Category: Woodward

Features

The actuator output is an ISO 9409 flange. This allows for easy mounting of levers to

simplify replacement. The orientation of the output flange relative to the bracket base

is the same for each actuator. Additionally, the actuators are equipped with break-away

stops that prevent the actuator from exceeding the maximum output travel range

during setup. An output position indicator is standard.

The EM-80 and EM-300 systems include a mounting bracket with hole pattern. The

bracket design ensures that stresses in the actuator are reduced to a minimum.

Actuator specifications and performance are based on a system including bracket.

The actuators are equipped with a flying-lead position-sensor cable (including connector).

A position sensor cable connecting the actuator and the driver is available.

This cable is similar for both the EM-80 and the EM-300.

A single EM-driver is used for both the EM-80 and the EM-300. Only the software

setup for each actuator system differs. Monitoring, alarm, and diagnostics are available.

An EMI power filter is supplied to suppress emissions.

Optional Features

The EM-80 and EM-300 systems include a bracket for mounting on the engine or turbine.

A standard mounting hole pattern is provided. Alternative patterns are available on request.

Applications

The EM-80 and EM-300 are intended to be mounted on large diesel, gas, and

gasoline engines, and on all types of turbines, to control the position of engine fuel

racks, turbine fuel valves, turbine and turbocharger variable geometry, and to handle

timing control. These systems are well suited for engines without a mechanical drive

or hydraulic oil supply.

Description

The EM-80 and EM-300 are all-electric actuator systems that provide 40 degrees of

actuator output rotation. Each system consists of a three-phase brushless ac motor

which drives a high-precision planetary reduction gear box. A dedicated driver

controls the actuator position and allows monitoring of most features.

PC/Windows based software facilitates the system setup. The EM-80 and EM-300

are freely programmable to meet many customer requirements.

 Fast slew times

 Freely programmable

 Brushless servomotor and resolver

 Precision gearbox, high stiffness, low backlash

 CE marking

 Models with ABS, BV, and DNV certification

 Cost effective solution

The EM-80 and EM-300 actuators have different position-sensing systems. Both

systems use the same hollow shaft resolver, producing a sine and cosine wave

output with an overall accuracy of 12 arc-minutes. This resolver is mounted at the

rear of the motor and looks at the relative position of the motor shaft.

The EM-80 uses only the resolver since the 1:7 gear ratio within the gearbox

allows full stroke of the actuator output flange with less than one full revolution of

the motor shaft.

The EM-300 has a 1:20 gearbox ratio to achieve the required torque output.

Because of this, the motor shaft rotates more than one full revolution to achieve

full stroke. To ensure proper position indication over the full range, a 10-turn

potentiometer is added behind the resolver to supply a coarse position signal

from which the correct rotor revolution is deduced. The same resolver as used on

the EM-80 gives the accurate position within that revolution.

EM-80/-300 System Description

The EM-80/-300 system consists of an actuator, a driver, an AC line filter

(required for marine TN/TT only), and interconnection cables.

The EM-80 and EM-300 are all-electric actuator systems that provide a nominal

40° of actuator output rotation. Each system consists of a three-phase brushless

ac motor which drives a high-precision planetary reduction gear box. A dedicated

driver controls the actuator position.

Actuator

The actuator is available in two versions, offering two work output levels, EM-80

and EM-300. Both versions use the same three-phase brushless AC motor.

The difference in output is achieved by the use of two different gearboxes. The

EM-80 uses a single-stage planetary 1:7 gear ratio, while the EM-300 uses a

two-stage planetary 1:20 gear ratio.

The motor–gearbox combination comes assembled on a mounting bracket with a

fixed hole pattern. Although the EM-300 is longer than the EM-80. both use the

same mounting hole pattern, allowing the actuators to be interchangeable.

The output flange provides an easy mounting surface for a variety of lever

configurations, and is equipped with a rugged pointer and scale for quick output

position reference while working on the prime mover. A breakaway extension and

two stop pins form a simple means of detecting whether the actuator has been

driven outside its operating boundaries.

Introduction

This manual covers components of the EM-80/-300 Actuator System and does

not include operating instructions for the prime mover or the driven devices or

processes. For information about other Woodward products used in conjunction

with the EM-80/-300. please refer to the specific Woodward documentation

supplied with each product.

For specific operating information such as start-up, shutdown, and the prime

mover’s response to signals from the Woodward control, refer to the prime mover

manufacturer’s manual.

Description of Components

The EM-80/-300 system provides an all-electric actuation system for various

prime mover control applications.

The system is intended for use on large diesel, gas, and gasoline engines, and

on all types of turbines, to control the position of the engine fuel racks, turbine

fuel racks, turbine and turbocharger variable geometry, and to perform timing

control.

The EM Driver controls the EM-80/-300 Actuator position proportional to a

position demand signal received from a controlling device. The EM-80/-300

Actuator consists of a high-performance three-phase brushless ac motor that

drives a precision planetary gearbox.

We are a global leader in custom oil flow and temperature control devices

for direct drive and geared engine architectures. We provide aircraft turbine

system performance enhancements via custom flow modulation,

which includes flight critical applications in oil modulation, controlled bearing

cooling flow, thermal management, heat exchanger bypass and your specific valves.

Features & Benefits Highlights

• Leading fuel, oil, actuation, air, and combustion systems

• Innovative systems approach to integrate fight critical, customized functionality while minimizing piece

parts

• Highly reliable and cost-effective solutions delivered within severely condensed program schedules

• High reliability and lower risk with technology based on millions of flight hours

Hydraulic Filter Assembly

The valve is supplied with an integrated, high-capacity filter. The broad range filter protects the internal

hydraulic control components from large oil-borne contaminants that might cause the hydraulic

components to stick or operate erratically. The filter is supplied with a visual indicator which shows when

the recommended pressure differential has been exceeded and thus replacement of the element is

necessary.

LVDT Position Feedback Sensors

The SonicFlo control valves use a dual-coil, dual-rod LVDT for position feedback. The LVDT is factory set

to give 0.7 Vrms feedback at minimum position and 3.5 Vrms feedback at maximum position, when

supplied with 7 Vrms excitation at 3000 Hz.

Trip Relay Valve Assembly

The SonicFlo™ valve uses a solenoid-operated trip relay circuit to operate a high capacity, three-way,

two-position, hydraulically operated valve. This trip relay circuit consists of four functional elements: the

trip relay solenoid valve, the trip relay supply orifice, the hydraulically operated trip valve, and the trip

relay volume.

In the normal run mode, the trip relay solenoid valve is closed, which prevents the trip relay volume from

bleeding to the hydraulic return. As a result, high-pressure oil is fed into the trip relay circuit through the

supply orifice, which quickly pressurizes the trip circuit to supply pressure. When the trip circuit pressure

increases above 1100 kPa (160 psig), the three-way relay valve shifts position so that the common port

connects the control port of the servo-valve to the lower piston cavity of the actuator, allowing the servo

valve to position the throttle valve.

The solenoid valve opens when it is de-energized. Opening the solenoid valve causes the trip circuit to be

connected to drain. This in turn causes the three-way relay valve to shift position so that the common port

is connected to the hydraulic drain circuit, and isolated from the hydraulic supply. As the pressure falls

within the lower piston cavity, the return spring rapidly returns the valve plug to the downward position,

closing the control valve and shutting off fuel to the engine.

Triple Coil Electrohydraulic Servo Valve Assembly

The hydraulic actuator assembly uses a two-stage hydraulic servo valve to modulate the position of the

actuator output shaft and thereby control the gas fuel valves. The first stage torque motor utilizes a triple

wound coil, which controls the position of the first and second stage valves in proportion to the total

electric current applied to the three coils.

If the control system requires a rapid movement of the valve to send more fuel to the turbine, total

current is increased well above the null current. In such a condition, control port PC1 is connected to

supply pressure. The flow rate delivered to the piston cavity of the actuator is proportional to the total

current applied to the three coils. Thus, the opening velocity is also proportional to the current (above

null) supplied to the torque motor.

If the control system requires a rapid movement to close the gas fuel valve, the total current is reduced

well below the null current. In such a condition, port PC1 is connected to the hydraulic drain circuit. The

flow rate from the piston cavity to drain is proportional to the magnitude of the total current below the

null value. Thus, the closing velocity is also proportional to the current (below null) supplied to the torque

motor.

Introduction

The SonicFlo™ valve controls the flow of gas fuel to the combustion system of an industrial or utility gas

turbine. The unique design yields a linear flow characteristic unaffected by discharge pressure up to a

pressure ratio (P2/P1) of at least 0.8. The design also integrates the valve and actuator into a compact

assembly. The key characteristics of this valve are a highly linear critical gas flow versus stroke

relationship at constant upstream pressure. The integral actuator is a single-acting spring-loaded design

for failsafe operation. The actuator includes an onboard hydraulic filter for last chance filtration of the

fluid to ensure reliability of the servo valve and actuator. The servo valve is electrically redundant with

triple coil design. Feedback for the actuator is provided by a dual coil, dual rod LVDT (linear variable

differential transformer) directly coupled to the hydraulic piston.

Near the null current, the four-landed valve isolates the control port from the hydraulic supply and drain,

balancing the piston pressure against the spring to maintain a constant position. The control system,

which regulates the amount of current delivered to the coils, modulates the current supplied to the coil to

obtain proper closed loop position of the valve.