Abstract
A qualitative discussion is given of the factors establishing the need for a compact electrohydraulic actuator to operate at a relatively low input-power level and capable of providing an output motion proportional to the magnitude of an electric input signal. The basic requirements of such an actuator are discussed, and then the design of each of its components including torque motor, valve, ram, and feedback mechanism, are described in detail. The results of a dynamic analysis of the complete system are employed to show how adequate system damping is provided, and to show how theoretical speed of response is obtained. The results of steady-state and dynamic tests are compared with the results of the analytical work. This actuator has been found to fulfill the needs of a number of instrumentation and control applications, and preliminary tests using compressed air instead of hydraulic oil indicate that pneumatic operation of such a device is also feasible.
