Method for manufacturing and mounting a ball bearing around a rotating shaft by press fit

Abstract

The invention relates to a method comprising an operation (OP1) for nominally manufacturing a ball bearing (5) and a rotating shaft (3). This is followed by a modelling-based operation (MD) of identifying (OP2) a deformed raceway (P2) deformed from a nominal raceway (P1) against which the balls abut the inner ring (6b), the deformed raceway being deformed due to a set value force for press-fitting the inner ring (6b) around the rotating shaft (3); and identifying (OP3) a corrected raceway (P3) against which the balls abut the inner ring (6b), the corrected raceway being corrected by subsequently performing a correction (OP4) of the shape of the nominal raceway (P1) such that the nominal raceway (P1) is restored in a station for press-fitting the ball bearing (5) around the rotating shaft (3).

Description

Technical Field

[0001] This invention relates to the field of ball bearings, or by analogy, to the field of roller bearings or needle roller bearings. More specifically, this invention relates to a method for manufacturing at least one of the components of a component structure assembly comprising a rotating shaft and a ball bearing, and therefore to a method for mounting a ball bearing around a rotating shaft by press fitting. Background Technology

[0002] Known methods for mounting ball bearings around a rotating shaft include performing such mounting by press fitting. This mounting operation is based on the ball bearing surrounding the rotating shaft under stress. Typically, at a workstation for mounting ball bearings around a rotating shaft, the ball bearing and the rotating shaft are coaxial and extend axially along a common axis.

[0003] To clarify the context of the invention and the terminology commonly used in the art, a ball bearing includes a cage formed between a coaxial inner ring and an outer ring. A set of balls is housed between the inner and outer rings, these balls being circumferentially distributed around an extension axis of the ball bearing. Within the cage, a nominal bearing clearance is formed between one side of the balls and the other side of the inner and outer rings. A single ball bearing may have several sets of balls axially distributed at a distance from each other within the cage. Several ball bearings may be mounted axially apart about a rotational axis.

[0004] The concepts of "inner" and "outer" are relative to the axis of rotation of the ball bearing, which is mounted coaxially around the extended axis and / or the axis of rotation of the ball bearing. The concept of "inner" is generally applied to a position closer to the axis, as opposed to the concept of "outer" which is applied to a position further away from the axis.

[0005] When mounting at least one ball bearing around a rotating shaft by press fitting, the ball bearing is axially positioned around the rotating shaft and radially clamped to it. This clamping prevents the ball bearing from being mounted around the rotating shaft by hand or with a press. Therefore, the inner ring of the ball bearing is typically heated to expand it before mounting the ball bearing around the rotating shaft, and / or conversely, to potentially cool the rotating shaft.

[0006] It is generally known that the operation of press-fitting the inner ring of a ball bearing around a rotating shaft tends to cause deformation of the rotating shaft, which is subjected to radial stress. In this regard, see, for example, document EP4147817 (NTN-SNRROULEMENTS).

[0007] According to this document, ball bearings are mounted around a hub via a press fit. The hub includes an inner bore with splines, and the hub can be connected to a drive shaft via the splines. To prevent permanent deformation of the splines after the press fit, the rotating shaft includes sliding bearings at its ends, with the inner rings of the ball bearings axially positioned between the sliding bearings. Before the press fit operation, one of the sliding bearings is deformed by bending via a wedge inserted into the bore, so that after the press fit operation, the deformed sliding bearing returns to its initial shape under the stress it has been subjected to.

[0008] In the field of structural assemblies that consist of several parts assembled together, a persistent difficulty to overcome is the search for minimizing their space requirements, especially in the presence of rotating components whose axial extension can result in overhangs.

[0009] More specifically, consideration is given to the typical case where a structural assembly comprises several components, including at least one rotating shaft equipped with ball bearings mounted around the rotating shaft via a press fit of the inner ring of the ball bearing, the rotating shaft being intended to be axially coupled to another rotating component. To clarify the concept of a rotating component, it may be arranged in various ways, such as as a drive shaft for rotating the rotating shaft, or conversely, as a driven shaft driven by the rotating shaft, if desired.

[0010] In this context, a common solution is to connect the rotating shaft to the rotating component via a spline of complementary shapes, as described in the aforementioned document EP4147817. Another common solution is to connect the rotating shaft to the rotating component by bonding, for which the rotating shaft includes at least one axial groove formed in the mass of the rotating shaft on its periphery. It should be understood that the axial groove is typically open on the periphery of the rotating shaft.

[0011] However, it is observed here that this solution undesirably requires a significant increase in the dimensions of the component structure assemblies in the radial and / or axial directions. More specifically, the ball bearings are mounted around a splined or grooved keyed area of ​​the rotating shaft, which requires a significant increase in the radial thickness of the inner ring of the ball bearing mounted around the rotating shaft, or an axial offset of the ball bearing from the splined or grooved keyed area of ​​the rotating shaft.

[0012] Otherwise, if the ball bearing is mounted around a rotating shaft in its splined or grooved region, at least one recess is formed on the raceway where the ball abuts against the inner ring on which it rolls, and / or the raceway may be deformed overall. This is because one or more recesses are formed between the splines or by the at least one groove.

[0013] Therefore, as the rotating shaft rotates, this concavity or overall deformation of the raceway risks hindering the rotation of the balls rolling against the inner ring, and / or causing vibrations through resonance, which can be quite significant and detrimental to achieving proper rotation of the rotating shaft, and / or affecting the durability of the ball bearings and / or the rotating shaft. Summary of the Invention

[0014] In this context, according to the overview of the invention, the present invention relates to a method for manufacturing a component of a structural assembly, the structural assembly including at least one rotating shaft and at least one ball bearing, the at least one rotating shaft having at least one axial groove on its periphery. The manufacturing method is associated with a method for mounting the ball bearing around the rotating shaft in an axial region of the rotating shaft including the at least one groove by press fitting, the at least one groove forming a connection interface between the rotating shaft and a rotating component of the structural assembly.

[0015] Conventionally, it should be understood that the at least one groove is, for example, a keyway between the rotating shaft and the rotating component, or at least one groove formed, for example, by a spline arrangement of the rotating shaft. The at least one groove extends axially on the periphery of the rotating shaft parallel to the extension axis of the rotating shaft, and the at least one groove has an opening on the periphery of the rotating shaft facing outwards from the rotating shaft.

[0016] A groove is formed in the peripheral mass of the rotating shaft, extending in the direction of the axis of rotation of the rotating shaft according to a depth setting, and extending along the periphery of the rotating shaft according to a width setting. Depending on various possible alternative configurations of the at least one groove, the groove extends axially over all or part of the periphery of the rotating shaft. In other words, the groove may extend axially over the entire axial extension of the rotating shaft, or extend partially along its axial direction and have a blind bottom at at least one of its axial ends.

[0017] Based on the observations disclosed above (which form part of the approach for developing the present invention), the present invention aims to solve the problem addressed by “mounting at least one ball bearing around a rotating shaft by press fit, the rotating shaft including at least one axial groove extending around the periphery of the rotating shaft”, and to overcome the resulting difficulties.

[0018] More specifically, this invention addresses the potential formation and / or partial formation of at least one recess in the raceway on the outer periphery of the inner ring of a ball bearing, which can cause localized deformation of the raceway due to the formation of the balls. This deformation of the raceway on the surface of the inner ring on which the balls roll is caused by the presence of the at least one recess, which has an opening oriented outwards toward the rotating shaft on the periphery of the rotating shaft; and the inner ring being press-fitted around the rotating shaft, clamping the rotating shaft between the inner ring and the shaft.

[0019] Therefore, the initial operations for manufacturing ball bearings and rotating shafts are conventionally performed according to nominal characteristics that identify their structure, their arrangement, and / or their shape in a static state. In the context of this invention, after the ball bearings have been press-fitted around the rotating shaft, it is sought to maintain the corresponding structure of the ball bearings and rotating shaft as defined by their nominal characteristics.

[0020] Before mounting the ball bearing around the rotating shaft, the manufacturing method includes determining the deformation of the raceway of the surface on which the balls abut against the inner ring of the ball bearing roll, specifically taking into account the presence of at least one groove. Then, based on the identification of the deformation of the raceway, the modeling process continues to determine a shape correction for one or more nominal shapes of the ball bearing and / or the rotating shaft, at least with respect to the raceway of the surface on which the balls abut against the inner ring of the ball bearing roll.

[0021] This shape correction is identified during the modeling operation and is then preferably performed by machining, so that after the inner ring of the ball bearing is mounted around the axis of rotation by press fitting, at least the correct nominal shape of the raceway of the surface on which the balls roll against the inner ring of the ball bearing is obtained.

[0022] In other words, this shape correction is identified from the modeling so that after the ball bearing has been press-fitted around the rotating shaft, the ball bearing, in particular its inner ring and / or the rotating shaft, returns to its nominal shape, or in other words, its shape before the shape correction. The shape correction is identified, and then performed based on the modeling, so that, in particular, the nominal bearing clearance of the balls within the cage housing the ball bearing is maintained, even though the ball bearing is press-fitted around the rotating shaft and at least one groove on the rotating shaft is present.

[0023] The modeling identifies the deformation of the raceway on the surface where the ball rolls against the inner ring, and identifies shape corrections for the inner ring and / or the axis of rotation based on the previously obtained identification of the raceway deformation. The modeling is performed in particular with the following computational factors in mind:

[0024] a) To identify deformation of the raceway of the ball against the surface on which the inner ring rolls, consider at least the following in combination, at least in pairs:

[0025] -) The width of the at least one groove of the rotating shaft.

[0026] -) Preferably, the thickness of the inner ring is minimized, or in other words, the inner ring of the ball bearing extends radially around the axis of rotation along its outer periphery.

[0027] -) The material of the inner ring, and more specifically, at least its reversible plasticity under stress, and

[0028] -) Clamping force, which is applied to the rotating shaft by the inner ring press-fitted around the rotating shaft with a desired but not excessive clamping force threshold, thereby providing a firm hold of the ball bearing around the rotating shaft.

[0029] b) Then, in order to identify the shape corrections to be performed on the inner ring and / or rotating shaft of the ball bearing, at least in combination, the following should be considered:

[0030] -) The shape of the previously identified deformed raceway, and

[0031] -) The nominal ball bearing clearance setting inside the ball bearing cage. Recall that the cage is typically formed between the outer and inner rings of the ball bearing.

[0032] The shape correction of the inner ring and / or rotating shaft is preferably performed by machining in order to improve the accuracy of the shape correction of the inner ring and / or rotating shaft, which must be applied based on its prior identification through modeling.

[0033] However, it should be understood that using other techniques to perform the required shape correction is less advantageous, such as reversible plastic deformation of the inner ring and / or rotating shaft under stress, or any other techniques suitable for substantially correcting the nominal characteristics of mechanical parts, especially in the context of this invention, where the shape of the inner ring and / or rotating shaft is advantageously obtained through precise modeling after the correction to be performed has been identified.

[0034] The shape correction of the inner ring and / or the axis of rotation can be, for example, a correction of its overall shape. By way of another example:

[0035] -) The shape correction of the inner ring can be the shape correction of its inner hole, either integrally or limited to the raceway on which the ball abuts against the surface on which the inner ring rolls.

[0036] -) The shape correction of the rotating shaft may also be limited, for example, to its periphery, or in other words, to its outer peripheral surface, or to the shape of the groove, particularly with respect to the width extension of the opening of the groove intended to be oriented toward the inner ring of the ball bearing after the ball bearing has been assembled around the rotating shaft by press fit.

[0037] The indexing used to identify the relative angular positioning of the rotating shaft with respect to the rotating component to which it is connected is advantageous for positioning the inner ring of the ball bearing at an angle after the shape of the inner ring has been corrected, especially taking into account the location of the recesses that may be formed on the raceway due to the press fit of the inner ring of the ball bearing around the rotating shaft.

[0038] An advantageous application of the invention is suitable for the rotational assembly of a rotating shaft with a connecting member of a rotor of an electric machine for rotating the rotating shaft, and / or the rotational assembly of a rotating shaft with a driven shaft rotated by the rotating shaft.

[0039] Therefore, according to a preferred embodiment, at least a pair of radially opposing grooves are formed on the periphery of the rotating shaft for assembly by keying between the rotating shaft and the rotor of the electric machine and / or between the rotating shaft and the driven shaft, thereby facilitating the rotor to rotate the rotating shaft and / or the rotating shaft to rotate the driven shaft and balance the rotation.

[0040] Because the internal volume of one or more grooves is enclosed by the inner ring of a ball bearing press-fitted around the rotating shaft, radial and axial engagement between the rotating shaft and the rotor and / or between the rotating shaft and the driven shaft is achieved in a robust, efficient and durable manner.

[0041] In view of the above, the present invention relates to a method for manufacturing a component of a component structure assembly. The component structure assembly includes at least one ball bearing and at least one rotating shaft, the at least one rotating shaft having at least one axial groove on its periphery, the at least one axial groove including an opening on the periphery of the rotating shaft. The groove forms a connection interface between the rotating shaft and at least one rotating component of the component structure assembly.

[0042] Ball bearings typically include a coaxial outer ring and an inner ring, with a cage formed between the outer and inner rings, which houses at least one set of balls distributed circumferentially around an extended axis of the ball bearing.

[0043] At least the inner ring of the ball bearing forms at least one surface on which the balls roll against the outer surface of the inner ring. A nominal bearing clearance is formed between the balls and the cage that houses the balls. It should be understood that the nominal bearing clearance is formed between the balls on one side and the inner and outer rings of the ball bearing on the other side.

[0044] This manufacturing method relates to a method for coaxially mounting a ball bearing around a rotating shaft in an axial region of the shaft, including at least one groove, the opening of which is oriented toward an inner ring. The inner ring radially closes the opening of the groove in the axial region surrounded by the inner ring, thereby limiting the internal volume of the at least one groove.

[0045] The manufacturing method includes initial operations: manufacturing ball bearings according to nominal characteristics, and manufacturing a rotating shaft according to nominal characteristics based on the tight axial fit of the rotating shaft within the inner ring.

[0046] In this context, the invention is characterized in that, prior to mounting the ball bearing around the rotating shaft at least in the region of the rotating shaft including the at least one groove by press fitting, the manufacturing method includes determining the following operations through modeling:

[0047] -) In the first modeling step, deformed raceways of the nominal raceways of the surface on which the ball rolls against the inner ring are identified. These deformed raceways are caused by the clamping force setpoint applied to the rotating shaft by the inner ring press-fitted around the rotating shaft and / or by the presence of at least one groove.

[0048] -) In the second modeling step, taking into account the previously determined identification of deformed raceways, the corrected raceways of the surface on which the balls roll against the inner ring are identified by shape correction of at least the nominal raceway of the surface on which the balls roll against the inner ring, based on the recovery of the nominal raceway of the surface obtained at the workstation used to press-fit the ball bearing around the rotating shaft.

[0049] Other specific features of the invention (which are not limiting or restrictive) are as follows.

[0050] By means of non-limiting instructions, the deformation of the deformable raceway is identified through modeling, taking into account at least any combination, at least in pairs, the following computational factors:

[0051] -) The width of the opening of the at least one groove of the rotating shaft.

[0052] -) It is advantageous to seek the smallest possible thickness for the inner ring.

[0053] -) The material of the inner ring should at least indicate its reversible plasticity under stress.

[0054] -) The material of the rotating shaft, at least specifying its reversible plasticity under stress, and

[0055] -) Clamping force setting, which is applied to the rotating shaft by the inner ring press-fitted around the rotating shaft with a predefined but not excessive clamping force threshold, provides a firm hold of the ball bearing around the rotating shaft.

[0056] By way of non-limiting indication, the identification of corrected raceways takes into account at least the calculation factors related to deformed raceways and the calculation factors related to the nominal bearing clearance formed between the balls and the cage that houses the balls of the ball bearing. It should be understood that the nominal bearing clearance is formed between the balls on one side and the inner and outer rings of the ball bearing on the other side.

[0057] Specifically, the shape correction of at least the nominal raceway of the surface on which the ball rolls against the inner ring is performed by correcting the shape of at least one of the inner ring and / or the rotating shaft of the ball bearing, based on the previously identified corrected raceway.

[0058] The shape correction of the inner ring of a ball bearing is, for example, the overall shape correction of the inner bore of the inner ring of the ball bearing. Overall shape correction of the inner ring, or not only the inner ring but also the overall shape correction of the outer ring, should not be excluded.

[0059] The shape correction of the inner ring of a ball bearing is, for example, the shape correction of the inner bore of the inner ring of the ball bearing, limited to the extension of the nominal raceway of the surface on which the balls roll against the inner ring.

[0060] Shape correction of a rotating axis is, for example, overall shape correction of the shape of the rotating axis.

[0061] Shape correction of the rotating shaft is, for example, shape correction of the opening of at least one groove of the rotating shaft.

[0062] The shape correction of at least one of the inner ring and / or rotating shaft of the ball bearing is more specifically preferably performed by machining.

[0063] By applying the invention to a non-limiting example of the component structure assembly to be assembled together, the component structure assembly includes an electric machine that associates a stator and a rotor. The rotor includes a member for engaging the rotor to a rotating shaft. The volume of the engaging member is calibrated according to a nominal volume at least equal to the internal volume of the at least one recess, the opening of which is closed by an inner ring.

[0064] In other words, the manufacture of the coupling member within its nominal volume is related to the manufacture of the rotating shaft, and more specifically to the operation of forming the at least one groove on the periphery of the rotating shaft. At the workstation where the coupling member is assembled with the rotating shaft, the coupling member is either clamped or at least confined within the at least one groove, and the coupling member is securely held between the rotating shaft and the inner ring of a ball bearing mounted around the rotating shaft by press fitting. Attached Figure Description

[0065] The invention will be better understood by referring to the following detailed description of exemplary embodiments in conjunction with the accompanying drawings:

[0066] [ Figure 1[This is an exemplary illustration in the context of the invention being applied to an electric machine (partially shown). According to this example, the component structure assembly includes at least an electric machine that associates a stator and a rotor to rotate a rotating shaft. To enable rotation, the rotating shaft is connected to the rotor via engaging members received within peripheral axial recesses of the rotating shaft, each peripheral axial recess having an opening oriented toward a ball bearing, which is press-fitted around the rotating shaft.]

[0067] [ Figure 2 [This shows the method] Figure 1 The component shown is a ball bearing mounted around a rotating shaft by press fitting of structural components.

[0068] [ Figure 3 [This is a simplified diagram illustrating the problem addressed by the present invention and schematically showing a method for solving that problem.] Figure 3 In the diagram, the radial profile of the raceway is illustrated using three different shapes shown schematically for informational purposes, with the balls abutting against... Figure 2 The inner ring of the ball bearing shown rolls on the raceway.

[0069] [ Figure 4 ] is a display for reference Figure 3 The flowchart illustrates a method for determining modifications to the raceway profile shape through modeling, showing different raceway profile shapes. Detailed Implementation

[0070] The accompanying drawings and their non-limiting detailed description disclose the invention according to specific embodiments that do not limit the scope of the invention. The accompanying drawings and detailed description of exemplary embodiments of the invention are intended to define exemplary embodiments of the invention more clearly than the general description given above. In addition, to avoid cluttering the drawings and thus to make them easier to read, reference numerals assigned to terms and / or concepts used to describe the invention and indicated in any of the drawings may be repeated in the description of any other drawing, and are not necessarily present in all drawings.

[0071] Figure 1 Example of a component structure assembly 1 is shown, which includes an electric motor 2, which conventionally implements a stator 2a and a rotor 2b that cooperate with each other. The rotor 2b is rotatably connected to a rotating shaft 3 via a coupling member 4, which rotates the rotating shaft. The rotating shaft 3 is provided with at least one ball bearing 5, 5a, for... Figure 1Individual ball bearings 5a are clearly marked without appearing cluttered. The ball bearings 5, 5a are mounted coaxially around the rotating shaft 3 by a press fit, A1. Due to their coaxial mounting A1, the axes of the ball bearings 5, 5a and the axis of the rotating shaft 3 are identified using a single reference numeral A1 to make the drawings easier to read and to facilitate the disclosure and / or understanding of the invention.

[0072] In order to clarify the concept of component structure assembly 1 introduced for the purpose of defining the present invention, the components of the structure assembly 1 form a functional structure by cooperating with each other in at least pairs.

[0073] In the context of this invention, the component includes at least a rotating shaft 3 and at least one ball bearing 5, 5a. The ball bearings 5, 5a of the component structure assembly 1 typically include an outer ring 6a and an inner ring 6b, with a cage 6 formed radially between the inner and outer rings to accommodate at least one set of balls 5a distributed around a circumference C1.

[0074] exist Figure 2 As can be seen more clearly, the surfaces 7a and 7b on which the balls 5a roll are formed on the inner surface of the outer ring 6a and the outer surface of the inner ring 6b, respectively. The nominal bearing clearance J1 of the balls 5a inside the cage 6 (along the circumference C1 around which the balls are distributed inside the cage 6) is formed inside the cage 6, on the one hand between the balls 5a, and on the other hand between the outer ring 6a and the inner ring 6b of the ball bearings 5 ​​and 5a.

[0075] According to the present invention Figure 1 In the exemplary application of the electric machine 2 shown, the component structure assembly 1 in this case includes components of the electric machine 2, specifically the stator 2a and the rotor 2b. The rotor 2b includes a component that forms the axial rotational engagement member 4 between the rotor 2b and the rotating shaft 3, through which the rotating shaft is rotated.

[0076] exist Figure 1 In, and Figure 2 As can be seen more clearly, ball bearings 5, 5a are mounted around the rotating shaft 3 by a press fit. For assembling the rotating shaft 3 and the rotor 2b, the rotating shaft 3 includes at least one groove 8 on its periphery for receiving the engaging member 4 of the rotor 2b. According to the example shown, the rotating shaft 3 preferably includes a pair of two radially opposing grooves 8 on its periphery. Each of the grooves 8 includes an opening 8a that opens onto the inner ring 6b press-fitted around the rotating shaft 3 on its periphery.

[0077] refer to Figure 3The problem addressed and the basis of the present invention stem from the following observation: Since the ball bearings 5 ​​and 5a are mounted around the rotating shaft 3 by press fitting via the inner ring 6b of the ball bearings 5 ​​and 5a, the nominal raceway P1 of the surface on which the ball 5a rolls against the inner ring 6b is deformed under the radial stress borne by the inner ring 6b and due to the presence of the groove 8 of the rotating shaft 3.

[0078] The deformation of the nominal raceway P1 of the surface on which the ball 5a rolls against the inner ring 6b can be generalized and / or localized by forming a recess 9 on the nominal raceway P1 of the surface on which the ball 5a rolls.

[0079] The rotating shaft 3 is clamped by the inner ring 6b, which is subjected to radial stress, resulting in deformation of the nominal raceway P1 of the surface on which the ball bearing 5a rolls. More specifically, the recess 9 is formed due to the presence of the groove 8, which forms a cavity open toward the inner surface of the inner ring 6b of the ball bearings 5, 5a.

[0080] It was then observed that the rotation of the ball 5a rolling inside the cage 6 containing the ball was subject to obstruction, because deformation of the inner ring 6b could completely or partially eliminate the nominal bearing clearance J1 formed between the ball 5a and the rings 6a, 6b constituting the ball bearings 5, 5a. It was also specifically observed that deformation of the nominal raceway P1 of the surface on which the ball 5a rolls against the inner ring 6b caused vibrations due to the rolling of the ball 5a against the inner ring 6b; these vibrations could be considerable and detrimental to achieving balanced rotation of the rotating shaft 3.

[0081] To overcome these drawbacks, the present invention provides a method for manufacturing components of the component structure assembly 1, particularly a method for manufacturing ball bearings 5, 5a and / or rotating shaft 3. To clarify and facilitate understanding of the disclosure of the invention, the disclosure of the manufacturing method relates to a technique for mounting ball bearings 5, 5a around rotating shaft 3 by press fitting, and to methods for engaging rotating shaft 3 to a drive shaft that rotates rotating shaft 3 and / or a driven shaft that is rotated by rotating shaft 3, according to various applications of the present invention to specific component structure assemblies.

[0082] Figure 3 Three raceway shapes are shown in the same figure, on which balls 5a roll against the inner ring 6b of ball bearings 5, 5a. It will be clearly understood that the three raceways shown are illustrative and not pre-determined in terms of their actual shapes, which depend on the specific application of the invention and / or on the following references. Figure 4 The described results are the identification of them through modeling.

[0083] 5a ball bearing support Figure 3The inner ring 6b of the ball bearings 5 ​​and 5a shown has the following three raceways on which it rolls:

[0084] -) The first raceway is the nominal raceway P1 obtained based on the nominal characteristics at the time of initial manufacturing of ball bearings 5, 5a (hereinafter referred to as nominal ball bearings 5, 5a);

[0085] -) The second raceway is the deformed raceway P2 caused by the mounting of the nominal ball bearings 5 ​​and 5a around the rotating shaft 3 by press fitting. As seen above, the deformation of the nominal raceway P1 is caused by the clamping stress applied to the rotating shaft 3 by the inner ring 6b of the ball bearings 5 ​​and 5a.

[0086] -) The third raceway is the corrected raceway P3 of the nominal raceway P1 before the ball bearings 5 ​​and 5a are press-fitted around the rotating shaft 3. It should be understood that the ball bearings 5 ​​and 5a press-fitted around the rotating shaft 3 include the corrected raceway P3.

[0087] Regarding the deformed raceway P2, it will be recalled that the reason why the nominal raceway P1 was deformed into the deformed raceway P2 was due to the press fit installation of the nominal ball bearings 5 ​​and 5a, which caused the overall deformation of the nominal raceway and / or the formation of local depressions 9, thus making the nominal raceway P1 deformed into the deformed raceway P2.

[0088] This allows the ball bearings 5 ​​and 5a to be mounted around the rotating shaft 3 via a press fit (OF1). Figure 4 The surface 7b on which the ball 5a rolls against the inner ring 6b matches the nominal raceway P1. The present invention proposes to correct the shape of the nominal raceway P1 to the corrected raceway P3 after the ball bearings 5, 5a have been mounted around the rotating shaft 3 by press fit with OF1.

[0089] Therefore, refer to Figure 3 and Figure 4 This invention provides a method for manufacturing ball bearings 5, 5a and / or a rotating shaft 3, wherein the ball bearings 5, 5a are intended to be press-fitted around the rotating shaft. The manufacturing method includes the following operations:

[0090] -) The OP1 ball bearing is conventionally manufactured according to the nominal characteristics C5 of the ball bearings 5, 5a, and therefore specifically the nominal characteristics include the nominal raceway P1 on which the balls 5a roll and the nominal bearing clearance J1 of the balls 5a within the cage 6 formed between the upper and lower rings of the ball bearings 5, 5a. The OP1 rotating shaft is manufactured according to the nominal characteristics C3 of the rotating shaft 3, particularly with respect to the nominal characteristics of the groove 8, and more specifically with respect to the width L1 of the opening 8a of the groove 8 oriented toward the inner ring 6b of the ball bearings 5, 5a.

[0091] -) Based on the identification of the deformed raceway P2 on which the ball 5a rolls against the inner ring 6b of the ball bearings 5, 5a, the surface 7b on which the ball 5a rolls against the inner ring 6b of the ball bearings 5, 5a is corrected OP4.

[0092] As a result of the correction to the nominal raceway P1, the surface 7b on which the balls 5a of the ball bearings 5, 5a, mounted around the rotating shaft 3 by press fitting, returns to their nominal characteristics according to the nominal raceway P1 through the deformation of the inner ring 6b of the ball bearings 5, 5a, and maintains the nominal bearing clearance J1 of the balls 5a inside the cage 6 that houses the balls. When the rotating shaft 3 is set to rotate, the risk of the balls 5a being obstructed from rolling inside the cage 6 that houses the balls is avoided, and vibration is prevented.

[0093] More specifically, in Figure 4 The method for manufacturing ball bearings 5, 5a and / or rotating shaft 3 includes the following sequential operations:

[0094] -) Operation OP1: Manufacture nominal ball bearings according to the nominal characteristic C5 of nominal ball bearings 5 ​​and 5a, and manufacture a nominal rotating shaft according to the nominal characteristic C3 of nominal rotating shaft 3, then...

[0095] -) Operation OP2: Determine the deformable raceway P2 through modeling MD. Then, Operation OP3: Determine the shape correction CF1 for nominal ball bearings 5 ​​and 5a and / or the shape correction CF2 for nominal rotating shaft 3.

[0096] -) Operation OP4: Machine the inner ring 6b and / or the nominal rotating shaft 3 to give them the corresponding mounting characteristics CM5, CM3. According to these mounting characteristics, after operation OF1, in which the ball bearings 5, 5a press-fit around the rotating shaft 3, the surface 7b on which the ball 5a rolls against the inner ring 6b matches the nominal raceway P1.

[0097] The deformation of the surface 7b on which the ball 5a rolls against the inner ring 6b, determined by modeling, takes into account at least the following calculation factors. It should be understood that these calculation factors are mentioned in a non-limiting manner, and these factors are considered at least in any combination, at least in pairs, depending on the application and / or the context in which the invention is used, or the context to which the invention relates.

[0098] Regarding the determination of the deformable raceway P2 described in OP2 through modeling, the following factors were considered:

[0099] -) The width L1 of the opening 8a of the at least one groove 8 of the rotating shaft 3.

[0100] -) Seeking the smallest possible thickness E1 for the inner ring 6b.

[0101] -) The material MA1 of the inner ring 6b of ball bearings 5 ​​and 5a shall at least indicate its reversible plasticity under stress.

[0102] -) The material MA2 of the rotating shaft 3, at least indicating its reversible plasticity under stress, and

[0103] -) Clamping force setting EF1, which is applied to the rotating shaft 3 by the inner ring 6b press-fitting around the rotating shaft 3 with a desired but not excessive clamping force threshold, thereby providing a firm hold of the ball bearings 5, 5a around the rotating shaft 3.

[0104] Regarding the determination of the OP3 correction raceway P3 through modeling, or in other words, more generally, the shape correction of the surface 7b on which the ball 5a rolls against the outer surface of the inner ring 6b, at least the following factors are considered in combination:

[0105] -) Calculation factors related to the previously identified deformed raceway P2, and

[0106] -) Calculation factors related to the nominal bearing clearance J1 between the balls 5a housed between the inner ring 6b and the outer ring 6a of the ball bearings 5, 5a.

[0107] The correction of raceway P3 is specifically achieved by correcting the shape of the inner ring 6b of the nominal ball bearings 5, 5a and / or the nominal rotating shaft 3.

[0108] For example, the calibration of the inner ring 6b of nominal ball bearings 5 ​​and 5a is as follows:

[0109] -) Its inner hole 10 for accommodating the rotating shaft 3 ( Figure 2 Overall shape correction, or

[0110] -) Shape correction of the nominal raceway P1 of the surface on which the balls 5a roll against the inner ring 6b of the nominal ball bearings 5, 5a.

[0111] By another example, the correction for nominal rotation axis 3 is as follows:

[0112] -) Overall shape correction of rotating shaft 3, or

[0113] -) Shape correction of the corresponding opening 8a of the groove 8 on the periphery of the rotating shaft 3.

Claims

1. A method for manufacturing a component of a component structure assembly (1), the component structure assembly comprising at least one ball bearing (5, 5a) and at least one rotating shaft (3), the at least one rotating shaft having at least one axial groove (8) on its periphery, the axial groove including an opening (8a) on the periphery of the rotating shaft (3), the groove (8) forming a connection interface between the rotating shaft (3) and at least one rotating component (2b) of the component structure assembly (1), the ball bearing (5, 5a) comprising a coaxial outer ring (6a) and an inner ring (6b). A cage (6) is formed between the outer ring and the inner ring, the cage accommodating at least one set of balls (5a) distributed around a circumference (C1) centered on the extended axis (A1) of the ball bearing (5, 5a). At least one surface (7b) is formed on the inner ring (6b) of the ball bearing (5, 5a), and the balls (5a) roll against the outer surface of the inner ring (6b) of the ball bearing (5, 5a) on the at least one surface. A nominal bearing clearance (J1) is formed between the balls (5a) and the ball-accommodating cage (6) of the ball bearing (5, 5a). The manufacturing method is associated with a method for coaxially (A1) mounting (OF1) the ball bearing (5, 5a) around the rotating shaft (3) in an axial region of the rotating shaft including the at least one groove (8) by press fitting, wherein the opening (8a) of the at least one groove is oriented toward the inner ring (6b) that radially closes the opening (8a) of the groove (8), thereby limiting the internal volume of the at least one groove (8). The manufacturing method includes an initial operation (OP1): manufacturing the ball bearings (5, 5a) according to nominal characteristics, and manufacturing the rotating shaft (3) according to nominal characteristics based on the tight axial fit of the rotating shaft (3) within the inner ring (6b). Its features are, Before mounting (OF1) the ball bearings (5, 5a) around the rotating shaft (3) by press fitting in a region of at least the rotating shaft including the at least one groove (8), the manufacturing method includes determining the following operations by modeling: -) In the first modeling step (OP2), a deformed raceway (P2) is identified on the nominal raceway (P1) of the surface (7b) on which the ball (5a) rolls against the inner ring (6b). This deformed raceway is caused by a clamping force set value applied to the rotating shaft (3) by the inner ring (6b) press-fitted around the rotating shaft (3) and / or by the presence of the at least one groove (8). -) In the second modeling step (OP3), taking into account the previously determined identification of the deformed raceway (P2), the corrected raceway (P3) of the surface (7b) on which the ball (5a) rolls against the inner ring (6b) is identified by shape correction of at least the nominal raceway (P1) of the surface (7b) on which the ball (5a) rolls against the inner ring (6b) based on the restoration of the nominal raceway (P1) of the surface (7b) obtained at the workstation for press-fitting the ball bearing (5, 5a) around the rotating shaft (3).

2. The manufacturing method as described in claim 1, characterized in that, The deformed raceway (P2) is identified by modeling, taking into account at least any combination, at least in pairs, the following computational factors: -) The width (L1) of the opening (8a) of the at least one groove (8) of the rotating shaft (3). -) Seek the smallest possible thickness (E1) of the inner ring (6b). -) The material (M1) of the inner ring (6b) shall at least be characterized by its reversible plasticity under stress. -) The material (M2) of the rotating shaft (3) is characterized at least by its reversible plasticity under stress, and -) Clamping force setting (EF1), which is applied to the rotating shaft (3) by the inner ring (6b) press-fitting the rotating shaft (3) with a desired but not excessive clamping force threshold, is able to provide a firm hold of the ball bearings (5, 5a) around the rotating shaft (3).

3. The manufacturing method as described in claim 2, characterized in that, The identification of the corrected raceway (P3) takes into account at least the calculation factors related to the deformed raceway (P2) and the calculation factors related to the nominal bearing clearance (J1) formed between the ball (5a) and the ball-receiving cage (6) of the ball bearing (5, 5a).

4. The manufacturing method according to any one of claims 1 to 3, characterized in that, By correcting the shape of at least one of the inner ring (6b) of the ball bearing (5, 5a) and / or the rotating shaft (3), the shape correction of at least the nominal raceway (P1) of the surface (7b) on which the ball (5a) rolls against the inner ring (6b) is performed according to the previously identified correction raceway (P3).

5. The manufacturing method as described in claim 4, characterized in that, The shape correction of the inner ring (6b) of the ball bearing (5, 5a) is the overall shape correction of the inner hole (10) of the inner ring (6b) of the ball bearing (5, 5a).

6. The manufacturing method as described in claim 4, characterized in that, The shape correction of the inner ring (6b) of the ball bearing (5, 5a) is the shape correction of the inner bore (10) of the inner ring (6b) of the ball bearing (5, 5a), limited to the extension of the nominal raceway (P1) of the surface (7b) on which the ball (5a) rolls against the inner ring (6b).

7. The manufacturing method as described in claim 4, characterized in that, The shape correction of the rotating shaft (3) is the overall shape correction of the shape of the rotating shaft (3).

8. The manufacturing method as described in claim 4, characterized in that, The shape correction of the rotating shaft (3) is limited to the shape correction of the opening (8a) of the at least one groove (8) of the rotating shaft (3).

9. The manufacturing method according to any one of claims 4 to 8, characterized in that, The shape correction of at least one of the inner ring (6b) of the ball bearing (5, 5a) and / or the rotating shaft (3) is performed by machining.

10. The manufacturing method according to any one of claims 1 to 9, characterized in that, The component structure assembly (1) includes an electric motor (2) that associates a stator (2a) with a cooperating rotor (2b), the rotor (2b) including a member (4) for engaging the rotor (2b) to the rotating shaft (3), the volume of the engaging member (4) being calibrated according to a nominal volume at least equal to the internal volume of the at least one recess (8), the opening (8a) of the at least one recess being closed by the inner ring (6b). Such that at the workstation where the connecting member (4) is assembled with the rotating shaft (3), the connecting member (4) is at least confined inside the at least one groove (8) if not clamped, and the connecting member is firmly held between the rotating shaft (3) and the inner ring (6b) of the ball bearing (5, 5a) mounted around the rotating shaft (3) by press fit.

Images