In mechanical technique, transmission means appliance which is used as intermediary mechanism between driving machine (e.g. of engine) and working (consumed) machine. The role of transmission is transmitting of mechanical energy from main shaft of driving machine to main shaft of working machine. The selection of transmission is limited by the price of complete appliance, by working environment, by dimensions of the appliance, technical regulations, etc. In mechanical engineering, so as in technique generally, mechanical transmissions are broadly used. Mechanical transmissions are mechanisms which are used for mechanical energy transmitting with the change of angle speed and appropriate change of forces and rotary torques. According to the type of transmitting, mechanical transmissions could be divided into: transmissions gear (sprocket pair), belt transmissions (belt pulleys and belt), friction transmissions (friction wheels) and chain transmissions (chain pulleys and chain). (Repcic & Muminovic, 2007)

The subject of this paper is conceptual design and stress analyses of the composite frame for a special mauntain bike. The existing solutions for frames of this type were analyzed, and the design was conceptualized, which was thoroughly analyzed for extreme loads occurring on the Dirt Jump Mountain Bike Frames. By using the methodology of conceptual design, we have obtained a conceptual solution of the frame, which has been evaluated as optimal one based on a set of criteria. We later confirmed this hypothesis by the stress and other analyzes we carried out to validate the frame, and found that the chosen conceptual solution really meets all the criteria.

This article presents architecture of integrated intelligent computer-aided design system for designing mechanical power-transmitting mechanisms (IICADkmps). The system has been developed in C# program environment with the aim of automatising the design process. This article presents a modern, automated approach to design. Developed kmps modules for calculation of geometrical and design characteristics of mechanical power-transmitting mechanisms are described. Three-dimensional geometrical parameter modelling of mechanical power-transmitting mechanisms was performed in the computer-aided design/computer-aided manufacturing/computer-aided engineering system CATIA V5. The connection between kmps calculation modules and CATIA V5 modelling system was established through initial three-dimensional models – templates. The outputs from the developed IICADkmps system generated final three-dimensional virtual models of mechanical power-transmitting mechanisms. Testing of the developed IICADkmps system was performed on friction, belt, cogged (spur and bevel gears) and chain transmitting mechanisms. Also, connection of the developed IICADkmps system with a device for rapid prototyping and computer numerical control machines was made for the purpose of additional testing and verification of practical use. Physical prototypes of designed characteristic elements of mechanical power-transmitting mechanisms were manufactured. The selected test three-dimensional virtual prototypes, obtained as an output from the developed IICADkmps system, were manufactured on the device for rapid prototyping (three-dimensional colour printer Spectrum Z510) and computer numerical control machines. Finally, at the end of the article, conclusions and suggested possible directions of further research, based on theoretical and practical research results, are presented.

This paper presents the results of an experimental method for determining the efficiency of worm gears. Research into worm gears is primarily aimed at increasing the load carrying capacity, prolongation of life cycle and/or achieving higher efficiency, which can result in a reduction in exploitation costs. A larger share of sliding movement with respect to sliding-rolling movement of gearing contributes to the quiet operation but, on the other hand, causes a significant power loss. Very often, the load limit is not put by the load carrying capacity of gearing but by the ability to carry away the heat caused by friction. In order to design a worm gearbox that would be closer to the optimal solution from the temperature point of view (the heat), it is necessary to determine the operation losses. Besides the geometry of gearing, which influences the efficiency by forming conditions required for the creation of hydrodynamic lubrication, the applied lubricant also plays a significant role. In the research presented in this paper, mineral and synthetic oils were used for the combination of materials CuSn12/16MnCr5 used for gears operating at variable output load and two different rotational speeds.

In this paper simulation model which enables quick analysis of elastic rotor natural frequency modes is developed using Matlab. This simulation model enables users to get dependency diagram of natural frequency in relation to diameter and length of the rotor, density of the material or modulus of elasticity. Testing of the model is done using numerical analysis in SolidWorks software.

In mechanical technique, transmission means appliance which is used as intermediary mechanism between driving machine (e.g. of engine) and working (consumed) machine. The role of transmission is transmitting of mechanical energy from main shaft of driving machine to main shaft of working machine. The selection of transmission is limited by the price of complete appliance, by working environment, by dimensions of the appliance, technical regulations, etc. In mechanical engineering, so as in technique generally, mechanical transmissions are broadly used. Mechanical transmissions are mechanisms which are used for mechanical energy transmitting with the change of angle speed and appropriate change of forces and rotary torques. According to the type of transmitting, mechanical transmissions could be divided into: transmissions gear (sprocket pair), belt transmissions (belt pulleys and belt), friction transmissions (friction wheels) and chain transmissions (chain pulleys and chain). (Repcic & Muminovic, 2007)

This paper presents research results of a mechanical stability of a Sarafix external fixation system, applied to an unstable tibia fracture. A stability analysis was performed using FEA and experimental testing under axial compression. Research was perfor

In this paper, an engineering (stress deformation) analysis of several different models of the main crane bridge carrier with box-shaped cross section on which the rail is located above one of the vertical sheet metals is performed. Stresses and deformations of the vertical sheet metals were analyzed depending on their mutual distance and the thickness of the strap sheet metals. The task was to get the appropriate mutual dependencies of vertical sheet metals stress states. The results could be used afterwards for defining boundary conditions when optimizing the carrier with the box-shaped cross section (i.e. optimization using nonlinear programming with constraints). This could be one of possible ways for the dimensioning of carriers that would be lighter than the existing ones of the same material with equal working conditions. For the analysis CAD / CAE (Computer Aided Design / Computer Aided Engineering) software CATIA V5 has been used.

It is known that the operation of the brake is characterized by the conversion of mechanical energy into heat which results in an increase of temperature on contact's surface of sliding parts. Increased temperature affects the reliability of the brake and reduces the brake lining's life time. It is therefore very important to the design or selection of the brake to know the heating level for the assumed operating conditions. This paper presents an example for checking the temperature of the cranes brake. The set up mathematical model was solved numerically (finite volume method). The used method was tested on examples that have an analytical solution and it can be used for an arbitrarily long period of cranes work.

In this paper, the results of the research of three-dimensional (3D) parameter modelling of different types of standard catalogue gears using CATIA V5 software system. Gears modelling by computers are based on geometric and perspective transformation which is not more detail examined in the paper because of their large scope. Parameter modelling application makes possible the control of created 3D gear model through previous defined parameter which is based on relations and geometric constraints (parallelism, perpendicular, etc.). The final shape of gear changes by changing of values of characteristic independent changeable parameters, and that makes possible model creation in short time. Obtained 3D gear model from CATIA V5 system is used as the base for technical documentation making, analysis of stress and deformation by Finite Element Method (FEM), generating of NC/CNC programs for production of the parts on machine (CAM/NC), Rapid Prototyping (RP), etc. Final taking into consideration shows that functionality of parameter associatively must obligatory apply in interaction with traditional geometric modelling approach that appears until now. Modelling methodology and functionality that is described by selected examples can be used in any category of industry and in any process.