Aircraft electric
motors
and aerospace actuators
Aerospace electric motors come in many forms and closely allied to actuation. Aircraft
electric motors are used where motive force is needed to drive a valve or an aerospace actuator from one
position to another depending upon the requirements of the appropriate aircraft system. Typical uses for
electric motors are:
• Linear actuation: for aerospace
actuators such as electrical position actuators for engine control; aircraft trim actuators for flight
control systems.
• Rotary actuation: electrical
position actuators via screw jacks for aircraft flap/slat operation.
• Control valve
operation: electrical operation of fuel control valves;
hydraulic control valves; air control valves; control valves for ancillary systems.
• Starter motors:
provision of starting for engine, APU and other systems that require assistance to reach self-sustaining
operation.
• Pumps: provision of
motive force for fuel pumps, hydraulic pumps; pumping for auxiliary systems.
• Gyroscope motors:
provision of power to run gyroscopes for flight instruments and autopilots.
• Fan motors: provision
of power to run cooling fans for the provision of air to passengers or equipment.
Many of the applications for which aircraft electric motors are used are not
continuously rated; that is, the motor can only be expected to run for a small proportion of the
time.
Others such as the gyroscope and cooling fan motors may be run continuously throughout
the period of operation of the aircraft and the sizing/rating of the motor has to be chosen accordingly. It
is possible to categorizes the characteristics of the DC and AC motor types commonly used for aircraft
applications.
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