Process of chamfering a pinion.

Abstract

A method of chamfering a pinion (1) comprising a plurality of teeth (4), two neighboring teeth (4a; 4b) of the plurality of teeth (4) defining between them an inter-tooth space (5) extending between a first face (2) and a second face (3) of the pinion (1), said inter-tooth space (5) comprising a first flank (8) of a first of the two neighboring teeth (4a), a second flank (6) of the second of the two neighboring teeth (4b) located opposite the first flank (8), and a bottom (9) connecting the first flank (8) and the second flank (6), the inter-tooth space (5) comprising an end (10) on the first face (2) intended to be chamfered, said end (10) comprising an end (10a) of the first flank (8), an end (10c) of the second flank (6) and an end (10b) of the bottom (9), the method comprising the following steps: setting (E1) of a chamfering tool (12) configured to chamfer said end (10) of the inter-tooth space (5);simultaneous chamfering (E2) of the ends of the first flank, the second flank and the bottom (10a, 10c, 10b) by the parameterized tool (12). Figure for the abstract: Fig. 3;

Description

Title of the invention: Method for chamfering a pinion. Technical field

[0001] The present invention relates to the field of mechanical reducers, in particular for turbomachines, and more specifically concerns the chamfering of pinions of such reducers. STATE OF THE ART

[0002] The role of a mechanical reducer is to modify the speed and torque ratio between the input axis and the output axis of a mechanical system.

[0003] Double-flow turbomachines, in particular those having a very high bypass ratio, comprise a mechanical reducer to drive the shaft of a fan. Usually, the reducer aims to transform the so-called fast rotation speed of the shaft of a power turbine into a slower rotation speed for the shaft driving the fan.

[0004] Such a reducer comprises a central pinion, called a sun gear, a crown gear and pinions called satellites, which are engaged between the sun gear and the crown gear. The satellites are held by a frame called a planet carrier. The sun gear, the crown gear and the planet carrier are planetary gears because their axes of revolution coincide with the longitudinal axis of the turbomachine. The satellites each have a different axis of revolution equally distributed over the same operating diameter around the axis of the planetary gears. These axes are parallel to the longitudinal axis.

[0005] There are several reducer architectures. In the state of the art of double-flow turbomachines, the reducers are for example of the planetary or epicyclic type.

[0006] The reducers can be composed of one or more meshing stages. This meshing is ensured in different ways such as by contact, by friction or even by magnetic fields.

[0007] There are several types of contact meshing such as with straight, helical or herringbone teeth.

[0008] In order to avoid corner effects, it is necessary to chamfer the teeth of the pinions, and in particular the ends of these teeth as well as the inter-tooth space at the level of the faces of the pinions.

[0009] This chamfering can be done manually, by the intervention of an adjuster who files the angle of the teeth to create a chamfer all along the teeth. It can also be done by "copying", using a grinding wheel which sweeps the profile of the teeth and machines the chamfer in several passes.

[0010] However, these techniques are time-consuming and expensive, and even difficult to implement on an industrial scale (especially the manual method).

[0011] An aim of the present invention is to remedy the aforementioned drawbacks, by proposing a faster chamfering method, allowing savings in manufacturing costs and which can be used industrially.

[0012] To this end, according to a first aspect, a method is proposed for chamfering a pinion extending along a central axis, the pinion comprising a first face, a second face opposite the first face along the central axis of the pinion and a plurality of teeth extending between the first face and the second face, two neighboring teeth of the plurality of teeth defining between them an inter-tooth space extending between the first face and the second face, said inter-tooth space comprising a first flank of a first of the two neighboring teeth, a second flank of the second of the two neighboring teeth located opposite the first flank, and a bottom connecting the first flank and the second flank, the inter-tooth space comprising an end on the first face intended to be chamfered, said end comprising an end of the first flank, an end of the second flank and an end of the bottom, the method comprising the following steps: - setting a chamfering tool configured to chamfer said end of the inter-tooth space; - simultaneous chamfering of the ends of the first flank, the second flank and the bottom by the parameterized tool.

[0013] Advantageously, the chamfering tool comprises an axis of revolution and comprises a grinding tip comprising a base of diameter D, a convex piloted end and a concave wall connecting the convex piloted end to the base, the concave wall having a first radius of curvature associated with a first circle around a first center in a radial plane of the chamfering tool and the convex piloted end having a second radius of curvature associated with a second circle around a second center in the radial plane, the step of parameterizing the chamfering tool consisting of determining extrinsic parameters and intrinsic parameters of the chamfering tool.

[0014] Preferably, the determined intrinsic parameters comprise at least one of the diameter D of the base, the first radius of curvature and the positioning of the first center of the first circle in the radial plane, the second radius of curvature and the positioning of the second center of the second circle in the radial plane.

[0015] Preferably, the determined extrinsic parameters comprise at least one of a chamfering position and a chamfering orientation of the chamfering tool relative to the pinion.

[0016] Advantageously, the piloted end comprises a convex connecting portion connected to the concave wall, the axis of revolution intersecting with said piloted end at a piloted point, the chamfering position of the piloted end being the chamfering position of said piloted point relative to the central axis of the pinion and relative to the first face.

[0017] Advantageously, the chamfering orientation is an orientation of a projection of the axis of revolution of the chamfering tool relative on the one hand to the central axis of the pinion and on the other hand relative to an axis of the inter-tooth space.

[0018] Preferably, the step of setting the chamfering tool comprises the following sub-steps: - assigning an initial value to the chamfering tool parameters - simulation of chamfering an inter-tooth space by the chamfering tool configured with the initial values ​​assigned - checks that a deviation between an ideal chamfer and the simulated chamfer is less than a maximum threshold; - as long as the controlled deviation is greater than a maximum threshold, modification of at least one of the parameters of the chamfering tool and repetition of the steps of simulating a chamfering, measuring a deviation and modifying it if necessary.

[0019] In a preferred embodiment, the ideal chamfer is a 45° chamfer.

[0020] The method of the invention makes it possible to chamfer one end of an inter-tooth space. on one face of the pinion in a single plunge of the chamfering tool. This saves chamfering time and therefore minimizes the costs of the operation. In addition, since pinions generally have identical inter-tooth spaces on one or both faces, the saving in chamfering time is proportional to the number of inter-tooth spaces.

[0021] The invention also relates to a pinion comprising a first tooth and a second tooth defining between them an inter-tooth space, the inter-tooth space being chamfered according to a method as defined above.

[0022] The invention also relates to a reducer comprising a pinion as defined above. DESCRIPTION OF FIGURES

[0023] Other characteristics, aims and advantages of the invention will emerge from the following description, which is purely illustrative and non-limiting, and which must be read in conjunction with the appended drawings in which:

[0024] [Fig.l] illustrates a pinion in profile view obtained according to a method of the invention;

[0025] [Fig.2] illustrates a front view of a chamfering tool in a sprocket;

[0026] [Fig.3] illustrates a pinion in perspective with the chamfering tool;

[0027] [Fig.4] schematically illustrates the steps of the method according to the invention;

[0028] [Fig.5] illustrates in section a profile view of a portion of one end of a inter-tooth space of a pinion before chamfering, chamfered according to the method of the invention, and with an ideal chamfer;

[0029] [Fig.6] illustrates a radial section of a chamfering tool used in the method according to the invention; and

[0030] [Fig.7] illustrates the chamfering tool in a radial plane of the pinion.

[0031] Throughout the figures, similar elements bear identical references. DETAILED DESCRIPTION

[0032] Figures 1, 2 and 3 illustrate a gable 1 respectively in profile view, in front view, and in perspective. Pinion 1#:

[0033] The pinion 1 extends along a central axis X of revolution, and comprises a first face 2 and a second face 3 opposite the first face 2 along the central axis X. The first face 2 and the second face 3 are perpendicular to the central axis X.

[0034] The pinion 1 further comprises a plurality of teeth 4 arranged on the circumference of the pinion 1.

[0035] In the present application, "radial" and "axial" are used, unless otherwise indicated, in reference to the central axis X. Similarly, the terms "internal" and "external" are defined radially relative to the X axis.

[0036] Each of the teeth 4 extends axially between the first face 2 and the second face 3. Two neighboring teeth 4 of the plurality of teeth define between them an inter-tooth space 5 also extending axially between the first face 2 and the second face 3.

[0037] More precisely, each tooth 4 comprises in a clockwise direction (indicated by the arrow F in FIGS. 2 and 3) successively a first flank 6, a crest 7 and a second flank 8. The first flank 6 extends radially between a first internal end 6a and a first external end 6b, and the second flank 8 extends radially between a second internal end 8a and a second external end 8b. The first internal end 6a and the second internal end 8a are both arranged at the same first radial distance from the axis X. Similarly, the first external end 6b and the second external end 8b are both arranged at the same second radial distance from the central axis X. Preferably, the first flank 6 and the second flank 8 converge with each other as they move away from the axis X radially, so that the first external end 6b and the second outer end 8b are circumferentially closer to each other than the first inner end 6a and the second inner end 8a.

[0038] The apex 7 forms the radial end of the tooth 4, and connects the external radial ends 6b and 8b of the first flank 6 and the second flank 8 of the tooth 4. Each of the first flank 6, the second flank 8 and the apex 7 of a tooth 4 extends between the first face 2 and the second face 3 and perpendicular to them.

[0039] In the embodiment illustrated in Figures 1 to 3, the toothing of the pinion 1 is straight. However, this is not limiting, and the invention also applies to any oblique, helical, spiral-shaped or herringbone toothing. Inter-tooth space 5#:

[0040] The inter-tooth space 5 between a first tooth 4a and a second tooth 4b adjacent circumferentially (in the clockwise direction illustrated by an arrow F in the figures) of the plurality of teeth 4 comprises the second flank 8 of the first tooth 4a, a bottom 9, and the first flank 6 of the second tooth 4b, which is opposite the second flank 8 of the first tooth 4a. The bottom 9 connects the respective internal radial ends 6a and 8a of the second flank 8 of the first tooth 4a and of the first flank 6 of the second tooth 4b, which are preferably arranged at the same radial distance from the axis X. The bottom 9 extends axially between the first face 2 and the second face 3.

[0041] Each inter-tooth space 5 thus comprises a first axial end 10 on the first face 2 and a second axial end 11 on the second face 3.

[0042] The first axial end 10, respectively the second axial end 11 thus comprises: - a first portion 10a, respectively 11a, corresponding to the end of the second flank 8 of the first tooth 4a on the first face 2, respectively on the second face 3; - a second portion 10b, respectively 11b, corresponding to the end of the bottom 9 on the first face 2, respectively on the second face 3; and - a third portion 10c, respectively 11c, corresponding to the end of the first flank 6 of the second tooth 4b on the first face 2, respectively on the second face 3.

[0043] The inter-tooth space 5 is perpendicular to the first face 2 (and therefore to the second face 3), so that before chamfering, in an initial state E0, each of the first portion 10a, respectively 11a, the second portion 10b, respectively 11b, and the third portion 10c, respectively 11c, forms a right angle with vertex S between the inter-tooth space 5 and the first face 2, respectively the second face 3. [Fig.5] illustrates a sectional view of the profile of the first portion 10a before chamfering (in dotted lines) with vertex S, as an illustration, another portion 10b, 10c, 11a, 11b, 11c having a similar profile.

[0044] Chamfering is performed in the method using a chamfering tool 12 such as a grinding wheel, an example of which is illustrated in [Fig. 6] in radial section, and in Figures 2, 3 and 7 in a chamfering position and orientation in different planes. For example, the chamfering tool 12 is a cubic boron nitride or CBN grinding wheel. The 12# Chamfering Tool:

[0045] The chamfering tool 12 extends along an axis of revolution A, and comprises a body 13 and a grinding tip 14 extending at one end of the body 13. The plane of [Fig.5] is therefore a radial plane (comprising the axis of revolution A) of the chamfering tool 12.

[0046] The body 13 is for example tubular. The grinding tip 14 comprises a base 15 in contact with the body 13, a concave wall 16, and a piloted tip 17.

[0047] The base 15 is in contact with one end of the body 13 and has the same dimensions. For example, as illustrated, when the body 13 is tubular with a diameter D, the base 15 is a circular base with a diameter D.

[0048] The piloted end 17 comprises a connecting portion 18 and an end surface 19 carrying a piloted point 20.

[0049] The concave wall 16 connects the connecting portion 18 to the base 15. The connecting portion 18 connects the concave wall 16 to the end surface 19.

[0050] The concave wall 16 has a first radius of curvature RI extending from a first center CL. Due to its concavity, the concave wall 16 extends and is positioned radially (relative to the axis A) between the central axis of revolution A and the first center CL.

[0051] The connecting portion 18 is convex. More precisely, the connecting portion 18 has a second radius of curvature R2 extending from a second center C2. Due to its convexity, the second center C2 is positioned radially (relative to the axis A) between the connecting portion 18 and the central axis of revolution A.

[0052] The end surface 19 is substantially flat, perpendicular to the axis A and circular. Its center is carried by the central axis A and constitutes the axial end (along the axis A) of the chamfering object 12, and also the controlled point 20. Chamfering process#:

[0053] The present application relates to a method of chamfering the pinion 1 and more precisely the first axial end 10 and / or the second axial end 11, the steps of which are illustrated in [Fig.4], and will now be described. The chamfering of one of the first 10 or second axial ends 11 consists of the chamfering of each of the three portions 10a, 10b, 10c or 11a, 11b, 11c of the corresponding axial end 10 or 11.

[0054] To illustrate and describe this method, the description will take as an example the chamfering of a first axial end 10 of an inter-tooth space 5 in contact with the first face 2. The invention applies in the same way to the chamfering of the second axial end 11 of an inter-tooth space 5 in contact with the third face 3.

[0055] In a first step E1, a chamfering tool 12 is parameterized. More precisely, different intrinsic and extrinsic parameters of the chamfering tool 12 are determined as a function of the inter-tooth space 5 to be chamfered.

[0056] The intrinsic parameters of the chamfering tool 12 include the diameter D of the base 15 of the grinding tip 14, the positioning of the first center C1, the value of the first radius R1, the positioning of the second center C2 and the value of the second radius R2.

[0057] Further, the extrinsic parameters of the chamfering tool 12 include a positioning and a chamfering orientation of the chamfering tool 12 relative to the pinion 1.

[0058] For example, the positioning of the first and second centers C1 and C2 is determined by the definition of coordinates in the radial plane illustrated in [Fig.6], relative to the central axis of revolution A of the chamfering tool 12.

[0059] Thus, as illustrated in [Fig.6], the first center C1 is located at an axial distance X1 and a radial distance Y1 from an origin O' of the axis A defined at the piloted point 20. Similarly, the second center C2 is located at an axial distance X2 and a radial distance Y2 from the origin O' of the axis A.

[0060] The chamfering positioning of the chamfering tool 12 relative to the pinion 1 is determined by defining positioning coordinates of the driven point 20 relative to the central axis X of the pinion 1. An axial coordinate on the axis X of the pinion 1 and a radial coordinate relative to this axis X of the chamfering position of the driven point 20 are thus determined. For example, with reference to [Fig.7] which illustrates a profile sectional view of the first face 2, the driven point 20 is in the chamfering position at an axial distance a and a radial distance b relative to an origin O defined on the axis X of the pinion 1 at the center of the first face 2.

[0061] In its chamfering position, the chamfering tool 12 is in simultaneous contact with the entire first axial end 10 of the inter-tooth space 5 intended to be chamfered, that is to say in contact with each of the three corresponding portions 10a, 10b and 10c of the first axial end 10, to allow simultaneous chamfering of these three portions 10a, 10b, 10c in a single plunge of the chamfering tool 12, as will be described more precisely below.

[0062] The orientation of the chamfering tool 12 is broken down on the one hand into an orientation coordinate a of the axis of revolution A of the chamfering tool 12 relative to the central axis X of the pinion 1 taken in a radial plane P of the pinion 1 comprising the chamfering position of the driven point 20 (see [Fig.7] illustrating this plane) and on the other hand in an orientation coordinate [3 of the axis A relative to an axis E of the inter-tooth space 5 to be chamfered in a transverse plane P' of the pinion 1 comprising the chamfering position of the driven point 20 (illustrated in [Fig.2]). In this plane P', the origin O constitutes the center of the pinion 1.

[0063] More precisely, the orientation coordinate a corresponds to the angle formed, in the radial plane P of the pinion 1 comprising the chamfering position of the driven point 20, between the central axis X of the pinion 1 and a projection of the chamfering orientation of the axis A of the chamfering tool 12 occupying the chamfering position in said radial plane P.

[0064] Similarly, the orientation coordinate [3 corresponds to the angle formed in the transverse plane P' of the pinion 1 between the axis E of the inter-tooth space 5 and a projection of the chamfering orientation of the axis A of the chamfering tool 12 in said plane P'. The axis E of the inter-tooth space 5 to be chamfered is for example the axis passing through the center O of the pinion 1 in the plane P' and a midpoint of the first flank 6 of the second tooth of the inter-tooth space 5 in the plane P'.

[0065] More precisely, the first step E1 of parameterizing the chamfering tool 12 comprises several sub-steps.

[0066] In a first sub-step Eli, an initial value is assigned to at least one, preferably to each of the extrinsic and intrinsic parameters of the chamfering tool 12 previously mentioned. This initial value is assigned arbitrarily, for example as a function of the dimensions of the inter-tooth space 5 to be chamfered. For example, the diameter D may be initially set to a value between 110 and 120% of the width of the inter-tooth space 5 or greater than 0.5 millimeters of this width of the inter-tooth space 5, this width being defined between the apexes of the two teeth 4 defining between them the inter-tooth space 5 to be chamfered.

[0067] In a second sub-step E12, a simulation of chamfering of the first axial end 10 is carried out from the initialized chamfering tool 12 (whose parameters are all equal to their initial value defined in the sub-step E11) or, in the case where the chamfering tool 12 has been modified in a previous iteration, from the chamfering tool 12 modified at the end of the previous sub-step E14 (this step being described below). This simulation is preferably a digital computer simulation, for example using the digital models of the pinion 1 and the chamfering tool 12 such as their CAD (Computer Aided Design) model. A simulated chamfer 21 is thus defined, this simulated chamfer 21 extending along the three portions 10a, 10b and 10c of the first axial end 10. [Fig.5] illustrates a sectional view of the profile of the simulated chamfer 21 at the level of the first portion 10a of the first axial end 10 of the inter-tooth space 5 to be chamfered as well as an ideal chamfer 22. The profile sections of the simulated chamfer 1 at the level of the second portion 10b and the third portion 10c of the first axial end 10 to be chamfered are similar to that of the first portion 10a illustrated in [Fig.5], however the deviations from the predetermined ideal chamfer 22 may vary due to the decided orientation of the chamfering tool 12 to simulate said chamfer. More precisely, the simulated chamfer 21 is concave, due to the shape of the chamfering tool 12. Thus, for each portion 10a, 10b, 10c of the first end 10 to be chamfered, the profile of the simulated chamfer 21 is concave.

[0068] In a third sub-step E13, a deviation is checked between the simulated chamfer 21 in the sub-step E12 and a predetermined ideal chamfer 22 partially illustrated (in profile section) in [Fig.5], in order to determine whether the simulated chamfer 21 deviates from the ideal chamfer 22 by a distance greater than a maximum threshold or not. For example, the ideal chamfer 22 is a 45° chamfer between the first face 2 and the inter-tooth space 5 along the entire length of the three portions 10a, 10b and 10c of the first axial end 10 to be chamfered.

[0069] To carry out this control, a maximum chamfer 23 and a minimum chamfer 24 are also defined on either side of the ideal chamfer 22, each connecting the first face 2 to the inter-tooth space 5. The maximum chamfer 23 and the minimum chamfer 24 are parallel to the ideal chamfer 22, and preferably equidistant from this ideal chamfer 22.

[0070] The minimum chamfer 24 is located between the vertex S and the ideal chamfer 22. The ideal chamfer 22 is located between the maximum chamfer 23 and the vertex S.

[0071] The profiles of the ideal chamfer 22, the maximum chamfer 23 and the minimum chamfer 24 at the first portion 10a are also illustrated in [Fig.5].

[0072] A first maximum distance CHMAX1 can be defined between an intersection II of the maximum chamfer 23 with the inter-tooth space 5 on the one hand and the vertex S on the other hand.

[0073] A first minimum distance CHMIN1 can be defined between an intersection 12 of the minimum chamfer 24 with the inter-tooth space 5 on the one hand and the vertex S on the other hand.

[0074] A second maximum distance CHMAX2 can be defined between an intersection 13 of the maximum chamfer 23 with the first face 2 on the one hand and the vertex S on the other hand.

[0075] A second minimum distance CHMIN2 can be defined between an intersection 14 of the minimum chamfer 24 with the first face 2 on the one hand and the vertex S on the other hand.

[0076] The interval between the first maximum distance CHMAX1 and the first minimum distance CHMIN1 defines a first tolerance interval.

[0077] Similarly, the interval between the second maximum distance CHMAX2 and the second minimum distance CHMIN2 defines a second tolerance interval.

[0078] In the example in which the ideal chamfer is a 45° chamfer, the first and second tolerance intervals are identical, as are the first and second maximum distances CHMAX1 and CHMAX2 and the first and second minimum distances CHMIN1 and CHMIN2. When the ideal chamfer is not 45°, the distances may be different.

[0079] The control is carried out for example in such a way that for each plane of the simulated chamfer profile 21, at least one deviation is determined at one or more points of interest of the simulated chamfer 21 between said simulated chamfer 21 and the vertex S, then is checked to know if the simulated chamfer 21 deviates from the ideal chamfer 22 by a distance greater than a maximum threshold.

[0080] For example, a first gap El can be measured at an intersection 15 between the simulated chamfer 21 and the inter-tooth space 5. The first gap El corresponds to the distance between the vertex S and this intersection 15.

[0081] A second gap El' can also be measured at an intersection 16 of the simulated chamfer 21 and the first face 2. The second gap El' corresponds to the distance between the vertex S and this intersection 16.

[0082] For any orientation of the chamfering tool 12, at least one of these two intersections 15 and 16 corresponds, due to the concave shape of the simulated chamfer 21, to the point at which the difference between the simulated chamfer 21 and the ideal chamfer 22 is maximum, so that these two intersections 15 and 16 form the two points of interest considered on the first portion 10a.

[0083] Possibly, the points of interest considered may be different.

[0084] Identical or different points of interest may be defined on the second portion 10b and third portion 10c of the first axial end 10 to be chamfered.

[0085] Preferably, identical points of interest are considered on these portions 10b and 10c.

[0086] The first deviation El is compared to the first maximum distance CHMAX1 and to the first minimum distance CHMIN 1. The second deviation El' is compared to the second maximum distance CHMAX2 and to the second minimum distance CHMIN2.

[0087] If the first deviation El is greater than the first minimum distance CHMIN1 and less than the first maximum distance CHMAX1, and if the second deviation El' is greater than the second minimum distance CHMIN2 and less than the second maximum distance CHMAX2, then the simulated chamfer 21 extends between the minimum chamfer 24 and the maximum chamfer 23 in the profile plane considered.

[0088] This check is carried out in all of the profile planes of the three portions 10a, 10b and 10c of the first axial end 10 to be chamfered.

[0089] If in all of these planes, the simulated chamfer 21 extends between the minimum chamfer 24 and the maximum chamfer 23, then the simulated chamfer 21 is at a distance from the ideal chamfer 22 less than the maximum threshold. The extrinsic and intrinsic parameters of the chamfering tool 12 are then fixed to the values ​​of said iteration, and step E1 is finished.

[0090] If, on the contrary, in at least one of these planes, the simulated chamfer 21 is at a distance from the ideal chamfer 22 greater than the maximum threshold, then a fourth sub-step E14 is implemented.

[0091] In the fourth sub-step E14, one or more, possibly all, of the extrinsic and intrinsic parameters of the chamfering tool 12 initialized in step E1 or defined in the previous iteration of the sub-step E14 are modified.

[0092] The sub-steps E12, E13 and E14 are then repeated as long as the control of the sub-step E13 is not satisfied, that is to say as long as the simulated chamfer 21 of the current iteration is not defined as extending entirely between the maximum chamfer 23 and the minimum chamfer 24.

[0093] Thus at the end of step E1, the chamfering tool 12 is configured to chamfer the first axial end 10 and / or the second axial end 11 of the inter-tooth space 5.

[0094] The method then moves to a step E2 in which the chamfering of the first axial end 10 of the inter-tooth space 5 is carried out using the chamfering tool 12 configured in step E1. The chamfering tool 12 therefore simultaneously chamfers each of the portions 10a, 10b and 10c of the first axial end, so that the chamfer is carried out in a single plunge of the chamfering tool 12.

[0095] The chamfering of an axial end 10, 11 of an inter-tooth space 5 is therefore carried out more quickly. For the complete chamfering of a pinion 1, the operation is repeated for each axial end 10, 11 of each inter-tooth space 5, which results in a very significant saving of time as well as in significant budgetary savings for the chamfering operation.

Claims

1.

2. Claims A method of chamfering a pinion (1) extending along a central axis (X), the pinion (1) comprising a first face (2), a second face (3) opposite the first face (1) along the central axis (X) of the pinion (1) and a plurality of teeth (4) extending between the first face (2) and the second face (3), two neighboring teeth (4a and 4b) of the plurality of teeth (4) defining between them an inter-tooth space (5) extending between the first face (2) and the second face (3), said inter-tooth space (5) comprising a first flank (8) of a first of the two neighboring teeth (4a), a second flank (6) of the second of the two neighboring teeth (4b) located opposite the first flank (8), and a bottom (9) connecting the first flank (8) and the second flank (6), the inter-tooth space (5) comprising an end (10) on the first face (2) intended to be chamfered, said end (10) comprising an end (10a) of the first flank (8),one end (10c) of the second side (6) and one end (10b) of the bottom (9), the method comprising the following steps:, - setting (El) of a chamfering tool (12) configured to chamfer said end (10) of the inter-tooth space (5); - simultaneous chamfering (E2) of the ends of the first flank, the second flank and the bottom (10a, 10c, 10b) by the parameterized tool (12). Method according to claim 1, wherein the chamfering tool (12) comprises an axis of revolution (A) and comprises a grinding tip (14) comprising a base (15) of diameter D, a convex piloted tip (17) and a concave wall (16) connecting the convex piloted tip (17) to the base (15), the concave wall (16) having a first radius of curvature (RI) associated with a first circle around a first center (Cl) in a radial plane of the chamfering tool (12) and the convex piloted tip (17) having a second radius of curvature (R2) associated with a second circle around a second center (C2) in the radial plane, the step (El) of parameterizing the chamfering tool (12) consisting of determining extrinsic parameters and intrinsic parameters of the chamfering tool (12).

3. Method according to claim 2, wherein the determined intrinsic parameters comprise at least one of the diameter D of the base (15), the first radius of curvature (RI) and the positioning of the first center (Cl) of the first circle in the radial plane, the second radius of curvature (R2) and the positioning of the second center (C2) of the second circle in the radial plane.

4. A method according to one of claims 2 or 3, wherein the determined extrinsic parameters comprise at least one of a chamfering position and a chamfering orientation of the chamfering tool (12) relative to the pinion (D-

5. Method according to claim 4, in which the piloted end (17) comprises a convex connecting portion (18) connected to the concave wall (16), the axis of revolution (A) being intersecting with said piloted end (17) at a piloted point (20), the chamfering position of the piloted end (17) being the chamfering position of said piloted point (20) relative to the central axis (X) of the pinion (1) and relative to the first face (2).

6. A method according to claim 4 or 5, wherein the chamfering orientation is an orientation of a projection of the axis of revolution (A) of the chamfering tool (12) relative on the one hand to the central axis (X) of the pinion (1) and on the other hand relative to an axis of the inter-tooth space (5).

7. Method according to one of claims 2 to 6, in which the step (El) of parameterizing the chamfering tool (12) comprises the following sub-steps: - assignment (Eli) of an initial value to the parameters of the chamfering tool (12) - simulation (El2) of a chamfering of an inter-tooth space by the chamfering tool parameterized with the assigned initial values ​​- control (El3) that a difference between an ideal chamfer (22) and the simulated chamfer (21) is less than a maximum threshold; - as long as the controlled difference is greater than the maximum threshold, modification (E14) of at least one of the parameters of the chamfering tool and repetition of the simulation steps (E12) of a chamfering, measurement (E13) of a gap and modification (E14) if necessary.

8. A method according to one of claims 7, wherein the ideal chamfer is a 45° chamfer.

9. Pinion (1) comprising a first tooth (4a) and a second tooth (4b) defining between them an inter-tooth space (5), the inter-tooth space (5) being chamfered according to any one of claims 1 Q 2

10. 1 d O. Reducer comprising a pinion (1) according to claim 9.

Images