M+S MH 2 Series User manual

SERVICE MANUAL
Hydraulic Motors type MH-series 2
and MLHH…B
2008

Service Manual
Hydraulic Motor type MH-series 2,
MLHH…B
- 2 -

Service Manual
Disassembly
Hydraulic Motor type MH-series 2,
MLHH…B
- 3 -
Instructions in this manual are for MH-series
2 and MLHH…B motors.
Cleanliness is extremely important when
repairing these motors. Work in clean area!
Before disassembly, drain oil from motor.
Remove castellated nut, washer and key
when used. For motors with drain unscrew drain
plug and remove washer (O-ring).
Although not all drawings show the motor in
disassembly devise (vice), we recommend that
you keep motor clamped during disassembly.
1. Place the motor in disassembly devise with
output shaft down.
Fig.1
2. Unscrew screws using S17 socket spanner.
Remove washers (see Figure 1).
3. Remove end cover.
Fig.2
4. Remove the roll-gerotor set carefully to
prevent dropping of rollers and rotor from stator.
Do not dismount!
Remove O-rings from roll-gerotor set
grooves (see Figure 2).
Fig.3
5. Remove cardan shaft (see Figure 3).
6. Remove distributor plate.
7. Remove O-ring from housing.
Reposition motor in disassembly devise with
shaft upwards.
Fig.4
8. Unscrew screws M5 using S5 Allen head
spanner (see Figure 4).
9. Remove flange from housing. Dust seal
and Shaft seal will come out with flange.
Fig.5

Service Manual
Disassembly
Hydraulic Motor type MH-series 2,
MLHH…B
- 4 -
10. Remove with screwdriver Dust seal and
Shaft seal from flange (see Figure 5). Work from
outer side for both seals.
11. Remove shaft from housing.
Fig.6
12. Remove thrust washer and needle bearing
from shaft (see Fig.6).
13. Remove O-ring from outer diameter of
thrust washer.
Seal Kits:
SK41 5129 6180 for MH…series 2
SK41 5129 6190 for MH…U series 2
SK41 5128 9700 for MLHH…B
SK41 5128 9705 for MLHH…U B
1. CLEANING:
Wash all parts (except seals) in a weak
solvent on carbon base and then degrease.
2. MEASURING AND REPLACEMENT:
Measure all parts and compare actual
dimensions with the nominal ones given in the
technical documentation. Replace any parts
with scratches or burrs that could cause leakage
or damage with new ones. Use new seals when
reassembling motor.
3. LUBRICATION:
Lubricate all parts which should be
reassembled with light film of petroleum jelly.

Service Manual
Reassembly
Hydraulic Motor type MH-series 2,
MLHH…B
- 5 -
1. Lubricate output shaft with hydraulic oil
(see Fig.6).
Fig.7
2. On the bottom of the shaft mark a Timing
dot placed between forward and backward
valving slots as shown on Figure 7.
3. Lubricate lightly all internal housing
surfaces with hydraulic oil. Mount shaft in
housing.
4. Place the motor in reassembly device with
output shaft up.
5. Install needle bearing, then thrust washer
on the shaft.
6. Place O-ring 53,00х2,00 round thrust
washer.
Fig.8
7. Place flange on clean soft surface.
Lubricate shaft seal and dust seal with light film
of clean petroleum jelly (Shell Retinax Grease
HDX2).
8. Place shaft seal in Flange and firmly push
with Seal driver (see Fig.8).
9. Install dust seal in flange. Carefully press
dust seal into place.
Lips of shaft seal and dust seal must face
outward.
Important: Check seal condition after
installing in housing. If damaged, cut or
improperly installed, replace with new ones.
10. Install the spigot flange incl. assembled
seals on shaft. Prevent the seals against damages.
11. Install 6 screws and alternately torque
them to 10÷12 Nm.
12. Reposition motor in reassembly devise
with shaft down.
13. Lubricate and install O-ring in housing
seal groove (see Fig.3).
14. Install cardan shaft into splines of output
shaft. Mark one cardan shaft tooth and align this
tooth with timing dot on shaft.
Timing Procedure
Standard rotation:
15. Align shaft timing dot with any housing
bolt hole.
Fig.9

Service Manual
Reassembly
Hydraulic Motor type MH-series 2,
MLHH…B
- 6 -
16. Install distributor plate on housing.
Remember which bolt hole was aligned with the
shaft timing dot.
17. Lubricate O-rings (2 pcs.) and place
them in seal grooves of both stator sides. (see
Fig.2).
18. Place roll-gerotor set on spacer plate
positioning any star point over the bolt hole
aligned with the timing dot. Stepped bolt holes
are facing with smallest diameter to the
distributor plate (see Fig 9).
19. Rotate roll-gerotor set to line up with bolt
holes.
Reverse Rotation:
Reverse rotation is obtained by positioning
any star valley over the aligned bolt hole (see
Fig 9A).
Fig.9А
20. Carefully place end cover on roll-gerotor
set (see Fig.1).
Fig.10
21. Install screws and washers in end cover.
Tighten screws with 6 ÷ 6,5 daNm torque using
an S=17 mm spanner socket in sequence as shown
in Fig.10.
22. Install washer (O-ring for MLHH...4,5) on
drain plug. Tighten plug with hex key S6 with
torque 2,0 ÷ 2,5 daNm.
23. Install key in shaft key groove. For cone
shafts install washer and screw castellated nut.