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US-12617232-B2 - Motor vehicle wheel assembly

US12617232B2US 12617232 B2US12617232 B2US 12617232B2US-12617232-B2

Abstract

A motor vehicle drive wheel assembly includes a fixed subassembly that includes two outer raceways; a rotating subassembly that includes a wheel hub, two inner raceways and two rows of rolling bodies that are arranged in two pitch planes PP 1 and PP 2 . One of the inner raceways is formed on a rolling bearing ring bearing against a shoulder of the wheel hub along a bearing interface having an outer circumference of large diameter.

Inventors

  • Alexandre BAUDU
  • Vincent Pourroy-Solari

Assignees

  • NTN EUROPE

Dates

Publication Date
20260505
Application Date
20240119
Priority Date
20230126

Claims (19)

  1. 1 . A motor vehicle drive wheel assembly, comprising: a fixed sub-assembly comprising a first annular outer raceway and a second annular outer raceway centered on an axis of rotation; a rotating subassembly, capable of rotating relative to the fixed subassembly about the axis of rotation, and comprising a wheel hub comprising a flange provided with an interface for attaching a wheel rim or a brake disc, the attachment flange forming a mounting face of the wheel rim or of the brake disc axially facing in a direction of disassembly of the wheel rim or of the brake disc, the direction of disassembly being parallel to the axis of rotation, a transmission bowl, and at least one inner rolling bearing ring, the at least one inner rolling bearing ring being shrink-fitted onto a shrink-fit surface of the wheel hub, the at least one inner rolling bearing ring having a contact face facing axially in the opposite direction to the direction of disassembly, bearing against the transmission bowl at an annular contact interface, the at least one inner rolling bearing ring having an end face facing axially in the direction of disassembly, bearing against a shoulder of the wheel hub along a bearing interface having an outer circumference with a diameter DCE, the rotating subassembly further comprising a first inner raceway located opposite the first outer raceway and a second inner raceway located opposite the second outer raceway and formed on the at least one inner rolling bearing ring; and balls, forming a first row of balls having a ball diameter DB 1 and capable of rolling on the first outer raceway and the first inner raceway and a second row of balls having a ball diameter DB 2 and capable of rolling on the second outer raceway and the second inner raceway, the centers of the balls of the first row of balls being located on a pitch circle of diameter DP 1 located in a first pitch plane, the centers of the balls of the second row of balls being located on a pitch circle of diameter DP 2 located in a second pitch plane, the first pitch plane being located at a non-zero distance L from the second pitch plane in the direction of disassembly, the end face being located axially between the first pitch plane and the second pitch plane; wherein the end face of the at least one inner rolling bearing ring is located at a distance from the first pitch plane greater than half of the ball diameter DB 1 of the balls of the first row of balls and in that the relationship: DP ⁢ 1 - 8 10 ⁢ DB ⁢ 1 < DCE is satisfied.
  2. 2 . The drive wheel assembly of claim 1 , wherein the relationship: DCE < DP ⁢ 2 - 2. DB ⁢ 2 is satisfied.
  3. 3 . The drive wheel assembly of claim 2 , wherein the relationship is satisfied DCE < DP ⁢ 1
  4. 4 . The drive wheel assembly of claim 1 , wherein: the end face of the at least one inner rolling bearing ring is closer to the second pitch plane than the first pitch plane; and/or the end face of the at least one inner rolling bearing ring is located at a distance from the second pitch plane less than half of the ball diameter DB 2 of the balls of the second row of balls.
  5. 5 . The drive wheel assembly of claim 1 , wherein one or more of the following relationships are satisfied: L ≥ DP ⁢ 2 - DP ⁢ 1 2 ⁢ and / or ⁢ L ≤ 7 5 × DB ⁢ 1 + DB ⁢ 2 2 ⁢ and / or ⁢ 4 * L 2 + ( DP ⁢ 2 - DP ⁢ 1 ) 2 - ( DB ⁢ 1 + DB ⁢ 2 ) ≥ 2 3 × DB ⁢ 1
  6. 6 . The drive wheel assembly of claim 1 , wherein the relationship: DB ⁢ 1 + DB ⁢ 2 2 ≤ L is satisfied.
  7. 7 . The drive wheel assembly of claim 1 , wherein: the annular contact interface between the first inner raceway or the second inner raceway and the transmission bowl is located at least partially on one side of the second pitch plane opposite the first pitch plane; and/or the annular contact interface between the first inner raceway or the second inner raceway and the transmission bowl is located entirely on one side of the second pitch plane opposite the first pitch plane; and/or at least part of the annular contact interface between the at least one inner rolling bearing ring and the transmission bowl is located a distance from the second pitch plane greater than half of the ball diameter DB 2 of the balls of the second row of balls; and/or in orthogonal projection on the first pitch plane, at least part of the annular contact interface between the at least one inner rolling bearing ring and the transmission bowl is superimposed with at least part of the bearing interface between the end face of the at least one inner rolling bearing ring and the shoulder; and/or in orthogonal projection on the first pitch plane, at least part of the annular contact interface between the at least one inner rolling bearing ring and the transmission bowl is located between the second inner raceway and the outer circumference of the bearing interface between the end face of the at least one inner rolling bearing ring and the shoulder; and/or in orthogonal projection on the first pitch plane, the annular contact interface between the at least one inner rolling bearing ring and the transmission bowl and the second inner raceway are spaced apart from one another; and/or in orthogonal projection on the first pitch plane, the annular contact interface between the at least one inner rolling bearing ring and the transmission bowl and the second inner raceway are at a distance from each other greater than half of the ball diameter DB 2 .
  8. 8 . The drive wheel assembly of claim 1 , wherein the transmission bowl has a cylindrical bearing surface transition fitted into a cylindrical bore of the wheel hub and located at least partially between the first pitch plane and the second pitch plane.
  9. 9 . The drive wheel assembly of claim 8 , wherein the cylindrical bearing surface of the transmission bowl has an intersection with a plane perpendicular to the axis of rotation and tangent to the shoulder.
  10. 10 . The drive wheel assembly of claim 1 , wherein: the shrink-fit surface of the wheel hub extends at least partially between the first pitch plane and the second pitch plane; and/or the shrink-fit surface of the wheel hub extends partially from one side of the second pitch plane opposite the first pitch plane; and/or the shrink-fit surface of the wheel hub has a diameter DF such that the following relationship is satisfied: DF < DP ⁢ 1 - 10 14 · DB ⁢ 1 and/or the shrink-fit surface of the wheel hub has a diameter DF such that the following relationship is satisfied: DP ⁢ 1 - 6 5 ⁢ DB ⁢ 1 < DF
  11. 11 . The drive wheel assembly of claim 1 , wherein the bearing interface between a bearing face and the shoulder is flat.
  12. 12 . The drive wheel assembly of claim 1 , wherein: the wheel hub is a solid one-piece part; or the wheel hub comprises at least one solid one-piece part forming the flange and the shrink-fit surface, and an additional inner rolling bearing ring shrink-fitted onto the solid part, which forms the first inner raceway and the shoulder.
  13. 13 . The drive wheel assembly of claim 1 , wherein the first inner raceway faces the first row of balls in an axial direction, in the direction of disassembly and in a direction opposed to the direction of disassembly.
  14. 14 . The drive wheel assembly of claim 1 , wherein the relationship DB 1 >DB 2 is satisfied.
  15. 15 . The drive wheel assembly of claim 1 , wherein the first row of balls is guided in rotation by a cage constituting an elastically deformable open ring.
  16. 16 . A method of mounting a drive wheel assembly of claim 1 , further comprising: a step of positioning a bearing cage constituting an open, elastically deformable ring, facing the first inner raceway, by expanding the bearing cage when passing the shoulder, a subsequent step of shrink-fitting the inner rolling bearing ring on the wheel hub, and a step of positioning the balls of the first row of balls in cells of the bearing cage, either before or after the step of positioning the bearing cage.
  17. 17 . The drive wheel assembly of claim 1 , wherein the relationship is satisfied DP ⁢ 1 - 6 10 · DB ⁢ 1 < DCE
  18. 18 . The drive wheel assembly of claim 1 , wherein in orthogonal projection on the axis of rotation, at least part of the annular contact interface between the inner rolling bearing ring and the transmission bowl is positioned at a distance from the bearing interface between the inner rolling bearing ring and the shoulder, which is less than the ball diameter DB 2 of the balls of the second row of balls.
  19. 19 . The drive wheel assembly of claim 1 , wherein in orthogonal projection on the axis of rotation, at least part of the annular contact interface between the inner rolling bearing ring and the transmission bowl is positioned at a distance from the bearing interface between the inner rolling bearing ring and the shoulder, which is greater than the ball diameter DB 2 of the balls of the second row of balls.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority under 35 U.S.C. 119 to French Patent Application No. 2300717, filed Jan. 26, 2023; the disclosure of which is incorporated herein by reference in its entirety. TECHNICAL FIELD The invention relates to a motor vehicle wheel assembly. BACKGROUND A motor vehicle drive wheel assembly, once mounted on the vehicle, generally comprises a fixed subassembly intended to be secured to a suspension element of the vehicle and comprising a first outer raceway and a second outer raceway defining an axis of rotation; a rotating subassembly, capable of rotating relative to the fixed member about the axis of rotation, and comprising a wheel hub, a transmission bowl, a first inner raceway located opposite the first outer raceway, a second inner raceway located opposite the second outer raceway; and rolling bodies, forming a first row of rolling bodies between the first outer raceway and the first inner raceway and a second row of rolling bodies between the second outer raceway and the second inner raceway. The wheel hub has an attachment interface for a wheel rim and a brake disc. The assembly therefore typically has a stack of technical functions, arranged along the axis of rotation from the inside to the outside of the vehicle: transmission of torque, attachment to the suspension of the vehicle, guidance in rotation, braking and rolling, which requires a large size in the axial direction, that is to say, transverse in the coordinate system of the vehicle. It has been proposed in document FR 3,052,104 to shrink an inner rolling bearing ring for the second inner raceway onto the transmission bowl, which makes it possible to reduce the axial size for a given distance between the two rows of rolling bodies, while increasing the pitch diameter of the row of rolling bodies located on the inside of the vehicle. Insofar as the payload and the camber stiffness are increasing functions of the distance between the two rows of rolling bodies and of the pitch diameter of the rows of rolling bodies, this architecture provides a solution for reconciling reduced axial bulk and good performance in terms of payload and camber stiffness. Electric and hybrid vehicle powertrains often turn out to be bulkier than combustion engine powertrains in the width direction of the vehicle at the drive wheels, which leads to shortening of the transverse drive shafts. This shortening is undesirable because it leads to greater angles in the transmission joints. In this context, any measure making it possible to increase the space available for the transverse transmission shafts, even slightly, is desirable. There is therefore an increased need for compactness of drive wheel assemblies in the axial direction, which does not come at the expense of performance, in particular in terms of payload and rigidity. To this end, document WO 2021/148675 proposes a motor vehicle drive wheel assembly which combines axial compactness, high payload and good camber stiffness, and comprises a fixed subassembly comprising two coaxial annular outer raceways, a rotating subassembly comprising a wheel hub on which is formed an inner raceway, a transmission bowl, and at least one inner rolling bearing ring on which is formed a second inner raceway. Rolling bodies complete the assembly and form two rows of rolling bodies separated from each other, rolling on the inner and outer raceways to rotationally guide the rotating subassembly relative to the fixed subassembly. The inner ring is shrink-fitted on the wheel hub and clamped axially bearing against a shoulder formed on the wheel hub and a shoulder formed on the transmission bowl. The bearing shoulder of the inner ring on the wheel hub is positioned in the direct vicinity of the bottom of the inner raceway formed on the wheel hub. This positioning, which contributes to the axial compactness, requires a relatively small axial contact surface between the bearing shoulder of the inner ring and the wheel hub. The tension instituted when assembling the transmission bowl, the wheel hub and the inner ring causes a high contact pressure to the interface, which increases the risks of contact corrosion and/or abrasion. This results in a risk, in use, of exposing the inner raceway formed on the wheel hub to the metal particles generated at the interface between the shoulder and the inner ring, a risk which is even greater when the interface between the inner rolling bearing ring and the shoulder of the wheel hub emerges directly at the inner raceway formed on the wheel hub. This assembly can therefore in certain cases of use be subject to damage likely to limit its lifetime. SUMMARY The invention aims to propose a motor vehicle drive wheel assembly architecture, which combines axial compactness, high payload and good camber stiffness, while limiting the risks of pollution of one of the bearings by the corrosion of contact and/or abrasion. To do this, acc