GB2057240A - Rotary combine - Google Patents

Abstract

A rotary combine and a method for threshing and separating crop are disclosed which utilize separate threshing and separating assemblies (27, 28). The assemblies are in the form of cylinders and the separating assembly is located transversely and rearwardly of the threshing assembly. Crop is introduced tangentially into the threshing assembly, conveyed by helical guide vanes (22, 23) to opposite end portions of the threshing assembly, passed from the threshing assembly axially into the separating assemblies and conveyed by a further series of helical guide vanes (34) to the rearward portion of the separating assemblies where the crop residue exits from the combine. <IMAGE>

Description

SPECIFICATION Rotary combine This invention relates to rotary combines.

In conventional combines, crop is threshed and separated by the use, in combination, of a threshing cylinder, a beater, straw walkers and a cleaner. Crop typically passes from a gathering mechanism through a table auger and a feeder elevator to the entrance portion of the threshing cylinderwhich is mounted transversely to the longitudinal frame axis of the combine. The threshing cylinder comprises a rotor rotatable within a concave and has metal rasp bars attached thereto to thresh the crop as it passes between the rasp bars and the concave of the thresh ing cylinder. A beater is positioned rearwardly of the threshing cylinder and its axis is substantially paral lel thereto. It further removes many of the free ker nels that have not yet been separated from the crop in the threshing cylinder and also directs the crop to the straw walkers.The straw walkers convey the crop residue to the rearward and exit portions of the combine while removing free kernels and grain heads which have not been previously separated from the crop. The cleaner is located below the straw walkers and comprises a chaffer located in a higher position and a sieve located beneath the chaffer. The chaffer allows the grain to drop therethrough and is adapted to remove the chaff because of its lighter weight and the effect of air flow. The chaffer also provides for returning grain heads to the threshing cylinder for rethreshing. The sieve allows the sepa rated free kernels to pass therethrough and be collected by a clean grain auger which conveys the grain to an elevator which, in turn, transports the grain to the grain storage tank.

The grain is removed from the grain tank by a grain auger located within an unloading chute which is located on one side of the combine. This chute allows grain to be removed from the grain tank to an unloading or receiving vehicle which is positioned on the side of the combine where the exit portion of the unloading chute is located.

Problems, however, are present in this conventional system. In typical applications, the concave surrounds the threshing cylinder for only a relatively small portion of the more than 360" which could be utilized to thresh and separate the crop. To increase the threshing ability of the combine, the rasp bars mounted on the threshing cylinder pass within a relatively small distance from the concave. The action of the metal rasp bars on the crop, however, can cause damage to the grain because of the in herent crushing and impact action due to the small distance between the rasp bars and the concave. In addition, rocks and other debris may find their way to the threshing cylinder and can jam the cylinder or damage the machine because of the rigid interface between the rasp bars and the concave.Further, the relatively small distance between the rasp bars and the concave limits the capacity of the threshing cylinder and as the crop feed rate of the combine is increased, substantial additional power is required to rotate the threshing cylinder against the increas ing amounts of crop which pass between the con cave and the rasp bars.

The straw walkers also have inherent problems.

As the capacity of the combine increases and, con sequently, the quantity of material passing therethrough also increases, the loss of efficiency of the straw walkers increases disproportionately to the increase in combine speed. Free kernels and grain heads escape from the combine without being sepa rated from the crop. This is obviously undesirable.

Recently, steps have been taken to reduce or eliminate many ofthese problems. Some manufacturers have attempted to reduce the damage to the grain caused by the rasp bars and to increase the efficiency of grain removal from the crop by utilizing "rotary" combines, so called because the crop circles the threshing and separating assemblies through one or more revolutions rather than passing over only a portion thereof. Because of the increase in threshing and separating ability, the distance between the rasp bars and the concave in rotary combines may be increased in orderto reduce the grain damage because the crop is subjected to a flailing action and the effect of centrifugal force as it travels around the periphery of the threshing and separating assembly.This is an improvement over the previously mentioned impact and crushing action which occurs between the crop, the rasp bars and the concave. A further benefit of utilizing the rotary combine with its increased separation efficiency is that the straw walkers may be eliminated. Nevertheless, some problems remain in these improved mechanisms.

The rasp bars continue to be used to obtain adequate threshing of the crop and, although the crushing action between rasp head and concave is reduced, some degree of impact continues. This dependence on rasp bars for threshing continues to cause some unnecessary damage to the grain.

Further, because there is more efficient threshing of the crop, the amount of chaff produced is increased.

This results in a great amount of dust and debris being produced at the entrance area of the threshing assembly and may create a large number of very short and light pieces of straw which makes baling difficult or impractical.

In some of these improved combines, the concave or grate may extend over 360" of the threshing cylinder. This increases the separation ability but also increases the quantity of very short and light pieces which results in the aforementioned baling difficulties.

Present rotary combine designs usually require the crop to be introduced axially to the threshing and separating assembly. Thus, the crop must necessarily turn through an angle which will allow the crop flow to match the angle of the helical guide vanes which convey the crop through the threshing and separating assembly. This requirement may cause The drawing(s) originally filed was/were informal and the print here reproduced is taken from a later filed formal copy.

unnecessary congestion at the entrance area and limit combine feed rate. This, in turn, adversely affects combine capacity.

Further, present conventional rotary combine designs usually call for the crop to travel a single path through the combine. In heavy crop conditions, this may also limit the feed rate of crop material, particularly at the entrance areas at the various assemblies, and this again limits combine capacity.

In either combine, conventional or rotary, the unloading chute is located on one side of the combine. There may be no or limited rotational adjust mentforthe unloading chute available to the operator in order to unload the combine, and at any rate, the combine must be unloaded on one side only. In normal crop combining applications, this may necessitate that the grain receiving vehicle drive through the swath thereby causing undesirable crop damage. It may also limit the unloading flexibility of the operator by creating unnecessary vehicle movement when two trucks are deployed.

More recently, some of these problems were overcome or substantially improved by the rotary combine disclosed and claimed in our U.S. Patent 4,117,849 (Pakosh). In the combine there disclosed, separate threshing and separator assemblies were utilized for greater efficiency which enabled complete elimination of the metal rasp bars. Crop was introduced not axially to the threshing and separating assemblies but rather along a plane substantially tangential to the entrance portion of the threshing cylinder. This enabled the combine to process a greater amount of crop because the angle of the helical guide vanes located on the upper half of the case was more closely aligned with the incoming angle of the crop thereby avoiding subjecting the crop to a large "turn" angle.A further improvement disclosed there was the introduction of crop at the central portion of the threshing assembly with the helical guide vanes on the case acting to split the crop upon its introduction to the threshing cylinder. This increased the capacity of the combine because dividing the crop allowed the machine to handle more crop in the threshing assembly.

While the combine disclosed and claimed in U.S.

Patent 4,117,849 went a considerable way towards solving some of the problems previously existing in rotary combines, further efficiencies and improvements were possible. It was found that the separation efficiency of the combine could be increased and the beater eliminated without compromising the combine's threshing ability by providing a separating assembly mounted with its longitudinal axis parallel to the longitudinal axis of the combine and passing the crop from the end portion of the threshing assembly directly into the entrance area of the separating assembly. Longitudinal placement of the separating assembly was preferred over transverse placement because of the increased area of the cylinder which can be utilized by allowing crop introduction axially through an end.Such an introduction technique allows the path length of the crop through the separating cylinder to be increased without increasing the size of the combine. Further, because threshing has already occurred, axial introduction to the separating cylinder does not create a condition where combine capacity is substantially affected.

A further improvement over that existing in previous combines is the positioning in the present combine of the unloading chute in the grain tank such that the exit portion of the unloading chute may be positioned on either side of the combine when unloading. This allows the operators of both the combine and the receiving vehicles greater flexibility in vehicle movement and helps prevent unnecessary and undesirable crop damage.

Yet a further improvement provided in the present combine is a forced air supply with a configuration which allows a supply of forced airto be blown over the grain pan. The provision of forced air acting to blow the lighter chaff from the grain and grain heads before they fall onto the grain pan increases the crop separation above that when air is blown only under the chaffer and sieve of the cleaner assembly.

Yet a further improvement provided in the present combine is a vacuum plenum surrounding a portion of the circumference of the threshing assembly. A vacuum is provided by the action of the separator assembly which creates a suction transmitted through the plenum to the entrance area of the combine. The suction reduces the incidence of blowing chaff and the other crop debris in the frontal crop introduction area.

In one aspect of the invention, there is disclosed a rotary combine for threshing and separating crop comprising: (a) crop feed means; (b) a threshing assembly mounted substantially transversely to the longitudinal axis of said combine; (c) entrance means in said assembly adapted to receive said crop from said crop feed means; (d) threshing guide means in said assembly to convey crop to an end portion thereof; (e) a first separator assembly mounted substantially transversely to said threshing assembly; (f) passage means in said threshing assembly at said end portion to allow passage of said crop to the entrance area of said separator assembly; and (g) separating guide means in said separator assembly to convey said crop rearwardlytherein.

In accordance with yet a further aspect of the invention, there is disclosed a method ofthreshing and separating crop, comprising the steps of: (a) receiving said crop substantially tangentially to the entrance portion of a threshing assembly; (b) threshing said crop while guiding it to a first end portion of said assembly; (c) passing said crop from the end portion of said assembly to the entrance portion of a separating assembly mounted substantially transversely to said threshing assembly; (d) separating said crop while guiding it to the rearwardly portion of said separating assembly; and (e) discharging the crop residue from said com bine.

In accordance with yet a further aspect of the invention, there is disclosed an unloading chute for a combine, said unloading chute having an entrance portion located adjacent the grain tank and an exit portion located outside the grain tank, said exit portion adapted to be moved from one side ofthe lon gitudinal axis of said combine to the opposite side whereby a loading vehicle may receive the grain from said combine from either of said two sides.

In accordance with yet a further aspect of the invention, there is disclosed an atmospheric clean ing device for a combine comprising: (a) a separator assembly; (b) an opening in the input end of said separator assembly; and (c) a plenum chamber communicating with the input end of said separator assembly and extending to the forward portion of said combine, whereby under operation of said separating assembly a suction is created in said plenum chamber to remove dust andlor debris from the atmosphere at said forward position of said combine.

The invention will now be described, byway of example only, with reference to accompanying drawings in which: Figure 1 is a side elevation of the rotary combine; Figure 2 is a rear view of the combine; Figure 3 is a cutaway plan view of the combine, not depicting the unloading chute; and Figure 4 is a plan view of the combine.

Referring now to the figures and with particular reference to Figure 1, a crop pickup 11 is located forward of the combine and may be one of several configurations for receiving the crop.

Atable auger 12 located in the table 13 and a feeder elevator 14, in turn, feed crop to the entrance area of the combine. These mechanisms are conventional and further description is not considered necessary. Athreshing unit generally denoted 15 is positioned with its longitudinal axis transverse to the longitudinal axis of the combine 1 and comprises a rotor 16 and a cylindrical perphery 17 surrounding the rotor. The rotor 16 has flexible blades 18 mounted thereon and, these are connected by fasteners (not shown) to the rotor 16. The cylindrical periphery 17 comprises a threshing cap 19 on the upper half of the cylinder periphery 17 and a concave 20 of conventional design on the lower half of the periphery 17.

Mounted within the threshing unit 15 on the upper cylinder periphery 17 are helical guide vanes 21 (Fig.

3). The several guide vanes are divided into right and left portions 22,23 respectively, each vane of which begins at the rearward portion 24 of the threshing unit 15 inwardly of the entrance area and extend to the left and right respective end portions.

Located with their longitudinal axes transverse to the longitudinal axis of the threshing unit 15 are first and second separating units 27,28, respectively. The separating units 27, 28 are substantially identical and, accordingly, only the first separating unit 27 will be described. A separating rotor 29 (Fig. 2) is mounted for rotation within the periphery 30 of the separating unit 27 and metal plates or blades 31 are mounted on the separating rotor 29. The periphery 30 of the separator unit 27 is formed of a solid cylindrical plate 32 over the upper half portion of the cylinder and a perforated grate 33 over the lower portion. Helical guide vanes 34 (Fig. 3) are mounted on the upper portion ofthe periphery 30 and extend from the entrance area 35 of the separating unit to the exit area 36.

The entrance area 35 of the separating unit has an open area below its longitudinal axis and a plate 60 (Fig. 1) mounted above the axis. An opening (not shown) is provided in the plate 60 and this opening communicates with plenum 61 which extends from the entrance area 35 of the separating assembly to the entrance area 62 of the threshing assembly 15.

The plenum is open at the entrance area 62 in the vicinity of elevator 14 and, at the rearward portion of the plenum 61, communicates directly with the opening in plate 60. An arrangement for controlling the size of the opening may be provided such as a mechanically or hydraulically operated sliding shutter valve (not shown).

Augers 44, 45, are mounted below separating assembly 27. Chaffer 38 is located below the rear ward portion ofthe grain pan 37 and is perforated with relatively large openings. A sieve 39 with relatively smaller openings is mounted below the chaffer.

A forced air supply 40 is mounted below the grain pan 37 to disperse air over the grain pan 37 and beneath the chaffer 38 and sieve 39. A centrifugal fan is provided to rotate within the housing ofthe forced air supply and two openings are provided to allow the necessary air to escape. The first opening 51 allows airto exit below the chaffer 38 and sieve 39 and the second opening 50 allows air to exit over the grain pan 37.

At the lower portion of the cleaning section, clean grain auger 41 is located. A second auger, return auger 43, is also located at the lower portion of the cleaning section but rearwardly of clean grain auger 41.

The grain tank 42 is mounted in the upper portion of the combine 1 and extends over and between the separator units 27,28 and the threshing unit 15. A first section 52 of the discharge or unloading chute generally denoted 46 extends from the grain tank 42 rearwardly to the junction of the first section 52 and the second section 53. The second section 53 extends upwardly and forwardly and terminates at the junction of it and the third section 54. The third section 54 extends forwardly and terminates in a grain exit means 55. Within each of the three sections, respectively, are grain handling augers 47,48, 49, which convey the grain from the grain tank 42 to the grain exit means 55. Suitable gear drives are provided to rotate the augers under power and to allow for rotation of the third section 54 of the discharge chute about the axis 56 (Fig. 4). Third section 54 is rotatable through an angle of approximately 270 as seen in Figure 4. In the area generally denoted 57, a screen 58 is provided about the top of the grain tank 42 to allow visual inspection by the operator of the quantity of grain in the grain tank.

In operation, swathed crop is received by crop pickup 11 and enters table auger 12 where it is conveyed from both sides towards the central portion and into feeder elevator 14. Feeder elevator 14 conveys the crop, in turn, to the central entrance area 62 ofthreshing unit 15 along a plane substantially parallel to the longitudinal axis of the rotor 16 of the threshing unit 15 and such that the crop smoothly enters the threshing unit 15 below its axis 63.

As the crop enters the threshing unit 15, the crop is subject to the initial threshing action of the flexible blades 18 over approximately 100" before it is divided by the guide vanes 22, 23 and conveyed to each side of the threshing unit 15, while continuing to be subjected to the flailing action ofthe flexible blades 18. A substantial portion of grain is removed from the crop in the threshing unit 15 and these free grain kernels pass through the concave 20 together with grain heads and some chaff onto the oscillating grain pan 37.

The threshed crop then passes from the exit areas of the threshing unit 15 axially into the separators 27, 28 below the centre portions. Since the action of both separators is substantially identical, only one will be described. The crop axially enters the entrance area 35 of separator 27 and is conveyed in a layer along the periphery 30 by the combined action of the helical guide vanes 34 and the rotor31. Grain remaining in the crop and, as well, grain heads and some chaff will pass through the grate 33 and fall downwardly into the augers 44,45. Augers 44,45 convey the grain, grain heads and any chaff which still remains to the forward portion beneath the separator where it drops towards grain pan 37.

Remaining material will exit from the separator 27 and be deposited on the ground.

As the grain, grain heads and chafffall downwardly from, respectively, the concave 20 of the thresher and the augers 44,45 of the separating units, they come under the influence of the cleaner generally denoted 59. Air exits at opening 50 to pass over the grain pan 37 and from opening 51 to pass through chaffer 38 and sieve 39 from the bottom upwardly. The action of the air from the forced air supply 40 blows the lighter chaff out the exit of the combine 1 while allowing the grain and grain heads to pass to the clean grain auger41 and return auger 43, respectively, through chaffer 38 and sieve 39. An elevator (not shown) conveys the grain from the exit of clean grain auger 41 to the grain tank 42. Grain heads which pass to return auger43 are conveyed to a rethresher (not shown) after which they are blown into separator unit 27.

The separators 27,28 also provide a suction for the plenum 61. The suction exists at the entrance at the area 62 of the threshing unit and acts to reduce the chaff and other debris by removing it from the atmosphere immediately forward of the threshing unit.

When the operator desired to unload the grain tank 42, he activates the augers 47, 48, 49 and directs the grain exit means 55, either by hydraulic means or otherwise, to either side of the combine, as may be desired. Grain then passes from the grain tank 42 to a truck or other transportation device which receives the unloaded grain.

Accordingly, there has been described a rotary combine which is illustrative of one embodiment of the invention. The description should not be construed as limiting the invention as many changes may be made without departing from the scope of the accompanying claims.

Claims (11)

1. A rotary combine for threshing and separating crop comprising: (a) crop feed means; (b) a threshing assembly mounted substantially transversely to the longitudinal axis of said combine; (c) entrance means in said assembly adapted to receive said crop from said crop feed means; (d) threshing guide means in said assembly to convey crop to an end portion thereof; (e) a first separator assembly mounted substantially transversely to said threshing assembly; (f) passage means in said threshing assembly at said end portion to allow passage of said crop to the entrance area of said separator assembly; and (g) separating guide means in said separator assembly to convey said crop rearwardly therein.

2. A rotary combine as claimed in claim 1 and further comprising a second separator assembly mounted substantially transversely to said threshing assembly and substantially parallel to said first separator assembly, said first and second separator assemblies being mounted with their respective entrance areas located adjacent respective end portions of said threshing assembly, said entrance means being located in the central portion of said threshing assembly, said threshing guide means in said threshing assembly acting to divide and convey said crop to said respective end portions.

3. A rotary combine as claimed in claim 1 or 2 wherein said threshing assembly is a cylinder and is adapted to provide relative motion between a rotor located therein and the circumference of said cylinder, said rotor comprising a drum with resilient flexible plates mounted thereon, said circumference including a concave located around substantially the entire bottom half of the periphery of said cylinder and a solid area located around substantially the entire upper half of the periphery of said cylinder, said threshing guide means comprising helical fins mounted on at least a portion of the circumference of said cylinder.

4. A method of threshing and separating crop, comprising the steps of: (a) receiving said crop substantially targentially to the entrance portion of a threshing assembly; (b) threshing said crop while guiding it to a first end portion of said assembly; (c) passing said crop from the end portion of said assembly to the entrance portion of a separating assembly mounted substantially transversely to said threshing assembly; (d) separating said crop while guiding it to the rearwardly portion of said separating assembly; and (e) discharging the crop residue from said combine.

5. A method as claimed in claim 4 and further comprising the steps of: (a) dividing said crop shortly after its entrance to said threshing assembly; (b) guiding a portion of said divided crop to a second end portion of said threshing assembly opposite said first end portion; (c) passing a portion of said crop from said second end portion of said threshing assembly to the entrance portion of a second separating assembly mounted substantially transversely to said threshing assembly and substantially parallel to said first separating assembly; and (d) separating said portion of said crop while guiding it to the rearwardly portion of said second separating assembly.

6. A method as claimed in claim 5 wherein said crop is at least partially threshed before dividing.

7. An unloading chute for a combine, said unloading chute having an entrance portion located adjacent the grain tank and an exit portion located outside the grain tank, said exit portion adapted to be moved from one side of the longitudinal axis of said combine to the opposite side whereby a loading vehicle may receive the grain from said combine from either of said two sides.

8. An unloading chute as claimed in claim 7 wherein there is at least one unloading auger between said entrance and exit portions, said auger acting to convey said grain from said grain tank to said exit portion whereby it may be received by said loading vehicle.

9. An unloading chute as claimed in claim 8 and further comprising at least one section extending from said grain tank to the outside of said combine and at least one further section extending from the outside end of said one section to the exit portion, at least one auger in said one section acting to convey grain from said grain tank to the end of said one section, at least one further auger in said further section extending from a position adjacent the entrance portion of said further section towards the exit portion of said further section and gear means between said one auger and said further auger.

10. An unloading chute for a combine comprising a first section extending rearwardly and substantially horizontally from said grain tank, a first auger in said first section adapted to convey grain from the entrance to the exit of said first section, a second section extending upwardly from the end of said first section to a position above the top of said grain tank, a second auger in said second section adapted to convey grain from the entrance to the exit of said second section, a third section extending forwardly from the exit of said second section to the forward portion of said combine, a third auger in said third section adapted to convey grain from the entrance to the exit of said third section, a gear box operatively mounted between said second and third augers and adapted to allow rotational movement of said third section relative to said second section and grain exit means mounted on the end of said third section, said third section being adapted for movement relative to said combine whereby an unloading vehicle may receive grain from said grain exit means on either side of said combine.

11. An atmospheric cleaning device for a combine comprising: (a) a separator assembly; (b) an opening in the input end of said separator assembly; and (c) a plenum chamber communicating with the input end of said separator assembly and extending to the forward portion of said combine, whereby under operation of said separating assembly a suction is created in said plenum chamber to remove dust and/or debris from the atmosphere at said forward portion of said combine.