Mec 34-J Diesel, Руководство по обслуживанию и запасным частям, Страница: 25 / 272

Page 19 34-J Desel - Servce & Parts Manual
December 2021 Secton 10 - Hydraulc System
Hydraulic Roadmap
Hydraulic Reservoir
Hydraulic fluid is held in the reservoir for delivery to the pumps and is returned to the reservoir
after use. Returning hydraulic fluid is routed through a filter before entering the reservoir. The
reservoir also serves as the oil cooling device.
Drive Pump
The closed-loop hydrostatic piston-type Drive Pump with infinitely variable proportional control
delivers hydraulic fluid under pressure to the Wheel Motors.
Functions Pump
The gear-type Functions Pump delivers hydraulic fluid under pressure to the Functions Manifold
and provides pressure to the platform and turntable functions, in addition to controlling the axle
cylinders and the brakes.
Functions Manifold
The Functions Manifold directs the hydraulic fluid to the Boom Lift, Boom Extend and
Steering Cylinders, as well as fluid flow to the Platform Functions Manifold, through the use of
electronically-operated solenoid valves.
Platform Functions Manifold
The Auxiliary Manifold provides hydraulic control to the Platform Level, Platform Rotate and Jib
functions.
Wheel Motors/brake Hubs
There are four hydraulic wheel motors to provide power to all four wheels. The wheel motors
turn planetary hubs with integral spring-applied, hydraulically-released brakes. The brakes
are released by hydraulic pressure from the Main Manifold. The drive system is hydrostatic;
deceleration is provided by the drive motor.
Axle Cylinders
Two hydraulic cylinders control angle of steering axle relative to the frame. The axle cylinders
move freely and allow the axle to float when driving over rough terrain when the platform is
stowed. When platform is elevated, the axle cylinders lock in place to increase machine stability.
Each cylinder has an integral solenoid valve for load-holding.
Steer Cylinders
This machine has two Steer Cylinders that control the angle of the steerable wheels.
Steering is not self-centering.
Boom Lift Cylinder
One hydraulic lift cylinder raises and lower the boom assembly.
Boom Extend Cylinder
One hydraulic cylinder extends and retracts the upper boom.
Platform Level Cylinder
One hydraulic cylinder levels the platform as needed as the boom is raised and lowered.
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