T. Markowski

Cylindrical Gears with Increased Contact Area – Proposal of Application in Watercrafts Power Transmission Systems

Paper presents the method for obtaining maximum contact pressure of Novikov gears. Described surface strength calculation method is based on Hertz theory of two bodies being in point contact. What’s more the influence of gear position errors on maximum contact stresses has been presented. Also the comparison of Hertz stresses for Novikov and involute gears has been made.

Modelling and Vibration Analysis of Some Complex Mechanical Systems

Development of modern engineering requires technical equipment which is characterized by high stability and operational dependability. This particularly applies to components and assemblies which are employed in the aviation, pharmaceutical and biotechnological industries, and biomedical devices. Each newly produced assembly must pass a cycle of advanced computations and a set of experimental tests which allow it to be used in engineering structures. In many cases the experimental tests are realized in order to verify the analytical results. For economic reasons, the calculations should be executed by using advanced computation techniques and the experimental investigations should be conducted on specially designed test rigs. Such test rigs are required to satisfy specific requirements to guarantee that experiments can be led with high technical quality, and economic reasons demand that the rigs should operate for a long period of time (Friswell & Mottershead, 1995). One of the essential factors, which could disturb or restrict the functioning of devices (rigs and others), are the vibration of the components or assemblies of these systems. So it is advantageous to conduct numerical computations at the design stage, which could restrict the consequences connected with the structure vibration. The rapid development of computer techniques and analytical systems based on the finite element method (FEM) allows a free vibration analysis of large systems of complex design and geometry to be conducted (De Silva, 2005). Some authors, using FEM techniques, analyzed the free vibration of complex structures, which are used as load – bearing elements of building structures (Ansell, 2005). Free vibration analysis of selected steel bridges is conducted in papers of Chung and Živanovic (Chung & Sotelino, 2006; Živanovic et al., 2007). The bridge FE models that are developed are verified on real objects. Zembaty (Zembaty et al., 2006) studied the influence of damage of the base construction frame on the change in the natural frequencies of the system. The gas turbine blade is a very important part of aviation jet engine. Some authors analyzed the influence of friction contact phenomenon in collaboration regions of blades and disk sectors on the dynamic behaviour of the blades (Allara, 2009; Toufine et al., 1999). Some presented results were verified by experimental tests. Free vibration of the blade are developed by Sinha (Sinha & Turner, 2011) using the thin shell theory. The achieved solution includes the effect of warping of the cross – section of the blade. Membrane systems have wide application in different disciplines of engineering. Jaffrin and Tack in their papers (Jaffrin, 2008; Tack et al., 2006) present practical

Automating the modelling process of involute spur gears with straight teeth

In the paper the possibility of using Delphi programming language in the design of the tooth profile was presented. A developed numerical application was used to generate a tooth profile of involute cylindrical gears with modification and without modification. The size of modifications of the tooth root and the addendum was compared with the parameters obtained from the analytical calculations and machining simulation of gears.

Temperature as a Source of Information about the Technical Condition Viscous Torsion Damper

The problem of damping of torsional vibrations of the crankshaft in a multi-cylinder engine is very important from the point of view of durability and reliability of the drive unit of the vessel or ship. Mostly dependent on the technical state of the torsional vibration damper that is located at the free end of the crankshaft. The paper presents selected results of the research that led to the acceptance criterion for assessing the technical condition of the viscous torsion damper.

The analysis of precision of making elements for aeronautical dual - power path gear demonstrator applying venture baty coordinate measuring machine

The paper presents the process of measuring and analysing precision of making toothed wheels for a demonstrator of aeronautical dual-power path gear by means of FDM [2]. A coordinate measuring machine VENTURE BATY has been used in the research. The capabilities of the presented optical measuring machine make it possible to measure spur gears with different modules including small ones (m<1)which is a great advantage of this kind of measuring equipment. Analysing precision of making elements of gears is one of more important stages in creating them [6]. However, it is necessary to remember that the controlling stage should be carried out in accordance with standards concerning measuring toothed wheels defining this activity. The measuring method presented in the paper and the outcome of measurements allowed for designing a demonstrator of dual-power path gear intended for stand tests. The correct operation of a gear is assured by proper choice of constructional parameters of cooperating wheels taking into account materials used in FDM technology. The optical machine BATY is equipped with FUSION software used while measuring and analysing precision and it allows for data processing and exchanging the data with other programming environments. It is, however, restricted by one data exchange format – DXF. With regard to 2D measurement specific character, the machine does not make it possible to control tooth outline and as a consequence, it is possible to measure only gears with straight teeth. On the other hand, the advantage of the above is the possibility of comparing the measurement to CAD-2D model, which makes it possible to analyse the precision of wheels with non-standard profiles (other than envolute ones).