Why Pre-Engineered Linear Motion Systems Are a Smart Choice

Machine builders are incorporating more pre-engineered linear motion systems into their machines rather than building bespoke systems from individual parts

The choices and selections of technology available within these standard systems make a specific solution easy to create using proven components.

The resulting pre-engineered system has a guaranteed performance available with a rapid delivery time and, with design flexibility, there is no need for compromise on specification.

Easy, web-based tools can also be used to speed up the process of getting the right solution to cover mounting orientation, loading conditions, move profile, and environmental conditions for each application.

The modern technology incorporated into pre-engineered linear motion systems means many options are available, including long stroke lengths, the capability to manage heavy loads, and precise, repeatable movement.

Highly effective sealing strategies ensure reliable operation with minimum dust or dirt ingress in applications, such as woodworking or painting, and where levels of hygiene require equipment to be tolerant of regular washdown, and cleaning.

Rapid motor mounting systems have great flexibility that quickly enable the use of a wide range of interface dimensions.

A linear motion system is typically used to move a payload and contains a number of parts and choice of technologies to best suit an application. It includes a drive to move the load, a guide system which handles the load, sealing to protect the inner parts of the system, and lubrication, such as grease or oil.

The selection of the right technology to meet the requirements of a particular process can seem complex and, with specific requirements of some applications, a custom built solution may be the only way forward.

This carries risks in the amount of time and cost to design the solution, in addition to the engineering challenges of ensuring alignment, support, precision, and correct sealing of the system.

However, with pre-engineering, the complete solution is supplied fully designed, tested, and working as specified. Overall, these pre-engineered solutions can save machine builders time and money, as well as speed up development cycles.

Wide Choice of Technology

Electro-mechanical linear motion systems incorporate a number of different ways to move payloads, including a ball screw, a lead screw, and a belt drive with choices of guide arrangements.

Each has different benefits and attributes to suit an application. The ball screw offers high thrust and good accuracy; the lead screw has low noise, high accuracy, and high repeatability; and the belt drive features high speed and high throughput capability.

The guide technology used to carry the payload needs to take care of top, side, and moment loads. Again, different designs have different benefits dependent upon the application – and selection of the best option is important.

For complete linear motion systems there are a number of choices, including ball guides, slide (or prism) guides, and wheel guides.

Optimize the Solution

Applications vary in scale, precision, and requirements. Often, small scale applications only have to handle light loads, but absolute precision may be critical in a small spatial footprint and with a high repeatability.

Air grade aluminum extrusions can be used and are easily connected in the necessary planes of motion. In these applications, a round rail guide may be preferred for its low friction and smooth operation and the high precision required can be proven at the linear motion system manufacturing facility, assuring performance criteria is met prior to installation in the machine.

Economical transport of loads in harsh environments can be important in factory automation applications, such as packaging and material handling. Speed and long stroke length are often the key to the best solution.

To optimize the solution for the specific application there are choices of belt or ball screw drives with either ball or prism guides. These devices can be used where the whole length of the drive cannot be supported and have a corrosion resistant steel metal band which is kept in place by magnets, ensuring dust and dirt don’t enter the inner working parts of the system. The prism (or slide) guide units provide very quiet operation, can handle washdown, and are well suited to harsh environments.

As the prism guide runs along the extrusion, it is a cost-effective solution for long lengths with no need for additional bearings. Lubrication felt seals further ensure a very long lifetime for the system.

This lifetime is, however, compromised for heavier duty cycles and a profile rail ball guide is often selected in preference to the prism in these applications.

Although a cost-effective solution for the right application, the impact of the duty cycle on the lifetime of a prism guide is shown in the following specific examples:

A meat de-boning station runs at a 0.25 m/s with a 200 N load over a one meter stroke length. Here the prism guide is ideal, providing more than 100,000 hours lifetime and, with the choice of stainless steel outer and inner workings and sealing, can handle the washdown and sanitary requirements.

A bagging machine with the same 200 N load and one meter stroke length, but operating at 2 m/s can drastically reduce the prism guide life to 5,000 hours. In this application, the use of a ball guide increases the life of the system back to >100,000 hours. Ball guides have lower friction, lower drive torque, and require a smaller motor and gear solution.

There are many more options and configurations that can be utilized from pre-engineered solutions and the selection and ordering process is designed to take minimize the time and ‘pain’ in getting the right solution.

Web-based tools also save engineering time, size the necessary components, and help ensure the optimum system is selected. Complete systems can be ordered using a single part number and a rapid delivery cycle is assured.

Clear Benefits

Using a pre-engineered linear motion system makes in-depth expertise and advanced technology solutions readily available to machine builders. The systems are fully tested, alignment issues are eliminated, life calculations are easy, and the clear support of a single solution provider is available.

They offer a reduced footprint size compared with some alternate bespoke designs and innovative technologies. The systems are designed for easy maintenance and can incorporate high levels of sealing to handle specific environmental conditions.

No matter what level of precision and repeatability, or whether small-scale, light operation, or heavy duty, heavy load performance is required, a pre-engineered solution can be optimized for the application.

The options, configurations, and customization service available today means the benefits of installing a complete, proven linear motion system can be achieved quickly without compromise.