International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Paper deals with the dynamic behavior of pump unit electric drive. The electric motor, subject of development, is a new standard efficiency induction motor with squirrel cage rotor, designed to operate in continuous operation. The determination of operating characteristics of induction motor in dynamic modes is necessary to establish the properties of the machine in specific conditions. In some industrial areas can occur very often sags with a depth of between 10% and 15% of the rated voltage as a result of switching electrical loads on systems of users. As a result of simulation studies the influences of the supply voltage and total torque of inertia of the electric drive have been assessed on arising impact torques and currents and electric energy losses of electric drive for pump unit. The results obtained are in addition to experimental studies of the same motor. Some of the study results have been presented graphically. An analysis and conclusions from the results obtained have been done

The key issue to an automotive engine’s reliability and its durability is the quality of the lubrication system. The primary task of the lubrication system is to provide a continuous supply of filtered oil between two sliding surfaces. By using adequate lubrication oils will reducing friction between moving mechanical parts. Rheological characteristics of lubricating oil directly caused the friction losses due to internal engines mechanisms (piston group, valve train, fuel pump, crankshaft, bearings and seals, etc.). The main components of lubrication system has a poor lubrication during cold start up process of an IC diesel engine and thus is necessary a proper lubricating oil to full fit the complex demands of all engine components and subassemblies. The aim of this paper is experimental investigating of the influence for different classes lubricating oils characteristics and oil filters which are present in market of Republic of Kosovo, especially those with lower prices on engine oil pressure, temperature and flow during start up until the oil warms up some. The obtained results are taken from measuring device which is installed into Fiat passenger car with Spark Ignition Engine for different working regimes.

The article describes the design and operation of a prototype hydraulic unit. It is based on an inversed kinematics, satellite pump in which the body rotates around the shaft. The pump is placed inside the electric motor. Thanks to that the compact and low mass construction was achieved. Thanks to new commutation unit with enlarged channels, lower pressure losses were obtained. The article presents the construction and results of preliminary tests.

The focus of this paper is the need to achieve energy efficient work regimes in the operation of actual pump systems, because of the impact which energy efficiency has on the utilization of electricity by a system. Some of the main factors influencing the efficiency of a system’s crucial elements also have been examined. A quick and easy method for a quantitative assessment of a pump system’s efficiency also has been presented. The reliability of this methodology has been tested and confirmed. In conclusion, a method for the theoretical determining of the effective work regimes for a centrifugal pump with a trimmed impeller has been given.