Selection criteria
S
E
LECT
ING CRI
T
ERIA
Sele
cti
on of
the
synchro
nou
s motor and its associated
dri
ve
5.
209
DDS
HARDWARE
Ref.1310
Third motor pre-selection
Calculation of the acceleration torque and time
The required acceleration torque is determined by the total inertia to be
moved and the needed acceleration.
The required acceleration is determined by the acceleration time t
AC
which is the time estimated for the motor to reach its rated speed from
zero rpm.
Taking the value of t
AC
from the equation:
Calculation of the needed rms torque M
RMS
The third and last motor selection requires a new data, the RMS torque.
where:
The typical values for t
AC
, t
p
and t
C
in machine tool cycle are:
Calculation of the motor peak torque M
PEAK
The required maximum torque is the sum of the friction, weight and accel-
eration torque.
For a given acceleration time, we will need specific acceleration torque
and maximum torque. The motor must be able to provide a peak torque
equal to or greater than the calculated maximum torque.
Verify that the motor chosen in previous selections meets the following
condition:
n
N
Rated motor speed .
t
AC
The time it takes the motor to go from 0 rpm to the rated speed.
M
AC
C
ELERACION
J
TOTAL
2
n
N
60 t
AC
--------------------
=
t
AC
J TOTAL
2
n
N
60 M
AC
C
ELERACION
-----------------------------------------------------------------------
=
M
RMS
M
F
M
W
M
AC
+
+
2 t
AC
T
---------
M
F
M
W
+
2 tp
T
-----
M
F
M
W
M
C
+
+
2 t
C
T
-----
+
+
=
t
AC
acceleration time.
tp
tool positioning time.
tc
Cutting time in a machine cycle.
tC
T
------
0.6
=
tP
T
-----
0.4
=
tAC
T
---------- 0
M
t
AC
t
P
t
C
t
AC
t
T
t
S
M
MAX
M
F
M
W
M
AC
+
+
=
Peak torque equal to or greater than the calculated max. torque:
M
PEAK
M
MAX
Rated torque equal to or greater than the calculated RMS value:
M
RATED
M
RMS
Summary of Contents for DDS
Page 1: ...DRIVE DDS Hardware manual Ref 1310...
Page 6: ...I 6 DDS HARDWARE Ref 1310...
Page 9: ......
Page 10: ......
Page 11: ......
Page 12: ......
Page 16: ...16 Ref 1310 DDS HARDWARE...
Page 30: ...1 DESCRIPTION 30 Description DDS HARDWARE Ref 1310...
Page 94: ...2 POWER SUPPLIES 94 Power supplies DDS HARDWARE Ref 1310...
Page 188: ...3 DRIVE MODULES 188 Drive modules DDS HARDWARE Ref 1310...
Page 204: ...4 AUXILIARY MODULES 204 Auxiliary modules DDS HARDWARE Ref 1310...
Page 232: ...SELECTING CRITERIA 5 232 Selection criteria DDS HARDWARE Ref 1310...
Page 266: ...7 CABLES 266 Cables DDS HARDWARE Ref 1310...
Page 312: ...8 INSTALLATION 312 Installation DDS HARDWARE Ref 1310...
Page 326: ...9 FUNCTIONAL SAFETY 326 Functional safety DDS HARDWARE Ref 1310...
Page 354: ...10 CONNECTION DIAGRAMS 354 Connection diagrams DDS HARDWARE Ref 1310...
Page 378: ...12 SALES REFERENCES 378 Sales references DDS HARDWARE Ref 1310...
Page 384: ...13 COMPATIBILITY 384 Compatibility DDS HARDWARE Ref 1310...
Page 385: ......
