Hyster D174, Руководство по обслуживанию и ремонту

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1900 SRM 97 Description
Description
Gear pumps have several sections and are made with
a single set (single stage) of gears or with multiple
sets (tandem) of gears. See Figure 1. A single-stage
pump has two covers and the gear housing with the
gears. Seals are used to prevent leaks between the
sections. Tandem pumps have a gear housing for
each set of gears. Most tandem pumps also have a
center section for the bearings. The inlet and outlet
ports are normally on the gear housing or rear cover.
The front cover has the seal for the input shaft. The
input shaft is connected to a driven sprocket, cou-
pling, or gear by splines or a key. All the gear pumps have devices that keep the
thrust clearance at a minimum when the pressure
increases. When the pressure is low, the clearance
increases to prevent wear. To prevent leakage when
the pressure is high, the oil from the outlet side
of the pump is transferred to a wear plate.
The
oil pushes the wear plate against the gears. Some
pumps have bearing blocks that move closer to the
gears when the pressure increases.
1. ONE-SECTION PUMP
2. DRIVE GEAR
3. TWO-SECTION PUMP
4. DRIVEN GEAR
Figure 1. Types of Gear Pumps
1