How to select an electric linear actuator for speed!

Fast-moving processes requiring precision are understandably taxing, requiring careful and skilled design consideration.  When it comes to linear motion systems operating at high speed, usually with short cycle times, the capabilities of linear actuators used within these can be pushed to the extreme.  Selecting an electric linear actuator that can perform at speed and that will stand the test of time is a challenge, but one that thankfully we are well-versed in!

What is a high-speed linear motion system?

The majority of linear motion actuators built by Matara are designed to work as 3 m/s.  Where speeds over 3 m/s are required, this is generally considered to be high speed. 

What are high-speed linear motion systems used for, and where?

Higher speed linear motion systems are typically found in the food & beverage and pharmaceutical industries, where processes have been automated.  Applications are widespread and include pick and place, bottle filling and material handling. 

What are the main types of electric linear actuators?

The three most common types of electric linear actuators are:

• Ballscrew Driven Linear Actuators: uses a ballscrew mechanism to convert rotary motion into linear motion. The ballscrew consists of a threaded shaft with a spiral groove and a ball nut with a corresponding set of ball bearings that roll between the nut and the shaft. This allows the nut to move in a linear motion along the shaft.
• Belt Driven-Linear Actuators: uses a timing belt to convert rotary motion into linear motion. The belt is typically made of a flexible material, like rubber, that is reinforced with cords to provide tensile strength.
• Rod Type Ballscrew Linear Actuators: also uses a ballscrew mechanism to convert rotary motion into linear motion, but is built differently. It features a cylindrical rod or shaft with a threaded shaft or screws inside it and a ball nut with a set of ball bearings that roll between the nut and the shaft. This set-up allows the nut to move in a linear motion along the shaft.

What types of electric linear actuators are best suited to working at speed?

Whilst ballscrew linear actuators are the most frequently used actuators, they generally perform best at 0.35 to 1.5m/s at stroke lengths under one metre.  Higher speeds can be achieved by adding end bearing support systems, changing the type of mounting selected and the length of the shaft of the ballscrew. Depending on other factors at play, such as the dimensions and material of the screw and the actuators’ use and environment, this could help you to achieve speeds of up to 2.5 m/s, but to take it any further will most likely result in ‘screw whip’, where the screw vibrates and bows as it turns.  This will cause excessive wear and eventually lead to premature failure

To achieve speeds over 3m/s, a belt actuator may well be a more suitable alternative due to its design and material properties. Belt actuators are less prone to vibration at high speeds, and their lighter weight and lower inertia of the belt and pulleys allow for faster acceleration and deceleration.  The belt’s flexibility allows it to adapt to variations in speed and load, reducing stress on the actuator, which can contribute to a longer lifespan.

Is speed the only determining factor?

Selecting an electric linear actuator cannot be based on speed alone.  A number of factors need to be taken into consideration, with the two most important being stroke length and load. 

Why choose Matara for linear electric actuators?

Established in 1995, we are a specialist in linear motion products.  We have a well-established machine shop that allows us to deliver cost-effective linear actuator design and manufacturing to suit a range of industrial applications. We have in-depth knowledge and experience across all aspects of linear motion systems, and our customers trust us to advise on the best product for their application and provide it at highly competitive prices.

If you require further information about our linear electric actuators or any of our other products, please contact us today.