Motorized vehicle wheel assembly

Abstract

To provide a drive wheel assembly for a motorized vehicle that combines axial compactness, high load capacity, and good camber stiffness. A drive wheel assembly (10) for a motorized vehicle is comprised of a stationary subassembly (12) including two outer raceway surfaces (22, 24), and a rotating subassembly (14) including a wheel hub (30), two inner raceway surfaces (56, 62), and two rows of rolling elements (16, 18) arranged on two pitch surfaces PP1, PP2. One of the inner raceway surfaces is formed on an inner ring portion (36) facing a transmission bowl at annular contact surfaces (58, 60) located between the two pitch surfaces (PP1, PP2).

Description

[Technical field]

[0001] The present invention relates to a wheel assembly for a motorized vehicle. [Background technology]

[0002] A drive wheel assembly for a motorized vehicle, once mounted on the vehicle, generally consists of a fixed subassembly, intended to be fixed to the suspension elements of the vehicle and including a first outer raceway and a second outer raceway defining an axis of rotation, and a rotating assembly, rotatable relative to the fixed elements about the axis of rotation and consisting of a wheel hub, a transmission bowl, a first inner raceway opposite the first outer raceway, a second inner raceway opposite the second outer raceway, and rolling elements, with a first row of rolling elements formed between the first outer raceway and the first inner raceway, and a second row of rolling elements formed between the second outer raceway and the second inner raceway. The wheel hub has mounting surfaces for the wheel rim and the brake disc. This assembly thus typically consists of a stack of technical functions arranged along the axis of rotation from the inside to the outside of the vehicle: transmission of torque, mounting to the suspension of the vehicle, guiding in rotation, braking and rolling, which requires large dimensions in the axial direction, i.e. transversely in the coordinate system of the vehicle.

[0003] In Patent Document 1, it is proposed to shrink fit the inner ring of the second raceway onto the transmission bowl, which allows the axial size to be reduced for a given distance between the two rows of rolling elements, while allowing the pitch diameter of the row of rolling elements located on the inside of the vehicle to be increased. As long as the load capacity and camber stiffness are increasing functions of the distance between the two rows of rolling elements and the pitch diameter of the row of rolling elements, this structure provides a solution for achieving both a reduction in the axial size and good performance in load capacity and camber stiffness. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] French Patent Application Publication No. 3,052,104 Summary of the Invention [Problem to be solved by the invention]

[0005] In electric and hybrid vehicle powertrains, the drive wheels are often larger in the width direction than in internal combustion engine powertrains, which can result in shorter lateral drive shafts. Shorter drive shafts are undesirable because they increase the angle of the transmission joint. For this reason, any additional space available for locating the transmission shaft is considered favorable. This increases the need for axial compactness in drive wheel assemblies without sacrificing performance, especially load capacity and stiffness.

[0006] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a drive wheel assembly for a motorized vehicle which combines axial compactness, high load capacity and good camber stiffness. [Means for solving the problem]

[0007] To this end, according to a first aspect of the invention, 1. A drive wheel assembly for a motorized vehicle, comprising: a stationary subassembly including a first annular outer raceway surface and a second annular outer raceway surface that are centered about a common axis of rotation; a rotating subassembly rotatable relative to the fixed subassembly about the axis of rotation, the rotating subassembly having a wheel hub including a flange with a mounting surface for a wheel rim or a brake disc, the mounting flange defining a mounting surface axially oriented in a disassembly direction of the wheel rim or the brake disc, the disassembly direction being parallel to the axis of rotation, the mounting surface being tangential to an assembly reference plane perpendicular to the axis of rotation, a transmission bowl and at least one inner ring part, the inner ring part being shrink fitted onto a shrink fitted bearing of the wheel hub and supporting against the transmission bowl at an annular contact interface extending at least radially relative to the axis of rotation, a first inner ring raceway opposite the first outer ring raceway surface, and a second inner ring raceway opposite the second outer ring raceway surface and formed on the inner ring part; A drive wheel assembly for a motorized vehicle is proposed, comprising: rolling elements forming a first row of rolling elements capable of rolling on the first outer ring raceway surface and the first inner ring raceway surface, and a second row of rolling elements capable of rolling on the second outer raceway surface and the second inner raceway surface, a first pitch surface including the center of the first row of rolling elements being located at a non-zero distance L from a second pitch surface including the center of the second row of rolling elements, and in the disassembly direction, the first row of rolling elements and the second row of rolling elements are in contact with the rolling elements of the second row of rolling elements and are located on the same outside of a boundary surface of the drive wheel assembly perpendicular to the rotation axis.

[0008] According to the invention, the annular contact surface between the inner ring portion and the annular bearing surface of the transmission bowl is located at least partially, preferably completely, between the first pitch surface and the interface surface and has a maximum contact diameter DA that is larger than the diameter DF of the shrink-fit bearing and smaller than the raceway bottom diameter DI2 of the second inner ring raceway.

[0009] The maximum contact diameter DA is understood here to mean the maximum diameter observed at the effective contact area between the transmission bowl and the inner ring and measured in a plane perpendicular to the axis of rotation.

[0010] According to the invention, it is proposed to provide an inner ring part having a particular shape in the assembly, which makes it possible to arrange the second inner ring raceway radially outside the first inner ring raceway surface and to accommodate a part of the transmission bowl including the annular bearing surface in the recess formed by the inner ring part.

[0011] The first raceway surface and the first row of rolling elements are intended to be further from a vertical plane in the longitudinal center of the vehicle than the second raceway surface and the second row of rolling elements after the assembly is installed on the vehicle.

[0012] Preferably, the annular contact surface between the inner ring and the annular bearing surface of the transmission bowl is at least partially, preferably completely, located between the first pitch surface and the second pitch surface.

[0013] The pitch diameter of the first row of rolling elements is smaller, preferably significantly smaller, than the pitch diameter of the second row of rolling elements, thereby increasing the volume available to accommodate the transmission bowl. Preferably, the first outer raceway has a raceway bottom diameter DE1 that is smaller than a raceway bottom diameter DI2 of the second inner raceway.

[0014] The dimensions of the first rolling bearing formed by the first inner ring raceway, the first outer ring raceway and the first row of rolling elements and the dimensions of the second rolling bearing formed by the second inner ring raceway, the second outer ring raceway and the second row of rolling elements are adapted to the dimensions of the transmission bowl. Thus, according to one embodiment, the transmission bowl has a space containing a rolling groove, the rolling groove preferably having: The groove bottom diameter DBO is greater than the raceway bottom diameter DI1 of the first inner ring raceway surface; The groove bottom diameter DBO is smaller than the raceway bottom diameter DI2 of the second inner ring raceway surface; The groove bottom diameter DBO is greater than the maximum contact diameter DA; The groove bottom diameter DBO satisfies one or more of the following conditions.

[0015] One or the other of the two rows of rolling elements can consist of conical or cylindrical rollers, which is particularly suitable for vehicles with a high load capacity.

[0016] However, according to a preferred embodiment aimed at minimizing the torque resisting the rotation of the rotating sub-assembly, in particular for light vehicles (cars or utility vehicles), the rolling elements are balls. Preferably, the balls constituting the first row of rolling elements have a ball diameter DC1 equal to or smaller than the ball diameter DC2 of the balls constituting the second row of rolling elements. The larger diameter of the second row of balls allows the distance between the two rows of balls to be reduced, limiting the bending of the inner ring and therefore the risk of separation of the parts of the rotating sub-assembly. The outer ring raceways are preferably axially enclosed, in the sense that they each have a raceway bottom located axially midway between the axial ends of the raceway.

[0017] The inner ring is preferably a rigid metal part, for example made of steel. Shrink-fitting the inner ring into the wheel hub requires a shrink-fit bearing, which extends close to the first inner ring raceway surface in order to optimize the axial compactness of the assembly. Preferably, the inner ring has an end face axially facing in the disassembly direction and is located at a distance L1 from a plane containing a point of the annular contact surface between the inner ring and the annular bearing surface of the transmission bowl that is furthest from the rotation axis, the distance L1 being less than 1.5 times the ball diameter of the first row of balls.

[0018] According to one embodiment, the maximum contact diameter DA of the annular contact surface is smaller than twice the diameter DC1 of the first row of rolling elements plus the diameter DF of the shrink-fit bearing.

[0019] In practice, the drive wheel assembly further comprises a transmission nut and rolling bodies, the rolling bodies being guided in the space of the transmission bowl and by rolling grooves formed in the transmission nut. The rolling bodies and the transmission bowl form a transmission joint, which defines a pitch plane passing through the centers of the rolling bodies when the rotation axis of the transmission nut and the rotation axis of the transmission bowl are aligned, the pitch plane being preferably perpendicular to the rotation axis defined by the fixed subassembly. It is also possible to define the pitch diameter of a pitch circle in which the centers of the rolling bodies lie when the rotation axis of the transmission nut and the rotation axis of the transmission bowl are aligned.

[0020] Preferably, the maximum contact diameter DA of the annular contact surface is smaller than the pitch diameter DPB of the transmission joint.

[0021] To facilitate axial compactness of the assembly, the pitch surface of the transmission joint is located at a distance CA from the assembly reference plane, said distance CA being: the distance CA is smaller than the pitch diameter of the second row of rolling elements; - the distance CA is less than 7 / 13 of the axial distance measured between the assembly reference plane and the second pitch plane; the ratio of said distance CA to the distance L between said first pitch surface and said second pitch surface is less than 4.75, preferably less than 4.6; the ratio of the difference between the distance CA and the distance L2 between the assembly reference plane and the second pitch plane to the pitch diameter of the rolling elements of the second row is less than 0.45; One or more of the following conditions are met.

[0022] According to one embodiment, the annular contact surface is planar.

[0023] According to another embodiment, the annular contact surface is flared, preferably tapered, preferably with an apex angle A of: - apex angle A is between 100° and 140°; - the apex angle A is equal to the apex angle B of the frusto-conical inner surface of the transmission bowl opposite the annular bearing surface within the range of ±10°; The apex angle A satisfies one or more of the following conditions.

[0024] The radial position of the mounting surface influences the stiffness of the assembly. According to one embodiment, the ratio of the maximum contact diameter DA of the annular contact surface to the pitch diameter DP2 of the second row of rolling elements is less than 0.65.

[0025] According to one embodiment, the transmission bowl comprises a splined end which is loosely fitted, mated or shrink fitted into the splined tubular section of the wheel hub to form a splined contact surface, and the rotating subassembly preferably comprises at least one axial retaining element attached to the transmission bowl and supporting it directly or indirectly against an abutment surface of the wheel hub rotated axially in the disassembly direction. The splined contact surface preferably allows disassembly of the wheel hub. The axial retaining element may in particular consist of a head of a screw screwed into a threaded hole formed in the transmission bowl parallel to the axis of rotation or a nut screwed into a threaded section formed in the transmission bowl. It is also possible to subject one end of the transmission bowl or the wheel hub to cold deformation, resulting in an axial interference between the two parts. More generally, the end of the transmission bowl may have any cylindrical shape with a non-circular base that is attached to a tubular portion of a complementary shape in the wheel hub by loose fitting or shrink fitting and forms a contact surface with the non-circular portion, and it is desirable for the rotating subassembly to include at least one axial retention element attached to the transmission bowl and directly or indirectly support it against the abutment surface of the wheel hub axially rotated in the disassembly direction.

[0026] To achieve a particularly compact and rigid assembly, the splined contact surface has a spline pitch diameter DPC, and the annular contact surface is axially located at a distance LAB from the assembly reference plane PA such that the sum of DPC and LAB (DPC+LAB) is smaller than the pitch diameter DP2 of the second row of rolling elements; the distance measured between the end of the spline contact surface closest to the annular contact surface in the axial direction and the assembly reference surface is less than four-fifths of the length measured between the assembly reference surface and the second pitch surface; One or more of the following arrangements are provided:

[0027] According to one embodiment, the wheel hub further comprises a centering bearing for centering the brake disc or the wheel rim, which is radially rotated on the opposite side of the rotation axis and projects axially in the removal direction relative to the mounting surface. The centering bearing may, for example, be cylindrical and may consist of two cylindrical parts of different diameters, in which case the part closest to the mounting surface preferably has a larger diameter than the part furthest away and serves to center the brake disc. Other shapes of centering bearings are also conceivable. The centering bearing may also be discontinuous and may form an annular groove or grooves parallel to the rotation axis.

[0028] The mounting surface of the flange may be flat or may be formed with, for example, radial, annular, or spiral grooves, splines, grooves, or the like.

[0029] According to one embodiment, the rolling elements of the first rolling element row have contact points facing the second rolling element row with a first inner ring raceway surface and a first outer ring raceway surface located on a first contact cone having a first apex located relative to the first rolling element row, and the rolling elements of the second rolling element row have contact points facing the first rolling element row with a second inner ring raceway surface and a second outer ring raceway surface located on a second contact cone having a second apex located relative to the second rolling element row.

[0030] In practice, the fixed subassembly may have a mounting clamp extending radially relative to the first and second outer raceway surfaces. The mounting clamp is intended to mount the fixed subassembly to a suspension member of the vehicle. For this purpose, the mounting clamp is preferably provided with a mounting surface, which may have holes for mounting the component to the suspension member.

[0031] According to one embodiment, the fixed subassembly consists of a one-piece solid metal outer ring forming the first and second outer ring raceway surfaces, and preferably also forming the mounting clamp. Alternatively, it can be provided that one and / or the other of the outer ring raceway surfaces is made of an inner ring part that is shrink-fitted into a sleeve forming the mounting clamp.

[0032] According to one embodiment, the first inner raceway is formed on the wheel hub.

[0033] Alternatively, the first inner ring raceway is formed on a first inner ring part that is at least partially shrink-fitted to the wheel hub and axially supports against a shoulder of the wheel hub that faces axially towards the second row of rolling elements. The first inner ring part has a first axial end that faces axially away from the second inner ring raceway. Preferably, the first inner ring part axially supports against a shoulder of the wheel hub that faces axially towards the second row of rolling elements. This shoulder axially supports the first inner ring part.

[0034] Preferably, the wheel hub is a one-piece metal component to contribute to the rigidity of the assembly, or the hub can be a one-piece rigid composite component, such as a steel / aluminum or steel / composite combination, for example.

[0035] Preferably, the transmission bowl is a solid, metal, one-piece component.

[0036] Where appropriate, the rotating subassembly further comprises a brake disc bearing on the mounting surface, a wheel bearing on the brake disc, and components for mounting the wheel rim and brake disc to the mounting flange.

[0037] Other features and advantages of the present invention will become apparent from a reading of the following disclosure, taken in conjunction with the accompanying drawings. [Brief description of the drawings]

[0038] [Figure 1A] 1 is a longitudinal cross-sectional view of a drive wheel assembly for a motorized vehicle according to a first embodiment of the present invention; [Figure 1B] Same as FIG. 1A, but with various characteristic dimensions of the wheel assembly noted. [Diagram 2] FIG. 6 is a longitudinal cross-sectional view of a drive wheel assembly for a motorized vehicle according to a second embodiment of the present invention. [Diagram 3] FIG. 10 is a longitudinal cross-sectional view of a drive wheel assembly for a motorized vehicle according to a third embodiment of the present invention.

[0039] For greater clarity, identical or similar elements are provided with the same reference numbers in all the figures. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] FIG. 1A shows a drive wheel assembly 10 for a motorized vehicle, which is intended to be fixed to a suspension member (not shown) of the motorized vehicle and includes a fixed subassembly 12 defining a rotation axis 100, a rotating subassembly 14 rotatable about the rotation axis 100 within the fixed subassembly 12, and rolling elements 16, 18 between the rotating subassembly 14 and the fixed subassembly 12.

[0041] Here, the stationary subassembly 12 is comprised of a one-piece solid metallic outer ring 20 having coaxial first and second outer ring raceways 22, 24 that define an axis of rotation 100. The outer ring further includes at least one radially outwardly extending mounting clamp 26 having holes (not shown in this view) formed therein for mounting the mounting clamp 26 to a suspension member via a mounting element (not shown).

[0042] The rotating subassembly 14 is comprised of a wheel hub 30 , a transmission bowl 32 , a first inner race portion 34 , and a second inner race portion 36 .

[0043] The wheel hub 30 is a one-piece metal part including a flange 38 for mounting a drive wheel rim 40 and a brake disc 41. The flange 38 has a surface 42 for supporting the brake disc 41 and is provided with mounting holes 43 to allow insertion of mounting elements 143 of the rim 40 and the brake disc 41.

[0044] The wheel hub 30 also has a centering skirt 44 which projects axially relative to the plane bearing surface 42 in the disassembly direction 200 of the wheel rim 40 and the brake disc 41 and is provided with a radially outwardly facing centering bearing 45, preferably stepped. The stepped centering bearing 45 consists of a first cylindrical part for centering the wheel rim 40 and a second cylindrical part of the same or larger diameter for centering the brake disc 41 during assembly. The centering bearing 45 is not necessarily intended to remain in contact with the rim 40 and the brake disc 41 after assembly.

[0045] The transmission bowl 32 is a unitary metal component having a solid protruding end portion 46 and a flared intermediate section 48 which defines a constant velocity joint space 50.

[0046] In this embodiment, said space has a rolling groove 461 located opposite a complementary rolling groove 321 formed in the transmission joint nut 322, respectively guiding the rolling elements 323 along a concave track, for example a circular arc, located in a plane containing the rotation axis 100. In a known manner, this assembly forms a transmission joint 320 allowing the transmission of movements and torques between the nut 322 fixed to the transmission shaft 324 and the transmission bowl 32 fixed to the wheel hub 30, while in operation the transmission shaft 324 does not remain perfectly aligned with the rotation axis 100 constrained by the outer ring 20, such that the latter is supported by suspension elements that ensure one or more degrees of freedom of movement of the outer ring 20 relative to the vehicle body.

[0047] A projection 46 of the transmission bowl 32 freely mounts in a splined tubular space 47 of the wheel hub 30 and is mated or shrink fitted to define a splined contact surface.

[0048] FIG. 1A further illustrates a means for attaching the transmission bowl 32 to the wheel hub 30, which comprises a nut 88 that threads onto the threaded end 90 of the projection 46 and bears against a shoulder 84 of the wheel hub 30.

[0049] The first inner ring portion 34 is shrink-fitted into a cylindrical shrink-fit bearing 52 of the wheel hub 30 and is axially supported against an annular shoulder 54 formed in the wheel hub 30. The first inner ring portion 34 is formed with a first inner ring raceway surface 56 facing the first outer ring raceway surface 22.

[0050] The second inner ring part 36 is also shrink-fitted into the cylindrical shrink-fit bearing 52 of the wheel hub 30, with a lateral end face 57 which axially supports against the first inner ring part 34, and an annular lateral abutment surface 58 which faces axially away from the inner ring raceway surface 56 and projects axially against the wheel hub 30 so as to support against a shoulder 60 formed in the transmission bowl 32. In this embodiment, the annular lateral abutment surface 58 and the shoulder 60 are flat. A second inner ring raceway surface 62 is formed on the second inner ring part 36 opposite the second outer ring raceway surface 24. The rolling elements 16, 18 form, on the one hand, a first rolling element row 16 which rolls on the first outer ring raceway surface 22 and the first inner ring raceway surface 56, and, on the other hand, a second rolling element row 18 which rolls on the second outer ring raceway surface 24 and the second inner ring raceway surface 62.

[0051] The remainder of the discussion will focus on salient dimensional characteristics of the assembly, as shown in Figure 1B, which require some preliminary definitions. Therefore, we define them as follows: - PP1: Pitch surface on which the pitch circle forming the locus of the centers of the rolling elements 16 in the first row is located. - PP2: Pitch surface on which the pitch circle forming the locus of the centers of the rolling elements 18 in the second row is located. DP1: Pitch circle diameter of the rolling elements 16 in the first row. DP2: Pitch circle diameter of the rolling elements 18 in the second row. DC1: The diameter of the balls 16 constituting the first row of rolling elements. DC2: The diameter of the balls 18 constituting the second row of rolling elements. - PA: A plane perpendicular to the rotation axis 100 and tangent to the mounting surface 42. -PB: a plane that is perpendicular to the rotation axis 100, contacts the axial end face 57 of the second inner ring portion 36, and faces the attachment / detachment direction 200. -PL: a plane perpendicular to the rotation axis 100, which is in contact with the second row of rolling elements 18 and on the same side of which the two rows of rolling elements 16, 18 are located. -DA: the maximum diameter of the contact surface between the lateral annular abutment surface 58 formed on the second inner ring portion 36 and the annular bearing surface 60 of the transmission bowl 38, i.e. the effective contact area. -PAB: a plane perpendicular to the axis of rotation 100 and including the point of contact between the lateral annular abutment surface 58 formed on the second inner ring portion 36 and the annular bearing surface 60 of the transmission bowl 38 that is furthest from the axis of rotation (in other words, the plane on which a circle of radius DA is drawn). -DBO: The groove bottom diameter of the rolling groove formed in the space 50 of the transmission bowl 32. -DPB: Pitch diameter of the transmission joint 320, which is the diameter of a pitch circle including the center of the rolling element 323 of the transmission joint 320 when the axis of the transmission shaft 324 and the rotation axis 100 are aligned. -PPB: A plane including the pitch circle of the transmission joint 320, which is perpendicular to the rotation axis 100 when the axis of the transmission shaft 324 and the rotation axis 100 are aligned. - DI1: raceway bottom diameter of the first inner ring raceway 56, which is defined as the minimum diameter of the inner ring raceway 56. - DI2: raceway bottom diameter of the second inner ring raceway 62, and is defined as the minimum diameter of the inner ring raceway 62. DE1: raceway bottom diameter of the first outer ring raceway 22, and is defined as the maximum diameter of the outer ring raceway 22. DF: the diameter of the shrink-fit bearing 52 at the second inner ring portion 36. DPC: the spline pitch diameter (i.e. the effective contact area) of the spline contact surface between the projection 46 of the transmission bowl 32 and the splined tubular portion 47 of the wheel hub 30. LPC: the distance measured parallel to the axis of rotation 100 between the assembly reference plane PA and one end of the spline contact surface between the projection 46 of the transmission bowl 32 and the splined tubular portion 47 of the wheel hub 30 closest to the interface between the transmission bowl 32 and the second inner ring portion 36.

[0052] The outer ring raceways 22, 24 formed on the outer ring 20 are axially enclosed in the sense that they have raceway bottoms 64, 66 located at a midpoint between the axial ends of the corresponding raceway surfaces 22, 24. The rolling elements 16, 18 here are balls and the raceways 22, 24, 56, 62 are arranged to form a rolling bearing with two rows of so-called "O"-shaped angular contact balls. In other words, the contact points between the rolling elements 16 of the first row and the associated raceway surfaces 22, 56 lie on a first contact cone having a first apex located on the opposite side of the rolling elements 18 of the second row relative to the rolling elements 16 of the first row, and the contact points between the rolling elements 18 of the second row and the associated raceway surfaces 24, 62 lie on a second contact cone having a second apex located on the opposite side of the rolling elements 16 of the first row relative to the rolling elements 18 of the second row.

[0053] It should be noted that the annular bearing surface 60 for at least axially bearing the transmission bowl 32 on the second inner ring part 36 is axially arranged between the pitch surface PP1 of the first row of rolling elements 16 and the interface surface PL, preferably between the pitch surface PP1 of the first row of rolling elements 16 and the pitch surface PP2 of the second row of rolling elements. The annular bearing surface 60 is radially arranged between the shrink-fit bearing 52 of the wheel hub 30 and the second inner ring raceway 62, preferably between the shrink-fit bearing 52 and the raceway bottom diameter of the first outer ring raceway 64. Radially, this translates into the diameter DA being greater than the reduction diameter DF and smaller than the raceway bottom diameter DI2, preferably smaller than the raceway bottom diameter DE1.

[0054] This orientation gives the assembly 10 an axially compact configuration with excellent stiffness.

[0055] Preferably, a raceway bottom diameter DE1 of the first outer ring raceway surface 22 is smaller than a raceway bottom diameter DI2 of the second inner ring raceway surface 62.

[0056] The raceway bottom diameter BOD of the rolling raceway 461 formed in the space 50 of the transmission bowl 32 is the raceway bottom diameter DBO is greater than the raceway bottom diameter DI1 of the first inner ring raceway surface 56; the raceway bottom diameter DBO is smaller than the raceway bottom diameter DI2 of the second inner ring raceway surface 62; the raceway bottom diameter DBO is greater than the maximum diameter DA of the annular bearing surface 60; Meet the conditions.

[0057] In this first embodiment, the rolling elements 16, 18 are balls, the balls forming the first row of rolling elements 16 having a diameter DC1 equal to or smaller than the diameter DC2 of the balls forming the second row of rolling elements 18. By choosing a relatively small diameter for the first row of balls 16, it is possible to maintain a sufficient axial thickness of the second inner ring part 36 in the shrink-fitted area of ​​the wheel hub 30 close to the first row of rolling elements 16, so that the pitch surfaces PP1, PP2 can coincide. By choosing a larger diameter for the second row of rolling elements 18, it is possible to ensure good load-bearing properties while keeping the distance between the two pitch surfaces PP1, PP2 relatively small.

[0058] The axial end face PB of the second inner ring portion 36 is located at a distance L1 from the plane PAB that is smaller than 1.5 times the diameter DC1 of the balls of the first row of rolling elements 16.

number

[0059] The pitch surface PPB is located at a distance CA from the plane PA, and the distance CA is: the distance CA is smaller than the pitch diameter DP2 of the second row of rolling elements 18; the distance CA is equal to or smaller than 13 / 7 of the axial distance L2 measured between the abutment surface PA and the pitch surface PP2 of the rolling elements 18 of the second row; the ratio of said distance CA to the distance L between the first pitch plane PP1 and the second pitch plane PP2 is less than or equal to 4.75, preferably less than or equal to 4.6, the ratio of the difference between the distance CA and the distance L2 between the plane PA and the second pitch plane PP2 to the pitch diameter PD2 of the second row of rolling elements 18 is less than 0.45; Meet one or more of the following conditions.

number

[0060] The maximum contact diameter DA is the ratio of the diameter DA of the second row of rolling elements 18 to the pitch diameter DP2 is less than 0.65;

number

number

[0061] The pitch diameter DP2 of the second row of rolling elements 18 is greater than the sum of the spline pitch diameter DPC and the distance LAB between the planes PA and PAB.

number

[0062] A distance LPC measured in the axial direction between the end of the spline contact surface closest to the annular contact surface of the plane PAB and the assembly reference plane (PA) is less than 4 / 5 of the distance L2 between the plane PA and the pitch surface PP2 of the second row of rolling elements 18.

number

[0063] In practice, the diameter DA is smaller than the pitch diameter DPB of the transmission joint.

[0064] As a modification of the first embodiment, the first inner ring raceway 56 can be formed directly on the wheel hub 30.

[0065] In another variation, each ball 16, 18 in the second row of balls may have the same diameter.

[0066] The embodiment of FIG. 2 differs primarily from the embodiment of FIGS. 1A and 1B in that the first inner raceway 56 is formed directly in the wheel hub 30. The second inner raceway 62 is formed in the inner raceway 36, which will be referred to hereinafter for convenience as the "second" inner raceway. This second inner raceway 36 is shrink-fitted in the shrink-fit bearing 52 and bears axially against the shoulder 86 of the wheel hub 30 and also against the shoulder 60 of the transmission bowl 32. This embodiment differs secondarily from that of FIGS. 1A and 1B by the flared shape, here a frustoconical shape, of the annular abutment surface 58 and the annular bearing surface 60. Note in particular the positional relationship of the plane PAB in FIG. 2 to the dimension DA, which corresponds to the maximum circle of the contact area between the annular abutment surface 58 and the annular bearing surface 60. The apex angle A of the annular bearing surface 60 and the annular abutment surface 58 is preferably between 100° and 140°. More preferably, apex angle A is equal to within ±10° an apex angle B of the frusto-conical inner surface 61 of transmission bowl 32 opposite annular bearing surface 60 .

[0067] The characteristic dimensions given for the first embodiment are also present in the second embodiment. In particular, the contact surface occurring between the annular bearing surface 60 and the annular abutment surface 58 is located axially between the pitch surface PP1 of the first row of rolling elements 16 and the interface surface PL, preferably between the pitch surfaces PP1, PP2 of the two rows of rolling elements 16, 18, radially between the shrink-fitted bearing 52 of the wheel hub 30 and the second inner ring raceway 62, preferably between the shrink-fitted bearing 52 and a transverse plane including the raceway bottom diameter of the first outer ring raceway 64.

[0068] The embodiment of Fig. 3 is a modification of the embodiment of Fig. 2, in which the diameters of the balls of the two rows of rolling elements 16, 18 are equal to each other. In this case, the axial compactness is slightly inferior to that of the second embodiment, but the mounting of the rolling bearing is simplified and the risk of making an error in the selection of balls is eliminated.

[0069] 3 shows the means for fixing the connection between the wheel hub 30 and the transmission bowl 32, which implement a screw 76 which engages in a threaded hole 78 in the projection 46 of the transmission bowl 32 and whose head 80 bears against a shoulder 84 of the wheel hub facing away from the transmission bowl 32. These fixing means can be transferred to all the embodiments.

[0070] It will be understood that the examples shown in the drawings and described above are provided for illustrative and non-limiting purposes only.

[0071] Alternatively, it is possible to provide a multi-part fixing subassembly including a one or more part clamp 26 forming a mounting clamp to a suspension element of the vehicle, and two coaxial outer rings shrink fitted into said clamp.

[0072] Furthermore, one or the other of the two rows of rolling elements 16, 18 can be constituted by rolling elements having an axis of rotational symmetry, and the center of each rolling element can be defined as the center of gravity of the rolling element, and the diameter measured on a plane perpendicular to the axis of rotational symmetry of the rolling element and passing through the center of gravity of the rolling element can be defined as the rolling element diameter.

[0073] It is explicitly indicated that the various illustrated embodiments can be combined to provide other embodiments. For example, the mounting aspects between the transmission bowl 32 and the wheel hub 30 illustrated in figures 1 and 2 are equally applicable to all the embodiments for the drive wheels. More generally, the wheel hub 30 can be attached to the transmission bowl 32 by any suitable means, in particular the method described in patent application FR 3 003 201. It is also possible to provide the walls of the tubular space 47 of the wheel hub 30 and the corresponding parts of the projection 46 of the transmission bowl 32 with pre-machined splines.

[0074] Although the transmission joint 320 is shown as a Rzeppa type constant velocity joint controlled by rolling grooves 461, 321, it may be other variants of constant velocity joints, such as a Rzeppa joint controlled by a joint cage, or a cross track joint. Thus, the rolling grooves 461, 321 do not necessarily have to be circular, and do not necessarily have to be concave, but may have a straight track.

[0075] It is emphasized that all configurations that are apparent to a person skilled in the art from the present specification, the drawings and the appended claims, even if specifically described only in relation to other determined configurations, can be combined with other configurations or groups of configurations disclosed herein, either individually or in any combination, provided that this is not expressly excluded or that the technical circumstances do not make the combination impossible or meaningless.

[0076] Throughout the text of this specification, the term "fixed subassembly" has been used to refer to a subassembly that provides a fixed coordinate system for rotation of a moveable subassembly. Those skilled in the art will appreciate that the subassembly itself may be required to move relative to the vehicle body, depending on the geometry of the suspension system interposed between the vehicle body and the fixed subassembly. The present invention includes the following embodiments. [Aspect 1] A drive wheel assembly (10) for a motorized vehicle, comprising: a stationary subassembly (12) including a first annular outer ring raceway (22) and a second annular outer ring raceway (24) centered about a common axis of rotation (100); a rotating subassembly (14) rotatable relative to the fixed subassembly (12) about the axis of rotation (100) and having a wheel hub (30) including a flange (38) providing a mounting surface for a wheel rim (40) or a brake disc (41); The mounting flange (38) forms a mounting surface (42) axially oriented in a disassembly direction (200) of the wheel rim (40) or the brake disc (41), the disassembly direction (200) being parallel to the rotation axis (100), the mounting surface (42) being tangential to an assembly reference plane (PA) perpendicular to the rotation axis (100), a transmission bowl (32) and at least one inner ring portion (36), the inner ring portion (36) being a rotating subassembly (14) that is shrink-fitted into a shrink-fit bearing (52) of a wheel hub and supports against the transmission bowl (32) at annular contact surfaces (58, 60) that extend at least radially relative to the rotating shaft (100), the rotating subassembly including a first inner raceway surface (56) located opposite the first outer raceway surface (22) and a second inner raceway surface (62) formed on the inner ring portion (36) located opposite the second outer raceway surface (24); the rolling elements (16, 18) form a first rolling element row (16) capable of rolling on the first outer ring raceway (22) and the first inner ring raceway (56) and a second rolling element row (18) capable of rolling on the second outer raceway (24) and the second inner raceway (62), a first pitch plane (PP1) including a center of the first rolling element row (16) is located at a non-zero distance L from a second pitch plane (PP2) including a center of the second rolling element row (18), and in the disassembly direction (200), the first rolling element row (16) and the second rolling element row (18) have rolling elements (16, 18) that are in contact with the rolling elements of the second rolling element row (18) and are located on the same outer side of a boundary plane (PL) of the drive wheel assembly (10) perpendicular to the rotation axis (100); a contact surface (58, 60) between the inner ring portion (36) and an annular bearing surface (60) of the transmission bowl (32) is at least partially, preferably completely, disposed between the first pitch surface (PP1) and an interface surface (PL), and has a maximum contact diameter (DA) that is greater than a shrink-fit bearing diameter (DF) and is less than or equal to a raceway bottom diameter (DI2) of the second inner ring raceway surface (62). [Aspect 2] 2. The drive wheel assembly (10) according to claim 1, 1. A drive wheel assembly (10) characterized in that the annular contact surface (58, 60) between the inner ring portion (36) and the annular bearing surface (60) of the transmission bowl (32) is at least partially, preferably completely, disposed between the first pitch surface (PP1) and the second pitch surface (PP2). [Aspect 3] The drive wheel assembly (10) of claim 1 or 2, wherein the first outer ring raceway (22) has a raceway bottom diameter DE1 that is smaller than a raceway bottom diameter DI2 of the second inner ring raceway (62). Aspect 4 4. The drive wheel assembly (10) according to any one of the first to third aspects, wherein the transmission bowl (32) has a space (50) including a rolling groove (461), and the rolling groove (461) is preferably a groove bottom diameter DBO is greater than a raceway bottom diameter DI1 of the first inner ring raceway; a groove bottom diameter DBO is smaller than a raceway bottom diameter DI2 of the second inner ring raceway; The groove bottom diameter DBO is greater than the maximum contact diameter DA; A drive wheel assembly (10) having a groove bottom diameter DBO that satisfies one or more of the following conditions. Aspect 5 A drive wheel assembly (10) according to any one of aspects 1 to 4, characterized in that the rolling elements (16, 18) are balls, and the balls constituting the first rolling element row (16) have a ball diameter DC1 that is equal to or smaller than a ball diameter DC2 of the balls constituting the second rolling element row (18). Aspect 6 The drive wheel assembly (10) of claim 5, wherein the inner ring portion (36) has an end surface (57) facing an axial direction in the disassembly direction (200) and is located at a distance L1 from a plane (PAB) containing a point of the annular contact surface (58, 60) farthest from the rotation axis, and the distance L1 is less than 1.5 times the ball diameter DC1 of the first ball row (16). Aspect 7 7. The drive wheel assembly (10) according to claim 5 or 6, wherein a maximum contact diameter DA of the annular contact surface (58, 60) is smaller than the sum of twice the diameter DC1 of the first row of rolling elements (16) and a diameter DF of the shrink-fit bearing (52). Aspect 8 8. The drive wheel assembly (10) according to any one of the first to seventh aspects, further comprising a transmission nut (322) and rolling elements (323), the rolling elements (323) being guided by the rolling grooves (461, 321) formed in the space (50) of the transmission bowl (32) and in the transmission nut (322), the transmission nut (322), the rolling elements (323) and the transmission bowl (32) forming a transmission joint (320) defining a pitch plane (PPB) and a pitch diameter. Aspect 9 A drive wheel assembly (10) according to claim 8, characterized in that the maximum contact diameter DA of the annular contact surfaces (58, 60) is smaller than a pitch diameter DPB of the transmission joint. Aspect 10 10. The drive wheel assembly (10) according to claim 8 or 9, wherein a pitch plane (PPB) of the transmission joint (320) is located at a distance CA from an assembly datum plane (PA), and the distance CA is: the distance CA is smaller than the pitch diameter (DP2) of the second row of rolling elements (18); - said distance CA is less than 7 / 13 of the axial distance measured between said assembly reference plane (PA) and said second pitch plane (PP2); the ratio of said distance CA to the distance L between said first pitch plane (PP1) and said second pitch plane (PP2) is less than 4.75, preferably less than 4.6; the ratio of a difference between a distance CA between the assembly reference plane (PA) and the second pitch plane (PP2) and a distance L2 to a pitch diameter of the second row of rolling elements is less than 0.45; A drive wheel assembly (10) characterized by satisfying one or more of the following conditions. Aspect 11 11. The drive wheel assembly (10) according to any one of the preceding aspects, wherein the annular contact surfaces (58, 60) are planar. Aspect 12 12. The drive wheel assembly (10) according to any one of the preceding aspects, wherein the annular contact surface (58, 60) is flared, preferably tapered, and preferably has an apex angle A of: - apex angle A is between 100° and 140°; - apex angle A is equal to apex angle B of the frusto-conical inner surface of the transmission bowl (32) opposite the annular bearing surface (60) within the range of ±10°; A drive wheel assembly (10) characterized by satisfying one or more of the following conditions. Aspect 13 A drive wheel assembly (10) according to any one of the preceding aspects, comprising: A drive wheel assembly (10) characterized in that a ratio of a maximum contact diameter DA of the annular contact surfaces (58, 60) to a pitch diameter DP2 of the second row of rolling elements (18) is less than 0.65. Aspect 14 14. The drive wheel assembly (10) according to any one of claims 1 to 13, wherein the transmission bowl (32) includes a splined end (46) that is fitted or shrink fitted to a splined tubular portion (47) of the wheel hub (30) and forms a splined contact surface, and the rotating subassembly (14) preferably includes at least one axial retaining element (80, 88) that is attached to the transmission bowl (32) and supports, directly or indirectly, against an abutment surface (84) of the wheel hub (30) axially rotated in the disassembly direction (200). Aspect 15 A drive wheel assembly (10) as described in claim 14, characterized in that the splined contact surface has a spline pitch diameter DPC, and the annular contact surface (58, 60) is axially located at a distance LAB from an assembly reference plane PA such that the sum of DPC and LAB (DPC+LAB) is less than the pitch diameter DP2 of the second row of rolling elements. Aspect 16 The drive wheel assembly (10) according to aspect 14 or 15, wherein a distance (LPC) measured between an end of the spline contact surface closest to the annular contact surface (58, 60) in the axial direction and the assembly reference plane (PA) is less than four-fifths of a length L2 measured between the assembly reference plane (PA) and the second pitch surface (PP2). Aspect 17 A drive wheel assembly (10) according to any one of the preceding aspects, comprising: The drive wheel assembly (10) is characterized in that the wheel hub (30) is a one-piece metal component. Aspect 18 18. The drive wheel assembly (10) according to any one of the preceding aspects, wherein the metal portion of the rotating subassembly (14) further comprises the brake disc (41) attached to the mounting surface (42), the wheel rim (40) attached to the brake disc (41), and a mounting element (143) for mounting the wheel rim (40) and the brake disc (41) to a mounting flange (38).

Claims

1. A drive wheel assembly (10) for a motorized vehicle, comprising: a stationary subassembly (12) including a first annular outer ring raceway (22) and a second annular outer ring raceway (24) centered about a common axis of rotation (100); a rotating subassembly (14) rotatable relative to the fixed subassembly (12) about said axis of rotation (100) and having a wheel hub (30) including a flange (38) providing a mounting surface for a wheel rim (40) or a brake disc (41); The mounting flange (38) forms a mounting surface (42) oriented axially in a disassembly direction (200) of the wheel rim (40) or the brake disc (41), the disassembly direction (200) being parallel to the rotation axis (100), the mounting surface (42) being tangential to an assembly reference plane (PA) perpendicular to the rotation axis (100), and the transmission bowl (32) and at least one inner ring portion (36), the inner ring portion (36) being a rotating subassembly (14) that is shrink-fitted into a shrink-fit bearing (52) of a wheel hub and supports against the transmission bowl (32) at annular contact surfaces (58, 60) that extend at least radially relative to the rotational axis (100), the rotating subassembly including a first inner raceway surface (56) located opposite the first outer raceway surface (22) and a second inner raceway surface (62) formed on the inner ring portion (36) located opposite the second outer raceway surface (24); the rolling elements (16, 18) form a first rolling element row (16) capable of rolling on the first outer ring raceway surface (22) and the first inner ring raceway surface (56) and a second rolling element row (18) capable of rolling on the second outer ring raceway surface (24) and the second inner ring raceway surface (62), a first pitch plane (PP1) including a center of the first rolling element row (16) is located at a non-zero distance L from a second pitch plane (PP2) including a center of the second rolling element row (18), and in the disassembly direction (200), the first rolling element row (16) and the second rolling element row (18) have rolling elements (16, 18) tangent to the rolling elements of the second rolling element row (18) and located on the same outer side of a boundary plane (PL) of the drive wheel assembly (10) perpendicular to the rotation axis (100); 1. A drive wheel assembly for a motorized vehicle, comprising: a first pitch surface and an annular bearing surface of a transmission bowl, the first pitch surface being at least partially disposed between the first pitch surface and an interface surface ...

2. 2. A drive wheel assembly (10) according to claim 1, comprising:

1. A drive wheel assembly (10) comprising: a transmission bowl (32) having an annular contact surface (58, 60) between the inner race (36) and an annular bearing surface (60) of the transmission bowl (32), the annular contact surface (58, 60) being at least partially disposed between the first pitch surface (PP1) and the second pitch surface (PP2).

3. 3. The drive wheel assembly (10) of claim 1 or 2, wherein the first outer ring raceway (22) has a raceway bottom diameter DE1 that is smaller than a raceway bottom diameter DI2 of the second inner ring raceway (62).

4. 4. A drive wheel assembly (10) according to any one of claims 1 to 3, wherein the transmission bowl (32) has a space (50) including a rolling groove (461), the rolling groove (461) being: the groove bottom diameter DBO is greater than the raceway bottom diameter DI1 of the first inner ring raceway; the groove bottom diameter DBO is smaller than the raceway bottom diameter DI2 of the second inner ring raceway; the groove bottom diameter DBO is greater than said maximum contact diameter DA; A drive wheel assembly (10) having a groove bottom diameter DBO that satisfies one or more of the following conditions.

5. 5. A drive wheel assembly (10) according to claim 1, wherein the rolling elements (16, 18) are balls, and the balls constituting the first row of rolling elements (16) have a ball diameter DC1 that is equal to or smaller than a ball diameter DC2 of the balls constituting the second row of rolling elements (18).

6. 6. The drive wheel assembly (10) of claim 5, wherein the inner ring portion (36) has an end face (57) facing an axial direction in a disassembly direction (200) and is located at a distance L1 from a plane (PAB) containing a point of the annular contact surface (58, 60) farthest from the axis of rotation, and the distance L1 is less than 1.5 times a ball diameter DC1 of the first row of balls (16).

7. 7. The drive wheel assembly (10) according to claim 5 or 6, characterized in that a maximum contact diameter DA of the annular contact surface (58, 60) is smaller than the sum of twice the diameter DC1 of the first row of rolling elements (16) and a diameter DF of the shrink-fit bearing (52).

8. 8. The drive wheel assembly (10) according to claim 1, further comprising a transmission nut (322) and rolling elements (323), the rolling elements (323) being guided by rolling grooves (461, 321) formed in a space (50) of the transmission bowl (32) and in the transmission nut (322), the transmission nut (322), the rolling elements (323) and the transmission bowl (32) forming a transmission joint (320) defining a pitch plane (PPB) and a pitch diameter.

9. 9. The drive wheel assembly (10) of claim 8, wherein the maximum contact diameter DA of the annular contact surfaces (58, 60) is smaller than a pitch diameter DPB of the transmission joint.

10. 10. A drive wheel assembly (10) according to claim 8 or 9, wherein the pitch plane (PPB) of the transmission joint (320) is located at a distance CA from an assembly reference plane (PA), said distance CA being: said distance CA is smaller than the pitch diameter (DP2) of the second row of rolling elements (18); - said distance CA is less than 13 / 7 of the axial distance measured between said assembly reference plane (PA) and said second pitch plane (PP2); the ratio of said distance CA to the distance L between said first pitch plane (PP1) and said second pitch plane (PP2) is less than 4.75; the ratio of the difference between the distance CA between the assembly reference plane (PA) and the second pitch plane (PP2) and the distance L2 to the pitch diameter of the second row of rolling elements is less than 0.45; A drive wheel assembly (10) characterized by satisfying one or more of the following conditions.

11. A drive wheel assembly (10) according to any one of the preceding claims, characterized in that the annular contact surface (58, 60) is flat.

12. 11. A drive wheel assembly (10) according to any one of claims 1 to 10, wherein the annular contact surface (58, 60) is frusto-conical in shape, with an apex angle A of: - the apex angle A is between 100° and 140°, - apex angle A is equal to apex angle B of the frusto-conical inner surface of said transmission bowl (32) opposite said annular bearing surface (60) in the range of ±10°; A drive wheel assembly (10) characterized by satisfying one or more of the following conditions.

13. A drive wheel assembly (10) according to any one of claims 1 to 12, comprising: A drive wheel assembly (10), characterized in that the ratio of a maximum contact diameter DA of the annular contact surface (58, 60) to a pitch diameter DP2 of the second row of rolling elements (18) is less than 0.

65.

14. 14. The drive wheel assembly (10) according to any one of claims 1 to 13, wherein the transmission bowl (32) includes a splined end (46) that is fitted or shrink-fitted to a splined tubular portion (47) of the wheel hub (30) and forms a splined contact surface, and the rotating subassembly (14) includes at least one axial retaining element (80, 88) that is attached to the transmission bowl (32) and supports, directly or indirectly, against an abutment surface (84) of the wheel hub (30) axially rotated in the disassembly direction (200).

15. 15. The drive wheel assembly (10) of claim 14, wherein the splined contact surface has a spline pitch diameter DPC, and the annular contact surface (58, 60) is axially located a distance LAB from an assembly reference plane PA such that the sum of DPC and LAB (DPC+LAB) is less than a pitch diameter DP2 of the second row of rolling elements.

16. 16. The drive wheel assembly (10) according to claim 14 or 15, characterized in that a distance (LPC) measured between an end of the spline contact surface closest to the annular contact surface (58, 60) in the axial direction and the assembly reference plane (PA) is less than four-fifths of a length L2 measured between the assembly reference plane (PA) and the second pitch surface (PP2).

17. A drive wheel assembly (10) according to any one of claims 1 to 16, The drive wheel assembly (10) is characterized in that the wheel hub (30) is a one-piece metal part.

18. 18. A drive wheel assembly (10) as claimed in any one of claims 1 to 17, characterized in that the rotating sub-assembly (14) further comprises the brake disc (41) mounted on the mounting surface (42), the wheel rim (40) mounted on the brake disc (41), and a mounting element (143) for mounting the wheel rim (40) and the brake disc (41) to a mounting flange (38).

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