Hydraulic device with constant pump and variable electric motor. New concept of hydraulic drive consists of a constant pump driven by an electric synchromotor with permanent magnets. The basic dynamic and operation features of new unit in selected control systems have been described. The advantages and the profits as well as the problems and the limits of operations have been mentioned.

Servo drives in machine tools. The paper describes selected problems in servo drives of electric and hydraulic controlled machine tools. It focused on determination the velocity gain in these drives. The results of simulation for various factors have been presented.

CFD analysis of flow control valve. This paper presents modelling of a three way flow control valve by the use of CFD tool. FSI unit in simulation of interaction between flowing fluid and movable valve components has been used. Selected results (velocity and pressure distribution as well as flow rate on inlet and receiver port) for step increase of pressure at valve inlet and on pressure changes at receiver port have been presented.

Oil condition monitoring in diagnostic process of hydraulic devices. This paper presents special designed on-board diagnostic system built which can be usefully for diagnosing and monitoring of different hydraulic components. Presented system has been enriched with analysis of hydraulic oil as the source of information about technical state of monitoring objects.

Investigation of the pneumatic brake system with the relay-control valve. The article presents the experimental and the simulation results of the two pneumatic brake systems equipped with the relay-control valve. Simulation results were obtained with the use of the previously elaborated mathematical models. A comparison between the experimental and the simulation results proves a good correctness of the valve model.