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The clutch actuation system has the function of convert force made by the user on the pedal to a force acting on the clutch fingers. This system is compound with many components and one of than is the clutch release bearing. The clutch release bearing has direct contact with the finger of the clutch and materials in contact suffer a relative motion. In some case this relative motion is desired and other undesired. Thus this contact surface and the relative motion are important parameters to correct operation and to avoid wear. This paper will study the contact mechanic of this system and for this a large bibliographical review will be made and rise. Basic models and simulations will be developed to visualize the behavior of this system and also some experimental test will be done with different contact surface. This work will help to better understand the contact behavior and design contact geometry for minimum wear.

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.

One of the most important aspects in a vehicle is the driving comfort, thus shift system for manual transmission also has the responsibility for theses aspects. The shift system is a special part for manual transmission where are responsible for the connection between the driver and the car speed, traditionally gear shift is performed by disengaging the clutch, engaging neutral gear, shifting to a new gear, and engaging the clutch again, in a manual transmission the driver can move the gearshift lever transversally to select and longitudinally to engage the gear. This paper will present a research and the function of the shift system components. An overview about the transmission system especially the gear shift will be made, soon this work contributes to the development of new shift gear and also to allow comparison of the systems currently in use.

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.

The water and dust contamination has being studied as an important factor for the components life. For the evaluation of water and dust, it is important that a good method of analysis has been defined. This paper will present a method used to evaluate the grease contamination with dust and water and the actions made to improve the analysis of grease. In order to evaluate the water content in the grease, it was used the Karl Fischer titration. This method determines trace amount of water in a sample. A restriction of this analysis is the grease sample amount, which could not be fully titrated. So just part of the grease (contaminated with water) is analyzed and due to the heterogeneity of the grease and water mixture, this small sample of grease does not necessarily have the same amount of water than the whole grease.

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.