General Pump SMH Operating instructions

SMH
Repair Manual
General Pump is a
member of the
Interpump Group Ref 300894 Rev. B
05-22

GENERAL PUMP A member of the Interpump Group SMH SERIES
Page 2
INDEX
1. INTRODUCTION ..................................................Page 3
2. REPAIR INSTRUCTIONS ...........................................Page 3
2.1 Repairing Mechanical Parts .......................................Page 3
2.1.1 Disassembly of Mechanical Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 4
2.1.2 Assembly of Mechanical Parts ..............................Page 15
2.1.3 Increase and Reduction Classes ............................Page 27
2.2 Repairing Hydraulic Parts ........................................Page 27
2.2.1 Dismantling the Head-Liners-Valves .........................Page 27
2.2.2 Assembling the Head-Liners-Valves .........................Page 31
2.2.3 Dismantling the Plunger Unit-Supports-Seals ..................Page 31
2.2.4 Assembling the Plunger Unit-Supports-Seals ..................Page 33
3. SCREW CALIBRATION ............................................Page 37
4. REPAIR TOOLS ..................................................Page 39
5. MAINTENANCE LOG ..............................................Page 40
Ref 300894 Rev. B
05-22

1. INTRODUCTION
This manual describes the instructions for Repairing SMH Series pumps, and must be carefully read and
understood before performing any repair intervention on the pump. Proper pump operation and longevity
depend on the correct use and maintenance. General Pump declines any responsibility for
damage caused by the misuse or the non-observance of the instructions described in this manual.
2. REPAIR INSTRUCTIONS
2.1 Repairing Mechanical Parts
Mechanical parts repair must be performed after removal of oil from the casing. To drain
the oil, remove the oil dipstick, (1, fig. 1) and then the draining plug (2, fig. 1).
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GENERAL PUMP A member of the Interpump Group SMH SERIES
The oil must be placed in a suitable container and disposed of in special centers.
It absolutely must not be discarded into the environment.
Read the contents of this manual carefully before each operation.
Danger Sign
Wear protective goggles.
Danger Sign
Put on protective gloves before each operation.
Ref 300894 Rev. B
05-22

Page 4
2.1.1 Disassembly of Mechanical Parts
The correct sequence is the following:
Completely empty the pump of oil, then disassemble the casing cover (and relative o-ring), unscrewing the (6)
M10 screws (1, fig. 2).
Remove the tab from the PTO shaft (1, fig. 3).
Unscrew the reduction gear cover fixing screws (1, fig. 4).
GENERAL PUMP A member of the Interpump Group SMH SERIES
Ref 300894 Rev. B
05-22

Page 5
Slowly screw in the 3 M8 screws (1. 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 Ø 120 (1, fig. 7).
Position the 3 grub screws or M8 threaded screws (1, fig. 5) with the function of extractors in the holes and
two sufficiently long M10 screws with the function of supporting the cover (2, fig. 5).
GENERAL PUMP A member of the Interpump Group SMH SERIES
Ref 300894 Rev. B
05-22

Page 6
Separate the pinion from the cover, working with an extractor hammer on the pinion itself (1, fig. 8)
Remove the Seeger ring Ø 55 (1, fig. 9) and the bearing support ring (1, fig. 10) from the pinion.
Extract the seal ring from the reduction gear cover, working from the inner side of the cover (1, fig. 11).
GENERAL PUMP A member of the Interpump Group SMH SERIES
Ref 300894 Rev. B
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Page 7
Remove the ring gear (1, fig. 14). Where necessary, it is possible to utilize an extractor hammer to be applied
on the (2) M8 holes (2, fig. 14).
Remove the tab from the shaft (1, fig. 15).
Unscrew the screws holding in the ring gear (1, fig. 12) and remove it (1, fig. 13).
GENERAL PUMP A member of the Interpump Group SMH SERIES
Ref 300894 Rev. B
05-22

Remove the ring gear support ring (1, fig. 16).
Remove the connecting rod caps with the lower semi-bearings, taking special care of the disassembly
sequence during disassembly.
The connecting 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 (1, fig. 18).
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Unscrew the connecting rod screws (1, fig. 17).
GENERAL PUMP A member of the Interpump Group SMH SERIES
Ref 300894 Rev. B
05-22

Unscrew the reduction gear box fixing screws (1, fig. 22).
Page 9
Advance the half supports completely in the direction of the hydraulic part to allow the crankshaft to come
out. To facilitate this operation, use special too part #F27566200 (1, fig. 19).
Remove the three upper half bearings of the half supports (1, fig. 20).
GENERAL PUMP A member of the Interpump Group SMH SERIES
Ref 300894 Rev. B
05-22

Page 10
Slowly screw in the 3 M8 screws (1, fig. 24) to prevent the box from tilting too far and getting locked in the
housing. Remove the box while supporting the crankshaft to prevent damage (1, fig. 25).
Unscrew the bearing cover fixing screws from the opposite side (1, fig. 27).
Position the 3 grub screws or M8 threaded screws (1, 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 (2, fig. 23).
GENERAL PUMP A member of the Interpump Group SMH SERIES
Ref 300894 Rev. B
05-22

Position the 3 grub screws or M8 threaded screws (1, fig. 28) with the function of extractors in the holes.
Remove the crankshaft casing from the PTO side (1, fig. 31).
Page 11
Slowly screw in the 3 M8 screws (1, fig. 29) to prevent the cover from tilting too far and getting locked in the
housing. Remove the bearing cover while supporting the shaft to prevent damage. (1. fig. 30).
GENERAL PUMP A member of the Interpump Group SMH SERIES
Ref 300894 Rev. B
05-22

In the event that it is necessary to replace one or more connecting rods or plunger guides, operate as follows:
unscrew the screws with tool part #F27566200 to unlock the connecting rods (1, fig. 32) and then extract the
connecting rod/plunger guide units from the back casing opening (1, fig. 33).
It is now possible to disassemble the plunger guide seal rings, taking care to not damage the plunger guide
sliding rod.
Whenever it becomes necessary to replace the plunger guide seal rings without
dismantling the entire mechanical part, it is possible to extract the seal rings with the
use of tool part #F27644300 operating as follows:
Insert the tool (1, fig. 34) and screw it on the rod to end stroke (1, fig. 35).
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GENERAL PUMP A member of the Interpump Group SMH SERIES
g. 34 g. 35
Ref 300894 Rev. B
05-22

Insert the pinion until the tool tooth enters completely into the oil seal (1, fig. 36). Continue rotating the pinion
until the oil seal is completely removed (1, fig. 36a)
Page 13
Remove the two spindle locking Seeger rings Ø 120 (1, fig. 37).
GENERAL PUMP A member of the Interpump Group SMH SERIES
g. 36 g. 36a
g. 36b
Remove the tool and remove the oil seal (1, fig. 36b).
Ref 300894 Rev. B
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Couple the half supports to the previously disassembled caps, referring to the numbering (1, fig. 40).
Page 14
To separate the rod from the plunger guide, unscrew the hexagonal head M6 screws with a wrench (1, fig.
41).
GENERAL PUMP A member of the Interpump Group SMH SERIES
Remove the spindle (1, fig. 38) and extract the connecting rod (1, fig. 39).
g. 41
Ref 300894 Rev. B
05-22

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 rod to the plunger guide. Insert the plunger guide rod into its seat on the plunger guide (1, fig.
42) and fix the rod to the plunger guide using the 4 M6x20 screws (1, fig. 43).
Page 15
Lock the plunger guide in a vice with the aid of a special tool and calibrate the screws with a torque wrench
(1, fig. 44) as indicated in chapter 3 “Screw Tightening Calibration”.
Insert the connecting rod in the plunger guide (1, fig. 39) and then insert the spindle (1, fig. 38). Apply the two
shoulder Seeger rings (1, fig. 37).
Assembly has been carried out properly if the connecting rod foot, plunger guide
and spindle rotate freely.
Separate the caps from the half supports. Proper coupling can be verified by the numbering on the side
(1, fig. 40). After having checked casing cleaning, proceed with assembly of half support/plunger guide unit
inside casing rods (1, fig. 33).
Insertion of the half support/plunger guide unit in the casing must be made with the half
bearings set in the direction in which numbers are visible from above.
GENERAL PUMP A member of the Interpump Group SMH SERIES
g. 42 g. 43
g. 44
Ref 300894 Rev. B
05-22

The crankshaft must always be assembled with the PTO on the opposite side with respect to
the 1/2” holes for the oil discharge plugs on the pump casing (1, fig. 51).
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Insert the shaft from the PTO side, taking care not to hit the previously assembled connecting rod shanks
(1, fig. 48) and (1, fig. 49).
Block the three units with the use of special tool part #F27566200 (1, fig. 32)
Pre-assemble the ring inside the crankshaft bearings (on both sides of the shaft down to the stroke) using
special tool part #F27604700 (1, fig. 46) (1, fig. 47).
The inner and outer rings of the bearings must be reassembled keeping the same
coupling with which they were disassembled.
GENERAL PUMP A member of the Interpump Group SMH SERIES
Ref 300894 Rev. B
05-22

Fully insert the shaft in the casing (1, fig. 50 and fig. 51).
Page 17
Pre-assemble the outer ring of the pinion bearing on the reduction gear with the aid of special tool part
#F27604900 (1, fig. 52), inserting fully down to end stroke (1, fig. 53).
From the opposite side of the reduction gear box, pre-assemble the external ring of the crankshaft bearing
with the use of tool part #F27605000 (1, fig. 54), inserting fully down to end stroke (1, fig. 55).
GENERAL PUMP A member of the Interpump Group SMH SERIES
Ref 300894 Rev. B
05-22

Assemble the bearing cover (and related seal) using an extractor hammer (1, fig. 60).
Position the bearing cover in such a way that the “Pratissoli” logo is perfectly
horizontal.
Repeat this operation on the bearing box, preassembling the external crankshaft bearing ring with the help of
special tool part #F27605000 (1, fig. 56), inserting fully down to end stroke (1, fig. 57).
Page 18
Insert the side seal on the bearing cover (1, fig. 58) and lift the crankshaft to favor cover insertion (1, fig. 59).
GENERAL PUMP A member of the Interpump Group SMH SERIES
Ref 300894 Rev. B
05-22

Tighten the (8) M10x30 screws (1, fig. 61). Calibrate the screws with a torque wrench as indicated in Section
3 “Screw Tightening Calibration”.
Page 19
From the opposite side, insert the side seal on the reduction gear box (1, fig. 62) and lift the crankshaft to
favor cover insertion (1, fig. 63).
Assemble the reduction gear box (and related seal) using an extractor hammer (1. fig. 64).
GENERAL PUMP A member of the Interpump Group SMH SERIES
Ref 300894 Rev. B
05-22

Remove the tool for blocking the connecting rods tool part #F27566200 (1, fig. 32)
Insert the upper half-bearings between the connecting rods and the shaft (1, 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 (1, fig. 67).
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Tighten the (8) M10x40 screws (1, fig. 65). Calibrate the screws with a torque wrench as indicated in Section
3, “Screw Tightening Calibration”.
Apply the lower half-bearings to the caps (1, fig. 68) ensuring that the half-bearing reference notches are
positioned in their housing on the cap (1, fig. 68).
Fasten the caps to the half supports by means of M10x1.5x80 screws (1, 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 Section 3 “Screw Tightening Calibration”, bringing
the screws to tightening torque at the same time.
GENERAL PUMP A member of the Interpump Group SMH SERIES
Ref 300894 Rev. B
05-22