Magnetic particle clutches and brakes
MAGNEBRAKE Applications
See below for MAGNEBRAKE engineering calculations on the following applications:
Magnetic Particle Brake on a Non-Contact Unwind
Magnetic Particle Brake for Controlled Deceleration
Magnetic Particle Brake on a Non-Contact Unwind
Web Force (F) = 12 lbs.
Web Speed (V) = 200 fpm
Core Dia. (d) = 3 in.
Full Roll Dia. (D) = 30 in.
1. Calculate Torque (T)
T = Force x Radius
T Start = 12 lbs. x (30in. / 24in) = 15 lb. ft.
T Finish = 12 lbs. x (3in. / 24 in.) = 1.5 lb. ft.
2. Calculate Speed (RPM)
RPM = Velocity / π(diameter)
RPM Start = 200 fpm / π(30 in. / 12 in.) = 25 rpm
RPM Finish = 200 fpm / π(3in. / 12 in.) = 255 rpm
3. Calcualte Slip Watts (SW)
SW = T x RPM / 7.04
SW Start = 15 lb. ft. x 25 rpm / 7.04 = 53 watts
SW Finish = 1.5 lb. ft. x 255 rpm / 7.04 = 54 watts
4. From Slip Watts vs RPM Curves
The 25MB90S will dissipate 140 watts at 255 rpm
5. Select the 25MB90S
Magnetic Particle Brake for Controlled Deceleration
Inertia of Load (WK²) = 50 lb. ft.²
Speed of Load = 150 rpm
Time to Stop (t) = 5 sec.
1. Calculate Torque (T)
T = WK²(rpm) / 308(t)
T = 50(150) / 308(5)
T= 5 lb. ft.
2. Calculate Slip Watts (SW)
SW = T x RPM / 7.04
SW = 5 lb. ft. x 150 rpm / 7.04
SW = 106 watts
3. From Slip Watts vs RPM Curves
The 25MB90S will dissipate 120 watts at 150 rpm
4. Select the 25MB90S
Quick Selection - Heat Dissipation (Slip Watts) vs Speed (RPM)
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