Lenze's new international sales structure

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Precision power distribution in all axes
The test benches of the Austrian specialist DAM do not have as much as two minutes within which
to put gearboxes through their paces during the quality assurance tests run by automotive manufac-
turers and suppliers. In terms of rotational speed and torque, these systems demand the ultimate in
performance from the Lenze servo motors deployed within them.
Whether all-wheel drive, four-wheel drive, quattro, or
4 x 4 – automobile manufacturers advertise claims that
agility and traction are significantly improved by modern
transfer gearboxes with electronically controlled multiple
disc clutches. The underlying principle is the variable
distribution of the drive torque between front and rear
wheels. To ensure that this works continuously, a quality
assurance program for the gearboxes is indispensable.
For this purpose, Dynamic Assembly Machines Anlagenbau
GmbH (DAM) in the Austrian town of Gleisdorf produces
highly specialised test benches. And it relies on
drive technology from Lenze.
Audible quality
“Every 90 seconds, a gearbox ‘falls’ from the assembly
line”, explains Robert Fandler, one of the managing directors,
along with Gerald Matzer, of DAM. As they are
checked, noise generation provides important information
as to whether the units, which weigh from 30 to 75 kg, are
of the desired quality. “Noises are a reliable indicator of
assembly defects or defectively produced components”,
says Matzer. For this test procedure, the Lenze drives in the
test bench must provide high rotational speeds: at the
input end, up to 7,500 rpm with torque from − 250 to
+ 250 Nm; at the output end, up to 2,500 rpm with torque
from − 700 to + 700 Nm. Considerably higher forces are
involved during clutch tests: forces of up to 1,600 Nm are
reached in the 0 to 700 rpm range. The central question is
always, are the forces being transferred from the multiple
disc clutches precisely and without slippage?
“In terms of mechanics and control technology, we went
to the limit. No one knew exactly where that was before-
hand. This is where our close collaboration with the
Lenze development department proved to be extremely
valuable.” Gerald Matzer, managing director of DAM
A universal test bench for the pilot production
stage
While separate test systems are used for noise and
clutches in series production, things are set up differently
in the pilot production stage. “For this purpose, we
have developed a universal test bench that covers noise
and characteristics tests.” The analytical procedures
must be close-to-production so that they can be transferred
one-to-one to higher numbers later on. In this
respect the DAM universal test bench is a versatile link
between the development phase and the beginning of
series production. Hence the test bench also has the
flexibility that allows refitting, and it offers various
gearbox fixings and contact possibilities for the motor
control devices.