| 摘要 |
<p>A combine harvester having threshing and separating mechanism, sieve through which crop material separated by the threshing and separating mechanism passes, cleaning mechanism having a fan operable to blow air through the sieve and hence clean the crop material on the sieve, the fan being driven by variable speed drive, sensor operable to sense the fore-and-aft inclination of the machine and produce a signal representative thereof, a device for selecting a nominal rotational speed for the fan during operation of the machine on level ground and producing a signal representative of that nominal speed, a device for combining the inclination signal and the nominal speed signal to produce a signal representative of the desired speed of the fan as a function of the fore-and-aft inclination of the machine, mechanism for measuring the actual rotational speed of the fan, and control mechanism responsive to the desired fan speed signal and the actual fan speed signal to produce a command signal for application to the variable speed drive, whereby the rotational speed of the fan is adjusted as a function of the fore-and-aft inclination of the machine.</p> |
