Engineering Guide CDA3000
1-5
1 Analysis of task
DE
EN
1
2
3
4
5
6
7
A
The drive unit is formed by a regulated DC drive, gearing and the screw
return thrust bearing, which absorbs the forces occurring during convey-
ing and plasticizing.
Figure 1.4 Load characteristic of the plastics extruder
Task for a new drive unit
In order to provider a higher degree of machine availability, the drive is to
be switched from DC to three-phase AC. The DC drive used to date has a
speed manipulating range of 1:1000 and an overload capacity to 200%.
M
L
= f (n)
P = f (n)
(1) DC controller
(2) DC motor
(3) Tacho
(4) Gearing
(5) Screw return thrust bearing
Figure 1.5 Old solution with DC drive
n
M
L
,
P
P
M
L
M
M
1
~
T
(1)
(2)
(4)
(5)
(3)
