HPU400 Hydraulic Power Units
Kobelt Manufacturing Co. Ltd.
Rev A
MNL_HPU400
18 of 33
5
O
PERATION
The HPU operates as follows:
•
Manifold receives oil from pump, and outputs to steering lines. Output flow determining
the speed of the rudder.
•
Output flow is controlled by flow control valves.
•
Pressure relief valve is factory set to approximately 750 psi.
•
Excess flow is returned to tank via differential bypass valve.
•
pilot operated check valves allow free flow from the inlet port to outlet. Inlet pressure
open the opposite side check valve and allows flow comeback. When there is no
pressure in lines (directional valve is in center) both check valves are close and holding
the load in position.
•
By energizing related solenoid on directional valve, flow will be sent to port or
starboard.
•
Hydraulic in-line filter provides protection for small, high pressure systems up to 3,000
PSI. By using this filter at the pressure side of a pump, foreign particles 90 microns and
larger, such as those created by pump wear, are removed before damage can result to
the valving in the system. A sintered bronze element ensures protection against
crushing should dirt accumulate and increase pressure drop across the element.
