Hyster D174, Руководство по обслуживанию и ремонту

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Hydraulic Gear Pump Repair 1900 SRM 97
NOTE: THERE CAN BE A VARIATION OF INTERNAL PARTS ON DIFFERENT MODELS OF LIFT TRUCKS.
1. REAR COVER
2. SEAL GLAND
3. SEAL RETAINER
4. WEAR PLATE, REAR
5. DRIVEN GEAR
6. DRIVE GEAR
7. GEAR HOUSING
8. WEAR PLATE, FRONT
9. FRONT COVER
10. STUD
11. WASHER
12. NUT
13. SEAL
14. SNAP RING
15. SEAL
16. PIN
Figure 7. Hydraulic Gear Pump Single-Stage
NOTE: Some pump bodies will show gear marks
where the gears rotate because of the small clear-
ances between the parts. These gear marks do not
indicate a worn or damaged pump unless the pump
will not supply the volume and pressure shown in
the specifications.
3. Inspect gear housing for wear or grooves. Most
wear occurs on the inlet side of the gear cham-
ber. Put a straight edge across the inlet side of
the gear chamber. If a 0.13 mm (0.005 in.) thick-
ness gauge fits between the straight edge and
the housing, the gear housing must be replaced.
If the gear housing is worn, inspect bearings for
wear. If the system pressure is too high, the gear
housings will wear quickly. Grooves in the gear
chamber indicate dirt is in the oil. Small holes in
the outlet side of the gear chamber indicate that
cavitation has occurred. Make sure inlet hose,
fittings, and tank have no restrictions. Cavita-
tion can also occur when the engine speed is too
high.
If the surfaces of the gear chamber or gear teeth
have blue marks, the pump was too hot. Heat
damage in the pump can be caused by hot oil or
lack of oil. Check front seal surface to see if air
was entering the pump through the front seal.
Make sure the oil is the correct viscosity. The
wrong viscosity oil can increase leakage within
the pump. Leakage inside the pump increases
the oil temperature.
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