fastening element

Abstract

The invention relates to a fastening element (1), in particular a mounting bolt, comprising a fixing section (10), an intermediate section (20) and a mating section (30), wherein the fastening element (1) extends along a longitudinal axis (L), wherein the fixing section (10) has a fixing structure, in particular a thread, wherein the intermediate section (20) is arranged between the fixing section (10) and the mating section (30) in the direction of the longitudinal axis (L), wherein the mating section (30) is essentially rotationally symmetrical around the longitudinal axis (L), wherein the mating section (30) has an outer load-bearing surface (34), wherein the load-bearing surface (34) has a clearance fit, and wherein lubricating grooves (32) are present at least in the mating section (30).

Description

[0001] The present application is a divisional application of the application with international application date 22 July 2020, national application number 202080055257.0 (international application number PCT / EP2020 / 070629) and the title “Fastening element”. TECHNICAL FIELD

[0002] The present application relates to a fastening element, in particular a clearance fit fastening element. BACKGROUND

[0003] Fastening elements are already known from the prior art. The elements serve to connect two components to one another such that forces can be transmitted from one component to the other. The fastening elements are here usually designed in such a way that the components to be fastened can move relative to one another. This is achieved, inter alia, by a clearance fit between the elements to be fastened and the fastening element. However, precisely when the elements to be fastened are precisely guided, there can often be certain movement difficulties between the components to be fastened and the fastening element, in particular movement difficulties caused by the ingress of corrosion and / or occurring friction. SUMMARY

[0004] It is therefore an object of the present application to provide a fastening possibility which enables easy movement.

[0005] The object is achieved by means of the mounting element according to the application, the mounting system according to the application and the manufacturing method according to the application.

[0006] According to the invention, the fastening element, in particular a mounting bolt, comprises a fixing section, an intermediate section and a mating section, wherein the fastening element extends along a longitudinal axis, wherein the fixing section has a fixing structure, in particular a thread, wherein the intermediate section is arranged between the fixing section and the mating section in the direction of the longitudinal axis, wherein the mating section is substantially rotationally symmetrical about the longitudinal axis, and wherein the mating section has an outer load- bearing surface, wherein the load-bearing surface has a clearance fit, and wherein at least one lubricating groove is present in at least the mating section. The fastening element according to the invention is in particular used to connect a mounting part and a fixing part, such that the mounting part and the fixing part can move relative to one another along the longitudinal axis, however, wherein forces perpendicular to the longitudinal axis or axis of movement can be absorbed or transmitted by the fastening element. In other words, the fastening element according to the invention can be used to achieve a fastening, wherein between the parts to be fastened (mounting part and fixing part) movement is possible, at least to some extent, in the direction of the longitudinal axis of the fastening element. The longitudinal axis of the fastening element is the axis along which the fastening element mainly extends. In other words, the longitudinal axis is in particular the axis along which the length of the fastening element is determined. The fastening element has at least one fixing section, an intermediate section and a mating section. The fixing section serves to connect the fastening element to the fixing part, for example in a form-fit. The connection is advantageously achieved here such that, in the mounted state, relative movement between the fixing part of the fastening element and the fixing section is not possible. In order to achieve the fixing, the fixing section in particular has a fixing structure. For example, the fixing structure can be formed here by an external thread. Alternatively or additionally, the fixing structure can also preferably consist of an internal thread. However, the fixing structure is generally to be understood as any structure which can achieve a secure connection of the fixing section of the fastening element to the fixing part. For example, such a fixing structure can also be produced by a reforming process, such as by crimping a part of the fixing section. The intermediate section of the fastening element is arranged between the fixing section and the mating section, viewed in the direction of the longitudinal axis. The intermediate section is advantageously at least section-wise rotationally symmetrical about the longitudinal axis. For example, the intermediate section can be at least partially conically and / or cylindrically configured, in order thus to cause a change in geometry in the direction of the longitudinal axis. This can be used, for example, to achieve a gentle transition in the outer dimensions between the fixing section and the mating section, in order to achieve a mechanically loadable fastening element. The intermediate region is in particular designed here such that it tapers from the fixing section to the mating section. By this, a change in the bending stress process which mainly occurs along the longitudinal axis is taken into account, such that material can be saved, however, wherein at the same time a sufficient bending stiffness or bending strength of the fastening element is present. The mating section of the fastening element is in particular used to interact with the mounting part directly or indirectly in contact. The mating section is achieved here such that it has an outer load-bearing surface which is designed for direct or indirect contact with the mounting part.In order to realize the movability of the fastening element along the longitudinal axis with respect to the mounting portion, the bearing surface is designed in such a way that it has a clearance fit, in particular with respect to a face of the mounting portion, which can surround and / or contact the fitting section of the fastening element in the mounted state. For example, the fitting can be designed in such a way that it is in a tolerance class IT4 to IT11 according to DIN ISO 286-1. The fitting section is here essentially rotationally symmetrical about the longitudinal axis. "Essentially rotationally symmetrical" is to be understood as meaning that the basic shape of the fitting section, in particular the bearing surface of the fitting section, is rotationally symmetrical about the longitudinal axis, for example at least partially conically or cylindrically or tri- or penta-lobed. Here, in particular when the bearing surface of the fitting section is calibrated tri-lobed and has an outer diameter tolerance of ≤ 30 μιη and a tri-lobedness of 10 μιη to 100 μιη, the fitting section is essentially rotationally symmetrical. Alternatively, preferably or additionally preferably, the fitting section can also be essentially rotationally symmetrical when the bearing surface of the fitting section has a bearing surface calibrated penta-lobed with an outer diameter tolerance of ≤ 30 μιη and a defined out-of-roundness of 10 μιη to 100 μιη. However, said essential rotational symmetry of the fitting section, in particular the bearing surface of the fitting section, can in particular be disrupted by lubrication grooves or recesses leading to lubrication grooves without violating the fitting section being "essentially rotationally symmetrical". In other words, this can mean that the fitting section can essentially be conical, cylindrical or barrel-shaped, wherein one / more lubrication groove(s) or lubrication spiral(s) can be introduced into said ideal, rotationally symmetrical shape about the longitudinal axis without disrupting the essentially rotationally symmetrical shape of the fitting section. In the fitting section according to the application, one or more lubrication grooves are introduced into the bearing surface, which, as already described, can interfere with the rotationally symmetrical design of the fitting section. The lubrication grooves here serve to be able to accommodate lubricating material and to enable the entry of lubricant into the region of the contact of the fitting section, in particular the bearing surface. Thereby, in particular a reduction in the coefficient of friction is achieved, so that the fastening element according to the application enables an easy mounting of the fastening element with respect to the mounting portion. In addition, it is also possible to prevent or make difficult corrosion, in particular fitting-induced corrosion, in the long term, so that the clearance fit "easy to move" can also be maintained over a long period of time. The lubrication grooves in the fitting section can here be rotationally symmetrical about the longitudinal axis.

[0007] For example, this is possible in the case of a design of the lubricating grooves which is closed in itself and annular. Alternatively, preferably or additionally preferably, the lubricating groove or all lubricating grooves can also be designed in such a way that they run completely through the mating section in the direction of the longitudinal axis or extend completely in the longitudinal direction over the mating section. This is the case, for example, when the lubricating grooves extend over the entire mating section along the longitudinal axis. For example by straight-line designed lubricating grooves. By having the lubricating groove or at least some of the lubricating grooves run along the entire mating section in the direction of the longitudinal axis, external addition of lubricant can also be achieved in the mounted state, and, in addition or alternatively, a reliable lubrication of the entire mating section in the direction of the longitudinal axis can also be achieved thereby.

[0008] The lubricating material is advantageously introduced in one or more lubricating grooves. In one preferred embodiment, different lubricants are introduced in at least two different lubricating grooves. Thereby, the lubricating material in the respective lubricating groove can be adapted to the existing friction load profile of the respective groove.

[0009] The at least one lubricating groove, in particular all lubricating grooves, is advantageously designed and / or configured in such a way that the bearing surface can be wetted by the lubricating groove with lubricant when the fastening element is moved in the direction of the longitudinal axis. In other words, this can mean that the lubricating groove can be shaped or provided in such a way that the bearing surface can be wetted by the lubricant not only in the circumferential direction around the direction of the longitudinal axis but also in the direction of the longitudinal axis by means of the lubricating groove. The wetting can here interact directly or indirectly with the receiving portion of the mounting portion, for example. In other words, the lubricating groove can thus be provided and / or configured in such a way that it can deliver or transport lubricant to any location of the bearing surface when the fastening mechanism is moved in the direction of the longitudinal axis. However, it can be necessary here that such a lubricant delivery and / or such a lubricant transport can be achieved not only by the lubricating groove but also for this purpose a contact partner, for example a receiving portion of the mounting portion, which cooperates with the lubricating groove. For example, such a lubricating groove can be achieved in that the lubricating groove is configured as a lubricating spiral.

[0010] Advantageously, the at least one lubricating groove, in particular all lubricating grooves, is a lubricating spiral. A lubricating spiral is to be understood as meaning that the lubricating groove is introduced into the mating section in a spiral shape. In other words, the lubricating spiral can be designed similar to a thread. By providing at least one lubricating spiral, a particularly uniform and good distribution of the lubricant is achieved not only in the longitudinal direction but also in the circumferential direction.

[0011] Advantageously, the lubricating groove, in particular the lubricating helix, has a helix pitch in the direction of the longitudinal axis, wherein the helix pitch of the lubricating groove is in the range of 0.03 to 0.4, preferably in the range of 0.05 to 0.3, and particularly preferably in the range of 0.075 to 0.2, relative to the diameter of the bearing surface. The stated proportions here in particular relate to a single- or multi-headed lubricating helix. If one lubricating helix or a plurality of lubricating helices are configured multi- headed relative to one another, the proportions should advantageously be multiplied by the number of heads. The helix pitch of the lubricating groove here in particular is the spacing of two adjacent, identically directed edges of the lubricating groove in the direction of the longitudinal axis. In other words, this can mean that the helix pitch of the lubricating groove is the spacing of the lubricating groove relative to itself in the longitudinal direction after one revolution around the longitudinal direction. In the case of a proportion of 0.03 to 0.4, a particularly high load capacity of the bearing surface can be achieved. In the case of a proportion in the range of 0.05 to 0.3, the applicant surprisingly found that such a bearing surface or lubricating groove can be produced particularly simply. In the case of a proportion in the range of 0.075 to 0.2, the applicant found that a particularly uniform distribution of the lubricant in the lubricating gap can be achieved.

[0012] Alternatively or additionally, preferably, the spacing of two adjacent lubricating grooves in the direction of the longitudinal axis is in the range of 0.03 to 0.4, preferably in the range of 0.05 to 0.3, and particularly preferably in the range of 0.075 to 0.2, relative to the diameter of the bearing surface. In the case of a proportion of 0.03 to 0.4, a particularly high load capacity of the bearing surface can be achieved. In the case of a proportion in the range of 0.05 to 0.3, the applicant surprisingly found that such a bearing surface or lubricating groove can be produced particularly simply. In the case of a proportion in the range of 0.075 to 0.2, the applicant found that a particularly uniform distribution of the lubricant in the lubricating gap can be achieved.

[0013] Preferably, the width, in particular the average width, of the lubricating groove in the direction of the longitudinal axis is in the range of 0.003 to 0.1, preferably in the range of 0.005 to 0.05, and particularly preferably in the range of 0.009 to 0.03, relative to the helix pitch of the lubricating groove. In the case of a proportion of 0.003 to 0.1, a particularly high load capacity of the bearing surface can be achieved. In the case of a proportion in the range of 0.05 to 0.5, the applicant surprisingly found that such a lubricating groove can be produced particularly simply. In the case of a proportion in the range of 0.009 to 0.03, the applicant found that a particularly uniform distribution of the lubricant in the lubricating gap can be achieved. The decisive width of the lubricating groove in the direction of the longitudinal axis here advantageously is the average maximum width of the lubricating groove in a cross-sectional plane containing the longitudinal axis. In other words, the decisive cross-sectional plane can thus be a longitudinal cross-sectional plane.

[0014] Alternatively or additionally, preferably, the width, in particular the average width, of the lubrication groove in the direction of the longitudinal axis is in the range of 0.003 to 0.1, preferably in the range of 0.005 to 0.05, and particularly preferably in the range of 0.009 to 0.03, relative to the spacing of two adjacent lubrication grooves in the direction of the longitudinal axis. The spacing of two adjacent lubrication grooves in the direction of the longitudinal axis here can mean not only the spacing to another lubrication groove, but also the spacing of the lubrication groove from itself in the direction of the longitudinal axis. In other words, in the case of a single lubrication groove, the spacing can correspond to the pitch of the lubrication groove. The spacing of two adjacent lubrication grooves in the direction of the longitudinal axis is in particular the spacing of the center lines of the lubrication grooves on the bearing surface in the longitudinal section relative to one another. With a ratio of 0.003 to 0.1, a particularly high load capacity of the bearing surface can be achieved. With a ratio in the range of 0.005 to 0.05, the applicant has surprisingly found that such a lubrication groove can be produced particularly simply. With a ratio in the range of 0.009 to 0.03, the applicant has found that a particularly uniform distribution of the lubricant in the lubrication gap can be achieved.

[0015] The fastening element is advantageously configured in one piece. Thereby a fastening element can be realized which can be particularly loadable. One piece here is to be understood in that the fastening mechanism itself is made from the base body and / or the blank. Thus, the fastening mechanism is in particular not formed by a plurality of components which are joined, for example in a material-fit manner.

[0016] The fastening element is advantageously configured as a guide element. In other words, this can mean that the fastening mechanism serves for the transport of a component, in particular in the direction of the longitudinal axis.

[0017] The bearing surface is advantageously configured without threads. The configuration "without threads" here is to be understood in that the bearing surface does not have threads. Thereby a notch stress concentration effect in the bearing surface can be reduced, so that the loadability of the fastening element can be increased.

[0018] In an advantageous embodiment, the mating section has a plurality of lubricating spirals, wherein the mating section has in particular 3 to 20 lubricating spirals. The mating section can have, similar to in the case of a thread, a plurality of lubricating spirals, wherein the lubricating spirals can be designed multi-start with respect to one another. Thus, the mating section can have multi-start lubricating spirals, similar to in the case of a multi-start thread. Thus, by virtue of the provision of a plurality of lubricating spirals, a particularly simple distribution of lubricant can be achieved, in particular also because by virtue of the provision of a plurality of lubricating spirals the pitch of the lubricating spirals can be chosen particularly large. The length of the individual lubricating spirals can thereby be reduced, so that also lubricating materials of high viscosity can be introduced into the spirals effectively. The mating section has in particular 3 to 20 lubricating spirals. Thereby a particularly simple replenishment of lubricating material can be achieved. In other words, by virtue of the provision of 3 to 20 lubricating spirals it can be achieved that also after a start-up or after the installation of the fastening element, lubricant can be easily replenished into the gap mating gap to be lubricated between the bearing surface and the accommodation of the mounting portion. The case allows here, in particular also without disassembly of the fastening element, the exchange of lubricating material.

[0019] The bearing surface is advantageously designed cylindrically about the longitudinal axis. The bearing surface is in particular cylindrical if it is arranged between two imaginary cylinders having a diameter difference of 30 pm to a maximum of 100 pm, wherein the symmetry axes of the two imaginary cylinders are in particular on the longitudinal axis. By virtue of the cylindrical design of the bearing surface a particularly uniform stress distribution is achieved, so that the fastening element can safely absorb high transverse forces. Advantageously, the cylindrical design of the bearing surface can in particular be produced or achieved by calibrating the unprocessed profile in a subsequent production step, in particular by calibrating the unprocessed profile by rolling.

[0020] The cross-section of the lubrication groove preferably has an opening pointing in the radial direction and a base section, wherein the base section is rounded off in particular. The decisive cross-section for the determination here is the cross-section of the lubrication groove perpendicular to the direction of extent of the lubrication groove. The opening of the lubrication groove is designed in particular such that the opening realizes a contour on the bearing surface. In other words, this can mean that the radially outwardly pointing end of the lubrication groove constitutes the opening in particular. The radial direction here is the direction pointing away from the longitudinal axis radially. The base section of the lubrication groove is the section of the lubrication groove connecting the two edges of the lubrication groove to one another. The base section is rounded off in particular. The base section constituted in this way with a rounded-off radius results in a particularly simple production of the base section and, in addition, a particularly small notch stress concentration effect can be achieved thereby and a particularly high degree of strength can be achieved in conjunction therewith. Advantageously, the ratio of the rounded-off diameter of the rounded-off base section to the outer diameter of the bearing surface of the mating section is in the range of 0.025 to 0.05 here. A particularly mechanically robust and notch stress concentration effect low thread results in the case of this design. The rounding of the base section is designed in particular such that the rounding is greater than the rounding of a comparable metric thread.

[0021] In a preferred refinement, the opening has a smaller extension than the base section, in particular in the direction of the longitudinal axis. In other words, this can mean that the lubrication groove is constituted such that it tapers towards the opening. Thus, the lubrication groove can be designed such that in particular the part of the groove between the base section and the opening tapers towards the opening. By means of the tapering, a controlled lubricant outflow can be achieved. The tapered part in particular blocks a part of the lubricant such that a particularly uniform lubricant outflow along the extension of the lubrication groove is achieved.

[0022] In a preferred embodiment, the cross-section of the lubrication groove has an arrowhead-shaped connecting section, wherein the arrowhead-shaped connecting section tapers in the direction of the radial direction. The connecting section is the part or lateral part of the cross-section of the lubrication groove connecting the base section with the opening. The cross-section here is constituted straight in the connecting region in particular. Arrowhead-shaped is to be understood here in particular as meaning that the two connecting sections constituted in the shape of a leg taper in such a way that the parts or legs of the connecting sections would theoretically intersect outside the fastening element. In other words, the connecting section can be constituted at least partially in the shape of a V, wherein the (imaginary) intersection point of the two V-shaped legs would be outside the fastening element in the radial direction. This type of design of the connecting section is in particular particularly simple to produce, such that a cost-advantageous fastening element results thereby.

[0023] In one preferred refinement, the opening angle of the arrowhead-shaped connecting section has an angle in the range of 10° to 70°, preferably in the range of 20° to 60°, and particularly preferably in the range of 30° to 50°. The opening angle here is the angle formed between the legs of the arrowhead shape of the connecting section. In the case of an opening angle in the range of 10° to 70°, a lubrication groove is brought about which is particularly simple to manufacture, so that a cost-advantageous fastening element is brought about. In the case of an opening angle in the range of 20° to 60°, a particularly uniform lubricant distribution can be achieved, since in this design variant a lubricant of high viscosity can also be uniformly flowed out or introduced in the radial direction through the opening over the length of the lubrication groove into the gap to be lubricated. In the case of an opening angle in the range of 30° to 50°, a design variant is brought about in which the notching stress concentration effect of the cross section of the lubrication groove is particularly small, so that a particularly high mechanical strength of the fastening element can be achieved thereby.

[0024] Preferably, the ratio of the minimum diameter of the lubrication groove, in particular of the base section of the lubrication groove, to the diameter of the bearing surface is in the range of 0.8 to 0.98, preferably in the range of 0.85 to 0.95, and particularly preferably in the range of 0.88 to 0.92. The minimum diameter of the lubrication groove is measured in particular by the portion or region of the lubrication groove which is closest to the longitudinal axis. This is here in particular the base section of the lubrication groove. For determining the ratio, the diameter of the bearing surface is in particular the average diameter of the bearing surface along the longitudinal axis of the fitting section. In the case of a ratio of the diameter in the range of 0.8 to 0.98, a particularly high degree of uniformity of the lubricant within the lubrication groove and in the gap to be lubricated is brought about. In other words, in the case of the ratio, particularly much lubricant can be absorbed, so that a particularly long service life of the lubrication can be achieved thereby. In the case of a diameter ratio in the range of 0.85 to 0.95, a fitting section is brought about which has a particularly low degree of notching stress concentration effect. This is therefore in particular decisive, since a high notching stress concentration effect has a large influence on the mechanical strength of the fastening element in the case of bending loads. In the case of a diameter ratio of 0.85 to 0.95, a fastening element is therefore brought about which can be particularly subjected to mechanical loads. In the case of a diameter ratio in the range of 0.88 to 0.92, a fitting section is brought about which is particularly simple to manufacture, in particular by cold reshaping. A cost-advantageous fastening element can therefore be achieved thereby.

[0025] Advantageously, the bearing surface share of the mating section is in the range of 0.3 to 0.9 and / or 0.8, preferably in the range of 0.4 to 0.7, and particularly preferably in the range of 0.5 to 0.65. The bearing surface share of the mating section here is the portion of the surface which is assigned to the bearing. For example, the share can be determined by subtracting the portion of the surface which is formed by the lubricating groove or by the opening of the lubricating groove from the entire surface of the mating section. In other words, the bearing surface share can be determined by projecting the lubricating groove and the bearing surface onto a cylinder which just surrounds the mating section and then determining the share of the surface of the cylinder which is formed or covered by the projection of the bearing surface. In the case of a bearing surface share of the mating section in the range of 0.3 to 0.9 and / or 0.8, a particularly high bearing capacity of the fastening element or of the mating section can be achieved, since a particularly high degree of force and torque can thereby be absorbed by the bearing surface. In the case of a bearing surface share in the range of 0.4 to 0.7, a particularly simply manufacturable bearing surface is brought about. In the case of a bearing surface share of 0.5 to 0.65, a particularly good lubricant guidance can be achieved, since in the design of this type the majority of the mating section is constituted by the lubricating groove.

[0026] A lubricant, in particular a lubricating grease or a lubricating oil, is preferably present or introduced into the at least one lubricating groove. By means of the provision of a lubricant, a particularly simple lubrication can be achieved.

[0027] Advantageously, the fastening element is produced by cold forming. By producing the fastening element by means of cold forming, a positive material influence is achieved, since cold forming brings about a mechanical stiffening of the material, so that a cold-formed fastening mechanism is significantly more mechanically robust than a non-cold-formed fastening element.

[0028] Advantageously, the mating section constitutes an end section, in particular in the direction of the longitudinal axis of the fastening element. By making the mating section into an end section, a particularly simple production of the fastening element can be achieved. An end section is to be understood here as meaning that the mating section constitutes the last distal region of the fastening element, in particular in the direction of the longitudinal axis.

[0029] Alternatively, a stop section can preferably also extend behind the mating section, viewed in the direction of the longitudinal axis. By providing a stop section, it is possible to prevent possible relative movements between the fastening element and the mounting portion in the direction of the longitudinal axis in a form-fit manner. For example, such a stop section can be formed by a radially protruding stop. Advantageously, the radially protruding projection (stop section) here extends annularly around the longitudinal axis.

[0030] The fixing section preferably has a fixing structure in the form of an internal thread and / or an external thread. By virtue of the internal thread and / or the external thread, a particularly simple installation can be achieved. Alternatively or additionally, the fixing section preferably also has a tool engagement contour, for example an external hexagon, an internal hexagon or an internal hexagonal round. Thereby, the installation of the fastening element can be further simplified, in particular, since by virtue of the tool engagement contour, the use of further clamping tools for the installation can be avoided.

[0031] The fixing section advantageously constitutes an end section, in particular in the direction of the longitudinal axis of the fastening element. By virtue of the fixing section being provided as an end section, a geometry is achieved which is to be particularly simple to manufacture, since in particular in the case of a retrofit, the region in the end section can be machined more easily with a large degree of retrofit. Thus, by virtue of the fixing section being provided in the end region or end section of the fastening element, a fastening element is achieved which is to be particularly easy and cost-advantageously manufactured.

[0032] A further aspect of the application relates to a mounting system comprising a fastening element, in particular as described above and below, and a mounting part, wherein the mounting part has a receiving portion, wherein the fastening element has a mating section, wherein the mating section extends at least partially into the receiving portion or is designed for at least partial extension into the receiving portion, wherein the receiving portion and the mating section have a clearance fit relative to one another. In other words, the mounting element can have the above-mentioned properties and features of the fastening element, in particular with regard to the mating section. Alternatively, the fastening element can preferably also be designed such that there is no lubricating groove at all in the mating section. However, in this design, it is at least advantageous according to the application if the receiving portion of the mounting part has a lubricating groove. Said lubricating groove of the mounting part can here be designed such that it can have the above-mentioned properties and features of the lubricating groove of the fastening element. In other words, this can mean that the properties and features of the lubricating groove described in this document can also be implemented in the lubricating groove of the mounting part. It is particularly preferred when both the fastening element and the mounting part have a lubricating groove in the form of said lubricating spiral when the two lubricating spirals are oppositely configured relative to one another. Thereby, it can be achieved that the lubricating spiral of the fastening element is prevented from jamming with the lubricating spiral of the mounting part. The receiving portion of the mounting part is in particular a recess which is advantageously configured complementarily to the outer contour of the mating section of the fastening element. Said oppositely configured sections relative to one another are here in particular configured as a clearance fit relative to one another. In other words, this can mean that the fastening element with its mating section can be introduced into the receiving portion of the mounting part without contact in theory. By virtue of the mounting system according to the application, lubrication in the clearance between the mounting part, in particular the receiving portion of said mounting part, and the mating section of the fastening element can be achieved by means of the lubricating groove, which leads to a friction reduction in an effective manner.

[0033] The receiving portion of the mounting part is advantageously filled with a lubricating material, and / or the lubricating material or lubricant is present in the receiving portion. By introducing the lubricating material into the receiving portion, the receiving portion functions as a reservoir for providing the lubricating material. Furthermore, it is also possible to achieve, by means of each relative movement between the fastening element and the mounting part, the lubricating material can be introduced or delivered into one or more lubrication grooves by said movement.

[0034] Advantageously, the mating section of the fastening element can move freely relative to the receiving portion in the longitudinal axis direction when installed. In other words, the mating section is not designed such that it can prevent relative movement between the fastening mechanism and the receiving portion in the longitudinal axis direction by means of form fit or force fit. Therefore, in other words, the mating section can also be particularly threadless.

[0035] The mating section advantageously has an outer bearing surface, wherein at least one lubrication groove is present in the mating section. This lubrication groove is designed such that, when the fastening element moves in the direction of the longitudinal axis, the portion of the bearing surface and / or the receiving portion of the mounting part that contacts and / or can contact the mating section can be wetted by the lubrication groove with the aid of lubricant. In other words, this can mean that the lubrication groove is provided and / or designed such that the lubrication groove can wet the portion of the bearing surface or the receiving portion that contacts the bearing surface with lubricant by the longitudinal movement of the fastening element, particularly completely in the direction of the longitudinal axis and circumferentially around the longitudinal axis. This allows for particularly good and uniform lubricant distribution. This configuration of the lubrication groove can be achieved, for example, by a lubrication spiral. In other words, the lubrication groove can therefore be a lubrication spiral.

[0036] In one advantageous embodiment, the mounting portion is the brake caliper or a part of the brake caliper. This, in particular, prevents brake caliper adhesion through lubrication delivery via lubrication grooves, thereby increasing the service life of the brake caliper and the entire braking system.

[0037] A further aspect of the application relates to a production method for a fastening element, in particular a fastening element according to one of the above-mentioned design solutions, wherein the fastening element has a fitting section with a lubricating groove and a bearing surface, wherein the production method comprises the following steps: providing a blank; machining the blank, in particular by cold forming, wherein the lubricating groove is realized, in particular by machining or cold forming. The production method can in particular comprise the step of machining the blank to realize the fitting section with the lubricating groove and the bearing surface. By means of the production method according to the application, the fastening element can be produced cost- advantageously. In the case of machining the blank by means of cold forming, a fastening element is produced which can in particular be subjected to mechanical loads. The cold forming of the blank is here realized in particular such that, in the production method, the die and the punch move relative to one another in the direction of the longitudinal axis of the fastening element. The cold forming of the blank can here be carried out not only in one work step, but also in a plurality of staged, successive cold formings. The fixing structure or structure of the fixing section, in particular in the form of a thread, is advantageously produced directly during the cold forming. Thereby, a particularly advantageous production of the fastening element is brought about. Alternatively, the thread (or the plurality of threads) is preferably produced in a separate, subsequent rolling process. Thereby, a particularly precise production of the thread can be realized.

[0038] Preferably, in particular after the cold forming, the bearing surface of the fitting section is calibrated, in particular by rolling. By means of said calibration of the bearing surface, a particularly flat or cylindrical bearing surface can be realized. Additionally, by means of said calibration, it can also preferably be realized that the opening of the lubricating groove is slimmed. Thereby, it can additionally be made difficult for the lubricant to flow out of the lubricating groove. Advantageously, said calibration is here realized by means of rolling, since thereby a cost- particularly advantageous calibration with a particularly narrow tolerance class, in particular IT4 to IT7, can be realized. Advantageously, said calibration step is here carried out after the forming or cold forming of the workpiece blank, so that it can be regarded as a kind of finishing step. BRIEF DESCRIPTION OF DRAWINGS

[0039] Further advantages and features of the application result from the following description with reference to the drawings. Individual features of the embodiments shown can also be used in other embodiments, if this is not explicitly excluded. The drawings show:

[0040] Figure 1 a sectional view of a mounting system with a fastening element;

[0041] Figure 2 a detail view of a section of the fastening element;

[0042] Figure 3 a detail view of a section of the fitting section; and

[0043] Figure 4Another detail view showing a cross section of the fitting section of the fastening element.

[0044] Figure 5 Another detail view showing a part of the fastening element. DETAILED DESCRIPTION

[0045] In Figure 1 mounting system having a fastening element 1, a mounting part 100 and a fixing part 200. The fixing part 200 is indirectly firmly connected with the fixing section 10 of the fastening element 1. To this end, the fixing section 10 has a fixing structure in the form of an internal thread. The fastening element 1 extends along a longitudinal axis L, wherein the fixing section 10 and the fitting section 30 each constitute an end section of the fastening element 1 in the direction of the longitudinal axis L. The intermediate section 20 of the fastening element 1 extends between the fixing section 10 and the fitting section 30. The fitting section 30 of the fastening element 1 has lubricating grooves 32 which constitute a lubricating spiral and extend helically on the outside of the fitting section 30 around the longitudinal axis L. A bearing surface 34 is in an intermediate space between each lubricating groove 32 or between two adjacent parts of a lubricating groove 32. Said bearing surface serves here for direct contact with a receiving part 110 of the mounting part 100. By providing the fitting section 30 of the fastening element 1 with lubricating grooves 32 it is achieved that a lubricant can be introduced in an effective manner into the gap between the receiving part 110 and the fitting section 30. In order to enable a relative movement between the fitting section 30 and the receiving part 110, not only the fitting section 30 but also the receiving part 110 has a clearance fit.

[0046] In Figure 2 a detail view of a part of the fastening element 1 is shown. In principle, Figure 2 the detail section of the fastening element 1 shown in Figure 1 the fastening element 1 shown in Figure 2 It can be seen in Figure 2 that the lubricating grooves 32 extend on the outer surface of the fitting section 30. In principle, not only one lubricating groove 32 can be provided here, but also a plurality of lubricating grooves 32. For example, the lubricating grooves 32 can constitute here lubricating spirals 32 or also lubricating rings 32.

[0047] In Figure 3The image shows a detailed view of the cross-section of the mating section 30. (See image from...) Figure 3 As can be seen, especially when viewed in the longitudinal direction L, the bearing surface 34 extends between two lubrication grooves 32. The lubrication grooves 32 here have a bottom section 38. Figure 3 In the case shown, the extensions of the bearing surface 34 are respectively formed in an arc shape. This design configuration occurs, for example, especially when the bearing surface 34 is not calibrated.

[0048] exist Figure 4 The same detailed view of the cross-section of the mating section 30 is also shown. Figure 4 The situation illustrated involves a fastening element 1 whose bearing surface 34 has been calibrated by roll forming. For example, as... Figure 4 The situation shown can be calibrated. Figure 3 This is achieved as shown in the diagram. Figure 3 and Figure 4 The comparison shows that the calibration can achieve a significant configuration change in the lubrication groove 32 and the bearing surface 34. Figure 4 In the illustrated embodiment, the lubrication groove 32 is designed such that a bottom segment 38 with rounded corners is connected to the bottom segment by a connecting segment 40, which is formed in an arrowhead shape with a gradual change in the radial direction R. The connecting segments 40 here have an angle W1 relative to each other. In the radial direction R, the lubrication groove 32 is configured to end through an opening 36.

[0049] As from Figure 4 As can be seen, the opening 36 here has a smaller extension in the direction of the longitudinal axis L than the bottom section 38 of the lubrication groove 32. This tapering design of the lubrication groove 32 in the radial direction R prevents or at least reduces uncontrolled leakage of lubricant from the lubrication groove 32. Figure 4 In this context, adjacent lubrication grooves 32 have a distance X1 between them relative to each other in the direction of the longitudinal axis L.

[0050] exist Figure 5 The image shows an external view of the mating section 30. (See image from...) Figure 5 As can be seen, especially when viewed in the longitudinal direction L, the bearing surface 34 extends between two lubrication grooves 32. The lubrication grooves 32 here have a bottom section 38. Figure 5 In the illustrated case, the extensions of the bearing surfaces 34 between the two lubrication grooves 32 are helical, because the lubrication grooves 32 themselves are designed as lubrication spirals 32. Multiple lubrication spirals 32 exist in the mating section 30, and these multiple lubrication spirals are similar to multi-start threads forming a configuration around the longitudinal direction L.

[0051] List of reference numerals

[0052] 1 fastening element

[0053] 10 fixation section

[0054] 20 intermediate section

[0055] 30 engagement section

[0056] 32 lubrication groove

[0057] 34 bearing surface

[0058] 36 opening

[0059] 38 bottom section

[0060] 40 connection section

[0061] 100 mounting portion

[0062] 110 accommodation

[0063] 200 fixation portion

[0064] L longitudinal axis

[0065] R radial direction

[0066] W1 opening angle

[0067] X1 distance of two adjacent lubrication grooves in the direction of the longitudinal axis

Claims

1. A fastening element (1), comprising a fixing section (10), an intermediate section (20) and a mating section (30), wherein the fastening element (1) extends along a longitudinal axis (L), wherein the fixing section (10) has a fixing structure, wherein the intermediate section (20) is arranged between the fixing section (10) and the mating section (30) in the direction of the longitudinal axis (L), wherein the mating section (30) is essentially rotationally symmetrical around the longitudinal axis (L), wherein the mating section (30) has an outer load-bearing surface (34), wherein the outer load-bearing surface (34) has a clearance fit, and wherein at least one lubricating groove (32) is present in the mating section (30), characterized in that the ratio of the smallest diameter of the lubricating groove (32) to the diameter of the outer load-bearing surface (34) being in the range from 0.80 to 0.

98.

2. The fastening element (1) according to claim 1, wherein the at least one lubricating groove (32) is designed such that the outer load-bearing surface (34) can be wetted by a lubricant by means of the lubricating groove (32) when the fastening element (1) is moved in the direction of the longitudinal axis (L).

3. The fastening element (1) according to any one of the preceding claims, wherein the at least one lubricating groove (32) is a lubricating spiral (32).

4. The fastening element (1) according to claim 1, wherein the lubricating groove (32) has a pitch in the direction of the longitudinal axis (L), wherein the pitch of the lubricating groove (32) is in the range from 0.03 to 0.4 relative to the diameter of the outer load-bearing surface (34).

5. The fastening element (1) according to claim 1, wherein the outer load-bearing surface (34) is constructed cylindrically around the longitudinal axis (L).

6. The fastening element (1) according to claim 1, wherein the lubricating groove (32) has a cross section with an opening (36) pointing in the radial direction (R) and a bottom section (38).

7. The fastening element (1) according to claim 6, wherein the opening (36) has a smaller extension than the bottom section (38).

8. The fastening element (1) according to claim 1, wherein the ratio of the smallest diameter of the lubricating groove (32) to the diameter of the outer load-bearing surface (34) is in the range from 0.85 to 0.

95.

9. The fastening element (1) according to claim 1, wherein the load-bearing surface share of the mating section (30) is in the range from 0.3 to 0.

8.

10. A mounting system, comprising a mounting part (100) and a fastening element (1) according to any one of the preceding claims, wherein the mounting part (100) has a receptacle (110), wherein the fastening element (1) has a mating section (30), wherein the mating section (30) extends at least partially into the receptacle (110) or is designed for at least partial extension into the receptacle (110), wherein the accommodation (110) and the mating section (30) have a clearance fit relative to one another.

11. The mounting system according to claim 10, wherein the mating section (30) of the fastening element (1) is freely movable relative to the accommodation (110) in the direction of the longitudinal axis (L) in the mounted state.

12. The mounting system according to claim 10 or 11, wherein the mating section (30) has an outer load-bearing surface (34), wherein at least one lubricating groove (32) is present in the mating section (30), wherein the lubricating groove (32) is designed such that, upon movement of the fastening element (1) in the direction of the longitudinal axis (L), the outer load-bearing surface (34) and / or a portion of the accommodation (110) of the mounting part (100) which is in contact with and / or can come into contact with the mating section (30) can be wetted by a lubricant via the lubricating groove (32).

13. The mounting system according to claim 10, wherein the mounting part (100) is part of a brake caliper.

14. A production method for a fastening element (1) according to any one of claims 1 to 9, wherein the fastening element has a mating section (30) which has a lubricating groove (32) and an outer load-bearing surface (34), the method comprising the following steps: - providing a blank, - cold-forming the blank.

15. The production method for a fastening element (1) according to claim 14, wherein the outer load-bearing surface (34) of the mating section (30) is rolled.

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