Magnetic particle clutches and brakes
MAGNECLUTCH Applications
See below for MAGNECLUTCH engineering calculations on the following applications:
Magnetic Particle Clutch on a Powered Rewind
Magnetic Particle Clutch for Overload Protection
Magnetic Particle Clutch for Dynamometer Testing
Magnetic Particle Clutch on a Powered Rewind
Web Force (F) = 3.5 lb.s
Web Speed (V) = 1490 fpm
Core Dia. (d) = 3.25 in.
Full Roll Dia. (D) = 16 in.
Motor Speed = 1750 rpm
1. Calculate Torque (T)
T = Force x Radius
T Start = 3.5 lbs. x 3.25in. / 24in. = 0.5 lb. ft.
T Finish = 3.5 lbs. x 16in. / 24 in. = 2.3 lb. ft.
2. Calculate Speed (RPM)
RPM = Velocity / π(diameter)
RPM Start = 1490 fpm / π x 3.25in. / 12in. = 1750 rpm
RPM Finish = 1490 fpm / π x 16in. / 12in. = 356 rpm
3. Calculate Slip Watts (SW)
SW = T x (RPM in - RPM out) / 7.04
SW Start = 0
SW Finish = 2.3 lb. ft. x (1750 rpm - 356 rpm) / 7.04 = 455 watts
4. From Slip Watts vs RPM curves
The 10MC90B20 will dissipate 500 watts at 1750 rpm
5. Select 10MC90B20
Magnetic Particle Clutch for Overload Protection
Torque Required at Conveyor (T Req) = 20 lb. ft.
Speed of Conveyor Drive Roll (N Req) = 175 rpm
Motor = 1 hp @ 1750 rpm
Gear Box Ratio = 10:1
1. Calculate Torque at Clutch (T)
T = T Req / Gear Ratio
T = 20 lb. ft. / 10 = 2.0 lb. ft.
2. Calculate Speed at Clutch (RPM)
RPM = N Req x Gear Ratio
RPM = 175 rpm x 10 = 1750 rpm
3. Calculate Slip Watts (SW)
SW = T x RPM / 7.04
SW in normal operation = 0
SW when jam-up occurs: SW = 2.0 lb. ft. x 1750 rpm / 7.04 = 497 watts
4. From Slip Watts vs RPM Curves
The 10MC90B20 will dissipate 500 watts at 1750 rpm
5. Select 10MC90B20
Magnetic Particle Clutch for Dynamometer Testing
Test Motor Size = 1/4 - 1 hp
Full Load Speed = 1750 rpm
1. Calculate Torque (T)
T = 5250 x hp / rpm
T Min = 5250 x 1/4 hp / 1750 rpm = .75 lb. ft.
T Max = 5250 x 1 hp / 1750 rpm = 3 lb. ft.
2. Calculate Slip Watts (SW)
SW = T x RPM / 7.04
SW Min = .75 lb. ft. x 1750 rpm / 7.04 = 186 watts
SW Max = 3 lb. ft. x 1750 rpm / 7.04 = 746 watts
3. From Slip Watts vs RPM Curves
The 10MCA90B20 will dissipate 785 watts at 1750 rpm
4. Select 10MCA90B20
Quck Selection - Heat Dissipation (Slip Watts) vs Speed (RPM)
