Development of Side-discharge Type Mid-mower Attached to a Tractor

Abstract

A side-discharge mid-mower attached to a 22 kW-powered tractor (Tongyangmoolsan Co. Ltd., T-300) was developed. Relationships between rotating velocity of a blade and the wind velocity at the outlet of the mid-mower, the required power to operate the mid-mower, cutting and discharging conditions relative to height of lawn, and working speed were tested. Results showed that the proper height and width of the outlet were at 195 mm and 520 mm, respectively. Reliable cutting height of lawn was about 100 mm with blades having bended angles greater than 20°. The torque limit at mid-PTO of the tractor was about 270 Nm and the required maximum torque for mowing was about 223 Nm. Therefore, the mid-PTO of the tractor has 17% more torque available than the maximum torque of the mid-PTO for mowing. The total PTO power requirement to propel the mid-mower was 8 - 10 kW at a working speed of 7 km/hr and 1.8m width of the mower. The field capacity of the prototype mid-mower attached to the tractor (22Kw) was about 1.26 ha/hr. Consequently, the prototype mid-mower was fully compatible with a small tractor.