This type of bearing has a contact angle, so it is suitable for bearing axial load in one direction, or composite load. Structurally, the axial component of force is generated after bearing the radial load, so two or more bearings should be used facing each other. Single row angular contact ball bearings can be preloaded to increase rigidity, so they are suitable for machine tool spindles with high rotational accuracy (refer to page A241). Generally, the angular contact ball bearing cages with contact angles of 3 (code A) and 4 (code B) are in accordance with Table 1. However, synthetic resin cages or polyamide molded cages are also used according to different conditions of use. The basic load ratings described in the dimension table are based on the cage classification in Table 1. In addition, if the number of balls in the same bearing model is different due to the different cage structure, the rated load is also different from the value stated in the dimension table. Angular contact ball bearings with contact angles of 15° (code C) and 25° (code A5) are mainly suitable for high-precision or high-speed rotation, using copper alloy or synthetic resin cages or polyamide shaped cages. The normal maximum operating temperature of the polyamide forming cage is 120°C. Generally, large bearings use copper alloy car-made cages, with inner ring guide cages (Figure 2.1) and rolling element guide cages (Figure 2.2). Angular contact ball bearings have different contact angles. Even under the same load, the load state of the contact part of the ball and the inner and outer rings is different, and the amount of elastic deformation or contact stress is also different. As shown in Figure 3, the relative load state of the rolling elements at a contact angle of 15° and 3 is used to illustrate. The relationship between the axial load of the bearing and the load of the rolling elements is rolling element loadu003dFa/(ball number×sinα). Therefore, the larger the contact angle, the smaller the rolling element load, and the load on the contact part decreases, and the displacement caused by the load Also reduced, the life of the bearing is prolonged. Conversely, when subjected to radial load, the smaller the contact angle, the smaller the rolling element load, and the load on the contact portion is also reduced.