Easy assembly separator for combine harvesters

A self-propelled combine harvester has an axial-flow separating device including a chopping device with supporting rings which carry impact teeth. The main body of each separating rotor is equipped with several positioning profiles, which are rigidly connected to the main body and extend spirally around it. The supporting rings are provided with corresponding grooves. As a result, a form-locking connection is made between the supporting rings and the main body. The positioning profiles are toothed at the longitudinal edge leading in the direction of rotation of the separating rotor, so that the regions of the supporting rings adjoining the recesses engage in the tooth gaps are prevented from sliding axially. A locking ring is releasably mounted on the rear end of the main body. The number of parts is minimized and the construction of the supporting rings carrying the impact teeth and the main body of the separating rotor minimize the assembly time.

BACKGROUND OF THE INVENTION
 The present invention relates generally to agricultural machinery and, more
 particularly to improvements in separators for combine harvesters for
 agricultural crops.
 The invention concerns a combine harvester with a cutting bar and a sloping
 conveyor, which transports the cut material away. A tangential or axial
 thresher is mounted behind the sloping conveyer, which is followed in the
 direction of flow of material by at least one separating device. The
 separating device works by the axial-flow method and comprises at least
 one drivable separating rotor which is rotationally surrounded by a
 housing. Over a certain conveying distance, the drivable separating rotor
 is constructed as a chopping device for the straw and cooperates with
 chopping blades. The cylindrical main body of the separating rotor carries
 several rows of impact teeth which extend in the longitudinal direction,
 preferably helically or arcuately, and which are arranged on supporting
 rings spaced apart from one another.
 The combine harvester in question is particularly suitable for harvesting
 cereal grain. After threshing out the grain with the thresher it is
 necessary to separate out the grain from the grain and straw mixture. The
 separating device here, which works by the axial-flow method, ensures
 continuous transport of the straw around the separating rotor. This is
 achieved by the helically or spirally extending conveying elements, such
 as conveying strips for example, in cooperation with guide webs in the
 rotor housing. The guide webs can run parallel to and at a distance from
 the axis of rotation of the separating rotor or likewise be arranged
 helically or spirally. Usually the separating rotor is equipped with four
 conveying elements which are each respectively offset from one another by
 an angle of 90 degrees and arranged in rows. The outer edges of the
 conveying elements, which are constructed as conveying strips and whose
 edges face away from the axis of rotation are sawtooth-shaped. Most
 combine harvesters are equipped with a chopping device for the straw which
 can be used selectively, depending on whether the straw is to be deposited
 in swathes or is to be distributed as chopped material over the harvested
 field surface. The separating rotor of the separating device, which works
 by the axial-flow method, can work opposite the direction of forward
 travel of the combine harvester or transversely thereto. In the former
 case, the axis of rotation of the separating rotor is transverse and in
 the latter case the axis of rotation is parallel and at a distance from
 the wheel axles of the combine harvester.
 A combine harvester in European patent publication 0 748 583 A1, shows a
 main body of the separating rotor in the region of the chopping device
 which has a smooth surface. In order to chop the straw, it is equipped
 with a plurality of supporting rings which are spaced apart from each
 other. These supporting rings carry the impact teeth on the
 circumferential side. It can be seen from this patent that the supporting
 rings are fixed to the main body of the separating rotor by a welded
 connection or screw connection. Such connecting techniques known in the
 art however cause the assembly time to be extremely long. As the impact
 teeth are regarded as wearing parts, after an operating time which cannot
 be determined exactly, it becomes necessary to exchange the supporting
 rings with the impact teeth. The time for dismantling and for subsequent
 assembly is extremely long. Moreover, the possibility of the impact teeth
 being damaged, for example by foreign bodies, exists. Thus, either all the
 supporting rings or only some may have to be exchanged. Thus, the
 prior-art construction is not particularly maintenance and
 assembly-friendly and, due to the long assembly times, can be relatively
 cost-intensive.
 German patent publication 197 20 074 A1 proposes that the impact teeth of
 one row form a single-piece impact tooth functional part which is
 releasably attached to the main body of the separating rotor. Filler
 bodies, which are provided with cutting grooves for the chopping blades,
 are arranged between the rows of impact teeth. The filler bodies located
 between two rows of impact teeth are constructed in one part and also
 releasably attached to the main body of the separating rotor or to an
 adjoining impact tooth functional part. German patent 197 20 074 A1 also
 presents a solution in which each impact tooth functional part and the
 filler body behind it in the direction of rotation are also in one part.
 However, this solution also requires significant assembly time, so that
 this proposed solution also cannot be structurally converted.
 It is an object of the present invention to overcome one or more of the
 above-described difficulties.
 Another object is to provide a combine harvester having a separator which
 is structurally simple, thus significantly simplifying the assembly of the
 supporting rings of the chopping device.
 SUMMARY OF THE INVENTION
 In accordance with the present invention there is provided a combine
 harvester having a cutting mechanism; an elevating conveyor for
 transporting the cut material; a threshing mechanism mounted behind the
 elevating conveyor; an axial-flow separating mechanism for separating
 grain from straw; and the separating mechanism being mounted behind the
 threshing mechanism and comprising at least one drivable separating rotor
 surrounded by a housing, a chopping device for the straw over a certain
 conveying distance and cooperating with chopping blades, and the
 separating rotor including a cylindrical main body carrying one or more
 rows of impact teeth extending in the longitudinal direction and which are
 arranged on spaced supporting rings; the main body of each separating
 rotor having a plurality of positioning profiles fixed thereto; the
 supporting rings corresponding to the rotor circumference being provided
 with at least a number of recesses corresponding to the number of
 positioning profiles; and means for securing the supporting rings and the
 positioning profiles in form-locking relationship to prevent turning and
 axial sliding.
 The object of the present invention is achieved by equipping the main body
 of each separating rotor with at least one positioning profile fixed
 thereto, providing the holes of the supporting rings corresponding to the
 rotor circumference with a number of recesses which correspond to the
 number of positioning profiles, and fixing the supporting rings to the
 positioning profiles in form-locking relationship, thus preventing the
 supporting rings from turning and sliding axially.
 According to one embodiment of the invention, it is not absolutely
 necessary to fix the supporting rings by mechanical connecting elements,
 such as bolts or by welding seams to the main body. The positioning
 profiles provide a push-fit system since, starting from the front side,
 the supporting rings with the impact teeth arranged thereon can be fitted
 on the main body successively. If occasion arises additional elements can
 be assembled, depending on the type of form-locking connection. The
 positioning profiles are to be regarded as a template by which the
 position of the impact teeth and supporting rings is predetermined. A
 releasable connection is provided between the main body and the supporting
 rings. The grooves of the supporting rings are sufficiently wide such
 that, even with a helical or curved path of the positioning profiles, the
 supporting rings can be properly fitted to the main body. Various elements
 can be used for the form-locking connection of the supporting rings to the
 main body. The design according to the invention only requires fitting a
 locking ring onto the rear end of the separating rotor in the direction of
 transport and in the region of the chopping device.
 In a further embodiment of the present invention, it is provided that the
 positioning profiles at a longitudinal edge comprise teeth, that the
 regions of the supporting rings adjoining the recesses lie in the tooth
 gaps of the teeth and that a spacer or distance ring is provided between
 two supporting rings, which on one side face comprises clamping elements
 which engage in form-locking relationship in the free partial recesses of
 the supporting rings resulting from the tooth gaps of the positioning
 profiles, thereby closing them.
 The form-locking connection is simplified by the teeth between the
 positioning profiles and the supporting rings. Axial locking is made
 possible by the regions of the supporting rings adjoining the recesses
 engage in the tooth gaps. The clamping elements engaging in the recesses
 results in locking against rotation. As these clamping elements are in one
 piece with the distance rings, at the same time the distance between the
 supporting rings is predetermined. The positioning profiles and the
 distance rings can be constructed easily with the applicable manufacturing
 techniques even if the positioning profiles extend arcuately or helically.
 With this construction it is also unnecessary to use tools when changing
 the supporting rings after removal of the end locking ring. It is also
 advantageous when the clamping elements are wedge-shaped and formed
 integrally on the front side face of each distance ring. The wedge-shaped
 design provides an insertion aid for fitting in the recesses. Moreover
 means to prevent rotation without play is provided. In the simplest design
 the teeth consist of alternately arranged rectangular teeth and
 corresponding tooth gaps. Due to the rectangular construction of the tooth
 gaps, there is a large area of contact of the regions of the supporting
 rings adjoining the recesses with the surfaces defining the tooth gaps. In
 order for the supporting rings to be pressed into the tooth gaps by the
 forces arising in the operative state, it is provided that the teeth, seen
 in the direction of rotation of the separating rotor, are provided at the
 leading longitudinal edge of each positioning profile. The forces are then
 transmitted via the positioning profiles to the main body. Here an
 advantageous distribution of these forces is achieved if the main body is
 provided with four equiangularly spaced-apart positioning profiles and the
 supporting rings are provided with corresponding recesses.
 According to yet another embodiment of the present invention, it is
 provided that the positioning profiles in cross-section are flat profile
 sections and that the supporting rings in cross-section are angle-shaped.
 Furthermore, the impact teeth are attached to the circumferential surface
 of larger diameter and the widths of the recesses of the supporting rings
 essentially correspond to the width of the positioning profiles. The
 attachment which is kept smaller in diameter then has the function of a
 distance ring. This construction advantageously reduces the number of
 components compared with the previous design. The widths of the recesses
 must be selected in such a way that, in the radial direction there is a
 secure connection of the supporting rings to the main body. The smaller
 attachment which determines the distance between the impact teeth can be
 arranged on both the front and the rear sides of the supporting ring. With
 this construction too, locking in the axial direction is achieved by a
 locking ring mounted releasably on the end of the main body. However, in
 order for there to be locking in this direction without play, it is
 provided that several pressure screws, working in the axial direction, are
 screwed into the locking ring. The locking ring is equipped with at least
 one impeller paddle on its outer surface for the purpose of promoting the
 discharge of material at the rotor end.

DETAILED DESCRIPTION
 The combine harvester shown in FIG. 1 is designed as a self-propelled
 combine harvester 1 equipped with a separating device which works by the
 axial-flow method and which contains at least one rotatable separating
 rotor 3 which is surrounded by a housing 4. This housing 4 consists of an
 upper portion in the form of a hood 5 and a lower portion in the form of a
 separating cage 6. In the embodiment shown in FIG. 1, the axis of rotation
 of the separating rotor 3 lies transversely to the wheel axles of the
 wheel pairs 7, 8 of the combine harvester 1. Consequently the direction of
 conveying of the separating rotor 3 is opposite the direction of forward
 travel of the combine harvester 1. Moreover, the separating rotor 3 is
 provided with four conveying strips 9 which form the conveying elements
 extending helically around the main body 10, as shown in FIG. 4. The
 combine harvester 1 is further equipped with a blower 11 located below the
 separating rotor 3 and a screen device 12 also located below the
 separating rotor 3. Moreover the combine harvester 1, in a manner known in
 the art, is equipped with a cutting table, not shown, and a sloping
 conveyor 14 which conveys the cut material to a thresher. All these
 elements are rather unimportant to the invention and can be altered as
 desired.
 In the embodiment shown in FIG. 1, the thresher 13 consists of a threshing
 drum 15 and a transfer drum 16, which is mounted directly in front of the
 feed end of the separating rotor 3 and transversely to its axis of
 rotation. Furthermore the combine harvester 1 is also equipped with a
 generally known distributor 17 for the chopped material. As FIG. 1 shows,
 the rear end region of the separating rotor 3 is equipped as a chopping
 device.
 In the embodiments shown the main body 10 of the separating rotor 3, which
 is approximately annular in cross-section and rather smooth-surfaced on
 the outside, is equipped in the region of its rear end with four
 preferably helically, spirally or arcuately extending positioning strips
 18 which are in each case parallel and offset from each other at an angle
 of 90.degree.. The basic cross-sections of the positioning strips 18 are
 rectangular and relatively thin. The positioning strips 18 are rigidly
 connected to the main body 10 of the separating rotor 3 for example by
 welding or by bolting. A plurality of spaced-apart supporting rings 19
 which, according to the embodiments shown, are equipped with four impact
 teeth 20 at distances of 90.degree. from each other, are mounted on the
 main body 10 of the separating rotor 3. In an advantageous embodiment the
 supporting rings 19 are in one piece with the impact teeth. The supporting
 ring holes are provided at their circumference with recesses adapted to
 the positioning strips 18.
 In the embodiment according to FIGS. 3 to 5, the positioning strips 18 on
 the front longitudinal side in the direction of rotation A of the
 separating rotor 3 are provided with teeth which are formed from
 rectangular teeth 21 and corresponding tooth gaps 22. As shown in
 particular by FIG. 5, after s fitting the supporting rings 19 on the main
 body 10 of the separating rotor 3, the supporting rings 19 are moved in a
 direction opposite the direction of rotation A of the separating rotor 3,
 so that the regions adjoining the recesses engage in the tooth gaps 22. As
 a result, form locking is achieved between the supporting rings 19 and the
 main body 10 of the separating rotor 3. This form locking is secured by
 clamping elements 23 in the form of wedges which engage in the partial
 recesses 24' formed by rotation of the supporting rings 19. The clamping
 elements 23 are attached to spacer or distance rings 25 which are located
 between the supporting rings 19.
 In the embodiment according to FIG. 6 the cross-section of each positioning
 strip 18 corresponds to that of a flat steel bar. The recesses 24 of the
 supporting rings 19 are selected such that they can be fitted on the
 positioning strips 18 in closing relationship. By contrast to the
 construction best shown in FIGS. 4 and 5, the supporting rings 19 are
 angle-shaped, so that the distance between the impact teeth 20 is
 predetermined by the attachment 19' of smaller diameter attached to the
 supporting ring 19. In both constructions a form-locking connection, which
 is free from connecting elements, is achieved between the supporting rings
 19 and the main body 10 of the separating rotor 3. A locking ring 26 is
 releasably fitted on the rear end of the main body 10, in the direction of
 conveying the straw, which in its simplest construction is prevented from
 sliding by radially screwed-in locking screws 27. This ensures that the
 spacer or distance ring 25' mounted as a closure of the assembly group
 cannot come loose in the construction according to FIG. 3. In the
 construction according to FIG. 6 the supporting rings 19 are prevented
 only from turning by the positioning strips 18. Thus, it is provided that
 according to FIG. 7 the locking ring 26 is additionally provided with
 several pressure screws 28 working in an axial direction. As a result, the
 distance rings 25 or the supporting rings 19 are firmly pressed against
 one another. A pressure disc 29 is provided between the last supporting
 ring 19 and the locking ring 26 to distribute the compression forces
 applied by the pressure screws 28. The locking rings are provided at their
 outer circumference with impact plates 26', which are present at least
 according to the division of the impact teeth 20. The effect of these
 impact plates 26' is favorable for discharge of the chopped material.
 FIGS. 2 to 7 show that the connection of the supporting rings 19 to the
 main body 10 of the separating rotor 3 is also constructed as a push-fit
 system, so that mechanical connecting elements are eliminated here too. It
 can also be seen that assembly, dismantling or exchange of various
 supporting rings can take place within an extremely short time. FIGS. 3
 and 4 also show that the main body 10 of the supporting rotor 3 is
 equipped with an input cone 30 on which is supported and centred the first
 supporting ring 19 in the direction of flow of material. Due to the input
 cone 30, a transition is made without attachments between the main body 10
 of the separating rotor 3 and the higher working plane of the supporting
 rings 19. FIG. 2 also shows that the annular gap between the separating
 rotor 3 and the housing 4 in the region of the separating cage 6 is
 decreased in relation to the hood 5. However, a smooth transition can also
 be made, for example by a reduced diameter of the separating rotor 3 in
 this region.
 The invention is not confined to the embodiments shown. An essential point
 is a form-locking connection of the supporting rings 19 carrying the
 impact teeth 20 to the main body 10 of the separating rotor 3 without
 mechanical connecting elements or weld seams being necessary for this. It
 is also important that no special tools are required for assembly of the
 supporting rings 19.
 The distribution of the impact teeth 20 on the rotor main body is
 determined by the form of arrangement of the positioning strip or several
 positioning strips. Alternatively it is possible to provide the inner edge
 of each supporting ring hole with a plurality of latch-in recesses,
 thereby creating a choice of various possible arrangements of impact teeth
 on the rotor and allowing for one or more positioning strips to be
 arranged with axes parallel to the axis of rotation of the rotor.
 As FIG. 2 shows, chopping blades 31 comprising cutting edges are arranged
 between the impact teeth 20. By means of an actuating mechanism 32 which
 can be operated from the driver's cab, the chopping blades 31 can be
 pivoted from the operating position shown in FIG. 2 and into a rest
 position. The chopping blades 31 are fixed to blade holders 33 and
 therefore can be used in such a way that one or the other cutting edge can
 be used selectively.
 Other objects, features and advantages will be apparent to those skilled in
 the art. While preferred embodiments of the present invention have been
 illustrated and described, this has been by way of illustration and the
 invention should not be limited except as required by the scope of the
 appended claims.