Development of High-Speed Rotary Harrow for Puddling (Part 2)

Studies on Blade Specifications and Outline of the Developed Rotary Harrow

Abstract

We conducted fundamental tests on the blade of puddling harrows and found the following results. (1) The blade arrangement in which a pair of blades was installed 15mm apart laterally yielded higher performance on soil-pulverizing and residue-burying than the conventional blade arrangement. (2) The PTO specific power of the harrow with rotary blades having a cutting angle of 95° was 5 to 10% lower than that of the harrow with 105° cutting angle blades. However the residue-burying performance of the 95° cutting angle blade was worse than that of the 105° cutting angle blade. (3) Increasing the blade rotating speed 8% degraded the residue-burying performance and increased the PTO specific power by 14%. Based on the results of fundamental tests, we manufactured prototype harrows. These harrows had the following features. (1) A new large rake was installed in front of the rear cover. (2) The arrangement of the blades was changed. (3) The inner volume of the rear cover was larger than that of conventional harrows.