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One of the great challenges of engineering teams nowadays is to overcome long and costly project experimentation phases. One effective way of decreasing such project demands is to come up with a firsthand prototype with high success probability. In order to do so, the project team should rely on robust numerical models, which can represent most of the real-life product behaviors, for instance system dynamics. For rolling element bearings, such dynamic models have to consider the dynamic interactions between its components, i.e., rolling elements and raceways. The only vibration transmitting points on rolling element bearings are the lubricated contacts. Therefore, in order to represent the full bearing dynamic behavior on a numerical model, an efficient transient contact model, which depicts the actual contact behavior, is fundamental.

Heating generation in rolling bearings is a critical point for development and application, specially for heavy trucks. Several problems can occur in the rolling bearing and in the system when the temperature increases. For example, at high temperature levels the rubber sealing can change its proprieties and volume, creating a high interference at the contact with the rings. The grease can also be affected and modify its viscosity, generating a possible leakage, which is not allowed during life. This papers aims to study the heat generation and evaluate, experimentally, the temperature stabilization in clutch release bearings for heavy duty application. With this purpose, several tests were performed and the results were analyzed to find the main factors that can be influenced.

Gear design techniques usually results on heavy drives that are contradictory to the tendency of mass reduction on the modern road vehicles applications. This paper proposes the utilization of a genetic algorithm to design and optimize geometric parameters of a transmission stage comprised of two steel gears. Although genetic algorithm is not an optimization technique on a straight sense, its use is increasing in several applications where the design space is multidimensional. In this study, the first fitness function proposed is a weighted average of critical performance factors on gears design such as total drive weight, tooth contact stress, bending stress and total space occupied by the assembly and the second fitness proposed considers the center distance influence and the tooth contact stress and bending stress. The weights of the average are modified in several simulations.

The main purpose of the lubrication in the rolling bearing is to avoid and to reduce the metal to metal contact, thus it is possible to reduce the friction and to prevent the wear between the balls and the raceways. Consequently, the rolling bearing should work with grease or oil inside to guarantee an oil film between the balls and the raceways, thus this grease should stay inside the bearing. To avoid the grease loss the bearing normally may have a sealing but even so a little grease loss can occur. Hence the present investigation was initiated because of the need to understand a grease loss and the basic parameter that has influence on this. To help the elaboration of the experimental tests was used a DOE technique, thus it was possible to determinate simultaneously the individual and interactive effects of many factors that affect in the grease loss.

In recent years vehicle ergonomists have begun dedicating effort towards the study of human motion in the vehicle regarding moving comfort when using commands such as the steering wheel, gear shift and pedals. Correlation between subjective responses of human comfort and the maximum force achieved during the end-of-travel impact and the average slope of the force-displacement curve during the initial disengagement phase is difficult [1]. When end customers complain about clutch pedal actuation comfort, car salesmen and automakers change the entire clutch system, including pressure plate, clutch disc and clutch release bearing (CRB) to solve the problem and the suspicious root cause lies on the CRB. In most cases, previous analyses showed bearing still functional but strong contamination inside the bell housing, on the clutch and between the CRB with plastic housing and the sliding tube.

The synchronization system was created with the intention to make easy the gear engaging in automotive transmissions. The speed difference of the shafts is reduced during the gearshift operation by means of sliding friction of the synchronizer rings. The constant friction performance can be improved and the wear can be simultaneously reduced either by additives in the oil of the transmission or by careful selection of the friction material for the synchronizer rings. Nowadays, brass or steel meet the requirement of both friction surface and resistance on the driving lugs. The friction coefficient of the surface can be increased by scatter sintered coatings, molybdenum or carbon linings that are joined to the carrier material using complex manufacturing processes. A new concept transforms this continuous friction lining into many single friction elements that are guided by "pockets" in the synchronizer ring.

More efficient and more reliable methods to analyze the performance of the bearing test samples help to reduce validation time during development of rolling bearings. This paper presents a study of the impact on airborne noise and structural borne noise of especial prepared rolling bearings with angular contact submitted for durability tests. The study aims to link specific bearing failures to characteristics in airborne noise and structural borne noise using for instance the “envelope technique”. In the future these patterns will enable more effective online monitoring of failure evolution.

Sustainability is the focus of most engineering projects nowadays. The challenge of taking the efficiency to its maximum, in order to reduce the CO₂ emission, became so hard that even a minor innovation is a relevant step. Among the efficiency villains in automotive branch it is possible to quote the mechanical friction losses. One of the main factors concerning to these sort of losses is the contact pressure in rolling bearings. This pressure is highly influenced by singularities on raceways. Different geometry profiles can be a friction source, affecting the usage and leading to a wasteful exploitation. This paper aims to scrutinize the influence that different abnormalities on raceways has on the contact pressure of high speed and low load axial ball bearings. The study will be based on numerical simulations on a contact calculation software. The contact pressure will be evaluated around the edges of dented, bulged, grooved and ridged profiles.

This paper presents a standardization model for the analysis of rolling bearings in transmission systems. A procedure was applied to assist gearbox prototype development. A solid methodology with robust software, based on international standards, allowed the development engineers to shorten simulation time. In this case, the calculations were performed taking into account system elasticity, which resulted in an exact calculation of the internal load distribution in the bearing, including contact pressure, tilted position and with rolling element profile, considering effects of lubrication conditions and contamination. The program also evaluates the resulting forces of gears, displacement, shaft deflection, contact pressure, stresses, torsion and inclination of the shafts. All the information processed aims at providing safe design, optimal solution and cost impact.