Servo valves are part of the Honeywell family of Electro Mechanical Interface Devices (EMIDs) which includes the electro-hydraulic servo valve (EHSV), fueldraulic servo valve, torque motor, pneumatic torque motor as well as solenoids.
EMIDs convert electric signals into mechanical power by manipulating fluid flow. Honeywell EMIDS help operate complex equipment remotely.
An electro-hydraulic servo valve (EHSV) is a device that uses an electrical input signal to control flow of a gas or liquid. The flow of this medium is then used to drive the opening or closing of a valve or movement of an actuator.
The EHSV thus provides an efficient and reliable way to control fluid flow and mechanical motion in various locations on aircraft or engines.
A typical EHSV made by Honeywell consists of two stages. The first stage is a torque motor that uses the electrical input signal to develop an electro-magnetic force that moves an armature to control the flow of fluid, such as pressurized fuel. The second stage is a hydraulic amplifier that uses the relatively small flows from the torque motor to actuate a valve that can provide very large flows.
The torque motor can also be used by itself (a single stage electro-hydraulic valve) when lower flows are sufficient.
EHSVs also have numerous applications outside of the aerospace industry; however, aviation applications are more demanding in terms of safety, reliability and harsh operating environments.
Having mastered critical elements of EHSV manufacturing, including precision manufacturing and assembly, prevention of leakage and control of contamination, Honeywell holds a leading position by offering compact, lightweight, and highly durable EHSVs.