Generally, forage harvesters chop crop material, such as grass or maize, into small particles for storage and subsequent feeding to livestock. Conventional harvesters comprise a rotating cutterhead with a plurality of knives, which cooperates with a stationary shear bar to cut the crop material fed thereto into small particles and deliver it to discharge means.
The comminuted crop material is normally conveyed to the inlet of a blower housing, in which paddles of a blower rotor impart sufficient energy thereto for upward ejection through a blower outlet into a curved discharge spout, which directs the flow of crop material sidewardly or rearwardly into a collecting vehicle.
Conventionally, the blower housing is connected to the harvester frame and rotatably supports the discharge spout. Efficient operation of the blower requires minimal play between the rotor and the housing. Otherwise, a portion of the crop material will not be thrown out of the blower, but accumulate on the inside of the housing and consume a portion of the rotative energy.
In most cases however, the blower arrangement comprises a substantially rigid rotor, mounted in a rather flimsy housing, which is made out of plate material A blower of this type is shown in U.S. Pat. No. 4,220,289. The housing is subject to deformation during its assembly to the harvester frame and the subsequent mounting thereto of the discharge spout. In order to prevent interference between the rotor and its paddles on the one hand, and the housing on the other hand, a considerable nominal play has to be applied inbetween. After the assembly of the blower to the harvester frame and the mounting of the spout, the efficiency of the blower can be enhanced by a time-consuming readjustment of the rotor and the paddles.
Vibrations which are induced during harvesting operations upon the housing by the voluminous spout, and deformations caused by the weight and the rotation of said spout may also engender an interference of the housing with the rotating parts. These phenomena require an even larger nominal play between these elements and may necessitate a further readjustment of the rotor and the paddles after a short utilization of the harvester.