Modified master gear

Abstract

A master gear for the rolling test of gear teeth, wherein the master gear (100) has a gear tooth (102) with a plurality of teeth (104), wherein the master gear (100) has at least two segments (110, 112, 114), wherein each of the segments (110, 112, 114) is assigned one tooth (104) or several teeth (104) of the plurality of teeth (104), and wherein the teeth (104) of one of the segments (110, 112, 114) have a geometry that differs from the geometry of the teeth (104) of another of the segments (110, 112, 114).

Description

[0001] The present invention relates to a master gear for the rolling test of gears, wherein the master gear has a gearing with a plurality of teeth. Furthermore, the invention relates to a method for the rolling test of gears.

[0002] The rolling test of gears, also known as the rolling test, is used for quality assurance. Typically, a master gear manufactured as perfectly as possible rolls with the gearing to be tested in such a way that each tooth or tooth flank of the gearing to be tested engages and rolls with each tooth of the master gear in question. Since the master gear in question, according to the state of the art, has teeth with identical geometries, with each individual tooth of the master gear corresponding as closely as possible to a specified target geometry, a large amount of redundant information or measurement data is generated during the aforementioned rolling test.

[0003] A disadvantage of rolling test using such a master gear is that this test cannot predict the subsequent rolling behavior of the gearing to be tested in combination with the actual mating gear assigned in the installed state. Therefore, all tolerance levels of the mating gear must be taken into account when determining the rolling test tolerances. Furthermore, the usual evaluation of the deviations determined during the rolling test does not provide any information about the direction of the geometric deviations on the tested gears.

[0004] Against this background, the present invention is based on the technical problem of specifying a master gear for the rolling test of gears and a method for the rolling test of gears, which enable a more practical testing of gears and, in particular, can obtain less redundant but, compared to the classic rolling test, more information on the rolling behavior of the gear to be tested.

[0005] The technical problem described above is solved by means of the independent claims. Further embodiments of the invention emerge from the dependent claims and the following description.

[0006] According to a first aspect, the invention relates to a master gear for the rolling test of gears, wherein the master gear has a gearing with a plurality of teeth. The master gear is characterized in that the master gear has at least two segments, wherein each of the segments is assigned one or more teeth of the plurality of teeth, and wherein the at least one tooth or teeth of one of the segments have a geometry that differs from the geometry of the at least one tooth or teeth of another of the segments.

[0007] The invention is based on the idea of ​​not designing the geometry of the teeth of the master gear uniformly, but rather, for example, providing different geometric modifications segment by segment, which, for example, reflect the extremes or limit positions of the possible tolerance positions of the respective mating gear to a gearing to be tested.

[0008] For example, certain segments of the master gear can simulate the worst-case scenario for certain toothing deviations of the mating gear, such as a flank angle deviation or a profile angle deviation. By evaluating the rotational errors resulting from rolling with these segments, conclusions can be drawn about the rolling behavior of the gearing under test when operating with a mating gear that exhibits a deviation corresponding to such a segment.

[0009] The master gear according to the invention therefore makes it possible to obtain more information, in particular less redundant, on the rolling behavior of the gearing to be tested compared to conventional rolling testing. For example, the behavior of the gearing to be tested can be tested in the case where a mating gear assigned in the fully assembled state has been manufactured for one or more gearing deviations close to the limits of the permissible tolerances.

[0010] According to one embodiment of the master gear, it can be provided that at least one of the segments has two or more teeth, wherein the two or more teeth are arranged in particular adjacent to one another, or each of the segments has two or more teeth, wherein the two or more teeth of a respective segment are arranged in particular adjacent to one another.

[0011] Grouping adjacent teeth into segments has the advantage of simplifying the evaluation of the deviations determined during the rolling test, as certain deviations characteristic of a particular segment are repeated on consecutive teeth. This allows the assignment of deviations measured during the rolling test to the segments to be automated, since the number of teeth per segment and the respective segment-specific tooth geometry are known in advance.

[0012] It can be provided that the master gear has a known, segment-specific tooth geometry that has been recorded by means of tactile and / or optical coordinate measuring technology.

[0013] Every master gear is fundamentally a gear manufactured using a gear cutting process, which in turn has been manufactured within the technological capabilities of gear manufacturing and is therefore also subject to certain tolerances. While according to the state of the art, the teeth of a master gear should exhibit as few deviations as possible from the target geometry of the mating gear, thus ensuring that the master gear is manufactured as perfectly as possible, the invention specifically introduces deviations into the master gear, reflecting, for example, limit positions for certain gearing deviations of the mating gear within the tolerances of the mating gear.

[0014] The master gear according to the invention can therefore have a target geometry modified segment by segment, wherein segment-specific limit positions are generated at the tolerance limits for one or more gearing deviations.

[0015] According to one embodiment of the master gear, it is provided that one of the segments for at least one quality parameter of the gearing has a deviation from a predetermined target geometry which amounts to more than 50% of a maximum permissible deviation for this quality parameter, in particular more than 75% of a maximum permissible deviation for this quality parameter, in particular more than 90% of a maximum permissible deviation for this quality parameter.

[0016] One such quality parameter of the gearing can be, for example, a pitch deviation. Accordingly, a segment of the gearing, to which several adjacent teeth may be assigned, can have a pitch deviation that is more than 90% of the maximum permissible deviation for this quality parameter, "pitch deviation." This can be applied to other common quality parameters or gearing deviations listed below in order to test the behavior of the gearing to be tested with regard to these gearing deviations or a combination of several gearing deviations during the rolling test.

[0017] The quality parameters of the gearing can also be referred to as gear deviations of the gearing, provided that a quality parameter has exactly one gear deviation or that exactly one gear deviation is assigned to a quality parameter. For example, exactly one gear deviation can be assigned to a quality parameter. Alternatively, two or more gear deviations can be assigned to a quality parameter.

[0018] According to one embodiment of the master gear, it is provided that at least one of the segments, in particular exactly one of the segments, has a deviation from a predetermined target geometry for all quality parameters of the gearing, which deviation is less than 20% of a maximum permissible deviation for the quality parameters, in particular less than 10% of a maximum permissible deviation for the quality parameters, in particular less than 5% of a maximum permissible deviation for the quality parameters.

[0019] Such a segment thus represents the smallest possible deviations from the intended target geometry of the teeth of the mating gear, as would be customary for master gears according to the state of the art. This segment can therefore be used in the evaluation of rolling test results to serve as a reference or to reflect the result of a conventional rolling test with a perfect master gear. In particular, a comparison of the rolling test results of the segment manufactured close to the perfect target geometry with the results of the segment manufactured in the area of ​​a boundary position can be used to assess the sensitivity of the running behavior of the gears to be tested to the tolerances of the mating gear.

[0020] A quality parameter of the gearing can have one or more deviations selected from: profile deviations, such as the total profile deviation, the profile form deviation, the profile angular deviation, the pressure angle deviation, or the like, and / or the deviations of one or more tooth flank modifications in the profile direction, such as deviations of the crowning, the tip and / or root relief, the profile angle modification, the profile twist or the like; flank line deviations, such as the total flank line deviation, the flank line form deviation, the flank line angular deviation, the spiral angle deviation or the like and / or the deviations of one or more tooth flank modifications in the flank direction, such as deviations of the width crowning, the end relief, the flank line angular modification, the flank line twist or the like;Pitch deviations, such as individual pitch deviation, total pitch deviation, pitch jump or the like; tooth thickness deviations; radial runout deviations; axial runout deviations; flatness deviations; twisting / articulation.;

[0021] The master gear can be designed to have at least three segments or exactly three segments, and / or the master gear can be manufactured in individual parts by profile grinding. Profile grinding allows the individual gaps or teeth of the master gear to be individually manufactured, allowing different tooth geometries to be created in the different segments.

[0022] According to a second aspect, the invention relates to a method comprising the method steps: rolling test of a gear to be tested, wherein the gear to be tested rolls with a master gear and wherein the master gear is designed in the manner according to the invention.

[0023] The method according to the invention makes it possible to obtain more information, in particular less redundant information, on the rolling behavior of the gearing to be tested compared to conventional rolling testing. For example, the behavior of the gearing to be tested can be tested in the case where a mating gear assigned in the fully assembled state has been manufactured with one or more gearing deviations close to the limits of the permissible tolerances.

[0024] It can be provided that during the rolling test a rotation angle of the gearing to be tested and / or the master gear is recorded, that rotation angle ranges are assigned to the segments and that, based on the rotation angle ranges, a segment-specific evaluation of the deviations recorded by means of the rolling test is carried out and segment-specific deviations are indicated.

[0025] According to one embodiment of the method, the rolling test may include a single-flank rolling test. According to one embodiment of the method, the rolling test may include a double-flank rolling test.

[0026] It can be provided that for at least one segment-specific evaluation or for several segment-specific evaluations, one or more of the deviations listed below are determined: concentricity, rolling deviation, radial runout error, tooth-to-tooth amplitude, maximum rolling deviation, transmission error and dynamic backlash, noise behavior, surface defects.

[0027] According to one embodiment of the method, it can be provided that an automated assignment of the segments to deviations measured on the gearing to be tested takes place, wherein in particular a marking of the master gear and a marking of the gearing to be tested, which enable an assignment of the teeth in engagement, are recorded.

[0028] Alternatively or additionally, the segments can be assigned to corresponding rotation angle ranges based on the measured deviations. This is because for certain segments whose gearing deviations were manufactured at the limit of a tolerance zone, characteristic rotation errors are to be expected, which change abruptly at the transition to the other segments that do not exhibit these gearing deviations at the limit of a tolerance zone.

[0029] The invention is described in more detail below with reference to exemplary embodiments of the drawings. They show schematically: Fig. 1 a master gear according to the invention; Fig. 2 the master gear according to the invention from Fig. 1 with segments; Fig. 3 a single flank rolling test; Fig. 4 a result of a single flank rolling test.

[0030] Fig. Figure 1 shows a master gear 100 according to the invention. The master gear 100 is used for the rolling test of gears. The master gear 100 has a toothing 102 with a plurality of teeth 104. The teeth 104 of the master gear 100 are numbered 1-12 in a counterclockwise direction. Each of the teeth 104 has a left flank 106 and a right flank 108.

[0031] The master gear 100 has three segments 110, 112, 114, wherein each of the segments 110, 112, 114 is assigned a plurality of teeth 104 of the plurality of teeth 104.

[0032] Segment 110 is assigned teeth 104 with numbers 4, 5, 6, 7, and 8. Segment 112 is assigned teeth 104 with numbers 9, 10, and 11. Segment 114 is assigned teeth 104 with numbers 1, 2, 3, and 12.

[0033] The teeth 104 of segment 110 have a geometry that is different from the geometry of the teeth 104 of segments 112 and 114. The teeth 104 of segment 112 have a geometry that is different from the geometry of the teeth 104 of segment 114.

[0034] Within each segment 110, 112, 114, the associated teeth 104 of the respective segment each have the same geometry. The master gear 100 therefore has three different tooth geometries.

[0035] The teeth 104 of a respective segment 110, 112, 114 are arranged adjacent to one another.

[0036] The different tooth geometries of the segments 110, 112, 114 serve in this case to represent limit positions in the area of ​​the edges of the maximum permissible tolerances for certain gear deviations in order to be able to evaluate the effects of these deviations on the rolling behavior of the gear to be tested within the framework of a rolling test of a gear.

[0037] In this example, segment 110 serves as a reference or represents the case of a classic master gear, manufactured as precisely as possible, with the smallest possible deviations from a specified target geometry. Thus, the deviation of the teeth 104 of segment 110 for all examined quality parameters of the gearing 102 is less than 5% of a maximum permissible deviation for the quality parameters. As is usual in the case of a classic master gear, the teeth 104 of segment 110 are therefore manufactured as perfectly as possible.

[0038] For the simple and easy-to-understand example of a pitch deviation, the following applies to segment 110: the tooth pitch on the pitch circle D is essentially free of deviation and thus the manufactured actual pitch P IST equal to the required target pitch P SOLL is.

[0039] In contrast, for segment 112, it is provided that for the quality parameter “tooth pitch” between the respective teeth 104, an individual pitch deviation f PT which is greater than 75% of the maximum permissible individual part deviation f PT_max .

[0040] The segment 114 has essentially no pitch error, but has a profile angle deviation f for each of the teeth 104 of the segment 114 Ha which is greater than 75% of a maximum permissible profile angle deviation f Ha_max .

[0041] Segments 112 and 114 therefore have limit positions for the pitch deviation and the profile angle deviation at the edges of the maximum permissible deviations for these quality parameters in order to determine their effect on the rolling behavior of a gear under test during the rolling test. The essentially deviation-free segment 110 serves as a reference.

[0042] The precise actual geometry of the master gear 100 can be recorded using a gear measurement. For this purpose, an optical gear measurement device 200 can be used, for example. Alternatively or additionally, a tactile gear measurement device 300 can be used. The tactile gear measurement device 300 and / or the optical gear measurement device 200 can be part of a coordinate measuring machine with a rotary table. During the measurement, the master gear to be measured can be clamped on the rotary table and rotated around its own axis using the rotary table.

[0043] Fig. 3 shows a method according to the invention - namely carrying out a single-flank rolling test of a toothed component 400 using the master gear 100 according to the invention.

[0044] The master gear 100 has a helical toothing, as shown in the schematic representation according to Fig. 1 and Fig. 2. The design of the master gear 100 is not relevant to the invention. The master gear 100 can therefore be a straight-toothed spur gear, a helical-toothed spur gear, a bevel gear, or the like. This equally applies to the method according to the invention, which is also not limited by the design or type of gearing.

[0045] Fig. 3 shows an example of the schematic structure of a test bench 16 for carrying out a single flank rolling test.

[0046] The test bench 16 has a first drive 18 and a second drive 20. The first drive 18 is configured to drive a first shaft 22 on which the toothed component 400 to be tested is mounted.

[0047] The second drive 20 serves to brake the master gear 100, which is mounted on a second shaft 26 coupled to the drive 20.

[0048] The master gear 100 is an externally toothed spur gear that meshes with the teeth of component 400. By driving the toothed component 400 and simultaneously braking the master gear 100, a speed and torque can be set during the test run. It goes without saying that speed and torque curves are also adjustable. The center distance a1 between the shafts 22, 26 is constant.

[0049] The test bench 16 has rotary encoders or angle measuring systems 28, a rotational acceleration sensor 30, and a structure-borne sound sensor 32.

[0050] Fig. 4 shows, by way of example and schematically, the measured rotational error F in [µm] plotted against one revolution U of the gear 400 - ie a result of a single-flank rolling test of the toothed component 400. From this, values ​​for the first-order runout error Fr', the tooth-to-tooth amplitude fi' and the maximum rolling deviation Fi' can be determined in a known manner.

[0051] The result shown by the Fig. 4 is only an example and does not reflect the actual result of a rolling test of a gear 400 with the Fig. 2. This is because the segment-specific deviations of the master gear 100 according to Fig.2 are to be understood merely as examples to illustrate the inventive concept. Thus, for each of the segments 110, 112, 114, a superposition of various gear deviations can be provided in order to determine their influence on the rolling behavior of a respective gear 400 to be tested.

[0052] An automated assignment of the segments 110, 112, 114 to deviations measured on the gearing 400 to be tested can be carried out, wherein a marking M1 of the master gear 100 and a marking M2 of the gearing 400 to be tested are recorded, which enable an assignment of the teeth in engagement. REFERENCE SYMBOL 16 test bench 18 first drive 20 second drive 22 first wave 26 second wave 28 Angle measuring system 30 rotational accelerometers 32 structure-borne sound sensor 100 master gear 102 Gearing 104 teeth 106 Left flank 108 Right flank 110 segments 112 segments 114 segments 200 optical device for gear measurement 300 tactile device for gear measurement 400 Gear / gearing to be tested / toothed component a1 center distance

Claims

[1] Master gear for rolling testing of gears, - wherein the master gear (100) has a toothing (102) with a plurality of teeth (104), characterized by , that - the master gear (100) has at least two segments (110, 112, 114), - wherein each of the segments (110, 112, 114) is assigned one tooth (104) or several teeth (104) of the plurality of teeth (104) and - wherein the at least one tooth or teeth (104) of one of the segments (110, 112, 114) have a geometry that is different from the geometry of the at least one tooth or teeth (104) of another of the segments (110, 112, 114). [2] Master gear according to claim 1, characterized by , that - at least one of the segments (110, 112, 114) has two or more teeth (104), wherein the two or more teeth (104) are arranged in particular adjacent to one another or - each of the segments (110, 112, 114) has two or more teeth (104), wherein the two or more teeth (104) of a respective segment (104) are arranged in particular adjacent to one another. [3] Master gear according to one of the preceding claims, characterized by , that - one of the segments (110, 112, 114) for at least one quality parameter of the gearing (102) has a deviation from a predetermined target geometry which amounts to more than 50% of a maximum permissible deviation for this quality parameter, in particular more than 75% of a maximum permissible deviation for this quality parameter, in particular more than 90% of a maximum permissible deviation for this quality parameter and / or - at least one of the segments (110, 112, 114) has a deviation from a predetermined target geometry for all quality parameters of the gearing (102) which is less than 20% of a maximum permissible deviation for the quality parameters, in particular less than 10% of a maximum permissible deviation for the quality parameters, in particular less than 5% of a maximum permissible deviation for the quality parameters. [4] Master gear according to claim 3, characterized by , that - a quality parameter of the gearing (102) has one or more deviations selected from: - Profile deviations, such as the total profile deviation, the profile form deviation, the profile angle deviation, the pressure angle deviation, or the like, and / or the deviations of one or more tooth flank modifications in the profile direction, such as deviations of the crowning, the tip and / or root relief, the profile angle modification, the profile twisting or the like; - Tooth flank deviations, such as the total tooth flank deviation, the tooth flank form deviation, the tooth flank angle deviation, the helix angle deviation or the like and / or the deviations of one or more tooth flank modifications in the flank direction, such as deviations of the width crowning, the end relief, the tooth flank angle modification, the tooth flank twist or the like; - pitch deviations, such as the individual pitch deviation, the total pitch deviation, the pitch jump or the like; - Tooth thickness deviations; - runout deviations; - axial runout deviations; - flatness deviations; - Twisting / entanglement. [5] Master gear according to one of the preceding claims, characterized by , that - the master gear has at least three segments (110, 112, 114) or has exactly three segments (110, 112, 114) and / or - the master gear (100) has been manufactured individually by profile grinding. [6] Procedure, with the following steps: - Rolling test of a gear to be tested (400), - wherein the gearing (400) to be tested rolls with a master gear (100) and - wherein the master gear (100) is designed according to one of the preceding claims 1-5. [7] Method according to claim 6, characterized by , - that during the rolling test a rotation angle of the gearing (400) to be tested and / or of the master gear (100) is recorded, - that the segments (110, 112, 114) are assigned rotation angle ranges and - that a segment-specific evaluation of the deviations recorded by means of rolling test is carried out on the basis of the rotation angle ranges and segment-specific deviations are stated. [8] Method according to claim 6 or claim 7, characterized by that the rolling test includes a single-flank rolling test. [9] Method according to claim 8, characterized by that for at least one segment-specific evaluation or for several segment-specific evaluations one or more of the deviations listed below are determined: radial runout, rolling deviation, radial runout error, tooth-to-tooth amplitude, maximum rolling deviation, transmission error and dynamic backlash, noise behavior, surface defects. [10] Method according to one of the preceding claims 6-9, characterized by , that - an automated assignment of the segments (110, 112, 114) to deviations measured on the gearing (400) to be tested is carried out, - wherein in particular a marking of the master gear (100) and a marking of the toothing (400) to be tested are detected, which enable an assignment of the teeth in engagement.

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