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Automotive wheel bearings have the primary function of translating the rotating motion of the wheels into linear vehicle motion while supporting the vehicle weight. As vehicle lives continue to increase, there is a need for longer service lives than those of existing products. There is an even greater need for performance-related reliability during usage. Lateral stiffness, one of the main parameters of wheel bearing design, has a significant influence on ride comfort and steering feel. In this study, reliability-based weight optimization considering geometric uncertainty for automotive wheel bearings was investigated. Deterministic design optimization (DDO) and reliability-based design optimization (RBDO) were performed. For optimization, the following three key relationships were chosen: wheel bearing specification and geometry for design variables, weight for cost function, and stiffness for constraint.

Automotive wheel bearings have primary functions of translating the rotating motion of the wheels into vehicle motion while bearing the vehicle weight. The life of automotive wheel bearings can be divided into raceway life and flange life. Of the two lives, flange life is the failure mode in which the wheel flanges begin to fail. The wheel flange life can be numerically predicted through fatigue analysis. Flange fatigue life requires analysis including rotation due to the bearing characteristics. Therefore, flange life evaluation of wheel bearings can be identified through actual road load test data by mounting wheel bearings on actual vehicles. This paper discusses a fatigue analysis method for automotive wheel bearings using actual road load test data to calculate wheel flange life. Stress analysis and fatigue analysis were performed sequentially using commercial software.

Automotive wheel bearings have primary functions of translating the rotating motion of the wheels into linear vehicle motion while bearing the vehicle weight. Bearing life is affected by many parameters such as bearing geometry, vehicle and bearing technical specifications, driving conditions, lubrication conditions, material properties, and so on. In this paper, the optimization of bearing life was performed. Optimization formulation with no constraints was established to solve this problem. The large scale generalized reduced gradient, LSGRG, algorithm was applied to calculate the basic rating life and modified rating life proposed by ISO 281:1990 and ISO 281:2007, respectively. The optimization history for design variables and cost function were investigated. The results showed that the optimized basic rating life and modified rating life increased about 15% and 31% comparing with those of initial life, respectively.

The role of a brake disc is to convert the kinetic energy of automobiles into thermal energy caused by friction between the brake pads and disc surfaces. The braking performance of an overheated disc is decreased due to hot judder and fade. Hence, the cooling technology of a brake disc is one of the most important issues related to automobile safety. In the present study, the fluid flow and heat transfer analysis of a ventilated brake disc are conducted numerically. Some geometries of automotive parts such as bearings, hubs and wheels are considered in this study. The commercial code ANSYS CFX is used to simulate the fluid flow and the conjugate heat transfer which includes conduction and convection. To evaluate the cooling performance in each case, the results, including the flow patterns of cooling air inside the wheel and the heat transfer coefficient distribution at the disc surfaces, were investigated and compared for various disc-hub combinations.

Automotive wheel bearings have primary functions of translating the rotating motion of the wheels into linear vehicle motion while bearing the vehicle weight. Bearing life is affected by many parameters such as bearing geometry, vehicle and bearing technical specifications, driving conditions, lubrication conditions, material properties, and so on. In this paper, both the basic bearing rating life and modified bearing rating life were evaluated using design of experiments. Bearing lives were calculated by the international standard, and the factors affecting bearing life were investigated. Sequential experimental designs were applied. First, screening experiments were performed to analyze the factors affecting bearing life. Next, confirmation experiments were carried out to determine accurate effects of the selected factors from the screening experiments. As a result, contact angle and curvature of inner ring were significant at a 95% of significance level.