Lenze DSD - Manual (Page 217)

Lenze · Drive Solution Designer · Manual · DMS 4.2 EN · 12/2013 · TD23
217
7 Applications
7.22 Winding drive for rewinder/unwinder
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7.22.6.5 Max. material width
Determining the material width from the mass and the diameter of the reel
The drive can also be dimensioned if only the mass, the minimum and the maximum reel diameter
are known.
DSD uses the data of the application to calculate the moment of inertia of the reel and uses this val-
ue for the further dimensioning. The formula [7-237] for calculating the moment of inertia shows
the quantities used for the description of the reel in the dimensioning process.
[7-237] Calculation of the moment of inertia
If m, d
max
, d
min
are given and ρ is approximately known, the DSD mass calculator serves to deter-
mine the max. material width b
max
iteratively.

How to determine the max. material width:
1. Click the symbol or select the ToolsMass calculator... command to open the mass cal-
culator.
• The Mass calculator dialog box is displayed:
2. In the Field selection field, select Thick-walled hollow cylinder.
3. Enter the values for the outside diameter (d
max
), inside diameter (d
min
), and density (ρ).
4. In the Length input field, change the value by approximation until the Result field displays
the required weight.
• In addition, the value for the density can be adapted to achieve an accurate result.
5. Change to the Data of the application dimensioning step and enter the determined values
for the max. material width (length) and density.
Symbol Description
b
max
Max. width of the reel.
J Moment of inertia - reel
m Mass - reel
r
a
= d
max
Max. reel diameter
r
i
= d
min
Min. reel diameter
J
m
2
----- r
a
2
r
i
2
+ ( ) ⋅ =

Note!
• The mass m
mat,max
of the reel can be seen from the sketch of the drive train in the
data of the application.
• Since the max. material width and the density are not given but have been deter-
mined iteratively, these data must be removed from the DSD protocol. Enter the mass
of the reel instead.