In robotics, the precision functioning of mechanical components is required for optimal performance. Bearings, serving as vital components in robotic systems, play a pivotal role in reducing friction and facilitating smooth rotational and linear motion. Robots, like humans, move forward and backward, side to side, upward and downward, and rotate. Robotic bearing motion can be defined as linear motion (back and forth) and/or rotational motion, either along or in between the axis.
Different types of bearings possess unique characteristics that will accommodate these movements. This article delves into the fascinating world of bearings, exploring their distinct types, underlying principles, and their impact on robotic systems.
Rolling Element Bearings
Rolling element bearings are prevalent in robotics and consist of an inner race, an outer race, and rolling elements such as balls or rollers. These bearings are classified into ball bearings and roller bearings.
Ball bearings are commonly used due to their suitability in numerous applications. Their ability to distribute loads evenly, combined with reduced friction, enables efficient rotation in robotic joints.
Roller bearings, including cylindrical, tapered, and spherical, are utilized in robotic applications involving heavy radial loads or misalignment. These bearings provide increased contact area, enabling them to withstand higher loads. In robotic arms that handle heavy payloads, cylindrical roller bearings efficiently support the load while maintaining motion accuracy.
Self-Lubricating Bearings
Self-lubricating plain bearings, incorporating materials like PTFE (polytetrafluoroethylene) or graphite, eliminate the need for external lubrication. These bearings reduce maintenance requirements and are ideal for robotic systems operating in harsh environments or inaccessible areas where regular lubrication is impractical. Radial spherical plain bearings comprise inner and outer rings with maintenance-free sliding layers made from ELGOGLIDE®, PTFE composite, or PTFE-bronze film. They are thus suitable for alternating dynamic loads. Large spherical plain bearings from d = 320 mm belong to the X-life premium class.