of the pulleys . Which in turn change the

overall gear ratio. The distance between the pulleys does not changes and neither does the

length of the belt. So changing the gear ratio means both pulleys must be adjusted (one

bigger the other smaller) simultaneously in order to maintain the proper amount of tension

of the bet.

Figure: VDQ Pulley.

The Function of VDQ Pulley :

The function VDQ pulley is given that if VDQ pulley pitch radius is decreased then stitch

length increased and also GSM is decreased.

If VDQ pulley pitch radius is increased than stitch length decreased and also GSM is

increased . When this happens to one of the pulley the other pulley is performing the

operation.