Bearings are used in a rotating machinery to provide a support to the load and location of the shaft along with maintaining the rigidity of the system by dropping friction. So, a designer needs to consider a number of factors before making a choice of the thin section bearings perfect for the application, which are given below.
· Design Envelope: The bearing design is a vital parameter to be considered for a reliable and a long lasting choice of bearing according to the application. The bore diameter of the bearing is determined significantly on the basis of shaft diameter and power design of the machine. Ball bearings are good for small shaft diameters, while large diameters fit perfect with deep-groove ball bearings.
· Loads: The magnitude and the direction of the load in an application are used to consider the right type of the bearing. A roller bearing is considered to have a higher load capacity than ball bearings of small size, while the need of radial, axial or any directional combination of load must also be considered.
· Misalignment: There are many cases, which can produce a misalignment of the shaft with respect to the rotating equipment’s housing. However, a rigid bearing can be used to counteract with such misalignments, a self aligning bearing provides the necessary compensation for the misalignment. The range of the misalignment value must be considered to make a better selection according to the application, for which the bearing will be put to use.
· Precision: The precision of a bearing is required to be high, when it is used in those applications that need high speed and accuracy of running. A proper precision reading for a bearing is produced according to the requirement of the application on the basis of the tolerance class, to which the bearing actually belongs. With this approach, a reliable blueprint for the bearing is created.
· Speed: A bearing is limited to a certain speed level due to its design, material and the temperature , in which it can be operated. Along with this, the type & size of the bearing, load, lubricants, precision, accuracy, cooling conditions, internal clearance and cage design also decide the capability of its speed. A reference value is designated with every bearing which determines its operating speed under different operating conditions.
· Stiffness: A bearing stiffness is similar to that of a spring, which is illustrated by the bearing’s magnitude of its resilience (elastic deformation) under a load. In general terms, this resilience has a very small magnitude, which can be neglected, however, in a few cases, the stiffness can be critical like in arrangement oh pinion or spindle.
· Preload: The use of a preload in a bearing is used for the enhancement of stiffness along with other advantages like longer service life, shaft accuracy promotion, compensation for wear and tear, reduction in running noise and others. Depending on the type of the bearing that you choose, the preload must be either an axial type or a radial type.
With a complete evaluation of the above parameters, thin section bearings suitable for a particular application can be selected.
