Festo DGE ZR RF Series, Repair Instructions

Page: 19 / 64

19 / 44 Festo 7DGE_ZR_RFb_en
4.1.2 Checking and setting the toothed belt pretension
The toothed belt pretension is determined by measuring the basic oscillation
(natural frequency) of the toothed belt with a fixed and freely oscillating strand
length (L). Since the freely oscillating strand length (L) cannot be measured
directly, the distance (L1) from the clamp piece (a)/clamping body (b) to one of
the drive covers is set by moving the slide. The oscillation measurement is then
carried out at this point.
Warning
The toothed belt pretension has a direct influence on the service life of the
toothed belt and the performance of the toothed belt axis. Extreme care
must therefore be exercised when checking it.
Before the toothed belt pretension can be measured, the slide must be
moved back and forth a number of times so that the toothed belt can fully
settle and differences in tension are equalised.
DGE-25/40
L
L1
DGE-63
L
L1
a
b
b
Documents
The easiest way to check the toothed belt pretension is using the toothed
belt pretension test equipment (see section
6.3 “Devices and meters” ). The
work instructions required for this as well as the setting values can be found
in the associated operating instructions in the appendix to this document.
Checking the toothed belt pretension
• Place the toothed belt axis on the work surface as shown with the slide
facing upwards.
• Lever off the cover caps at both ends from the drive covers.
Note (DGE-25 and DGE-40)
It is necessary to attach an additional clamp piece (see section 6.4 “Devices
for in-house assembly” ) with the axes DGE-25 and DGE-40 so that the toothed
belt can oscillate freely and does not strike the cylinder barrel.
• If necessary, push the relevant clamp piece through the recess in the cylinder
barrel between the toothed belt and cylinder barrel. It must touch the clamp-
ing body.