Dispelling the Myths Surrounding Linear Guidance Systems

Many engineers are comfortable with rotary bearing technology and view linear as complicated and over engineered with complex maintenance requirements.

Here, Schaeffler dispels the common myths about linear bearing technology:

It doesn’t have to be complicated

Linear guidance systems use rolling elements – balls, rollers, needle rollers – between moving guidance elements that maintain a direction of motion along a linear track – profiled rail, guideway or cylindrical shaft. They are responsible for the guidance and transmission of force between machine parts moving in a translational direction so have a significant effect on the overall performance and accuracy of a machine. The most common types of linear guidance systems are:

• Shaft
• Track Roller
• Flat Cage
• Miniature
• Monorail

A wide range of accessories and sealing arrangements is available for all bearing types depending on the specific application requirements.

There is a linear guidance system suitable for any application

Shaft guidance systems -  are relatively simple guidance mechanisms due to their low to moderate accuracy.  One of the oldest guidance systems based on rolling elements, they consist of a hardened and ground shaft and one or more low friction linear ball bearings, which run back and forth on the shaft supporting high radial loads. Typical applications: power tools (mitre saws); fitness / exercise equipment.

Track roller guidance systems – consist of carriages, composite guideways and track rollers which combine to achieve versatile and cost-effective designs. They are lightweight in construction and offer low noise, high speed and long travel distances.  They support forces from all directions except in the direction of motion, and are highly suitable for handling systems. Typical applications: multi-axis and gantry arrangements; machine guards; packaging machinery; automatic doors; tool changers.

Monorail guidance systems - comprise one or more carriages running on a profiled guideway. The rolling elements are guided by a rolling element recirculation system with either balls or rollers in full complement (maximum possible number of rolling elements) sets. These systems offer extremely high load carrying capacity, rigidity and accuracy. Typical applications: machine tool axes; robots; packaging machinery; paper processing machinery; medical equipment; measuring equipment; palletisers & other mechanical handling systems.

Flat cage guidance systems – are ideal for oscillating motion and applications requiring high load carrying capacity, high rigidity and accuracy with restricted stroke length and very smooth running. Typical applications: gauging equipment; applications with very low section height.

Miniature guidance systems – are characterised by their extremely compact designs, high accuracy, high rigidity and high load carrying capacity with unlimited stroke length. Typical applications: compact medical equipment; machinery for manufacturing electronic components.

‘Maintenance free’ linear guidance systems are available

All INA linear guidance systems can be supplied with precision accessories to enhance the performance of the product and, in some application conditions, achieve maintenance-free operation. These include lubrication systems, measurement devices, corrosion-protected coatings and materials and enhanced sealing arrangements to protect against contamination.

Linear guidance systems can be customised

A Linear Quick Centre is available at Schaeffler to customise and assemble linear bearings  and guidance systems.  This includes the cutting and machining of shafts, track roller guidance systems, monorail guidance systems and ball screw drives to the customer’s specific requirement.