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.
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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
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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
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4. From Slip Watts vs RPM Curves
The 25MB90S will dissipate 140 watts at 255 rpm
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5. Select the 25MB90S
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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.
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2. Calculate Slip Watts (SW)
SW = T x RPM / 7.04
SW = 5 lb. ft. x 150 rpm / 7.04
SW = 106 watts
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3. From Slip Watts vs RPM Curves
The 25MB90S will dissipate 120 watts at 150 rpm
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4. Select the 25MB90S
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Quick Selection - Heat Dissipation (Slip Watts) vs Speed (RPM)
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