Wyniki wyszukiwania - BazTech

1

Surface roughness of aircraft engine blade models produced with various methods of rapid prototyping

Budzik G.

Journal of KONES

|

2007

|

Vol. 14, No. 2

55-60

EN

Results of the study of surface roughness of the aircraft engine blade model, produced with various methods of rapid prototyping are presented. Blade models were made with two incremental methods of rapid prototyping: stereo lithography (SLA-250 device) and three-dimensional printing (Z510 Spectrum printer). In incremental methods of rapid prototyping a model is formed by hardening of consecutive layers of the base material. Model position in the equipment work area has a significant influence on surfaces quality of a prototype, especially in stereo lithography method. It is essential in case of elements with curvilinear surfaces like aircraft engine blades. A CAD blade has been exported to the STL format within surface precision of 0,001 mm. Afterwards, it was duplicated and set up in various positions of the virtual work area of the 3D Light year programme dedicated to the SLA-250 device. Data prepared in this way have been used for producing physical models. Roughness surveys were carried out with the Talyscan150 device, manufactured by Taylor Hobson Precision. The measurements permitted making three-dimensional maps of surfaces of blade prototypes. Thanks to that, it was possible to determine optimum position of blade in the work area of RP devices in respect to prototype surface quality.

2

Prototyping of bevel gears of aircraft power transmission

Budzik G., Markowski T., Sobolak M.

Journal of KONES

|

2007

|

Vol. 14, No. 2

61-66

PL

Artykuł przedstawia proces wykonania prototypu stożkowej przekładni napędu lotniczego. Szybkie wykonywanie prototypów przekładni o nietypowych zarysach zębów jest możliwe metodami "Rapid Prototyping". Jedną z najdokładniejszych metod szybkiego prototypowania jest stereolitografia, która polega na warstwowym utwardzaniu promieniem lasera fotopolimeru. Metoda ta pozwala zbudowanie modeli kół zębatych o dowolnych kształtach. Za pomocą urządzenia stereolitograficznego SLA-250 wykonane zostały modele kół zębatych przekładni stożkowej. Modele stereolitograficzne mogą służyć do wykonania odlewów. Istotną zaletą prototypów kół zębatych wykonanych z fotoutwardzalnej żywicy jest ich przezroczystość. Zaleta ta pozwala na obserwację chwilowego śladu styku kół zębatych przekładni. Chwilowy ślad styku jest jednym z podstawowych parametrów opisujących prawidłową pracę przekładni. W tym celu przygotowane zostały specjalne modele kół zębatych o zmniejszonej grubości ścianki. Taka budowa pozwoliła na bardziej precyzyjną obserwację śladu styku oraz na zmniejszenia kosztów wykonania modeli. Śledzenie dynamiczne chwilowego śladu styku jest niemożliwe do wykonania tradycyjnymi metodami badawczymi. Zastosowanie metod szybkiego prototypowania daje dobre rezultaty w procesie badań nowych prototypowych przekładni zębatych napędów lotniczych.

EN

The article presents manufacturing process of bevel gears of aircraft power transmission. Rapid prototyping of gears with complex tooth forms is possible with the use of modern methods. One of such methods is the stereo-lithography, where a model is obtained as a result of resin curing with laser beam. This method allows creating gear model with arbitrary tooth form. Bevel gears was carried out by method of stereolitography on SLA 250 apparatus. Gear wheel prototypes were predestined for casting by method losing patterns. One of the best advantages of stereolitography model is its transparency. This advantage allow to observation instantaneous contact ellipses of gear. Instantaneous contact ellipses of gear is one of the most important parameters describe correctly work of gear. Research of instantaneous contact ellipses of gear requires special construction of model gear with thin wall. This construction allows costing reduction of prototype. Observation of instantaneous contact ellipses of gear is not possible by traditional research method. Rapid Prototyping method give good results in research process of new prototype of aircraft transmission gear.

3

Possibilities of using vacuum casting process for manufacturing cast models of turbocharger impellers

Budzik G.

Journal of KONES

|

2007

|

Vol. 14, No. 3

125-130

EN

Possibilities of producing cast models of turbocompressor impellers in silicon matrices by vacuum casting process are presented. Vacuum casting process enables producing cast models of impellers for precision casting. A standard model for silicon matrix making is a prototype produced with stereo lithography technique. The advantage of stereo lithographic model is its easy machinability that enables higher quality of impeller model surface. Silicon matrices enable casting of prototype models from foundry plastics, such as: casting wax, polyurethanes, polyester and epoxy resins. Properties of the plastic material used determine the shape of die parting. Because of its low strength, casting wax enforces die parting into a larger number of elements, thus enabling to pull it out without damage. The prototypes made from casting resins require considerably fewer parting surfaces. Silicon matrices enable to manufacture from several to several dozen cast patterns of prototype turbocharger impellers. The basic advantage of vacuum casting process is the shortening of prototype making time and cost, compared to traditional methods. The silicon matrixes permit casting and low-pressure injections of plastics. Some plastics may be used for producing foundry patterns for various metal alloy casting processes.

4

Possibilities of utilizing 3DP technology for foundry mould making

Budzik G.

Archives of Foundry Engineering

|

2007

|

Vol. 7, iss. 2

65-68

EN

Possibilities of application of three-dimensional printing (3DP) technology for making casting prototypes are discussed. Three-dimensional printing enables making of foundry moulds for elements of complex shapes. The mould presented in the paper was printed with the use of Z510 Spectrum unit in the Car Technology Sp. z o.o. (Ltd. Co.) in Kraków. The basic material for printing foundry moulds is the ZCast 501 powder. This powder is a mixture of traditional molding sand, gypsum and supplementary ingredients. The mould is made in ZCast technology, and it enables casting of zinc, magnesium and aluminum alloys at max. pouring temperature of 1100°C. The paper describes research on the possibility to utilize a standard ZP14 powder for building a rotor blade casting moulds. The research has showed that the ZP14 powder may serve for printing foundry moulds, which should then be subjected to thermo-chemical treatment. Application of the basic ZPrint system powder permits a reduction in mould manufacturing costs.

5

Hybrid foundry patterns of bevel gears

Budzik G., Markowski T., Sobolak M.

Archives of Foundry Engineering

|

2007

|

Vol. 7, iss. 1

131-134

EN

Possibilities of making hybrid foundry patterns of bevel gears for investment casting process are presented. Rapid prototyping of gears with complex tooth forms is possible with the use of modern methods. One of such methods is the stereo-lithography, where a pattern is obtained as a result of resin curing with laser beam. Patterns of that type are applicable in precision casting. Removing of stereo-lithographic pattern from foundry mould requires use of high temperatures. Resin burning would generate significant amounts of harmful gases. In case of a solid stereo-lithographic pattern, the pressure created during gas burning may cause the mould to crack. A gas volume reduction may be achieved by using patterns of honeycomb structure. However, this technique causes a significant worsening of accuracy of stereo-lithographic patterns in respect of their dimensions and shape. In cooperation with WSK PZL Rzeszów, the Machine Design Department of Rzeszow University of Technology carried out research on the design of hybrid stereo-lithographic patterns. Hybrid pattern consists of a section made by stereo-lithographic process and a section made of casting wax. The latter material is used for stereo-lithographic pattern filling and for mould gating system. The hybrid pattern process consists of two stages: wax melting and then the burn-out of stereolithographic pattern. Use of hybrid patterns reduces the costs of production of stereolithographic patterns. High dimensional accuracy remains preserved in this process.