Pratissoli MW Series Operating instructions

MW
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MW Series
Repair
manual
MW45 – MW50 – MW55
MW32 – MW36 – MW40
Menu

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INDEX
1. INTRODUCTION 3
2. REPAIR GUIDELINES 3
2.1 Repairing mechanical parts.................................................................................................3
2.1.1 Disassembly of mechanical parts........................................................................4
2.1.2 Assembly of mechanical parts..........................................................................15
2.1.3 Increase and reduction classes..........................................................................27
2.2 Repairing hydraulic parts..................................................................................................27
2.2.1 Dismantling the MW32 MW36 MW40 head – valve units..............................27
2.2.1 Dismantling the MW32 MW36 MW40 – valve units......................................31
2.2.3 Dismantling the MW45 MW50 MW55 head – valve units..............................37
2.2.4 Assembling the MW45 MW50 MW55 head – valve units...............................40
2.2.5 Dismantling the piston unit – supports – seals...............................................45
2.2.6 Dismantling the piston unit – supports – seals...............................................48
3. SCREW TIGHTENING CALIBRATION 52
4. REPAIR TOOLS 53

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1. INTRODUCTION
This manual describes the instructions for repair of the MW pump family and should be carefully read and
understood before any intervention on the pump.
Proper pump operation and duration depend on the correct use and maintenance.
Interpump Group disclaims any responsibility for damage caused by negligence or failure to observe
with the standards described in this manual.
2. REPAIR GUIDELINES
2.1 Repairing mechanical parts
Mechanical parts repair must be performed after removal of oil from the casing.
To take out the oil, remove the oil dipstick pos.c, fig. 1 and then the discharge plug pos.d, fig.1
The oil must be placed in a suitable container and disposed of in special centres.
It absolutely should not be discarded into the environment.
fig. 1

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2.1.1 Disassembly of mechanical parts
The proper sequence is as follows:
Fully empty the oil from the pump, then disassemble the casing cover (and relative O-ring), unscrewing the 6
M10 screws (pos.c, fig.2).
Remove the tab from the PTO shaft (pos.c, fig.3).
Unscrew the reduction gear cover fixing screws (pos.c, fig.4).
1
fig. 3
1
fig. 2
fig. 4
1

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Position the 3 grub screws or M8 threaded screws (pos.c, fig.5) with the function of extractors in the holes
and two sufficiently long M10 screws with the function of supporting the cover (pos.d, fig.5).
Slowly screw in the 3 M8 screws (pos.c, fig.6) with the function of extractors to fully remove the cover unit
and pinion
Complete disassembly of the reduction gear cover from the pinion is possible following these steps:
Remove the Seeger ring Ø120 (pos.c, fig.7)
fig. 5
1
2
fig. 6
1
fig. 7
1
2
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Separate the pinion from the cover, working with an extractor hammer on the pinion itself (pos.c, fig.8)
Remove the Seeger ring Ø55 (pos.c, fig.9) and the bearing support ring (pos.c, fig.10) from the pinion
Extract the seal ring from the reduction gear cover, working from the inner side of the cover (pos.c, fig.11).
fig. 8
1
fig. 9
1
fig. 10
1
fig. 11
1

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Unscrew the screws holding in the ring gear (pos.c, fig.12) and remove it (pos.c, fig.13).
Remove the ring gear (pos.c, fig.14). Where necessary, it is possible to utilise an extractor hammer to be
applied on the 2 M8 holes (pos.d, fig.14)
Remove the tab from the shaft (pos.c, fig.15).
fig. 12
1 fig. 13
1
1
2 fig. 14
fig. 15
1

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Remove the ring gear support ring (pos.c, fig.16).
Unscrew the con-rod screws (pos.c, fig.17).
Remove the con-rod caps with the lower semi-bearings, taking special care of the disassembly sequence
during disassembly.
The con-rod caps and their relative half supports must be reassembled in exactly the same
order and coupling with which they were disassembled.
To avoid possible errors, caps and half supports have been numbered on one side (pos.c, fig. 18) .
1
fig. 17
fig. 18
1
fig. 16
1

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Advance the half supports completely in the direction of the hydraulic part to allow the bend shaft to come
out. To facilitate this operation, use special tool (code 27566200), (pos.c, fig.19).
Remove the three upper half-bearings of the half supports (pos.c, fig.20).
Unscrew the reduction gear box fixing screws (pos.c, fig.21 and fig.22).
fig. 19 1
fig. 20
1
fig. 21
1
fig. 22

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Position the 3 grub screws or M8 threaded screws (pos.c, fig.23) with the function of extractors in the holes
and two sufficiently long M10 screws with the function of supporting the reduction gear box (pos.d, fig.23).
Slowly screw in the 3 M8 screws (pos.c, fig.24) to prevent that the box can tilt too far and get locked in the
housing.
Remove the box while supporting the shaft to prevent damage (pos.c, fig.25).
Unscrew the bearing cover fixing screws from the opposite side (pos.c, fig.26 and fig.27).
fig. 23
1
2
fig. 24
1
1
fig. 26
1
2
fig. 25
fig. 27
1

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Position the 3 grub screws or M8 threaded screws (pos.c, fig.28) with the function of extractors in the holes
Slowly screw in the 3 M8 screws (pos.c, fig.29) to prevent that the cover can tilt too far and get locked in the
housing.
Remove the bearing cover while supporting the shaft to prevent damage (pos.c, fig.30).
Remove the bend shaft casing from the PTO side (pos.c, fig.31).
fig. 31
1
fig. 28
1
fig. 29
1
fig. 30
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In the event that it is necessary to replace one or more con-rods or piston guides, operate as follows:
Unscrew the screws with tool code 27566200 to unlock the con-rods (pos.c, fig.32) and then extract the
con-rod-piston guide units from the back casing opening (pos.c, fig.33).
It is now possible to disassemble the piston guide seal rings, taking care to not damage the piston guide
sliding rod.
Whenever it becomes necessary to replace the piston guide seal rings without
dismantling the entire mechanical part, it is possible to extract the seal rings with the use of
tool code 27918500 operating as follows:
Insert the tool between the rod and the seal ring (pos.c, fig.34) and, with the extractor hammer, complete
insertion of the tapered section inside the seal ring (pos.c, fig.35)
1
fig. 32 fig. 33
1
fig. 34
1
fig. 35
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Extract the seal ring using the tool extractor hammer (pos.c, fig.36).
Remove the two spindle locking Seeger rings Ø120 (pos.c, fig.37).
Remove the spindle (pos.c, fig.38) and extract the con-rod (pos.c, fig.39)
fig. 37
1
fig. 38
1
fig. 39
1
fig. 36
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Couple the half supports to the previously disassembled caps, referring to the numbering (pos.c, fig.40).
To separate the rod from the piston guide, unscrew the hexagonal head M10 screws with a 17 socket
wrench (pos.c, fig.41), blocking the rod with the 36 fork spanner.
fig. 41
1
1 fig. 40

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2.1.2 Assembly of mechanical parts
Proceed with assembly following the reverse order indicated in point 2.1.1.
The proper sequence is as follows:
Assemble the red to the piston guide.
Insert the elastic pin Ø5 in its hole on the piston guide (pos.c, fig.42) and join the rod to the piston guide by
means of M10x35 screws (pos.c, fig.43).
Lock in the rod in correspondence with the two planes with a 36 fork spanner (pos.c, fig.44) and proceed
with calibration with a torque wrench (pos.c, fig.45) as indicated in paragraph 3 “Screw tightening
calibration”.
Insert the con-rod in the piston guide (pos.c, fig.39) and then insert the spindle (pos.c, fig.38). Apply the
two shoulder Seeger rings (pos.c, fig.37).
Assembly has been carried out properly if the con-rod foot, piston guide and spindle rotate
freely
Separate the caps from the half supports. Proper coupling can be verified by the numbering on the side
(pos.c, fig.40).
After having checked casing cleaning, proceed with assembly of half support-piston guide unit inside casing
rods (pos.c, fig.33).
Insertion of the half support-piston guide unit in the casing must be made with the
half bearings set in the direction in which numbers are visible from above
fig. 42
1
fig. 43
1
1
fig. 44 fig. 45
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Block the three units with the use of special tool code 27566200 (pos.c, fig.32).
Pre-assemble the ring inside the bend shaft bearings (on both sides of the shaft down to the stroke) using
special tool code 27604700 (pos.c, fig.46) (pos.c, fig.47).
The inner and outer rings of the bearings must be reassembled keeping the same
coupling with which they were disassembled
Insert the shaft from the PTO side, taking care not to hit the previously assembled con-rod shanks (pos.c,
fig.48) and (pos.c, fig.49).
The bend shaft must always be assembled with the PTO on the opposite side
with respect to the G1/2" holes for the oil discharge plugs on the pump casing (pos.d,
fig.51).
fig. 46
1
fig. 47
fig. 49
1
fig. 48
1
1

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Fully insert the shaft in the casing (pos.c, fig.50 and fig.51)
Pre-assemble the outer ring of the pinion bearing on the reduction gear with the aid of special tool code
27604900 (pos.c, fig.52), inserting fully down to end stroke (pos.c, fig.53)
From the opposite side of the reduction gear box, pre-assemble the external ring of the bend shaft bearing
with the use tool code 27605000 (pos.c, fig.54), inserting fully down to end stroke (pos.c, fig.55)
fig. 50 fig. 51
1 1
2
fig. 52 fig. 53
1
1
fig. 54 fig. 55
1
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Repeat this operation on the bearing box, pre-assembling the external bend shaft bearing ring with the help
of special tool code 27605000 (pos.c, fig.56), inserting fully down to end stroke (pos.c, fig.57)
Insert the side seal on the bearing cover (pos.c, fig.58) and lift the bend shaft to favour cover insertion
(pos.c, fig.59).
Assemble the bearing cover (and relative seal) using an extractor hammer (pos.c, fig.60)
Position the bearing cover in such a way that the "Pratissoli" logo is perfectly horizontal
fig. 58
1
fig. 59
1
fig. 56 fig. 57
1
1
fig. 60
1

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Tighten the 8 M10x30 screws (pos.c, fig.61).
Calibrate the screws with a torque wrench as indicated in paragraph 3 “Screw tightening calibration”.
From the opposite side, insert the side seal on the reduction gear box (pos.c, fig.62) and lift the bend shaft
to favour cover insertion (pos.c, fig.63).
Assemble the reduction gear box (and relative seal) using an extractor hammer (pos.c, fig.64)
fig. 62
1
fig. 63
1
fig. 61
1
fig. 64
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Tighten the 8 M10x40 screws (pos.c, fig.56).
Calibrate the screws with a torque wrench as indicated in paragraph 3 “Screw tightening calibration”.
Remove the tool for blocking the con-rods code 27566200 (pos.c, fig.32).
Insert the upper half-bearings between the con-rods and the shaft (pos.c, fig.66).
For proper assembly of the half-bearings, ensure that the reference tab on the
half-bearings are positioned in their housing on the half support (pos.c,fig.67).
Apply the lower half-bearings to the caps(pos.c, fig.68) ensuring that the half-bearing reference notches are
positioned in their housing on the cap (pos.d, fig.68).
Fasten the caps to the half supports by means of M10x1.5x80 screws (pos.c, fig.69).
Note the correct assembly direction of the caps. Numbering must be
turned upward.
Calibrate the screws with a torque wrench as indicated in paragraph 3 “Screw tightening calibration”,
bringing the screws to tightening torque at the same time.
fig. 66
1
fig. 67
1
fig. 65
1