Patent ID: 12214433

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG.1schematically shows a detail view of a claimed method100by which a serration10is produced on a machine component60.FIG.1is represented as a normal section. The method100is represented by way of example with reference to a tooth12which belongs to the serration10to be produced. The method100is based on a basic serration44, which is a serration of an already existing machine component which is improved by means of the method100. The basic serration44is approximated in a first step110by a root-side starting contour20, which is configured as an ellipse segment21. The approximation45by the ellipse segment21represents a simple but sufficiently exact foundation for the purposes of the method100. The root-side starting contour20extends between a tooth space midpoint28and merges at a transition point29into a head-side partial contour22, the transition point29substantially being configured as a saddle point and thus allowing a continuous transition between the head-side partial contour22and the root-side starting contour20. An adjacent tooth14follows on with its tooth rear side16from the tooth space midpoint28in one direction. The head-side partial contour22of the tooth12is configured as an involute26. With the presence of the head-side partial contour22and the root-side starting contour20, the first step110is completed.

In a second step120, an adaptation region38in which the root-side starting contour20is to be modified, i.e. to be optimized, is selected. The adaptation region38extends between the tooth space midpoint28and the transition point29to the head-side partial contour22. The adaptation region38is therefore delimited by a start point32and an end point34, the position of which is adjustable, i.e. selectable, in the second step120by means of a user specification or an algorithm, for example a knowledge-based engineering algorithm.

Between the start point32and the end point34, there is an extent axis31and perpendicularly thereto a value axis33, onto which a correction function30that is to be set up for a third step130of the method100is defined. The correction function30is configured as a graph37of a polynomial40, i.e. as a polynomial function. By a multiplicity of function values36of the correction function30, a correction specification35that is to be applied to the root-side starting contour20is defined in the third step130. Since the correction function30is substantially a polynomial40, it may be adjusted by a multiplicity of function parameters39. In the case of a polynomial40as inFIG.1, these function parameters39are coefficients42. The correction function30has zero as the function value36at the start point32and at the end point34. Consequently, a root-side partial contour24to be determined by means of the method100remains at the transition point29and at the tooth space midpoint28. In this way, discontinuities at these locations are prevented.

In a fourth step140, the correction specification35is applied to the root-side starting contour20. For this purpose, the root-side starting contour20is considered as a function in the coordinate system of the extent axis31and the value axis33and is superimposed with the correction specification35. For this purpose, the function values36of the correction specification35and corresponding points23of the root-side starting contour20are added along the value axis33. The root-side partial contour24is formed by this superposition. Target parameters48are taken into account during the formation of the root-side partial contour24. One of the target parameters48according toFIG.1is a continuous transition between the root-side partial contour24and the head-side partial contour22. A further target parameter48according toFIG.1consists in a predeterminable tooth root load capacity47. The tooth root load capacity47on the root-side partial contour24determined may, for example, be determined by means of a boundary element method calculation49. A boundary element method calculation49only takes into account contour elements43which lie directly on the root-side partial contour24, i.e. on its surface.

The third step130is carried out repeatedly, while modifying the correction specification35, until the target parameters48are fulfilled. Fulfillment or lack of a target parameter48may be determined in a fifth step150. During repeated conduct of the third step130, the function parameters39of the correction function30are varied, i.e. the coefficients42of the polynomial40are modified. This modification or variation is carried out systematically by means of a user specification, an algorithm, a value table, an auxiliary function and/or artificial intelligence. The third and fourth steps130,140thus run through a feedback loop, which is to be considered as a sixth step160, until the root-side partial contour24or root-side final contour24is ascertained as the result200of the method100. The root-side partial contour24determined in this way and the head-side partial contour22belong to geometrical data46of a tooth12of a serration10. The geometrical data46may be used in order to produce a tool50(not depicted in detail) which is configured for machining manufacture of the serration10.

FIG.2represents a flowchart of a second embodiment of the claimed method100. The method100starts from a first step110, in which a root-side starting contour20for a tooth12of a serration10to be produced is selected. In the first step110, a head-side partial contour22of the tooth12is also selected. The root-side starting contour20is to be refined by the method100to form a root-side partial contour24. In a subsequent second step120, an adaptation region38for the root-side starting contour20is selected and established. The selection in the second step120is carried out by means of a user specification41and/or an algorithm51, using a computer program product80in which the method100is carried out. The computer program product80is in this case executed in a developer tool90. The adaptation region38defines the segment in which the root-side starting contour20is to be refined to form the root-side partial contour24. The adaptation region38is delimited by a start point32and an end point34, between which a correction function30is to be placed. The positions of the start point32and of the end point34are defined by the selection of the adaptation region38. An extent axis31and a value axis33, on which a third step130is based, are likewise defined by the adaptation region38.

In the subsequent third step130, a correction specification35is determined by means of a correction function30. The correction function30has a graph37between the start point32defined in the second step120and the end point34. The correction function30generates a multiplicity of function values36in the adaptation region38. The function values36are superimposed in a fourth step140with corresponding points23on the root-side starting contour20. For this purpose, the points23on the root-side starting contour20are considered as function values along the extent axis31and the value axis33of the correction function30and the function values36of the correction function30are added thereto. A root-side partial contour24which lies next to the head-side partial contour22, i.e. merges into the latter, is thereby generated. In the fourth step140, a check is carried out as to whether a target parameter48is reached by the refinement of the root-side starting contour20to form the root-side partial contour24. The target parameter48is in this case an increased tooth root load capacity47.

This is followed by a fifth step150, which is configured as a procedural branch. If the achieved tooth root load capacity47is not reached with the root-side partial contour24determined, a sixth step160, which is configured as a feedback loop, is carried out. In this way, the third and fourth steps130,140are performed again. When performing the first step130again, at least one function parameter39of the correction function30is varied. The variation is in this case carried out by means of a user specification41or an algorithm51, which is executed in a computer program product80. If it is found in the fifth step150that the achieved tooth root load capacity47satisfies the target parameter48, i.e. it reaches or exceeds the latter, a result output200follows. In the latter, the root-side partial contour24determined is output as the result200of the method100.

FIG.3schematically shows a tool50, which is configured as a cutting wheel. The cutting wheel52is configured to be rotatable about a rotation axis15and radially outwardly has a blade55which is configured for machining processing of a metallic material. In relation to a tool plane56lying in the plane of the drawing, the blade55is configured to correspond in shape at least on one side to a root-side partial contour24. A processing contour53is correspondingly defined by the blade55. The tool50is suitable for producing a corresponding serration10, which comprises a corresponding tooth12, with the processing contour53, i.e. the blade55, from a serration blank58.

FIG.4toFIG.7represent various machine components60, which are respectively equipped with a serration10that has a tooth12, the shape of which is established according to by means of a claimed method100. One of the corresponding machine components60is an externally serrated cogwheel62, as shown inFIG.4, a further corresponding machine component60is a bevel wheel64according toFIG.5. Furthermore,FIG.6shows an internally serrated ring wheel66andFIG.7shows a toothed rack68. An improved tooth root load capacity47is achieved by the improved serrations10in these machine components60according toFIG.4toFIG.7. Furthermore,FIG.8depicts a gearing70that has an input shaft72via which a torque75is fed to the gearing70with a particular rotational speed77. The gearing70also has an output shaft74, via which a torque75is also delivered with a particular rotational speed77. By the gearing70, the torque75and the rotational speed77are modified from the input shaft72to the output shaft74. The gearing70has at least one externally serrated cogwheel62, a bevel wheel64, an internally serrated ring wheel66and/or a toothed rack68, which are produced according to a claimed method100.