Spacecraft Mechanisms

High Gear Ratio M8 Rotary Actuator

The High Torque M8 rotary incremental actuator is compact, closely integrated design made up of two key elements: a motor and a multi-stage speed reducer. The motor is a small angle permanent magnet stepper with relatively high holding torque. The multi-stage speed reducer offers a large reduction ratio (6400:1), low weight, zero backlash and high torsional stiffness. Co-axial nesting of the motor and transmission drive elements gives the unit low profile geometry. The actuator can be made available in two and three phase motors with optional features such as potentiometer/resolver output position feedback. All of the electrical elements such as motors and position sensors can be redundant with little or no change in actuator envelope.

Compact, closely integrated design made up of a motor and a multi-stage speed reducer
Small angle permanent magnet stripper with relatively high holding torque
Co-axial nesting of the motor and transmission drive elements gives the unit low profile geometry
Available in two and three phase motors
All electrical elements can be redundant, with little or no change in actuator envelope

Specifications	Units	Basis	Data
Output Step Angle	Degrees	Standard	0.0023
Steps Revolution	Steps	Standard	153,600
Harmonic Drive Ratio	-	Standard	6,400:1
Motor Step Angle	Degrees	Standard	15
Max. Output Step Rate	Step / sec (Deg / sec)	Maximum	640 (1.5)
Torsional Stiffness	Lb-in / rad	Standard	3,440
Shaft Load Capability Axial	lbf	Maximum	170
Transverse	lbf	Maximum	240
Moment	Lb-in	Maximum	100
Output Torque	Lb-in	Maximum	450
Unpowered Holding Torque	Lb-in	Maximum	200
Body Diameter	Inch	Standard	1,400
Body Length	Inch	Standard	4.25
Power	Watts	Maximum	10
Through-hole Capability	Inch	Maximum	0.120

Our extensive product offering of Rotary Actuators are flexible and customizable to your specific needs. For more information on Rotary Actuators, or this specific model please contact our Chatsworth facility.