Manitowoc Grove GRT9165, Руководство по обслуживанию

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HYDRAULIC SYSTEM GRT9165 SERVICE MANUAL
2-8 Published 10-01-2020 Control # 699-00
SUPPLY PRESSURE AND RETURN CIRCUIT
Description
The supply pressure and return circuit routes hydraulic oil
from the three hydraulic pumps to the directional control
valves for individual operating circuits. The supply pressure
and return circuit consists of the reservoir and integral filter,
three hydraulic pumps, a hydraulic oil cooler, and a 12-port
hydraulic swivel. Refer to Hydraulic Pumps in this section for
descriptions and maintenance instructions for each hydraulic
pump. Refer to
Swing System , page 6-1 for description and
maintenance instructions for the hydraulic swivel. Each
circuit description and components begin with the circuit
directional control valve.
Hydraulic Reservoir, Filter, and Temperature
Switches
The reservoir (Figure 2-1), attached to the right side of the
carrier frame has a total capacity of 838.58 L (221.5 gal),
with a full level of 729.5 L (192.6 gal).
The all-steel reservoir has an internally mounted full-flow
filter (Figure 2-2) and integral baffles that help cool the
hydraulic oil and prevent hydraulic oil foaming.
A tube located at the lower rear of the reservoir supplies oil to
the three hydraulic pumps. Return oil from the carrier
combination manifold bypasses the hydraulic cooler and
returns directly to the hydraulic oil filter in the top of the
reservoir. Return oil from all other functions is directed
through the hydraulic oil cooler and then to the hydraulic oil
filter. All return oil to the reservoir comes from the No. 1 dual-
port on the hydraulic swivel.
A temperature switch and thermistor are installed in the
lower rear of the hydraulic reservoir. The temperature switch
(190°F rising) (7, Figure 2-1) turns the hydraulic oil cooler fan
on and off as needed (see
Hydraulic Oil Cooler , page 2-12).
The thermistor (200°F rising) (6, Figure 2-1) will cause a
warning light in the cab to illuminate if the hydraulic oil
temperature is too high. The thermistor will also turn on the
oil cooling fan if the temperature switch fails.
NOTE: NOTE: Tightening torque for the thermistor is 44.7
±4.7 N-m (33 ±3.5 ft-lbs)
Tightening torque for the temperature switch is
10.9 ±2.7 N-m (8 ±2 ft-lbs)
A sight gauge is located on the front end of the reservoir to
indicate hydraulic oil level.
A filler neck and breather on top of the reservoir are for filling
and venting the reservoir. The filler neck includes a strainer
for catching contaminants and gaskets to prevent leaking.
The breather allows air to enter or exhaust from the
reservoir.The breather must be kept clean to prevent
damage to the reservoir. A breather guard protects the
breather and filler neck.
Two large round access covers on the top of the reservoir
provide access for cleaning. The covers are bolted to the top
of the reservoir and have gaskets to prevent leaking.
The hydraulic oil filter bolts to the top of the reservoir. The
filter housing contains a replaceable filter element. Returning
hydraulic oil flows through the filter head, filter element, and
into the reservoir (see
Hydraulic Oil Return Filter Assembly ,
page 2-10).
A gauge on the filter head indicates filter element restriction.
When back pressure caused by a dirty filter element exceeds
1.7 bar (25 psi), the bypass feature of the filter head allows
hydraulic oil to bypass the filter element and flow into the
reservoir through the bypass outlet.