The present invention relates to a transmission for combined shredding and mixing trucks for fibrous zootechnical products.
Mixing trucks are known in the zootechnical field that are constituted by a wheeled chassis which is towed or self-propelled with an independent power plant and supports a substantially inverted frustum-shaped container, which is open at the top and contains a scroll or helix with a vertical axis for shredding and mixing fibrous products for feeding livestock.
The scroll, which has a substantially conical profile, lies along a shaft which is rotatably coupled to the chassis in a downward region and, in an upward region, to a cross-member which is fixed between two opposite parts of the edge of the container.
A mechanical transmission with a reduction unit, i.e., a bevel gear pair and gear-based couplings, is currently used to transmit the motion from the driving motor to the scroll shaft.
Although this type of transmission has been used extensively so far, it has been found to have some drawbacks which are mainly due to the considerable stresses to which it is subjected.
The presence of the gears produces overheating and considerable load losses that require high motor power levels.
Another drawback is due to the fact that the upper supporting cross-member of the shaft that supports the scroll creates an obstacle, when feeding large bales into the container, and consequently creates considerable problems in operation.