ELECTROHYDRAULIC SERVO DRIVE Russian patent published in 2006 - IPC F15B9/00 

FIELD: fluid-pressure actuators.

SUBSTANCE: electrohydraulic servo drive comprises electric motor and controllable axial-plunger pump with shaft and rotatable double-arm cage spring-loaded from one of the ends and cooperating with the second end by the plunger-controller, compensating-pressing device with tank and control chamber, hydraulic motor, make-up valve, power limiter, reduction valve, and two-cascade electrohydraulic amplifier with the controllable throttle mounted in the first cascade and spring-loaded slide valve in the second cascade connected with the planes of the hydraulic motor. The slide valve of the electrohydraulic amplifier is connected with the plunger-controller through the two-collar slide valve spring-loaded from both of the sides whose chambers are connected with the nozzles of the first cascade and chambers of the slide valve of the second cascade whose control hydraulic lines are connected with the spaces of the hydraulic motor. The space between the collars is connected with the first space of the plunger-controller connected with the pressure hydraulic line of the pump through the second space and spring-loaded with one of the collars defined by a groove made in the middle of the plunger-controller.

EFFECT: enhanced reliability.

2 dwg