Electric linear actuators use a mechanically connected electric motor to turn a threaded spindle. A threaded nut or ball nut with corresponding threads to those of the screw is prevented from rotating with the screw. As the spindle rotates, the nut is carried along the thread. The direction in which the nut moves depends on the direction in which the spindle rotates, and also returns the actuator to its original position.
Here are some disadvantages related to the sue of traditional electric actuators:
- Due to the rotating to linear mechanism, the movement is rather slow and is in the range of 10 to 100 mm/s.
- Lifespan limitation due to wearing of the lead screw and nut.
- Frequent lubrication of the gears is required.
- A constantly running motor will overheat, increasing wear on the reduction gear. The motor can also be large and cause installation problems.
- The selected motor fixes the force, thrust and speed limits of the drive to a fixed setting. If other values of force, thrust and speed are desired, the motor must be replaced.
In contrast, KOMP-ACT direct drive actuators and linear motors’ movement is provided by an electromagnetic interaction between the iron core stator containing the coils and the rotor containing the permanent magnets.
Here are some of their main advantages:
- Fast speed 2 m/sec., high cycle rate from 300 to 1,500 cycles/min depending on stroke.
- Superior positioning accuracy (better than pneumatics).
- The iron core stator is a 24 or 48 V three-phase stator to allow easy conversion to machines already using a 24 or 48 V power supply. In addition, 24 or 48 V is a low voltage that poses little risk to operators.
- Compared to ironless technology, the tubular stator with iron core allows higher power density and better heat dissipation, which translates into higher motion dynamics (speed and number of cycles).
- The product footprint is also smaller and more efficient thanks to the lower ohmic resistance of the coils.
- To modulate the electromagnetic interactions between the 3-phase stator and the rotor, a controller is required to control the current induced in the 3-phases according to the position detected by the integrated magnetic encoder.
- To save space and cost, each electronic controller can operate 2 actuators simultaneously and independently via an end-user software interface that can be accessed by any Windows-based computer by simply entering the IP address.
- Fast setup within minutes, with no additional accessories or complex coding required.