Exlar Tritex II Linear Actuator: Part 1

Exlar Tritex II Linear Actuator Roller Screw Technology

Are you looking for a replacement for your expensive hydraulic or pneumatic cylinders? Would you like an electric solution that is energy efficient, high speed and very precise in movement? This article and Ramco TV video will review the Tritex II servo based actuator from Exlar.

The Tritex II is an “all in one” linear actuator, that combines a mechanical actuator, along with the drive and servo for a complete stand alone solution.

While this article will focus on the linear actuator, the Tritex II package also offers a rotary servo motor. This will include the same options as as the Tritex II and can include integrated gearboxes for your high torque applications.

Before we get into the specifics of the actuator let’s look at the mechanical structure.

Roller Screw Technology

Unlike most linear actuators Exlar’s Tritex actuator is based off of a patented, inverted roller screw. Multiple helical rollers are assembled around a threaded shaft. This is what is converting your rotary movement into linear movement. But why is roller screw better then typical ball-screw designs?

Ball screws have limited contact points inside their raceway which limit’s how much force can be transferred. A roller screw has much more contact surface area which improves stiffness along with a higher load carrying capacity for similar size screws. This design also allows for a much higher speed. Back to ballscrews…. As the balls are rotating around they have to return at some point so they can circulate. This return causes collision, which limits you on how fast it can rotate. Again the roller screw design does not have this problem.

No matter who the actuator manufacture is, when it comes to a mechanical actuator there is life time expectancy. Another key advantage of the roller screw design is life. Exlar actuators, when sized properly and maintained correctly, can be excepted to last in some cases 10x longer then other ball-screw based actuators.

Servo based actuator.

There is not actually a servo coupled to the roller screw…the servo is actually built around the roller screw. Neodymium magnets are epoxied to the out casing so this is now your rotor. The stator is wound around the rotor. Now we have a motor. There is an encoder on the back side of the actuator which gives this actuator its extremely precise precision. The drive is on the top which is programmable via an easy to use software.

The Exlar Tritex can come in a variety of screw leads depending on your force requirements. Standard lengths are available from as short as a 3” all the way up to 18”.
They can also provide various mounts, including clevis, front and rear flanges, trunnions, tie-rods and more to virtually fit most applications. This is a brief overview of the mechanical structure, let’s take a look at what is available on the electrical side.

These actuators come in AC voltage 115-230 volts that can provide forces 4000 pounds continuous and 10000 pounds for a short amount of time. Speeds up to 33 in/sec depending on the lead.
DC actuators are also available from 12-48VAC with forces about 1000 lbs and 1300 lbs for a short amount of time. Speeds up to 33 in/sec.

The Tritex II has a built in controller so no panel space is required to operate this actuator. These actuators have 8 digital inputs and 4 digital outputs. As well as analog in and out for remote speed and torque control. For those who like to have complete control, exlar offer’s communication protocols including serial, Ethernet/IP, Modbus CTP, Profinet, CANopen.

All of these features are housed in the actuator in an IP54 or IP65s rating. Other housing options available with special coatings for certain environments.
You may be thinking: how hard is this to operate? It’s not as difficult as you may think. Exlar offers free programming software that is easy to use.

More and more companies today are thinking about energy savings and how to do processes more efficient and with less scrap. With the Exlar Tritex II you can do just that.