Drawing for illustration of PHS 6-C ISB

DRAWINGS 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.

USE (MOUNTING AND DISMOUNTING)

The spherical plain bearings can be considered in every respect, components of elevated precision. This is because from the experience of the ISB® producers, always alongside the major constructors, has emerged in the majority of cases, that the mounting of spherical plain bearings which are not suitable can lead to machines which are stopped and or broken, often expensively. This is why the product must absolutely not be manipulated, cleaned with unsuitable liquids, or even simply touched with naked hands.

QUALITY OF THE SHAFT AND THE HOUSING OPENING

The spherical plain bearings are normally subjected to loads which are much greater, for this reason the housing seats, the shafts, and the plain bearings themselves must be configured so that the forces which are transmitted do not cause permanent deformation such as to compromise their use

DIMENSIONS, TOLLERANCES AND PRECISIONS

Spherical plain bearings are guidable mechanical components ready to be applied. The dimensions are unified and permit the transmission of both static and dynamic strength in conjunction with oscillating alignment, rotary and bouncing movements in several directions. The internal ring is provided with an external convex spherical surface while the external ring is equally spherical with a concave internal surface. They are available with sliding surfaces realized in a combination of steel on steel and in many other executions which do not require maintenance.