General; Main Pressure; Cooler - Husqvarna DXR250 Operator's Manual

General

The task of the hydraulic system is to operate the machine's functions by means of hydraulic pressure and flow. The
system consists of hydraulic pump, tank, cooler, hydraulic motor, hydraulic cylinders, filters and valves of various kinds.
Hoses or pipes connect the components with each other.
Valves are used to control the hydraulic system's pressure, volume rate of flow and direction. Pressure control valves
limit or reduce the pressure to the value required. Volume control valves affect the hydraulic oil's flow and thereby the
speed of the functions. Direction control valves direct the hydraulic oil to the machine's different functions.
The hydraulic pump is of the variable displacement type and delivers a flow of DXR250, DXR270: 0-65 l/min (0-17 gal/
min) DXR300, DXR310: 0-75 l/min (0-20 gal/min).

Main pressure

The hydraulic system has different pressure levels.
Standard pressure, bar
Increased main pressure*, bar
Track tensioning and outriggers/dozer
blades up, 2,900 psi.
Hydraulic hammer, bar.
Pressure cut-off (Telescopic arm), bar
*Elevated main pressure is used only for the outriggers/dozer blades and when operating some tools.
If several functions are used at the same time the pressure will be set to lowest value.
If the oil temperature raises above 176 °F (80 °C) the hammer pressure will automatically be decreased to make the
machine able to run longer before it is overheated.

Cooler

The cooler has an integrated bypass valve that protects against overpressure in conjunction with, for example, cold start.
HYDRAULIC SYSTEM
DXR250
200
250
200
150 (19 kW)
-
DXR270 DXR300
200
250
200
150 (19 kW) 160 (22 kW)
-
DXR310
200 200
250 250
200 200
160 (22 kW)
- 180
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