No abstract

This article describes the details of the method designed to combustion engine with compression ignition (CI) during road tests. The method requires simultaneous measurements for the crankshaft rotation frequency, fuel pressure in the injector, pressure in the combustion chamber, air pressure and temperature in the intake system. More, this method utilizes possibilities of the GPS navigation -all the received data is being synchronized with navigation data and saved to the database. Fuel consumption was calculated using the original method based on processing the pressure data from inside the cylinder alongside with the fuel injection parameters, previously received from the injection system and engine tests in the laboratory. Obtained characteristics allow to perform detailed analysis for the engine single work cycle in the transient processes, which are the . Measurements results received with help of the created experimental gear were used to determine CI engine parameters. Those parameters may help in simulation of the engine work inside the vehicle, and could be used in engine parameters optimization tasks.

The results presented in this study present the possibilities of achieving a reduction in operational risk, friction losses, and energy costs for the engine friction and lubrication as a result of optimizing selected crankshaft bearing design parameters. The method suggested in the study is different from the known method of searching for optimal parameters throughout defined quality criteria with other parameters changing within the tolerance field (with consideration of dimension changes during work). Using the simulation model, the operation of bearings has been analyzed in starting conditions.

4WD systems include various constructions aimed at optimal distribution of torque between drive axles. In these systems, it is necessary to apply mechanisms separating the power provided from the engine to drive wheels. Many systems operate on the basis of wet multi-disc clutch or/and dog clutch control with the use of mechatronic devices. However, in view of their reliability and construction simplicity, the most valuable 4WD systems under field conditions are mechanical solutions. Torsen is an inter-axle differential mechanism, where the emerging internal friction moment of this mechanism causes that all kinematic discrepancies between transmission shafts of the front and rear axle of a vehicle produce a change in the distribution of torque, helping to level the rotational speeds of transmission shafts of the front and rear axles. As a result of the phenomenon described, the drive wheels of both axles of the vehicle move with different peripheral speeds, which causes energy losses and wear of tyres on both vehicle axles. This paper presents an analysis of the results obtained in tests on a vehicle with the Torsen system and describes phenomena occurring in the examined system as a result of emerging kinematic discrepancies, which may be caused by such factors as vertical force acting on the wheels of individual drive axles and tyre pressure.