A Closed-loop Control for Swing System and Energy Regeneration Analyses of the Multi-system of Grasp Steel Machine

Facing the environment problems, the improvement on the efficiency of the construction machinery is highly demanded, meanwhile, large energy wasted in hydraulic slewing systems, reaching the desired speed slowly and vibration in braking are widespread. In this paper, a closed-loop control swing system (CCSS) is proposed. In this system, bidirectional variable pump controls the change of oil flow by programmed software algorithm, instead of pilot actuated reversing valve, which significantly improves the efficiency of hydraulic circuit. Based on the model structures, we develop a hydraulic swing prototype and verify the advantages of our design means of theoretical calculation and simulation. It verifies that CCSS and based on accumulator slewing system(BASS) can respectively save 875.5 KJ and 347.2 KJ more than OCSS with operational weight of 100 tons grasp steel machine, which can support theoretical basis for energy conservation and environmental protection to study the new type of engineering machinery.

Nazi Fordismus

This chapter investigates Nazi Germany's efforts to acquire American mass production technology in order to create their own version of Fordism in the Thirties. Unlike the Soviet Union, Germany boasted a highly developed industrial base in its own right, centered around classic producer goods, such as coal, steel, machine tools, and instruments. Though Germany's machine tool builders were a proud and venerable branch with considerable export clout, they were unequipped to supply mass production factories. Acquiring automotive mass production was of neuralgic significance: it not only harbored the potential of a growth-generating consumer and export sector, but it was also — more immediately urgent to the Nazi regime — of primary military-strategic significance. Accordingly, the Nazi regime did not purchase bulk machinery and entire technological systems wholesale, Soviet-style. Instead, it resorted to targeted industrial reconnaissance and the recruitment of American specialists — that is, to Detroit missions such as those of Ferdinand Porsche, Otto Dyckhoff, and William Werner. The Nazi regime ensnared the American multinationals operating in Germany in a web of political pressure and economic incentives, and in doing so found ways to appropriate the Americans' technology without spending significant amounts of US dollars.

Modal Analysis of Grasping Steel Mechanical Boom Based on ANSYS Workbench

In order to solve the problems that the vibration and deformation of grasping steel machine’s boom can affect machine’s reliability and stability under complex work conditions, the crawler electric grab steel machine JK321-GD is taken as the research object. And then the three-dimensional modeling is established by UG software, the modal analysis of grasping steel machine’s boom is also conducted using ANSYS Workbench, arriving at the the dynamic characteristics of the boom, including the natural frequency, the maximum amplitude and the main vibration direction. These provides theory basis for further optimize design.

Anodic-modified anticorrosive coatings

Steel machine parts are exposed to electrochemical corrosion. This applies to many environments including atmosphere, soil, water, and even various fertilizers. High-carbon steel and low-alloyed steel are not stable (in terms of thermo-dynamics), do not feature effective passivation, and even the corrosion products do not form a stable protection layer. As a result, special anti-corrosion protection is critical. In heavy-corrosion environment, paint systems containing Zn have proven to be very effective. Presented text describes verification of paint systems with high Zn content and compares them to galvanic Zn coatings. Steel samples with protective coatings have been tested in condensation chamber with neutral salt-spray. This way, corrosion resistance of Zn-rich paint systems and galvanic Zn coatings has been evaluated and compared. Galvanic Zn-coatings have shown complete decomposition during the chamber exposition. Thus, further testing was adopted for paint systems only with a special attention being paid to gradual degradation of anti-corrosion layer. Final part of the text lists reasons of coating degradation process and outlines possible solutions of the issue.