Bench testing of hydraulic motor for rotary drilling rig. The efficiency results of the two speed hydraulic motor have been presented. It was emphasized that the motor is the main component of the rotary drill drive for use in engineering-geological drilling rig type WIG-200. Design of a test bench located in the ITG Komag has been described, as well as the research methodology.

Keywords: hydraulic motor, rotary drill, drilling rig, test rig.

Compressed air driven vehicles. Ecological city transport. Authors briefly presented current state of the vehicle solution based on compressed air as fuel. The advantages of this solution were pointed out due to the significant reduction in emissions and reduce very dangerous smog found in large urban areas. The author’s solution of the student vehicles was presented as the sample of dedicated transport form. The vehicle can easily be folded, transported i.e. by bus or tram as well as inserted into cabinet.

Keywords: compressed-air, pneumatic vehicle, urban transport.

New directions in technology of resistant hydraulic fluids­ for mining. The paper presents an overview of the most important issues concerning the technology of formulating and application of fire-resistant hydraulic fluids HFA with a special emphasis on polish coal mining industry as a main field of its application. The current standardization of those special products, their chemical and physicochemical structure has been discussed and a number of challenges common during technology creating, production and exploitation along with technological solutions has been presented.

Keywords: HFA, coal mining industry, standardization.

The study of selected NVH properties of the simulator of the linear hydrostatic drive. Authors attempt to identify the hydraulic simulator as the generator of an harmonic vibration and noise source. They pointed out a correlation between the quasi-steady state of simulator work and accompanying noise. The influence of including of an hydropneumatic accumulator in the hydraulic system of simulator were analyzed.

Keywords: vibrations, noise, hydraulic system, hydraulic cylinder.

The use of logic valves in high power hydraulic drives. In the article an analyse the applicability of the logic valves to control the direction of fluid flow in hydraulic systems of high power was described. Logic valves hermetic in both flow directions were analysed. The results of the CFD analysis of flow rate up to 1500 dm3/min were presented as well as static pressure-flow characteristics.

Keywords: CFD analysis, static characteristics.