An impeller blower assembly for a crop residue chopping and spreading device of a combine harvester and associated impeller blades

Abstract

An impeller blower assembly for a crop residue chopping and spreading device of a combine harvester (10) having a rotor rotatable about an axis of rotation (88) and a plurality of impeller blades (84) distributed around the periphery of the rotor, characterized in that the impeller blades (84) are made of nodular cast iron.

Description

Technical Field

[0001] The present invention relates to an impeller blower assembly and associated impeller blades for a crop residue chopping and spreading device for a combine harvester, the impeller blower assembly having a rotor rotatable about a rotation axis, and a plurality of impeller blades distributed around the outer periphery of the rotor. Background Technology

[0002] A combine harvester is a large machine that harvests, threshes, separates, and cleans agricultural crops containing grain. The harvested net grain is stored in a grain bin located on the combine harvester. The threshed straw is typically either chopped and spread across the field along the width of the cutting unit, or guided around the straw shredder and distributed as unchopped material in a swathe on a section of the field for later collection by a baler. Crop residues remaining at the rear exit of the cleaning unit, such as chaff and small pieces of straw, are spread across the field by a chaff spreader or guided and spread across the field by the straw shredder.

[0003] As combine harvester output has increased in recent decades, a wider cutting unit and consequently a wider spread are required, which cannot be achieved by the straw chopper alone. Therefore, a so-called impeller blower is used downstream of the straw chopper to accelerate the movement of crop residue and expel it. Impeller blowers are typically arranged in pairs side by side and include rotors housed within a casing, which are configured to be driven to rotate by a drive.

[0004] In the prior art, rotors are equipped with blades to accelerate the movement of crop residues. This may involve blades that are inherently flat or inherently twisted, or blades that are otherwise curved, for example, as shown in DE 199 08 111 C1, DE101 33 965 A1, DE 10 2010 002 467 A1, EP 3 537 866 A1 and US 2007 / 0015 556 A1, or the blades may be equipped with sharp, tapering or cylindrical finger-like elements at their outer ends (EP 2347 645 A1, EP 3228 174 A1 and EP 4 115 723 A1).

[0005] In the prior art, flat blades are made of injection-molded plastic or metal; in particular, actuators made of cast steel are used (EP 4 115 723 A1). In the prior art, cylindrical blades formed into finger-like rakes are made of spring steel or forged steel. Summary of the Invention

[0006] Practice has shown that blades made of spring steel have insufficient service life, while forged steel requires higher manufacturing costs.

[0007] The purpose of this invention is to avoid or at least reduce the aforementioned disadvantages.

[0008] Achievement of the goal

[0009] According to the invention, this objective is achieved through the teachings of claims 1 and 8, wherein features that advantageously improve the achievement of this objective are set forth in the other claims.

[0010] The impeller blades are made of ductile iron. This material is characterized by low manufacturing cost, light weight, low wear, and high stability, making it particularly suitable for use as impeller blades. Ductile iron is easy to cast and can be better machined (ground), and is less expensive than steel. Furthermore, compared to cast steel, ductile iron has higher wear resistance and a higher tensile yield point, while cast steel requires more complex and expensive machining tools. The unit cost of impeller blades made of ductile iron is lower than that of similar impeller blades made of cast steel.

[0011] The impeller blade may be presented as a one-piece finger-shaped rake, including a proximal fastening portion detachably connected to a rotor cage or detachably connected to a rotor cage, and a plurality of fingers extending from the fastening portion to the distal end of the impeller blade. These fingers are preferably located in a common plane and form a finger-shaped rake. These fingers may be located in the same common plane as the fastening portion, and these fingers have a rectangular cross-section, the extent of which in the common plane is greater than the extent in a direction perpendicular to the common plane. These fingers may begin at the distal end and continuously taper from the fastening portion in the direction perpendicular to the common plane, and the width of the fingers remains constant over the length of the fingers when measured in the common plane. Attached Figure Description

[0012] Exemplary embodiments of the present invention will be explained based on the accompanying drawings, in which:

[0013] Figure 1 A partial cross-sectional side view of a combine harvester with a straw shredder and an impeller blower is shown.

[0014] Figure 2 A perspective view of the impeller blower as seen from the rear and lower rear; and

[0015] Figure 3 A perspective view of the blower blades is shown. Detailed Implementation

[0016] Figure 1An agricultural combine harvester 10 is shown, which has a chassis 12 with wheels 14 that engage with the ground. The wheels 14 are fixed to the chassis 12 and are used to drive the combine harvester 10 forward in a forward direction. Figure 1 In the middle, the combine harvester travels to the left. The operation of the combine harvester 10 is controlled by the cab 16. The cutting mechanism 18 is used to harvest the crop containing grain and feed it into the feed chamber 20. The harvested material is fed through the feed chamber 20 to the guide roller 22. The guide roller 22 guides the crop through the inlet transition section 24 and to the axial crop handling device 26. In the following text, directional expressions such as "forward" and "rearward" refer to the forward direction of the combine harvester 10. Figure 1 In the middle, the combine harvester is moving to the left.

[0017] The crop processing device 26 includes a rotor housing 34 and a rotor 36 disposed within the rotor housing. The rotor 36 includes a hollow drum 38 on which material handling elements for the loading section 40, threshing section 42, and separating section 44 are fixed. The loading section 40 is located at the front of the axial crop processing unit 26. Along the longitudinal direction, the threshing section 42 and separating section 44 are located downstream and rear of the loading section 40, respectively. The drum 38 has a truncated conical shape in the loading section 40. The threshing section 42 includes a truncated conical front portion and a cylindrical rear portion. A cylindrical separating section 44 of the drum 38 is located at the end of the axial crop processing unit 26. In addition to the axial crop processing unit 26, a tangential threshing drum and a subsequent axial separator or straw separator may also be used.

[0018] Grain and chaff falling through the threshing concave plates assigned to the threshing section 42 and the separating grids assigned to the separating section 44 are fed to the cleaning system 28, which includes a blower 46 and slat screens 48 and 50 that can be set to vibrate. The cleaning system 28 removes the chaff and conveys the clean grain to a slat screen elevator (not shown) via a screw conveyor 52. The slat screen elevator deposits the clean grain into a grain bin 30. The clean grain in the grain bin 30 can be unloaded onto grain trucks, trailers, or trucks via a discharge screw conveyor 32. The crop remaining at the rear end of the lower slat screen 50 is fed back to the crop processing unit 26 via a screw conveyor 54 and a tail conveyor (not shown). Crop residue (which mainly consists of chaff and small straw particles) discharged from the rear end of the upper slat screen 48 is conveyed by a vibrating disc conveyor 56 to the lower inlet 58 of the rear straw chopper 60.

[0019] The threshed straw from the separation section 44 is discharged from the crop treatment device 26 through outlet 62 and fed to the discharge drum 64. The discharge drum 64 interacts with the ground surface 66 below it, discharging the straw backward. The wall 68 that guides the straw into the upper outlet 70 of the straw shredder 60 is located behind the discharge drum 64.

[0020] The straw shredder 60 consists of a housing 72 and a rotor 74 installed within the housing. The rotor 74 is rotatable about an axis 74 extending horizontally and transversely to the forward direction. Shredder blades 76, distributed around the outer periphery of the rotor 74, are suspended in pairs to oscillate around and interact with corresponding blades 78 fixed to the housing. Two laterally arranged impeller blowers 82 are positioned downstream of the outlet 80 of the straw shredder 60. Figure 1 Only one of them is visible.

[0021] The impeller blower 82 includes a plurality of impeller blades 84, each impeller blade being rigidly connected to an upper circular disk 86, which is rotatable about a central axis of rotation 88. The disk 86 with the radially extending impeller blades 84 can be configured to be driven to rotate by a hydraulic motor 90 in all cases, which is attached above a base plate 102 connected to the housing 72 of the straw shredder 60. The impeller blades 84 are connected at their radially inner ends to radially extending fastening plates 96 by screws. The fastening plates 96 serve as retainers for the impeller blades 84 and are themselves connected to a central body 92, which may transition into a pointed cone 94 on its side facing away from the disk 86. The impeller blades 84 are presented as integral finger-shaped rakes, and the height of the central body 92 (without...) Figure 2 The cone 94 (not shown and can be omitted) is equal to the height of the impeller blade 84.

[0022] The straw shredder 60 defines an outlet plane that extends rearward and upward at an angle, from which crop residue is discharged. However, the impeller blades 84 of the impeller blower 82 rotate in an impeller blower plane that is inclined rearward and downward. Therefore, the impeller blower plane of the impeller blower 82 is inclined rearward and downward relative to the outlet plane of the straw shredder 60. Crop residue is conveyed by the impeller blower 82 within its impeller blower plane and discharged rearward and laterally, and scattered across the field in the width direction of the cutting mechanism 18. For further details regarding the possible housing of the impeller blower 82, see DE 102008 040 129 B4, the disclosure of which is incorporated herein by reference.

[0023] Now for reference Figure 3The impeller blade 84 is shown in perspective view. At its position fixed to the impeller blower 86, the impeller blade 84 includes a proximal, radially inward fastening region 98 defining an inner proximal end 108 of the impeller blade 84. The fastening region 98 includes a plurality of smaller holes 100 for receiving screws by which the impeller blade 84 is secured to the fastening plate 96. Larger openings 102 with a trapezoidal cross-section located between the holes 100 serve to reduce weight.

[0024] The impeller blade 84 also includes a plurality of fingers 104, five in the illustrated embodiment, but more or fewer fingers 104 may also be present. The fingers 104 extend parallel to each other, from the fastening region 98 to the outer distal end 106, with gaps between adjacent fingers. Thus, the fingers 104 form a finger-like rake. The fingers 104 and the fastening region 98 lie in a common plane. Considering the transverse direction relative to the longitudinal extent of the fingers 104, the dimensions of the fingers 104 within the plane occupied by the fastening region 98 and the fingers 104 are approximately constant, while the fingers taper gradually from the near inner end to the outer distal end 106 in a direction oriented transversely to the plane, i.e., gradually thinning outwards transversely to the plane. This results in a carrier of uniform strength, characterized by elasticity and long-term durability. The dimension of the finger 104 in the transverse direction within the plane is greater than its dimension in the direction perpendicular to the plane. The cross-section of the finger 104 is approximately a rectangle with rounded corners.

[0025] The impeller blade 8 is integrally cast from ductile iron using a casting process. To do this, a model of the impeller blade is first manufactured, which, after cooling, is slightly larger than the impeller blade 84. Using this model, a two-piece mold is created, filled with molten metal. After cooling, the mold is separated, the impeller blade 84 is removed, and it undergoes finishing (grinding and primer application).

[0026] A suitable material for ductile iron is JDM B8 grade N550B06, i.e., cast ductile iron, which has a matrix microstructure composed of perlite and ferrite (typical matrix phase distribution, with perlite content exceeding 50%), tensile strength exceeding 550 MPa, tensile yield strength exceeding 350 MPa, tensile yield strength exceeding 6%, and hardness ranging from 173 HBW to 255 HBW. The carbon content is particularly between 3% and 3.9%. Ductile iron can be used to manufacture impeller blades in a lightweight, low-cost, wear-resistant, and strong material, making it especially suitable for impeller blades currently used in combine harvester blower assemblies. This material particularly conforms to the EN-GJS-500-7 (GGG50) standard.

Claims

1. An impeller blower assembly for a crop residue chopping and distributing device for a combine harvester (10), the impeller blower assembly having a rotor rotatable about a rotation axis (88), and a plurality of impeller blades (84) distributed around the outer periphery of the rotor, characterized in that, The impeller blades (84) are made of ductile iron.

2. The impeller blower assembly according to claim 1, wherein, The impeller blade (84) can be presented as an integral finger rake, the finger rake including a fastener (98) at the proximal end, the fastener being detachably connected to the rotor's cage, and a plurality of fingers (104) extending from the fastener to the distal end (106) of the impeller blade.

3. The impeller blower assembly according to claim 2, wherein, The finger-shaped member (104) is located in a common plane and forms a finger-shaped rake.

4. The impeller blower assembly according to claim 3, wherein, The finger (104) and the fastening part (98) are located in a common plane.

5. The impeller blower assembly according to claim 3 or 4, wherein, The finger (104) has a rectangular cross-section, the extent of which in the common plane is greater than the extent in the direction perpendicular to the common plane.

6. The impeller blower assembly according to claim 5, wherein, The finger (104) begins at the distal end (106) and gradually tapers from the fastener (98) in the direction perpendicular to the common plane.

7. The impeller blower assembly according to claim 6, wherein, When measured within the common plane, the width of the finger (104) remains constant within the length range of the finger.

8. A combine harvester (10) having a straw shredder (60) and one or more impeller blower assemblies located downstream of the straw shredder (60), the one or more impeller blower assemblies being the impeller blower assembly according to any one of the preceding claims.

9. An impeller blade (84) adapted to be attached to the rotor of an impeller blower assembly for a crop residue chopping and distributing device for a combine harvester (10), characterized in that, The impeller blades (84) are made of ductile iron.

10. The impeller blade (84) according to claim 9, wherein the impeller blade is in the form of an integral finger rake, the finger rake including a fastening portion (98) at a proximal end, the fastening portion being detachably connected to the rotor cage or detachably connected to the rotor cage, and a plurality of fingers extending from the fastening portion to the distal end of the impeller blade (84).

11. The impeller blade (84) according to claim 10, wherein, The finger-shaped member (104) is located in a common plane and forms a finger-shaped rake.

12. The impeller blade (84) according to claim 11, wherein, The finger (104) and the fastener (98) are located in a common plane.

13. The impeller blade (84) according to claim 11 or 12, wherein, The finger (104) has a rectangular cross-section, the extent of which in the common plane is greater than the extent in the direction perpendicular to the common plane.

14. The impeller blade (84) according to claim 13, wherein, The finger (104) begins at the distal end (106) and gradually tapers from the fastener (98) in the direction perpendicular to the common plane.

15. The impeller blade (84) according to claim 14, wherein, When measured in the common plane, the width of the finger (104) remains constant within the length range of the finger.

Images