BECKHOFF AM2000 - Manual (Page 12)

I.8 Technical data
I.8.1 Definitions
Standstill torque M
0
[Nm]
The standstill torque can be maintained indefinitely at a speed n=0 min
-1
and rated
ambient conditions.
Rated torque M
n
[Nm]
The rated torque is produced when the motor is drawing the rated current at the rated
speed. The rated torque can be produced indefinitely at the rated speed in continuous
operation (S1).
Standstill current I
0rms
[A]
The standstill current is the effective sinusoidal current which the motor draws during
standstill to produce the standstill torque.
Rated current I
nrms
[A]
The rated current is the effective sinusoidal current which the motor draws at the rated
speed in order to produce the rated torque.
Peak current (pulse current) I
0max
[A]
The peak current (effective sinusoidal value) should not exceed 4-times the rated current.
The actual value is determined by the peak current of the servoamplifier which is used.
Torque constant K
Trms
[Nm/A]
The torque constant defines how much torque in Nm is produced by the motor with 1A
r.m.s. current. The relationship is M=I x K
T
Voltage constant K
Erms
[V/1000min
-1
]
The voltage constant defines the induced motor EMF, as an effective sinusoidal value
between two terminals, per 1000 rpm
Rotor moment of inertia J [kgcm²]
The constant J is a measure of the acceleration capability of the motor. For instance, at I
0
the acceleration time t
b
from 0 to 3000 rpm is given as:
t s
M s
x
m
xcm
J
b
[ ] =
´
´
´
3000 2
60 10
0
2
4 2
p
with M
0
in Nm and J in kgcm²
Thermal time constant t
th
[min]
The constant t
th
defines the time for the cold motor, under a load of I0, to heat up to an
overtemperature of 0.63 x 105 Kelvin. This temperature rise happens in a much shorter
time when the motor is loaded with the rated current.
Release delay time t
BRH
[ms] / Application delay time t
BRL
[ms] of the brake
These constants define the response times of the holding brake when operated with the
rated voltage from the AX2000 servoamplifier.
12 Motor series AM227..297
General
12/2001
BECKHOFF