Patent Application
20160227703
The invention concerns a roller segment for separating and cleaning devices, in particular of root crop harvesters, or similar sorting and cleaning devices of an agricultural machine in agricultural engineering, provided with at least one separating and cleaning stretch. With such a device generally usable in sorting and cleaning devices in agricultural engineering, potatoes that are to be separated from a mixture flow are separated from admixtures in particular during a lifting process.
The separating and cleaning stretch is provided with at least one roller that is assembled of one or several roller segments that in direction of a longitudinal roller axis are coaxially adjoining each other, wherein the roller segments are provided with a jacket part comprised of an elastically yielding material and comprising entrainment ribs projecting outwardly. The jacket part is interacting radially inwardly with a receiving area that is provided with recesses delimited by intermediate webs as well as with a through opening. The receiving area receives a polygonal shaft or similar drive element for torque transmission. The invention further relates to a method for manufacturing the roller segments of the aforementioned kind that are provided for a separating and cleaning device on root crop harvesters or similar devices of agricultural engineering and comprises an elastic jacket part.
In a device of the aforementioned kind for separating potatoes from admixtures in accordance with U.S. Pat. No. 5,775,435, rollers oriented transversely to the separating stretch are provided that are formed monolithically of elastically yielding material and therefore have a very high soft-elastic deformation capability. These rollers are connected to a drive in the area of a polygonal shaft penetrating through a central through opening so that the area which is located in circumferential direction above this through opening acts like an elastic jacket part with radially projecting entrainment ribs on the supplied mixture of soil and crop.
Based on the afore described roller construction, in a design according to EP 1 082 912 A2 it is provided that the rollers comprise a jacket part that is formed as a monolithic formed body with elastic properties. This jacket part which is comprised in particular of polyurethane is secured on a support body which is provided as an inner part and comprised of two identically shaped sheet metal parts. It is conceivable in this context that the support body in the area of the through opening surrounding the polygonal shaft of a drive is formed with an integral inner part so that the jacket part which is monolithic in cross-section comprises a special contour in the area of its inner part and, in this way, a more shape-stable fixation of the radially adjoining “elastic” jacket part is enabled.
According to EP 1 661 471 B1, the monolithic “jacket part concept” is improved in that now individual roller segments can be adjoined in a row in axial direction of the system. The jacket parts are formed in monolithic embodiment preferably of polyurethane and, in the area of a central through opening, can be pushed onto the appropriate polygonal shaft. The through opening in this context is delimited by two diametrically opposed angle members of sheet metal so that the stability for torque transmission is ensured.
In a separating device according to GB 2 432 097 A, similar to U.S. Pat. No. 5,775,435, monolithic rubber rollers with elastic outer profiles are provided, respectively. These rubber rollers also comprise in cross-section the central through opening and, at a spacing thereto, respective radial deformation chambers are formed so that different deformation properties for the respective separating process are made available.
It has been found that in the known monolithic embodiments of rollers or roller segments the use of long-term stable and sufficiently elastic polyurethane materials is required. Accordingly, high quality material is used that disadvantageously affects the manufacturing costs of the entire separating and cleaning device.
In a solution according to EP 2 223 587 B1, a variable elasticity in the area of a roller, similar to EP 1 661 471, is achieved in that, beginning at the comparatively shape-stable receiving area provided for the drive action, respective intermediate webs are extending to the outer jacket part. In the monolithically formed roller body an elastic tubular element that acts as an additional support means can be introduced in the area of the intermediate webs.
The invention concerns the problem to embody roller segments that are provided for separating and cleaning devices and a method for their manufacture in such a way that, for at least unchanged good separating and transfer functions, optimal deformation capability, and improved long-term stability of the rollers, their application-specific variable manufacture is possible more simply so that, as a whole, a reduction of the manufacturing costs is achieved.
The invention solves this problem with respective roller segments in that the respective roller segments, beginning at their inner through opening, are provided with a multi-layer structure in radial outward direction.
The invention solves this problem in regard to the method in that, beginning with a semi-finished product that can be produced as a formed core body with abutment profile, the semi-finished product is connected with a formed jacket body, comprising at least in some areas an elastic jacket part, to form a structure of at least two-layers as a component unit.
With regard to important further embodiments, reference is being had to the dependent claims.
Separating and cleaning devices for root crop harvesters or similar devices of agricultural engineering are using cleaning rollers that are in particular assembled of roller segments whose jacket part, provided in particular with outer entrainment ribs, can comprise variably designable soft-elastic deformation capabilities and properties in accordance with its cross-sectional configuration. The soft-elastic materials which can be used efficiently and with gentle action on the root crop entail however high manufacturing costs.
Based on the known embodiments of cleaning rollers with roller segments, the simplified concept according to the invention provides that the roller segments that, up to now, exhibit a monolithic elastomer configuration with zones of different stiffness or are formed with integrated stiffening metal supports as additional support means are formed of a multi-layer structure in an improved embodiment according to the invention.
Conceivable in this context is also to employ, instead of the roller segments assembled to a roller, a complete roller as a “monolithic part” with the multi-layer structure according to the invention. The manufacture of agricultural smooth rollers with multi-layer structure is also possible.
This multi-layer structure is defined respectively in that, beginning at the inner through opening of the roller segment, the roller segment in radial outward direction can be constructed of respective layers with variable layer thickness. In this context, it is provided that for this functional structure at least an inner layer, comprised of at least one comparatively inexpensive support material, and at least one jacket part top layer, having a comparatively minimal layer thickness and provided as a functional layer located on top and made of expensive deformation material, are combined. In this context, the manufacturing costs of such roller segments or rollers can be advantageously reduced.
The system according to the invention is designed such that the roller segment has preferably only a two-layer structure which is provided with a first layer that forms the through opening and a second layer, correlated therewith radially, as an elastic jacket part. Advantageously, a structural configuration can be designed that makes additional metal structures, support layers or similar support means of known roller segments expendable.
It has been found that the at least two layers of the roller segment in this context can be formed advantageously of different plastic materials. These two plastic materials in regard to their elasticity-stiffness ratio are optimally matched relative to each other. In this way, it is achieved that, on the one hand, a driving torque is immediately and reliably transmittable onto the inner layer of the two-layer segment that is forming the receiving area for a drive element and, on the other hand, the outer layer as a functional jacket part comprises a structure which is matched to the specific conditions of use.
An optimal configuration of the roller segments that are functionally optimizable in the area of the two plastic material layers provides that its inner layer in radial cross-section is in the form of a formed core body that comprises at least a circumferentially arranged abutment profile. This formed core body which is comprised of a comparatively bending-stiff material has correlated therewith a formed jacket body that defines the outer “elastic” layer. In this context, the two-layer structure in the connecting area of abutment profile and counter profile of the formed jacket body is connected such that the latter, in use of the roller in the functional state of the system, comprises a generally known rotational fixation in the two-layer composite.
It is understood that for this abutment profile/counter profile connection, variable cross-section contours can be used in accordance with the roller concept. Based on the dimensions of the roller segment, different engagement lengths of the respective connection profiles are conceivable in radial direction and a variable number of afore described profile connections are possible in circumferential direction of the roller segment.
It has been found that based on the inner formed core body that is effective as a comparatively shape-stable structure in the cross-section of the roller segment, the formed jacket body, which forms together with the formed core body a component unit and that is a layer that can be varied in regard to thickness, enables respective combinations of the layers with very different dimensions. In this context, the formed jacket body, in particular in radial direction, can define an outer functional area of the roller segment that is dimensionally variable by manufacturing technology and in this context is comprised, at least in some areas, of the elastic material so that different root crop harvesters can be matched to the respective crop in this way. The roller segments can be provided in this context at the outer circumference with entrainment profiles which, as functional partial areas, are known in general.
An optimally designed realization of this two-layer component unit provides that the formed core body is provided as a pre-manufactured semi-finished product and the latter is assembled with the formed jacket body, correlated therewith at least in some areas, to the unit that is constructed of the at least two different materials. With regard to the use of the roller segment, it is understood that the formed jacket body is designed as an elastic envelope body which surrounds completely in circumferential direction the formed core body and comprises in particular the “deformation areas” that utilize the inwardly oriented compensation movements in the radial direction.
Based on the concept according to the invention of the two-layer structure, it is provided that between the formed core body and the formed jacket body in the area of the respective abutment/counter bearing profiles different options for manufacturing the component unit are conceivable. In this context, it is provided that, at least in some areas, respective material-fused, friction-connected and/or form-fit connecting zones are formed.
The embodiment of the two layer system according to the invention provides also that the formed core body itself and/or the formed jacket body itself can be formed of several materials, respectively. Preferably, in this context different combinations of plastic materials are in principle conceivable so that the material-specific manufacturing costs are correspondingly variable.
In accordance with the purpose of use, it is provided that the respective formed core body is formed of a material that, in relation to the respective material characteristics, has at least a greater stiffness than the formed jacket body. With regard to manufacturing costs, it is provided that the formed core body that is comparatively greater particularly with regard to its volume is produced of a material which is less expensive based on cost comparison.
Extensive tests on prototypes for realizing the two-layer roller segments have shown that the component unit advantageously enables a formed core body made of thermoplastic material, thermosetting plastic material and/or glass fiber reinforced plastic material. It is combined according to the invention with a formed jacket body which is formed at least in some areas of soft-elastic plastic material or rubber. This formed jacket body is comprised preferably of polyurethane, thermoplastic polyurethane, or thermoplastic elastomer.
The concept realization of the abutment profile which is radially outwardly projecting away from the formed core body provides that it is preferably formed as a partial section of a thread profile provided with a pitch. Accordingly, the formed core body is shaped like a “spiral core”. An effective connection for this “ascending” abutment profile is provided in that it engages a receiving groove of matching shape that is provided on the inner side of the correlated formed jacket body so that, in this way, at least a form-fit connection of the two layers is formed.
In this connecting position of the formed core body and of the formed jacket body, a deformation structure formed with essentially known free spaces results in longitudinal direction of the connected bodies in the near area of the connection profiles extending as “intermediate webs”. In accordance with the configuration of this deformation structure delimited by the connection profiles, a variable configuration of the roller segment with regard to its elastic deformation properties can be achieved. In this context, the also “spiral-shaped” extending entrainment profiles are formed radially outwardly, adjoining the free spaces.
In this way, it is apparent that different embodiments of the elasticity system are conceivable by means of the afore described combination of connection profiles and deformation structure. In particular, the free spaces which are extending between the support connections extending in a coil shape can be variably dimensioned in radial direction of the deformation structure. These free spaces which are extending in a coil shape in longitudinal direction of the formed jacket body can form in cross-section an angular or round channel structure. Also, additional longitudinal and/or transverse ribs are conceivable within the deformation structure.
A configuration in the area of the formed core body that is important for the strength of the afore described connection configuration provides that their radially projecting abutment profiles each are formed as “coiled” strip profiles with top-side expansion projection. In this context, the strip profiles, in turn, are provided with respective transverse openings so that in this area, in addition to the radial engagement of the abutment profiles by the formed jacket body in the area of the expansion projections, respective tangential connection areas become utilizable. In this context, it is understood that with the afore described connection profiles, on the one hand, different tensile and compressive loads can be absorbed that in use of the roller are introduced from the outer functional area of the formed jacket body into the system and, on the other hand, the drive torque in the area of the central through opening can be optimally introduced into the two-layer structure.
In an advantageous embodiment of the formed core body, a contour that delimits it as a profile frame is formed in the area of the through opening. Beginning at the through opening, respective projecting webs extending toward an envelope cylinder part are oriented outwardly in radial direction. Several of the coiled strip profiles are provided, in turn, on its outer circumference. Accordingly, with comparatively minimal material expenditure, a formed core body can be produced that in cross-section is essentially embodied as a “framework of lightweight construction”.
A conceivable variant of the multi-layer structure provides that the latter comprises a “third” additional layer interacting with the formed core body in the area of the central through opening. In this context, this additional layer can be comprised of metal. Also, it is provided that the additional layer that is comparatively “thin” in regard to its material thickness can be made of plastic material. In this context, a material with elastic and thus vibration-damping characteristic values is conceivable.
For producing the afore described component unit of the two layers in the area of the correlated profiles, the manufacture of a form-fit connection by appropriate compression of the two layers of the structures is in principle conceivable. A preferred embodiment provides that in the area of the connection profiles a fused material connection is generated. This can be realized preferably by dead-mold casting that is dependent on the material properties of the two layers. Also, it is conceivable that an adhesive connection is combined with a friction connection in the area of the connection profiles.
For producing this roller segment provided for a separating and cleaning device, a multi-step process sequence is provided in particular. In this context, in a first process step a formed core body with abutment profile is produced as a semi-finished product. The latter can then be completed to the two-layer structure as a component unit by means of a formed jacket body that comprises at least in some areas the elastic jacket part.
A conceivable variant provides that the formed core body and the formed jacket body are provided as respective semi-finished products comprising complementary connection profiles. These two semi-finished products can then be connected by appropriate plug-in and/or pressing methods by a friction connection and/or form-fit connection in such a way that at least the connection stability that is required in circumferential direction between the two “individual parts” of the two-layer system during use in the roller is ensured.
The optimal embodiment of the connecting process provides however that the two-layer structure is produced by a fused material connection that is provided at least in some areas between the formed jacket body and the formed core body. Based on generally known manufacturing phases, it is provided according to the invention that the formed jacket body is generated by a casting process that encloses at least in some areas the formed core body and, at the same time, in addition to a form-fit connection, a fused material connection between the two layers of the structure can be produced.
Also, it is conceivable that the two-layer structure of the component unit can be generated by an injection molding process.
Based on the material properties of the materials used for the two layers, connection combinations can be produced in this context which comprise, in functionally relevant fused material connecting zones, layer or penetration structures that are variable in accordance with the process parameters. In this process phase with a layer-composite manufacture of the roller segment, the geometrically variable configuration of the two components forming the layers is also to be taken into consideration because a respective optimization of the process parameters is also conceivable based on the geometric shapes.
An expedient embodiment of the process control provides that the two-layer roller segments are produced by a casting process in a casting mold. In this context, the pre-shaped formed core body is inserted as a semi-finished product into the casting mold such that a casting zone remains that is to produce the formed jacket body. This casting zone is subsequently filled with the liquid elastomer plastic material. Subsequent to a material-specific hardening phase, the roller segment can then be removed from the casting mold as a two-layer component unit.
In accordance with the afore described process sequence, it is conceivable that during the casting process a stabilizer is introduced into the formed core body that stiffens the central through opening. It is likewise conceivable that in place of a one-piece embodiment of the casting mold a multi-part component group is used or the two plastic materials are simultaneously or sequentially introduced into a casting mold that is to be appropriately adjusted and, in this way, the complete roller segment is produced in one process sequence.
A further process control for fused material connection of the two components pre-manufactured as layers provides that the formed jacket body can be connected with the formed core body also by a vulcanization process that is carried out at least in some areas.
Further details and advantageous embodiments of the invention result from the following description and the drawing in which the embodiment of the separating and cleaning device according to the invention with respective roller segments as well as a device for their manufacture are illustrated.
In
A separating and cleaning stretch 4 (
In this context, the roller segments 1 in already known embodiment are provided with a jacket part 8 that is made of an elastically yielding material and comprises outwardly projecting entrainment ribs 7. This jacket part 8 in the construction according to EP 1 661 471 B1 is provided at its inner side with a receiving space that comprises recesses delimited by intermediate webs, a central through opening 10 as well as support means. This area of the through opening 10 is shaped such that preferably a polygonal shaft or similar drive element 11 (
Based on the plurality of already known constructions, similar to the roller segment according to
It has been found that an optimal embodiment of the roller segment 1 is already useable when it is comprised of only the two-layer structure with the layers B and C. The first layer B forms in this context the through opening 10 and this first layer B has correlated therewith the second layer C as the radial elastic jacket part.
For an efficient technically and economically improved realization of the two-layer roller segment 1 according to the invention, it is provided that it is comprised of different materials, i.e., two optimally combinable plastic materials. In this way, for the first time a construction of a roller segment 1 is realized that is free of support metals or similar additional support means within this layer composite. A surprisingly effective segment for different construction variants is provided on this basis. Based on the function-relevant properties of known elastic jacket parts 8 as layer C (
Based on the following overview illustrations of
The constructive realization of the roller segment 1 provides that based on the inner formed core body 13, formed as a comparatively shape-stable substrate, the formed jacket body 15 forming a component unit therewith is to be dimensioned such that the formed jacket body 15, at least in radial direction, forms a functional area that is variable by manufacturing technology in its dimensions with a cross-sectional profiling that can be adjusted with regard to the conditions of use of the cleaning device 3. In this context, the formed jacket body 15 is at least in some areas formed of the generally known elastic material with which application-specific deformation areas and thus adjustments are possible in regard to the bulk material, fruits or similar transportation goods to be processed on the separating stretch 4.
The illustrations according to
The envelope contour of the formed jacket body 15 which is marked in
Based on the preferred configuration of the component unit E with several of the abutment profiles 12 and counter profiles 14, a variable manufacture of the load-stable layer composite of the layers B and C is conceivable. In this context, different manufacturing technological variants are realizable wherein at least in some areas respective fused material, friction connected and/or form-fit connecting zones can be generated during the manufacture of the component unit E. This plurality of connections can also be expanded in that the formed core body 13 and/or the formed jacket body 15 are constructed and formed of several materials, in particular respective plastic material layers.
An important goal of the invention with regard to the use of the roller segment 1 (
This cost-optimized embodiment of the component unit E provides that the formed core body 13 comprised of thermoplastic material, thermosetting plastic material and/or glass fiber reinforced plastic material is combined with a formed jacket body 15 that is comprised at least in some areas of soft-elastic plastic material or rubber. The formed jacket body 15 forms in this context a layer B which is preferably made of polyurethane (PUR), thermoplastic polyurethane (TPU, TPE, TPO, TPV, TPC) or thermoplastic elastomer (TPS, TPA).
The perspective illustrations according to
From the section illustrations according to
The constructive configuration in this area provides also that the free spaces F, extending in longitudinal direction of the formed jacket body 15 in a coil shape and comprising a bottom layer BS covering the formed core body 13, can define variable cross-sectional structures. In this context, it is provided that the free spaces F can form one or several partial areas which in cross-section comprise respective angular and/or round boundary contours. Also, it is conceivable that in the area F further partial webs are extending so that the free spaces F are divided (not illustrated in detail).
The formed core bodies 13 illustrated in
Based on the formed core body illustrations shown in front view and rear view according to
Based on the front views of
When looking at
In
Based on the afore described roller segment 1, 1′, 1″ with the multi-layer structure B, C according to the invention illustrated in detail in
Based on a semi-finished product H (
A further variant of the manufacturing process for connecting the two layers B and C provides that at least in some areas between the formed jacket body 15 and formed core body 13 a fused material connection is produced. This fused material connection can in principle be embodied as an adhesive connection so that also a combination with the afore described friction connection and/or form fit connection variants is conceivable.
A preferred embodiment for producing the roller segment 1 according to the invention provides that a connecting technology on the basis of a casting process is utilized. In this context, the formed jacket body 15 can be generated by a casting or injection molding process that at least in some areas encloses the formed core body 13. In this case, simultaneous with the casting process also a fused material connection between the two layers B and C of the structure is produced (
From the overview illustrations according to
In direction of arrow X (
The afore described casting process P can be improved in regard to filling in the liquid plastic material in that an additional stabilizer (not illustrated) is introduced into the system. Also, it is conceivable that in place of the illustrated one-part mold 25 a multi-part, in particular divided, embodiment is used so that, if need be, the removal (arrow R′) is simplified because in this phase only the inner profilings in the area of the cores KF and the support pin 29 are effective.
A further variant of the process control for fusing the layers B and C provides that the component unit E of formed jacket body 15 and formed core body 13 can also be produced by a vulcanization process (not illustrated) realizing vulcanization at least in some areas.
In
The section illustration according to
The specification incorporates by reference the entire disclosure of German priority document 10 2015 101 900.0 having a filing date of Feb. 10, 2015.
While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2015 101 900.0 | Feb 2015 | DE | national |
