PRODUCT FOCUS BEARING KNOWLEDGE TRAINING INTRODUCTION KNOW MORE SELL MORE WIN MORE ISSUE 137

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1 BEARING KNOWLEDGE TRAINING This training series should prove useful to all employees of Bearings International. These training modules are geared towards improving the technical knowledge of our sales staff so that they can improve their sales performance and productivity. A thorough understanding of our products will assist in offering a professional service. INTRODUCTION Four Point Contact Ball Bearings are a type of single row angular contact ball bearing with raceways that are designed to support axial loads in both directions. They however require significantly less space in an axial direction than double row angular contact bearing designs. For a predominant axial load, a limited radial load can also be supported. These bearings are comprised of a one piece outer ring, and a two piece inner ring and one rolling element and cage assembly of the polyamide or brass cage design. The two piece inner ring allows for a fuller complement of rolling elements to be accommodated. The inner ring halves are matched to the particular bearing and must not be interchanged with those of other bearings of the same designation. The bearings are separable. That means that outer ring with rolling elements and cage assembly can be mounted separately from the two inner ring halves.

2 AXIAL LOAD CAPACITY IN BOTH DIRECTIONS Due to the design of the rolling element raceways with their high raceway shoulders, the contact angle of 35 and the large number of rolling elements, four point contact ball bearings have a high axial load carrying capacity. The axial load carrying capacity is the same in both directions. α=35 (Separable) Four Point Contact Ball Bearing

3 APPLICATIONS Four point contact ball bearings capable of carrying axial loads in both directions are often combined with a radial bearing and used as an axial bearing with radial clearance in the housing. In order to prevent the outer ring from rotating in the housing, larger four point contact ball bearings have two retaining slots in the outer ring. The retaining slots are offset by 180 and are identified by the designation suffix N2. Typical Four Point Contact Ball Bearing Arrangement Due to the high axial load carrying capability of these bearings they are suitable for use in the following applications: Hydraulic Pumps. Automotive: Chassis and Transmissions. Railway Gearboxes. Wind Energy. Electric Motors. Compressors.

4 REQUIREMENTS The environments that these machines work in have specific requirements on the bearings. High Load Carrying Capacity. High Speed Capability. High Positioning Accuracy. High Degree of System Rigidity. Low Energy Consumption. Long Service Life. Easy Fitment. Increased Machine Reliability. High Power Density. (Compact Designs) LOWER NOISE LEVELS REDUCED FRICTION Due to the higher ball quality, improved raceway surfaces and the more precise dimensional and running tolerances, the internal friction as well as the rotating noise level of the application during operation is reduced. Lower friction leads to reduced heat generation and thus a longer grease operating life. As result, higher speeds or an extended operating life of the bearing can be achieved. In addition, this increases the energy efficiency of the application. SEALS MISALIGNMENT Four Point Contact Ball Bearings of the series QJ2 and QJ3 are not sealed and as such are not supplied greased. They can be lubricated using oil or grease. Four Point Contact Ball Bearings are limited in their ability to compensate for shaft misalignment and axial deflections. Both conditions will increase operational noise, and decrease bearing life.

5 SPEED RATING High speeds can only be achieved using four point contact ball bearings if they are subject to pure axial loads. Speed ratings or reference speeds are not speed limits. Speed rating values are based on thermal equilibrium between the bearing and its surrounding components. Reference speeds can be exceeded up to the limiting speed if the loads are only axial and lubricated with oil. CAGES Four point contact bearings with brass cages have the suffix MPA. These window type cages are outer ring guided. Four point contact bearings with brass cages are of an optimised design and are suitable for operating temperatures between -30 C and 150 C. Bearing with brass cages with an outside diameter of more than 240 mm are dimensionally stable up to 200 C. Four point contact bearings with cages made from glass fibre reinforced polyamide have the suffix TVP. Bearings with cages made of glass fibre reinforced polyamide are suitable for operating temperatures up to 120 C. The lubricants generally used for rolling bearings do not have a detrimental effect on glass fibre reinforced polyamide, except for a few oils and greases with a synthetic base oil, and lubricants containing a high proportion of EP additives when used at high temperatures.

6 AXIAL INTERNAL CLEARANCE Four Point Contact Ball Bearings have normal axial internal clearance. (CN- No Suffix) Bearings are available with larger or smaller axial internal clearance. CONTACT INFORMATION Josué Pérez-Sánchez Cell : Tel : For proper functionality, the balls should contact only one inner ring raceway and the opposite side of the outer ring raceway. This is the case when the load ratio is: Fa/Fr 1,27 for bearings in the QJ 2, QJ 3 and QJ 10 series Fa/Fr 1,78 for bearings in the QJ 12 series A load ratio that is smaller than recommended can reduce bearing service life. ISO Social Responsibility ISO Quality Management ISO Environmental Management OHSAS Occupational Health and Safety ISO HIV/Aids Management ISO Information Systems Security BI 24 HOUR HOTLINE: FOR ALL EMERGENCIES