Rotating assembly, in particular for guiding the wheels of a motorized vehicle - Patent Application 20070122997

Abstract

An axially compacted rotating assembly is provided, particularly for guiding the wheels of a motorized vehicle. [Solution] A drive wheel assembly (10) for a motorized vehicle is composed of a fixed subassembly (12) including two outer ring raceways (22, 24), a first inner ring portion (30, 34) arranged on two pitch planes PP1 and PP2, and a rotating subassembly (14) including a second inner ring portion (36) and two rows of balls (16, 18). The second inner ring portion (36) is located between the first pitch plane (PP1) and the second pitch plane (PP2) in a cross-sectional plane (PC) perpendicular to the rotation axis (100), and has an outer diameter (Φ) measured at a measurement distance DM from the first pitch plane (PP1) that is greater than a predetermined threshold value VS.

Description

[Technical Field]

[0001] The present invention relates to a rotating assembly, and in particular to a rotating assembly suitable for guiding the wheels, especially the drive wheels, of 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 vehicle's suspension elements and including first and second outer raceways defining a rotation axis, and a rotating assembly, rotatable relative to the fixed elements about the rotation axis, including 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 balls, with a first row of balls formed between the first outer raceway and the first inner raceway, and a second row of balls formed between the second outer raceway and the second inner raceway. The wheel hub has mounting surfaces for the wheel rim and brake disc. This assembly typically consists of a stack of technical functions—torque transmission, mounting to the vehicle suspension, rotational guidance, braking, and rolling—distributed along the rotation axis from the inside to the outside of the vehicle, which requires a large dimension in the axial direction, i.e., transversely in the vehicle's coordinate system.

[0003] Patent Document 1 proposes shrink-fitting the inner ring of the second raceway into the transmission bowl, which reduces the axial size for a given distance between the two rows of balls while allowing the pitch diameter of the row of balls 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 balls and the pitch diameter of the ball row, this structure provides a solution for achieving both reduced 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] Electric and hybrid vehicle powertrains often have larger drive wheels across the vehicle than internal combustion engine powertrains, which can result in shorter lateral drive shafts. A shorter drive shaft is undesirable because it increases the deflection angle of the transmission joint as the wheels move relative to the chassis. Therefore, any slight increase in space available for locating the transmission shaft is considered desirable. This increases the need for axially compact drive wheel assemblies without sacrificing performance, particularly load capacity and stiffness.

[0006] The present invention aims to provide a rotating assembly, for example for guiding the drive wheels of a motorized vehicle, that 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 present invention, 1. A rotating assembly comprising: an outer subassembly including a first annular outer ring raceway and a second annular outer ring raceway about a common axis of rotation; an inner subassembly including a first inner ring portion and a second inner ring portion, wherein the first inner ring portion, on which a first inner ring raceway surface is formed, has a raceway bottom diameter DI1, and the second inner ring portion, on which a second inner ring raceway surface is formed, has a raceway bottom diameter DI2 that is larger than the raceway bottom diameter DI1 of the first inner ring raceway surface, and the second inner ring portion and the first inner ring portion are fixed relative to each other; A rotating assembly is proposed, comprising balls, the balls forming a first row of balls rollable on the first outer ring raceway surface and the first inner ring raceway surface and a second row of balls rollable on the second outer ring raceway surface and the second inner ring raceway surface in order to relatively guide the outer sub-assembly and the inner sub-assembly which rotate about the rotation axis, the first row of balls having a diameter DC1, and a first pitch plane including the centers of the balls in the first row being arranged at a non-zero distance L from a second pitch plane including the centers of the balls in the second row.

[0008] According to the present invention, the second inner ring portion is located between the first pitch surface and the second pitch surface in a cross-sectional plane perpendicular to the rotation axis, and has an outer diameter (Φ) that is greater than a predetermined threshold value VS when measured at a measurement distance DM from the first pitch surface, where the following equation holds:

number

[0009] These dimensional characteristics reflect the fact that the second inner ring portion supporting the second inner ring raceway is located near the first raceway surface and has a substantial thickness near the first raceway surface, providing high rigidity to the inner subassembly and sufficient axial compactness to the rotating assembly.

[0010] Preferably, the second inner ring portion has an axial end face axially facing the first pitch surface and axially supporting the bearing surface of the first inner ring portion. The axial end face is located at a distance D from the first pitch surface, preferably less than half the diameter DC1 of the first row of balls, in a cross section located between the first pitch surface and the second pitch surface. Preferably, the axial end face is planar. The axial end face preferably has an outer diameter equal to or substantially equal to the diameter of the bearing surface. The outer diameter of the axial end face is preferably equal to or greater than the raceway bottom diameter DI1. In practice, the outer diameter of the axial end face is equal to or less than a threshold value VS. In a cross section taken along a plane including the rotation axis, the outer peripheral surface of the second inner ring portion at a portion located between the axial end face and the cross-sectional plane PC is concave, and the distance from the current point of the outer peripheral surface of the second inner ring portion to the rotation axis continuously increases as the current point moves away from the axial end face and approaches the cross-sectional plane PC.

[0011] To facilitate positioning of the first row of balls during installation or use of the assembly, a first one-piece bearing retainer is preferably provided, the first one-piece bearing retainer including a cylindrical portion defining a reference axis of the first bearing retainer and retaining claws located on the outer periphery of the pockets to define housing cells for the first row of balls.

[0012] The second inner ring occupies a space near the first raceway, leaving little space for the cylindrical portion of the cage to accommodate the cage located between the first and second pitch surfaces. Therefore, preferably, the cylindrical portion is disposed on one side of the first pitch surface opposite the second pitch surface, the claws protrude from the cylindrical portion across the first pitch surface toward the second pitch surface, and the claws have free distal ends, and each pocket is bounded by two adjacent claws of the first one-piece cage and a portion of the cylindrical portion connecting the two adjacent claws. The first cage does not have a cylindrical portion located between the first and second pitch surfaces near the second inner ring. To allocate more space for the second inner ring, its outer diameter can be increased in the region between the axial end face and the cross-sectional plane PC.

[0013] Preferably, the pockets are of the encircling type, and the pawls encircle the balls to prevent them from escaping during assembly. According to one embodiment, for each pocket, two adjacent pawls each have a concave guide surface facing the balls accommodated in the pocket, and the guide surface is preferably at least partially located inside a first pitch cylinder that passes through the centers of the first row of balls and has a first pitch circle centered on the rotation axis as its base, and preferably is at least partially located between the first pitch surface and the second pitch surface. Preferably, the cylindrical portion connecting the two adjacent pawls includes a guide end surface facing the balls accommodated in the pocket, and the guide end surface is preferably located at least partially radially outside the first pitch cylinder.

[0014] According to a first variant, the first bearing cage further comprises additional pawls arranged on the outer periphery of the cylindrical portion, each additional pawl being associated with one pawl and having a free distal end 86 located radially outside and opposite the associated pawl 74. Preferably, for each pocket, the two additional pawls associated with two adjacent pawls each include an additional concave guide surface facing the ball accommodated in the pocket, the additional guide surface being arranged at least partially outside the first pitch cylinder and at least partially between the first pitch surface and the second pitch surface.

[0015] According to a second variant, for each pocket, two adjacent pawls each include an additional concave guide surface facing the ball accommodated in the pocket, the additional guide surface being arranged at least partially outside the first pitch cylinder and at least partially between the first and second pitch surfaces.

[0016] It is advantageous to provide a means for stacking and storing cages on an assembly line before installing the drive wheel assemblies. For this purpose, it is possible to specify that the cylindrical portion of the first bearing cage has a planar lamination surface facing axially away from the pawls and a centering bearing rotationally symmetrical with respect to the reference axis of the first bearing cage, and that the first bearing cage further has a centering surface that includes a planar facet facing axially away from the annular lamination surface, the planar facet overlapping the planar lamination surface when viewed in orthogonal projection in the lamination plane including the planar lamination surface, and that is radially inverted to face the centering bearing when viewed in orthogonal projection in the lamination plane, with the centering surface and the centering bearing facing the annular lamination surface. This allows the cages to be stacked while maintaining their centers without the risk of them adhering to each other.

[0017] To provide good positioning of the second row of balls during installation or use of the assembly, the second one-piece bearing cage preferably comprises a cylindrical portion defining a reference axis of the second bearing cage and pawls distributed around the periphery of the cylindrical portion of the second bearing cage to define pockets for receiving the second row of balls.

[0018] The second inner and outer rings occupy the space between the first and second pitch surfaces and near the second raceway surface, leaving little space for the cylindrical portion of the cage to accommodate the cage located between the first and second pitch surfaces. Therefore, preferably, the cylindrical portion of the second bearing cage is disposed on the second pitch surface side opposite the first pitch surface, the claws of the second bearing cage protrude from the cylindrical portion of the second bearing cage across the second pitch surface toward the first pitch surface, the claws of the second bearing cage have free distal ends, and each pocket is defined by a portion of the cylindrical portion connecting two adjacent claws of the second bearing cage to two adjacent claws. The second cage does not have a cylindrical portion located between the first and second pitch surfaces. Therefore, a space can be secured between the first pitch surface and the second pitch surface for increasing the outer diameter of the second inner ring portion and decreasing the inner diameter of the outer ring portion.

[0019] According to a particularly advantageous embodiment, the ball diameter DC1 of the balls constituting the first row of balls is equal to or less than the ball diameter DC2 of the balls constituting the second row of balls. The larger diameter of the balls in the second row allows the distance between the two rows of balls to be reduced, limiting flexing in the second inner ring section and therefore the risk of separation of the parts of the inner subassembly. The outer ring raceways are preferably axially enclosed, in the sense that they each have a raceway base located axially midway between the axial ends of the raceway.

[0020] According to one embodiment, the second inner ring is shrink fitted to a shrink-fit bearing of the first inner ring. Alternatively, the first and second inner rings can be shrink fitted to a common solid or hollow part.

[0021] The second inner ring is preferably a solid metal part, for example made from steel.Similarly, the first inner ring is preferably a solid metal part, for example made from steel.

[0022] The rotating assembly as described above is particularly suitable for guiding vehicle wheels, in particular drive wheels. According to one embodiment, the outer subassembly constitutes a fixed subassembly for guiding a drive wheel of a motorized vehicle, and the inner subassembly constitutes a rotating subassembly for guiding a drive wheel of a motorized vehicle, rotatable about a rotation axis relative to the fixed subassembly, the rotating subassembly comprising a wheel hub consisting of a flange having a mounting surface for mounting a wheel rim or a brake disc, the mounting flange forming a mounting surface for the wheel rim or the brake disc facing an axial direction in a disassembly direction of the wheel rim or the brake disc, the disassembly direction being parallel to the rotation axis, the first inner ring portion being formed by the wheel hub or being shrink-fitted to the wheel hub, and the second inner ring portion being shrink-fitted to a shrink-fit bearing of the wheel hub.

[0023] The first raceway and the first row of balls are intended to be farther from a vertical plane at the longitudinal center of the vehicle than the second raceway and the second row of balls when the assembly is installed in the vehicle.

[0024] According to one embodiment, the rotating subassembly further comprises a transmission bowl, and the inner ring supports the transmission bowl with an annular contact surface extending at least radially relative to the rotation axis. Preferably, the annular contact surface is at least partially, preferably completely, disposed between the first pitch surface and the second pitch surface, which contributes significantly to the compactness of the rotating assembly.

[0025] The second inner ring portion has a particular shape that allows the second inner ring raceway to be positioned radially outward of the first inner ring raceway, and allows a recess formed by the inner ring portion to accommodate a portion of the transmission bowl, including the annular bearing surface.

[0026] Preferably, the wheel hub is a solid, one-piece metal part, which contributes to the rigidity of the assembly, or the hub can be a solid, one-piece multi-material part, such as a steel / aluminum or steel / composite combination, for example.

[0027] Where appropriate, the rotating subassembly further comprises a brake disc bearing on the mounting surface, a wheel rim bearing on the brake disc, and components for mounting the wheel rim and brake disc to the mounting flange. [Brief explanation of the drawings]

[0028] 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. [Figure 1] 1 is a longitudinal cross-sectional view showing a rotation assembly for guiding drive wheels of a motorized vehicle according to a first embodiment of the present invention. [Figure 2] FIG. 2 is an isometric view of a bearing cage of the rotating assembly of FIG. 1. [Figure 3] 3 shows two bearing retainers similar to that of FIG. 2 stacked on top of each other before one is attached to the assembly of FIG. 1. [Figure 4] FIG. 6 is a longitudinal cross-sectional view showing a rotation assembly for guiding drive wheels of a motorized vehicle according to a second embodiment of the present invention. [Figure 5] 1 or 4 for a rotating assembly according to FIG. 2 in an isometric view. [Figure 6] 6 shows two bearing retainers similar to that of FIG. 5 stacked on top of each other before one is attached to the assembly of FIG. 1 or FIG. 4. [Figure 7] 1 or 4 for a rotating assembly according to FIG. 2 in an isometric view. [Figure 8] 8 shows two bearing retainers similar to that of FIG. 7 stacked on top of each other before one is attached to the assembly of FIG. 1 or FIG. 4. [Figure 9] 1 or 4 for a rotating assembly according to FIG. 2 in an isometric view. [Figure 10] 10 shows two bearing retainers similar to that of FIG. 9 stacked on top of each other before one is attached to the assembly of FIG. 1 or FIG. 4. DETAILED DESCRIPTION OF THE INVENTION

[0029] For greater clarity, identical or similar elements are provided with the same reference numerals in all figures.

[0030] FIG. 1 shows a rotating assembly for guiding a drive wheel 10 of a motorized vehicle, which is intended to be fixed to a suspension member (not shown) of the motorized vehicle and includes a fixed outer subassembly 12 defining a rotation axis 100, an inner rotating subassembly 14 rotatable about the rotation axis 100 inside the fixed outer subassembly 12, and balls 16, 18 between the rotating subassembly 14 and the fixed subassembly 12.

[0031] Here, the fixed outer subassembly 12 is comprised of a one-piece solid metal outer ring section 20 having formed thereon coaxial first and second outer ring raceways 22, 24 that define an axis of rotation 100. The outer ring section 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).

[0032] The inner rotating subassembly 14 is comprised of a wheel hub 30, a transmission bowl 32, and an optional first inner ring portion 34 and a second inner ring portion 36.

[0033] The wheel hub 30 is a one-piece metal part consisting of a wheel rim 40 and a flange 38 for mounting a brake disc 41. The flange 38 has a surface 42 for supporting the brake disc 41 and is provided with mounting holes 43 that allow the insertion of mounting elements 143 for the rim 40 and the brake disc 41.

[0034] The wheel hub 30 also has a centering skirt 44 that projects axially relative to the planar bearing surface 42, in the disassembly direction 200 of the wheel rim 40 and brake disc 41, and is provided with a radially outwardly facing centering bearing 45 (preferably stepped) consisting of a first cylindrical portion for centering the wheel rim 40 and a second cylindrical portion of the same diameter or larger 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 brake disc 41 after assembly.

[0035] Transmission bowl 32 is a solid, one-piece metal part having a protruding end portion 46 and a flared intermediate portion 48 that defines constant velocity joint space 50. Protruding portion 46 of transmission bowl 32 is preferably splined and freely mounted within a splined tubular space 47 of wheel hub 30, either mated or shrink-fit to form a splined contact surface. Additionally, Figure 1 shows a means for attaching transmission bowl 32 to wheel hub 30, such as a nut 188 that threads onto a threaded end 190 of protruding portion 46 and supports shoulder 84 of wheel hub 30.

[0036] The first inner ring portion 34 is shrink-fitted into a cylindrical shrink-fit bearing 52 on the wheel hub 30 and is axially supported against an annular shoulder 54 formed on the wheel hub 30. A first inner ring raceway surface 56 is formed on the first inner ring portion 34 facing the first outer ring raceway surface 22.

[0037] The second inner ring portion 36 is also shrink-fitted into the cylindrical shrink-fit bearing 52 of the wheel hub 30, with its lateral end faces 57 axially supporting against the lateral faces 59 of the first inner ring portion 34. The second inner ring portion 36 has an annular abutment surface 58, here frustoconical but which may be flat, that projects axially away from the first inner ring raceway 56 and supports an annular bearing surface 60 formed on the transmission bowl 32. A second inner ring raceway 62 is formed on the second inner ring portion 36 opposite the second outer ring raceway 24. The balls 16, 18 form a first ball row 16 that rolls on the first outer ring raceway 22 and the first inner ring raceway 56, and a second ball row 18 that rolls on the second outer ring raceway 24 and the second inner ring raceway 62, on the other hand.

[0038] The remainder of this discussion will focus on salient dimensional characteristics of the assembly, which require some preliminary definitions. Therefore, we define them as follows: PP1: the pitch plane on which the pitch circle constituting the locus of the centers of the first row of balls 16 having the reference dimensions is located. PP2: the pitch plane on which the pitch circle constituting the locus of the centers of the second row of balls 18 having the reference dimensions is located. DP1: the pitch diameter of the first row of balls 16. DP2: Pitch diameter of the balls 18 in the second row. -CP1: A pitch cylinder whose center is the rotation axis 100 and whose base is the pitch circle of the first row of balls 16. DC1: diameter of the balls 16 in the first row. DC2: diameter of the balls 18 in the second row. -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 surface 62, and is defined as the minimum diameter of the inner ring raceway surface 62. DE1: raceway bottom diameter of the first outer ring raceway surface 22, and is defined as the maximum diameter of the outer ring raceway surface 22. -PB: A surface that is perpendicular to the rotation axis 100 and that is in contact with the axial end face 57 of the second inner ring portion 36. -D: the distance between the plane PB and the first pitch surface PP1.

[0039] The first pitch plane PP1 is located at a non-zero distance L from the second pitch plane PP2. It is noteworthy that the raceway bottom diameter DI2 of the second inner raceway surface 62 is larger than the raceway bottom diameter DI1 of the first inner raceway surface 56 and is preferably larger than the raceway bottom diameter DE1 of the first outer raceway surface 22. Therefore, the second inner raceway portion 36 has a flared shape that widens in the direction opposite to the disassembly direction from the axial end face 57, allowing a portion of the transmission bowl 32 to be accommodated within the second inner raceway portion 36. The second inner raceway portion 36 is accommodated in the tight space between the outer raceway portion 20 and the transmission bowl 32, which has a generally frustoconical contour. To provide high rigidity to the second inner raceway portion 36, the outer diameter of the inner raceway portion 36, measured radially relative to the rotation axis 100, is specified to rapidly increase with increasing distance from the axial end face 57.

[0040] This diametric increase can be characterized by measuring the outer diameter Φ of the second inner ring portion 36 at a cross-sectional plane PC perpendicular to the rotation axis 100 and located between the first pitch plane PP1 and the second pitch plane PP2, a measurement distance DM from the first pitch plane PP1, as follows:

number

[0041] Characteristically, the outer diameter Φ is greater than a threshold value VS that is equal to the larger of two values: 110% of the raceway bottom diameter DI1 of the first inner ring raceway surface 56; and the sum of the raceway bottom diameter DI1 of the first inner ring raceway surface 56 and the radius of the first row of balls 16.

number

[0042] The plane PB, in which the contact surface between the axial end face 57 and the annular bearing surface 59 lies, is preferably located between the first pitch plane PP1 and the second pitch plane PP2, at a distance D from the first pitch plane PP1 that is preferably less than half the diameter DC1 of the first row of balls 16. This positioning contributes to considerable axial compactness and excellent rigidity of the assembly 10.

[0043] The first row of balls 16 are guided in the space between the first inner ring raceway surface and the first outer ring raceway surface by a first one-piece bearing cage 70, shown in detail in Figure 2, which is composed of a cylindrical portion 72 that defines a reference axis 300 of the first cage 70, and pawls 74 arranged around the cylindrical portion 72 and that define pockets 76 for accommodating the first row of balls 16. The reference axis 300 of the first bearing cage 70 is intended to coincide with the rotation axis 100 when the rotating assembly 10 is in the reference position.

[0044] The rapid increase in the outer diameter of the second inner ring portion 36 near the first inner ring raceway 56 reduces the volume available for accommodating the first bearing cage 70. To maximize the volume available for the second inner ring portion 36 in the space between the first pitch plane PP1 and the second pitch plane PP2, it is advantageous to specify that the cylindrical portion 72 of the first bearing cage be positioned on the side of the first pitch plane PP1 opposite the second pitch plane PP2. The claws 74 extend from the cylindrical portion toward the second pitch plane PP2, crossing the first pitch plane PP1. Therefore, because the first cage does not have a cylindrical portion located between the first pitch plane PP1 and the second pitch plane PP2, the claws 74 have free distal ends 78. Each pocket 76 is defined by two adjacent claws 74 of the first bearing cage 70 and a portion of the cylindrical portion 72 connecting the adjacent two claws 74.

[0045] For each pocket 76, two adjacent claws 74 each form a concave guide surface 80 facing the ball 16 accommodated in the pocket 76, and a cylindrical portion 721 connecting two adjacent claws 74 forms an end guide surface 82 facing the ball 16 accommodated in the pocket. The end guide surface 82 has a base that is the pitch circle of the first row of balls 16 and is at least partially radially disposed outside the first pitch cylinder CP1 centered on the rotation axis 100. At least a portion of the guide surface 80 is located inside the first pitch cylinder CP1, and at least a portion is located between the first pitch surface PP1 and the second pitch surface PP2.

[0046] In this embodiment, the first bearing cage 70 further includes additional pawls 84 arranged on the outer periphery of the cylindrical portion 72. Each additional pawl 84 is associated with one of the pawls 74 and has a free distal end 86 located radially outward and opposite the associated pawl 74. For each pocket, the two additional pawls 84 associated with two adjacent pawls 74 each include an additional concave guide surface 88 facing the ball 16 accommodated in the pocket 76. The additional guide surfaces 88 are located at least partially outside the first pitch cylinder CP1 and at least partially between the first pitch surface PP1 and the second pitch surface PP2. In this manner, the surrounding cage 70 is manufactured so that the ball 16 cannot be inserted into the pocket and can only be removed from the cage by simultaneously elastically deforming the pawls 74, the additional pawls 84, or both the pawls 74 and the additional pawls 84. Therefore, there is no risk of losing the ball during assembly.

[0047] The cylindrical portion 72 of the first bearing cage 70 is composed of a planar annular lamination surface 722 facing axially away from the pawls 74 and a centering bearing 724 that is rotationally symmetric about the reference axis 300 of the first bearing cage 70. The free ends 86 of the additional pawls 84 face axially away from the planar annular lamination surface 722 and overlap in an orthogonal projection onto the lamination plane that includes the planar annular lamination surface 722. The pawls 74, in turn, include a centering bearing 724 and a centering surface 742 facing radially away from them, such that in an orthogonal projection onto the lamination plane, the centering surface 742 faces the centering bearing 724. Therefore, as shown in Figures 3 and 6, when two bearing retainers identical to the first integral bearing retainer 70 are stacked on top of each other before being attached to the rotating assembly 10, the free ends 86 of the additional claws 84 of the bearing retainer 70 abut against the annular stacking surface 722 of the adjacent bearing retainer 70, while the centering surface 742 faces the centering bearing 724, thereby ensuring a controlled relative positional relationship between the two bearing retainers 70 and preventing them from becoming closely intertwined.

[0048] The second row of balls 18 are guided in the space between the second inner ring raceway surface 62 and the second outer ring raceway surface 24 by a second one-piece bearing retainer 90 having a cylindrical portion 92 that defines a reference axis of the second retainer and pawls 94 arranged on the outer periphery of the cylindrical portion 92 and that define pockets for accommodating the second row of balls 18.

[0049] To maximize the volume available to the second inner ring 36 and the outer ring 20 in the space between the first pitch plane PP1 and the second pitch plane PP2, the cylindrical portion 92 is preferably positioned on the side of the second pitch plane PP2 opposite the first pitch plane PP1. The claws 94 protrude from the cylindrical portion toward the first pitch plane PP1, crossing the second pitch plane PP2. The claws 94 have free distal ends 98, and each pocket is defined by two adjacent claws 94 of the second bearing cage 90 and a portion of the cylindrical portion 92 connecting the adjacent two claws 94. The second bearing cage 90 has essentially the same configuration as the first bearing cage 70, and naturally has dimensions adapted to the diameter of the balls 18 and the pitch diameter of the second row of balls 18.

[0050] The outer ring raceways 22, 24 formed on the outer ring portion 20 are axially enclosed in the sense that they have raceway bottoms 64, 66 located midway between the axial ends of the corresponding raceway surfaces 22, 24, respectively.

[0051] In this embodiment, the diameter DC1 of the balls forming the first row of balls 16 is preferably equal to or less than the diameter DC2 of the balls forming the second row of balls 18. Selecting a relatively small diameter for the first row of balls 16 allows the axial thickness of the second inner ring portion 36 to be sufficient to bring the pitch surfaces PP1 and PP2 together in the shrink-fit region of the wheel hub 30 near the first row of balls 16. Selecting a large diameter for the second row of balls 18 allows the distance between the two pitch surfaces PP1, PP2 to be kept relatively small while still ensuring good load-bearing capacity.

[0052] 4 differs from the embodiment of FIG. 1 in that first inner ring raceway 56 is formed directly on wheel hub 30, i.e., forms first inner ring portion 34 and has shrink-fit bearing 52 and shoulder 159. Therefore, second inner ring portion 36 is shrink-fitted to shrink-fit bearing 52 and is axially supported against shoulder 159 of wheel hub 30 and against annular bearing surface 60 of transmission bowl 32.

[0053] 5 to 6 show a variant of the first bearing cage 70 intended to comprise a rotating assembly for guiding the drive wheels of the motorized vehicle 10 of FIG. 1 or 4. The first bearing cage 70 of FIGS. 5 and 6 differs from the variants described above in particular by the positioning of the first stacking surface 722, which is rearward relative to the axial end of the cylindrical portion 72 of the bearing cage 70, and by the positioning and centering surface 742 formed on the additional claws 84. FIG. 6 in particular shows the combination between the centering surface 742 and the centering bearing 724, and between the free ends 86 of the additional claws 84 and the annular stacking surface 722, in order to enable the first bearing cages 70 to be stacked on top of each other on the assembly line of the rotating assembly 10.

[0054] 7 to 8 show another variant of a first bearing cage 70 intended to comprise the rotating assembly 10 for guiding the drive wheels of the motorized vehicle of FIG. 1 or 4. The first bearing cage 70 of FIGS. 7 and 8 differs from conventional bearing cages in that it consists of only one set of claws 74 and does not have any additional claws. The claws 74 have guide surfaces 80 intended to be located at least partially inside the first pitch cylinder CP1 and at least partially between the first pitch plane PP1 and the second pitch plane PP2, and additional guide surfaces 88 intended to be located at least partially outside the first pitch cylinder CP1 and at least partially between the first pitch plane PP1 and the second pitch plane PP2. The encircling cage 70 is manufactured in the sense that the balls 16 cannot be inserted into the pockets but can only be removed from them by elastically deforming the claws 74. In the embodiment of FIGS. 5-8, the balls 16 are mounted in the first surrounding cage 70 with a motion that has either zero radial component or a radial component towards the reference axis 300.

[0055] 9 and 10 show another variant of a first bearing cage 70 intended to comprise the rotating assembly 10 for guiding the motorized vehicle of FIG. 1 or 4. The first bearing cage 70 of FIGS. 9 and 10 differs from conventional bearing cages in that it comprises only a pair of hook-shaped claws 74 and no additional claws. The claws 74 have a guide surface 80 intended to be located at least partially inside the first pitch cylinder CP1 and at least partially between the first pitch plane PP1 and the second pitch plane PP2, and an additional guide surface 88 intended to be located at least partially outside the first pitch cylinder CP1 and at least partially between the first pitch plane PP1 and the second pitch plane PP2. The encircling cage 70 is manufactured in the sense that the balls 16 cannot be inserted into the pockets but can only be removed from them by elastically deforming the claws 74. This embodiment of the first surrounding cage 70 also differs from the previously described cages in that the balls 16 are attached to the surrounding cage 70 by a motion having a radial component from the inside to the outside of the surrounding cage 70.

[0056] In all embodiments, the second bearing retainer 90 may be similar to the first bearing retainer 70 .

[0057] Alternatively, the two rows of balls 16, 18 may have the same diameter.

[0058] Alternatively, it is possible to provide a multi-part fixing subassembly comprising 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 within the clamp.

[0059] It is emphasized that all features 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 connection with other determined features, can be combined with other features or groups of features 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 sensible.

[0060] 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 movable 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 rotating assembly (10) comprising: an outer 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); an inner subassembly (14) including a first inner ring portion (30, 34) and a second inner ring portion (36), wherein the first inner ring portion (30, 34) on which a first inner ring raceway surface (56) is formed has a raceway bottom diameter DI1, and the second inner ring portion (36) on which a second inner ring raceway surface (62) is formed has a raceway bottom diameter DI2 that is larger than the raceway bottom diameter DI1 of the first inner ring raceway surface (56), and the second inner ring portion (36) and the first inner ring portion (30, 34) are fixed relative to each other; and balls (16, 18) that form a first row of balls (16) rollable on the first outer ring raceway surface (22) and the first inner ring raceway surface (56) and a second row of balls (18) rollable on the second outer ring raceway surface (24) and the second inner ring raceway surface (62) to relatively guide the outer subassembly (12) and the inner subassembly (14) that rotate about the rotation axis (100), the first row of balls (16) having a diameter DC1, and a first pitch plane (PP1) including the centers of the first row of balls (16) being disposed at a non-zero distance L from a second pitch plane (PP2) including the centers of the second row of balls (18), The second inner ring portion (36) is located between the first pitch plane (PP1) and the second pitch plane (PP2) in a cross-sectional plane (PC) perpendicular to the rotation axis (100), and has an outer diameter (Φ) measured at a measurement distance DM from the first pitch plane (PP1) that is greater than a predetermined threshold value VS, and the following formula is satisfied: [Number 1] TIFF0007719782000004.tif19149 [Aspect 2] 1. A rotating assembly according to claim 1, wherein the second inner ring portion includes an axial end surface that faces axially toward the first pitch surface and supports axially against a bearing surface of the first inner ring portion, the axial end surface being disposed at a distance D from the first pitch surface, preferably less than half the diameter DC of the first row of balls, in a transverse plane located between the first pitch surface and the second pitch surface. Aspect 3 A rotating assembly (10) according to aspect 1 or 2, further comprising a first one-piece bearing retainer (70), characterized in that the first one-piece bearing retainer (70) comprises a cylindrical portion (72) defining a reference axis (300) of the first bearing retainer (70) and pawls (74) distributed around the periphery of the cylindrical portion (72) to define pockets (76) for accommodating the first row of balls (16). Aspect 4 A rotating assembly (10) according to aspect 3, characterized in that the cylindrical portion (72) is arranged on one side of the first pitch surface (PP1) opposite the second pitch surface (PP2), the claws (74) protrude from the cylindrical portion (72) across the first pitch surface (PP1) toward the second pitch surface (PP2), the claws (74) have free distal ends (78), and each of the pockets (76) is bounded by two adjacent claws (74) of the claws (74) of the first one-piece retainer (70) and a portion of the cylindrical portion (721) connecting the two adjacent claws (74). Aspect 5 A rotating assembly (10) according to aspect 4, wherein for each pocket (76), the two adjacent pawls (74) each have a concave guide surface (80) facing the ball (16) housed in the pocket (76), the guide surface (80) preferably being at least partially located inside a first pitch cylinder (CP1) having a base on a first pitch circle that passes through the centers of the balls (16) in the first row and is centered on the rotation axis (100), and preferably being at least partially located between the first pitch surface (PP1) and the second pitch surface (PP2). Aspect 6 A rotating assembly (10) according to aspect 5, characterized in that for each pocket (76), the cylindrical portion (721) connecting the two adjacent pawls (74) has an end guide surface (82) facing the ball (16) housed in the pocket (76), and the end guide surface (82) is preferably located at least partially radially outside the first pitch cylinder (CP1). Aspect 7 A rotating assembly (10) according to any one of aspects 4 to 6, characterized in that the first bearing retainer (70) further comprises additional claws (84) arranged on the outer periphery of the cylindrical portion (72), each of the additional claws (84) being associated with one of the claws (74) and having a free distal end (86) located radially outward and opposite the associated claw (74). Aspect 8 A rotating assembly (10) according to aspect 7, characterized in that for each pocket (76), two additional pawls (84) associated with the two adjacent pawls (74) each include an additional concave guide surface (88) facing the ball (16) housed in the pocket (76), and the additional guide surface (88) is located at least partially outside the first pitch cylinder (CP1) and between the first pitch plane (PP1) and the second pitch plane (PP2). Aspect 9 A rotating assembly (10) according to aspect 5, characterized in that for each pocket (76), the two adjacent pawls (74) each include an additional concave guide surface (88) facing the ball (16) housed in the pocket (76), the additional guide surface (88) being at least partially outside the first pitch cylinder (CP1) and at least partially between the first pitch surface (PP1) and the second pitch surface (PP2). Aspect 10 10. The rotating assembly according to any one of claims 3 to 8, wherein the cylindrical portion of the first bearing cage further comprises a planar annular lamination surface facing axially away from the pawls and a centering bearing rotationally symmetrical with respect to the reference axis of the first bearing cage, the first bearing cage further comprising a plane facing axially away from the annular lamination surface, the plane overlapping the planar annular lamination surface when viewed in orthogonal projection in a lamination plane including the planar annular lamination surface, and a centering surface that is radially inverted when viewed in orthogonal projection in the lamination plane to face the centering bearing, and the centering surface and the centering bearing face face the annular lamination surface. Aspect 11 The rotating assembly (10) according to any one of the first to tenth aspects, further comprising the second one-piece bearing cage (90), the second one-piece bearing cage (90) having the cylindrical portion (92) defining a reference axis of the second bearing cage (90) and pawls (94) disposed on an outer periphery of the cylindrical portion (92) of the second bearing cage (90) and defining pockets for accommodating the second row of balls (18), the cylindrical portion (92) of the second bearing cage (90) preferably being disposed on the second pitch surface (PP2) side opposite the first pitch surface (PP1). the claws (94) of the second bearing retainer (90) protrude from a cylindrical portion (92) of the second bearing retainer (90) toward the first pitch surface (PP1) that intersects the second pitch surface (PP2), the claws (94) of the second bearing retainer (90) have free distal ends (98), and each of the pockets is defined by two adjacent ones of the claws (94) of the second bearing retainer (90) and a portion of the cylindrical portion (92) that connects the two adjacent claws (94). Aspect 12 A rotating assembly (10) according to any one of the first to 11 aspects, wherein a ball diameter DC1 of the first row of balls (16) is equal to or less than a ball diameter DC2 of the second row of balls (18). Aspect 13 13. The rotating assembly (10) according to any one of aspects 1 to 12, wherein the second inner ring portion (36) is shrink-fitted to a shrink-fit bearing (52) of the first inner ring portion (30, 34). Aspect 14 14. The rotating assembly (10) of any one of claims 1 to 13, wherein the outer subassembly (12) constitutes a fixed subassembly (12) of a drive wheel guide (10) of the motorized vehicle, and the inner subassembly (14) constitutes a rotating subassembly (14) of the drive wheel guide (10) of the motorized vehicle, and is rotatable relative to the fixed subassembly (12) about the rotation axis (100), and the rotating subassembly has a wheel hub (30) including a flange (38) having an interface for mounting a wheel rim (40) or a brake disc (41). the mounting flange (38) forms a mounting surface (42) of the wheel rim (40) or the brake disc (41) axially facing 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 first inner ring portion (30, 34) being formed by the wheel hub (30) or being shrink-fitted to the wheel hub (30), and the second inner ring portion (36) being shrink-fitted to a shrink-fit bearing (52) of the wheel hub (30). Aspect 15 A rotating assembly (10) as described in aspect 14, characterized in that the rotating subassembly further comprises a transmission bowl (32), and the inner ring portion (36) supports the transmission bowl (32) at annular contact surfaces (58, 60) extending at least radially relative to the rotation axis (100). Aspect 16 A rotating assembly (10) as described in aspect 15, characterized in that the annular contact surfaces (58, 60) are at least partially, preferably completely, disposed between the first pitch surface (PP1) and the second pitch surface (PP2). Aspect 17 17. The rotating assembly (10) of any one of aspects 14 to 16, wherein the wheel hub (30) is a solid, one-piece metal part.

Claims

1. A rotating assembly (10) comprising: an outer subassembly (12) centered on a common axis of rotation (100) and including annular first and second outer ring raceways (22, 24); an inner subassembly (14) including a first inner ring portion (30, 34) and a second inner ring portion (36), wherein the first inner ring portion (30, 34) on which a first inner ring raceway surface (56) is formed has a raceway bottom diameter DI1, and the second inner ring portion (36) on which a second inner ring raceway surface (62) is formed has a raceway bottom diameter DI2 larger than the raceway bottom diameter DI1 of the first inner ring raceway surface (56), and the second inner ring portion (36) and the first inner ring portion (30, 34) are fixed relative to each other; and balls (16, 18) that form a first row of balls (16) rollable on the first outer ring raceway surface (22) and the first inner ring raceway surface (56) and a second row of balls (18) rollable on the second outer ring raceway surface (24) and the second inner ring raceway surface (62) to relatively guide the outer sub-assembly (12) and the inner sub-assembly (14) that rotate about the rotation axis (100), the first row of balls (16) having a diameter DC1, and a first pitch plane (PP1) including the centers of the first row of balls (16) being disposed a non-zero distance L from a second pitch plane (PP2) including the centers of the second row of balls (18), 1. A rotating assembly (10) characterized in that, in a cross-sectional plane (PC) perpendicular to the rotation axis (100), the outer diameter (Φ) of the second inner ring portion (36) located between the first pitch plane (PP1) and the second pitch plane (PP2) and measured at a measurement distance DM from the first pitch plane (PP1) is greater than a predetermined threshold value VS, and the following formula is true: [Equation 1]

2. 2. The rotating assembly (10) according to claim 1, wherein the second inner ring portion (36) includes an axial end face (57) that faces axially toward the first pitch plane (PP1) and supports axially against a bearing surface (59) of the first inner ring portion (30, 34), the axial end face (57) being disposed at a point in a transverse plane (PB) located between the first pitch plane (PP1) and the second pitch plane (PP2) at a distance D from the first pitch plane (PP1) that is less than half the diameter DC1 of the first row of balls (16).

3. 3. A rotating assembly (10) according to claim 1 or 2, further comprising an integral first bearing cage (70), characterized in that the first bearing cage (70) comprises a cylindrical portion (72) defining a reference axis (300) of the first bearing cage (70), and pawls (74) distributed around the periphery of the cylindrical portion (72) to define pockets (76) for accommodating the first row of balls (16).

4. 4. The rotating assembly (10) according to claim 3, wherein the cylindrical portion (72) is arranged on one side of the first pitch plane (PP1) opposite to the second pitch plane (PP2), the pawls (74) protrude from the cylindrical portion (72) across the first pitch plane (PP1) toward the second pitch plane (PP2), the pawls (74) have free distal ends (78), and each of the pockets (76) is bounded by two adjacent ones of the pawls (74) of the first bearing cage (70) and a portion of a cylindrical portion (721) connecting the two adjacent pawls (74).

5. 5. The rotating assembly (10) according to claim 4, wherein for each pocket (76), the two adjacent pawls (74) each have a concave guide surface (80) facing the ball (16) housed in the pocket (76), the guide surface (80) being at least partially located inside a first pitch cylinder (CP1) having a base defined by a first pitch circle that passes through the centers of the first row of balls (16) and is centered on the rotation axis (100), and the guide surface (80) being at least partially present between the first pitch surface (PP1) and the second pitch surface (PP2).

6. 6. A rotating assembly (10) according to claim 5, characterized in that for each pocket (76), the cylindrical portion (721) connecting the two adjacent pawls (74) comprises an end guide surface (82) facing the ball (16) housed in the pocket (76), the end guide surface (82) being located at least partially radially outside the first pitch cylinder (CP1).

7. 7. A rotating assembly (10) according to claim 5 or 6, wherein the first bearing retainer (70) further comprises additional pawls (84) arranged on the outer periphery of the cylindrical portion (72), each of the additional pawls (84) being associated with one of the pawls (74) and having a free distal end (86) at a position radially outward and opposite the associated pawl (74).

8. 8. The rotating assembly (10) according to claim 7, wherein, for each pocket (76), two additional pawls (84) associated with the two adjacent pawls (74) each include an additional concave guide surface (88) facing the ball (16) housed in the pocket (76), the additional guide surface (88) being located at least partially outside the first pitch cylinder (CP1) and between the first pitch plane (PP1) and the second pitch plane (PP2).

9. 6. The rotating assembly (10) according to claim 5, wherein for each pocket (76), the two adjacent pawls (74) each include an additional concave guide surface (88) facing the ball (16) housed in the pocket (76), the additional guide surface (88) being at least partially outside the first pitch cylinder (CP1) and at least partially between the first pitch plane (PP1) and the second pitch plane (PP2).

10. 9. The rotating assembly according to claim 3, wherein the cylindrical portion of the first bearing cage further comprises an annular lamination surface facing axially away from the pawls and a centering bearing rotationally symmetrical about the reference axis of the first bearing cage, the first bearing cage further comprising a plane facing axially away from the annular lamination surface, the plane overlapping the annular lamination surface when viewed in an orthogonal projection on a lamination plane including the annular lamination surface, and a centering surface that is radially inverted when viewed in an orthogonal projection on the lamination plane so as to face the centering bearing, and wherein the centering surface faces the centering bearing when a plurality of the first bearing cages are stacked.

11. 11. A rotating assembly (10) according to any one of claims 1 to 10, further comprising a second bearing cage (90) having a cylindrical portion (92) defining a reference axis of the one-piece second bearing cage (90) and pawls (94) disposed on an outer periphery of the cylindrical portion (92) of the second bearing cage (90) and defining pockets for accommodating the second row of balls (18), wherein the cylindrical portion (92) of the second bearing cage (90) is disposed on a side of the second pitch plane (PP2) opposite the first pitch plane (PP1), and the second bearing cage a rotating assembly (10) in which the claws (94) of a retainer (90) protrude from a cylindrical portion (92) of the second bearing retainer (90) across the second pitch plane (PP2) toward the first pitch plane (PP1), the claws (94) of the second bearing retainer (90) having free distal ends (98), and each of the pockets is defined by two adjacent ones of the claws (94) of the second bearing retainer (90) and a portion of the cylindrical portion (92) of the second bearing retainer (90) that connects the two adjacent claws (94).

12. 12. A rotating assembly (10) according to any one of claims 1 to 11, characterized in that a ball diameter DC1 constituting the first row of balls (16) is equal to or less than a ball diameter DC2 of the balls constituting the second row of balls (18).

13. 13. A rotating assembly (10) according to any one of claims 1 to 12, characterized in that the second inner ring portion (36) is shrink-fitted to a shrink-fit bearing (52) of the first inner ring portion (30, 34).

14. 14. A rotating assembly (10) according to any one of claims 1 to 13, wherein the outer subassembly (12) constitutes a fixed subassembly (12) of a drive wheel guide (10) of a motorized vehicle, and the inner subassembly (14) constitutes a rotating subassembly (14) of the drive wheel guide (10) of the motorized vehicle, and is rotatable relative to the fixed subassembly (12) about the rotation axis (100), and the rotating subassembly includes a wheel hub (30) including a flange (38) having an interface for mounting a wheel rim (40) or a brake disc (41). wherein the flange (38) forms a mounting surface (42) of the wheel rim (40) or the brake disc (41) axially facing 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 first inner ring portion (30, 34) being formed by the wheel hub (30) or being shrink-fitted to the wheel hub (30), and the second inner ring portion (36) being shrink-fitted to a shrink-fit bearing (52) of the wheel hub (30).

15. 15. The rotating assembly (10) of claim 14, wherein the rotating subassembly further comprises a transmission bowl (32), and the second inner ring portion (36) supports the transmission bowl (32) at an annular contact surface (58, 60) extending at least radially relative to the rotational axis (100).

16. 16. A rotating assembly (10) according to claim 15, characterized in that the annular contact surface (58, 60) is at least partially disposed between the first pitch surface (PP1) and the second pitch surface (PP2).

17. 17. A rotating assembly (10) according to any one of claims 14 to 16, characterized in that the wheel hub (30) is a solid, one-piece metal part.

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