Kärcher HD 1090 Service Handbook page 9

Unit function
Pump
1 suction valve
2 pressure valve
3 pressure gauge
4 oil reservoir
5 motor shaft
6 shaft seal
7 motor bearing
8 swash plate
9 piston glide shoe
10 piston spring
11 piston
12 oil seal
13 washer
14 low-pressure seal and support ring
15 bushing
16 washer
17 high-pressure seal
18 support ring
19 piston housing
20 O-ring
21 cylinder head
Function
The pump is a 3-piston swash plate pump with
drive running in an oil bath. It is directly attached
to the motor shaft, therewith achieving optimal
efficiency. When the piston returns, the water is
taken in via the open suction valve. The advan-
cing piston closes the suction valve and the
water is transported to the nozzle via the open
pressure valve.The operating pressure genera-
ted depends on the diameter of the nozzle bore.
7