Roller assembly, toothed segment stack for a roller assembly, toothed segment for a toothed segment stack, method for assembling and repairing a roller assembly

Abstract

Roller assembly (1) for a wood processing plant with a roller body (2) which is intended to be driven for a rotational movement of the roller assembly (1), and with a plurality of toothed segments (7), each comprising a plurality of toothed elements (8) which are intended to come into contact with a tree trunk during a rotational movement of the roller assembly (1), wherein at least two tooth segments (7) are detachably connected to one another and at least partially form a tooth segment stack (6), and the tooth segment stack (6) is detachably arranged on an outer peripheral side of the roller body (2)

Description

The invention relates to a roller assembly, a toothed segment stack for a roller assembly, a toothed segment for a toothed segment stack and methods for assembling and repairing a roller assembly.In industrial wood processing, driven rollers are frequently used to set a tree trunk to be processed in a feed movement, for example so that it can be conveyed to various processing stations and processed into board goods or comparable products. For this purpose, the rollers are each set in a rotational movement and come into contact with the tree trunk on their outer circumferential surfaces. For simplified generation of the feed movement, the outer circumferential surface of such a roller can be occupied by profile elements.Although the rollers described above are advantageous, they can generally be designed as comparatively simple structured and one-piece components, which leads to high reliability in their operation. However, unavoidable wear phenomena occur on the outer circumferential surfaces, which typically require replacement of the entire roller. This is associated on the one hand with a high consumption of resources and on the other hand also with a high outlay on dismantling, in particular since the roller has to be separated from the drive components of the wood processing installation concerned.The object of the invention is thus to propose means by means of which the above-mentioned disadvantages can be overcome.The object is achieved by means of a roller assembly according to claim 1, a stack of toothed segments according to claim 12, a toothed segment according to claim 13, a method for assembling a roller assembly according to claim 14 and a method for repairing a roller assembly according to claim 15.The roller assembly according to the invention is intended for use in a wood processing plant and comprises a roller body which is provided for being driven for a rotational movement of the roller assembly. The roller assembly further includes a plurality of tooth segments each including a plurality of tooth elements. The toothed segments are provided for coming into contact with a tree trunk during the rotational movement of the roller assembly. At least two of the toothed segments are detachably connected to one another and form a toothed segment stack or a part of a toothed segment stack. This stack of toothed segments is arranged detachably on an outer circumferential side of the roller body.It is an advantage of the roller assembly according to the invention that it has toothed segments which are separate from the roller body and which can be exchanged as required as soon as wear phenomena occur. In particular, it is therefore not necessary to replace the entire roller assembly, but only the relevant toothed segments, which leads to a reduced resource requirement. However, the replacement does not take place here by dismantling individual toothed segments, but one or more stacks of toothed segments. This aspect of the invention is based on the finding that individual tooth elements are rarely affected by wear phenomena or damage, so that as a rule a plurality of adjacent tooth elements are as frequently involved. The dismantling and replacement of entire stacks of toothed segments thus result in advantages with respect to the handling of the components of the roller assembly to be replaced, as a result of which the dismantling and assembly effort is low overall.The roller body can be considered within the scope of the invention as a substantially rotationally symmetrical component or assembly, which preferably has a mechanical interface in order to be connected to at least one drive component of a wood processing plant. The roller body is preferably designed as a cylindrical sleeve, in the interior of which the roller body can be mechanically coupled to the drive component. Preferably, the roller body is made of metal, in particular steel. On its outer circumferential side, the roller body can have a surface and / or mechanical interfaces which is smooth and / or profiled at least in regions in order to accommodate the toothed segment stacks, for example by means of a form-fit and / or force-fit connection. It is within the scope of the invention that the roller body and thus the entire assembly is mounted vertically with its axis of rotation in order to generate a translatory movement of the tree trunk or is inclined in comparison thereto in order to generate a rotational movement of the tree trunk about its trunk axis in addition to the translatory movement.A toothed segment can have a curved base body which has an arcuate course in a plane. The plurality of tooth elements may be arranged on a convex outer side. On a concave inner side, the toothed segment can correspond at least in regions to the outer circumferential side of the roller body. On the end faces, the toothed segments can be substantially flat, in order to be able to be brought into flush, full-surface contact with one another. It is also within the scope of the invention that the toothed segments have interlocking elements on their end faces that correspond to one another in order to be able to be centered relative to one another in order to produce a toothed segment stack.The invention is in principle not restricted to which geometry the tooth elements have. In a simple embodiment, the tooth elements are at least partially triangular in cross section and are arranged distributed uniformly on the tooth segment, in particular on its convex outer side. A tip of such a tooth element faces away from the roller assembly in the mounted state on the roller body and preferably serves to engage with the surface of the tree trunk or to penetrate into the latter in order to convert the rotational movement of the roller assembly into a feed movement of the tree trunk. It is also within the scope of the invention that the tooth elements are each rectangular or square at least in regions.A stack of toothed segments is formed in the sense of the invention by at least two toothed segments. The stacks of toothed segments are preferably joined to form the stack of toothed segments by being braced detachably with one another, in particular being braced axially with respect to an axis of rotation of the roller assembly. It is conceivable that the toothed segments are only braced with one another as a result of their mounting on the roller body. In this case, they can be present in a spatially bundled manner beforehand as a stack of toothed segments, which is arranged on the roller body before they are braced to form the stack of toothed segments. However, it is particularly advantageous if the toothed segments are pre-assembled to form the toothed segment stack in a state detached from the roller assembly and are braced with respect to one another. This enables, in the manner already explained above, simple exchangeability of the toothed segment stack on the roller assembly.The toothed segments can be centered with respect to one another by means of a clamping element and can be clamped along a longitudinal extension axis of the clamping element. In particular, the clamping element can be a clamping sleeve or a tension rod, by means of which the toothed segments are centered. It is conceivable that a first toothed segment arranged on the edge side exerts a first clamping force against the remaining toothed segments of the toothed segment stack by means of a screw head of a clamping screw which is in engagement with the clamping element. On an opposite side of the toothed segment stack, a clamping screw or a comparable clamping element can likewise be arranged, which exerts a second clamping force against a second toothed segment arranged on the edge side. Alternatively, the clamping element on the opposite side of the toothed segment stack can also be connected directly to a toothed segment arranged on the edge side, so that the clamping force can be exerted by means of a single clamping screw.Preferably, a plurality of stacks of gear segments are arranged distributed on the outer circumferential side of the roller body. This aspect of the invention is based on the finding that a distributed arrangement of stacks of toothed segments on the outer circumferential side of the roller body promotes the exchangeability of the toothed segments. Studies have shown that a number of at least two, but preferably three, tooth segment stacks which cover the entire outer circumferential side of the roller body is particularly advantageous. This is basically related to the fact that the stacks of toothed segments, which each cover only a part of the outer circumferential side of the roller body, have a significantly lower weight than, for example, a structure in which the toothed elements are formed continuously in order to cover the entire outer circumference of the roller body. In addition, by dividing into a plurality of tooth segment stacks, it is possible to arrange these radially on the roller body, so that the latter does not have to be disassembled for an exchange of tooth segments. It is within the scope of the invention that a total of four, five, six, seven or eight tooth segment stacks can be arranged distributed over the outer periphery of the roller body. Such a low number of stacks of toothed segments results in a particularly low outlay on assembly and repair on the roller assembly and promotes the stability of the stacks of toothed segments, since they can be formed comparatively wide in the circumferential direction.In an advantageous development, the roller body is connected on the outer circumferential side in a form-fitting manner to the toothed segment stack by means of at least one feather key.The feather key can be considered within the scope of the invention as a force-transmitting element which is provided to transmit the rotational movement of the roller body to the toothed segments or toothed segment stacks arranged on the outer circumference, or vice versa. In particular, the feather key is configured to transmit a force and / or movement from the roller body to the toothed segment stack and / or vice versa, preferably only in the tangential direction with respect to the rotational movement of the roller assembly. For this purpose, the key may be disposed in a key groove of the roller body formed on the outer circumferential side of the roller body. The feather key and / or the feather key groove can each be configured to be elongate and in this case preferably have a length which substantially corresponds to the height of the roller body. Preferably, the feather key can be arranged in the feather key groove in a releasable manner, preferably by means of a press fit and / or by means of a screw connection.In an advantageous development, the roller assembly has a flange element which is arranged in an end-face region of the roller body and is connected to the roller body.The flange element can serve as an axial stop element, by means of which a toothed segment stack can be aligned along the longitudinal extension axis of the roller body during its mounting. This simplifies in particular an exchange of a toothed segment stack.Preferably, the flange element comprises a toothed ring. This allows a high degree of functional integration to be achieved, since the flange element, in the manner already explained above, can on the one hand serve as an axial stop element, but on the other hand can also be provided with a plurality of tooth elements which can come into contact with the tree trunk. It is within the scope of the advantageous development that the flange element is braced with the toothed segment stack or serves merely as an axial support.It is within the scope of the advantageous development that the flange element and / or the toothed rim can be detachably connected to the roller body. However, since the end-face region of the roller assembly is affected by damage or wear phenomena slightly during normal operation than a centrally located axial section, it is also conceivable that the flange element and / or the toothed rim can be non-detachably connected to the roller body.Preferably, at least two toothed segments of the toothed segment stack are formed differently, in particular in a number and / or geometry and / or arrangement of their toothed elements.For their transport, the tree trunks are usually moved substantially along the trunk axis and in the process lie on a conveyor chain or a comparable receptacle, while the roller assembly is arranged laterally to the tree trunk. Since tree trunks generally have an at least approximately circular cross section due to their natural growth, the roller assembly does not come into contact with the tree trunk on the outside over its entire height, but rather in an axial partial area. Depending on how much the diameters of the conveyed trunks vary, several different axial partial areas can also result, in which a roller assembly comes into contact with the trunks. Since the masses of the tree trunks differ among other things with varying diameters, it can be advantageous to design the toothed segments of the roller assembly differently in order to be able to ensure reliable transport even with varying trunk dimensions. In particular, the tooth elements of a first tooth segment in a first axial section of the roller assembly can have a pitch and / or tooth size which differ from the tooth elements of a second tooth segment in a second axial section of the roller assembly.In an advantageous development, a holding element is arranged between two adjacent tooth segment stacks, by means of which the two adjacent tooth segment stacks are fastened, in particular clamped, radially on the roller body. This makes it possible to fix the toothed segment stacks to the roller assembly. In combination with a feather key arranged between the roller body and one of the stacks of toothed segments, the holding element can be dimensioned to exert a radially directed holding force on the stacks of toothed segments, while the feather key connection is dimensioned in such a way as to transmit a force directed tangentially with respect to the rotational movement from the roller body to the stack of toothed segments and / or vice versa. This allows a high degree of functional separation to be achieved, as a result of which the feather key and the retaining element can each be of simple dimensions and design. The holding element preferably has at least one tooth element on a side facing away from the roller body. As a result, the entire outer periphery of the roller assembly can be occupied by tooth elements. In particular, the holding element is a clamping element, by means of which two adjacent tooth segment stacks are fastened to the roller body, wherein the clamping element and at least one of the tooth segments can be connected to one another in a positive-locking manner.In an advantageous development, a toothed segment has two edge regions and a core region lying therebetween, wherein the mechanical rigidity in at least one of the edge regions is lower than in the core region.According to the above-described development, the toothed segments of a toothed segment stack can be positioned with their core regions on the outer circumferential side of the roller body and fastened at the edge regions on the roller assembly, for example by means of the above-described holding element. In this case, it is not necessary for all toothed segments to bear flush against the outer circumferential side of the roller body when the toothed segment stack is placed on. Rather, the flush contact can only be established as a result of the fastening by the edge regions of the toothed segments being pressed against the roller body, preferably by means of the retaining element. Overall, the different stiffnesses result in an advantageous stress distribution in the roller assembly and in particular in the toothed segments or the toothed segment stack.The different stiffnesses between the edge regions and the core region of a toothed segment can be set in different ways. It is also advantageous if the toothed segment is provided with a groove in the edge region on a side facing away from the toothed segments. This allows the stiffness to be reduced in a structurally simple manner.In an advantageous development, the toothed segment stack has at least one intermediate segment which is arranged between two toothed segments.Studies by the applicant have shown that it is advantageous if the roller assembly is not continuously occupied with tooth elements over its entire height. Instead, tooth elements which are spaced apart from one another along the axis of rotation of the roller assembly can better penetrate into the surface of the tree trunk in order to set it in a transport movement. In addition, a distance between the tooth elements of two adjacent tooth segments prevents an undesired rotational movement of the tree trunk during its advancing movement.The toothed segments and the intermediate segment are preferably made of different materials. In particular, it has proven to be advantageous to form the toothed segments from metal and the intermediate segment from plastic. This improves the releasability of the toothed segments of a toothed segment stack. This is related, among other things, to the fact that a direct contact between two metallic tooth segments can lead to a mechanical connection between the tooth segments as a result of corrosion. In comparison, an intermediate segment made of plastic and a toothed segment made of metal do not tend, or to a significantly lesser extent, to react with one another.In an advantageous development, the toothed segment is produced by means of laser cutting.Laser cutting offers various advantages in the production of the toothed segments. The precision of the laser beam enables particularly dimensional cuts, since the toothed segments are only slightly thermally influenced. In particular, the toothed segments can be produced with deviations in the range between ±0.1 mm and ±1 mm. In addition, the toothed segments can be produced essentially free of burr, for which reason subsequent post-processing can be dispensed with in particular during their production.As mentioned above, the object of the invention is also achieved by means of a toothed segment stack for the roller assembly according to the invention or an advantageous development thereof and by a toothed segment for such a toothed segment stack. With regard to the conceivable embodiments of the toothed segment stack or of the toothed segment and the advantages achievable therewith, the statements regarding the roller assembly and its advantageous developments apply accordingly.The object is furthermore achieved by a method for assembling a roller assembly. According to the invention, a plurality of tooth segments is provided, each of which comprises a plurality of tooth elements which are provided for coming into contact with a tree trunk during a rotational movement of the mounted roller assembly. At least two toothed segments are braced to form a stack of toothed segments. Furthermore, a roller body is provided, on the outer circumferential side of which the toothed segment stack is arranged in a detachable manner.In particular, the method according to the invention is used to mount the roller assembly according to the invention or an advantageous refinement thereof. At least in this respect, the method enables a particularly simple assembly of a roller assembly and the above explanations apply correspondingly to the roller assembly according to the invention and to its advantageous developments.The object is also achieved by a method for repairing a roller assembly, in which a roller assembly is provided, which comprises a roller body which is provided for being driven for a rotational movement of the roller assembly, and having a plurality of toothed segments which each comprise a plurality of toothed elements which are provided for coming into contact with a tree trunk during a rotational movement of the roller assembly. At least two toothed segments are braced to form a toothed segment stack, and the toothed segment stack is arranged detachably on an outer circumferential side of the roller body. For repair, a stack of gear segments is detached from the roller assembly and replaced with another stack of gear segments.In particular, the method according to the invention serves for repairing a roller assembly according to the invention or an advantageous development thereof. In this respect, the method serves for a particularly simple replacement of stacks of toothed segments which, as a result of the use of the roller assembly, have wear phenomena or damage.Advantages of the invention are explained below with reference to exemplary embodiments and the figures.They show FIG. 1 shows a roller assembly; FIG. 2 shows a roller assembly in exploded view; FIG. 3 shows a toothed segment stack with a plurality of toothed segments.In industrial wood processing, it is frequently necessary to set a tree trunk in a feed movement. For this purpose, one-piece rollers of simple design are usually used, which are set into a rotational movement and come into contact on their outer circumferential side with the tree trunk in order to move the latter.For an improved transmission of force for generating the advancing movement of the log, the roller can be offset on the outer circumferential side with profile elements which, however, can wear as a result of the operation of the roller. Usually, the roller must be completely replaced by an intact roller in such a case, which is usually associated with a high outlay on assembly on the wood processing installation concerned and a high outlay on resources. In order to reduce these disadvantages, the roller assembly 1 shown in FIG. 1 has a structure with which it is possible to exchange damaged components arranged on the outer circumference in an inexpensive manner, if necessary.The roller assembly 1 comprises a roller body 2 which is provided for being set into a rotational movement about the rotational axis 3 by means of a drive. The roller body 2 is designed as a substantially rotationally symmetrical hollow cylinder, on the outer side of which three key grooves 4 are arranged, of which only one key groove 4 is provided with a reference sign. Via corresponding three feather keys 5, the rotational movement is transmitted to a plurality of tooth segment stacks 6 arranged on the outside.Overall, the roller assembly 1 shown in FIG. 1 has three stacks of toothed segments 6, of which only one stack of toothed segments 6 is provided with a reference sign for the sake of better clarity. Each tooth segment stack 6 has a plurality of tooth segments 7, of which likewise only one tooth segment is provided with a reference sign.The toothed segments 7 are each metal components which are produced by means of laser cutting and which serve to transmit the rotational movement of the roller assembly 1 to a tree trunk. For this purpose, the toothed segments 7 each have a plurality of toothed elements 8, which are provided in order to come into contact with a tree trunk surface and partially penetrate into it in order to generate the advancing movement of the tree trunk as a result of the rotation of the roller assembly.A particular advantage associated with the roller assembly according to FIG. 1 is that the toothed segment stacks 6 are arranged distributed on the outer circumference around the roller body 2. In the event that the toothed segments 7 or a toothed element 8 arranged thereon are damaged, the toothed segment stacks 6 can be easily exchanged in that they can be removed from the roller body 2 in the radial direction. Subsequently, an already pre-assembled toothed segment stack 6, instead of the disassembled toothed segment stack 6, can also be attached to the roller body 2 in the radial direction and fixed thereto. It is not absolutely necessary to disassemble the roller body 2. Rather, it can remain mounted on the wood processing installation during the entire assembly or repair method.Instead of replacing the entire toothed segment stack, only the damaged toothed segment 7 on the disassembled toothed segment stack 6 can also be replaced, so that it can be arranged again on the roller body 2.The exchangeability of individual tooth segment stacks 6 is promoted by the fact that the tooth segments 7 of the tooth segment stacks 6 are axially braced with one another. As a result, the toothed segments 7 are also present in the disassembled state as a spatially bundled toothed segment stack 6.As is explained in more detail with reference to FIG. 3, two tension rods 12 (see FIG. 3 ) serve for each stack of teeth 6 to center the toothed segments 6 and to clamp them via the toothed segments 6 located on the edge side.For simple assembly, the roller assembly 1 has a flange element 9 with a revolving toothed rim, which are arranged on an end face of the roller body 2 and are not structurally connected to the toothed segment stacks 6. Rather, the flange element 9 serves as an axial stop element during the assembly of the toothed segment stacks 6 on the roller body 2.The roller assembly 1 has three clamping elements 10, only one of which is provided with a reference sign. One of the clamping elements 10 serves in each case to connect two adjacent toothed segment stacks 6 radially to the roller body 2. This allows a detachable connection to be formed in a simple manner, which facilitates the exchange of individual tooth segment stacks 6.Each of the toothed segments 7 has circumferentially two edge regions with respect to the axis of rotation 3 and a core region located therebetween. In order that during the assembly of the tooth segment stacks 7 by means of the clamping elements 10 no excessive clamping of individual tooth segments 6 occurs, these have in each case a lower stiffness in the edge regions than in the core region. This is realized by means of a groove 11 which allows a deformation of the toothed segments 6 when the toothed segment stacks 7 are fastened to the roller body 2 by means of a clamping element 10. In addition, this makes possible a predominantly flush contact of the toothed segment stacks 6 on the outer circumferential side of the roller assembly 2.FIG. 2 shows the roller assembly 1 according to FIG. 1 in an exploded view. As can be seen in particular in FIG. 2, the flange element 9 with the toothed rim arranged on the outside is not part of the releasable toothed segment stack 6, but is connected to the roller body 2. Otherwise, however, the explanations relating to FIG. 1 apply accordingly.FIG. 3 shows a toothed segment stack 6, which has already been described with reference to FIGS. 1 and 2. As can be seen from FIG. 3, two tension rods 12, of which only one tension rod is shown in section and is provided with a reference sign, extend through the toothed segment stack 6. The assembly of the tension rods 12 and the support element 13 can serve as an assembly aid in the disassembled state of the roller assembly, wherein the toothed segments 7 can be positioned along the tension rods 12 and can be braced via a clamping screw to form the toothed segment stack 6.As is likewise shown on the basis of FIG. 3, the toothed segment stack 6 has not only a plurality of toothed segments 7, but also a plurality of intermediate pieces 14, which are each arranged between two adjacent toothed segments 7. The intermediate pieces 14 serve to generate regular distances between the tooth segments 7 and the tooth elements 8 in the axial direction. This improves the penetration behavior of the tooth elements 8 into the surface of a tree trunk to be transported.

Claims

Roller assembly (1) for a wood processing plant, having a roller body (2) which is provided for being driven for a rotational movement of the roller assembly (1), and having a plurality of toothed segments (7) which each comprise a plurality of toothed elements (8) which are provided for coming into contact with a tree trunk during a rotational movement of the roller assembly (1), wherein at least two toothed segments (7) are detachably connected to one another and at least partially form a toothed segment stack (6) and the toothed segment stack (6) is detachably arranged on an outer circumferential side of the roller body (2).Roller assembly according to claim 1, wherein the at least two toothed segments (7) are braced with one another, in particular axially with respect to an axis of rotation of the roller assembly.Roller assembly (1) according to claim 1 or 2, wherein the roller body (2) is connected on the outer circumferential side in a form-fitting manner to the toothed segment stack (6) by means of a feather key (5).Roller assembly (1) according to one of Claims 1 to 3, having a flange element (9) which is arranged in an end-face region of the roller body (2) and is connected to the roller body (2).Roller assembly (1) according to claim 4, wherein the flange element (9) comprises a toothed rim.Roller assembly (1) according to one of Claims 1 to 5, having a plurality of stacks of toothed segments (6), in particular three stacks of toothed segments (6), which are arranged distributed on the outer circumferential side of the roller body (2).Roller assembly (1) according to one of Claims 1 to 6, in which at least two toothed segments (7) of the toothed segment stack (6) are of different design, in particular wherein the toothed elements (8) of a first toothed segment (7) have a number and / or geometry and / or arrangement in a first axial section of the toothed segment stack (6), which differ from a number and / or geometry and / or arrangement of the toothed elements (8) of a second toothed segment in a second axial section.Roller assembly (1) at least according to claim 6, wherein a holding element (10) is arranged between two adjacent toothed segment stacks (6), by means of which holding element the two adjacent toothed segment stacks (6) are radially fastened, in particular clamped, to the roller body (2).Roller assembly (1) according to one of the preceding claims, in which at least one toothed segment (7) has two edge regions and a core region lying therebetween, and the toothed segment (7) is formed in such a way that the mechanical rigidity in at least one of the edge regions is lower than in the core region.Roller assembly (1) according to claim 9, wherein the toothed segment (7) has a groove (11) in the edge region on a side facing away from the toothed elements (8).Roller assembly (1) according to one of the preceding claims, in which the stack of toothed segments (6) has at least one intermediate segment (14) which is arranged between two toothed segments (7), wherein the intermediate segment (14) is produced in particular from a different material than the toothed segments (7), wherein in particular the intermediate segment (14) is produced from plastic and the toothed segments (7) are each produced from metal.Roller assembly (1) according to one of the preceding claims, in which the toothed segment (7) is produced by means of laser cutting.A stack of toothed segments (6) for a roller assembly (1) according to one of claims 1 to 12.Toothed segment (7) for a toothed segment stack (6) according to claim 13.Method for assembling a roller assembly (1), in particular a roller assembly (1) according to one of Claims 1 to 12, in which a plurality of toothed segments (7) is provided, which each comprise a plurality of toothed elements (8) which are provided for coming into contact with a tree trunk during a rotational movement of the assembled roller assembly (1), and at least two toothed segments (7) are joined together in a releasable manner to form a stack of toothed segments (6), and in which a roller body (2) is provided, on the outer circumferential side of which the stack of toothed segments (6) is arranged in a releasable manner.Method for repairing a roller assembly (1), in particular a roller assembly (1) according to one of Claims 1 to 12, in which the roller assembly (1) is provided, which comprises a roller body (2) which is provided for being driven for a rotational movement of the roller assembly (1), and having a plurality of toothed segments (7) which each comprise a plurality of toothed elements (8) which are provided for coming into contact with a tree trunk during a rotational movement of the roller assembly (1), wherein at least two toothed segments (7) are joined detachably to form a toothed segment stack (6) and the toothed segment stack (6) is arranged detachably on an outer circumferential side of the roller body (1), wherein a toothed segment stack (6) is released from the roller assembly (1) and is exchanged by another toothed segment stack (6).

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