Tomas Nordfjell
Dept. of Forest Resource Management, Section of Planning and Operational Efficiency, Swedish University of Agricultural Sciences, S-901 83 UMEÅ, Sweden
Louise Johansson
SMP Svensk Maskinprovning AB (The Swedish Machinery Testing Institute), S-904 03 UMEÅ, Sweden;
Jörgen Hellström
Dept. of Forest Resource Management, Section of Planning and Operational Efficiency, Swedish University of Agricultural Sciences, S-901 83 UMEÅ, Sweden;
Rolf Gref
Faculty of Forestry and Wood Technology, Mendel University of Agriculture and Forestry, Lesnicka 37. 613 00 BRNO, Czech Republic
Alois Skoupy
Dept. of Forest Resource Management, Section of Planning and Operational Efficiency, Swedish University of Agricultural Sciences, S-901 83 UMEÅ, Sweden
Dimitris Athanassiadis
Dept. of Forest Resource Management, Section of Planning and Operational Efficiency, Swedish University of Agricultural Sciences, S-901 83 UMEÅ, Sweden.
Abstract
A saw-bar with a saw-chain is a common tool in both mechanized and motor-manual harvesting operations. The friction between the saw-bar and the saw-chain must be reduced by lubrication. A precise oil flow control can reduce the amount of oil needed. Traditionally, mineral oils have been used, but the use of biodegradable vegetable-based oils has increased. The goal of this study was to evaluate the lubrication characteristics at different oil flows of two vegetable-based and one mineral-based saw-chain oil. The study was done on an experimental rig with a saw-chain speed of 23 m/s and with pressure between the saw-chain and a rotating rubber roller. The temperature of the saw-bar was used as an indicator of the lubrication efficiency. The saw-chain tension was constant and independent of temperature. In general, increased oil flow resulted in a lower temperature. For rapeseed oil and pine oils, the results were consistently significant between oil flows of 2 and 6 ml/min. At an oil flow of 2 ml/min and 5 minute test time, pine oil resulted in the highest temperature (121°C, standard deviation [SD] 6.4) and at 6 ml/min the lowest temperature (99°C, SD 1.1) compared with the other oils. No difference in temperature was found between mineral oil and rapeseed oils at oil flows of 2 or 6 ml/min. An oil flow of 2 ml/min was found to be enough to prevent high temperatures for all oil types. The study method, with an adjustable experimental rig as the tool, was found to be suitable for studies on lubrication of the saw-bar and saw-chain.
