Technical Information
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9
Torque:
T = FR
(1)
where:
T = Torque (lbft)
F = Force (lb)
R = Radius, or distance that the force is from the
pivotal point (ft)
Linear to rotary motion:
V
N =
(2)
0.262D
where:
N = Speed of shaft rotation (rpm)
V = Velocity of material (fpm)
D = Diameter of pulley or sprocket (in)
Horsepower:
Rotating objects:
TN
P =
(3)
5250
where:
P = Power (hp)
T = Torque (lbft)
N = Shaft speed (rpm)
Objects in linear motion:
FV
P =
(4)
33000
where:
P = Power (hp)
F = Force (lb)
V = Velocity (fpm)
Accelerating torque and force:
Of rotating objects:
(WK2) DN
T =
(5)
308t
where:
T
= Torque required (lbft)
WK2 = Total inertia of load to be accelerated (lbft2)
See formulas 7, 8, 9 and 10
DN = Change in speed (rpm)
t
= Time to accelerate load (sec)
Objects in linear motion:
W DV
F =
(6)
1933t
where:
F
= Force required (lb)
W
= Weight (lb)
DN = Change in velocity (fpm)
t
= Time to accelerate load (sec)
Moment of Inertia
Solid cylinder rotating about its own axis
1
WK2 = WR2
(7)
2
where:
WK2 = Moment of inertia (lbft2)
W
= Weight of object (lb)
R
= Radius of cylinder (ft)
3) Basic Engineering Information
The following engineering information will help solve technical problems frequently encountered in designing
and selecting power transmission components and systems.
R
V
N
D