METHOD FOR PRODUCING TEETH, TOOL AND MACHINE COMPONENT

Abstract

A method for producing a tooth geometry includes selecting a root-side starting contour configured as an ellipse segment and a head-side partial contour of a tooth; selecting an adaptation region for at least a part of the root-side starting contour; determining for the adaptation region a correction specification determined using a correction function configured as an at least third-order polynomial having at least one adjustable function parameter comprising adjustable coefficients; modifying the root-side starting contour using the correction specification to form a root-side final contour, and producing the tooth geometry by chip-removing machining based on the head-side partial contour and the root-side final contour. Also disclosed are a computer program product for carrying out the method, a tool for manufacturing the tooth geometry based on the method, and a machine component having the tooth geometry.

Claims

1.-15. (canceled)

16. A method for producing a serration, comprising: a) selecting a root-side starting contour configured as an ellipse segment and a head-side partial contour of a tooth; b) selecting an adaptation region for at least a part of the root-side starting contour; c) determining for the adaptation region a correction specification determined using a correction function configured as an at least third-order polynomial having at least one adjustable function parameter comprising adjustable coefficients; d) modifying the root-side starting contour using the correction specification to form a root-side final contour, and e) producing the tooth geometry by chip-removing machining based on the head-side partial contour and the root-side final contour.

17. The method of claim 16, wherein the head-side partial contour is configured as an involute.

18. The method of claim 16, wherein the correction function has a tooth space midpoint as a start point or as an end point.

19. The method of claim 16, wherein the correction function has a transition point between the root-side starting contour and the head-side partial contour.

20. The method of claim 16, wherein at least step c) is carried out repeatedly while modifying the at least one adjustable function parameter.

21. The method of claim 16, wherein step c) is carried out until a predeterminable target parameter is reached.

22. The method of claim 16, wherein at least step c) is carried out using a boundary element method calculation.

23. The method of claim 16, wherein the root-side starting contour (20) is configured at least in segments as an approximation of a basic serration representing a serration of an existing machine component.

24. The method of claim 16, wherein the correction function is adjusted by at least one of an algorithm, a function, a table, and a user input.

25. A computer program product embodies on a non-transitory computer-readable medium and comprising executable program instructions storable in a memory of a developer tool, wherein the program instructions when read from the memory and executed by a processor of the developer tool, cause the developer tool to output geometrical data of a root-side starting contour of a tooth geometry configured as an ellipse segment and a head-side partial contour of a tooth; select an adaptation region for at least a part of the root-side starting contour; determine for the adaptation region a correction specification determined using a correction function configured as an at least third-order polynomial having at least one adjustable function parameter comprising adjustable coefficients; modify the root-side starting contour using the correction specification to form a root-side final contour, and produce the tooth geometry by chip-removing machining based on the head-side partial contour and the root-side final contour.

26. A tool for processing a serration blank, comprising a blade constructed for chip-removing machining of a metallic material and having a shape that corresponds to at least a part of a root-side partial contour or a root-side final contour to be produced with the method according to claim 16.

27. A machine component comprising at least one serration having a plurality of teeth, wherein at least one of the teeth has a root-side partial contour that transitions discontinuously into a head-side partial contour, wherein the root-side partial contour corresponds in at least one segment to a superposition of an ellipse segment with an at least third-order polynomial curve.

28. The machine component of claim 27, wherein the head-side partial contour is configured as an involute.

Description

[0022] The invention will be described below with the aid of individual embodiments. The features of the individual embodiments may be combined with one another in this case. The figures are to be interpreted as mutually complimentary insofar as identical references in the figures also have the same technical meanings. In detail:

[0023] FIG. 1 shows a schematic detail view of a first embodiment of the claimed method and of a claimed machine component;

[0024] FIG. 2 shows a flowchart of a second embodiment of the claimed method;

[0025] FIG. 3 shows a schematic view of one embodiment of the claimed tool;

[0026] FIG. 4-7 show a schematic view of a plurality of embodiments of claimed machine components;

[0027] FIG. 8 shows a schematic structure of one embodiment of the claimed gearing.

[0028] FIG. 1 schematically shows a detail view of a claimed method 100 by which a serration 10 is produced on a machine component 60. FIG. 1 is represented as a normal section. The method 100 is represented by way of example with reference to a tooth 12 which belongs to the serration 10 to be produced. The method 100 is based on a basic serration 44, which is a serration of an already existing machine component which is improved by means of the method 100. The basic serration 44 is approximated in a first step 110 by a root-side starting contour 20, which is configured as an ellipse segment 21. The approximation 45 by the ellipse segment 21 represents a simple but sufficiently exact foundation for the purposes of the method 100. The root-side starting contour 20 extends between a tooth space midpoint 28 and merges at a transition point 29 into a head-side partial contour 22, the transition point 29 substantially being configured as a saddle point and thus allowing a continuous transition between the head-side partial contour 22 and the root-side starting contour 20. An adjacent tooth 14 follows on with its tooth rear side 16 from the tooth space midpoint 28 in one direction. The head-side partial contour 22 of the tooth 12 is configured as an involute 26. With the presence of the head-side partial contour 22 and the root-side starting contour 20, the first step 110 is completed.

[0029] In a second step 120, an adaptation region 38 in which the root-side starting contour 20 is to be modified, i.e. to be optimized, is selected. The adaptation region 38 extends between the tooth space midpoint 28 and the transition point 29 to the head-side partial contour 22. The adaptation region 38 is therefore delimited by a start point 32 and an end point 34, the position of which is adjustable, i.e. selectable, in the second step 120 by means of a user specification or an algorithm, for example a knowledge-based engineering algorithm.

[0030] Between the start point 32 and the end point 34, there is an extent axis 31 and perpendicularly thereto a value axis 33, onto which a correction function 30 that is to be set up for a third step 130 of the method 100 is defined. The correction function 30 is configured as a graph 37 of a polynomial 40, i.e. as a polynomial function. By a multiplicity of function values 36 of the correction function 30, a correction specification 35 that is to be applied to the root-side starting contour 20 is defined in the third step 130. Since the correction function 30 is substantially a polynomial 40, it may be adjusted by a multiplicity of function parameters 39. In the case of a polynomial 40 as in FIG. 1, these function parameters 39 are coefficients 42. The correction function 30 has zero as the function value 36 at the start point 32 and at the end point 34. Consequently, a root-side partial contour 24 to be determined by means of the method 100 remains at the transition point 29 and at the tooth space midpoint 28. In this way, discontinuities at these locations are prevented.

[0031] In a fourth step 140, the correction specification 35 is applied to the root-side starting contour 20. For this purpose, the root-side starting contour 20 is considered as a function in the coordinate system of the extent axis 31 and the value axis 33 and is superimposed with the correction specification 35. For this purpose, the function values 36 of the correction specification 35 and corresponding points 23 of the root-side starting contour 20 are added along the value axis 33. The root-side partial contour 24 is formed by this superposition. Target parameters 48 are taken into account during the formation of the root-side partial contour 24. One of the target parameters 48 according to FIG. 1 is a continuous transition between the root-side partial contour 24 and the head-side partial contour 22. A further target parameter 48 according to FIG. 1 consists in a predeterminable tooth root load capacity 47. The tooth root load capacity 47 on the root-side partial contour 24 determined may, for example, be determined by means of a boundary element method calculation 49. A boundary element method calculation 49 only takes into account contour elements 43 which lie directly on the root-side partial contour 24, i.e. on its surface.

[0032] The third step 130 is carried out repeatedly, while modifying the correction specification 35, until the target parameters 48 are fulfilled. Fulfillment or lack of a target parameter 48 may be determined in a fifth step 150. During repeated conduct of the third step 130, the function parameters 39 of the correction function 30 are varied, i.e. the coefficients 42 of the polynomial 40 are 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 steps 130, 140 thus run through a feedback loop, which is to be considered as a sixth step 160, until the root-side partial contour 24 or root-side final contour 24 is ascertained as the result 200 of the method 100. The root-side partial contour 24 determined in this way and the head-side partial contour 22 belong to geometrical data 46 of a tooth 12 of a serration 10. The geometrical data 46 may be used in order to produce a tool 50 (not depicted in detail) which is configured for machining manufacture of the serration 10.

[0033] FIG. 2 represents a flowchart of a second embodiment of the claimed method 100. The method 100 starts from a first step 110, in which a root-side starting contour 20 for a tooth 12 of a serration 10 to be produced is selected. In the first step 110, a head-side partial contour 22 of the tooth 12 is also selected. The root-side starting contour 20 is to be refined by the method 100 to form a root-side partial contour 24. In a subsequent second step 120, an adaptation region 38 for the root-side starting contour 20 is selected and established. The selection in the second step 120 is carried out by means of a user specification 41 and/or an algorithm 51, using a computer program product 80 in which the method 100 is carried out. The computer program product 80 is in this case executed in a developer tool 90. The adaptation region 38 defines the segment in which the root-side starting contour 20 is to be refined to form the root-side partial contour 24. The adaptation region 38 is delimited by a start point 32 and an end point 34, between which a correction function 30 is to be placed. The positions of the start point 32 and of the end point 34 are defined by the selection of the adaptation region 38. An extent axis 31 and a value axis 33, on which a third step 130 is based, are likewise defined by the adaptation region 38.

[0034] In the subsequent third step 130, a correction specification 35 is determined by means of a correction function 30. The correction function 35 has a graph 37 between the start point 32 defined in the second step 120 and the end point 34. The correction function 35 generates a multiplicity of function values 36 in the adaptation region 38. The function values 36 are superimposed in a fourth step 140 with corresponding points 23 on the root-side starting contour 20. For this purpose, the points 23 on the root-side starting contour 20 are considered as function values along the extent axis 31 and the value axis 33 of the correction function 30 and the function values 36 of the correction function 30 are added thereto. A root-side partial contour 24 which lies next to the head-side partial contour 22, i.e. merges into the latter, is thereby generated. In the fourth step 140, a check is carried out as to whether a target parameter 48 is reached by the refinement of the root-side starting contour 20 to form the root-side partial contour 24. The target parameter 48 is in this case an increased tooth root load capacity 47.

[0035] This is followed by a fifth step 150, which is configured as a procedural branch. If the achieved tooth root load capacity 47 is not reached with the root-side partial contour 24 determined, a sixth step 160, which is configured as a feedback loop, is carried out. In this way, the third and fourth steps 130, 140 are performed again. When performing the first step 130 again, at least one function parameter 39 of the correction function 30 is varied. The variation is in this case carried out by means of a user specification 41 or an algorithm 51, which is executed in a computer program product 80. If it is found in the fifth step 150 that the achieved tooth root load capacity 47 satisfies the target parameter 48, i.e. it reaches or exceeds the latter, a result output 200 follows. In the latter, the root-side partial contour 24 determined is output as the result 200 of the method 100.

[0036] FIG. 3 schematically shows a tool 50, which is configured as a cutting wheel. The cutting wheel 52 is configured to be rotatable about a rotation axis 15 and radially outwardly has a blade 55 which is configured for machining processing of a metallic material. In relation to a tool plane 56 lying in the plane of the drawing, the blade 55 is configured to correspond in shape at least on one side to a root-side partial contour 24. A processing contour 53 is correspondingly defined by the blade 55. The tool 50 is suitable for producing a corresponding serration 10, which comprises a corresponding tooth 12, with the processing contour 53, i.e. the blade 55, from a serration blank 58.

[0037] FIG. 4 to FIG. 7 represent various machine components 60, which are respectively equipped with a serration 10 that has a tooth 12, the shape of which is established according to by means of a claimed method 100. One of the corresponding machine components 60 is an externally serrated cogwheel 62, as shown in FIG. 4, a further corresponding machine component 60 is a bevel wheel 64 according to FIG. 5. Furthermore, FIG. 6 shows an internally serrated ring wheel 66 and FIG. 7 shows a toothed rack 68. An improved tooth root load capacity 47 is achieved by the improved serrations 10 in these machine components 60 according to FIG. 4 to FIG. 7. Furthermore, FIG. 8 depicts a gearing 70 that has an input shaft 72 via which a torque 75 is fed to the gearing 70 with a particular rotational speed 77. The gearing 70 also has an output shaft 74, via which a torque 75 is also delivered with a particular rotational speed 77. By the gearing 70, the torque 75 and the rotational speed 77 are modified from the input shaft 72 to the output shaft 74. The gearing 70 has at least one externally serrated cogwheel 62, a bevel wheel 64, an internally serrated ring wheel 66 and/or a toothed rack 68, which are produced according to a claimed method 100.