Stručni rad
THE INFLUENCE OF BASE OILS AND VISCOSITY IMPROVER ON LOW TEMPERATURE PROPERTIES OF GEAR OILS
Danka Šikuljak
; Rafinerija ulja Modriča, BiH
Omer Kovač
; Rafinerija ulja Modriča, BiH
Novak Damjanović
; Optima Grupa, Banja Luka, BiH
Sažetak
The main function of gear oils in motor vehicles (transmission and differential) is to transfer power from the engine to the axle and wheels. During operation, gears tooth surfaces in these elements are exposed to extremely high pressures and impact loads. In order to ensure proper operation and adequate lubrication of all elements, oils used in these machine elements must provide following properties: good viscosity properties (in order to provide sufficient oil film thickness at elevated temperatures), protection against wearing and damaging at conditions of extreme pressures and loads, as well as excellent low-temperature properties for easier shifting in cold weather.
Besides the above mentioned properties, modern gear oils must also have nothing less important properties as: high thermal-oxidation stability, extended oil drain interval, low foaming tendency, corrosion protection, high shear stability, etc. Meeting the above requirements is achieved by using of high quality base oils (groups II, III, IV and V) and selected additive package. Unlike conventional base oils, these oils have significantly better low-temperature properties and therefore by applying of such oils improved efficiency is achieved.
This paper presents results obtained in researching the influence of base oils and two polymer types on properties of gear oils, by focusing on its low-temperature properties. In the gear oils formulations were used group III, group IV and group V base oils. For the evaluation of low-temperature properties were used results for dynamic viscosity measurments perfomed by Brookfield viscometer - test method ASTM D 2983 (under low shear rate) and Cold Cranking Simulator - test method ASTM D 5293 (under high shear rate).
Ključne riječi
gear oils; lubrication; low-temperature properties; base oils; additives
Hrčak ID:
159033
URI
Datum izdavanja:
6.4.2016.
Posjeta: 1.659 *