EFFECT OF BLADE ANGLE TYPES AND FORWARD SPEED ON THE PERFORMANCE OF THE MURRAY-15.5HP LAWN MOWER

Abstract

A field experiment was conducted to design, implement, and test the effect of blade angle represented by cutting angle and foreword speed on the performance of a MURRAY-15.5hp lawn mower machine. Three types of blades with cutting angles of 20^o, 25^o, and a straight angle were used, as well as three forward speeds of 2.99, 4.32, and 5.60 km h-1. The slippage percentage, field productivity, material quantity and total costs were studied. The results indicated the following: decreasing the cutting angle from 25^o to 20^o and then to a straight angle considerably decreases the slippage percentage and a significant decrease in total costs .Also, a significant increase in the field and Material productivity. Increasing the foreword speed resulted in a significant increase in the slippage percentage and a significant increase in in the field and material productivity, and decrease in the total costs. The interaction between the straight blade type and the forward speed 2.99 km h^-1 led to the lowest slippage at 8.34%, while the interaction between the straight blade type and forward speed 5.60 km h^-1 resulted in the lowest total costs amounted to 12036 dinars*hectare^-1 and the highest field productivity 0.360 ha h^-1 while the highest material productivity was 121.25 kg h^-1.