DRAWING FOR ILLUSTRATIVE PURPOSES ONLY.
MOVEMENTS OF SPHERICAL PLAIN BEARINGS
The spherical plain bearings have been projected to resist heavy loads with oscillating, bouncing and rotating type movements. The oscillating movement is translated as movement of the two rings of the bearing, one with respect to the other around the axial of the bearing itself. The width of this movement is expressed by the angle of oscillation. The bouncing movement foresees the internal ring moves in a transversal sense with respect to the external ring.
LOAD
The applicable load is surely one of the principal elements which influence the duration and the choice of the spherical plain bearing. Together with the load, other elements must be considered, such as the movement, the duration, and the maintenance if foreseen. The choice of the dimension of the bearing varies when the load as well as the direction and sliding coupling vary.
TEMPERATURE
If high temperatures are reached, the life of the spherical plain bearing diminishes and proportionally, so does the efficiency of the seal. In cases where the application of spherical plain bearings (with seal) is not possible, spherical plain bearings followed by external seals or the use of lubricants, with shielding, that guarantee good thermal resistance would be indicated.
FRICTION
During the life of the spherical plain bearing, the friction values are not always equal. In fact, in the initial and final phases the friction values are higher while friction values on a well-run spherical plain bearing are noticeably lower. It is however a good idea, for security reasons, to always use the highest values as a reference. Should the friction coefficients surpass the values indicated, greater wear and tear would be generated, increasing the temperature and eventual inconvenience of the functioning.
LUBRICATION
In a general sense, the lubrication of the bearings is particularly important, because it leads to a reduction in friction, protects from corrosive external agents, and acts as a separator from the sliding surface. The choice of lubricant to use is determined by different factors, for example: load, direction of the load, angle of oscillation, speed, and ambient condition.
PROTECTION OF THE SEAT
In order to obtain a good functioning and correct wear of the spherical plain bearings it is fundamental to use protection from eventual external contaminating agents (dust, humidity etc…) applying an adequate amount. A possible setting which is very simple and effective could be given from the layer of grease used for lubrication. With constant maintenance, this type of setting gives excellent results in particular functioning conditions.