The relationship between radial clearance and axial clearance of deep groove ball bearings in Fig. 5 Δr and Δa The codes in Fig. 5 are as follows. Oa Ball center Oe Outer ring groove curvature center Oi Inner ring groove curvature center Dw Ball diameter (mm) ree Outer ring groove radius (mm) ri Inner ring groove radius (mm) Contact angle (°) r Radial clearance (mm) a Axial clearance (mm) In addition, in Figure 5, r u003d rrra + ri u003d cot (3) u003d sin () (6) Radial clearance Figure 6 Radial clearance and axial clearance of deep groove ball bearings Table 3 Radial and axial clearance conversion constant K value inner diameter code K60 series 62 series 63 series technical data The clearance of single-row deep groove ball bearings is specified by radial clearance. Of the two rings, one is fixed and the other is both. The amount that can be displaced in the radial direction if it is not fixed or loaded is called radial clearance, and the amount that can be displaced in the axial direction is called axial clearance. The relationship between radial and axial clearance is shown in Figure 5, which can be obtained from its geometric relationship. For the bearing, since (re+ri-Dw) is a constant, Δr, Δa, and a are related to each other. As mentioned above, the clearance of a deep groove ball bearing generally refers to the radial clearance, and sometimes it is necessary to know the axial clearance according to the different parts of use. The relationship between the radial clearance and the axial clearance of the deep groove ball bearing is determined by equation (4), and equation (4) can be rewritten as equation (7). Figure 6 is an example of this. In addition, the K values u200bu200bof various types of bearings are shown in Table 3. Calculation example When the radial clearance of the ball bearing 6312 is 0.017 mm, it is known from the table that K u003d 2.09, so the axial clearance is Δa u003d 2.09 × 0.017 u003d 2.09 × 0.13 u003d 0.27 (mm). (2) Single row deep groove ball bearings with radial clearance and contact angle can also be used as thrust bearings. At that time, it is advisable to increase the contact angle as much as possible. The contact angle of the ball bearing is determined geometrically by the radial clearance and the radius of curvature of the inner and outer ring grooves. Using the relationship of formula 1)~(6), Figure 7 illustrates the radial clearance and contact for the 62 and 63 series. The relationship of the angle; the initial contact angle ao is the angle of the axial load. Once the load is applied, the contact angle will change. Zero hour contact. When ao exceeds 2, it is necessary to consider whether the contact area between the steel ball and the raceway surface exceeds the raceway when the bearing is under axial load (see page A81). Table 4 C3, C4 initial contact angle ao of the deep groove ball bearing working under the condition of only bearing axial load, in order to increase its contact angle, the radial clearance usually adopts a larger clearance than the standard clearance , Several kinds of bearings adopt C3 clearance, the initial contact angle when C4 clearance is shown in Table 4. (3) Angular clearance of single row deep groove ball bearing u003d Ko・1/2 where: radial clearance (mm) outer ring groove radius (mm) inner ring groove radius (mm) ball diameter (mm) ball joint Circle diameter (mm) constant 2{ ()}1/2Dpwtan ≒ u003d bearing code 60 series 62 series 63 series Table 5 Radial clearance and angular clearance conversion constant Ko value Figure 8 Radial clearance and angular clearance μmθ When considering the load applied to the bearing, it is generally a radial load, an axial load or a combined load; under such load conditions, the inner and outer rings are usually regarded as parallel displacements. In fact, due to the eccentricity of the bearing seat, the shaft is deflected or the bearing installation is skewed during the load, and the bearing sometimes works in a state where the inner and outer rings are not parallel. In this case, when the inclination angle of the inner and outer rings exceeds 1/2 of the angular clearance of the bearing described below, abnormal stress will occur, which will cause temperature rise and early spalling. As for the load distribution and the calculation method of equivalent load when subjected to moment load, there have been detailed reports, but first of all, it is important to understand the angular clearance of various types of bearings. Angular clearance refers to the angle formed by arbitrarily inclined to the left and right sides of the two ferrules, one of which is fixed and the other is not fixed. It is closely related to the radial clearance. The angular clearance θo can be approximated by equation (1). The constant K0 is constant according to various types of bearings. The values u200bu200bof single row deep groove ball bearings 60, 62, and 63 series are shown in Table 5. In addition, the relationship between the radial clearance Δr and the angular clearance θo is shown in FIG. 8. The inclination angle of the inner and outer rings is about ±θo/2.