54 research outputs found
Rehabilitation of Cut-over Peatland on the Example of AS Nurme Turvas
No full textEesti soode pindala on vähenenud viimase 60 aasta jooksul ligikaudu 60%, mille on põhjustanud soode kasutamine põllumajandusmaana, metsanduses, infrastruktuuri arendamine, põlevkivi kaevandamine ja turbatööstus. Turba kaevandamine on sellest 8,5%. Enne 1950. aastat kaevandati turvast väikestes kogustes ja pätsidena raba servadest, mis jättis looduslikuks taimestumiseks head tingimused. Peale 1950. aastat võeti turbatootmises kasutusele freestehnoloogia, mille tulemusel rabad kuivendati, eemaldati taimestik ning rajati suured tasase pinnaga ja kraavivõrgustikuga turbaväljad. 2009. aastal läbi viidud uuringu põhjal on Eestis 9371 ha jääksoosid ning praeguseks hetkeks arvatakse olevat juba kahekordne. Jääksoodega kaasnevad mitmed olulised keskkonna probleemid nagu lagugaaside eraldumine, suur tuleohtlikkus, mõju naabruskonna veerežiimile. AS Nurme Turvasel on ette nähtud ammendunud freesväljade taastamine metsastamise näol. Selleks on ettevõtte loonud rekultiveerimisfondi, kuhu raha iga aastaselt eraldatakse. Ettevõtte juhtkond on veendunud, et neile määratud taastamisviis antud tingimustes pole sobiv. Töö koostamise käigus tutvuti Eestis varasemalt kasutatud taastamisviisidega, neid alalüüsides ning märkides üle tingimused, mis peavad olema täidetud, et oleks võimalik tagada parim tulemus nii keskkonnale kui ettevõtjale. Töö käigus peeti nõu spetsialistidega ning varasemalt teemaga kokku puutunud inimestega. Autor leiab, et metsastamine ei sobi analüüsitud alale peamiselt selle tõttu, et kolmandikust suvest puhub rabaväljadel ligi 12-20 m/s tuul. Jääksoodesse soovitatakse peamiselt istutada kaskesid, mändisid ning kuuski, mis on aga kõige tormihellemad puuliigid, seetõttu oleks antud rabaväljadel nende liikide kasvama jäämine raskendatud. Autori hinnangul on üheks parimaks võimalikuks lahenduseks jääksoo taastamisel AS Nurme Turvase territooriumil marjakasvatuse rajamine. Kraavivõrgustikuga aladel on võimalik muuta veerežiimi marjakasvatuse jaoks sobilikuks. Samuti ei sega marjakasvatus kaevandustegevust ümberkaudsetel rabaväljadel. Tegemist oleks taastamisviisiga, mille õnnestumise tõenäosus on kõige suuremThe surface area of Estonian peatland has decreased by nearly 60% over the past 60 years, caused by the use of peatlands in agriculture, forestry, infrastructure development, oil shale extraction, and peat industry. Peat extraction makes up about 8.5% of this. Before 1950, peat was extracted in small quantities, and as cakes around the edges of the peatland, which ensured good conditions for natural vegetation. After 1950, the milling method was introduced in peat production. As a result, peatlands were drained, vegetation was removed, and large and flat peat fields with networks of dikes were established. According to a study from 2009, there is 9,371 ha of cut-over peatland. Presently, this number is believed to be 20,000 ha. Cut-over peatland is accompanied by a number of significant environmental issues such as degradation gases, high flammability, and impact on the hydrological regime of the neighbourhood. Attempts to restore cut-over peatlands have been made across the world as well as Estonia. While there have been attempts to restore milled peatlands for recreational and economic objectives in Estonia, a common understanding and good practice do not yet excist, and restoration of peatland using a prescribed method is required from businesses that have leased land for mining from the state and acquired a mining licence. This is done without ensuring that the method is suitable in the first place. Objectives of the thesis: • To describe the environmental problems related to cut-over peatland. • To investigate which methods of rehabilitation have been used for cut-over peatland in the past, and highlight their pros and cons as well as the conditions for their functioning. • To analyse the intended rehabilitation methods of AS Nurme Turvas and suggest the most suitable method. AS Nurme Turvas is expected restore the milled fields by afforestation. To do this, the company has created a land restoration fund, into which money is allocated each year. The management of the company is convinced that the intended rehabilitation method is not suitable for the present conditions. During the course of preparing the theses, previously used restoration methods were examined and analysed, highlighting the conditions that have to be met in order to ensure the best results for both the environment and the company. Specialists and individuals with prior contact with cut-over peatland were consulted. The author finds that afforestation is not suitable there due to the fact that for one third of the summer, winds of nearly 12l–20 m/s blow on the peatlands. Mainly birches, pines and spruces are suggested for planting on cut-over peatlands. These tree species are also most sensitive to storms and their growth on the peatlands would be difficult due to strong and consistent winds. As one of the best possible solution for restoring cut-over peatland on the territory of AS Nurme Turvas, the author suggests the introduction of berry cultivation. It is easy to convert hydrological regimes on areas with networks of dikes to be suitable for berry cultivation. Additionally, growing berries does not interfere with the mining activities on the surrounding peatlands. In conclusion, it can be said that it would be a method of restoration with the highest probability of success
LC-MS analüüsimetoodika arendamine põletikuvastaste ainete määramiseks loomsetes maatriksites
No full textTöö eesmärk oli töötada välja madalate avastamispiiridega ja selektiivne LC-MS metoodika
põletikuvastaste ainete jääkide määramiseks loomsetes maatriksites. Uuritavateks ühenditeks
olid ibuprofeen, ketoprofeen, fluniksiin, firokoksiib, meloksikaam, karprofeen ja atsetaminofeen.
Analüütide lahutamiseks kasutati pöördfaasvedelikkromatograafiat ja eluentidena metanooli ning
heksafluoroisopropanooli baasil puhverlahust. Analüütide detekteerimiseks kasutati kolmekordse
kvadrupooliga massispektromeetrit mitme ülemineku jälgimise režiimis. QuEChERS
prooviettevalmistusmetoodika arendamisel kasutati kanamaksa proove. Töö raames saavutati
uuritud seitsme analüüdi jaoks optimaalsed kromatograafilise lahutuse ja tundliku
massispektromeetrilise detekteerimise tingimused. Proovidest analüütide määramise saagised
jäid vahemikku 53-78%
LC-MS analüüsimetoodika arendamine ja valideerimine ravimijääkide määramiseks linnumaksast
No full textTöö käigus arendati QuEChERS-i multimeetodil põhinev LC-MS metoodika kuue
mittesteroidse põletikuvastase ravimi, nimelt ibuprofeeni, ketoprofeeni, fluniksiini,
firokoksiibi, meloksikaami, karprofeeni, ning atsetaminofeeni määramiseks linnumaksast.
Lõppeesmärgiks oli analüüsida neid aineid röövlindude maksadest ning hinnata, kas arendatud
metoodikaga oleks võimalik uurida ravimireostuse ulatust. Valideerimine viidi läbi vastavalt
Euroopa Ravimiameti valideerimisjuhendile, kasutades ValChrom-i tarkvara, millega hinnati
metoodika määramispiire, selektiivsust, lineaarsust, korduvust, laborisisest korratavust ja
tõesust. Analüüsiti kümne kanakulli maksasid, kusjuures kolme linnu proovist tuvastati
meloksikaami (kontsentratsioonid 2,1 ng/g, 0,49 μg/g ja alla määramispiiri), mida oli Eesti
Maaülikoolis kasutatud lindude ravimiseks
Defining the base configuration for the THeMIS
No full textKäesolevas lõputöös uuris autor võimalust määratlemaks ettevõtte Milrem AS toote THeMIS baaskonfiguratsiooni. Autor seadis lõputöö eesmärgiks määratleda THeMIS’le uus baaskonfiguratsioon, mis võtaks arvesse ka müügikonfiguratsiooni mooduleid ja hõlmaks endas juba viimaste paigalduseks vajaminevaid detaile mis tuleb paigaldada varajastes koostamise etappides. Tehes seda saavutamaks kulude kokkuhoidu tootmises ja pakkudes hilisemalt kliendile mugavamat võimalust oma soetatud sõidukit modifitseerida lisamoodulitega.
Püstitatud eesmärgi lahendamiseks seadis autor paika mitme etapilise protsessi. Esimeses etapis uuris autor teema kohast kirjandust ja leidis peamised murekohad millele peab tähelepanu pöörama, lahendamaks antud uurimisprobleemi. Järgmise sammuna kaardistas autor ära hetkel olukorra, nii baaskonfiguratsiooni kui ka müügikonfiguratsiooni moodulid. Selle tarbeks kogus autor informatsiooni ettevõtte ERP süsteemist, teostas vaatlusi tootmises ja toetava tegevusena arutas ka antud probleemi tootmisjuhiga, kes suunas autorit ettevõtte siseselt õigete infoallikateni. Antud tegevuse tulemusena põhistas autor uurimisprobleemi. Selle tulemusena tekkis autoril ülevaade hetke olukorrast mille alusel oli võimalik teostada edasist analüüsi leidmaks neid müügikonfiguratsiooni detaile mida oleks mõislik lisada baaskonfiguratsiooni. Viimase etapina teostas autor majandusanalüüsi pakutud lahendustele müügikonfiguratsiooni mooduli kaupa. Lõputöö raames püstitatud uurimisküsimustele leidis autor kõigile vastuse.
Tulemusena pakkus autor välja kaks võimaliku lahendust, primaarne lahendus ja sekundaarne lahendus. Primaarne lahendus oleks järk järguline üleminek uuendatud baaskonfiguratsioonile müügikonfiguratsiooni moodulite kaupa, võttes arvesse müüdavate lisamoodulite mahtu. Kohene täielik baaskonfiguratsiooni muudatus oleks ettevõtte tootmisele majanduslikult kahjulik. Sekundaarne lahendus oleks olemasoleva disaini ülevaatamine, läbi mille oleks võimalik toote omahinda vähendada ja seeläbi parendada ka tasuvuspunkti.
Autor hindab oma lõputöö tulemusi ja järeldusi heaks. Plaani teostatavus kahjuks ei ole kohene, aga pikema ajaperioodi jooksul kindlasti tasuv. Antud muudatused vähendaksid töökoormust ettevõtte siseselt, muudaksid paindlikumaks järelteeninduse ja looksid ettevõttest Milrem AS ka parema kuvandi kliendi silmis. Antud lõputöö võimaldab edasiseid uuringuid ka tulevikus, täpsemalt autori välja pakutud sekundaarse lahenduse suunal.In this thesis, the author explored the possibility of defining the base configuration of the product THeMIS of the company Milrem AS. The author set the goal of the thesis to define a new base configuration for the THeMIS, which would also take into account the sales configuration modules and include the components required for their installation during the early stages of assembly.". The aim was to achieve cost savings in production and to offer the customer a more convenient way to modify their purchased vehicle with additional modules at a later stage.
To achieve this goal, the author established a multi-step process. In the first stage, the author reviewed relevant literature and identified the main issues that needed to be addressed to solve the research problem. The next step was to map the current situation, including both the base configuration and the sales configuration modules. For this purpose, the author gathered information from the company's ERP system, conducted observations in production, and, as a supporting activity, discussed the issue with the production manager, who directed the author to the appropriate internal sources of information. As a result of this activity, the author substantiated the research problem. This led to an overview of the current situation, which served as a basis for further analysis to identify those sales configuration components that would be reasonable to include in the base configuration. As the final step, the author carried out an economic analysis of the proposed solutions for each sales configuration module. The author was able to answer all the research questions posed in the thesis.
As a result, the author proposed two possible solutions: a primary solution and a secondary solution. The primary solution would be a gradual transition to an updated base configuration, module by module, based on the volume of additional modules sold. An immediate and complete change to the base configuration would be economically harmful to the company's production. The secondary solution would be to review the existing design, which could potentially lower the product’s cost price and thereby reduce the break-even point.
The author considers the results and conclusions of the thesis to be good. Unfortunately, the feasibility of the plan is not immediate, but over a longer period, it would certainly be profitable. These changes would reduce the internal workload of the company, make after-sales service more flexible, and improve the public image of Milrem AS in the eyes of customers. This thesis also enables further research in the future, particularly in the direction of the secondary solution proposed by the author
5S system application at Printcenter Eesti AS aftertreatment department
No full textPrintcenter Eesti AS on trükiteenuseid pakkuv ettevõte. Alustades alla kümne töötajaga on ettevõte kasvanud saja töötajani. Ettevõtte toodang on väga lai ja on võimeline valmistama erinevaid trükitooteid erinevatele materjalidele. Konkurentsieelise turul tagab lai tootevalik ning suurepärane tehnoloogiline masinapark. Kuid suurepärane tehnoloogiline masinapark ja lai tootevalik pole saavutanud ettevõtte tööjõu tootlikkuse suurenemist 10% võrra. Autor otsustas kasutada laialdaselt kasutust leidnud 5S meetodit antud ettevõttes, mis aitab tõsta tootmisefektiivust. Esmane eesmärk on luua puhas ja korrektne töökeskkond, kus kõikidel asjadel on oma kindel koht. 5S meetod koosneb viiest etapist: S1 – sorteeri, S2 – säti korda, S3 – särama, S4 – standardiseeri ja S5 säilita. 5S meetodi rakendamisel tuleb alustada esimesest etapist. Autori jälgimine Printcenteri järeltöötluse osakonnas näitas selgelt, et osakonnas valitseb “kaos”, mida on näha ka Sele 4 – Sele 11 pealt. Järgnevalt on autor etapp haaval teinud soovitusi 5S põhjal, mida saaks teha paremini antud osakonnas. Põhiline probleem ongi ebavajalike tarvikute või tootmisjääkide kuhjumine kohtadesse, mis ei ole sobilikud ning takistavad efektiivset tootlikust. Iga etapi lõpus on välja toodud protokoll eesmärkidega ja ettepanekutega, mis aitaks eesmärke saavutada. 5S ainuüksi ei aita tõsta tootmisefektiivust vaid aitab ka tagada tööohutuse, erinevate töövahendite õige hooldamise ja kasutamise. Just tänu 5S-i rakendamise käigus tulevad välja väärtust mitte omavad tegevused, mis aitavad kehtestada selged kontuurid ja distsipliini, et jätkata teiste kulupõhiste tootmiste projektidega. Lõputöö käigus toodi välja ettevõtte erinevad murepunktid põhinedes 5S-le, samuti tehti ka ettepanekuid töö hõlbustamiseks. Autor koostas professor Milvi Tepi audifaili põhjal kokkuvõtte töömotivatsioonist, mis on suunatud osakonnajuhtidele ja personalijuhtidele, et kuidas mõista paremini oma alluvaid. Oluline on kaasata ka töötajaid ja neid hoida piisavalt motiveeritutena.Printcenter Estonia AS is printing service company. Starting with under ten workers and with years growing up to hundred employees. The company´s product selection is vast and capable of producing different printing products for a variety of different materials. Advantage over its competitors comes from a wide range of products and excellent machinery. But not even the machine park and an extensive product selection, has not increased the company´s productivity by 10%. Author decided to use 5S method, which is a widely-used method that will help improve the efficiency of production. The primary objective is to create a clean and orderly environment where everything has its own place. The 5S method consists of five stages: S1 – Sort, S2 – Set in Order, S3 – Shine, S4 – Standardise and S5 – Sustain. Implementation of the 5S method starts from the first stage. Author´s observation in Printcenter post processing department clearly showed that the department was in „chaos that can also be seen on the Sele 4 – Sele 11. Author made step by step suggestions based on 5S methodology, what could be done better in given department. The main problems are the unnecessary accessories and accumulation of production residues in places that are not useful in any way and impede the effectiveness of productivity. At the end of each phase there is given a protocol with objectives and suggestions, that will help reach the objectives. Implementation of 5S will not only raise production efficiency but also helps ensure work safety of using various tools in proper manner and their correct maintenance. Because of 5S implementation, activities that hold no real value will show. That will help to establish clear contours and disciplines to pursue other cost–oriented production projects. In the thesis, various points of concern where pointed out based on 5S, also to facilitate work author gives proposals for the company. Based on Professor Milvi Tepp´s audio file author compiled a summary about work motivation, which is aimed to the department managers and human resource managers to get a better understanding of their employees. It is important to involve employees and keep them motivated
Põhiseadus kui süsteem
No full textVäitekirja eesmärk on kinnitada ideed, et põhiseadus on süsteem, ja tuua esile süsteemse lähenemise eelised. Autor leiab, et iga uus kriitiline käsitlus võib heita valgust mõnele põhiseadusliku süsteemi väärtuslikule seosele ja aidata laiendada olemasolevate argumentide ringi. Sissejuhatavas artiklis analüüsib autor kahte põhimõistet – põhiseaduse ja süsteemi mõistet. Esimeses peatükis kaitseb autor põhiseaduse süsteemsuse keskseid teoreetilisi aluseid. Järgnevates peatükkides näitab autor, et idee põhiseadusest kui süsteemist võimaldab meil jõuda põhiseaduse konsistentse ja koherentse dogmaatikani ning leida seeläbi paremaid lahendusi praktilistele põhiseaduslikele juhtumitele.The aim of the thesis is to confirm the idea that the constitution is a system and to demonstrate the advantages of the systematic approach. The author considers that every new critical approach might bring a new valuable connection of the constitutional system to light and help to broaden the scope of available arguments. In the introductory article the author analyses two fundamental concepts – the concept of constitution and the concept of system. In the first chapter the author will defend central theoretical foundations of the systematicity of the constitution. In the following chapters the author demonstrates that the idea of the constitution being a system enables us to achieve consistent and coherent doctrine of constitutional law and therefore better solutions for practical constitutional cases.https://www.ester.ee/record=b526929
The Organisation of Construction Works at Jaama 8
No full textKäesoleva lõputöö ülesandeks oli lahendada Jaama tn 8 ehitustööde organiseerimise projekt, mille võib lugeda täidetuks. Seletuskirjas on antud rajatava hoone arhitektuurse ja konstruktiivse lahendi kohta piisav ülevaade ning koostatud on ehitustööde lühike kirjeldus Ehitusplatsi üldplaani koostamisel on välja toodud planeeritav soojakute paiknemine, tõstemehhanismide paiknemine, ajutised teed ja platsid, objekti ressurssidega varustamine ning materjalide ladustamisala. Lisaks on tehtud peamised ressursside arvutused. Määratud on ehitusaegne veevajadus ning vastavalt sellele dimensioneeritud ajutine veetorustik. Lõputöö majandusosas on koostatud ehitustööde mahutabel koos tööde maksumustega ning määranud töölisbrigaadide koosseisud ja tööde kestused. Tabeli alusel on koostatud kalendergraafik tööjõuvajadusega. Lõputöö raames on autor lahendanud kaks tehnoloogiakaarti, mis hõlmavad 2. korruse trepielemendi ja vahelae montaažitöid ning katuse- ja fassaaditöid. Kõnealuseid tööprotsesse on detailselt kirjeldatud ning loetletud on tööde kvaliteedinõuded. Käesoleva lõputöö koostamine oli autori jaoks täies ulatuses akadeemiline ning autor ei ole vaadeldava ehitusobjektiga muul viisil seotud. Sellest hoolimata andis lõputöö koostamine autorile uusi teoreetilisi teadmisi ning aitas mõista ehituse organiseerimise projekti koostamise tegelikku vajalikkust.The aim of this final paper was to draft a comprehensive management plan of the works related to the construction of Jaama 8 residential building consisting of nine apartments and two commercial premises. For this purpose the author analyses and provides solutions for the methods and techniques used at the specific building site. The paper is based on both the architectural as well as constructional project. In this paper the author gives an overview of the structural specifications and technical characteristics of the residential building. In addition, the author describes the architectural solution and characterises the main constructional elements of the building. A short description is given of all the stages of the construction process from the preparation works to the actual handover of the completed object. A separate chapter is devoted to the construction site layout planning. In this chapter the logic of such planning is described. It provides a detailed overview of the planned location of heated shelters, the location of lifting mechanisms, the organisation of temporary access roads and areas, the provision of resources to the site and the location of material storage area. The chapter is supported by a drawing in the graphic part of the paper. In this chapter the author also presents the calculations of the main resources. The water requirement at the construction site is determined and temporary plumbing is dimensioned. Additionally, the site’s power requirements are determined by calculating the maximum electricity consumption needs of the construction period on the basis of the work schedule. In the economic part of the paper the author presents a construction work volume table together with the indication of costs. The same table also contains the number of construction workers and the duration of different works. The cost and duration of construction works are calculated by employing the unit prices and time norms elaborated by Eke Nora OÜ. Following this method the net cost of the construction works is budgeted at 864849,9 euros. The table has also provided a basis for preparation of the work schedule presented in the graphic part of the paper. One of the most substantial and important parts of the final paper was the drawing up of the technology cards for the 2nd floor staircase element and ceiling slab assembly as well as the roofing and facade works. The explanatory text includes a detailed description of the related work processes and enlists the quality requirements. The preparation of the technology cards revealed parameters on the basis of which necessary lifting mechanisms were chosen for the construction works to be carried out. The explanatory part of the technology cards is supported by the drawings in the graphic part. The present paper is fully academic by nature and the author is not in any other way connected with the discussed building. Nevertheless, the writing of this paper has given the author new theoretical knowledge and has helped him better understand the real need for the preparation of a construction management project
Competition Motorcycle Gearbox Analysis
No full textLõputöö eesmärgiks oli teada saada millist materjali on kasutatud hammasrataste valmistamiseks.
Milliseid termotöötlus protsesse on kasutatud. Mõista miks hammasrattad purunevad. Mida peaks
hammasrataste juures muutma et neid edaspidi usaldada saaks ning need ei puruneks nii tihedalt.
Kõik need küsimused leidsid vastused. Materjaliks on 18 CrNiMo 7-6. See leiti tänu materjali
keemilise koostise määramisele. Sealt saadud andmete põhjal otsiti sobivaim materjal. Teades et seda
materjali kasutatakse tihedalt Saksamaal hammasrataste valmistamiseks ning uuritavad
hammasrattad on valmistatud samuti Saksamaal võib kindlalt väita et materjal on õigesti leitud.
Teiseks eesmärgiks oli teada saada millist termotöötlus protsessi on kasutatud. Tehase toe
puudumisele tuli see leida töö käigus. Madala süsiniku sisalduse tõttu ei ole materjal karastatav.
Sellepärast on tehtud sellele tsementiitimine. Selle käigus on pind rikastatud süsinikuga ning seejärel
tehtud pind karastamine. Sellele viitavad ka materjali kõvadused pinnalt ning seest. Hammasrataste
sisu on pehme ning väliselt kõvad. Sisemine kõvadus on 39 HRCd ning pinnalt 55 HRCd.
Kolmandaks eesmärgiks oli teada saada miks hammasrattad purunevad. Sellele vastuseks on liiga
kõvad kõvadused hammasratta pinnale. Soovituslik maksimaalne kõvadus pindkarastusel on 50
HRCd aga mõõdetud tulemused näitavad keskmiseks tulemuseks 55 HRCd. Maksimaalne kõvadus
mõõtmisel tuli 57 HRCd. See on seitse ühikut üle soovitatud normi. Materjali kõrgemal kõvadusel
on materjal hapram ning murdub lihtsamini.
Samuti tekitas probleeme hammasratastele rakenduv jõud. Hammasrattad ei pidanud sellele jõule
vastu. Seda kinnitas hammasratastele tehtud analüüs Solid Edges. Sellele leiti kaks lahendust.
Esimese variandina muudeti hammasrattaid 8 mm laiemaks. Selle muutuse tulemusena peavad
hammasrattad sellele pingele vastu. Teise variandina muudeti hammasratta materjali. Kasutati 18
CrNiMo 7-6, aga pakutav materjal mis arvutuste kohaselt peab vastu on Uddeholm Bure.
Kokkuvõtteks võib öelda et kõik eesmärgid, mis püstitati ka lahendati. Töö arendas autori nägemust
kuidas hammasrattad ning käigukast toimib.The topic of this research is "Analysis of the Gearbox of a Competition Motorcycle." The thesis
became the author's problem while using the Zabel engine. During the period 2015-2021, the author
was engaged in motocross, more precisely in a motorcycle with a sidecar. During this period, the
gears of the gearbox broke very often. During the season, which lasted from May to September, the
gearwheels had to be changed five to six times. There are 18 to 22 races per season plus pre-season
and in-season training. During that duration, you get 80 to 100 hours of driving. The main concern
was the third gear. This gear is the most used and because of that, it broke the most.
The gears do not wear out, do not overrun, or anything like that. The whole tooth breaks off from the
gearwheel. 99% of the time the broken tooth comes from the third gear. There have been instances
where other gears have broken, but these are very rare. The service life of gears varies greatly. The
author has managed to drive half of the season with one pair of gears. It's about 10 races or 20 hours.
The least used gear was used for one race, which lasted 20 minutes plus two laps. Thus, it is not
possible to predict how long a pair of gears can be used. As a result, breakage cannot be prevented.
Usually, it is not possible to finish the race with broken gear. This means you do not finish the race
and won't score any points.
The cost of one third gear pair is 300 €. It takes 1500 to 1800 € per season. This is a bargain for a
budget. The author's strong driving style or gear changes are not the cause of the breakage. Also, the
frequency of breakage is not changed by changing the gearbox oil brand. In an interview, four-time
world champion Etienne Bax said he changes third gear gears after each race. In the World
Championship stage, one race lasts 30 minutes plus two laps. So he exchanges them more than the
author.
Without the support of the factory, I would like to know more about the materials, processing, and
required quality of the gears. The thesis aims to find out what material has been used to make the
gears. What heat treatment processes have been used. Understand why gears break. What should be
changed about the gears so that they can be trusted in the future and they will not break so easily.
Suggest solutions for changes.
During the research, all these questions were answered. The material is 18 CrNiMo 7-6. This was due
to the chemical composition of the material. Based on the data obtained there, the most suitable
material was searched. Knowing that this material is widely used in Germany for the production of
32
gears and that the gears under investigation are also manufactured in Germany, it can be stated with
certainty that the material has been correctly found.
The second goal was to find out what heat treatment process was used. The lack of factory support
meant that this had to be found during the work. Due to its low carbon content, the material is not
hardenable. That is why it has been cemented. In the process, the surface is enriched with carbon and
then the case is hardened. This is also indicated by the hardness of the material on the surface and
inside. The gears are softer inside and hard on the outside. The internal hardness is 39 HRC and the
surface is 55 HRC.
The third goal was to find out why the gears break. The answer is too hard hardness on the surface of
the gear. The recommended maximum hardness for case hardening is 50 HRCd, but the measured
results show an average result of 55 HRC. The maximum hardness measured was 57 HRC. This is
seven units above the recommended standard. With higher material hardness, the material is more
fragile and breaks more easily.
The force applied to the gears also caused problems. The gears could not withstand this force. This
was confirmed by the analysis of the gears in Solid Edge. To this problem, two solutions were found.
The first solution was found to make the gears 8 mm wider to withstand this tension. The second
solution is to change the material. Originally they are made of 18 CrNiMo 7-6 but the author thinks
that Uddeholm Bure would be a much more better choice. In conclusion, all the goals that were set
were solved. The work developed the author's vision of how gears and gearboxes work
Measuring System, Control and Necessity of Elektrilevi OÜ 0,4 kV Current Transformers
No full textBakalaureusetöö
Tehnika ja tehnoloogia õppekavalElektrilevi OÜ on oma süsteemis kasutanud juba pikka aega bilansi mõõtesüsteeme. Dokumente selle tööliigi teostamiseks on paigaldise omanikul väga palju. Nende erinevate dokumentide vahel on väga keeruline algajal navigeerida.
Eesmärgiks on võrrelda erinevate Elektrilevi OÜ 0,4 kV paigaldistes kasutatavaid bilansi mõõtesüsteemide paigaldust mast alajaamadesse. Samuti püüab autor selgitada mõõtesüsteemidele tehtavat kontrolli ja selle vajalikkust. Lisaks oli ka eesmärgiks uurida erinevaid mõõtesüsteemide kontrolli viise ja tuua välja põhilised puudused süsteemide ehitamisel ning kontrollimisel. Töös on kasutatud Empower AS-ile kuuluvaid mõõteseadmeid.
Mõõtesüsteemide ehitusel ei saa läheneda alati hinnast. Oluline on leida terviklahenduse käsitletavale probleemile. Isegi kui hinna vahe on väike, aga suudetakse luua parem süsteem AJ teenindamiseks, siis autori arvates võiks seda teha.Elektrilevi OÜ has used its balance sheet measuring systems for a long time. The owner of the installation has a large number of documents for this type of work. It's very difficult for novice users to navigate through these different documents. The aim is to compare the installation of balance metering systems used in 0,4 kV switchgears of various Elektrilevi OÜ in the substation. The author also attempts to clarify the control of measuring systems and its necessity. In addition, the aim was to examine the various ways in which measuring systems were monitored and to identify the main weaknesses in the construction and control of systems. In the construction of measuring systems, you can not always approach the price. It is important to think that the problem you want to solve is a complete solution. Even if the price gap is small, but a better system can be created to serve the AJ, the author believes that this could be done. The author wants to investigate the future of medium voltage measuring systems
- …
