Parker EY Series - Page 14

14 – Pvd3675_Gb_Ey_Septembre_2017
Illustration :
Acceleration-deceleration torque: 10 Nm for 0,1 s.
Resistant torque: 1 Nm during all the movement.
Max-min speed: ± 2800 rpm during 0,2 s.
Max torque provided by the motor: 11 Nm.
rms torque: 6 Nm.
The maximal torque M
i
delivered by the motor at each segment i of movement is
obtained by the algebric sum of the acceleration-deceleration torque and the resistant
torque. Therefore, M
max
corresponds to the maximal value of M
i
.
Selection of the motor :
The motor adapted to the duty cycle has to provide the rms torque M
rms
at the rms speed
(*) without extra heating. This means that the permanent torque M
n
available at the
average speed presents a sufficient margin regarding the rms torque M
rms.
(*) rms speed is calculated thanks to the same formula as that used for the rms torque.
The mean speed cannot be used (in general mean speed is equal to zero).
Only use the rms speed.
-20
-15
-10
-5
0
5
10
15
20
0.0 0.2
0.4
0.6 0.8
1.0 1.2
Time [s]
Torque [Nm]
-4000
-3000
-2000
-1000
0
1000
2000
3000
4000
Speed [rpm]
motor torque [Nm]
rms average torque [Nm]
speed [rpm]
rms average speed [rpm]
∑
=
∆Ω=
Ω
n
i
iirms
t
T
1
2
*
1