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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.

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.

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.

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.

Industrial applications frequently use interference between shafts and holes to fix parts together. The present work shows the methodology for validation of Finite Element calculus for press fitting a shaft in a dust shield hole. In the case of study the dust shield can be easily hit by shocks during transport and handling of the product. The shocks would change the position of the parts and consequently the new position could become a quality problem. The process of verification determines the factors which become the project more robust using the technical of Design of Experiment (DOE). The test and the computational simulation are shown as parallel way to determine the appropriate friction coefficient which could be used to predict the assembling and disassembling force for current project as well as the new design with similar features.

Nowadays it is common for engineering applications the usage of software in parallel to test for a better understanding about some phenomena of study. The present paper intents to correlate different software and experimental practices to understand the stress state on the bearing raceway. The most important factor which determines the bearing life is the operational load. Others factors such as the stress state on the raceway due to press fit process can contribute to reduce the bearing life. A large number of factors have been studied to know the behavior of press fit. This paper, treats about the press fit and operational loading.

There are large numbers of variables that affect seal performance, for example, temperature, grease and dusty. This paper aims the study one of these variables, the swelling. Swelling is the absorption of the liquid by the rubber and this liquid absorption can deeply alter physical and chemical properties and hence change tensile strength, extensibility and hardness of the rubber. A review about seal and the characteristics of the seal performance will be made and also a study about what this phenomenon affects the seal performance. Thus the purpose of the present paper is to develop the conception of swelling by investigating the characteristics of swelling deformation.

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.