Tribološko optimiranje aksialnih drsnih obročev za avtomobilske alternatorje

Poljanec, Dejan (avtor), Kalin, Mitjan (mentor)

Doktorsko delo obravnava vpliv obratovalnih parametrov (drsna hitrost, normalna kontaktna sila, električni tok in smer toka) na tribološke in električne lastnosti inovativne konstrukcije drsnega električnega kontakta. Namensko tribološko preizkuševališče, ki je tudi predstavljeno v tem delu, je bilo razvito v ta namen. Iz prvotnih osmih grafitnih materialov smo pri zahtevnejših obratovalnih pogojih izbrali tri grafitne materiale (trdi ogljik, elektrografit in polimerno vezan grafit) in jih nadalje podrobneje preučevali v isto-parnih kontaktih in v parih z bakrom. Pri vseh pogojih smo zaznali nastanek specifičnih površinskih filmov, ki ključno vplivajo na lastnosti drsnega električnega kontakta. Gladek, kompakten film, ki prekriva večino kontakta praviloma omogoča dobre tribološke lastnosti in stabilno obratovanje kontakta. Z grafit/grafit pari je možno doseči boljše tribološke in električne lastnosti kot z grafit/baker pari. Izbrani polimerno vezan grafit se je izkazal za najprimernejšega tako v paru z bakrom, še posebej pa v isto-parnem kontaktu. Smer električnega toka nima vpliva na obnašanje grafit/grafit kombinacij medtem, ko se pri grafit/baker kombinacijah negativne grafitne površine bolj obrabljajo od pozitivnih grafitnih ter pozitivne bakrene površine bolj od negativnih bakrenih površin. Rezultati dokazujejo velik potencial grafit/grafit materialnih kombinacij v disk-disk drsnem električnem kontaktu, saj je možno doseči dobro učinkovitost kontakta in zelo nizko obrabo.

• Jezik: Slovenski jezik
• Ključne besede: drsni električni kontakti, trenje, obraba, električna upornost, električni tok, površinski filmi, grafitni materiali
• Vrsta gradiva: Doktorsko delo/naloga
• Tipologija: 2.08 - Doktorska disertacija
• Organizacija: FS - Fakulteta za strojništvo
• Kraj izida: Ljubljana
• Založnik: [D. Poljanec]
• Leto izida: 2018
• Št. strani: XXVI, 149 str.
• PID: 20.500.12556/RUL-105872
• UDK: 539.92:621.8(043.3)
• COBISS.SI-ID: 16482587
• Datum objave v RUL: 21.12.2018

POLJANEC, Dejan, 2018, Tribološko optimiranje aksialnih drsnih obročev za avtomobilske alternatorje [na spletu]. Doktorska disertacija. Ljubljana : D. Poljanec. [Dostopano 25 april 2025]. Pridobljeno s: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=slv&id=105872

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Tribological optimization of axial slip rings for automotive alternators

Izvleček

In the PhD thesis we have studied the influence of operating parameters (sliding velocity, normal contact force, electrical current and direction of the current) on the tribological and electrical properties of the innovative design of sliding electrical contact. A dedicated tribological test rig was developed for this purpose, and is also presented in this thesis. Out of the initial eight graphite materials, three graphite materials (hard carbon, electrographite and polymer-bonded graphite) were selected under the demanding operating conditions and were further tested and studied in detail. They were running against self-mated contacts and against copper. In all conditions, a specific surface film formation was detected, which have a key effect on the properties of the sliding electrical contact. Smooth, well-compacted film, that overlaps most of the contact, usually gives good tribological properties and stable contact operation. With graphite/graphite combinations better tribological and electrical properties than with graphite/copper combinations can be achieved. The chosen polymer-bonded graphite has proved to be the most suitable, both in pair with copper, and especially in contact with itself. The direction of the electrical current has no influence on the behaviour of the graphite/graphite combinations. Meanwhile, in the case of the graphite/copper combinations, the negative graphite surfaces wear more than the positive graphite surfaces, and the positive copper surfaces wear more than the negative copper surfaces. The results demonstrate the great potential of graphite/graphite material combinations in the disc-disc sliding electrical contact, as it is possible to achieve a good efficiency of the contact and very low wear.

• Ključne besede: sliding electrical contacts, friction, wear, electrical resistance, electrical current, boundary film, graphite materials