The Effect of Viscosity Index on the Efficiency of Transmission Lubricants

Establishing the regularities of correlation between ambient temperature and fuel consumption by city diesel buses

“…A lower viscosity means lower circular mass flow velocity losses in the flow channel of the hydrodynamic transmission [21]. According to the study results presented in [22], transmission efficiency has a linear dependence on the temperature of the transmission oil in idle and full load operating modes. In partial load modes, the transmission efficiency ranges from 1 % in the temperature range from −5 °C to +20 °C.…”

“…4, 5) and the bus technical characteristics were taken as initial data (Table 1). The relationships between air density, rolling resistance, transmission efficiency, and ambient temperature were taken from [22,23,25], respectively.…”

Investigation of the Influences of Thrust Loads Resulted by Helix Angle Directions of Planetary Gear Sets on Bearing Power Losses in Automotive Planetary Gear Trains

“…Studies on power loss subjects related to gear pairs, bearings, and gear systems have been extensively performed and presented by many researchers [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. For rolling element bearings, empirical models of power losses and friction moments involving mechanical loads and fluid viscous frictions are found in the literature [1][2][3], while the SKF Group [4] developed a model composed of individual contributions of rolling, sliding, sealing and drag.…”

“…A bearing model presented by Tomovic [7] is a load calculation model using a load factor to predict the most loaded rolling element of a bearing, including internal radial clearance. As a critical factor affecting power losses, viscometric study of automatic transmission fluids (ATF) on power efficiency was performed under various oil temperatures by Vickerman et al [8], and it was presented that viscous properties of ATF affect mechanical power efficiency in transmission operations.…”