Full load motor torque  |
Horsepower (P), hp
Shaft speed (N), rpm
5252 = Constant
|
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Average dynamic braking torque  |
Total inertia reflected to brake 
Shaft speed at brake (N), rpm
Desired stopping time (t), seconds
308 = Constant
|
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Static torque (T), lb-ft |
Force (F), lb
Pulley or drum radius, (R), ft
|
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Overhauling dynamic torque reflected to brake shaft .JPG.aspx) |
Weight of overhauling load (W), lb
Linear velocity of descending load (V), ft/min
Shaft speed at brake (N), rpm
0.158 = Constant
|
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Static torque of brake  |
Dynamic braking torque required 
0.8 = Constant (derating factor)
|
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Inertia of rotating load reflected to
brake shaft .JPG.aspx)
|
Inertia of rotating load .JPG.aspx)
Shaft speed at load 
Shaft speed at brake .JPG.aspx)
|
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Equivalent inertia of linear moving load
reflected to brake shaft .JPG.aspx)
|
Weight of linear moving load (W), lb
Linear velocity of load (V), ft/min
Shaft speed at brake .JPG.aspx)
2 = Constant
|
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Kinetic energy of rotating load,  |
Inertia of rotating load reflected to brake shaft
Shaft speed at brake .JPG.aspx)
5875 = Constant
|
.JPG.aspx?width=100&height=37) |
Kinetic energy of linear moving load .JPG.aspx) |
Weight of load (W), lb
Linear velocity of load (v), ft/sec
g = Gravitational acceleration constant 
|
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Change in potential energy (PE), ft-lb |
Weight of overhauling load (W), lb
Distance load travels (s), ft
|
PE = Ws |
Total energy absorbed by brake  |
Total linear kinetic energy 
Total rotary kinetic energy 
Potential energy converted to kinetic energy
(PE), ft-lb
|
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Thermal capacity required for rotational or linear
moving loads (TC), hp-sec/min
|
Total system inertia reflected to brake shaft
Shaft speed at brake 
Number of stops per minute (n), not less
than one 
|
.JPG.aspx?width=110&height=41) |
Thermal capacity required for overhauling loads
(TC), hp-sec/min
|
Total energy brake absorbs .JPG.aspx)
Number of stops per minute (n), not less
than one 550 = Constant
|
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Linear velocity, ft/min |
N = rpm
Diameter (D), ft
|
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