The US linear motion specialist Haydon Kerk has developed a linear actuator that combines the traditionally separate functions of driving and guidance in a single, coaxial component. The motorised SplineRail actuator (shown below) uses a precision-rolled leadscrew, supported by bearings and contained in a concentric aluminium spline, to drive an integrated composite polymer nut/bushing.
When mounted vertically, the SplineRail can be used to lift and rotate simultaneously. With one motor driving the screw and a second rotating the rail, a compact, self-supporting pick-and-place mechanism can be created.
Typical applications are expected to include robotic assemblies, and packaging and assembly systems. The extruded aluminium spline is said to offer good torsional stability, while TFE coatings and self-lubricating nut/ bushing materials are predicted to deliver a long maintenance-free operating life.
Screw leads will be available from 0.05–1.2 inches (1.27–30.5mm) per revolution, providing a wide range of performance profiles, including self-locking threads that can support a load without external power or breaks. The SplineRail is powered by single- or double-stack stepper motors.