What is a Motor Frame Size?

What is a Motor Frame Size?

The frame size of a motor defines its mechanical interface to attached actuators. Motors of the same frame size can have different power, torque etc. but feature the same geometrical properties. The length of the motor housing is not affected by the frame size.


Which geometrical values are defined by the frame size?

The frame size defines different geometrical values. Besides the outer dimensions of the motor flange, the most important values are the diameter and length of the motor shaft and the size of a possible key, the mounting hole diameter and the size of the mounting bolts, the bolt circle diameter on which the mounting holes are positioned and the pilot diameter.


Which motor frame sizes are offered with the Norgren ELION?

Depending on the bore size of the actuator, different motor frame sizes are offered. In case of the □067-motor, two different variants with different values for the rated torque are available. Both have the same mechanical interface but have a different overall length.

All motors are available with absolute and relative positional feedback and with or without a mechanical holding brake.


Actuator bore size

Motor frame size and rated torque


□055 (1.05 Nm)


□055 (1.05 Nm), □067 (2.45 Nm)


□067 (2.45 Nm), □067 (3.50 Nm)


□067 (2.45 Nm), □089 (6.90 Nm)


□067 (3.50 Nm), □089 (6.90 Nm)


□089 (6.90 Nm), □115 (10,50 Nm)



Want to find out more?

Read our articles on electric actuators, motors and torque to further your understanding, or use our electric actuator configurator to design and order a custom cylinder.