Fig. 6-1 Lifting System
1 ... fork 2, fork carriage 3, cargo-holding carriage 4 .. inner mast 5, outer mast
6.3 Inner & Outer Mast
The two-stage broad-vision mast consists of one stage of outer mast which can not lift and one
stage of inner mast which can stretch out and draw back vertically. The bottom of outer mast connects
with driving axle. The weight of the outer mast is mainly on the axle casing, the tilt cylinder bracket
outside of the middle part of outer mast connects the piston rod of tilt cylinder, which can realize the
forward and backward tilt of mast by operating multi-way valve. The both masts are welding parts,
they bear the vertical and horizontal load through rollers and side rollers, and make the mast move
stably.
6.4 Fork Carriage
The fork carriage installs four compound rollers and two main rollers, they make the fork
carriage stably move vertically through inner edge of inner mast groove, and bear both vertical and
horizontal load. Each side of fork carriage has 3 groups of rollers. When the forks lift up to the max.
height, the right and left pair of main rollers on the top will stretch out of upper edge of inner mast.
The forks hang on the carriage by hooks and lock in the beam groove of the fork carriage. The
distance between forks can be adjusted right or left by hand. Both forks ans fork carriage adopt
international stand (ISO) for general use and convient change.
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6.5 Adjustment of Lifting System
6.5.1 Make the mast stand vertically and descend completely. Adjust nuts at the bottom of train to
make fork carriage away from the ground for a distance of 2.
9
1-2.
99
in. guarantee the forks
descend to the ground.
6.5.2 Tilt the mast backward to adjust tensioning strength of lifting chain, and make the tensity of left
lifting chain and right lifting chain are equal.
6.5.3 Adjust "A" space between right and left screws of the
compound roller for 0.1 mrn-0.5mm. the roller on top
of outer mast can be adjusted by thin plate to keep "A"
space
6.5.4 Use thin plate to adjust "B" space to 0.lmrn-0.8mm
between guiding plate and inner mast column. The
thickness of washer is 0.5mm , I mm, which can be
optional according to needs.
6.5.5 The proper space between roller and groove steel wing edge is about 0.5mm-0.8mm. it can not
be adjusted. The roller shall be changed in case of too much abrasion
6.6 Failure diagnoisis & solutions
phenomenon
possible reason
solution
Tilting of fork
1. Tilt cylinder and seal ring are overworn.
Replace the piston seal or cylinder.
2. Control valve lever spring of multiway
carriage and mast
valve is out of order
change
Inflexible lifting,
I.
Cylinder
wall
is
stuck
by
piston
or
Change damaged parts
descending and
oiston rod is bent.
tilting of fork
2.
There
is
too
much fouling
in
the
clean
carriage
cylinder.
I. Fork
carriage assembly is improperly
Adjust the gap between channel rail
adiusted.
and side roller.
2. The gap between roller and mast channel
Adjust the roller gap.
Unsmooth lifting is not hie: enoucli.
and descending of
3. There is fouling between the moving
Remove foreign material
fork carriage
oarts.
4. Lubrication is insufficient.
Apply grease on the contact surface
of slide f!llide.
5. Inner mast tilts or fork carriae:e is bent.
Reoair or reolace.
118
Ranko R55 Forklift
Operator's Maintenance Manual
Common Faults & Solutions
Ranko R55 Forklift
Operator's Maintenance Manual
Common Faults & Solutions
