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The primary functions of bearing seals are to prevent lubrication from escaping and foreign material from entering, the effectiveness of which is determined by the design of the seal lips. Bearings with low friction rotation are in great demand in the automotive market as a direct result of enforced vehicle fuel economy and reduced CO2 emissions regulations. Therefore, bearings with good sealing function and low friction rotation are required. This makes designing a seal challenging as the ideologies of high seal-ability and low friction rotation tend to be contradictory. Current estimations of bearing seal friction or rotational torque require significant time and cost through empirical methods of trial and error. Research into the estimation of bearing rotational torque through numerical analysis, based on finite element methods, is the focal point of this paper.

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.

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.

A rotating bearing must have an excellent durability life. Various studies have been conducted for a long time to predict the bearing durability life. However, the bearing durability life has been predicted by an analytic formula in terms of the raceway and ball. A finite element structural analysis has been carried out for a flange, commonly with an assumption of a static load. So it is difficult to consider the dynamic effects (Centrifugal force, Gyroscope effect) of the bearing, which is very important due to its high speed operation. In order to predict the accurate bearing durability life, the dynamic effects must be considered. This paper proposes a method for bearing durability life prediction, considering dynamic effects. Contact between the raceway and ball is one of the important factors to take into account for the dynamic effects of the bearing.

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 ever tightening of fuel economy and greenhouse gas emissions standards globally continues to challenge bearing companies toward lower torque, lower mass products. This paper focuses on improving fuel efficiency by considering the torque of automotive wheel bearing seals. This study establishes the level of drag torque reduction achieved through the structural design of the bearing seals. Wheel bearing seals are a critical component that must pass stringent torque, water exclusion, and other critical OEM and supplier performance specifications. They are designed as non-serviceable and must maintain full performance through the life of the vehicle. As a result of the application of specialized structural design, the drag torque, per the study, is reduced by more than 50% compared to existing bearing specifications. Electric vehicle companies are also seeking low friction wheel bearing solutions to further reduce CO2 (indirect or wheel-to-wheel) emissions.

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.

Through transmitting power and carrying vehicle weight, automotive wheel bearings play an important role. Counterbalancing the bearing responsibilities, they also are designed to last the life of a vehicle without servicing. When mounted to the vehicle steering knuckle by bolts, distortion occurs to the outer ring. Performance is affected when distortion takes place at the seal mounting location and raceways. Finite element analysis using commercial software was performed to analyze the outer ring distortion. Elasto-plastic and contact analyses were carried out to compute the clamping behavior of the outer ring, bolts and the knuckle under various conditions. To verify the reliability of this study, the distortion of the outer ring was measured. The experimental results proved to be comparative with the analysis results.