QBL4208 Manual (V1.03 / 2010-NOV-03)

12

Copyright © 2010, TRINAMIC Motion Control GmbH & Co. KG

6 Motor sizing

For the optimum solution it is important to fit the motor to the application. The three key parameters

are peak torque requirement, RMS torque requirement and motor velocity.

6.1 Peak torque requirement

Peak torque T

F

L

J

P

T

T

T

T







The torque due to inertia is the product of the load (including motor rotor) inertia and the load

acceleration:

a

J

T

J





The torque due to the load is defined by the configuration of the mechanical system coupled to the

motor. The system also determines the amount of torque required to overcome the friction.

6.2 RMS torque requirement

Root-Mean-Square or RMS torque is a value used to approximate the average continuous torque

requirement. Its statistical approximation is with

t1: acceleration time

t2: run time

t3: deceleration time

t4: time in a move









4

3

2

1

3

2

F

L

J

2

2

F

L

1

2

P

RMS

t

t

t

t

t

T

T

T

t

T

T

t

T

T























