Stober PK - Page 454

Symbol Unit Explanation
t
1B,AC
ms Linking time: time from when the current is turned off until the nominal brak-
ing torque is reached with AC-side switching of the brake rectifier
t
1B,DC
ms Linking time: time from when the current is turned off until the nominal brak-
ing torque is reached with DC-side switching of the brake rectifier
t
11B
ms Response delay: time from when the current is turned off until the torque in-
creases
t
2B
ms Release time (also: disengagement time); time span from when the current is
switched off until the brake is completely released
t
dec
ms Stop time
T
el
ms Electrical time constant: ratio of the winding inductance to the winding resis-
tance of a motor: T
el
= L
U-V
/ R
U-V
t
n*
s Duration of the n-th time segment
t
O,B
ms Overexcitation time of the brake
ϑ
amb
°C Surrounding temperature
U V Voltage
U
holdB
V Withstand voltage of the brake
U
N,B
V Nominal voltage of brake
U
N,F
V Nominal voltage of the forced ventilation unit
U
O,B
V Overexcitation voltage of the brake
U
ZK
V DC link voltage: characteristic value of a drive controller
v
ax
mm/s Axial velocity
v
ax,m*
mm/s Actual average axial velocity
v
ax,m1*
– v
ax,mn*
mm/s Actual average axial velocity in the respective time segment
W
B,R/B
J Work done by friction for braking
W
B,Rlim
J Work done by friction until wear limit is reached
W
B,Rmax/h
J/h Maximum permitted work done by friction per hour with individual braking
x
2
mm Distance of the shaft shoulder to the force application point
x
B,N
mm Nominal air gap of brake
y
2
mm Distance of the shaft axis to the axial force application point
z
2
mm Distance of the shaft shoulder to the middle of the output bearing
15.1 Symbols in formulas 15 Appendix
454