Bogdan Kozik

Defining influence of load conditions on distribution and value of stresses in dual-power-path gear wheels applying FEM

Purpose – The analysis, carried out for this publication, concerned checking the nature of mating of gear wheels with different load conditions. The computation was made applying FEM in Abaqus 6.10-1 program and concerned spur gears in dual-power-path gears made of ABS. The same geometrical models, material parameters and boundary conditions were assumed for all the analysed stages of the computation. However, the values of torque transmitted from active wheels to passive wheel of the gearing were changed. The paper aims to discuss these issues. Design/methodology/approach – Observing changes of stress levels for toothed wheel and pinions allows to state that for relatively low load values, bending stresses at tooth root change proportionally to the change of the applied load. Findings – Values of contact stresses on mating teeth flanks were also defined for the most loaded part of the dual-power-path gearing, namely for a pinion. In case of contact stresses, it was observed that together with constant in...

Manufacturing of aircraft engine transmission gear with SLS (DMLS) method

Purpose The purpose of this paper is to present the methodology for manufacturing of aircraft transmission gears using incremental method of rapid prototyping (RP) – direct metal laser sintering (DMLS). The production of prototypes from metallic powders using described system allows the execution of final elements of complex structures with additional economic impacts. Design/methodology/approach The paper describes the use of selective laser sintering method (DMLS) by EOS Company. Whole chain of production of prototype is presented with the addition of geometric accuracy measurements by blue light laser device. Findings Presented in the research analysis of SLS/SLM technologies as rapid manufacturing systems shows that they can be applied in the production of prototypes used in the manufacturing process of gears for propulsion systems in aviation industry. Also, very important is the geometrical accuracy of gear prototypes produced by incremental methods. It determines subsequent treatment steps for aircraft propulsion system gears. Practical Implications The use of RP techniques as an alternative for conventionally used manufacturing method has mainly an economic impact related to the cost of time-consuming process and amount of defected elements appearing in serial production. Originality/value This paper presents possibility to use RP – DMLS system – for propulsion elements of aircraft structure. This research is original because of the complex description of the whole chain of manufacturing process. Additionally, geometrical accuracy measurement methodology by blue light presented with the RP method of manufacturing gives the research a unique characteristic.

The assessment of geometric accuracy of aircraft engine blades with the use of an optical coordinate scanner

Purpose The purpose of this paper is to present coordinate measuring system possibilities in the meaning of the geometric accuracy assessment of hot zone elements in aircraft engines. The aim of the paper is to prove that this method, which uses blue light and is most sufficient and cost-saving method, can to be used in the production line for serial manufacturing of elements, for which a high level of accuracy is required. Design/methodology/approach The analysis of the geometric accuracy of the blades was performed using non-contact optical coordinate scanner ATOS Triple Scan II Blue Light, manufactured by GOM Company, at the Department of Mechanical Engineering, Rzeszow University of Technology. Geometric analysis was conducted for blades manufactured from different waxes (A7Fr/60 and RealWax VisiJet CPX200), thus comparing injection technique and rapid prototyping (RP) method, and for casting made of Inconel 713C nickel-based superalloy. Findings The analysis of the criteria for the method of blades’ measuring selection showed that the chosen system successfully met all criteria for the verification of blades’ geometry at the selected stages of the process. ATOS II optical scanner with blue light technology allows measurement almost regardless of daylight or artificial (white) light. This allows the application of the measurement system in the production cycle, thus eliminating the need to create special conditions for measurements. Practical implications Requirements related to the accuracy of measured values, diversity and allowable measurement time are linked with the methods of production. Modern manufacturing methods based on computer-aided design systems/manufacturing/engineering systems require a non-contact optical measurement method based on the computer-aided-based coordinate measuring technique. In case of the non-contact optical scanning method based on the ATOS GOM measuring system, time and measurement costs depend on the methodology of measurement and the possibility of its automation. This is why the presented paper has a practical impact on possibilities for the automation of geometric accuracy measurements of obtained elements in the series production line. Social implications The use of ATOS Triple Scan II Blue Light by GOM Company allows the reduction of cost and time of production because of the possibility of the introduction of this system in an automated production line. Additionally, the measurement of hot section blades of aircraft engines by using the blue light method is much more accurate and has implication as it impacts safety of further used manufactured elements. Originality/value This paper presents the possibility of using the ATOS Triple Scan II Blue Light measuring system for geometric accuracy measurements in case of hot section blades of aircraft engines. This research is original because it describes three model geometric accuracy measurements, wax model obtained using the injection technique, wax model obtained using the I RP process and casting made of Inconel 713C nickel-based superalloy.

Universal test stand for research of aeronautical multi - power path gear demonstrators

Gears used for the tests may be made of metal or plastic [1, 2, 5]. The stand has been designed in an open system and it is powered by a three-phase electric motor. The control is provided by a single-phase inverter with three outputs, which provides full speed control. All components have been installed on a table equipped with T-slots in order to determine the optimal position of the drive and the tested gear. The load of the stand is realized by an electromagnetic powder brake. Load torque of the gear depends on the supplied current. During the test, you can change settings such as speed or load torque. Torque meters installed on input and output of the demonstrator let you control the work of the whole gear. Values supplied by the torque meters (torque and speed) are recorded on a computer in real time (according to PC RTC) and archived by specialized software. The software installed on your computer allows you to view results of the measurements. The possibility to control working time lets you precisely define the time intervals of various stages of the research. Using timer makes it possible to observe the current consumption of the transmission and helps to establish the research process. Thanks to data, recording you will know when the gear is damaged. Tests at this stand allow for obtaining stable working parameters, and thus for obtaining not distorted, accurate results of the demonstrator operation. Changing the gear is exceptionally simple because of the use of sliding splined connections of the couplings. Separating couplings between which the gear is situated and unlocking, the terminal allows exchanging it.

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).

METHODS OF MEASUREMENT OF CYLINDRICAL GEAR AIR, GEAR WITH STANDARD SOFTWARE CMM

Air gears must meet high performance criteria for accuracy; therefore, quality control is necessary for their production. CMM Software determines the capabilities and scope of the measuring machines. Measuring machines equipped with specialized software for the measurement of the gears are commercially available. An example might be a company offering Wenzel TGEAR XY software. This specialized software for the measurement of gears allows fully automatic measurement of the contour deviation (involute), line tooth pitch, and radial run out, tooth flank topography. If you do not have a special software to measure the gear, you require a measurement process based on 3D CAD model of the gear. It is necessary in this case, the preparation of a strategy based on measurements of 3D CAD model and load points or paths with the CAD model. The results of the measurement refer to the CAD model treating it as the nominal model. Item will present the methodology of measurement of cylindrical gears using a standard CMM software. Cylindrical gears can be measured through non-contacting or contacting methods – measuring point or scanning. The choice of measurement method should be carried out taking into account the accuracy of gear and taking into account the capabilities of the system and measurement needs. An important advantage of the measurement using the gears multipurpose measuring software is that it is possible to measure any geometry of the wheels in relation to the CAD model. Using this measurement strategy avoids the need to purchase additional software, the measuring machine and its setup. You should only choose a method of analysis that will be carried out directly in the environment-measuring machine, or will be made in the CAD system based on the geometry acquired during the measurement with respect to the virtual model. In the second case, export is needed in the appropriate format measurement data to CAD software.

The influence of contour number on load carrying capacity of gears in aircraft gearbox demonstrator made by MEM

The paper presents an outcome of load carrying tests of gears in an aircraft gearbox demonstrator made of ABS B601polymer by means of INSPIRE D290 device. These tests checked an influence of an additional number of contours in gear models on durability of cooperating wheel pair during stand tests. The CAD models of the gears for stand tests were made in Autodesk Inventor program and were used as a base for making physical models. Therefore, Inventor files were exported to STL format. The following stage of data preparation was made in Model Wizard. The gears for stand tests were made by means of MEM method on INSPIRE D290 printer. Unlike most devices, this printer makes it possible to control not only the density of the filling in a model, but also to increase the number of contours. ABS polymer was chosen to make the gears. The choice was due to its good properties and because it is commonly used and also because it was possible to make the parts of the gearing at the Rzeszow University of Technology. Subsequently the gear pair was fixed on a test stand. The stand was designed in an open system. It was powered by a three-phase 0.75 kW electric motor. The control was provided by a single-phase inverter. Load on the stand was provided by an electromagnetic powder brake. This paper is a part of implementation of the research task number 4 „Development of a new, simpler and cheaper toothed gear in place of complicated and expensive planetary gears” of the project „Modern material technologies in aerospace industry.”