HYDRODYNAMIC SLIDING BEARING

Abstract

The application relates to a hydrodynamic sliding bearing (1), comprising - an inner ring element (2); - an outer ring element (3) wherein the inner ring element (2) and the outer ring element (3) are rotatable relative to each other about an axis of rotation (4); wherein either the inner ring element (2) or the outer ring element (3) has a sliding surface (5) and the other element of the inner ring element (2) or outer ring element (3) has a counter surface (6) corresponding to the sliding surface (5), wherein the sliding surface (5) has a non-circular cross-section and is tapered in axial extent.

Description

[0001] The invention relates to a hydrodynamic plain bearing.

[0002] In the past, engineers have attempted to combine both a thrust and a radial bearing into a single bearing, using either a conical or spherical shape. An example of such a hydrodynamic bearing with radial, thrust, and moment load capacity is described in prior art document US4243274A.

[0003] The arrangement described in US4243274A has the disadvantage that at high axial loads, the shaft becomes concentric with the bearing, preventing the oil from forming a wedge shape. Therefore, hydrodynamic pressure cannot be generated, leading to contact between a sliding surface and a counter-surface, drastically increasing bearing wear. Only at low axial loads do the shaft and bearing remain eccentric, allowing the formation of a conventional wedge-shaped oil film, thus allowing hydrodynamic pressure to be generated.

[0004] The technical objective of the present invention was to provide an improved hydrodynamic bearing capable of supporting high radial loads and high axial loads. Until the invention, the technical misconception prevailed that a hydrodynamic bearing could not be designed for high radial loads or high axial loads.

[0005] The technical problem is solved by a hydrodynamic plain bearing according to the claims.

[0006] According to one embodiment of the invention, a hydrodynamic plain bearing is provided. The hydrodynamic plain bearing comprises: - an inner ring element; - an outer ring element, wherein the inner ring element and the outer ring element are rotatable relative to each other about a rotation axis; wherein either the inner ring element or the outer ring element has a sliding surface and the other element of the inner ring element or the outer ring element has a counter surface corresponding to the sliding surface, The sliding surface has a non-circular cross-section and is tapered in the axial direction. This means that the non-circular cross-section is tapered in the axial direction.

[0007] The above features have the surprising effect that the hydrodynamic plain bearing can transmit high radial loads and high axial loads. The hydrodynamic wedge can be maintained under various conditions. This leads to improved wear behavior. Furthermore, the efficiency of the hydrodynamic plain bearing can be increased at high axial loads because the hydrodynamic oil film pressure can be maintained at high axial loads.

[0008] The taper of the sliding surface can be continuous. In one embodiment, the sliding surface can be tapered in the shape of a cone segment. In another embodiment, the sliding surface can be tapered in the shape of a spherical segment. In another embodiment, the taper can also be in the form of discontinuous shapes or combined shapes.

[0009] A further definition for a sliding surface tapering in axial extent can be that the diametrical distance of the sliding surface at a first axial position is greater than the diametrical distance of the sliding surface at a second axial position.

[0010] The non-circular cross-section of the sliding surface can therefore be described as non-rotationally symmetric.

[0011] The non-circular cross-section has the advantage that, in combination with the tapering in axial extension, a sufficient lubricating wedge can be formed between the sliding surface and the counter surface even at high axial loads, so that sufficient lubrication of the hydrodynamic plain bearing can be achieved.

[0012] The counter surface can have a circular cross-section. This means that the counter surface can appear rotationally symmetrical.

[0013] Furthermore, it may be useful if the cross-section of the sliding surface comprises a first surface and a second surface, wherein the first surface has a varying first radial distance from the axis of rotation in its axial extent. That is, each of the surfaces may be tapered in its axial extent.

[0014] Furthermore, it can be provided that the first surface and the second surface are designed as solid circular arc segments when viewed in cross-section. A sliding surface of this configuration can offer the advantage of further improving the efficiency of the hydrodynamic plain bearing. The surfaces can each be circular, with the cross-section of the sliding surface being able to have a discontinuous circular shape or a segmented circular shape.

[0015] Furthermore, each of the surfaces can be provided with an offset or inclination relative to the axis of rotation when viewed in cross-section. A sliding surface of this configuration can offer the advantage of further improving the efficiency of the hydrodynamic plain bearing.

[0016] According to a further development, it is possible for the first surface and the second surface to be separated by a lubricant supply groove extending in the axial direction. Such a lubricant supply groove can offer the advantage that sufficient lubricant can be supplied to the sliding surface to form a hydrodynamic wedge.

[0017] The lubricant supply groove may be located near a position where the geometry of the rotary pistons naturally begins to increase the radial distance between the contacting surfaces, creating sufficient clearance for the lubricating fluid to flow sufficiently to lubricate the sliding surface and the mating surface at the high pressure positions.

[0018] In particular, the lubricant supply groove can be located, viewed in the direction of rotation, directly behind the point at which the highest pressure of the lubricating fluid occurs.

[0019] In one embodiment, it is possible that the sliding surface comprises the first surface and the second surface and that a first lubricant supply groove and a second lubricant supply groove are arranged between the first surface and the second surface.

[0020] In a further embodiment, it is possible for the sliding surface to comprise the first surface, the second surface, and a third surface. A first lubricant supply groove can be arranged between the first surface and the second surface. A second lubricant supply groove can be arranged between the second surface and the third surface. A third lubricant supply groove can be arranged between the third surface and the first surface. According to this pattern, the sliding surface can comprise a plurality of surfaces. An embodiment in which a plurality of lubricant supply grooves can be distributed in a regular circular pattern over the circumference of the sliding surface is also advantageous. Such a pattern contributes to increasing the efficiency of the hydrodynamic plain bearing.

[0021] According to an advantageous development, the lubricant supply groove can extend over the entire axial direction of the sliding surface. These features make it possible to increase the efficiency of the hydrodynamic plain bearing, since the hydrodynamic effect can be achieved over the entire axial extent of the sliding surface.

[0022] Furthermore, it can be useful to arrange a lubricant distribution groove above the lubricant supply groove, which extends only partially in the axial direction of the sliding surface. This offers the advantage of improving the supply of lubricant from the outside to the sliding surface.

[0023] It may also be provided that lubricant supply bores are formed that open into the lubricant supply groove. In particular, the lubricant supply bores can open into the lubricant distribution groove.

[0024] Furthermore, the lubricant supply groove can be formed by a kink or a step between the first surface and the second surface, with one edge of the lubricant supply groove having a varying second radial distance from the axis of rotation in the axial direction. A stepped design can be achieved by inclining the first surface and the second surface or offsetting them radially from one another. The sliding surface with such a stepped design offers advantages when the hydrodynamic plain bearing has only one intended direction of rotation during use.

[0025] As an alternative to the stepped design, it is possible for the first surface and the second surface to be arranged symmetrically relative to each other with respect to the lubricant supply groove. Such a configuration offers the advantage that, with such a symmetrical shape, the sliding surface does not have to exhibit a specific direction of rotation during use.

[0026] Furthermore, the sliding surface can be provided with a circumferentially closed surface, or with a circumferentially closed surface penetrated by lubricant supply holes. Such a shape offers surprising efficiency advantages.

[0027] According to a further development, it is possible for the sliding surface to be segmented in the circumferential direction and to comprise a first segment and a second segment, wherein the first segment and the second segment are seamlessly connected to one another. In particular, it is possible for the transition between the first segment and the second segment to be located at a circumferential distance from the lubricant supply groove.

[0028] An embodiment according to which it can be provided that the counter surface has a circular cross-section which is tapered in the axial direction is also advantageous.

[0029] According to a particular embodiment, it is possible for the counter surface to be tapered in the axial direction in the shape of a cone segment.

[0030] According to an alternative embodiment, it is possible for the counter surface to be tapered in the axial direction in the shape of a spherical segment. This offers the advantage that such a configuration allows for an inclination of the inner ring element relative to the outer ring element without edge loading.

[0031] According to a particular embodiment, it is possible for the sliding surface to be tapered in the axial direction in the shape of a cone segment.

[0032] According to an alternative embodiment, it is possible for the counter surface to be tapered in the axial direction in the shape of a spherical segment.

[0033] In an alternative embodiment, it is possible for the counter surface to be tapered in the axial direction in the shape of a spherical segment in combination with the shape of a conical segment.

[0034] In an alternative embodiment, it is possible for the counter surface to be tapered in the axial direction in the form of any hyperbolic or other structure or in combined structural shapes.

[0035] According to an advantageous further development, it can be provided that the sliding surface is arranged on the inner ring element and has a convex shape in the axial direction.

[0036] In an alternative embodiment, it can be provided that the sliding surface is arranged on the inner ring element and has a concave shape in the axial direction.

[0037] In an alternative embodiment, it can be provided that the sliding surface is arranged on the outer ring element and has a convex shape in the axial direction.

[0038] In an alternative embodiment, it can be provided that the sliding surface is arranged on the outer ring element and has a concave shape in the axial direction.

[0039] Furthermore, it may be useful if the non-circular cross-section of the sliding surface has an elliptical shape, or the non-circular cross-section of the sliding surface has a staggered bisected shape, or the non-circular cross-section of the sliding surface has a pressure dam shape, or the non-circular cross-section of the sliding surface has a multi-surface shape, such as a tri-surface shape, a quadri-surface shape, etc., or the non-circular cross-section of the sliding surface has a multi-pocket shape.

[0040] According to a particular embodiment, it is possible for the sliding surface to have a first radius and the counter surface to have a second radius in a specific longitudinal section plane, the first radius and the second radius being offset from one another by a distance, the distance having a value in the range from 0.00005 to 0.002 multiplied by the first radius. In particular, it is advantageous if the distance has a value in the range from 0.0009 to 0.0011 multiplied by the first radius. The distance offers the advantage that a lubricating film can build up in the distance which, viewed in the specific longitudinal section, has a constant film thickness. This increases the efficiency of the hydrodynamic plain bearing. At the same time, wear on the hydrodynamic plain bearing can be reduced.The special longitudinal section plane may be located at a minimum distance point located at an intersection point of a surface with a virtual base circle.

[0041] The special cutting plane can be arranged at a circumferential distance of (360° divided by the number of faces multiplied by the inclination) from the lubricant supply groove. This means that the inclination defines the shape of the faces.

[0042] If the inclination is 0.5, the surfaces are symmetrical, meaning the first surface and the second surface intersect seamlessly. This type of hydrodynamic plain bearing can be used when the hydrodynamic plain bearing is intended to allow rotation in both directions. The intersection point between the first surface and the second surface, which defines the lubricant supply groove, can be designed in the form of a kink in the surface.

[0043] If the inclination is less than or greater than 0.5, the surfaces are asymmetric, meaning the lubricant supply groove where the first and second surfaces intersect has a step. It is particularly advantageous if the inclination is in the range of 0.15 to 0.18. Such arrangements offer the advantage that performance can be increased when the hydrodynamic plain bearing is rotated in one main direction. This means that hydrodynamic plain bearings with such an arrangement can be used in applications where only one direction of rotation occurs.

[0044] According to a further development, it is possible for a three-surface bearing to have the special cutting plane arranged at a circumferential distance of 10° to 30° from the lubricant supply groove. It is particularly advantageous if the special cutting plane is arranged at a circumferential distance of 18° to 22° from the lubricant supply groove.

[0045] Viewed in the direction of rotation, the special cutting plane of a three-surface bearing can be arranged at a circumferential distance of 10° to 30° behind the lubricant supply groove. This arrangement can be applied to a hydrodynamic plain bearing with a primary direction of rotation.

[0046] According to one embodiment of the invention, a hydrodynamic plain bearing is provided. The hydrodynamic plain bearing comprises: - an inner ring element; - an outer ring element, wherein the inner ring element and the outer ring element are rotatable relative to each other about a rotation axis; wherein either the inner ring element or the outer ring element has a sliding surface and the other element of the inner ring element or the outer ring element has a counter surface corresponding to the sliding surface, wherein the sliding surface is tapered in the axial direction, wherein the sliding surface has at least two surfaces extending in the axial direction on the tapered sliding surface.

[0047] According to one embodiment of the invention, a hydrodynamic plain bearing is provided. The hydrodynamic plain bearing comprises: - an inner ring element; - an outer ring element, wherein the inner ring element and the outer ring element are rotatable relative to each other about a rotation axis; wherein either the inner ring element or the outer ring element has a sliding surface and the other element of the inner ring element or the outer ring element has a counter surface corresponding to the sliding surface, wherein the sliding surface has a first non-circular profile and a second non-circular profile which are axially offset from one another, the first non-circular profile and the second non-circular profile having different dimensions, the sliding surface being extruded along guideways between the first non-circular profile and a second non-circular profile.

[0048] In addition, it may be useful if the first non-circular profile and the second non-circular profile of the sliding surface have an elliptical shape, or the first non-circular profile and the second non-circular profile of the sliding surface have a staggered bisected shape, or the first non-circular profile and the second non-circular profile of the sliding surface have a pressure dam shape, or the first non-circular profile and the second non-circular profile of the sliding surface have a multi-surface shape, such as a tri-surface shape, a quadriface shape, etc., or the first non-circular profile and the second non-circular profile of the sliding surface have a multi-pocket shape.

[0049] The hydrodynamic plain bearing described in this document can be used in rotating assemblies that must accommodate high radial loads as well as high axial loads. One such application could be the support of helical gears. Such helical gears can be used particularly in planetary gearboxes.

[0050] The sliding surface of the hydrodynamic plain bearing can be provided with a friction protection layer. The friction protection layer can be applied to a carrier layer.

[0051] In particular, the friction protection layer can consist of a plain bearing material, at least on the surface of the friction protection layer, which serves as the sliding surface. The friction protection layer can, for example, consist of a material selected from a group comprising aluminum-based alloys such as AlSn20Cu, AlZn4Si3, silver-based alloys or copper-based alloys, optionally with bismuth, and bismuth-based alloys. The hardness of such a plain bearing material can range between 20 HV (0.001) and 40 HV (0.001) for tin-based Babbitts. For plain bearing materials that include aluminum, the hardness can be between 40 HV (0.001) and 70 HV (0.001).

[0052] The friction protection layer can also be formed by a friction protection varnish, in which case the friction protection layer can have a hardness between 25 HV (0.001) and 60 HV (0.001).

[0053] The anti-friction coatings used can be, for example, polytetrafluoroethylene, fluorine-containing resins, such as perfluoroalkoxy copolymers, polyfluoroalkoxy-polytetrafluoroethylene copolymers, ethylene-tetrafluoroethylene, polychlorotrifluoroethylene, fluorinated ethylene-propylene copolymers, polyvinyl fluoride, polyvinylidene fluoride, alternating copolymers, random copolymers, such as perfluoroethylene-propylene, polyesterimides, bismaleimides, polyimide resins, such as carboranimides, aromatic polyimide resins, hydrogen-free polyimide resins, polytriazo-pyromellitimides, polyamideimides, in particular aromatic ones, polyaryletherimides, optionally modified by isocyanates, polyetherimides, optionally modified by isocyanates, epoxy resins, epoxy resin esters, phenolic resins, polyamide 6, polyamide 66, polyoxymethylene, silicones, polyarylethers, Polyaryl ketones, polyaryl ether ketones, polyaryl ether ether ketones, polyether ether ketones, polyether ketones, polyvinylidene difluoride, polyethylene sulfides,Allylene sulfide, polytriazo-pyromellithimides, polyesterimides, polyarylsulfides, polyvinylene sulfides, polyphenylene sulfides, polysulfones, polyethersulfones, polyarylsulfones, polyaryloxides, polyarylsulfides and their copolymers.

[0054] Preferred is a friction protection varnish which, in the dry state, contains 40 wt.% to 45 wt.% MoS2, 20 wt.% to 25 wt.% graphite and 30 wt.% to 40 wt.% polyamideimide, wherein the friction protection varnish may optionally also comprise hard particles, such as oxides, nitrides or carbides, in a total proportion of not more than 20 wt.%, which replace part of the solid lubricants.

[0055] The carrier layer can, for example, consist of steel or a copper-based alloy, in particular with zinc, for example CuZn31Si, CuSnZn, an AlZn or a CuAl alloy.

[0056] In one embodiment, the sliding surface and the counter surface can be designed to have good dry-running properties. In this case, no additional oil pump is required for starting or decelerating the rotation.

[0057] In an alternative embodiment, the bearings can be raised hydrostatically and switched to operation with partially or fully hydrodynamic lubrication by the targeted control of a lubricant pump.

[0058] In one embodiment, the sliding surface can be formed on a bushing, wherein the bushing is inserted between two parts that must be rotated relative to each other. The counter surface can be formed on one of the two parts that must be rotated relative to each other. In this case, the bushing can be attached to a shaft or pin, wherein the sliding surface is formed on the outer surface of the bushing. The bushing can also be attached to a bore, wherein the sliding surface is formed on the inner surface of the bushing.

[0059] In an alternative embodiment, the sliding surface may be formed directly on one of the two parts that need to be rotated relative to each other and the counter surface may be formed on the other of the two parts that need to be rotated relative to each other.

[0060] The sliding surface can be formed on the rotating ring element. The sliding surface can also be formed on the stationary ring element.

[0061] The sliding surface can be made of a low-friction material. It is also possible for the counter surface to be made of a low-friction material.

[0062] An oil can be used as a lubricant for the hydrodynamic plain bearing.

[0063] For a better understanding of the invention, it is explained in more detail using the following figures.

[0064] These show in a very simplified schematic representation: Fig. 1 shows a longitudinal section of a first embodiment of an outer ring element and an inner ring element in the assembled state; Fig. 2 shows a cross section of the first embodiment of the outer ring element and the inner ring element in the assembled state; Fig. 3 is a perspective view of the first embodiment of the outer ring element; Fig. 4 is a perspective view of the first embodiment of the inner ring element; Fig. 5 is a perspective view of a second embodiment of the outer ring element; Fig. 6 shows a longitudinal section of a third embodiment of the outer ring element and the inner ring element in the assembled state; Fig. 7 is a perspective view of the third embodiment of the outer ring member; Fig. 8 shows a longitudinal section of a fourth embodiment of the outer ring element and the inner ring element in the assembled state; Fig. 9 is a perspective view of the fourth embodiment of the inner ring element; Fig. 10 is a longitudinal section of a fifth embodiment of the outer ring element and the inner ring element in the assembled state; Fig. 11 is a perspective view of the fifth embodiment of the inner ring element; Fig. 12 is a perspective view of the geometric design elements of the fifth embodiment of the inner ring element; Fig. 13 a perspective view of the geometry in a special longitudinal section of the fifth embodiment of the inner ring element.

[0065] By way of introduction, it should be noted that in the variously described embodiments, identical parts are provided with identical reference symbols or component designations. The disclosures contained throughout the description can be applied analogously to identical parts with identical reference symbols or component designations. Furthermore, the positional information chosen in the description, such as top, bottom, side, etc., refers to the directly described and illustrated figure, and these positional information must be applied analogously to the new position in the event of a change in position.

[0066] The Fig. 1 to 4 show a first embodiment of individual parts and the assembly of a hydrodynamic plain bearing 1. The following description refers to an overall view of the individual figures.

[0067] As from Fig. 1, the hydrodynamic plain bearing 1 comprises an inner ring element 2. The hydrodynamic plain bearing 1 also comprises an outer ring element 3. The inner ring element 2 and the outer ring element 3 can be rotatable relative to one another about a rotation axis 4.

[0068] In the first embodiment, the outer ring element 3, which in Fig. 3 is shown in detail, a sliding surface 5. The sliding surface 5 corresponds to a counter surface 6, which is arranged on the inner ring element 2, which in Fig. 4 is shown in detail.

[0069] In the first embodiment, the inner ring element 2 is rotationally symmetrical and has a first cylindrical portion 7 and a second cylindrical portion 8, with the counter surface 6 being arranged between the first cylindrical portion 7 and the second cylindrical portion 8. A diameter of the second cylindrical portion 8 can be larger than a diameter of the first cylindrical portion 7. In this embodiment, the counter surface 6 has a concave shape.

[0070] In the first embodiment, the sliding surface 5 of the outer ring element 3 has a convex shape. The sliding surface 5 of the outer ring element 3 may include a first surface 9, a second surface 10, and a third surface 11.

[0071] As from Fig. As can be seen in Figure 3, the first surface 9 has a varying first radial distance 12 from the axis of rotation in its axial extent. The first radial distance 12 can vary not only in its axial extent, but also in its circumferential extent.

[0072] In the first embodiment, a lubricant supply groove 13 is formed by a step between the first surface 9 and the second surface 10. In general, one of the lubricant supply grooves 13 can be arranged between the surfaces 9, 10, 11.

[0073] In the axial direction, an edge 14 of the lubricant supply groove 13 can have a varying second radial distance 15 from the axis of rotation 4.

[0074] It is also possible for a lubricant distribution groove 16 to be located above the lubricant supply groove 13. The lubricant distribution groove 16 may extend only partially in the axial extent of the sliding surface 5. Furthermore, it is possible for each lubricant supply roller 13 to be equipped with a lubricant distribution groove 16.

[0075] As shown, it is also possible for a lubricant supply bore 17 to open into the lubricant supply groove 13. This means that the lubricant supply bore 17 can open into the lubricant distribution groove 16.

[0076] Fig. 5 shows a second exemplary embodiment of the outer ring element 3 in a perspective view, wherein again the same reference numerals / component designations for the same parts as before in Fig. 3. To avoid unnecessary repetition, please refer to the detailed description in the previous Fig. 3 is mentioned or referred to.

[0077] As from Fig. As can be seen in Figure 5, it is possible for the sliding surface 5 to be segmented in the circumferential direction and to comprise a first segment 18 and a second segment 19. The first element 18 and the second element 19 can be seamlessly connected to one another. It is possible for the outer ring element 3 to consist of two half-shells. In this case, the first segment 18 and the second segment 19 each have the shape of a halved outer ring element 3. It is also possible for the sliding surface 5 to be segmented into further segments.

[0078] Fig. 6 and Fig. 7 show a third exemplary embodiment of the inner ring element 2 and the outer ring element 3, wherein again the same reference numerals / component designations for the same parts as before in Fig. 1 to 4. To avoid unnecessary repetition, please refer to the detailed description in the previous Fig. 1 to 4 are mentioned or referred to.

[0079] As can be seen from the Fig. 6 and Fig. As can be seen from Figure 7, the sliding surface 5 can be arranged on the outer ring element 3, and the counter surface 6 can be arranged on the inner ring element 2. The sliding surface 5 can have a concave shape. The counter surface 6 can have a convex shape.

[0080] The Fig. 8 and Fig. 9 show a fourth exemplary embodiment of the inner ring element 2 and the outer ring element 3, wherein again the same reference numerals / component designations for the same parts as before in the Fig. 1 to 4. To avoid unnecessary repetition, please refer to the detailed description in the previous Fig. 1 to 4 are mentioned or referred to.

[0081] As can be seen from the Fig. 8 and Fig. As can be seen in Figure 9, the sliding surface 5 can be arranged on the inner ring element 2, and the counter surface 6 can be arranged on the outer ring element 3. The sliding surface 5 can have a convex shape. The counter surface 6 can have a concave shape.

[0082] The Fig. 10 and Fig. 11 show a fifth exemplary embodiment of the inner ring element 2 and the outer ring element 3, wherein again the same reference numerals / component designations for the same parts as before in the Fig. 1 to 4. To avoid unnecessary repetition, please refer to the detailed description in the previous Fig. 1 to 4 are mentioned or referred to.

[0083] As can be seen from the Fig. 10 and Fig. As can be seen in Figure 11, the sliding surface 5 can be arranged on the inner ring element 2, and the counter surface 6 can be arranged on the outer ring element 3. The sliding surface 5 can have a concave shape. The counter surface 6 can have a convex shape.

[0084] Fig. 12 shows construction elements of the fifth exemplary embodiment of the inner ring element 2, wherein again the same reference numerals / component designations for the same parts as before in the Fig. 1 to 4. To avoid unnecessary repetition, please refer to the detailed description in the previous Fig. 1 to 4 are mentioned or referred to.

[0085] As from Fig. As can be seen in Figure 12, the sliding surface 5 can be defined by a first non-circular profile 20 and a second non-circular profile 21. The first non-circular profile 20 and the second non-circular profile 21 can be axially offset 22 from one another.

[0086] The first non-circular profile 20 and the second non-circular profile 21 have different dimensions. In particular, the second non-circular profile 21 can be a radial offset of the first non-circular profile 20. The first non-circular profile 20 and the second non-circular profile 21 can be implemented as an inclined trihedral geometry. The first non-circular profile 20 can be based on a first virtual base cycle 30. At a first minimum distance point 32, the first surface 9 can intersect with the first virtual base cycle 30. At a second minimum distance point 33, the second surface 10 can intersect with the first virtual base cycle 30. At a third minimum distance point 34, the third surface 11 can intersect with the first virtual base cycle 31.In the configuration of the fifth exemplary embodiment, the minimum distance points 32, 33, 34 may be the radially outermost points of the first non-circular profile 20.

[0087] The second non-circular profile 21 may be based on a second virtual base cycle 31.

[0088] The geometry of the sliding surface 5 can be defined by an extrusion of the first circular profile 20, which transitions into the second non-circular profile 21 along the guideways 23, 24, 25, 26, 27, 28. The first guideway 23, the second guideway 24, and the third guideway 25 can each be arranged on one of the edges 14 of the lubricant supply grooves 13.

[0089] The fourth guideway 26 can be arranged at the first minimum distance point 32. The fifth guideway 27 can be arranged at the second minimum distance point 33. The sixth guideway 28 can be arranged at the third minimum distance point 34. The fourth guideway 26, the fifth guideway 27, and the sixth guideway 28 can therefore define a first radius 29 or main radius of the surfaces of the sliding surface 5.

[0090] The geometry of the first non-circular profile 20 of the fifth exemplary embodiment of the inner ring element 2 has an inclination of 0.166.

[0091] Fig. 13 shows the fifth exemplary embodiment of the inner ring element 2, wherein again the same reference numerals / component designations for the same parts as before in the Fig. 1 to 4. To avoid unnecessary repetition, please refer to the detailed description in the previous Fig. 1 to 4. The Fig. 13 shown inner ring element 2 is constructed as in connection with Fig. 12 described.

[0092] In Fig. 13, the special longitudinal section plane 35 is defined such that it intersects with one of the minimum distance points 32, 33, 34. In this special longitudinal section plane 35, the first radius 29 or main radius of the sliding surface 5 is shown.

[0093] In Fig. Figure 13 also shows a cross-section of the outer ring element 3 in the special longitudinal section plane 35. As shown, the special longitudinal section plane 35 and the counter surface 6 have a second radius 36. The first radius 29 and the second radius 36 are spaced apart by a distance 37. This distance 37 determines the film thickness of the lubricant.

[0094] The embodiments show possible embodiments, whereby it should be noted at this point that the invention is not limited to the specifically illustrated embodiments thereof, but rather various combinations of the individual embodiments with each other are also possible and this variation possibility lies within the skill of the person skilled in the art in this technical field due to the knowledge of the technical effect of the present invention.

[0095] The scope of protection is determined by the claims. However, the description and drawings must be used to interpret the claims. Individual features or combinations of features from the various embodiments shown and described may represent independent inventive solutions. The problem underlying these independent inventive solutions can be derived from the description.

[0096] All references to value ranges in this description are to be understood as including any and all sub-ranges thereof; for example, the reference 1 to 10 is to be understood as including all sub-ranges related to the lower limit of 1 and the upper limit of 10, i.e., all sub-ranges begin with a lower limit of 1 or greater and end with an upper limit of 10 or less, for example 1 to 1.7, or 3.2 to 8.1, or 5.5 to 10.

[0097] For the sake of clarity, it should be noted that, to facilitate understanding of the structure, some elements are not shown to scale and / or are enlarged and / or reduced in size. For clarity, the distances between the surfaces in the figures are exaggerated. List of reference symbols 1 hydrodynamic plain bearing 2 inner ring element 3 Outer ring element 4 axis of rotation 5 Sliding surface 6 Counter surface 7 first cylindrical section 8 second cylindrical section 9 first area 10 second area 11 third area 12 first radial distance 13 Lubricant supply groove 14 Edge of the lubricant supply groove 15 second radial distance 16 Lubricant distribution groove 17 Lubricant supply hole 18 first segment 19 second segment 20 first non-circular profile 21 second non-circular profile 22 axial offset 23 first guideway 24 second guideway 25 third guideway 26 fourth guideway 27 fifth guideway 28 sixth guideway 29 first radius 30 first virtual base cycle 31 second virtual base cycle 32 first minimum distance point 33 second minimum distance point 34 third minimum distance point 35 special longitudinal section plane 36 second radius 37 distance QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 4243274A [0002, 0003]

Claims

[1] Hydrodynamic plain bearing (1), comprising: - an inner ring element (2); - an outer ring element (3), wherein the inner ring element (2) and the outer ring element (3) are rotatable relative to one another about an axis of rotation (4); wherein either the inner ring element (2) or the outer ring element (3) has a sliding surface (5) and the other element of the inner ring element (2) or outer ring element (3) has a counter surface (6) corresponding to the sliding surface (5), wherein the sliding surface (5) has a non-circular cross-section and is tapered in axial extent. [2] Hydrodynamic plain bearing (1) according to claim 1, characterized by that the cross-section of the sliding surface (5) comprises a first surface (9) and a second surface (10), wherein the first surface (9) has a varying first radial distance (12) from the axis of rotation (4) in its axial extent. [3] Hydrodynamic plain bearing (1) according to claim 2, characterized by that the first surface (9) and the second surface (10) are designed as fixed circular arc segments when viewed in cross section. [4] Hydrodynamic plain bearing (1) according to claim 2 or 3, characterized by that, viewed in cross-section, each of the surfaces (9, 10) has an offset or an inclination to the axis of rotation (4). [5] Hydrodynamic plain bearing (1) according to one of claims 2 to 4, characterized by that the first surface (9) and the second surface (10) are separated by a lubricant supply groove (13) extending in the axial direction. [6] Hydrodynamic plain bearing (1) according to claim 5, characterized by that a plurality of lubricant supply grooves (13) are distributed as a regular circular pattern over the circumference of the sliding surface (5). [7] Hydrodynamic plain bearing (1) according to claim 5 or 6, characterized bythat the lubricant supply groove (13) extends over the entire axial extent of the sliding surface (5). [8] Hydrodynamic plain bearing (1) according to one of claims 5 to 7, characterized by that the lubricant supply groove (13) is overlaid by a lubricant distribution groove (16), wherein the lubricant distribution groove (16) extends only partially in an axial extent of the sliding surface (5). [9] Hydrodynamic plain bearing (1) according to one of claims 5 to 8, characterized by that the lubricant supply groove (13) is formed by a kink or a step between the first surface (9) and the second surface (10), wherein an edge (14) of the lubricant supply groove (13) has a varying second radial distance (15) from the axis of rotation (4) in the axial direction. [10] Hydrodynamic plain bearing (1) according to one of claims 1 to 9, characterized bythat the sliding surface (5) is a circumferentially closed surface, or that the sliding surface (5) is a circumferentially closed surface which is penetrated by lubricant supply bores (17). [11] Hydrodynamic plain bearing (1) according to one of claims 1 to 9, characterized by that the sliding surface (5) is segmented in the circumferential direction and comprises a first segment (18) and a second segment (19), wherein the first segment (18) and the second segment (19) are seamlessly connected to one another. [12] Hydrodynamic plain bearing (1) according to one of the preceding claims, characterized by that the counter surface (6) has a circular cross-section and is tapered in the axial direction. [13] Hydrodynamic plain bearing (1) according to claim 12, characterized by that the counter surface (6) is tapered in the axial direction in the shape of a cone segment. [14] Hydrodynamic plain bearing (1) according to claim 12, characterized bythat the counter surface (6) is tapered in the axial direction in the form of a spherical segment. [15] Hydrodynamic plain bearing (1) according to one of the preceding claims, characterized by that the sliding surface (5) is conically tapered in the axial direction in the shape of a cone segment. [16] Hydrodynamic plain bearing (1) according to one of the preceding claims, characterized by that the sliding surface (5) is arranged on the inner ring element (2) and has a convex shape in the axial direction, or that the sliding surface (5) is arranged on the inner ring element (2) and has a concave shape in the axial direction. [17] Hydrodynamic plain bearing (1) according to one of the preceding claims, characterized by that the counter surface (5) is arranged on the outer ring element (3) and has a convex shape in the axial direction, or that the sliding surface (5) is applied to the outer ring element (3) and has a concave shape in the axial direction. [18] Hydrodynamic plain bearing (1) according to one of the preceding claims, characterized by that the non-circular cross-section of the sliding surface (5) has an elliptical shape, or the non-circular cross-section of the sliding surface (5) has a staggered halved shape, or the non-circular cross-section of the sliding surface (5) has a pressure dam shape, or the non-circular cross-section of the sliding surface (5) has a multi-surface shape, or the non-circular cross-section of the sliding surface (5) has a multi-pocket shape. [19] Hydrodynamic plain bearing (1) according to one of the preceding claims, characterized byin that in a special longitudinal section plane (35) the sliding surface (5) has a first radius (29) and the counter surface (6) has a second radius (36), wherein the first radius (29) and the second radius (36) are offset from one another by a distance (37), wherein the distance (37) has a size which is in the range from 0.00005 to 0.002 multiplied by the first radius (29). [20] Hydrodynamic plain bearing (1) according to claim 20, characterized by that the special longitudinal cutting plane (35) is arranged at a circumferential distance of 10° to 30° from the lubricant supply groove (13). [21] Hydrodynamic plain bearing (1), comprising: - an inner ring element (2); - an outer ring element (3), wherein the inner ring element (2) and the outer ring element (3) are rotatable relative to one another about an axis of rotation (4); wherein either the inner ring element (2) or the outer ring element (3) has a sliding surface (5) and the other element of the inner ring element (2) or outer ring element (3) has a counter-surface (6) corresponding to the sliding surface (5), wherein the sliding surface (5) has a first non-circular profile (20) and a second non-circular profile (21) which are axially offset (22) from one another, wherein the first non-circular profile (20) and the second non-circular profile (21) have different dimensions, wherein the sliding surface (5) is an extrusion of the first non-circular profile (20) which merges into the second non-circular profile (21) along guide tracks (23, 24, 25, 26, 27, 28). [22] Hydrodynamic plain bearing (1) according to claim 21, characterized bythat the first non-circular profile (20) and the second non-circular profile (21) of the sliding surface (5) have an elliptical shape, or the first non-circular profile (20) and the second non-circular profile (21) of the sliding surface (5) have an offset halved shape, or the first non-circular profile (20) and the second non-circular profile (21) of the sliding surface (5) have a pressure dam shape, or the first non-circular profile (20) and the second non-circular profile (21) of the sliding surface (5) have a multi-surface shape, or the first non-circular profile (20) and the second non-circular profile (21) of the sliding surface (5) have a multi-pocket shape.

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