TSE DPT60, Руководство пользователя

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10
Series 90 Functional Description
Circuit Diagram showing Pressure
Control Mechanism
90000801E
Cross Section of Multi-Function Valve
90000806E
Pressure Limiter and High Pressure Relief Valves
Series 90 pumps are designed with a sequenced pres-
sure limiting system and high pressure relief valves.
When the preset pressure is reached, the pressure limiter
system acts to rapidly destroke the pump so as to limit the
system pressure. For unusually rapid load application,
the high pressure relief valve acts to immediately limit
system pressure by cross-porting system flow to the low
pressure side of the loop. The pressure limiter valve acts
as the pilot for the high pressure relief valve spool. The
high pressure relief valve is sequenced to operate at
approximately 35 bar (500 psi) above the level that ini-
tiates the pressure limiter valve.
Both the pressure limiter sensing valves and relief valves
are built into the multi-function valves (see above).
NOTE: For some applications, such as dual path ve-
hicles, the pressure limiter function may be de-
feated so that only the high pressure relief valve
function remains.
System Check Valves
The system check valves allow pressurized flow from the
charge pump to enter the low pressure side of the loop
whenever system pressure dips below a certain level.
This is needed as the pump will generally lose system
pressure due to leakage and other factors. Since the
pump can operate in either direction, two system check
valves are used to direct the charge supply into the low
pressure lines. The system check valves are poppet
valves located in the multi-function valve assembly.
Bypass Valves
The bypass valves ("tow") can be operated when it is
desired to move the vehicle or mechanical function when
the pump is not running. The valve is opened by manually
resetting the valve position.
The bypass valves are built into the multi-function valves.
Servo Pres.
Relief Valve
Charge Pressure
Relief Valve
Multi-Function Valve
Multi-Function Valve
To Control
Servo Piston
Servo Piston
Port "A"
Port "B"
Bypass
Adjustment
High Pressure
Relief / check
Valve Poppet
Pressure Limiter
Valve Poppet
Bypass
Actuator
Pressure Limiter
Adjustment Screw
Pressure Limiter
Lock Nut
Pressure Limiter Housing
Check Valve
Poppet
Bypass