The temperature achieved at the contact surface of the disc and the pad of a friction brake during its operation has a significant impact on brake performance. Temperature measurement techniques, which are usually available under laboratory test conditions, enable obtaining relatively accurate values of the temperature at the friction surface. However, measuring the sliding surface temperature during the entire lifetime of the brake pad is very difficult due to the demanding operating conditions of the brakes, i.e. the appearance of wear, the presence of water, corrosion, and other immersive impacts. Purely mathematical models for the prediction of friction or contact surface temperature are often complex, and they are affected by a number of limitations. In this paper, an appropriate mathematical model was developed in order to enable estimation of the sliding surface temperature values between the brake disk and brake pads throughout the entire duration of brake application. This is achieved by using the results of the temperature measurement within the brake pad and its processing, by means of an originally developed mathematical model.

Rezime:Višelamelasti frikcioni sklopovi koriste se za promenu stepena prenosa u planetarnim menjačkim prenosnicima motornih vozila. Razvijeni simulacioni model frikcione spojnice i kočnice omogućava simulaciju rada menjačkog prenosnika pri promeni stepena prenosa. Primenom razvijenog modela moguće je na bazi simulacije analizirati prelazni proces pri promeni stepena prenosa i obezbediti identifikaciju relevantnih parametara bez izrade većeg broja fizičkih prototipova. Na taj način obezbeđuje se smanjenje troškova i skraćenje procesa razvoja novih prenosnika snage, uz poboljšanje upotrebnog kvaliteta. Simulacioni model može da se koristi i pri razvoju upravljačkog sistema menjačkog prenosnika za definisanje potrebnih karakteristika njegovih komponenata. Ključne reči: višelamelasti frikcioni sklop, model, simulacija. SIMULATION MODEL OF MULTIPLE PLATE FRICTION CLUTCHES AND BRAKES Summary:Multiple plate friction clutches and brakes are used for gear shifting within planetary gear trains of motor vehicles. The developed simulation model of the friction clutch and brake enables the simulation and the analysis of the planetary gear train transitional processes during gear shifting and provides identification of relevant parameters without making numerous physical prototypes. Costs are thus reduced and time for developing new gear trains shortened, while the product quality is increased. The simulation model can be use additionally in developing steering systems of planetary gear trains for defining characteristics o ftheir components.

In order to analyze the efficiency of a high-speed tracked vehicle powertrain, it is necessary to understand the powertrain workloads in specific working regimes. Experimental tests are conducted on a specific high-speed tracked vehicle, in various terrain conditions, in order to obtain accurate workload data and isolate the maximum workload regimes. From the power balance point of view, the most demanding working regime is the vehicle turning process, so corresponding test results are analyzed with special attention. The obtained results indicate that the slip of the turning mechanism friction elements greatly influences the character of the power balance change.

Motor vehicles are complex dynamic systems due to spatial vibratory displacements during movement, changes in the characteristics of components during life cycle, a large number of influences and disturbances, the occurrence of clearance, friction, hysteresis, etc. The mentioned dynamic phenomena, especially vibrations, cause fatigue of the driver and passengers, reduce the life cycle of the vehicle and its systems, etc. In the general case, the movement of motor vehicles is done on uneven roads (terrain) and curvilinear paths in flat roads (terrains). Oscillatory movements cause loading of vehicle parts, but they also negatively affect human health. Therefore, even in the design phase of the vehicle, special attention must be paid to the harmonization of the mutual movement of the vehicle subsystem, and in particular, the suspension system. Theoretical, experimental or combined methods can be used for this purpose, and it is very useful to have experimental results of vibration of the vehicle subsystems in real operational conditions. Therefore, it is very useful to have experimental results of vibration of vehicle subsystems in operational conditions. Bearing that in mind, the aim of this wpaper was to use the movement of FAP 1118, 4x4 wheel formula, in operational conditions (due to higher speeds - in road conditions) to define laboratory conditions for testing. This is made possible by registering and identifying statistical parameters of registered quantities.

The central component of the tribomechanical system is the lubricant, whose most significant function is the lowering of friction and wear appearing in the contact of two surfaces in relative motion. As a subsystem, tribomechanical systems are integrated everywhere into the technical systems. Apart from more significant applications in internal combustion engines, transmission, and hydraulic systems, there is also a large number of further applications. Due to the poor execution of the tribomechanical system or inadequate application, if it is not fit for the given system, commercial losses may occur measured in billions of euros annually. That is why the significance of the tribosystems is not only technical, but also economic and environmental. The concept of the future successful development endeavors to associate economy and ecology into a complex and noncontradictory system. AE