Changes in the Key Physicochemical Parameters and Selected Trace Elements of Oil Due to Its Use in Hydraulic System of Woodworking Equipment

The research presented supported a comprehensive assessment of the condition of real oil samples of the HM quality class and VG 46 viscosity grade as functions of oil usage time in the hydraulic system of two round timber sorting and transport carriages (RSTW_I and RSTW_II) Baljer & Zembrod intended for handling wood logs by following the degradation and concentration of abrasive metals in the oil. The oil data were collected every Δ = 500 operating hours during one year by off-line monitoring of hydraulic oil. Measured values were compared to the acceptability limits. Multivariate associations were analysed using a principal component analysis (PCA; Statistica 12.0) to describe the patterns of co-variation among the examined traits. Based on the data obtained, it was observed that the oil in RSTW_I was more oxidatively stressed in contrast to the oil in RSTW_II despite it being subjected to an excessive wear mode.