E•DRIVE SL Strongarm Sideload Actuator
The E•DRIVE SL Strongarm sideload actuator is a device which, in addition to applying and resisting axial forces, supports
substantial bending moments in the form of forces off-center from the axis of motion as well as forces perpendicular to the piston. Furthermore,
this Strongarm actuator develops this capability without expanding the traditional linear actuator physical envelope, thereby providing significant
added capability without additional space requirements.
Traditional theory and practice has been to isolate linear actuators such as the force tube actuator, as well as their ball screw and ball nut system,
from cantilevered, offset, or any other form of bending moment. One reason is that regardless of the load magnitude, binding (excessive friction)
will occur whenever the moment arm length exceeds twice the distance between the piston support bearings within the actuator. In addition, any
force other than axial, applied to the ball nut, is highly undesirable.
The normal consequence of side loading a traditional linear actuator is malfunction and/or severely shortened life. The commonly recognized
solution is to provide an auxiliary guide and support system to prevent the side loads from being transmitted to the force tube actuator. This requires
additional components external to the servo actuator, which significantly increase the required work envelope.
The E•DRIVE Strong Arm Side Load Linear Servo Actuator addresses and isolates these various bending forces by
providing a compact, unique, internal, adjustable, preloaded, support mechanism. The compensating force profile can be factory or field
preset to the calculated or measured bending moments. This force will vary relative to the extension position of the actuator, in a manner
appropriate and proportional to the bending moments. This patented mechanism enables the actuator to fully perform its traditional, axial
tension and compression functions without encumbrance from simultaneous bending loads.
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