Clutches 18 April, 2011

Prof. Samy J. Ebeid ١

ClutchesPart 05A - MANF 361

SJE Part 05A Clutches ١

٢SJE Part 05A Clutches

Ex 05-1 Centrifugal Clutch

1. Calculate the Horse Power that the driven machine receives at the maximum motor speedof 1000 RPM. Then determine the necessary width of the shoes.2. Plot the relationship betw een the Pow er that the machine receives and the rotational speedof the Clutch starting fromzero up to 1000 RPM.3. Present a free hand sketch for the clutch unit.

The sketch shows a centrifugal clutch unit that transmits power from an electricmotor to a machine through a flat belt drive. The clutch starts to transmit torquewhen the speed reaches 75% of the maximum motor speed (At 750 RPM the

friction surfaces just come in contact and the spring force equalizes thecentrifugal action).

Belt size 120 * 3 mm

Belt transmission efficiency 84 %

Belt transmission ratio 1 : 1

Belt Drive

Clutches 18 April, 2011

Prof. Samy J. Ebeid ٢

٣SJE Part 05A Clutches

Ex 05-1

Mean spring diameter 22 mm

Spring wire diameter 5.6 mm

Active number of coils 8

Spring wire material Swedish plain C steel 0.7 % C

Deflection of spring when motor rotates at 750 RPM 6.15 mm

Spring deflection, Y Y = 8 * F * Dm3 * N /(d4 * G)

F=spring force

Number of shoes 4

Angle of contact between shoe and drum 60˚

Working pressure between the friction surfaces at the maximum

clutch speed

0.2 MPa

Coefficient of friction between the friction surfaces 0.3

Friction surface diameter 270 mm

Clutch Springs

Clutch Shoes

٤SJE Part 05A Clutches

Ex 05-1

Clutches 18 April, 2011

Prof. Samy J. Ebeid ٣

٥SJE Part 05A Clutches

Pneumatic Geared Clutch

٦SJE Part 05A Clutches

Pneumatic Geared Clutch

Clutches 18 April, 2011

Prof. Samy J. Ebeid ٤

Maxitorq Air Clutch

٧SJE Part 05A Clutches