Utjecaj triboloških procesa mehanizma slobodnog hoda na radne karakteristike impulsnih tarnih varijatora

The impulsive friction variators are very specific transmitters. They are characterised by the periodical impulse transmission of power and motion. For research purposes, the device was made to simulate wear of the tribomechanical system: external envelope (coulisse) – roller and roller-shaft in the free motion mechanism with use of the impulsive friction variators. Monitoring of the elements of tribomechanical system was conducted by recording the changes of dimensions depending on the investigation time. Roughness parameters were measured and wear traces of the tribomechanical system were recorded. It was concluded that at the shaft (star), a dominant mechanism of wear is pitting, and that destruction of the oil film precedes the damage at the coulisse (roller). By analysing the change of the gap and influence of the change of wedging angle, it is determined that the period of intensive wear at the beginning and the period of constant wear can be differentiated. It was concluded that the change of the gap clearly represents theImpulsni tarni varijatori su vrlo specifični prijenosnici. Karakterizira ih impulsni periodični prijenos snage i gibanja. U cilju istraživanja izrađen je ispitni uređaj za simuliranje trošenja tribosustava: vanjski prsten (kulisa) - valjčić i vratilo - valjčić u mehanizmu slobodnog hoda pri radu impulsnih tarnih varijatora. Praćenje elemenata tribosustava vršeno je snimanjem promjena dimenzija u ovisnosti o trajanju ispitivanja. Mjereni su parametri hrapavosti i snimani tragovi trošenja elemenata tribosustava. Zaključeno je da je kod vratila (zvijezde) dominantni mehanizam trošenja pitting, a da oštećenju vanjskog prstena (valjčića) prethodi razaranje uljnog filma. Analizom promjene zazora i utjecaja promjene kuta zaklinjavanja utvrđeno je da se mogu razlučiti period početnog intenzivnog trošenja i period ustaljenog trošenja. Zaključeno je da promjena zazora jasno prikazuje krivulje trošenja triboelemenata. Povećanje zazora direktno utječe na promjenu kuta zaklinjavanja, a samim time i na povećanje neravnomjernosti rotacije izlaznog vratila