SELECTION OF BEARINGS

SELECTION OF BEARINGS 1. After knowing all about bearings the important thing is the proper selection of bearing for any moving vehicle or machine. 2. The selection of ball & roller bearings for a given installation depends upon the following factors. The load carrying capacity & the nature of the load. The type of service under given conditions such as temperature, humidity, dustiness, acidity, etc. The anticipated life of the bearing. Magnitude and direction of loads. The proportion of thrust to radial load. 3. Cylindrical Roller Bearings are suitable for those shafts which have been allowed to move freely longitudinally within certain limits, and for far larger and heavily loaded applications. Taper Roller Bearings are suitable where radial and thrust loads or any combination of both are required to be handled and in dealing with heavy composite loads as in case of automobile parts. In very high speed spindles and machines only, bearings with precision tolerances are used. 4. The capacity of the bearings decreases as the speed increases. If a bearing operates continuously, its life expectancy measured in hours will obviously be shorter than if operated intermittently. Some types of bearings can carry only radial loads or thrust loads while some types of bearings can carry both radial as well as thrust loads. So if a bearing which can carry only thrust loads is put under radial loads, it will either break or damage the machine into which it is fitted. So, a proper selection is necessary. One major cause for bearing failure depends on selection of bearings. In short the proper selection of bearings is most essential and will ensure the longer life of the bearings as well as the life of the machine in which it is used. If the bearing loads with its directions of the ratio of radial and thrust capacity and speed is accurately determined, its life span can also be established. The necessary bearings size can also be determined. However the selection is so complex that general rules can hardly be drawn up.