Machine Design

1. Forming of a System of Equations Which Describes the Dynamic Behavior of Cable-Crane during Load Lifting
Pages: 45-52
Nikola BABIN, Jovan VLADIĆ, Radomir ĐOKIĆ, Tanasije JOJIĆ
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Abstract

The analysis of the cable crane dynamic behavior during load-lifting is relatively underrepresented in the scientific and professional literature [1]-[4]. Taking into account that usage of steel ropes on large spans (so-called "horizontal rope") leads to systems with significantly higher elasticity than "conventional" steel structures and the fact that the influence on equilibrium conditions, that is deformation (vertical displacement) of supporting ropes under transverse load cannot be ignored (the application of second-order theory is necessary), makes the analysis of dynamic behavior is much more complex [5], [6]. The paper presents the procedure of forming and solving differential equations of motion for cable-crane when lifting a load located in the middle of the span. The process of lifting the load from the ground in two phases was analyzed. The first phase refers to the movement of the supporting structure during the increase of the lifting force which is acting on the load, which is located on the ground until the force in the rope reaches the same weight of the load. The second phase refers to further movement of the supporting structure and load.

2. Design Optimization and Manufacturing Issues of Blisters Obtained by the Thermoforming Process
Pages: 53-60
Aleksandar PETROVIĆ, Aleksandar MILTENOVIĆ, Milan BANIĆ
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Abstract

This paper includes the overview, analysis, and proposals of solutions to certain techno-technological challenges that occur during the whole cycle of development of plastic blister products obtained by a thermoforming process. The paper gives a brief theoretical overview about the thermoforming process and how the process is carried out, describes the types of molds involved in the process as well as certain influential factors. The main contribution of the research relates to the optimization of an otherwise iterative process of design a blister pack for storage printed circuit boards (PCB) and printed circuit boards assembly (PCBA) for electric motors which are primarily used in the automotive industry.

3. Tooth Contact Analysis of Archimedean Worm Gear Drives for the Modification of the Number of Threads on the Worm Helical Surface
Pages: 61-66
Sándor BODZÁS
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Abstract

The aim of this study is the analysis of the normal stress and normal deformation results on the connecting tooth surfaces of worm wheels based on the modification of the number of threads on the worm helical surface. Designing of six gear drives having different number of threads is needed for the mechanical analysis. Knowing of the calculated geometric parameters of the elements the CAD models could be designed. After that the TCA could be done which is necessary before the correct production of the connecting elements. Static analysis will be done by a given load torque. The received results will be represented on charts in the function of the number of threads. The consequences will also be determined.

4. Specialized Elevators for People with Disabilities
Pages: 67-70
Dragan ŽIVANIĆ, Nikola ILANKOVIĆ, Atila ZELIĆ, Kristina JAKIMOVSKA, Anita VASILEVA
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Abstract

Access to higher floors of buildings for people with disabilities is a problem that every society faces and needs special attention. Buildings with staircases represent an architectural barrier and prevent access to the facility for persons with disabilities. In this paper, elevator solutions for people with disabilities will be shown.