Lenze DSD - Manual (Page 124)

7 Applications
7.9 Hoist drive with counterweight
124
Lenze · Drive Solution Designer · Manual · DMS 4.2 EN · 12/2013 · TD23
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Stationary torque
The stationary torque is calculated from the difference of the masses assessed with the reeving.
[7-98] Equation 6: Stationary torque

Tip!
The mass of the cables usually can be disregarded, since the force due to weight of the ca-
bles cancels itself out in the case of a pulley block.
For some applications the cable mass in the most unfavourable position of the hoist is quite
important (e. g. in the case of great lifting heights), so that it can be considered as the active
cable mass m
acv,Rop
.
For the drive the stationary torque, also on the pulley block, is only the mass of a simple ca-
ble, since the masses of the other cables cancel themselves out by the fixed cable rolls. The
cable mass for the counterweight can be deducted.
Ascertainment of the active cable mass
The active cable mass is ascertained by means of the mass calculator (field: cylinder) and is calculat-
ed with the following equation:
[7-99] Equation 7: Active cable mass for the stationary torque
M
sds
d
2000
------------- F
add
g
m
L
N
L
-------



⋅
m
Cbn
N
L
-------------
m
Ctw
N
Ctw
-------------- – m
acv,Rop
+ + +
 
 
 



⋅ =
m
acv,Rop
ρ
Rop
Δh 10 π
d
Rop
200
-----------
 
 
2
⋅ ⋅ ⋅ ⋅ =