New approach for recycling spare parts, components and assemblies

Recycling and disposal are one of the most complicated topics in the lifecycle of a mechanism, especially in case of previous generations of machines that were designed without taking any care of post exploitation period. In the current work, the ‘feasibility points’ of recycling units, methods of recycling as well as pricing formation for recycling materials, reviewed and proposed by several world universities and scientific bureaus and applied by major world brands have been analysed. The general principles that should be rated as a basis when designing and creating new mechanisms, as well as the actions which we consider as a necessary supplement to the existing rules of the lifecycle of assemblies and which should be applied in practice, were introduced by authors in the ‘Management of parts and components for units and assemblies in mechanical engineering industry and its impact on the environment’. It was discovered that even modern assemblies, not to mention previous generations, are being designed without taking into consideration any possibilities of easy recycling the used materials. The number of components of mechanisms, which are being repaired as assemblies, is continuously increasing, while maintainability and repairability of separate parts is decreasing. Taking into account the state of the art in the field, the new approach for promoting the reusing natural resources and decreasing the harmful effects of obsolete components of mechanisms on the environment is proposed. Thus, using the fast-moving parts that in post operational period can be easily detailed by type of a material will ensure more efficient consumption of natural resources. Our research and developments significantly reduce the costs of recycling and these materials become competitive comparing to the new ones. Taking into account the state of the art in the field, the new approach for promoting the reusing natural resources and decreasing the harmful effects of obsolete components of mechanisms on the environment is proposed

Šķidruma plūsmas rotorsūkņu rotoru virsmas fizikāli mehānisko īpašību uzlabošanas metožu analīze

Pieaugot ražošanas apjomiem un prasībām pēc drošākiem darba apstākļiem – ne tikai mašīnbūvē, dažāda veida transportā, bet arī citās ražošanas sfērās aizvien biežāk sāk izmantot saspiestā gaisa iekārtas. Vieni no tiem ir skrūves tipa kompresori. Skrūves tipa kompresori ir vienkārša dizaina rotoru, pozitīva pārvietojuma mašīnas, kas var darboties ar augstu efektivitāti pie salīdzinoši augstiem rotācijas ātrumiem plaša spiedienu diapazonā. Kompresora uzbūves pamatā ir divas vārpstas ar speciāli izveidotām spirāles veida rievām. Rotori ir pakļauti mainīgu spēku ietekmei, ko rada saspiestās gāzes, kā arī inerces spēki un griezes momenti. Prasības šiem rotoriem ir salīdzinoši augstas, to izgatavošanai ir jāizmanto materiāli, kas nodrošina teicamus statistiskos un dinamiskos mehāniskās pretestības rādītājus – izturību, cietību, plastiskumu, jābūt ar labu korozijnoturību, siltumnoturību, kā arī lielu nodilumizturību. Raksta mērķis ir pierādīt to, ka ne vienmēr rotoru izgatavošanā ir jāizmanto reglamentētie dārgie materiāli, bet var izmantot lētākus materiālus. Izmantojot mūsdienu tehnoloģijas varam iegūt materiālam tādas pašas īpašības kā reglamentētam. Raksta pamatā galvenā uzmanība ir pievērsta jaunu vai uzlabotu tehnoloģiju izstrādei, lai pilnveidotu zemākas kvalitātes tēraudus, kas garantētu materiālu, ko raksturotu aizvien labākas tehnoloģiskās un mehāniskās īpašības, piemērotība rotoru ražošanai. Sīkāk šajā darbā tiek analizēts tēraudu tehnoloģisko, mehānisko īpašību izmaiņas, izmantojot mehāniskās nocietināšanas, termiskās un termomehāniskās nocietināšanās apstrādes metodes, to priekšrocības un trūkumi, kā arī analizētas mehānisko īpašību izmaiņas, ja izmaina kristālu graudu formu. Zinot to, ka daudzi elementi, piemēram, ogleklis, slāpeklis un citi elementi, uzlabo materiāla virskārtas tehnoloģiskās un mehāniskās īpašības, darba gaitā sīkāk arī tiek analizēta ķīmiski termiskā iedarbe, kā arī īpašību izmaiņa izmantojot dažādus pārklājumus rotoriem. Darba ietvaros arī tiek analizētas biežāk izmantoto tehnoloģiju priekšrocības un trūkumi. Skrūves tipa kompresoru rotori ir vieni no kompresora atbildīgākām detaļām, no kurām ir atkarīga to darbības produktivitāte. Darba noslēgumā doti dažādi ieteikumi rotoru virsmas uzlabošanai

Usability of Analytical Methods in Design of Instrument Profile of Screw Type Compressors

A very important catch, not only in the engineering, but also in any industry of production of national economy in general, takes the use of compressed air. Enlargening of industrial production volumes, parallel asks for larger demand of compressed air, for getting them more frequently use technologically most fashionable, economic and the safest of compressors machines - including screw types compressors. Geometry of screw type compressor shaft isn’t evolvent type, whereof is dependent compressor action productivity. For creating screw type shaft profile there is necessity to make special designed instrument with which assistance are available reach right forms of profile contours. In the beginning of this article is provided instrument designing possibilities examination, what operates with knock dawn method. In foundation there are examined three possible of calculation methods of instrument profile type: graphical, analytical and graphical analytical method. Also provide analysis of these methods usability in modern production. At the second part of work is given an analytical calculation of disevolvent instrument profile type, conformable the type of rotors of screw type compressors. At the end of article conclusion is done usability analysis of profile designing methods

Analysis of Possibilities to Improve the Surface Physical Mechanical Properties of Rotors of Screw Type Pumps

More frequently rotor pumps and screw type compressors as kind of them are used as machines for production of compressed air. These compressors are operating with greater efficiency on high speeds of rotary rate, and operate in a wide range of pressures. The rotors of pump are inferior to influencing of variable forces and rotary moments which produce compressed gases. So, as the requirements for these rotors are comparing high, they should be made of quality materials, which provide excellent characteristics in statistical and dynamic pointers of mechanical resistance. In foundation of the article the main attention is paid to making of new or improved technologies, to perfect the properties of steels of lower quality, which will assure material, which always technological and mechanical dignities would characterize, adjusted for the production of rotors. The purpose of the work - to establish, that not always rotors should be made of regulated expensive materials, but it is possible to use cheaper materials. This work analyzes in more detail changes of steel technological, mechanical properties, using the mechanical strengthening, thermal and thermomechanical processing methods of strengthening, their advantages and failings. Knowing many elements, as for example, carbon, nitrogen and other elements which improve technological and mechanical properties of the overhead layer of material, in the work also the thermal influence is analized, and also the change of the properties of the surface using various coverages for rotors. At the end of the article the conclusion gives various advices for improvement of the surface of rotors

Inženierizstrāžu materiāli un apstrādājošie sakausējumi

Darbs ietver uzziņas par dažādu materiālu apstrādājošajiem augstleģētejiem, leģētajiem un nodilumizturīgajiem tēraudiem

Inovatīvi metāla griešanas instrumenti un tehnoloģijas

Pārskats par jaunākajām tendencēm metālu griešanas tehnoloģijā, nanoizmēra instrumenti, apstrādes režīmi, sagaidāmie apstrādes virsmas parametri