Factor Analysis on the Relationship of Bearing Pressure and Sinkage Behaviours Using Model Track of Combine
1982 Volume 43 Issue 4 Pages 533-540
Details
1982 Volume 43 Issue 4 Pages 533-540
To clarify the relation between the sinkage of combine harvester and soil moisture content, shape and pressure of ground contact surface, test was conducted using 1/5 scale models of track of combine harvester.
The outline of experimental results are as follows.
1) Nine models shown in Fig. 2 were used. Factors which influenced upon the sinkage are the width and contact area of track and soil moisture content when the ground contact pressure is under 0.2kgf/cm2 (19.6kPa). The influence of tread length is not significant in this test.
2) When the ground contact pressure is lower than 0.2kgf/cm2 (19.6kPa), the sinkage of smaller track is less than that of larger one under the same ground contact pressure. This means that the sinkage of the track depend on the weight of combine. When the tracks have the same contact area, the sinkage of the track having narrower width is less than that of wider one. This means that shorter track is easier to sink than longer one.
3) Soil moisture content is the main factor which affects to the sinkage of track. Even if the ground contact pressure is lower than 0.2kgf/cm2 (19.6kPa), the sinkage of track increases rapidly as the soil moisture content increases. The sinkage is remarkable when the soil moisture is near the liquid limit. The sinkage is more when the soil is kneaded in the same moisture content. These results indicate that the soil moisture content and the soil structure are the important factors for the sinkage of track. Under high soil moisture content, the influence of the shape of track is not recognized.
4) The effect of the tread length of tracks is not clear.
5) Assuming that sinkage behaviours of combine harvester exhibit a similar tendency to the model experiments we have done, it can be said that the elements for designing combine harvester are: the weight of combine should be as light as possible, the length of track should be long enough within the limit of giving no serious effect on turning operation and the tread of tracks should be arranged so that they do not run on the same trace. However, it must be born in mind that the sinkage behaviour is more heavily affected by the soil moisture content than the shape of track.
