Pratissoli VFH Serie Manuel D'utilisation Et D'entretien page 30

9.12 Definition of static pull to apply on belts
Static pull depends on:
a) The wheelbase between the two pulleys (belt length).
b) The load due to static pull of the belt.
c) The number of belts.
d) The winding angle of the smallest pulley.
e) Average speed.
f ) Etc.
Values of the static pull to be applied can be obtained from
the diagram in Fig. 12 for belts with a XPB profile in relation to
the wheelbase.
Lf= Wheelbase mm
Conclusion: with a wheelbase of 600 mm and with a
dynamometer, loading the belt branch with 75 N as indicated
in Fig. 13, a "te" bend of approximately 10.8 mm is obtained.
Lf = Wheelbase
te = Belt bend
Fe = 75 N Dynamometer load
Note . Unless otherwise stated by the supplier of the belts,
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control of proper pull and its relative re-tensioning should be
performed after no less than 30 minutes of motion necessary
for the normal adjustment of the belts. Best performance and
durability will be achieved with proper tensioning.
Note . In case of necessity or for routine maintenance, never
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replace a single belt but the complete set.
9.13 Transmission of power from the second PTO
Upon request, VFH series pumps can be supplied with an
auxiliary PTO on the opposite side to the drive (Transmission
of power from the second PTO).
Transmission can be carried out:
• By means of the V-belts.
• By means of the joint.
By means of the V-Belts, withdrawable Max Torque is:
65 Nm which corresponds to:
7 HP at 750 rpm;
7.4 HP at 800 rpm;
8.3 HP at 900 rpm;
9.3 HP at 1000 rpm;
11.1 HP at 1200 rpm.
By means of the joint, withdrawable Max Torque is:
130 Nm which corresponds to:
14 HP at 750 rpm;
14.8 HP at 800 rpm;
Fig. 12
16.6 HP at 900 rpm;
18.6 HP at 1000 rpm;
22.2 HP at 1200 rpm.
By means of the V-belt, the transmission is
considered suitable if: belt pull is applied at a max
distance of 22 mm from the bend shaft shoulder
(Fig. 14). Min diameter of pulley to be used =
Ø 100 mm
With transmission by means of the joint, pay
particular attention to perfect alignment so that no
transverse forces are generated on the pump shaft.
For applications differing from those specified
above, contact our Technical or Customer Service
Departments.
Fig. 13
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Fig. 14