Pumps - Kalmar DRF420-60S5 Maintenance Manual

page –
3
4
6
1. Hydraulic oil pump 1
2. Hydraulic oil pump 2
3. Hydraulic oil pump 3
4. Hydraulic oil pump 4
5. Brake oil pump
6. Pump cooling and filtering
10 Common hydraulics – 10.4 Pumps
10.4
Pumps, general
The machine's hydraulics are supplied from six pumps. Four of them
1
for the working hydraulics, one for cooling and filtering of the hy-
draulic oil and one for the brake system. The pumps are assembled
2
to 2 pump banks. Each pump bank consists of two axial piston
5 pumps with variable displacement, and a gear pump with fixed dis-
placement. The pump banks are mounted on the transmission's
power take-off.
The axial pistons pumps are connected mechanically and hydrauli-
cally in pairs and can be considered as one pump (hydraulic oil pump
unit). Non-return valves make sure that the pumps don't interfere
with each other.
The left hydraulic oil pump unit (position 1 and 2) supplies the control
valve for lift and extension, pump 2 also supplies the attachment's
control valve. At boom in, pump 1 and 2 are disconnected.
The right hydraulic oil pump unit (position 3 and 4) supplies the steer-
ing system and the control valve for lift and extension. The priority
valve ensures that there is always pressure to the steering system,
the remaining flow goes to the control valve for lift and extension.
The left fixed pump (position 5) supplies the brake system's brake
and cooling circuit across an accumulator charging valve, see sec-
tion 4 Brakes , group 4.3.1 Brake oil pump.
The right fixed pump (position 6) continuously circulates the hydrau-
lic oil through the cooler and hydraulic oil filter.
Maintenance manual DRF 400–450
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Pumps

7
UDRF01.04GB