Most of the structures and equipment can not do without bearings. Load transfer and movement occurs by means of rolling elements located between the rotating discs and rings. This design reduces friction to a minimum. If we compare the anti-friction bearings and plain bearings, in certain circumstances they can, to varying degrees to meet the requirements associated with a number of conditions – installation, operation, appointment of products (mechanism). Just at the same duty bearings have a big advantage over the bearings, as at the start and at moderate frequencies have a minimum of friction.
On the plus You can add: ease of maintenance and lubrication, low cost, small-amplitude oscillations. When the node fails replace the bearing of this type is not difficult, since the dimensions and tolerances are standardized. K cons of rolling bearings can be attributed large radial dimensions and high resistance to rotation. Sliding friction that exists between the separator and the working elements of the bearing has great influence on performance characteristics, in consequence of this, during the development and creation of high-speed machines are used bearings that operate in the presence of liquid lubricant. Material that lubricates, is a structural element of the equipment depreciation which it prevents.
The main factors that should guide you when you choose roller bearing: 1. Scope of use and the load. 2. Kind of load – a variable, constant, shock or vibration. 3. Rotational speed – the number of revolutions per minute. 4. Required bearing durability. 5. Terms of bearing operation – the temperature, air, water, vacuum, dust, etc.