servoactuator

servoactuator

servoactuatorclick for a larger image
A variant of the standard actuator, incorporating a servovalve. The valve controls the jack and is operated by a linkage setup, so that the jack will follow the motion of the linkage. When the jack has reached the position set by the linkage, the servovalve will automatically close off the supply and the jack motion will stop. This type of actuator is common in powered flying controls.
References in periodicals archive ?
Consider the model of the general electric servoactuator:
Here [x.sub.1] is the output rotation angle; [x.sub.2] is the velocity at the motor output shaft; [x.sub.3] is the current through the servoactuator windings; [i.sub.p] is the reducing ratio of the reducer; [J.sub.H] is the moment of inertia of the electric servoactuator and of the rotating parts of the reducer; [K.sub.[omega]] and [K.sub.M] are the respective coefficients of the counter EMF and of the torque; [M.sub.d] describes the Coulomb friction at the motor; R and L are the active and inductive resistances of the electric servoactuator windings, respectively; [K.sub.U] is the amplification.
The top of the column is connected to a 500 kN electrohydraulic servoactuator through a holding device made of two steel plates and four long screw connectors.
The cyclic load was applied onto the top end of the column by the electrohydraulic servoactuator. Before applying the cyclic load, the axial pressure was applied onto the top end of the column by the hydraulic jack, and the axial pressure was maintained constant during the test.
A conventional hydraulic servoactuator can be idealized as demanding variable fluid flow at a constant working pressure.
In actuality, the supplied fluid arrives at the servoactuator at a somewhat reduced pressure, due to viscous flow losses in the hydraulic system tubing.
Experimental identification of some servovalve parameters used in an electro-hydraulic servoactuator development.
The Digital Adaptive Control System Design of a Hydraulic Servoactuator. Journal of Aeronautics, Astronautics and Aviation, Series A, Vol.42, No.3
Hydrulic bench for electro-hydraulic servoactuators and servo-valves testing.
Two servoactuators with integral position transducers are attached directly to the die ring to affect ovalization - effectively the rings can be pushed or pulled separately from either side during the shot.