Parker GVM Series - Page 12

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18-06-08 PVD3668_GB_GVM_June_2018
Selection of the motor :
The motor corresponding 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 with 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
Furthermore, each Mi and speed associated Ωi of the duty cycle has to be located in the
operational area of the torque vs speed curve.
Torque
M
k
M
rms.
M
n
M
i
Ωi Ωk Ω
rms
Ωn Speed
Base speed
We are defining the base speed the knee of the continuous curve, not the knee of the peak
curve…



n
i
iirms
t
T
1
2
*
1