A morphological abrasive tool and its manufacturing process, and a method for retouching at least one tooth of a mechanical transmission part with such a tool

Abstract

The present invention relates to a tool (30) for reworking a mechanical transmission part (20). The tool (30) is a morphological abrasive tool comprising a body (40) shaped to an objective inter-tooth volume (13) and an abrasive (50) cooperating with the body (40). The body (40) and the abrasive (50) are configured to remove a defect in a tooth (56) that does not conform to a theoretical definition by displacement within an inter-tooth volume of the mechanical transmission part (20) delimited by this non-conforming tooth. (Shorthand figure: Figure 2)

Description

Title of the invention: Morphological abrasive tool and method of manufacturing it, and method of retouching at least one tooth of a mechanical transmission part with such a tool

[0001] The present invention relates to a morphological abrasive tool, a method of manufacturing such a tool, and a method of retouching at least one tooth of a toothed mechanical transmission part with such a tool.

[0002] Such a mechanical transmission part may take the form of a wheel or a shaft for example. In addition, such a toothed mechanical transmission part comprises a toothing provided with teeth for transmitting a mechanical torque.

[0003] Mechanical transmission systems can be produced taking into consideration extremely high dimensional, geometric and surface quality requirements with low tolerances. For example, a helicopter power transmission box may include a mechanical transmission part having teeth with complex geometry, which must be manufactured with tolerances of 4 to 25 micrometers. Producing a mechanical transmission part having complex shapes with such precision proves difficult.

[0004] By way of illustration, the manufacture of such a mechanical transmission part may comprise several dozen operations, these operations comprising steps of shaping the material, processing, welding, three-dimensional precision control and visual inspection for example. The teeth are usually formed during the final stages of manufacture. Precision machines make it possible to manufacture such a mechanical transmission part with the required precision. Precision control machines can make it possible to control a mechanical transmission part to verify in particular that all the teeth have the required dimensional, geometric and surface quality characteristics.

[0005] However, geometric and surface defects such as corrosion pits, dents, scratches may appear on one or more teeth. However, such defects are not acceptable on the functional areas of the part, and in particular on the contact areas of the teeth. To avoid scrapping the mechanical transmission part, an operator may attempt to retouch the non-standard tooth(s). Retouching may also be considered as a repair on an existing mechanical transmission part during a maintenance operation.

[0006] A retouch of a tooth can only be carried out in the presence of a sufficient reserve of material, and has an uncertain or even low success rate. If the reserve of material is too low, for example less than 25 micrometers, then the retouch is impossible and the part must be scrapped. If the retouching does not achieve the required dimensional, geometric and surface quality characteristics, then the part must also be scrapped.

[0007] To retouch a tooth with great precision, a known technique consists of manually polishing the tooth with a felt and an abrasive paste, with a stone or a cloth. Manual treatment of a tooth proves to be random. In addition, on concave or convex surfaces, this technique can generate point contact points which locally deform the geometry of the tooth. Hollow defects are also accentuated.

[0008] Other techniques can be implemented using machines.

[0009] Thus, one of these machine-assisted techniques involves honing and grinding. This technique is not applicable for teeth with complex surfaces, for example for a tooth with a circular involute profile.

[0010] One of these machine-assisted techniques involves smuritropy tribofinishing or vibro-abrasion. This technique has the disadvantage of treating the entire part, which can accentuate hollow defects. In addition, this technique only allows a small thickness of material to be removed, of the order of 0.001 millimeters at most.

[0011] One such machine-assisted technique involves abrasive flow polishing. This technique is not suitable for external shapes, is likely to accentuate recessed defects, and may generate non-uniform material removal within the required accuracies.

[0012] One of these machine-assisted techniques involves electrolytic polishing. This technique is suitable for stainless steels, and not for the case-hardened or nitrided steels used in the power transmission systems of a helicopter, for example.

[0013] Abrasive processes such as smuritropy tribofinishing, abrasive flow polishing or electrolytic polishing treat a part globally, which can tend to accentuate hollow defects. To remedy this, an operator can locally mask the part, but such an operation is delicate on complex shapes and presents random results.

[0014] Regardless of the technique, retouching a tooth on a precision mechanical transmission part is a delicate process. Precision mechanical transmission parts that need retouching often end up being scrapped in the absence of a long-awaited solution.

[0015] The invention thus aims at a tool for retouching a mechanical transmission part to be retouched, the mechanical transmission part to be retouched comprising a plurality of teeth each having to comply with a theoretical definition, each tooth having an upstream flank and a downstream flank connected by a crest, a first tooth and a second adjacent teeth which conform to said theoretical definition delimiting an objective inter-tooth volume between them, the objective inter-tooth volume being delimited by the downstream flank of the first tooth as well as the upstream flank of the second tooth and a tooth bottom connecting the downstream flank of the first tooth to the upstream flank of the second tooth. The first tooth and the second tooth may belong to the mechanical transmission part to be retouched or to a reference part.

[0016] This tool comprises a body shaped to the objective inter-tooth volume, the body being configured to eliminate a defect in a tooth to be retouched that does not conform to said theoretical definition by self-centering and displacement in an inter-tooth volume of the mechanical transmission part to be retouched delimited by this tooth to be retouched by cooperating with an abrasive.

[0017] The expression “inter-tooth volume” designates a volume delimited circumferentially by two flanks of two teeth.

[0018] For example, the teeth are teeth having a circular involute profile. For example, the mechanical transmission part to be retouched is a part with spiral-conical teeth, which is in fact complex.

[0019] The tool is thus a morphological abrasive tool comprising a body having the shape of the objective inter-tooth volume, namely the inter-tooth volume conforming to the theoretical definition, for removing material from the tooth to be retouched.

[0020] The expression "conforms to the theoretical definition" means that the associated object respects the dimensional constraints (i.e. dimensions between two points), geometric constraints (i.e. a general shape) and surface constraints imposed by the theoretical definition. In other words, on a mechanical transmission part without defects, the body perfectly and completely matches the inter-tooth volume by having the same profile as the downstream flank, the upstream flank and the tooth bottom which delimit this inter-tooth volume, to the nearest micrometer for example. The morphological body represents a negative to the nearest micrometer of the inter-tooth volume of a mechanical transmission part without defects.

[0021] To retouch an upstream flank or a downstream flank of a non-compliant tooth of a mechanical transmission part to be retouched, an operator positions the body in an inter-tooth volume delimited by this flank to be retouched. The abrasive is either integrated into the body, or arranged on the body or arranged on the tooth to be retouched. By displacement and favorable sliding in this inter-tooth volume, the body allows the abrasive to be rubbed precisely against the tooth to be retouched and thus remove material from this tooth until a tooth conforming to its theoretical definition is obtained. The conformation of the body to the objective inter-tooth volume allows self-centering of the tool in a hollow of a tooth delimited by the tooth to be retouched which guarantees contact and positioning parallel to the surface to be retouched. The body is necessary surely well positioned which allows the affected tooth to be retouched by removing material without creating a geometric defect on the tooth and its profile.

[0022] This tool does not tend to dig hollow defects, but to catch such defects.

[0023] As a result, surprisingly, such an abrasive tool can tend to solve a problem encountered at all times in the manufacture of precision mechanical parts by increasing the chances of retouching a tooth that does not conform to its theoretical definition.

[0024] The tool may include one or more of the following features, taken alone or in combination.

[0025] Alternatively, the body may comprise a material that is sufficiently elastic so as not to unduly damage a tooth.

[0026] Thus, the body may comprise a material from the silicone group.

[0027] Such a material can make it possible to produce the body with precision. In addition, this material does not risk scratching the teeth or generating significant forces on these teeth during retouching.

[0028] According to a possibility compatible with the previous ones, the tool comprises the abrasive.

[0029] This abrasive can be integrated into the body or independent of the body.

[0030] According to one variant, the abrasive may comprise grains incorporated into the body. The nature and / or size of the grains of the abrasive may be chosen as a function, for example, of the material of the tooth or the depth of the defect to be retouched.

[0031] According to another variant, an abrasive paste can be placed on the body or tooth to be retouched.

[0032] According to a possibility compatible with the previous ones, the body can be shaped to a form delimited by the downstream flank of the first tooth as well as the upstream flank of the second tooth and the tooth bottom connecting the downstream flank of the first tooth to the upstream flank of the second tooth.

[0033] According to a possibility compatible with the previous ones, the body can comprise at least one edge shaped to the crest of the first tooth or the second tooth.

[0034] The crest of a tooth is usually not functional. However, the body may have an edge shaped like a crest, for example to allow an operator to check that the tool is correctly positioned before moving it to perform a touch-up.

[0035] In addition to a tool, the invention relates to a method of manufacturing such a tool for retouching a mechanical transmission part to be retouched, the mechanical transmission part to be retouched comprising a plurality of teeth each having to comply with a theoretical definition, each tooth having an upstream flank and a downstream flank connected by a crest, a first tooth and a second adjacent tooth which comply with said theoretical definition delimiting an objective inter-tooth volume between them, the objective inter-tooth volume being delimited by the downstream flank of the first tooth as well as the upstream flank of the second tooth and a tooth base connecting the downstream flank of the first tooth to the upstream flank of the second tooth.

[0036] The manufacturing method comprises manufacturing a body shaped to the objective inter-tooth volume so that it can be self-centered and moved in an inter-tooth volume of the mechanical transmission part to be retouched delimited by a tooth to be retouched.

[0037] This method may comprise one or more of the following features, taken alone or in combination.

[0038] According to one possibility, the method of manufacturing a tool may comprise a design of an abrasive, said design of an abrasive being carried out independently of said manufacturing of the body or during said manufacturing of the body.

[0039] The abrasive may comprise grains. The nature and / or size of the grains of the abrasive may be chosen as a function, for example, of the material of the tooth and / or the depth of the defect to be retouched. For example, the method comprises determining the grains to be used as a function of the depth of the defect to be rectified and / or the material of the tooth to be retouched, possibly using an abacus or an equivalent established by testing.

[0040] Several different tools may have different grits. For example, a first tool comprising coarse grits is used initially to touch up a tooth during a first pass, then a second tool having finer grits is used in a second pass for a finer touch up.

[0041] According to a possibility compatible with the previous ones, said manufacturing may comprise a molding of said body by placing a material of the body in an inter-tooth volume, of a reference part, present between two teeth conforming to said theoretical definition.

[0042] An operator can easily manufacture a body on a reference part. For example, the operator pours a silicone mixture, a catalyst suitable for the polymerization of silicone or even an abrasive, into an inter-tooth volume of the reference part.

[0043] Alternatively, said manufacturing may comprise molding said body by placing a material of the body in an inter-tooth volume of the mechanical transmission part to be retouched, present between two teeth conforming to said theoretical definition.

[0044] This alternative is particularly interesting and innovative. The mechanical transmission part to be retouched itself then serves as a mold for the manufacture of the morphological tool. Indeed, a mechanical transmission part to be retouched usually only has a limited number of teeth to be retouched. It is then possible to use the volume between two teeth conforming to the theoretical definition to mold the body of a morphological tool. For example, the operator pours a mixture of silicone, a catalyst suitable for the polymerization of silicone or even an abrasive into an inter-tooth volume of the mechanical transmission part to be retouched between two teeth conforming to the theoretical definition.

[0045] This solution is interesting because all the teeth then have substantially the same definition after retouching. In particular, this solution is particularly suitable for maintenance so that all the teeth are substantially equivalent.

[0046] Alternatively, said manufacturing may include modeling of the objective interdental volume with a scanner on a reference part, and making of said body using said modeling.

[0047] The inter-tooth volume of a reference part can be modeled with a scanner. The body can then be produced in various ways, via a mold conformed to the modeling or by an additive manufacturing method by superimposing layers of material such as three-dimensional printing for example.

[0048] Alternatively, said manufacturing may include modeling of the objective interdental volume with a scanner on the mechanical transmission part to be retouched, and making of said body using said modeling.

[0049] An inter-tooth volume, deemed to conform to the theoretical definition, of the mechanical transmission part to be retouched itself can be modeled with a scanner. The body can then be produced in various ways, via a mold conformed to the modeling or by an additive manufacturing method by superimposing layers of material such as three-dimensional printing for example.

[0050] Alternatively, said manufacturing may comprise making said body using a plan for defining said objective inter-tooth volume.

[0051] The body can then be produced in various ways, via a mold conforming to the definition plan or by an additive manufacturing method by superimposing layers of material such as three-dimensional printing for example.

[0052] The invention also relates to a retouching method for retouching a mechanical transmission part to be retouched, the mechanical transmission part to be retouched comprising a plurality of teeth each having to comply with a theoretical definition, each tooth having an upstream flank and a downstream flank connected by a crest, a first tooth and a second adjacent tooth which conform to said theoretical definition delimiting an objective inter-tooth volume between them, the objective inter-tooth volume being delimited by the downstream flank of the first tooth as well as the upstream flank of the second tooth and a tooth bottom connecting the downstream flank of the first tooth to the upstream flank of the second tooth.

[0053] The retouching method comprises sliding a tool comprising a body conformed to the objective inter-tooth volume and an abrasive, by back and forth for example, in a non-compliant inter-tooth volume of the mechanical transmission part to be retouched between a tooth to be retouched not conforming to said theoretical definition and an adjacent tooth.

[0054] The sliding can be carried out manually by an operator. Alternatively, a conventional robot carries the tool and moves it into the non-compliant inter-tooth volume of the mechanical transmission part to be retouched.

[0055] Following the sliding, the retouching process may include a verification of conformity of the tooth to be retouched with respect to the theoretical definition, and a new sliding of said tool back and forth in the non-conforming inter-tooth volume if the tooth to be retouched is still non-conforming with the theoretical definition.

[0056] The retouching can be carried out precisely using several successive operations of material removal and verification. The verification can be carried out using standard tooth verification machines.

[0057] The invention and its advantages will appear in more detail in the context of the description which follows with examples given for illustrative purposes with reference to the appended figures which represent:

[0058] [Fig.l], a view of a mechanical transmission part having two teeth conforming to a theoretical definition,

[0059] [Fig.2], a view of a morphological abrasive tool according to the invention,

[0060] [Fig.3], a view explaining a manufacture of a morphological abrasive tool according to the invention on a reference part or the mechanical transmission part to be retouched,

[0061] [Fig.4], a view explaining a manufacture of a morphological abrasive tool according to the invention using a modeling of a reference part or of the mechanical transmission part to be retouched,

[0062] [Fig.5], a view explaining the manufacture of a morphological abrasive tool according to the invention using a definition plan, and

[0063] [Fig.6], a view explaining a method of retouching a tooth of a mechanical transmission part to be retouched using a morphological abrasive tool according to the invention.

[0064] Elements present in several distinct figures are assigned a single reference.

[0065] [Fig.l] shows a mechanical transmission part 10 comprising a first tooth 11 and a second tooth 12 both conforming to a theoretical definition. The theoretical definition defines the shape that each tooth must have, namely its dimensions in several directions, to within a tolerance of the order of 4 to 25 micrometers. These dimensions make it possible to obtain the geometry and the surface condition desired.

[0066] The first tooth 11 and the second tooth 12 each comprise a downstream flank 112, 122, an upstream flank 111, 121, and a crest 113, 123 connecting its downstream flank 112, 122 and its upstream flank 111, 121. The terms “downstream” and “upstream” are to be considered with regard to the direction of rotation ROT of the mechanical transmission part 10 relative to a casing not shown, the upstream flank of a tooth being behind the downstream flank of this tooth in this direction of rotation.

[0067] The downstream flank 112 of the first tooth 11 is further connected by a tooth base 131 to the upstream flank 121 of the second tooth 12.

[0068] The mechanical transmission part 10 comprises a volume called “objective inter-tooth volume 13” between the first tooth 11 and the second tooth 12. This objective inter-tooth volume 13 is delimited by the downstream flank 112 of the first tooth 11 as well as the tooth bottom 131 and the upstream flank 121 of the second tooth 12.

[0069] This objective inter-tooth volume 13 represents an objective inter-tooth volume to be achieved between all the teeth of a mechanical transmission part 10, the first tooth 11 and the second tooth 12 both conforming to the theoretical definition.

[0070] However, at least one tooth of a mechanical transmission part called a “mechanical transmission part to be retouched”, normally identical to the first tooth or the second tooth conforming to the theoretical definition, may have a defect. Such a tooth is called a “tooth to be retouched” to the extent that this tooth does not conform to the theoretical definition. The mechanical transmission part to be retouched may be the mechanical transmission part 10 or may normally be identical to this mechanical transmission part 10 within tolerances.

[0071] [Fig.2] shows a tool 30 for retouching a tooth to be retouched 56 of such a mechanical transmission part to be retouched 20. The teeth of this mechanical transmission part to be retouched 20 must respect the theoretical definition of the first tooth and the second tooth of [Fig.l].

[0072] The tool 30 is a morphological abrasive tool used to remove material from the tooth to be retouched 56.

[0073] This tool 30 comprises a body 40 shaped to the objective inter-tooth volume 13. This body 40 has the shape that the non-compliant inter-tooth volume delimited by the tooth to be retouched 56 should normally have, namely the shape of the objective inter-tooth volume 13 of [Fig.l].

[0074] Thus, the body 40 is shaped to a form delimited by the downstream flank 112 of the first tooth 11 as well as the upstream flank 121 of the second tooth 12 and the tooth base 131 conforming to the theoretical definition. This body 40 thus comprises a downstream face 42 identical to the upstream flank 121, an upstream face 41 identical to the downstream flank 112, and a base 43 identical to the tooth base 131 which extends from the downstream face 42 to the upstream face 4L

[0075] Optionally, the body 40 may comprise at least one edge 44, 45 shaped to at least one of the crests 113, 123 of the first tooth 11 and / or of the second tooth 12. According to the example illustrated, the tool 30 may comprise a downstream edge 45 connected to the downstream face 42 and identical to the crest 123 of the second tooth 12 and / or an upstream edge 44 connected to the upstream face 41 and identical to the crest 113 of the first tooth 11.

[0076] According to another aspect, the body 40 comprises a material from the silicone group.

[0077] Furthermore, the tool 30 comprises an abrasive 50 cooperating with the body 40.

[0078] According to the example of [Fig.2], the abrasive 50 is integrated into the body 40. This abrasive 50 comprises grains integral with the body 40 and projecting outside this body 40.

[0079] Alternatively, the abrasive 50 may be an abrasive paste disposed on the body 40 or the tooth to be retouched. For example, an abrasive paste is disposed on the body 40.

[0080] Figures 3 to 5 illustrate methods of manufacturing such a tool 30.

[0081] Regardless of the variant, this manufacturing process involves STPF manufacturing of a body 40 of the tool by conforming the body 40 to the objective inter-tooth volume 13 and an STPA design of an abrasive 50 independently of said manufacture of the body or during said manufacture.

[0082] According to [Fig.3], this STPF fabrication may comprise an STPM molding of the body 40 by placing during an STPR filling step a material of the body 40 in an inter-tooth volume 65 present between two teeth 71, 72 conforming to the theoretical definition.

[0083] For example, plates 66, 67, 68, 69 are arranged to produce a formwork around this inter-tooth volume 65. From then on, an operator places one or more materials of the tool 30 and in particular of the body 40 in the formwork. For example, the operator places silicone, possibly the grains of an abrasive 50, and a catalyst in the volume delimited by the formwork and the teeth. Alternatively, an abrasive paste is produced separately in the usual manner during an STPA manufacturing operation.

[0084] According to variants of this alternative, the teeth 71, 72 may be teeth of a reference part 75 or of the mechanical transmission part 20 to be retouched as such. When the mechanical transmission part 20 to be retouched is used, the method comprises a prior verification of the conformity of the teeth of this mechanical transmission part 20 to be retouched with a standard verification machine in order to identify two adjacent teeth conforming to the theoretical definition, the STPM molding being carried out between these two teeth.

[0085] According to the alternative of [Fig.4], this STPF manufacturing comprises STPSCAN modeling of the objective inter-tooth volume with a scanner 80 to define a three-dimensional model of the objective inter-tooth volume. As previously, the objective inter-tooth volume can be a volume of a reference part 75 or of the mechanical transmission part to be retouched 20 as such.

[0086] Therefore, this manufacturing step STPF comprises a making STPFAB1 of the body 40 using the STPSCAN modeling. The model obtained during the STPSCAN modeling can be transmitted to a three-dimensional printer 81 which makes the body 40 in the usual manner. Alternatively, a mold can be made from this STPSCAN modeling, the making STPFAB 1 then comprising a molding of the body 40 in this mold as explained previously. An abrasive paste can be made separately in the usual manner during an STPA making operation.

[0087] According to the alternative of [Fig.5], this STPF manufacturing comprises the production of a definition plan 83 of the objective inter-tooth volume with a computer design system 99 for example. Therefore, this STPF manufacturing step comprises and a STPFAB2 production of the body using the definition plan.

[0088] The body 40 can then be produced in various ways, via a mold conforming to the definition plan or by three-dimensional printing, for example with a three-dimensional printer 82. An abrasive paste can be produced separately in the usual manner during an STPA manufacturing operation.

[0089] Regardless of the manner of producing a morphological abrasive tool according to the invention, [Fig.6] illustrates a retouching method for retouching a mechanical transmission part to be retouched 20. The mechanical transmission part to be retouched 20 comprises a plurality of teeth 21 each having to comply with a theoretical definition, each tooth 21 having an upstream flank 211 and a downstream flank 212 connected by a crest 213.

[0090] However, at least one tooth 21 called “tooth to be retouched 56” does not conform to the theoretical definition.

[0091] Therefore, after the manufacture of the tool 30 on the mechanical transmission part to be retouched or not, the retouching method comprises an STPC sliding of the tool 30 in the non-compliant inter-tooth volume 55 present between the tooth to be retouched 56 and an adjacent tooth 57.

[0092] An operator moves the tool 30 one or more times, possibly back and forth in a first direction F1 then a second opposite direction F2, in order to remove material from the tooth to be retouched 56, and where appropriate from the adjacent tooth 57.

[0093] Following this STPC sliding step, the retouching process includes an STPV verification of conformity of the tooth to be retouched 56 with respect to the theoretical definition. This step can be carried out using a standard control machine 60.

[0094] If necessary, the STPC sliding and STPV verification steps are carried out several times successively, as long as the tooth to be retouched 56 does not conform to the theoretical definition.

[0095] Naturally, the present invention is subject to numerous variations as to its implementation. Although several embodiments have been described, it is understood that it is not conceivable to exhaustively identify all possible embodiments. It is of course possible to replace a means described by an equivalent means without departing from the scope of the present invention and the claims.

Claims

Claims

1. Tool (30) for retouching a mechanical transmission part to be retouched (20), the mechanical transmission part to be retouched (20) comprising a plurality of teeth (21) each having to comply with a theoretical definition, each tooth (21) having an upstream flank (211) and a downstream flank (212) connected by a crest (213), a first tooth (11) and a second tooth (12) adjacent to said theoretical definition delimiting an objective inter-tooth volume (13) between them, the objective inter-tooth volume (13) being delimited by the downstream flank (112) of the first tooth (11) as well as the upstream flank (121) of the second tooth (12) and a tooth bottom (131) connecting the downstream flank (112) of the first tooth (11) to the upstream flank (121) of the second tooth (12), characterized in that the tool (30) comprises a body (40) shaped to the objective inter-tooth volume (13),the body (40) being configured to eliminate a defect of a tooth to be retouched not conforming to said theoretical definition by self-centering and displacement in an inter-tooth volume of the mechanical transmission part to be retouched (20) delimited by this tooth to be retouched by cooperating with an abrasive (50).,

2. Tool according to claim 1, characterized in that said body (40) comprises a material from the silicone group.

3. Tool according to any one of claims 1 to 2, characterized in that said tool comprises said abrasive (50).

4. Tool according to claim 3, characterized in that said abrasive (50) is integrated into the body or independent of the body.

5. Tool according to any one of claims 1 to 4, characterized in that said body (40) is shaped to a form delimited by the downstream flank (112) of the first tooth (11) as well as the upstream flank (121) of the second tooth (12) and the tooth bottom (131) connecting the downstream flank (112) of the first tooth (11) to the upstream flank (121) of the second tooth (12).

6. Tool according to any one of claims 1 to 5, characterized in that said body (40) comprises at least one edge (44, 45) shaped to the crest (113, 123) of the first tooth (11) or of the second tooth (12).

7. Method of manufacturing a tool for retouching a workpiece mechanical transmission to be retouched (20), the mechanical transmission part to be retouched (20) comprising a plurality of teeth (21) each having to comply with a theoretical definition, each tooth (21) having an upstream flank (211) and a downstream flank (212) connected by a crest (213), a first tooth (11) and a second adjacent tooth (12) which conform to said theoretical definition delimiting an objective inter-tooth volume (13) between them, the objective inter-tooth volume (13) being delimited by the downstream flank (112) of the first tooth (11) as well as the upstream flank (121) of the second tooth (12) and a tooth bottom (131) connecting the downstream flank (112) of the first tooth (11) to the upstream flank (121) of the second tooth (12),characterized in that the manufacturing method comprises manufacturing (STPF) a body (40) shaped to the objective inter-tooth volume (13) so that it can be self-centered and moved in an inter-tooth volume of the mechanical transmission part to be retouched (20) delimited by a tooth to be retouched.,

8. Manufacturing method according to claim 7, characterized in that said manufacturing (STPF) comprises a molding (STPM) of said body (40) by placing a material of the body (40) in an inter-tooth volume (65), of a reference part (75), present between two teeth (71, 72) conforming to said theoretical definition.

9. Manufacturing method according to claim 7, characterized in that said manufacturing (STPF) comprises a molding (STPM) of said body (40) by placing a material of the body (40) in an inter-tooth volume, of the mechanical transmission part to be retouched (20), present between two teeth (71, 72) conforming to said theoretical definition.

10. Manufacturing method according to claim 7, characterized in that said manufacturing (STPF) comprises a modeling (STPSACN) of the objective inter-tooth volume with a scanner (80) on a reference part (75), and a making (STPFAB 1) of said body using said modeling.

11. Manufacturing method according to claim 7, characterized in that said manufacturing (STPF) comprises a modeling (STPSACN) of the objective inter-tooth volume with a scanner (80) on the mechanical transmission part to be retouched (20), and a production (STPFAB1) of said body using said modeling.

12. A manufacturing method according to claim 7, characterized in that said manufacturing (STPF) comprises a making (STPFAB2) of said body using a definition plane (83) of said objective inter-tooth volume.

13. A manufacturing method according to any one of claims 7 to 12, characterized in that said manufacturing method comprises making an abrasive, said making of an abrasive being carried out independently of said manufacturing of the body or during said manufacturing of the body.

14. A retouching method for retouching a mechanical transmission part to be retouched (20), the mechanical transmission part to be retouched (20) comprising a plurality of teeth (21) each having to comply with a theoretical definition, each tooth (21) having an upstream flank (211) and a downstream flank (212) connected by a crest (213), a first tooth (11) and a second adjacent tooth (12) which conform to said theoretical definition delimiting an objective inter-tooth volume (13) between them, the objective inter-tooth volume (13) being delimited by the downstream flank (112) of the first tooth (11) as well as the upstream flank (121) of the second tooth (12) and a tooth bottom (131) connecting the downstream flank (112) of the first tooth (11) to the upstream flank (121) of the second tooth (12), characterized in that the retouching method comprises sliding (STPC) of a tool (30), comprising a body (40) shaped to the objective inter-tooth volume (13) and an abrasive (50),in a non-compliant inter-tooth volume (55) of the mechanical transmission part to be retouched (20) between a tooth to be retouched (56) not compliant with said theoretical definition and an adjacent tooth (57).,

15. Retouching method according to claim 14, characterized in that following the sliding (STPC), the retouching method comprises a verification (STPV) of conformity of the tooth to be retouched (56) with respect to the theoretical definition, and a new sliding of said tool in the non-compliant inter-tooth volume if the tooth to be retouched is still non-compliant with the theoretical definition.