Phil Burge, communication manager at SKF, looks at the many innovations in automating industrial processes that can help manufacturers optimise productivity and minimise costs in almost any application

The use of linear motion devices by OEMs and machine builders to position and move parts, work-pieces and tooling in single or multiple axes have been used extensively throughout industry for many years now. As a proven technology, it offers manufacturers extremely high levels of performance for a wide range of environments and in most instances, with a long operating life. They are particularly beneficial in applications that require space and weight savings, with low noise operation at high speeds.

These devices, including actuators, drivers and profile rail guides, have provided manufacturing industry levels of performance, accuracy and reliability to position even the heaviest of moving parts, work-pieces and tooling in single or multiple axes, from aviation systems, laser machinery plant and medical scanners through to high speed factory automation lines.

Actuators for all

The latest linear, telescopic and rotary actuators are capable of delivering high levels of torque, speed, temperature stability and accuracy. For example, standard devices are able to accommodate loads as great as 12kN at accuracies of up to 6µm per 1,000mm, while achieving speeds of up to 174mm/s and travelling as far as 1,500mm. There is now a wide variety of component sizes available to meet functionality and capabilities for specific load and speed requirements for any automation application.

Increasingly, many standard actuators now feature modular designs that make it easy to interchange critical components such as motors, gears, screws and attachments. This ability to custom-build actuators easily and cost effectively from standard parts makes the technology suitable for a diverse array of applications, including many where the use of electromechanical technology has previously been limited. Additionally, it can help to make linear motion systems easier to install and maintain, often with compact dimensions that allow the space required for automation systems to be minimised.

Precision drives

The wide range of driving products such as ball and roller screws fulfills a comprehensive array of functions specifically where compactness, rigidity, precision, speed, acceleration and the elimination of backlash are needed.

Ball screws in particular have been widely used throughout industry for many years, but leading manufacturers, such as SKF, have been continuously developing the technology to meet changing market demands. As a result, ball screws continue to be popular for many applications in providing a cost effective combination of reliability, accuracy and robustness. Offering particularly high levels of precision and repeatability, with optimised design minimising frictional losses, noise and heat, the use of advanced materials with excellent mechanical characteristics has reduced size and weight, while improving overall performance.

Integrated guides

Traditionally, linear guides were supplied as standalone units that needed to be combined with a driving element. This could be a relatively time consuming and expensive process, typically involving engineering a ball or roller screw into positioning systems, often with specially developed ancillary guide mechanisms.

Today, machine builders and manufacturers of linear motion systems are working together more closely to develop complete assemblies or sub-assemblies that are pre-configured and tested off-line, to minimise machine build time and costs. Perhaps as importantly, this process is also helping to increase the performance and functionality of linear motion devices and ultimately machine systems.

It is becoming increasingly popular for leading manufacturers to integrate these individual linear motion components and deliver subassemblies that serve as self-contained units to provide enhanced performance, in terms of speed, strength, accuracy and reliability, while reducing machine costs and build time.

Diversity in operating and control

In addition, a growing range of controls and operating devices is expanding the environments in which conventional linear motion devices can be beneficial and includes foot and hand or desk operated controls. Additionally, control equipment is compatible with all readily available stored program control systems (SPS) and, likewise, with all available bus systems. SPS programming for all electric drives has proved to be particularly simple and the control response remains practically constant for as long as the machine is in operation.

Improved production

With considerable progress over the past decade, linear motion technology is well placed to meet the demands of industry, whether it is a ready to install unit, or an integration of linear motion components that can be used to create a bespoke system.

This new generation of even stronger, more robust linear motion devices can operate even in demanding operating conditions. Consequently, linear motion can provide accuracy and reliability with minimal maintenance or manual intervention. This, in turn, makes a considerable contribution to improving productivity and profitability.