In electrical motors electrical energy is transformed into mechanical energy or the other way around. Electrical energy has to be transferred from a stationary component into a moving one, which is done by a copper commutator in sliding contact with carbon brushes. Wear is occuring at surfaces of both components during dry sliding. For reduction of friction and wear rate solid lubricants are added to the carbon brush compositions. It was observed that during sliding a solid lubricant film is formed on the surface of the copper commutator. This transfer film has a limited life. After failure of the layer a new film is formed from the reservoir of the carbon brushes. Various solid lubricants in carbon brushes were tested. It was found, that certain solids form very thin layers with good adhesion on commutator surfaces, which improves tribological performance of both moving components. In particular wear rate, friction and noise is reduced significantly. This resulted in much longer service life of electrical motors for automotive applications.
Advancements of tribological performance of carbon brushes in electrical motors
Fortschritte auf dem Gebiet der tribologischen Wirksamkeit der Kohlebürsten in Elektromotoren
Tribology 2000 - Plus, International Colloquium, 12 ; 3 ; 1599-1603
2000
5 Seiten, 7 Bilder, 1 Tabelle, 3 Quellen
Aufsatz (Konferenz)
Englisch
Elektromotor , Kohlebürste , Tribologie , Kommutator , Kupfer , Gleitkontakt , Verschleißrate , Reibung , Festschmierstoff , Schmierfilm , Adhäsion , Test (Prüfung) , Geräuschminderung , Lebensdauer , Automobil
Technological advancements in medium and high voltage motors
Online Contents | 2003
Engineering Index Backfile | 1912
|Maintaining carbon brushes for good commutation
Engineering Index Backfile | 1929
|Analysis of the Generation Mechanism of Chirp Noises in the Brushes of Blower Motors
SAE Technical Papers | 1996
|British Library Conference Proceedings | 1995
|