Moog D633-A Series, Руководство пользователя

Страница: 24 / 88

3 Product Description Hydraulics
© Moog GmbH User Manual "D633-A Series" (CA80942-001; Version 1.0, 12/08) 16
3.3 Hydraulics
3.3.1 Open-loop flow control (Q-control)
Operational mode:
Open-loop flow control
(Q-control)
The valves are operated as open-loop flow control valves.
In open-loop flow control an open-loop control of the spool position is carried
out. The predefined command signal corresponds to a particular spool position.
The flow that is set depends not only on the spool position but also on the pres-
sure difference
∆
p at the individual control lands.
Ö Chapter "5.1 Dependency of Flow and Pressure Drop", page 29
Ö Chapter "5.2 Flow signal characteristic curve", page 29
3.3.2 Valve configurations and hydraulic symbols
Valve configurations
Depending on the model, the following valve configurations are possible:
• 2-way operation
Ö Chapter "3.3.2.2 2-way and 2x2-way operation", page 17
• 3-way operation
Ö Chapter "3.3.2.1 4-way and 3-way operation", page 16
• 4-way operation
Ö Chapter "3.3.2.1 4-way and 3-way operation", page 16
• 2x2-way operation
Ö Chapter "3.3.2.2 2-way and 2x2-way operation", page 17
3.3.2.1 4-way and 3-way operation
4-way and 3-way
operation
With 4-way operation the valves can be used to control the flow in ports A
and B (used as throttle valves).
Port A or B must be blocked in order to obtain 3-way operation.
Leakage port Y must be used if the pressure in tank port T exceeds a value of
50 bar (725 psi).
Ö Chapter "3.3.3 Leakage port Y", page 17
The valves are available with zero lap, less than ±3 % or ±10 % positive over-
lap.
Hydraulic symbols: 4-way
and 3-way operation
Ö Chapter "3.2.1.1 Valves with fail-safe function F, D or M", page 14
WARNING To ensure faultless valve operation, it is necessary to con-
figure the valve correctly with regard to flow and pressure.
Figure 3: 4-way operation with mechanical
fail-safe function F (hydraulic symbol)
Figure 4: 3-way operation with mechanical
fail-safe function F (hydraulic symbol)