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EP-4108494-B1 - AXLE ASSEMBLY HAVING AN INTERAXLE DIFFERENTIAL UNIT

EP4108494B1EP 4108494 B1EP4108494 B1EP 4108494B1EP-4108494-B1

Inventors

  • NAIK, MAHESH
  • RANJAN, Ramesh
  • KWASNIEWSKI, DALE

Dates

Publication Date
20260506
Application Date
20220610

Claims (15)

  1. An axle assembly (10) comprising: an input shaft (24) that is rotatable about an axis (50); an output shaft (40) that is rotatable about the axis (50); and an interaxle differential unit (26) that includes: a first side gear (70) that is rotatable about the axis (50) and is selectively couplable to the input shaft (24); a second side gear (72) that is rotatable about the axis (50) with the output shaft (40); a spider (74) that is rotatable about the axis (50) with the input shaft (24); a pinion gear (76) that is rotatably disposed on the spider (74) and that meshes with the first side gear (70) and the second side gear (72); and a case (78) that encircles the first side gear (70) and the spider (74), wherein the case (78) has an integral drive gear (120) that has teeth that face away from the axis (50), wherein the first side gear (70) includes a first side gear spline (86) that has teeth that are arranged around the axis (50) and that extend away from the axis (50), and the case (78) has a case spline (124) that has teeth that are arranged around the axis (50) and that extend toward the axis (50), wherein at least one tooth of the first side gear spline (86) has a tip surface (90) that faces away from the axis (50) and a protrusion (92) that extends from the tip surface (90) in a direction that extends away from the axis (50), wherein the teeth of the case spline (124) mate with the teeth of the first side gear spline (86) such that the protrusion (92) is received inside the case (78) and engages the case spline (124).
  2. The axle assembly of claim 1 wherein the case (78) and the integral drive gear (120) are rotatable together about the axis (50) such that the integral drive gear (120) is not rotatable with respect to the case (78).
  3. The axle assembly of claim 1 wherein the integral drive gear (120) encircles the first side gear (70).
  4. The axle assembly of claim 1 or claim 3 wherein the integral drive gear (120) encircles a portion of the spider (74).
  5. The axle assembly of claim 1 wherein the case (78) is fixedly coupled to the first side gear (70) such that the first side gear (70) is not rotatable with respect to the case (78) and the integral drive gear (120).
  6. The axle assembly of claim 1 wherein the teeth of the integral drive gear (120) mesh with a driven gear (30) that is rotatable about a second axis (180) with a drive pinion (32).
  7. The axle assembly of claim 1 wherein the case (78) has a first case end (110) and a second case end (112) that is disposed opposite the first case end (110), wherein the integral drive gear (120) is disposed adjacent to the first case end (110) and is spaced apart from the second case end (112).
  8. The axle assembly of claim 1 wherein the case (78) has a first case end (110) and a second case end (112) that is disposed opposite the first case end (110), wherein the case (78) includes a concave groove (122) that encircles the axis (50) and that extends between the integral drive gear (120) and the second case end (112).
  9. The axle assembly of claim 8 wherein a through hole (140) extends from the concave groove (122) toward the axis (50).
  10. The axle assembly of claim 1 wherein the integral drive gear (120) encircles the protrusion (92) and does not encircle a portion of the first side gear spline (86).
  11. The axle assembly of claim 1 wherein the first side gear (70) has a face gear (82) that is disposed at a first end of the first side gear (70) that faces away from the spider (74).
  12. The axle assembly of claim 11 wherein at least one tooth of the face gear (82) extends from a first tooth of the first side gear spline (86) to a second tooth of the first side gear spline (86).
  13. The axle assembly of claim 11 further comprising a clutch collar (28) that is rotatable about the axis (50) with the input shaft (24), wherein the clutch collar (28) is selectively couplable with the face gear (82) to inhibit rotation of the first side gear (70) about the axis (50) with respect to the input shaft (24).
  14. The axle assembly of claim 13 wherein the clutch collar (28) is separated from and not engageable with the case (78) and the integral drive gear (120).
  15. The axle assembly of claim 1 wherein the spider (74) is rotatable with respect to the case (78).

Description

TECHNICAL FIELD This relates to an axle assembly having an interaxle differential unit. BACKGROUND An axle assembly having an interaxle differential unit is disclosed in U.S. Patent No. 9,816,603. CN110529577A discloses an axle assembly comprising: an input shaft that is rotatable about an axis; an output shaft that is rotatable about the axis; and an interaxle differential unit that includes: a first side gear that is rotatable about the axis; a second side gear that is rotatable about the axis with the output shaft; a spider that is rotatable about the axis with the input shaft;a pinion gear that is rotatably disposed on the spider and that meshes with the first side gear and the second side gear; and a case that encircles the first side gear and the spider, wherein the case has an integral drive gear that has teeth that face away from the axis. CN112664636A discloses an inter-axle differential unit that has a differential housing that is detached from a driving cylindrical gear. EP3095634A2 discloses an interaxle differential unit that has a spider and that is detached from and rotatable with respect to a drive gear. SUMMARY In at least one embodiment, an axle assembly is provided. The axle assembly includes an input shaft that is rotatable about an axis; an output shaft that is rotatable about the axis; and an interaxle differential unit that includes: a first side gear that is rotatable about the axis and is selectively couplable to the input shaft; a second side gear that is rotatable about the axis with the output shaft; a spider that is rotatable about the axis with the input shaft; a pinion gear that is rotatably disposed on the spider and that meshes with the first side gear and the second side gear; and a case that encircles the first side gear and the spider, wherein the case has an integral drive gear that has teeth that face away from the axis. The case and integral drive gear may be rotatable together about the axis such that the integral drive gear is not rotatable with respect to the case. The integral drive gear may encircle the first side gear. The integral drive gear may encircle a portion of the spider. The case may be fixedly coupled to the first side gear such that the first side gear is not rotatable with respect to the case and the integral drive gear. The teeth of the integral drive gear may mesh with a driven gear that is rotatable about a second axis with a drive pinion. The case may have a first case end and a second case end that is disposed opposite the first case end. The integral drive gear may be disposed adjacent to the first case end. The integral drive gear may be spaced apart from the second case end. The case may include a concave groove that encircles the axis and that extends between the integral drive gear and the second case end. A through hole may extend from the concave groove toward the axis. The first side gear includes a first side gear spline that has teeth that are arranged around the axis and that extend away from the axis. The case has a case spline that has teeth that are arranged around the axis and that extend toward the axis and that mate with the teeth of the first side gear spline. At least one tooth of the first side gear spline has a tip surface that faces away from the axis and a protrusion that extends from the tip surface in a direction that extends away from the axis. The protrusion is received inside the case and engages the case spline. The integral drive gear may encircle the protrusion. The integral drive gear may not encircle a portion of the first side gear spline. The first side gear may have a face gear that is disposed at a first end of the first side gear that faces away from the spider. The first side gear may include a first side gear spline that has teeth that are arranged around the axis and that extend away from the axis. At least one tooth of the face gear may extend from a first tooth of the first side gear spline to a second tooth of the first side gear spline. The axle assembly may further comprise a clutch collar that is rotatable about the axis with the input shaft. The clutch collar may be selectively couplable with the face gear to inhibit rotation of the first side gear about the axis with respect to the input shaft. The clutch collar may be separated from and not engageable with the case and the integral drive gear. The spider may be rotatable with respect to the case. The axle assembly may further comprise a weld that attaches the first side gear to the case. The first side gear may have a first side gear protrusion that protrudes away from the axis. The weld may extend from the first side gear protrusion to a first case end of the case. The first side gear protrusion may encircle the axis. The first side gear may further comprise an outer side that faces away from the axis and that extends axially from the first side gear protrusion toward the spider. The case may engage the outer side. BRIEF DESCRIPTION OF THE DRAWIN