In motion systems where motion travels a straight or infrequently curved path, rolling elements and fluid films—also referred to as linear bearings—reduce friction.
They are not to be mistaken for rotating Bearing cage Linear Bushing SRS (รังลูกปืน Linear Bushing SRS, which is the term in Thai). In machine tool applications where it’s crucial to reduce friction and direct linear motion, such as automation settings, 3D printers, and sliding doors, linear bearings are utilized.
It is possible to roughly divide slide types—which rely on lubrication and low-friction surfaces—and ball and roller types—which capitalize on the rolling motion of rolling parts—into two categories.
Self-lubricating polymer linear bushings have taken a portion of the market previously held by sintered metal bushings. The running shaft gets its slipperiness from the polymer itself, which is usually PTFE. Their resistance to washdown chemicals and their capacity to function without lubricants make them attractive in the food packing industry. They can operate on highly corrosion-resistant, unhardened shafts.
Rolling-Type Bearings
When used in conjunction with die posts, open ball cages, also known as guideposts or leader pins, allow the upper and lower dies to close with accurate guidance.
- Ball and roller bearings, both recirculating and non-recirculating, are offered for controlling linear motion. Both of them offer reduced beginning friction when compared to bushings of the slide type.
- Ball bushing rails can span a certain distance between supports and are successfully end-mounted. Profile rail mounting typically needs support along the entire rail’s length, necessitating meticulous surface preparation. However, the number of elements determines the stroke length. Therefore, long strokes could be more practical.
- The majority of linear bearing providers provide a selection guide that walks the user through the design problem. Applications ranging from low-precision ones like drawer slides to semi-precision ones like saw guides and precise ones like machine tools are all taken into account. Numerous suppliers are able to provide systems with multiple actuation choices.
Conclusion
Engineers will need to know a few things before sizing a system, such as the greatest force the system would experience, the length of stroke, and the maximum projected speed and acceleration. Reproducibility is a problem. It is also necessary to take into account moment loads operating on the system along the x, y, and z axes. Maintenance and the amount of noise and vibration all affect the choice of system.
