Simple overview of the miniature bearing is introduced

Although the ball and roller bearings is seemingly simple mechanical parts, but they are fairly complex internal geometry relationship. For example, deep groove ball bearings under the thrust load, the ball and the contact Angle between the channel will be coincide with the channel and radial clearance. The thrust load, on the other hand, the bearing capacity depends on the formation of the contact Angle. Produced by the same radial original axial clearance may be accepted by the user, or may not be accepted. In later chapters will show that the radial clearance is not only affect the axial clearance, contact Angle and the stress, deformation, but also affect the load distribution and fatigue life. When determining the stress and deformation, the ball and roller and raceway contact relative alignment is crucial. In this chapter, to control the ball and roller bearings and alidated running basic macroscopic geometric relationships. 2. 2 ball bearings ball bearing is the most simple form is shown in figure 2. 1. Can easily see from the picture bearing the pitch diameter of inner and outer diameters is approximately equal to the average, namely, d. = ( Inside + outside) ( 2. 1) However, more precise bearing pitch diameter should be equal to the mean the diameter of the internal and external raceway groove. Therefore, ( d + d) 5 F miraculously, ball bearings and other centripetal roller bearing, such as cylindrical roller bearing design into a clearance. In figure 2. 1 you can see that the radial clearance ° can be expressed as follows: P = d. - d - 2 d ( 2. 3) Table CD21 in CD from the literature ( 1) , it gives no load centripetal ball bearings inside the radial clearance value. See example 2. 1. Figure 2. 1 have a radial original deep groove ball bearing 2. 2. 1 inosculation of ball bearing capacity depends largely on the rolling element and raceway inosculation. Alignment is perpendicular to the rolling direction of the rolling element and raceway curvature radius ratio of the radius of curvature. In figure 2. 1 you can see, for the ball and fluid passage, alignment is expressed as will = 2 r ( 2. 4) R = D, the inosculation of O like always along the diameter measurement, but as a result of measurement in the radial plane, so often referred to as the radial original. Diameter and radial clearance can meet each other here