Captive Lead Screw Linear Actuators

Captive lead screw linear actuators are integrated motorized assemblies that convert rotary motion into linear motion using an internal nut design in which one end of the lead screw is retained, or “captured,” within the motor assembly. In this configuration, the lead screw does not rotate. Instead, the motor drives an internal threaded mechanism that forces the screw to extend and retract linearly from the actuator body to push or pull the attached load. Because part of the screw must always remain engaged inside the actuator, the amount of screw extension is inherently limited, making captive designs best suited for shorter travel lengths in compact, mechanically stable motion systems.

The captive lead screw actuators are offered in five NEMA frame sizes—08, 11, 14, 17, and 23. The lead screw and nut threads are coated with PTFE to reduce friction, minimize wear, resist contamination, and help prevent coating flaking over time. To ensure long-term accuracy and durability, each unit incorporates angular contact bearings directly within the motor housing to increase thrust capacity, reduce deflection, and control runout. Factory-preloaded bearings eliminate axial clearance to maintain consistent positioning accuracy and minimize backlash over time. These actuators also support advanced motion control upgrades such as Smart Motor Technology, which can provide up to 50% higher output torque for faster cycle times and improved productivity without increasing the actuator footprint.

Key Features:

• Five frame sizes: NEMA 08, 11, 14, 17, and 23
• Multiple lead screw and nut combinations available per frame size
• Available with standard and anti-backlash nuts
• Three nut styles offer design flexibility: round, square and triangular
• Larger bearing design increases thrust capacity and service life
• Preloaded bearings eliminate axial play for improved positioning accuracy
• Optional Smart Motor Technology for up to 50% more torque