JOINT CHAIN

Description

[0001] The present invention relates to a link chain according to the preamble of claim 1.

[0002] A link chain, particularly a bush chain, is essentially made up of two endlessly arranged elements. These elements are also referred to as inner and outer links. An outer link typically consists of two outer plates, which are firmly connected by two pins. An inner link is usually composed of two inner plates and two bushings, which, together with the pins of the adjacent outer links, form a chain link. These links enable the link chain, for example, to wrap around the sprockets in the drive train.

[0003] A key criterion for the application of a link chain is its transmittable tensile force. In principle, a corresponding transmittable tensile force can be achieved through material selection, heat treatment, and material thickness of the individual link chain components. However, there are limitations to the material selection and dimensioning, for example, due to the available installation space and, ultimately, the reasonable cost of a link chain.

[0004] A link chain according to the preamble of claim 1 is known from JP 2008 164043 A. The link chain described therein has alternating inner and outer plates, as well as chain links connecting them, each formed by a bushing and a pin. A circumferential groove is provided in the opposing areas of the inner and outer plates, with a groove in an inner plate and a groove directly opposite it in an outer plate forming a receiving space for a sealing ring. The sealing ring is loosely fitted into this receiving space.

[0005] A link chain according to the preamble of claim 6 is known from WO 2005 / 043005 A1. The link chain described therein is designed as a bicycle chain. The link chain has alternating inner and outer link plates, as well as chain joints connecting them, each formed by a bushing and a pin. An inwardly projecting thickening is arranged approximately centrally on the inner sides of the outer link plates. This thickening is intended to prevent the link chain, designed as a bicycle chain, from twisting during gear shifting.

[0006] Another articulated chain is known from US Pat. No. 5,322,483 A. The articulated chain described therein is also designed as a bicycle chain. The articulated chain has alternating inner and outer plates, as well as chain links connecting them, each formed by a pin. US Pat. No. 5,322,483 A discloses an outer plate with a hole located approximately centrally, the edges of which are thinned and protrude inward. Lubricant can be introduced into the interior of the chain through the hole.

[0007] Another articulated chain is known from JP 2016 075391 A. The articulated chain described therein is designed as a rotary chain or chain with offset plates.

[0008] CN 2546688Y discloses a link chain with a shallow annular groove into which an annular projection engages to prevent dirt from entering the chain link.

[0009] The present invention has for its object to propose an improved articulated chain of the type mentioned at the outset, in particular to propose an articulated chain which can transmit a higher tensile force and / or an improved dynamic load capacity with otherwise the same or similar dimensions, in particular the same weight.

[0010] According to the invention, this object is achieved by a link chain of the type mentioned at the outset with the characterizing features of claim 1.

[0011] According to claim 1, a labyrinth seal is provided between the outer plate and the inner plate, which labyrinth seal comprises at least one nose and at least one groove, wherein the at least one nose and the at least one groove are designed in a length or depth between 10% to 50% of the average respective plate thickness, preferably in a range of 20% to 40% of the respective average plate thickness, wherein the labyrinth seal is designed such that in the event of an overload of the articulated chain, the flow of force within the articulated chain is partially redirected via the labyrinth surfaces formed by the at least one nose and the at least one groove, wherein the at least one groove is formed in the inner plate and the at least one nose is formed on the outer plate or wherein the at least one groove is formed in the outer plate and the at least one nose is formed on the inner plate.The outer link plate is provided with a section offset from the center of the chain, with the offset section being located in a central area of ​​the outer link plate between the chain joints. This measure ensures that the at least one lug and groove of the labyrinth seal on the links are designed in such a way that a sufficient, preferably maximum possible, overlap is achieved in the direction of chain pull, which in turn can ensure that the labyrinth seal itself can be configured to transmit corresponding tensile forces.

[0012] The penetration of contaminants into the joint area of ​​a chain can be delayed by labyrinths. These labyrinths can be implemented in the form of additional components, such as a multi-layer seal, or specially designed plates, such as grooves and lugs in the area of ​​the pitch holes, in combination with protruding bushings. The air gap within these labyrinths must be adjusted taking into account the joint play and any wear on the chain components.

[0013] If the chain is overloaded, i.e. if the chain tensile force is greater than the operating force, the links will elongate in the cross-sectional area of ​​the bores. As soon as this elongation exceeds the air gap between the labyrinth surfaces, the force flow within the chain is partially redirected via the labyrinth surfaces. This leads to less stress on the already deformed component areas (pins, bushings, head areas of the inner and outer links). In this way, the breaking force of a chain can be optimized. The coordination of the air gaps within the labyrinths should preferably be adjusted taking into account the deformation capabilities of the materials used. By using high-strength yet deformable materials, such as 42CrMo4, the power transmission capabilities of the labyrinths can be maximized.

[0014] Further advantageous embodiments of the proposed invention emerge in particular from the features of the subclaims. The subject matter and features of the various claims can, in principle, be combined with one another in any desired way.

[0015] In an advantageous embodiment of the invention, it can be provided that the width of the at least one nose and / or groove is designed in a thickness that is in the range of 80% to 120% of the nose length or groove depth.

[0016] In a further advantageous embodiment of the invention, it can be provided that the corners and edges of the at least one nose and / or groove are each designed with identical radii or chamfers, or at least approximately identical radii or chamfers. This allows the load-bearing area to be enlarged.

[0017] In a further advantageous embodiment of the invention, the radial clearance between the at least one groove and nose in the labyrinth can be between 0.6 and 2.25 mm. Relative to the typical clearance in a chain joint of between 0.4 and 1.5 mm, depending on the ambient conditions, the clearance between the groove and nose in the labyrinth should be approximately 50% larger. This ensures that the labyrinths do not touch under normal operating load. The axial clearance can be set identically.

[0018] In an advantageous embodiment of the invention, the labyrinth seal can be designed with an undercut, in particular with at least one groove and nose being dovetail-shaped. The chain tensile force and the unavoidable bending of the bolts create a force component that exerts axial stress on the outer link plate. This can lead to the outer link plate being pulled off the bolt. With the above-mentioned measure, the labyrinths, with a suitable design, can optimize the axial securing of the bolts.

[0019] It is provided that the outer link plate has a section offset from the center of the chain, wherein the offset section is arranged in a central region of the outer link plate between the chain joints.

[0020] Due to the chain tensile force, the components of the link chain involved in the force flow are deformed purely elastically up to a certain force. This deformation influences the contact between the link bushing and the chain pin. Due to the deflection of the pin, the contact shifts to the outer area of ​​the bushing bore. This effect intensifies as the chain tensile force increases. For mathematical purposes, it can be assumed that there is point contact between the bushing and the pin.

[0021] Due to the interference fit between the pins and the outer plates, the outer plate is also deformed by the bending of the pin. This results in the outer plate bending toward the center of the chain. This results in tensile stresses in the outer plate on the side facing the center of the chain and compressive stresses on the side facing outward. These stresses overlap with the tensile stresses within the plate, which result from the chain tensile forces.

[0022] As already explained, the bending stresses in the outer plates are reduced by having a section of the outer plate offset from the center of the chain. This measure allows the center axis of the section to pass through the point of force transmission between the bushing and the pin expected under tensile load of the link chain. As a result, superimposed bending stresses in the described section are either prevented from occurring at all or are reduced to a minimum.

[0023] It can be provided that the outer flap and / or the inner flap is designed to be tapered.

[0024] Typically, the link plates have different cross-sections perpendicular to the chain alignment. In the area of ​​the holes, the cross-sectional areas are significantly reduced. The central area of ​​the link plate, however, has a considerably larger cross-sectional area. The goal is to adjust the cross-sectional areas so that approximately equal stress distributions are achieved.

[0025] To achieve this, it is suggested that the link plate be tapered accordingly so that the cross-sectional areas perpendicular to the chain tension direction converge in large areas of the link plate. This distributes the stresses in the central area of ​​the link plate more evenly across the entire cross-section.

[0026] It can be provided that the inner link plate and / or the outer link plate is equipped with at least one reinforcement, wherein two reinforcements are arranged on each of the link plate heads of the inner link plate and / or the outer link plate, spaced apart from each other and from the longitudinal axis of the inner link plate and / or the outer link plate. In particular, the reinforcement can be designed as a thickening of the link plate wall on the side of the bore facing away from the link center.

[0027] The reinforcement is preferably arranged at an angle of 20° to 50°, more preferably between 25° and 40°, relative to the longitudinal axis of the link plate and the center of the bore in or on the link plate head segment. The reinforcement can be designed as a simple thickening or material reinforcement. In other words, the link plate head is thicker in the range of 20° to 50°, more preferably between 25° and 40°, than in the remaining ranges from 0° to 20° or 50° to 90°. The 0° angle is assumed to be the longitudinal axis of the link plate.

[0028] Regarding the extent of reinforcement, the cross-section of the link plate at the transition from the link plate head segment to the inner link plate can be used, such that the cross-section of the thickened portion, measured at the cross-sectional area with the largest radius through the reinforced area, should be 5% to 25%, preferably 10% to 18%, larger than the bore wall cross-section of the respective link plate head segment. In other words, the cross-section resulting from a section through the reinforcement at the point of the largest radius from the center of the bore to the outer edge of the link plate, in particular of the reinforced link plate head segment, should be 5% to 25%, preferably 10% to 18%, larger than the bore wall cross-section of the reinforced link plate head segment.

[0029] These designs can of course be transferred to the reinforcement of the other link head segments.

[0030] The cross-sectional areas of the link plates are inevitably weakened by the holes required to insert the bushings and bolts in the area of ​​the link plate heads. The transmission of chain tensile forces results in increased stress concentrations in this critical cross-section, as well as in the head area of ​​the link plates.

[0031] By locally reinforcing this area of ​​the link plates, the breaking force can be increased for specified chain dimensions (bushing, pin diameter, link plate height, link plate thickness, link plate length, pitch, etc.).

[0032] It can be provided that the cross section perpendicular to the longitudinal axis of the at least one inner link plate and / or the at least one outer link plate along the longitudinal axis of the link plate deviates from each other by less than 20%, preferably less than 10%, and more preferably is identical.

[0033] During operation, malfunctions, overload situations, or other influences may necessitate chain elongation. These length changes are distributed within the chain to the areas with the lowest stiffness. If this load occurs repeatedly, there is a risk of material fatigue at these locations.

[0034] Due to the large holes in the head area of ​​the link plates (to accommodate the bushings and bolts), the smallest cross-sections and thus the stiffness of the link plates can be found in this area.

[0035] Material fatigue can be counteracted by the above-mentioned measure. For the remaining link plate, link plate cross-sections should be selected that correspond to the cross-sections in the critical area, i.e., the area in the center of the link plate bore. The desired deviations between the individual cross-sectional areas are approximately 20%.

[0036] Preferably, deviations of less than 10% should be maintained; even more preferably, the individual cross-sectional areas should be identical. Sections with identical or nearly identical cross-sections should be as continuous as possible in the longitudinal direction of the plate.

[0037] The chain components, especially the inner and / or outer plates, can thus be designed to be as homogeneous as possible in terms of stiffness. This distributes necessary length changes during operation over larger areas of the chain, thus reducing the risk of material fatigue.

[0038] Due to the structural and geometric characteristics of a chain, the link plates are particularly important to consider. Through the waisting process described above, the cross-section of the link plate in the middle area can be significantly reduced, bringing it closer to the cross-section in the area of ​​the holes, and in some cases, even smaller.

[0039] In addition, the stiffness can be adjusted using holes in the center of the link plates. This design is particularly useful when the outer contour of the link plates is fixed for specific reasons. This can result, for example, from the smooth transfer of forces across the link plates.

[0040] All of the measures suggested above can be implemented individually or in any combination on a link chain. They are also suitable for the inner and / or outer link plates of a link chain.

[0041] Further features and advantages of the present invention will become clear from the following description of preferred embodiments with reference to the accompanying drawings. Fig. 1 a conventional articulated chain with an indication of the line load between the pin and the bushing; Fig. 1a a conventional articulated chain with high tensile load and point-like force transmission between the pin and the bushing; Fig. 1b an articulated chain according to the invention with a section offset from the chain center; Fig. 2 a conventional outer link plate of an articulated chain; Fig. 2a a waisted outer link plate of an articulated chain according to the invention; Fig. 2b cross-section BMQ according to section XX; Fig. 2c cross-section LMQ according to section YY; Fig. 3 an inventive link plate with a reinforced contour in the area of ​​the link plate heads; Fig. 4 a cross-sectional view of an articulated chain with a labyrinth seal between the outer link plate and the inner link plate; Fig. 4a an enlarged view according to Fig. 4 ; Fig. 4b: A cross-sectional view of a link chain with a labyrinth seal between the outer plate and the inner plate with an inserted ring as a lug; Fig. 4c: Variants of groove and lug in the labyrinth seal; Fig. 5: A link chain designed as homogeneously as possible with regard to its rigidity; Fig. 5a: Representation of cross sections of a chain according to Fig. 5 ; Fig. 6 shows a perspective view of an articulated chain according to the invention.

[0042] The following reference symbols are used in the figures: 1Inner plate 2Outer plate 3Bushing 4Bolt 5Hole KMChain center axis / chain center line LLongitudinal link axis / longitudinal link line LMLink center axis / link center line LMQLink center axis cross-section BCenter of the bore BMBore center axis / bore center line BMQBore wall cross-section 11Point of force transmission 12Section of the outer link plate 13Section center line 14Line through point 11 YDistance between chain centerline and offset centerline ZPull direction SSlot load 21Waistline 22Removed area 31reinforced area / reinforcement / thickening 41Nose / Ring 42Groove LNLength of the nose TNDepth of the groove DAverage thickness of the tab BNWidth of the nose BUWidth of the groove 51Sidecut 52Recess

[0043] The structure of a link chain is well known to those skilled in the art. A link chain, in particular a bushing chain, is essentially composed of two elements arranged in a row. These elements are also referred to as inner and outer links. An outer link typically consists of two outer plates 2, which are connected by two pins 4. An inner link typically consists of two inner plates 1, which are connected by two bushings 3.

[0044] A bushing 3 and a pin 4 inserted into the bushing of adjacent chain links form a chain link. These links enable the articulated chain, for example, to wrap around the sprockets in the drive train. The aforementioned design forms a simple articulated chain. More plates per inner or outer link are, of course, also conceivable. Fewer plates per chain link are also conceivable, for example, in a block link or block link chain.

[0045] For orientation, some areas of the link plates or link chain will be defined in more detail. The following axes define geometric relationships.

[0046] The articulated chain has a chain center KM extending in the longitudinal direction of the articulated chain, which can be referred to as the chain center axis.

[0047] The inner plate 1 and / or the outer plate 2 each have at least two bores 5, 5a for receiving the bushings 3 and the bolts 4, respectively.

[0048] The inner plate 1 and / or the outer plate 2 each have a plate longitudinal axis L which extends centrally in the longitudinal direction of the plate.

[0049] The inner link plate 1 and / or the outer link plate 2 has a link center axis LM, which is arranged, preferably centrally, between the bores 5 and 5a, respectively, and is aligned perpendicular to the link longitudinal axis L.

[0050] The inner link plate 1 and / or the outer link plate 2 or their bores 5 and 5a, respectively, each have bore center axes BM 1 and BM 2, respectively, which pass through the center of the bores and are aligned perpendicular to the link longitudinal axis L. The center of the bore 5 and 5a, respectively, shall be designated by the reference symbol B 1 and B 2, respectively.

[0051] Along the axes defined in this way, several cross-sections or areas arise which will be described in more detail below.

[0052] The link plate centerline LM defines a link plate centerline cross-section LMQ. Depending on whether the link plate has an opening in the center, a first link plate centerline cross-section LMQ 1 and a second link plate centerline cross-section LMQ 2 may result. LMQ is the sum of LMQ 1 and LMQ 2 or other partial cross-sections.

[0053] The bore center axes BM 1 and BM 2 delimit the middle area IL of the link plate from the link plate heads LK1 and LK2 respectively.

[0054] The longitudinal link axis L divides the link heads LK1 and LK2 into two link head segments each, in particular the first link head LK1 into the segments S1 and S2, and the second link head LK2 into the segments S3 and S4.

[0055] The respective link head segments are connected to the central or inner region IL of the link via bore wall cross-sections, corresponding to S1 with BMQ 1, S2 with BMQ 2, S3 with BMQ 3, and S4 with BMQ 4. The respective bore center axis BM 1 or BM 2 runs through the respective cross-sections, i.e. BM1 through BMQ 1 and BMQ 2, or BM2 through BMQ 3 and BMQ 4.

[0056] For a link chain, measures are proposed to increase the chain tensile force, or at least maintain the same chain tensile force, while reducing weight, particularly while maintaining or largely maintaining the other dimensioning parameters of the link chain. This increases the chain's cost-effectiveness and conserves resources.

[0057] A first measure is the offset of a section 12 of the link plate or links, preferably the middle section, in particular the outer link plate, in the direction of the chain center KM.

[0058] The initial situation is as follows. A conventional link chain is Fig. 1 shown.

[0059] Theoretically, and without considering elastic deformation, the transmission of a tensile force between the bolt and the bushing occurs as a pure distributed load. This is indicated by the arrows S in Fig. 1 The direction of pull is also indicated by the arrow Z.

[0060] Due to the chain tensile force, the components of the link chain involved in the force flow are deformed purely elastically up to a certain force. This deformation influences the contact between the joint bushing and the chain pin. Due to the deflection of the pin, the contact shifts to the outer area of ​​the bushing bore. This effect increases with increasing chain tensile force. Calculations can be based on a point-like contact between the bushing and the pin. The resulting position or point of force transmission is defined in the Fig. 1a represented by the point with the reference number 11.

[0061] Due to the interference fit between the pin and the outer link plate, the outer link plate is also deformed by the bending of the pin. This results in the outer link plate bending toward the chain center (KM). This results in tensile stresses in the outer link plate on the side facing the chain center (KM) and compressive stresses on the side facing outward. These stresses overlap with the tensile stresses within the link plate, which result from the chain tensile forces.

[0062] According to the invention, a section 12 of the outer link plate is offset in the direction of the chain center axis KM. Such an inventive link chain is Fig. 1b shown.

[0063] This allows, in particular, the bending stress in the outer link plate 2 to be reduced. This increases the chain tensile force and the efficiency of the link chain, while conserving resources. The offset section 12 has a section centerline 13 that runs parallel to the chain centerline KM. Furthermore, a line 14 is drawn through point 11, which should also run parallel to the section centerline 13 or the chain centerline KM. The vertical distance between line 14 and the section centerline 13 is indicated by the reference symbol Y.

[0064] The amount by which the above-mentioned offset should occur can be defined based on the section centerline 13 of the offset section 12 in relation to the force transmission point 11 outlined above in the elastic deformation case. The effect of reducing bending stresses in the outer link plate is greater the more precisely the section centerline 13 of the offset section 12 passes through the force transmission point 11, or in other words, the smaller the distance Y, the greater the effect of reducing bending stresses in the outer link plate.

[0065] In other words, the section center line 13 preferably passes exactly through the force transmission point 11 or at least approximately.

[0066] Furthermore, the effect of the reduction is greater the closer the offset section can be brought to the chain joint, although the offset cannot, of course, be realized in the area of ​​the link plate heads due to geometric reasons.

[0067] The chain tensile force of a link chain can also be increased by the following measure, in particular while maintaining or largely maintaining the other dimensioning parameters of the link chain, or at least the same chain tensile force can be achieved with reduced weight.

[0068] The shape of a usual tab is in the Fig. 2 The different cross-sections perpendicular to the chain alignment are also shown. In the area of ​​holes 5, the cross-sectional areas BMQ are significantly reduced. The central area of ​​the link plate, however, has a considerably larger cross-sectional area LMQ. The goal is to adjust the cross-sectional areas BMQ and LMQ in such a way that approximately equal stress distributions are achieved.

[0069] The following measure is proposed for this purpose. By selecting suitable manufacturing processes (forging, laser cutting, water jet cutting, etc.), the contour of the link plate can be designed as desired. By removing the areas with minimal stress, a tapered shape of the link plate results. In the figures, the contour of the waist is marked with the reference numeral 21, and the removed areas are indicated by the dot-dash line 22. The waist is designed in such a way that the cross-sectional areas perpendicular to the chain tension direction approach the link plate in large areas. Fig. 2a A waisted outer flap is shown schematically in a top view. In Fig. 2b is a cross section BMQ 1 and BMQ 2 according to section XX and in Fig. 2c Accordingly, a cross-section LMQ according to section YY is shown. It should preferably apply that BMQ 1 + BMQ 2 should be equal to or approximately equal to LMQ. Or, expressed differently, Q(L), with L in the longitudinal direction of the plate, should be constant or approximately constant.

[0070] The stress distribution within a link plate wraps around the holes in the link eyelets. In the center of the link plate, the stresses are distributed more evenly across the entire cross-section.

[0071] The chain tensile force of a link chain can also be increased by the following measure, in particular while maintaining or largely maintaining the other dimensioning parameters of the link chain, or at least the same chain tensile force can be achieved with reduced weight.

[0072] The reason for this is that the cross-sectional areas of the plates are inevitably weakened by the holes required to insert the bushings and bolts in the area of ​​the plate heads. The transmission of chain tensile forces results in increased stress concentrations in these cross-sections, known as critical cross-sections, in the head area of ​​the plates.

[0073] By locally strengthening the link plate heads LK1 or LK2 of the inner and / or outer plates, the breaking force can be increased for specified chain dimensions (bushing and pin diameter, plate height, plate thickness, plate length, pitch, etc.). Such an optimized inner plate can, for example, Fig. 3 have the contour shown. The reinforcement area is marked with reference numeral 31. The radius of the head area of ​​such a tab can be defined as a function around the center of the bore using the angle α as a running coordinate.

[0074] It can be seen that the outer link plate and / or the inner link plate is provided with at least one reinforcement 31, in particular that each link plate head segment S1 to S4 is provided with a reinforcement 31 to 31c.

[0075] The position and extent of the reinforcement can be described in more detail using the first reinforcement 31 on the first tab head segment S1.

[0076] The reinforcement 31 is preferably arranged at an angle α 1 of 20° to 50°, more preferably between 25° and 40°, relative to the longitudinal axis L of the link plate and the center point B of the bore 5 in or on the link plate, in particular on the outer side of the link plate head segment S1. The longitudinal axis L of the link plate accordingly defines the angle 0°.

[0077] With regard to the extent of the reinforcement 31 as a thickening of the link head segment S1, the bore wall cross-section BMQ 1 between the inner link IL and the first link head segment S1 can be used. As already explained above, the bore wall cross-section BMQ 1 should be arranged centrally and vertically above the bore. Based on this cross-section, it is preferably provided that the cross-section of the reinforced area, in each case radially starting from the respective bore center point B, should be 5% to 25%, preferably 10% to 18%, larger than the bore wall cross-section BMQ 1 of the respective reinforced link head segment. In other words, the cross-section Q r(α1) of the reinforced wall should be 5% to 25%, preferably 10% to 18%, larger than the bore wall cross-section BMQ 1.

[0078] These designs can, of course, be applied to the remaining reinforcements 31a to 31c. However, the cross-sections are always assigned to the respective holes and positions relative to the longitudinal axis of the plate and the central axis of the plate, i.e., BMQ 2 and Q r(α2), BMQ 3 and Q r(α3), and BMQ 4 and Q r(α4).

[0079] The chain tensile force of a link chain with at least one labyrinth seal in the area of ​​the chain joint can also be increased by the following measure, in particular while maintaining or largely maintaining the other dimensioning parameters of the link chain, or at least the same chain tensile force can be achieved with reduced weight.

[0080] The penetration of contaminants into the joint area of ​​a chain can be delayed by labyrinths. These labyrinths can be implemented in the form of additional components (e.g., a multi-plate seal) or specially designed plates (grooves and lugs in the area of ​​the pitch holes) in combination with protruding bushings. The air gap within these labyrinths must be adjusted taking into account the joint play and any wear on the chain components.

[0081] To increase the chain tensile force, it is proposed that the nose 41 and the groove 42 of the labyrinth seal on the plates be designed in such a way that corresponding overlaps are achieved in the direction of chain tension. For this purpose, it is proposed that at least one nose and groove be designed with a length or depth between 10% and 50% of the plate thickness, preferably in a range of 20% to 40% of the average plate thickness D of the respective plate. The respective plate refers to the plate in which the respective groove or nose is located.

[0082] These overlaps can also be created by additional elements. For example, a ring that is inserted into two grooves of the inner and outer link plates during assembly of the chain is conceivable. One such alternative is Fig. 4b shown.

[0083] A labyrinth seal of a link chain between the inner and outer plates in an unloaded initial state is in the Fig. 4 shown.

[0084] An enlarged view is available in the Fig. 4a The corresponding gap dimensions and width of the nose BN and the width of the groove BU are also shown here. The respective nose length LN and groove depth TN are also shown here.

[0085] It can be provided that the width of the at least one nose and / or groove is designed in a thickness that is in the range of 80% to 120% of the nose length LN or groove depth TN.

[0086] It can be provided that the corners and edges of the at least one nose and / or groove are each designed with identical radii or chamfers, or at least approximately identical radii or chamfers. This allows the load-bearing area to be enlarged.

[0087] The radial clearance between at least one groove and nose in the labyrinth can be specified to be between 0.6 and 2.25 mm. Based on a typical joint clearance between 0.4 and 1.5 mm, depending on the ambient conditions, the clearance between the groove and nose in the labyrinth should be approximately 50% larger. This ensures that the labyrinths do not touch under normal operating load. The axial clearance can be set identically.

[0088] If the chain is overloaded (chain tensile force >> operating force), the plates will elongate in the cross-sectional area of ​​the holes. As soon as this elongation exceeds the air gap between the labyrinth surfaces, the force flow within the chain is partially redirected via the labyrinth surfaces.

[0089] This leads to a lower load on the already deformed component areas (pins, bushings, head areas of the inner and outer plates). It is clear that not all parts can be relieved of load at the same time. However, it is possible to apply greater loads to the larger components in certain areas and relieve the weaker components. In this way, the overall breaking force of a chain can be optimized. The air gaps within the labyrinths must be adjusted to take into account the deformation capabilities of the materials used. By using high-strength yet deformable materials (e.g., 42CrMo4), the force transmission of the labyrinths can be maximized.

[0090] Depending on how the labyrinth is designed, different components (or component areas) in the chain strand can be relieved of load, for example the head area of ​​the inner link plate, the head area of ​​the outer link plate, the pin in the shear area.

[0091] The following preferred constellations have emerged in practice for relieving the burden on certain areas. 1. Groove in the inner plate / nose on the outer plate 1.1 identical play on both sides --> relieves bolt 1.2 increased play to the inside --> relieves bolt and head area of ​​the outer plate 1.3 increased play to the outside ---> relieves bolt and head area of ​​the inner plate Such constellations are shown from left to right in the figure Fig. 4c shown in the top row. 2. Nose on the inner plate / groove in the outer plate 2.1 Identical play on both sides --> relieves the bolt 2.2 Increased play towards the inside --> relieves the bolt and inner plate 2.3 Increased play towards the outside --> relieves the bolt and outer plate

[0092] Such constellations are shown from left to right in the figure Fig. 4c shown in the bottom row.

[0093] A further measure to improve a link chain, in particular to reduce material fatigue, is proposed below.

[0094] During operation, malfunctions, overload situations, or other influences may necessitate chain elongation. These length changes are distributed within the chain to the areas with the lowest stiffness. If this load occurs repeatedly, there is a risk of material fatigue at these locations.

[0095] Material fatigue can be counteracted by the following measures.

[0096] The articulated chain, in particular the inner plates and / or the outer plates, are designed to be as homogeneous as possible with regard to their rigidity in that the cross section perpendicular to the longitudinal axis L of the at least one inner plate 1 and / or the outer plate 2 along the longitudinal axis of the L of the plate deviates from each other by less than 20%, preferably less than 10%, and more preferably is identical. In other words, the tab center axis cross-section LMQ should be as large or, with a deviation of +- 20% or 10%, as large as the total bore wall cross-section BMQ 1 + BMQ 2 of a bore 5 or the total bore wall cross-section BMQ 3 + BMQ 4 of the other bore 5a, mathematically expressed LMQ = BMQ 1 + BMQ 2 +- 20% or +- 10% and / or LMQ = BMQ 3 + BMQ 4 +- 20% or +-10%.

[0097] This distributes necessary length changes during operation over larger areas of the chain and thus reduces the risk of material fatigue.

[0098] The cross-section LMQ can be adjusted accordingly using material recesses, which, for example, lead to a tapered or cutout-shaped link plate. In particular, if a recess in the form of a link plate opening is used to adjust the cross-section LMQ, the cross-section is then composed of the cross-sections LMQ 1 and LMQ 2, for example in the case of a central opening. In this way, the stiffness can be adjusted using opening(s) in the central link plate areas. This design is particularly useful when the outer contour of the link plates is fixed for specific circumstances. This can result, for example, from the smooth transfer of forces across the link plates.

[0099] A joint chain that is as homogeneous as possible in terms of stiffness is Fig. 5a shown. In the Fig. 5 corresponding cross-sections are indicated.

[0100] An inventive articulated chain in which all the measures outlined above have been implemented is described in Fig. 6 All of the measures suggested above can be applied individually or in any combination to a link chain. They are also suitable for the inner and / or outer link plates of a link chain.

Claims

1. Articulated chain, comprising at least - one inner tab (1), - one outer tab (2), - one bush (3) and one pin (4) which form a chain joint, wherein a labyrinth seal, which comprises at least one lug (41) and at least one groove (42), is provided between the outer tab (2) and the inner tab (1), wherein the at least one lug (41) and the at least one groove (42) are configured to have a length (LN) or depth (TN) of between 10% and 50% of the average respective tab thickness (D), preferably within a range of between 20% and 40% of the respective average tab thickness (D), and wherein the labyrinth seal is formed such that if the articulated chain is overloaded, the force flow inside the articulated chain is diverted in part via the labyrinth surfaces formed by the at least one lug (41) and the at least one groove (42), wherein the at least one groove (42) is formed in the inner tab (1) and the at least one lug (41) is formed on the outer tab (2) or wherein the at least one groove (42) is formed in the outer tab (2) and the at least one lug (41) is formed on the inner tab (1), and characterized in that the articulated chain has a chain center (KM) which extends in the longitudinal direction, and wherein the outer tab (2) has a portion (12) offset relative to the chain center (KM), wherein the offset portion (12) is arranged in a central region of the outer tab (2) between the chain joints.

2. Articulated chain according to claim 1, characterized in that the width (BN or BU) of the at least one lug (41) and / or groove (42) has a thickness which is within the range of between 80% and 120% of the lug length (LN) or groove depth (TN).

3. Articulated chain according to any one of claims 1 or 2, characterized in that the radial play between the at least one groove (42) and lug (41) in the labyrinth is between 0.6 and 2.25 mm.

4. Articulated chain according to any one of claims 1 to 3, characterized in that the corners and edges of the at least one lug (41) and / or groove (42) are each configured with identical radii or chamfering, at least, however, approximately identical radii or chamfering.

5. Articulated chain according to any one of claims 1 to 4, characterized in that the labyrinth seal is designed to be undercut, in particular in that the at least one groove (42) and lug (41) are designed as a dovetail.

6. Articulated chain according to any one of claims 1 to 5, characterized in that the offset portion has a portion center line (13) parallel to the chain center (KM), wherein, in the case of a chain under tensile force, the transmission of force between bush (3) and pin (4) is concentrated at a force transmission point (11), wherein the portion center line (13) passes through the force transmission point (11) or the portion center line (13) passes approximately through the force transmission point (11).

7. Articulated chain according to any one of claims 1 to 6, characterized in that the outer tab and / or the inner tab is designed in a tapered manner.

8. Articulated chain according to any one of claims 1 to 7, characterized in that the inner tab (1) and / or the outer tab (2) is provided with at least one reinforcement (31), wherein two reinforcements (31, 31a, 31b, 31c), which are spaced from one another and from the longitudinal axis (L) of the inner tab (1) and / or of the outer tab (2), are arranged on each of the tab heads (LK1, LK2) of the inner tab (1) and / or the outer tab (2).

9. Articulated chain according to any one of claims 1 to 8, characterized in that - the inner tab (1) and / or the outer tab (2) each have at least two bores (5, 5a) in the region of the tabs heads for receiving the bush (3) or the pin (4), wherein - the inner tab (1) and / or the outer tab (2) each have a tab longitudinal axis (L), wherein - the inner tab (1) and / or the outer tab (2) each have a tab center axis (LM) which is arranged, preferably centrally, between the bores (5, 5a) and is aligned perpendicular to the tab longitudinal axis (L), wherein - the inner tab (1) and / or the outer tab (2) each have bore center axes (BM1, BM2) which pass through the center (B1 or B2) of the bores (5, 5a) and are aligned perpendicular to the tab longitudinal axis (L), wherein - the bore center axes (BM1, BM2) each delimit a first tab head (LK1) and a second tab head (LK2) from the interior region (IL) of the tab, wherein - the tab longitudinal axis (L) divides the first tab head (LK1) into a first tab head segment (S1) and a second tab head segment (S2) and the tab longitudinal axis (L) divides the second tab head (LK1) into a third tab head segment (S3) and a fourth tab head segment (S4), wherein - the tab head segments (S1, S2, S3, S4) each have a bore wall cross-section (BMQ1BMQ1, BMQ2BMQ2 BMQ3, BMQ3, BMQ4 BMQ4), through which they are connected to the interior region (IL) of the tab, through which the respective bore center axis (BM1BM1 or BM2 BM2) passes.

10. Articulated chain according to any one of claims 8 or 9, characterized in that the reinforcement (31 or 31a to 31c) is arranged in or on the tab, in particular in or on the tab head, preferably in or on the tab head segment within the range of an angle a of between 20° and 50°, further preferably B2within the range of between 25° and 40°, relative to the longitudinal axis L of the tab and the center point B1(B1 or B2) of the bore (5 or 5a).

11. Articulated chain according to any one of claims 8 to 10, characterized in that the reinforcement (31, 31a, 31b, 31c) is designed as a thickening of the inner tab (1) and / or outer tab, in particular of the tab head (LK1, LK2), preferably of the tab head segment (S1, S2, S3, S4).

12. Articulated chain according to any one of claims 8 to 11, characterized in that the cross-section of the reinforcement (Qrx), in each case proceeding radially from the respective bore center point B, is between 5% and 25%, preferably between 10% and 18%, greater than the bore wall cross-section (BMQx) of the respectively reinforced tab head segment.

13. Articulated chain according to any one of claims 1 to 12, characterized in that the cross-section perpendicular to the longitudinal axis (L) of the at least one inner tab (1) and / or of the at least one outer tab (2) deviate by less than 20%, preferably by less than 10%, from one another, along the longitudinal axis (L) of the tab, further preferably are identical.

14. Articulated chain according to claim 13, characterized in that the cross-section is adjusted as a result of tapering (51) and / or recesses (52) of the at least one inner tab (1) and / or the at least one outer tab (2).