| 摘要 |
The present invention is related to a combine harvester comprising a pair of track units or equivalent ground engaging means at the front of the harvester. The track units are suspended in the way known in the art, i.e. the frame of the units is pivotable about a centrally placed pivot axis, the axis dividing the track unit between a front and rear portion, so that the pivoting of the track unit results in upward and downward tilting of the front and rear portions. For each of the track units, the harvester comprises at least one variable length actuator mounted between the chassis of the harvester and the frame of the track unit, the actuator being mounted so that it is capable of actuating an upward and/or downward tilting of the front portion of the track unit. The actuator is operated to counteract an excessive downward and/or upward tilting of the front portion of the unit. The actuator may be operated by a control mechanism working on the basis of measurements performed by suitable sensor arrangements that monitor or predict the downward or upward tilting. The actuators may be part of a lifting system for the entire frame of the actuator. In the latter case, the cleaning arrangement of the harvester may be placed above the track units, the cleaning arrangement having a functional width that is larger than the distance between the track units. |
