22 / 44
Festo 7DGE_ZR_RFb_en
The frequency to be set can be calculated using the data from the following table:
Type
Weight per metre m
Freely oscillating strand length L
Pretension force F
V
DGE-25
0.0459 kg/m
24 mm + L1
1)
267 - 282 N
DGE-40
0.1179 kg/m
33 mm + L1
1
628 - 663 N
DGE-63
0.2789 kg/m
51 mm + L1
1
1,528 - 1,612 N
1)
See section
4.1.2 “Checking and setting the toothed belt pretension”
Note on measurement using the acoustic belt tension meter
If the toothed belt is excited by means of a force stimulus, the strand oscillates with its natural frequency; this dies down
reasonably quickly depending on the attenuation.
The frequency meter measures the natural frequency generated (transverse oscillation) using the acoustic operating
principle. In addition to the basic oscillation (natural frequency), harmonic oscillation can also occur. From experience it
is always the first harmonic oscillation. In other words, a further oscillation node is generated and therefore in addition
to the basic oscillation frequency, values that are twice the natural frequency can also be measured.
For this reason, several measurements should always be carried out to differentiate the necessary basic oscillation
(natural frequency) from the harmonic oscillation. Only this frequency can be used to extrapolate the force acting along
the strand.
4.1.4
Cutting the toothed belt to length
The toothed belt is ordered from the online spare parts catalogue (
) using the appropriate part
number (dependent on the size and version of the toothed belt axis).
The part number is a module number and is dependent on the size of the toothed belt axis. You must specify the stroke
and the type of slide required for your toothed belt axis in addition to the part number when ordering. The necessary
specifications can be determined from the type codes on the name plate of the toothed belt axis (see order example
below). Using this information you can calculate the necessary toothed belt length.
Cutting the new toothed belt to length
The exact length of the toothed belt in mm is twice the product of the stroke of the toothed belt axis and a factor (F).
The factor is dependent on the size and type of slide used (see table).
The stroke and the slide type can be determined from the type codes on the name plate. Check the length of the new
toothed belt and shorten it if necessary to the calculated length (2 × ( factor)), see order example:
Type
Factor F
DGE-25-…-GK
330
DGE-25-…-GV
377.5
DGE-40-…-GK
506.5
DGE-40-…-GV
576.5
DGE-63-…-GK
834
DGE-63-…-GV
949
Example: DGE-25-300-ZR-RF-LV-RK-GK
Stroke:
300 mm
Factor F:
see table
Toothed belt length = 2 × ( F) = 1,260 mm
Note
Sturdy general purpose scissors or metal shears are best for cutting the toothed belt.
Warning
Do not bend or fold the toothed belt, as this can result in damage to the tensile bodies and shorten its service life by
tearing it. Note the minimum bending radius for assembly and storage:
DGE-25: R
min
=
6 mm
DGE-40: R
min
=
10 mm
DGE-63: R
min
=
20 mm
