Milan Kljajin

Machining of Spur Gears Using a Special Milling Cutter

Spur gears have a wide application in the machine-building industry. Machining process primarily selected for these gears is hobbing method with modular hobs, or with Fellows cutters. Other methods which can be applied are profiling using the pull broaches, while the finishing can be done by gear shaving or grinding by the Maag, Niles or Reishauer methods. Moreover, in small (or unit) production, they may be formed using discor finger-type modular cutters. The article presents a method for cutting spur gears using a disc-type mill with a variable cutting plate profile. The influence of the number of blades of the presented milling cutter on the accuracy of the worked tooth profile was investigated.

Increasing Stiffness of Constructions through Application of Enhancing Elements

Presented in this work is a study on construction stiffness, based on examination of their neutral lines for various cross-section geometries and different force magnitudes. Investigations were conducted both through numerical simulations and experimentally. The results of numerical simulations indicate that stiffness enhancement reduces deflection in the range of 41-52 %, while the experimental tests showed the reduction of 42-54 %. Also reviewed is comparative analysis between the stiffness results obtained by numerical analyses and experiments, which showed high degree of their compliance. The deviations between the results offered by the two methods are 1-3 %, on average, while in the worst case, which occurs in just a couple of points, the deviation equals 10 %. This study revealed significant increase of element stiffness, which was obtained by employment of additional stiffness enhancing elements.

Matrix of function and functionality as a tool in product development process

Original scientific paper The paper describes the use of MFF (Matrix of function and functionality) as a tool in product development process. After years of analysis of matrix methods, functions and functionalities of the products, we have developed a matrix tool that is designed for a wide range of engineers to help developing of new products or their parts. The paper presents the core of the MFF, that is the mathematical model and the computer application. Basic idea was to create an innovative knowledge base in a specific area that contains at one place the knowledge of engineers acquired during their working life, or during product development. With MFF it is possible to generate completely new products with new functional structures where functions are unambiguously described by physical sizes – influencing the functions.

Theoretical and experimental analysis of mine elevator dynamic characteristics

The paper presents the issues with the dynamic analysis of mine elevators used with underground exploitation of raw materials. Dynamic occurrences are particularly emphasized with those elevators due to the fact that they are facilities with extreme heights (up to 2000 m) and lifting speeds (up to 20 m/s) using the steel ropes. It shows the forming path of a competent dynamic model for the analysis of such elevators. Basic parameters (stiffness and damping) are of changeable magnitude during the lifting, so their values are defined through a combination of theoretical analysis and performed experiments at RTB mine elevators at the town of Bor (Serbia).

Evaluation of DFX Tools in Ecodesign

This paper discusses the essence of ecodesign, respectively three key terms: sustainable development, cleaner production and life cycle management compares traditional product development with ecodesign. The term DFX tools is used to sum up all tools which provide a methodology that is focused on part of a product’s life cycle or focused on one of a number of ways to improve an aspect of a product. In this paper it will be given an idea how it could be possible to valuate DFX tools which is using in ecodesign (the ECO Tools). This paper discusses some similarity of DFX tools with the LCA/LCI tools, as in providing an inventory of the inputs and outputs during part of a life cycle of a product, process or activity. An advice to future users of ECO tools will be also given in this paper.