Woodward 3171A, Руководство по эксплуатации продукта, Страница: 12 / 47

EM35MR1/3171A Gas Valve Manual 26731
2 Woodward
EM35MR1 Actuator
The EM35MR1 actuator is an all-electric actuator designed for use in industrial gas
turbine control applications. The EM35MR1 actuator consists of a high
performance brushless servomotor and a precision planetary gearbox with two
resolver-type shaft position sensors. All stator windings are completely sealed. The
use of a high efficiency gearbox facilitates high servo system bandwidth. The motor
has its own resolver providing motor rotor position feedback, and the other
resolver(s) provides accurate output shaft position feedback. The actuator also has
a slip clutch to allow full speed impact into optional external rigid mechanical stops.
The motor assembly is housed in a cast aluminum explosion proof housing. A
thermal potting compound is used to transfer waste heat generated by the motor,
to the cast, explosion proof housing and out to the ambient environment. Wiring
to the motor is accomplished through two 0.750-14 NPT conduit connections or
two M25 x 1.5 conduit connections into a wiring compartment integral to the
housing. One conduit is for the motor power wires, the other is for the motor
resolver wires. The motor output shaft is directly coupled to the valve input shaft
through the use of a stainless steel torsional coupling.
Resolver
Position feedback is accomplished using a highly accurate brushless resolver(s).
The resolver is directly coupled to the valve metering shaft through use of a
stainless steel bellows and is housed in an explosion-proof enclosure. The
resolver receives its excitation from the EM driver. The EM driver uses a
resolver-to-digital converter to determine valve position using the output voltages
from the resolver's two secondary windings. Resolver accuracy is ±0.05°. Wiring
to the resolver is accomplished through two 0.750-14 NPT conduit connections
or two M25 x 1.5 conduit connections.