The plastic cage of double-row tapered roller automobile hub bearing is generally used for rolling element (tapered roller) guidance, because it has the characteristics of low quality, high machining accuracy, high coincidence with the roller contact surface, and low noise during operation. At present, many double-row tapered roller automotive wheel bearing products at home and abroad use plastic cages. In use, it bears various alternating loads and impact loads, and is easy to wear and break, so it is particularly important to design and calculate the structural strength of the plastic cage. 1 The value range of the main parameters of double-row tapered roller automobile hub bearings The structure of double-row tapered roller automobile hub bearings is shown in Figure 1. The value ranges of the main parameters are: 4～11 mm; L is 1.5 ~2.5 D; Z is 15-25; 1. ≤coffee ≤2. ; 10. ≤ ≤ 20. . Design and calculation of cage structure parameters The cage structure of double-row tapered roller automobile hub bearing and its main parameters are shown in Figure 2. The parameters are derived as follows. 2.1 The selection of cage beam thickness S Since S is the weakest link in the entire cage, especially in Figure 1 Double-row tapered roller automobile hub bearing Figure 2 The structure of the cage The mold parting structure of the cage, so s must ensure that it is not less than the limit value that meets the strength of the cage. After repeated design, testing and use of multiple products, it can be seen that the empirical value of S is Su003d0. 3 D. Generally, in the specific design, the calculated value S is determined by the formula, and then the value of s is appropriately adjusted according to the bearing capacity. Principle The upper part is a bearing with a small load-bearing capacity, and the cage is appropriately increased by S to improve the use strength of the cage; for a bearing with a large load-bearing capacity, the outer dimension of the cage is larger, and it can be appropriately reduced under the premise that the strength is satisfied. S, Table 1 is the reference value range and preferred value of S for different size segments. 2.2 R. R l and cb determine the cage pressure slope angle 0. Choose 2O ¨, the calculation formula of arc radius is R u003d1. 03 D /2 u200bu200bR lu003d1. O3 D l/2 where the coefficient is 1. O3 is an empirical value, and the value is related to the radial clearance of the roller in the window hole, which can be adjusted in specific design. Figure 3 is a cross-sectional analysis diagram of the small end face of the roller, where c is related to the number z of the cage window L. Fig. 3 Analysis of the small end face of the rolling Fig. 2.3 Dh determination of the parting size of the cage mold The calculation formula for Dhu003dD-2tan0 (0.35/ +It1/cos0) mold parting line size selection It is 0.35/ place (0.35 is the empirical value), as shown in Figure 4. The actual guiding effect of the cage on the roller in the 0.35/dimension segment is very small. The coefficient can be adjusted in the specific design to improve the guiding effect, but the prerequisite is to ensure that the cage The strength of the mold structure meets the requirements of use. 2.4 The representation of the structural strength of the cage is shown in Figure 4. If the outer dimensions of the cage are similar, the change in the cross-sectional area (day) of the cage will have a greater impact on the structural strength of the cage. The cross-sectional area (f.h), c and s are all parameters that characterize the structural strength of the cage. Attention should be paid to the design. In addition, Z can be adjusted when the design strength of the cage meets a certain radial tensile strength. , In order to meet the requirements of the sealed space on the size of the cage. 2.5 h. The calculation formula for determining the thickness h of the small end section of the cage for f l and fc2 is hu003d(O.35/ +It1/cos0)tan0. Generally, when h≥1 mm, the strength of the cage is relatively reliable. If h is too small in the design, the structural strength reliability must be verified. As shown in Figure 4, z. Refer to Table 2 for the values u200bu200bof and z, and refer to Section 2.4 at the same time. Table 2 Selection of ld and nlllD reference value l I The reference value l exceeds 4 6 lJ 0-1.2 2.0-2.46 8 1.4-1.6 2.4-2.68 11 lJ 6- 2.02.6—3.02.6 The center line of the cage. AC. . Confirm the use of AC and 0 (one coffee), 0. , R, D and D. Waiting for known conditions, the two special points A and (Figure 2) on the center line of the cage can be determined. The radial dimension of the point A and can be used as a drawing method or directly substituted into an empirical formula, that is, dAu003d dl+ 0 ．4 D dBu003d d2+ 0.4 After determining the sum of the special point A, the sum of the center line of the cage can be determined. When 0 is calculated, it can be used as a graph method, or the difference of (d-d) can be directly used and kept The frame window hole length z is substituted into the empirical formula 0u003darcsin[(dB-dA)/l] After the center line of the cage is determined, the calculated R and R are used. , S, 0. And other parameters, the cage frame is large and small head opening size AC. And AC (where AC is the theoretical value, only for mold processing reference) can be determined. This article discusses the design principle and calculation method of the plastic cage of double-row tapered roller automobile hub bearing, and stipulates the value range of the main parameters of the double-row tapered roller automobile hub bearing, which is designed according to the method in this article. After years of use, the product has achieved good results.