Hydraulic systems of laboratory test stands for investigation of cutting tools and mining heads of shearers and roadheaders. The paper presents two laboratory test stands designed to test cutting tools and new methods of rock mining. Hydraulic systems and functional diagrams of laboratory test stands have been presented and described. Selected results of the laboratory research have been presented along with a summary of operation of both hydraulic systems carried out so far.
Flow-rate characteristics of pneumatic components according to the ISO standard draft. ISO 6358 is a standard under revision now. The test circuit and the measuring procedures have been described in the article as well as many author’s remarks. The authors’ proposal to calculate C, b and m by Solver in Excel has been presented.
Durability investigation of viscotic brake with electrorheological fluid. In this paper theoretical investigation and tests of durability of a viscotic brake with electrorheological fluid have been presented. During the test rheological and electrical properties of the fluid, as well as surface quantity of electrodes and conditions of bearings, were evaluated. Any increase of the dynamic viscosity coefficient of the fluid under an influence of particle crushing in electrorheological fluids has been observed.
Compressing the crane girder in the hydraulic drive. The compression of the crane girder in the hydraulic drive is a way to get a smaller cross section. The possibility of reducing the dimensions and parameters of the component has been pointed out. The process of compression using the proportional control has been shown.
Industry of machinery and equipment in the period of crisis. The paper presents the machine-building industry market and its major shareholders during the recovery from the crisis. Based on the latest data it has been presented and analyzed the dynamics of sales and orders in various branches of machine-building industry. A forecast is shown for the period 2011-2015 for the major economic powers.
