Threshing rotor inlet flight extension
View Patent ↗The extension has an elongate blade shape and is positionable in radially outwardly extending relation along a leading edge of a rotor inlet flight, the blade having a leading edge located forwardly of the leading edge of the flight so as to rotate in advance thereof. The leading edge preferably has a curved, swept back shape relative to the rotational direction, which gradually increases in slope in the radial outward direction, so as to facilitate smooth acceleration of the crop material in the radial outward direction. The extension has a rearwardly facing blade or crop flow surface oriented at an angle of attack less than the angle of attack of the associated flight, so as to be less blunt and to facilitate smooth crop material flow onto the flight. The extension shape generates a rearwardly directed air flow when rotated.
1. An extension for a helical flight extending around a front inlet end of a rotor of a threshing system of an agricultural combine, the rotor being rotatable in a predetermined rotational direction about a rotational axis therethrough and the flight including a leading edge extending radially outwardly from the front inlet end of the rotor and a rearwardly facing helical crop flow surface extending rearwardly from the leading edge at a first predetermined angle of attack relative to a plane perpendicular to the rotational axis, for conveying crop materials from adjacent the inlet end of the rotor radially outwardly and rearwardly when the rotor is rotated, the extension comprising:
an elongate blade shape member removably mountable in radially outwardly extending relation along the radially outwardly extending leading edge of the flight, the blade shape member being disposed so as to be located forwardly of the leading edge of the flight with respect to the predetermined rotational direction along at least a substantial portion of a radial extent thereof when mounted thereon, the blade shape member having a leading edge having a curved swept back shape, and a rearwardly facing crop flow surface extending rearwardly with respect to the predetermined rotational direction from the leading edge of the blade shape member to the helical crop flow surface of the flight along substantially the entire radial extent of the blade member and is oriented at a second predetermined angle of attack less than the first predetermined angle of attack, such that when the rotor is rotated in the predetermined direction the member will accelerate crop material that comes into contact with the leading edge thereof radially outwardly and rearwardly onto the flight and generate a rearwardly directed air flow.
2. The extension of claim 1 , wherein the leading edge of the blade shape member extends radially outwardly and rearwardly from adjacent the forward inlet end of the rotor to a radial outermost edge of the flight.
3. The extension of claim 2 , further comprising a hub mountable to the rotor forwardly of the forward inlet end thereof and including a radially outwardly extending extension having a leading edge at least generally tangent to a curved radial outer periphery of the hub and extending radially outwardly to adjacent to a radial inner edge of the blade shape member.
4. The extension of claim 3 , wherein the blade is separate from the hub and is mountable to the hub and the helical flight using fasteners.
5. The extension of claim 1 , wherein the first angle of attack is about 135 degrees and the rearwardly facing crop flow surface of the blade shape member is oriented at about a 147 degree angle to the rearwardly facing helical crop flow surface of the flight.
6. A threshing rotor for a threshing system of an agricultural combine, comprising:
a front inlet section rotatable in a predetermined rotational direction about a rotational axis therethrough and a plurality of helical flights extending rearwardly and oppositely from the rotation direction around the inlet section, each of the flights including a front leading edge extending radially outwardly from a front end of the front inlet section and a rearwardly facing helical crop flow surface extending rearwardly from the leading edge at a first predetermined angle of attack of about 135 degrees relative to a plane perpendicular to the rotational axis; and
elongate blade shape extensions mounted in radially outwardly extending relation along and forwardly of the leading edge of each of the flights in the predetermined rotational direction, respectively, each of the extensions having a leading edge having a curved shape which is swept back both rearwardly and relative to the predetermined rotational direction and extends to adjacent to a radial outermost edge of the flight and a rearwardly facing crop flow surface extending from the leading edge of the extension to the helical crop flow surface of the flight and oriented at a second predetermined angle of attack oriented at about a 147 degree angle relative thereto, such that when the rotor is rotated in the predetermined direction the extension will accelerate crop materials that comes into contact with the leading edge thereof radially outwardly and rearwardly to the flight and generate a rearwardly directed air flow.
7. The rotor of claim 6 , wherein the extensions are removable from the flights.
8. The rotor of claim 6 , further comprising a hub mountable to the front inlet end and including a curved radial outer surface and radially outwardly extending extensions having leading edges at least generally tangent to the curved radial outer surface and extending radially outwardly to adjacent to radial inner edges of the blade shape extensions, respectively.