Power Transmission by Belt Drives Study Mtaeria

Power Transmission by Belt Drives                                                                                                                                       Power Transmission by Belt Drives

Power Transmission by Belt Drives Study Mtaerial

A common and simple method of transmitting power from one shaft to another is by means of a belt passing over pulley wheels which are keyed to the shafts,

Typical applications include an electric motor driving a lathe or a drill, and an engine driving a pump or generator.

For a belt to transmit power between two pulleys there must be a difference in tensions in the belt on either side of the driving and driven pulleys. For the direction of rotation shown in Figure 1 F₂ > F₁

FIG 1

The torque T available at the driving wheel to do work is given by:

T = (F₂- F₁)  rx     Nm

where
F₂  is tension force in belt on driving pulley
F₁   is tension force in belt on driven pulley
rx       is radius  of driving pulley 

and the available power P is given by:

P = T𝟂= .(F₂ − F₁) /rx 𝜔𝚡  watts

where 

𝜔𝚡  is angular velocity of driving pulley

re                                                              T = P / (2 𝜋  n )

the linear velocity of a point on the driver wheel 

vx = rx ωx

Similarly, the linear velocity of a point on the driven wheel

 vy = ry ωy

Assuming no slipping,                                vx = vy i.e. rx ωx = ry ωy

                                   rx (2 𝜋 nx )   =  ry  ( 2 𝜋 ny )

where 

nx  is rotating  speed  of driving pulley

ny  is rotating speed of driven pulley 

ry  is radius  of driving pulley 

Percentage efficiency= (useful work output/power input) × 100

see  http://mechasource.blogspot.com/2018/03/belt-drives.html