The Kinitics Linear Actuator (KLA) is a shape memory alloy-based precision linear actuator that delivers high force and high speed in a compact package, making it an ideal linear actuator for positioning applications. Electrically powered, the KLA actuator has only one moving part, the rod, and operates without the backlash common to lead-screw and ball-screw actuators, improving performance in a positioning application. Additionally, in continuous-duty holding operation the KLA Linear Actuator requires little power, making it an efficient alternative to fluid-power options. Forces up to 2,000 N can be generated and maintained within sub-Newton accuracy while strokes up to 8 mm can be held to within 5 µm.

Shape memory alloys for speed, force and precision

From an electrical perspective, the KLA linear positioning actuator behaves as a purely resistive device, with a broad linear region over its stroke where position is linearly proportional to power input. In order to achieve high precision and accuracy, the use of closed-loop control is recommended, with a linear sensor the preferred feedback sensor. Complex communication or control techniques are generally not needed; in most cases a simple PI control loop can be utilized. The KLA linear positioning actuator can be connected to a Kinitics Controller, which drives the actuator and utilizes an analog gain signal (using a 4-20 mA input) or a PWM signal at the Pulse discrete input; in combination with a control system such as a PLC, an effective positioning system can be created.

A typical control loop using a Kinitics Automation KLA Linear Actuator and KCA020 Controller.

 

Efficiency

 

Shape memory alloy wires conduct electricity, and when current is applied undergo Joule heating to obtain a highly linear relationship between the wires’ length and energy input. This relationship makes the Kinitics SMA-based linear positioning actuator ideally suited for positioning applications, as the voltage source can be modulated such that power input matches heat dissipation, holding the actuator at a desired position. Furthermore, in a positioning application little power is required: Less than 8 percent of the actuator’s rated power (and even less, depending on the cooling medium) is required for the actuator to hold its rated load at a set position.

Configure an actuator and request a quote online, or contact us to find out more about using Kinitics Automation’s precision linear actuators in your application!