THE ORIGINAL MAGNETIC PARTICLE SPECIALISTS

# Magneclutch® Engineering Calculations

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
Quick Selection - Heat Dissipation (Slip Watts) vs. Speed Chart (RPM)

## Magnetic Particle Clutch on a Powered Rewind Web Force (F)Web Speed (V)Core Diameter (d)Full Roll Diameter (D)Motor Speed
3.5 lbs. 1490 fpm 3.25 in. 16 in. 1750 rpm
##### 1. Calculate Torque

T = F x r
T Start = 3.5 lbs. x 3.25/24 ft. = 0.5 lb.-ft.
T Finish = 3.5 lbs. x 16/24 ft. = 2.3 lb.-ft.

##### 2. Calculation Speed

N = V/πd
N Start = 1490 / π x 3.25/12ft. = 17500 rpm.
N Finish = 1490 fpm / π x 16/12 ft. = 356 rpm.

##### 3. Calculate Slipwatts

SW = T x N Slip / 7.04
SW Start = 0
SW Finish = 2.3 lb.-ft. x (1750 - 356 rpm) / 7.04 = 455 Watts

##### 4. From Slipwatts vs rpm curves

The 10MC90B-20 will dissipate 500 Watts at 1750 rpm.

## Magnetic Particle Clutch for Overload Protection Torque Required at Conveyor (T)Speed of Conveyor Drive Roll (N)MotorGear Bpx Ratio
20 ft. lbs. 175 rpm 1 hp @ 1750 rpm 10:1.
##### 1. Calculate Torque at Clutch

T = T Req + Ratio
T = 20 lb.-ft. + 10 = 2.0 lb.-ft.

##### 2. Calculation Speed at Clutch

N = N Req x Ratio
N = 175 rpm x 10 = 1750 rpm

##### 3. Calculate Slipwatts

SW = T x N Slip / 7.04
a. In normal operation, SW = 0
b. When a jam-up occurs: SW = 2.0 x 1750 / 7.04 = 497 Watts

##### 4. From Slipwatts vs rpm curves

The 10MC90B-20 will dissipate 500 Watts at 1750 rpm

## Magnetic Particle Clutch for Dynamometer Testing 1/4 - 1 hp 1750 rpm
##### 1. Calculate Torque

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 Slipwatts

SW = T x N slip / 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 Slipwatts vs rpm curves

The 10MCA90B-20 will dissipate 785 Watts at 1750 rpm.