In Chapter 6, the calculation method of elastic contact deformation between roller and raceway is introduced. For a rigid bearing as a unit, its elastic displacement refers to the maximum elastic ground deformation along the direction of load action or the direction concerned by the designer. Since the maximum elastic contact deformation is related to the load of the rolling element, it is necessary to analyze the load distribution inside the bearing before determining the deformation displacement of the bearing. In Chapter 7, the calculation method of the load distribution of the bearing rolling element with single static load and rigid support has been introduced. In these methods, the main displacements of bearing 6, 8 are used. In many applications, these displacements may have important effects on the stability of mechanical system, the dynamic load of other components and the operation accuracy of the system. This chapter will discuss these displacements 8.2 bearing displacements of rigid bearing rings. Using the method in Chapter 7, the maximum load Q of rolling element under simple radial load, axial load or radial axial combined load can be calculated. Palmgren 'gives a series of formulas for calculating bearing displacement under specific conditions, which can be used as approximate formulas. The deep groove ball bearing and angular contact ball bearing, which operate at medium and low speed and only bear radial load, will only produce radial displacement, i.e. 8. = 0, 8, = 4.36x10q (81) for self-aligning ball bearing 6, =6.98 × 102 - (82) dcosa operates at medium and low speed, one raceway is the point contact and the other raceway is the line contact roller bearing 8. = 1.81 × 104 (83) cosa for the radial roller bearing 8. = 1.6sx0_.4) above the given value, the appropriate radial clearance and the displacement caused by the non rigid support diagonal contact ball bearing must also be added under the pure axial load, That is to say, 8, = 0, axial displacement is 8, = 4.36 × 102 (8.5) Tsing aligning ball bearing 8. = 69x10 (8.6) Sino to thrust ball bearing 8. = 5.24x104 (8.7) disina to deep groove ball bearing with axial load, the contact angle a must be determined before using 8.5 type. For the roller bearing with one raceway as point contact and the other raceway as line contact, 8. = 1.81 × 10 (8.8) Sina for the roller bearing with each raceway as line contact. = 7.68 × X10 - ﹣ 2 (8.9) Sina, see examples 8.1 and 8.2. 8.3 preload figure 8.1 of 8.3.1 axial preload shows a typical curve of the relationship between ball bearing displacement and load. It can be seen from the figure that the deformation rate decreases gradually with the uniform increase of load. Therefore, when the applied load exceeds the inflection point on this curve, it is advantageous to reduce the displacement of the bearing. This state can be achieved by axial preloading of diagonal contact ball bearings. The common method is to grind the two relative contact ends of the bearing, and then press them together on the shaft, as shown in Figure 8.2. Figure 8.3 shows the pairs of bearings before and after axial compression. Figure 8.4 shows that the ball bearing preload improves the load displacement characteristic curve. system