Abstract:
The present invention relates to a rotor box for a ground milling machine, in particular for a road milling machine or a trench milling machine, having at least one milling roller accommodated therein for loosening and/or removing soil material. It is provided that at least one guide device is arranged in the interior of the rotor box, which, in cooperation with the rotating milling roller causes a conveyance of the loosened milled material in the axial direction (L) of the milling roller or at least supports such a conveyance. The present invention also relates to a ground milling machine, in particular a road milling machine or trench milling machine, which has at least one such rotor box.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority under 35 U.S.C. §119 of German Patent Application No. DE 10 2011 009 092.4, filed Jan. 21, 2011, the disclosure of which is hereby incorporated herein by reference in its entirety. 
       FIELD OF THE INVENTION 
       [0002]    The present invention relates to a rotor box for a ground milling machine, having at least one milling roller (or milling rotor) accommodated thereon, which is provided for loosening and/or removing soil material. Furthermore, the present invention relates to a ground milling machine, such as a road milling machine or a trench milling machine in particular, which has at least one such rotor box. 
       BACKGROUND OF THE INVENTION 
       [0003]    At least partially housing a milling roller on a ground milling machine through a so-called rotor box is known from the prior art. Reference is made in this regard to EP 1 070 788 A2, for example. 
         [0004]    Such a rotor box has an ejection opening, through which the soil material (milled material) milled by the milling roller can be ejected from the interior onto a conveyor belt to transport the milled material away, for example. This ejection opening typically does not extend over the entire axial length of the milling roller, so that the milled material must be conveyed in the interior or in the inner chamber of the rotor box out of the side areas to the ejection opening, for example. This is performed in the prior art by arranging the milling cutters in screw-shaped or spiraling (coiled) rows on the milling roller, as known from DE 698 24 340 T2, for example. However, it is disadvantageous in this case that strong wear occurs on the milling roller and in particular on the milling cutters and the milling cutter holders, as well as on the rotor box itself, due to this conveyance of the milled material in the interior of the rotor box, in particular if a large amount of material is present in the rotor box. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention is therefore based on the object of improving the transport of milled material in the interior of the rotor box to the ejection opening and thus reducing the wear in particular. 
         [0006]    The rotor box according to one embodiment of the present invention for a ground milling machine comprises at least one milling roller, which is at least partially accommodated therein, for loosening and/or removing soil material and an ejection opening that allows for the transport of the milling material out of the interior of the rotor box. It is provided that at least one guide device is arranged in the interior of the rotor box, which, in cooperation with the rotating milling roller, causes conveyance of the loosened milled material in the axial direction of the milling roller towards the ejection opening or at least supports such a conveyance. A purpose of the present invention is to achieve an improved milling material transport with at least one guide device in addition to the rotary movement of the milling drum. 
         [0007]    Milled material is understood in the scope of the present invention as the soil material which is pulverized and removed by the engagement of the milling cutters in the soil material. The at least one guide device is used as a passive device for conveying or transporting the loosened milled material with the predominant goal of conveying the milled material in an axial direction of the milling roller to the ejection opening of the rotor box, the energy required for the conveyance being provided by the rotating milling roller. The guide device is advantageously stationary relative to the rotor box and fixedly connected to the rotor box. 
         [0008]    The rotor box according to one embodiment of the present invention has many advantages. For example, one advantage is that less wear occurs on the milling roller and on the rotor box or its walls. A further advantage is that fundamentally, more milled material can be moved in the rotor box according to one embodiment of the present invention due to the improved milling material transport, whereby the milling performance of the ground milling machine is increased. A further advantage is that because of the improved conveyance of the milled material relative to the milling roller, less motor power is required for driving the milling roller (reduction of the drive torque). 
         [0009]    The guide device is preferably formed by a plurality of guide plates, which protrude from the inner wall of the rotor box in the direction of the milling roller. Multiple guide devices can also be provided within the scope of the present invention, which are each formed from a plurality of guide plates. A guide plate is a planar structural element, which is implemented as flat in particular and whose thickness is low in relation to the area extension. A guide plate is preferably, but not necessarily, formed from a sheet-metal material, as are the housing parts of the rotor box. 
         [0010]    It can preferably be provided that the guide plates are arranged diagonally in relation to the axial direction of the milling roller. This is to be understood to mean that the plane of a guide plate intersects the longitudinal axis or the rotational axis of the milling roller at an acute angle, as described in greater detail hereafter in connection with the figures. Ideally, the diagonal arrangement is oriented towards the ejection opening (with respect to the rotational movement of the milling drum). 
         [0011]    It has proven to be advantageous if the guide plates, i.e., at least some and preferably all of the guide plates belonging to the plurality, are arranged surface-parallel and having equal spacing to one another. 
         [0012]    According to another embodiment of the present invention, it is provided that the guide plates, i.e., at least some and preferably all of the guide plates belonging to the plurality, are implemented having the same or identical contour in a side view. 
         [0013]    It can preferably be provided that the guide plates, i.e., at least some and preferably all of the guide plates belonging to the plurality, are at least coarsely adapted to the contour of the milling rotor or to the shape of the cutting circle in the side view toward the milling rotor (view in axial direction). For this purpose, for example, the guide plates can have at least one curved contour section, in particular in the form of a circular arc, facing toward the milling roller. This curved or concave contour section is used as a recess for the milling roller, so that the guide plates can be implemented having a comparatively large area in spite of the cramped space conditions in the interior of the rotor box. It can also preferably be provided that the guide plates have at least one linear contour section facing toward the milling roller in the side view. In one embodiment, it is ideal if at least two linear contour sections are provided in the guide plate, the two linear contour sections also being adapted to the milling roller or the cutting circle of the milling roller in their angle to one another. Of course, it is also possible to provide more than two linear contour sections in the above-described way on the guide plate. 
         [0014]    According to another embodiment of the present invention, it is provided that the guide plates, i.e., at least some and preferably all of the guide plates belonging to the plurality, are arranged in two groups, the guide plates in the first group having an opposite orientation to the guide plates in the second group. Orientation is understood as the direction (positive angle or negative angle) of the surface orientation with respect to the axial direction or with respect to the rotational axis of the milling roller. Through the proposed measure, conveyance of the milled material in opposing axial directions can be obtained, as described in greater detail hereafter in connection with the figures. The two groups are preferably both oriented in the direction of the ejection opening. Accordingly, the two groups of guide plates move the milling material towards each other inside the rotor box with regard to the axial direction. 
         [0015]    It can preferably be provided that the guide plates, i.e., at least some and preferably all of the guide plates belonging to the plurality, are arranged on the inner wall of the rotor box opposite to the ejection opening in relation to the milling roller. This is approximately the area between the rotor box cover and the rotor box rear wall. 
         [0016]    According to another embodiment of the present invention, it is provided that the milling roller accommodated in the rotor box has at least one conveyor device in addition to the milling cutters, which also causes a conveyance of the detached milled material in the axial direction of the milling roller or at least supports such a conveyance when the milling rotor is rotating. The at least one conveyer device is preferably a conveyer scoop having a conveyer surface. Additionally or alternatively, the at least one conveyor device is preferably also arranged on the outer shell of the milling roller main body, like the milling cutters. 
         [0017]    This refinement is based on the concept of a task division between the milling cutters, which are to cause the loosening and/or the removal of the soil material, and the at least one conveyor device, which is to cause or at least support the conveyance of the milled material, preferably in an axial direction of the milling roller. Support is to be understood in particular to mean that the conveyance of the milled material in the axial direction of the rotating milling roller occurs in cooperation with the milling cutters and/or the milling cutter holders. In combination with the guide device or the guide plates arranged in the interior of the rotor box, as a result, outstanding conveyance of the milled material in the interior of the rotor box can be achieved. 
         [0018]    Furthermore, the following advantages result through this refinement. On the one hand, the milling cutters and the milling cutter holders are relieved, which results in significantly reduced wear. Furthermore, the conveyance of the loosened milled material relative to the milling roller is improved, whereby the milling performance can be increased further. The improved conveyance of the milled material relative to the milling roller also has the result, however, that the motor power required for driving the milling roller can be reduced still further (reduction of the drive torque). This is not an exhaustive list. 
         [0019]    It is preferably provided that such a conveyor device is a conveyor scoop having at least one conveyor surface, which is arranged on the outer shell of the roller main body. Such a conveyor scoop primarily has a conveying function or transport function for the milled material. This is not opposed by the fact that the conveyor scoop can also have a milling function, for example, through a milling cutter additionally fastened thereon, which is secondary in relation to the conveyance function, however. Ideally, the conveying function pertains to the transport of the milling material in the rotary direction of the milling drum and, at the same time, in the axial direction of the milling drum towards the ejection opening. 
         [0020]    The conveyor scoop is preferably arranged protruding outward on the outer shell of the roller main body, in particular in a radial direction. A conveyor scoop is preferably fixedly connected to the milling drum main body, preferably welded or screwed onto the milling drum main body. It is particularly preferably provided that the conveyor scoop is replaceably arranged on the roller main body. This replaceability can be produced similarly to the replaceable milling cutters by a conveyor scoop quick-change tool holder. Furthermore, a conveyor scoop can be implemented in one piece or multiple parts. A conveyor scoop (or at least its scoop blade) is particularly a forged product made of a wear resistant metal alloy. 
         [0021]    According to another embodiment of the present invention, a plurality of conveyor scoops is provided, which are arranged distributed in the peripheral direction and/or in the axial direction on the outer shell of the roller main body. Through a plurality of conveyor scoops, the conveyance of the milled material can be significantly improved and/or adapted to special requirements in individual areas or longitudinal sections of the milling roller. Thus, for example, the conveyance can be set to be stronger in the middle section of the milling roller and/or close to the ejection opening than on the axial outer sections. 
         [0022]    The concrete arrangement of the conveyor scoops can also be varied in various ways. Outstanding operating results are obtained, however, if the conveyor surfaces of the conveyor scoops have a different and in particular an opposite orientation in one defined longitudinal section of the milling roller than the conveyor surfaces of the remaining conveyor scoops. An orientation of the conveyor surface is understood in particular as its direction (or the direction of a compensation surface in the case of a curved or concave surface). In this way, a different axial conveyance direction for the milled material can be caused in the associated longitudinal sections, as described in greater detail hereafter in connection with the figures. 
         [0023]    In addition, it is preferably provided that the conveyor scoops having identical or different orientation of the conveyor surface are arranged between adjacent milling cutter rows. This is described in greater detail hereafter in connection with the figures. 
         [0024]    Furthermore, it can preferably be provided that at least one conveyor scoop has a conveyor surface which is oriented parallel to the axial direction of the milling roller. Alternatively and/or additionally, it is provided that at least one conveyor scoop has a conveyor surface which is oriented diagonally (i.e., in particular at an acute angle) to the axial direction of the milling roller. 
         [0025]    According to another embodiment of the present invention, it is provided that at least one conveyor scoop is also implemented as a thrower. A thrower has the function of throwing off the milled material in the radial direction from the milling roller, in order to eject it through the ejection opening in the rotor box, for example. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]    The present invention is described in greater detail hereafter on the basis of the figures. In the schematic figures: 
           [0027]      FIG. 1  shows a top view of a rotor box according to the present invention looking partially into the interior; 
           [0028]      FIG. 2  shows a sectional view through the rotor box of  FIG. 1 , according to the section line B-B indicated in  FIG. 1 ; 
           [0029]      FIG. 3  shows an alternative embodiment of a rotor box in a sectional view, according to the section line B-B indicated in  FIG. 1 ; 
           [0030]      FIG. 4  shows various possible embodiments for the guide plates arranged in the rotor box of  FIG. 2  or  FIG. 3 ; 
           [0031]      FIG. 5  shows a top view of a milling roller, which is preferably used in the rotor box of  FIG. 1 ; 
           [0032]      FIG. 6  shows a top view of another milling roller, which is preferably used in the rotor box of  FIG. 1 ; 
           [0033]      FIG. 7  shows a top view of a further milling roller, which is particularly preferably used in the rotor box of  FIG. 1 ; and 
           [0034]      FIG. 8  shows a perspective view of a conveyor scoop, which is arranged on a milling roller according to  FIGS. 3 to 4 . 
       
    
    
     DETAILED DESCRIPTION 
       [0035]      FIG. 1  shows a top view of a rotor box  100 . The rotor box cover  110  is shown partially cut away, in order to expose the view into the interior. A milling roller  10  is arranged in the interior of the rotor box  100 . The milling roller  10  has a roller main body  12 , on whose outer shell a plurality of milling cutters (not shown in detail) is arranged. The rotational axis of the milling roller  10  is indicated by L, via which the axial direction of the milling roller is also indicated. The external diameter of the milling roller  10  formed by the milling cutter tips is indicated by  11 , which forms a milling circle  11 ′ in milling operation, as indicated in  FIG. 2 . The rotor box  100  has a wall formed from a sheet metal material, which comprises a rotor box cover  110 , a rotor box rear wall (back wall)  120 , and an ejector  130  having an ejection opening  131 . The ejection opening is at least partially arranged within a rotor box front wall  121 . The side wall is identified by  140 . 
         [0036]      FIG. 2  shows a section through the rotor box  100  according to section line B-B indicated in  FIG. 1 , the section plane E extending in the area of the ejection opening  131 . The milling circle (cutter engagement circle) of the milling cutters fastened on the outer shell of the roller main body  12  is identified by  11 ′. In milling operation, the milling roller  10  rotates in the indicated direction R, the milling cutters loosening the soil material (not shown) to be removed and transporting it as milled material. A fraction of the transported milled material is ejected through the ejection opening  131 , which is indicated by the arrow A. So-called throwers can be arranged on the milling roller  10  as a support for this purpose. 
         [0037]    However, the soil material (milled material) removed by the milling roller  10  in the side sections has to be conveyed inside the rotor box  100  to the ejector  130  and the ejection opening  131 , respectively. This is caused in a known way by a spiral arrangement of the milling cutters on the outer shell of the roller main body  12 , as described in greater detail hereafter, which results in strong wear in particular on the milling cutters and the milling cutter holders, however. According to one aspect of the present invention, it is therefore provided that a plurality of planar guide plates  150   a  and  150   b,  which protrude from the inner wall of the rotor box  100  in the direction of the milling roller  10 , is arranged on the rotor box  100  in the interior of the rotor box  100 , whereby in cooperation with the rotating milling roller  10 , a conveyance of the loosened milled material in the axial direction L of the milling roller  10  towards the ejection opening  131  is caused or at least supported. In this way, the wear on the milling cutters and the milling cutter holders can be significantly reduced. Furthermore, the milling performance can be increased, as already described above. Depending on the embodiment, the guide plates  150   a  and  150   b  can also be spatially shaped, i.e., not planar. The guide plates  150   a  and  150   b  can additionally be laterally braced. 
         [0038]    The guide plates  150   a  and  150   b  are arranged on the inner wall opposite to the ejection opening  131  and are preferably fastened, in particular fixedly welded, on both the rotor box rear wall  120  and also on the rotor box cover  110 , as is shown in  FIG. 2 . The rigidity of the rotor box design is also increased in this way. The guide plates  150   a  and  150   b  have a vertical orientation, for example. Alternatively, the guide plates  150   a  and  150   b  can also be arranged inclined in the interior. 
         [0039]    The guide plates  150   a  and  150   b  are arranged diagonally in relation to the longitudinal axis L of the milling roller  10  (which corresponds to the rotational axis). The angle between the plane of a guide plate  150   b  and the longitudinal axis L is indicated by a. The guide plates  150   a  are arranged at the same angle, but having opposite orientation. Furthermore, as can be inferred from  FIG. 2 , the guide plates  150   a  (this is also true for the guide plates  150   b ) have a concave contour section  151  facing toward the milling roller  10 , which is adapted to the outer contour ( 11 ′) of the milling roller  10  formed by the milling cutter tips. A scraping effect for milled material adhering to the milling roller  10  can be caused by the implementation and arrangement of the guide plates  150   a  or  150   b  shown. 
         [0040]    In one particularly preferred embodiment, the guide plates are arranged in two groups, as shown in  FIG. 1 , the guide plates  150   a  in the first group having an opposite orientation to the guide plates  150   b  in the second group. In this way, a conveyance of the milled material in opposite axial directions, concretely towards each other, can be caused, which is indicated by the arrows IIa and IIb. In particular, the milled material can be conveyed in a targeted manner from both side sections of the milling roller  10  in the direction of the plane E (plane of the ejection opening) towards the ejection opening  131  that is located axially spaced with regard to the side walls  140 . Within a group, the guide plates  150   a  or  150   b  are arranged surface-parallel and having equal spacing to one another. 
         [0041]      FIG. 3  shows an alternative possible embodiment for a rotor box  100 , in which the rotor box cover  110  and the transition to the rotor box rear wall  120  are formed by flat plates. The arrangement of the guide plates  150   a  and  150   b  is essentially unchanged. 
         [0042]      FIG. 4  shows, in multiple partial figures a to f, various possible embodiments for the guide plates  150   a  and  150   b  in a side view corresponding to  FIG. 2  or  FIG. 3 . A differentiating feature of the various guide plates is the contour facing toward the milling roller  10  (or the milling circle  11 ′). The possible embodiments shown in  FIG. 4  are in no way exhaustive but rather are to illustrate the different design possibilities. In addition to tapered embodiments oriented toward the milling roller  10  (or the milling circle  11 ′), as shown in  FIGS. 4   c  and  4   d , for example, it is also possible to adapt the contour of the guide plates  150   a/b  facing toward the milling circle  11 ′ to the rounded shape of the cutting or milling circle  11 ′. The coarsest shape of the adaptation is achieved by a linear implementation, which extends diagonally toward the circumference of the milling circle  11 ′, of the contour of the guide plates  150   a/b  facing toward the milling circle, as indicated in  FIG. 4   b , for example. The extent of the adaptation can be improved by contours, which have at least two linear contour sections. Such embodiments are shown in  FIGS. 4   e  and  4   f , for example. Alternatively, the contour of the guide plates  150   a/b  facing toward the milling circle  11 ′ can also be implemented as rounded, for example, so as to be adapted to the rounding of the milling circle  11 ′, as illustrated in greater detail in  FIG. 4   a.    
         [0043]    Milling rollers  10  are described hereafter in connection with  FIGS. 5 to 7 , which are preferably used in a rotor box  100  according to the present invention and which advantageously extend the concept of the present invention. 
         [0044]      FIG. 5  shows a first exemplary embodiment of such a milling roller  10  in a schematic top view. The rotational axis of the milling roller  10  (milling drum) is indicated by L, via which the axial direction of the cylindrical milling roller  10  is also indicated. The rotational direction is indicated by R. A plurality of milling rollers is fastened in a spiral arrangement on the outer shell of the roller main body  12  of the milling roller  10  in a known way. The spiral arrangement line is indicated by  13 . The milling cutters are not shown in detail. The external diameter of the milling roller  10 , which is formed by the milling cutter tips, is indicated by  11 , which forms the milling circle  11 ′ (see  FIG. 2 ) in milling operation. 
         [0045]    Furthermore, multiple conveyor scoops  20 , which are shown in simplified form as rectangles, are arranged on the outer shell of the roller main body  12  of the milling roller  10  between the adjacent milling cutter rows, which result through the spiral arrangement of the milling cutters. The conveyor scoops  20  protrude outward and in particular radially outward from the roller main body  12 , but typically do not protrude beyond the milling cutter tips (contour  11 ). 
         [0046]    Each conveyor scoop  20  has one conveyor surface  21 . By means of the conveyor surface  21 , in milling operation, the milled material detached by the milling cutters from the soil material to be processed is initially moved in the peripheral direction, according to arrow I. A conveyance of the milled material in the axial direction L results, according to the arrow II, from the superposition of this movement in the peripheral direction with the rotational movement of the milling cutters arranged in a spiral (because of the milling roller rotation). An advantage resulting from the conveyor scoops  20  in relation to the solutions known from the prior art is lower wear on the milling cutters and the milling cutter holders. 
         [0047]      FIG. 6  shows a second exemplary embodiment of such a milling roller. In contrast to the first exemplary embodiment of  FIG. 1 , the conveyor scoops  20  or their conveyor surfaces  21  are oriented diagonally to the axial direction L of the milling roller  10 . In this way, the conveyance of the milled material in the axial direction L, especially towards the ejection opening  131 , can be improved. 
         [0048]      FIG. 7  shows a third exemplary embodiment of such a milling roller. In contrast to the first exemplary embodiment of  FIG. 1  and the second exemplary embodiment of  FIG. 2 , the milling cutters are arranged in two opposing spirals, which intersect in axial direction in the plane E that runs through the ejection opening  131 . This is preferably the plane of the ejection opening  131  of the rotor box  100 , as described above. The conveyor scoops  20   a  (according to the illustration in the upper section) have a different orientation (direction) than the conveyor scoops  20   b  (according to the illustration in the lower section). As a result, in the sections separated by the plane E, an opposing conveyance of the milled material is caused, which is indicated by the arrows IIa and IIb. In this way, for example, the milled material can be conveyed from both side sections in a targeted manner in the direction of the plane E (plane of the ejection opening). In particular, additional throwers can be arranged in the plane Eon the main body  12  of the milling roller  10 , which eject the milled material through the ejection opening  131  in the rotor box  100 . 
         [0049]      FIG. 8  schematically shows an exemplary embodiment of a conveyor scoop  20  in a perspective view looking toward the conveyor surface  21 . It is preferably provided that the conveyor surface  21  is implemented on a separate and in particular replaceable scoop blade  22 , as shown. A quick-change tool holder is identified by  23 . 
         [0050]    The features described above can also be combined with one another in embodiments other than the embodiments shown in the figures and described accordingly, if no technical contradiction results therefrom. 
         [0051]    While the present invention has been illustrated by description of various embodiments and while those embodiments have been described in considerable detail, it is not the intention of Applicants to restrict or in any way limit the scope of the appended claims to such details. Additional advantages and modifications will readily appear to those skilled in the art. The present invention in its broader aspects is therefore not limited to the specific details and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of Applicants&#39; invention.