Patent Application
20070026911
The present invention relates to agricultural harvesting machines, such as combines, and, more particularly, to straw choppers for such combines.
Straw Choppers are used on agricultural harvesting machines to reduce the size of crop material, other than grain, that is processed by the harvesting machine. Typically, the straw chopper includes a housing that encloses a rotor. The housing is provided with an inlet for receiving crop material other than grain that has been processed and an outlet for distributing the chopped crop material back to the field. The housing is also provided with a bank of stationary cutter knives. The rotor is provided with a plurality of pendulously mounted straw chopper blades that cooperate with the stationary knives to chop the crop material entering the straw chopper. The rotor typically includes a cylindrical tube having a plurality of blade mounts distributed around the periphery of the rotor. The straw chopper blades are pendulously mounted to the blade mounts.
It is known to provide a fan at each longitudinally outboard end of the chopper blades. The fan helps to cast the non-grain crop material from the rear of the combine. The fan may include fan blades having a generally L-shaped configuration, with one leg lying in a plane extending generally parallel to the direction of rotation, and a transverse leg lying in a plane extending generally perpendicular to the direction of rotation. The transverse leg has a radially extending edge which simply allows the air to flow around the edge and off the blade as the blade rotates during use.
What is needed in the art is a fan for a straw chopper having enhanced air flow.
The present invention provides a straw chopper with a fan having scoop shaped fan blades.
The invention comprises, in one form thereof, a fan for a straw chopper in an agricultural harvesting unit. The fan includes a hub rotatable in a direction of rotation, and a plurality of fan blades connected with the hub at a plurality of angularly spaced locations about the hub. Each fan blade has a generally U-shaped portion with a rear wall and a pair of side walls extending from the rear wall in the direction of rotation.
The invention comprises, in another form thereof, a straw chopper for an agricultural harvesting unit. The straw chopper includes a housing, and a rotor carried by the housing. The rotor includes a center chopping section and a pair of fans respectively positioned at longitudinally outboard ends of the center chopping section. Each fan includes a hub rotatable in a direction of rotation, and a plurality of fan blades connected with the hub at a plurality of angularly spaced locations about the hub. Each fan blade has a generally U-shaped portion with a rear wall and a pair of side walls extending from the rear wall in the direction of rotation.
Crop processing unit 24 threshes and separates the harvested crop material. Crop processing unit 24 includes a rotor 26 located inside a rotor housing 28. Rotor 26 includes a cylindrical rotor drum having a number of threshing elements for threshing the harvested crop material. Grain and chaff fall through grates on the bottom of crop processing unit 24 to cleaning system 9 which removes the chaff and directs the clean grain to a clean grain elevator (not shown). The clean grain elevator transports the clean grain to grain tank 30. The clean grain in tank 30 can be unloaded into a gravity wagon or truck by an unloading auger 32.
Crop material other than grain is expelled from axial crop processing unit 24 to discharge beater 34. Discharge beater 34 in turn propels the harvested crop material other than grain to straw chopper 36, which chops and flails the non-grain material back to the field. The operation of combine 10 is controlled from an operator's cab 38.
Although the invention is illustrated as being used on a rotary combine, the present invention can be used on other combine types including conventional straw walker combines and hybrid combines having transverse threshing cylinders and rotary separators.
Referring now to
Rotor 42, shown in more detail in
Referring to
Each fan blade 64 has a mounting or proximal end 70 and a radially outboard or distal end 72. Each fan blade 64 has a generally U-shaped portion as viewed and extending from distal end 72. The U-shaped portion is defined by a rear wall 74 and a pair of side walls 76 extending from rear wall 74 in direction of rotation 68. Each fan blade 64 also has a generally L-shape as viewed perpendicular to one of side walls 76. In other words, each fan blade 64 has a “scoop shape” open in the direction of rotation which assists in directing an enhanced flow of air from straw chopper 36 for better distributing the non-grain material to the field.
Each fan blade 46 is also shown as including a pair of ears 78 extending from respective side walls 76 near proximal end 70. Each ear 78 extends generally in the direction of rotation 68, although also at an acute angle. Ears 78 are mounted on opposite sides of ring 62, and allow free movement of fan blades 64 at the mounting locations with ring 62, such as at rest or during a plugging situation. Of course, centrifugal force during operation causes fan blades 64 to move to the radially outward position as shown in
Referring to
To also assist in providing enhanced air flow, housing 40 of straw chopper 36 may include a plurality of optional air intake holes 86 at opposite longitudinal ends of rotor 42 (
Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.
The entire right, title and interest in and to this application and all subject matter disclosed and/or claimed therein, including any and all divisions, continuations, reissues, etc., thereof are, effective as of the date of execution of this application, assigned, transferred, sold and set over by the applicant(s) named herein to Deere & Company, a Delaware corporation having offices at Moline, Ill. 61265, U.S.A., together with all rights to file, and to claim priorities in connection with, corresponding patent applications in any and all foreign countries in the name of Deere & Company or otherwise.
