Abstract
The characteristics of soil reaction forces onto a lug of cage wheel with double rims are presented in this paper, analyzing measured data in actual sandy and paddy fields. Radial and tangential forces for the rim, which acted to one lug, and moments by the forces were measured by extended octagonal ring transducers, which were fixed on left and right cage wheels. The resulting pull and lift forces, which were developed by one lug, depended on a number of factors including: soil type, wheel sinkage, lug angle and so on. Larger lug angle resulted in sharp distributions of pull and lift forces owing to the shorter contact length due to the smaller sinkage. The maximum values of pull and lift forces of one lug had a linear relationship with the slippage. The resistance loss of the cage wheel, which was calculated by integrating and accumulating horizontal components of lug forces and by comparing with measured pull, was the minimum at 45 degrees lug angle in paddy field and at 60 degree lug angle in sandy field. These lug angles were the same as the optimum lug angle from the viewpoint of tractive efficiency as reported in Part 1 of this study.
