Figure 7–14. Servocylinder Functional Diagram

TM 1-1520-238-T-5 Change 1 7–31 7–7. SYSTEM DESCRIPTION (cont) 7–7 (d) The longitudinal, collective, lateral and directional servocylinders (fig. 7–14) are of tandem design and utilize primary and utility hydraulic system pressure. The servocylinder has two modes of operation, normal and BUCS (refer to TM 1-1520-238-T-7 for BUCS operation). During normal (mechanical input) operation, pressurized fluid from the utility hydraulic manifold enters the servocylinder through port P2. Fluid is routed through a one–way check valve to the stability augmentation actuator. The check valve prevents pressurized fluid from being forced back through the pressure port. The manual servo valve and stability augmentation actuator control both the primary and utility system fluids in the servocylinder. The position of the manual servo valve and stability augmentation actuator determines if fluid pressure is equalized or routed to the piston or primary barrel. When one side of the piston is pressurized, the other side is routed through return port R2 to the primary hydraulic reservoir. M68-110 ACTUATOR STABILITY AUGMENTATION RETURN UTILITY R2 PRESSURE UTILITY P2 POWER PISTON CHECK VALVE MANUAL VALVE UTILITY BARREL Figure 7–14. Servocylinder Functional Diagram