The included angle between the sides of v belt is

MODULE TITLE : MECHANICAL PRINCIPLES

TOPIC TITLE : POWER TRANSMISSION

LESSON 2 : V-BELT DRIVES

MP - 3 - 2

© Teesside University 2011

Published by Teesside University Open Learning (Engineering)

School of Science & Engineering

Teesside University

Tees Valley, UK

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A more efficient transmission of power is achieved by the use of

vee-belts and grooved pulleys. The above photograph, reproduced

by kind permission of Fenner's, shows a multi V-belt drive from an

electric motor to a pump.

Teesside University Open Learning (Engineering)

© Teesside University 2011

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INTRODUCTION ________________________________________________________________________________________

We studied flat belt drives in the preceding lesson and it should be clear that

more power is transmitted if the 'effective tension', i.e. the difference in tension

between the tight and slack sides of the belt (F1 – F2) can be increased. This

can be achieved by using V-section belts and matching grooved pulleys.

V-belts grip on the side and not the bottom. The wedging effect increases the

reaction force between the pulley and the belt is due to increasing the friction

surface area. Therefore, more power can be transmitted compared with that

when using flat belts.

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YOUR AIMS ________________________________________________________________________________________

After studying this lesson, you should be able to:

• list the factors that govern the power transmitted by a flat belt drive

• apply belt tension equations for V-belt drives.

1

Teesside University Open Learning (Engineering)

© Teesside University 2011

________________________________________________________________________________________

V-BELT DRIVES ________________________________________________________________________________________

If a V-belt in conjunction with a grooved pulley is used instead of a flat belt

then the 'normal' reaction between the belt and the pulley is increased by the

'wedging action' of the V-belt in the groove.

FIG. 1