The invention relates in general to the field of energy guide chains for guiding lines, such as for example cables, hoses or the like. The invention relates in particular to energy guide chains with chain links in which at least the side plates or side parts thereof are made of plastics material.
Known energy guide chains have a number of chain links connected together in articulated manner which comprise mutually parallel side parts connected in the longitudinal direction to form two strings connected together by crosspieces, there being no need for all the chain links to be provided with crosspieces. Energy guide chains are typically displaceable in such a manner that they form a first run, a second run and a deflection region of a predetermined radius connecting the two runs. The invention is applicable both to energy guide chains with a self-supporting upper run and to energy guide chains with an upper run which slides or rolls on the lower run.
In conventional energy guide chains, the side parts adjacent to one another in the longitudinal direction are connected in pairs in each string by an articulated joint and are swivelable relative to one another about a common swivel axis which forms the joint axis for swiveling the chain links.
In energy guide chains of the above-stated type, the articulated joints each have, for the purposes of the present invention, a joint journal on a first one of the adjacent side parts and a joint receptacle on the other, second one of the adjacent side parts, the articulated joint typically being formed in the manner of a revolute joint by a journal rotatably mounted in the receptacle.
The invention specifically relates to a structure of energy guide chains in which plain bearing rings or plain bearing bushes are used in the articulated joint between the chain links in order to improve plain bearing pairing and/or to reduce wear.
Such an energy guide chain of the above-stated type is disclosed, for example, in EP 0 861 387 A1 or U.S. Pat. No. 6,065,278A. An energy guide chain for guiding lines, where at least some articulated joints in each case have a separate journal body which is mounted on a first side part to form the joint journal, and a plain bearing ring which is mounted in the joint receptacle on the other, second side part. The separate journal body has a fastening region to be fastened by press-fit connection to the first side part and a circumferential bearing surface that is introducible into the plain bearing ring coaxially to the swivel axis.
In the configuration according to EP 0 861 387 A1, the plain bearing ring can take the form of a flanged bush and be inserted from the inside of the chain link into the side part or side plate. In this exemplary embodiment, the journal body has a disk-shaped step in a central region that is arranged as a spacer between the side parts. According to EP 0 861 387 A1, the additional plain bearing ring and additional journal body are intended be inserted into the side parts or side plates prior to assembly of the chain links. While this solution does indeed enable improved sliding and/or wear properties compared to previously known energy guide chains with side plates of plastics material, it has not yet been able to gain acceptance. One drawback would in particular appear to be that it is always necessary to undo the connection between the chain links in order to replace the wear parts, i.e., the plain bearing ring or the journal body. This makes repairing an energy guide chain that is installed or in service very troublesome or virtually unfeasible.
Another energy guide chain with plain bearing rings is described, for example, in WO 2016/047489 A1. In this configuration too, subsequent replacement of the plain bearing parts as wear parts is only possible once the chain links have been undone in the longitudinal direction since the links are inserted on the mutually facing sides of the side parts, i.e., they are inaccessible from the outside.
However, it is not only during original manufacture that it should be possible to fit the wear parts of the articulated joint easily or with little effort. In view of ever more stringent sustainability requirements, it would be desirable for subsequent, in particular straightforward, replacement of wear parts to be possible. This would make it possible to replace only these wear parts of the articulated joint in order to re-equip the energy guide chain with new articulated joints, i.e., to be able in this way to avoid having to replace the entire energy guide chain.
A further energy guide chain of the above-stated type is known, for example, from WO 2007/121715.
It is therefore a first object of the invention to improve the configuration of an articulated joint with a plain bearing ring in an energy guide chain of the above-stated type, in such a way that subsequent replacement of wear parts of the articulated joint is also simplified, it being intended for assembly or initial manufacture also to remain as simple as possible and in particular for a robust articulated joint also to be achieved.
This is enabled by an energy guide chain or a configuration with chain links.
The object can be achieved in its simplest form in that the separate or additional journal body is configured such that it comprises at least one retaining projection protruding radially relative to the bearing surface at an axially outer end. Using this retaining projection, at least the plain bearing ring can be introduced axially into the joint receptacle of the second side part and/or be secured axially in the joint receptacle or retained therein against axial detachment.
In particular, the retaining projection can axially adjoin the bearing surface on a side of the bearing surface axially remote from the fastening region, in particular on the outside relative to the chain link.
This configuration on the one hand enables a simplified construction of the plain bearing ring or rings of the articulated joint which can take the form of, for example, flangeless, axially short plain bearing bushes, since each plain bearing ring remains retained on the side part by the retaining projection of the journal body. On the other hand, it makes it possible for the journal body to be subsequently readily axially detached, in particular from the outside of the chain link, such that the journal body and plain bearing ring(s) are readily axially detachable from the outside. Conversely, this also enables straightforward axial assembly, the plain bearing ring in particular also being easily assemblable together with the journal body. A preferred configuration is one in which assembly and disassembly can be carried out from the outside of the chain link, i.e., not from the receiving space for the lines.
In one advantageous embodiment, the journal body is configured such that it can also be used to counteract unwanted detachment of the chain links, in particular by the side parts spreading apart transversely of the longitudinal direction. This can be achieved in a simple manner by the at least one retaining projection protruding radially beyond the external diameter of the plain bearing ring and/or the joint receptacle and thus engaging over the second side part so as to retain the latter axially in the direction transverse to the longitudinal direction on the first side part to which the journal body is fastened. The retaining projection can thus perform two functions, namely securing the at least one bearing ring axially or in the lateral direction on the chain link and at the same time also securing the one side part to the other in the lateral direction. This accordingly enables a more robust articulated joint between the chain links that can withstand high forces. The term axial here in particular relates to the axial direction of the swivel axis, while the term radial in particular denotes a direction perpendicular to the swivel axis.
One or more circumferentially distributed retaining projections may be provided on the journal body. A preferred configuration, however, is one in which the retaining projection is embodied in the manner or form of an annular washer-type retaining flange. The latter may preferably be configured to completely surround the swivel axis. The external diameter of the retaining flange is preferably greater than the external diameter of the plain bearing ring and/or greater than the diameter of the joint receptacle.
The fastening region is in particular intended to be fastened to the first side part, which is to have the joint journal, or to a further separate journal body that is mounted on or in the first side part.
In order to transmit forces in the longitudinal direction of the energy guide chain, in particular tensile and shear forces through the plate strings or strings of side parts, it is advantageous for the journal body to have a coaxial fastening cylinder in the fastening region that is fastened, for force transmission in the longitudinal direction, in a matching receptacle or a corresponding seat of the first side part. The corresponding receptacle may in particular be provided as a receiving ring that protrudes axially from the body or from a major face of the first side part. The fastening cylinder can be retained axially in the receiving ring by any suitable connection method, in particular a press-fit connection, screw connection and/or snap-fit connection. Forces advantageously flow in the longitudinal direction between the joined side parts via the fastening cylinder and the receptacle thereof, but not via the axial connection with which the journal body is mounted or retained on the corresponding side part.
The journal body advantageously forms at least part, in particular a force-transmitting component, of the joint journal on the first side part, and can in particular form a detachable joint journal. The journal body is in this case preferably mounted non-rotatably on the first side part, but this is not mandatory.
In order to ensure a particularly robust connection, one embodiment, which is also advantageous in terms of assembly and disassembly, provides that the journal body with the fastening cylinder thereof is retained in the receiving ring with the assistance of a fastening screw. Precisely one or just one fastening screw may be or have been screwed for this purpose to the first side part coaxially to the swivel axis.
The fastening screw of the joint journal is preferably a plastics self-tapping screw. The plastics self-tapping screw may preferably be or have been screwed into a coaxial opening that is provided in the body of first side part as a through-hole or indeed as a blind hole for the plastic self-tapping screw.
In order to avoid undesired force transmission in the longitudinal direction of the energy guide chain onto the fastening screw, the journal body preferably has a coaxial core hole through which the fastening screw is guided with radial clearance such that no alternating loads are transmitted via the fastening screw during back and forth movement.
In order to achieve defined sliding surfaces that rotate toward one another when the chain links are bent, it is advantageous for the detachable journal body to be fastened non-rotatably to the respective side part. This can be easily achieved while maintaining simple assembly and disassembly, in particular in conjunction with a screw connection, if the journal body has profiling in the fastening region for form-locked and non-rotatable connection with corresponding profiling on the (first) side part. One simple configuration that is economical with regard to materials provides that the profiling in particular in each case comprises a first coaxial form-locking crown on the journal body and surrounding the fastening cylinder and a cooperating second coaxial form-locking crown on the receiving ring, in particular on the end face of the receiving ring. A crown serving to provide form-locking may in particular in each case be provided with claws on the end face, end-face toothing or the like or with projections and recesses alternating in the circumferential direction about the swivel axis that engage with one another for non-rotatable connection.
In particular if it forms a sliding surface for the plain bearing ring on its bearing surface, the journal body can be manufactured from a specific plastics material that differs from the plastics material of the side parts. In particular, the journal body can be made of a higher grade plastics material or a plastics material selected with regard to favorable plain bearing pairing and/or improved sliding and/or wear properties.
A compact structure that is economical with regard to materials is fundamentally desirable for the replaceable journal body. In one advantageous embodiment, the journal body is embodied in the manner of a stopper having an axial structural length which is significantly shorter than the diameter, in particular than the diameter of the bearing surface. The journal body is thus relatively short, for example shorter than conventional joint pins that extend through two side parts. The structural length of the journal body is preferably only insignificantly greater than the wall thickness of a side part in the region around the articulated joint, for example less than 1.2 times the wall thickness.
Particularly compact structure of the journal body can be provided by the fastening region being arranged axially, preferably at least partially or completely, within a cylinder formed by the bearing surface, the fastening cylinder particularly preferably being formed by an annularly circumferential recess and/or not protruding axially beyond the bearing surface. The fastening region may in particular be embodied at least in part or predominantly at the face at the axial end of the journal body remote from the retaining projection.
The journal body may be dimensioned such that the axial distance between the retaining projection protruding relative to the bearing surface and the one axially outer end and the other axially outer end is only insignificantly greater than the wall thickness of the second side part to be bearing mounted, such that axial movement clearance remains for relative swivel movement.
Two basic structures can fundamentally be considered for providing favorable plain bearing pairing using at least one additional plain bearing ring.
In order to form sliding surfaces that can rotate on one another, the journal body may itself form a sliding surface on the bearing surface thereof. The bearing surface of the journal body can for this purpose have an outer sliding surface with which the inner surface of the plain bearing ring interacts rotatably.
Alternatively, the plain bearing pairing may also be embodied by two interacting sliding rings that form or include the sliding surfaces of the articulated joint that are rotatable on one another. A first plain bearing ring can for this purpose be fastened non-rotatably in the joint receptacle of the second side part and a further second plain bearing ring can be arranged, rotatably or non-rotatably, on the bearing surface of the journal body. The second plain bearing ring then forms an outer surface with which an inner surface of the first plain bearing ring interacts rotatably in order to provide the sliding surfaces that are rotatable on one another. One advantage of this configuration is that the journal body need not be manufactured from a tribologically optimized plastics material and is optionally also subject to no or only relatively low wear. Among other things, the cost of higher grade tribological plastics materials can accordingly be minimized.
The further, second plain bearing ring between the journal body and the first plain bearing ring can be loosely rotatably or floatingly retained on the journal body such that frictional wear thereof can be automatically distributed around the circumference. The first plain bearing ring can then be selected from a tribologically optimized and more wear-resistant material such that optionally only the second plain bearing ring, which is intended to be subjected to greater wear, need be replaced as a wear part in order to reinstate the articulated joint. This can, however, likewise be provided if the second plain bearing ring is mounted non-rotatably on the journal body, in particular non-rotatably by press-fit connection to the bearing surface thereof. This also enables simple subsequent replacement of the second plain bearing ring.
The first or only plain bearing ring preferably has means for form-locked, non-rotatable connection to the corresponding side part. A non-rotatable connection can additionally or alternatively also be achieved by press-fit connection in the joint receptacle on the second side part. It is advantageous for there to be no rotation between the plain bearing ring and its receptacle or the joint receptacle on the side part, in order to avoid wear to this receptacle or the joint receptacle and thus to the side part or chain link itself.
It is advantageous structurally and with regard to handling for the journal body to be manufactured as a cylindrical, in particular rotationally symmetrical, component.
The journal body is preferably manufactured as a molded part of plastics material, in particular as an injection molding, it being possible to select for this purpose, in line with requirements that differ from the requirements for the side plates themselves, a possibly more suitable plastics material that differs from the plastics material of the side parts.
The side parts and/or chain links per se can also be manufactured from plastics material, in particular as injection moldings. To reduce costs, the side parts can be manufactured from a less costly plastics material that differs from the plain bearing ring and/or the journal body. The chain links are preferably manufactured from a fiber-reinforced thermoplastics material, for example a glass fiber reinforced polyamide.
The or each plain bearing ring, on the other hand, is preferably manufactured from a tribologically optimized tribopolymer, preferably a tribopolymer with one or more solid lubricants in a suitable matrix polymer.
If the journal body provides a sliding surface, it is advantageous for at least the bearing surface of the journal body to be manufactured from a tribopolymer with one or more solid lubricants.
To further simplify assembly and maintenance, the journal body can have one or more snap-fit connectors for axial retention of a plain bearing ring such that, on assembly/disassembly, the plain bearing ring can be mounted on or detached from the chain link in just one step together with the journal body.
In an energy guide chain according to the invention, all the chain links can have the proposed articulated joint configuration with at least one plain bearing ring and a journal body, or at least a predominant proportion, or indeed just the chain links in a longitudinal portion that is particularly susceptible to wear.
The invention thus also relates to just a short portion of an energy guide chain with at least two chain links. Each articulated joint can here be configured according to one of the preceding embodiments.
The features described above and claimed hereinafter are each to be considered to be individually essential to the invention. In particular, the subjects of the subclaims may constitute independent inventions which may also be the subject-matter of a divisional application optionally even without the characterizing or other features of the present main claim.
Further details, features and advantages of the invention are revealed without limitation to the above by the following description of some preferred embodiments made with reference to the appended figures, in which:
Each chain link has two link plates or side parts 10A, 10B which are connected together and held parallel to one another by crosspieces 12A, 12B.
In order to connect the chain links 2 in articulated manner, two side parts 10A and 10B adjacent in the longitudinal direction L are each connected by an articulated joint 100 and are swivelable relative to one another about a common swivel axis S. A first exemplary embodiment of the articulated joint 100 will now be explained in greater detail with reference to
In
The articulated joints 100 each have a journal body 20 that is manufactured separately from or is separate from the side parts 10A, 10B and is mounted on the side part 10A, regarded as the first, to form the joint journal.
The articulated joints 100 in
At the axial end facing the inside of the chain, the journal body 20 has a fastening region 20A that has a fastening cylinder 23 (
To fasten the journal body 20 in place, in
The journal body 20 furthermore has a circumferential, cylindrical bearing surface 20B that, in the assembled state, is introduced coaxially to the swivel axis into the plain bearing ring 21 and is surrounded by the latter. The journal body 20 is manufactured from a plastics material as a cylindrical, rotationally symmetrical injection molding.
In the example from
According to the invention, the journal body 20 furthermore has, at its axially outer end remote from the fastening region 20A, one or more retaining projections protruding radially relative to the bearing surface, in
As
In
In
Finally,
Only the significant differences will be briefly explained. In
Finally,
Number | Date | Country | Kind |
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PCT/IB2021/000853 | Dec 2021 | WO | international |
Filing Document | Filing Date | Country | Kind |
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PCT/IB2022/000335 | 6/16/2022 | WO |