Axle assembly and method of manufacture

An axle assembly includes an axle housing having first and second arm portions that extend in opposite directions from a center portion, and an axle interface bracket that is fixedly mounted to the first arm portion. The axle interface bracket includes a base, holes extend from a bottom surface of the base, and channel walls that extend from the base and are disposed opposite the bottom surface.

TECHNICAL FIELD

This disclosure relates to an axle assembly for a vehicle, and more particularly, to an axle assembly having an axle interface bracket and a suspension interface bracket.

BACKGROUND

An axle and suspension assembly is disclosed in U.S. Pat. No. 7,967,307.

SUMMARY

In at least one approach, an axle interface bracket is provided. The axle interface bracket may include a base having a bottom surface, a first set of holes, and a second set of holes. The first and second sets of holes may extend from the bottom surface. The axle interface bracket may further include first and second channel walls that extend from the base. The first and second channel walls may be disposed opposite the bottom surface. The first and second channel walls may cooperate with the base to define a channel for receiving an arm of an axle housing. The first channel wall may extend from the base between the first set of holes and the channel, and the second channel wall may extend from the base between the second set of holes and the channel.

In at least one approach, an axle assembly is provided. The axle assembly may include an axle housing having first and second arm portions that extend in opposite directions from a center portion. The axle assembly may further include an axle interface bracket that is fixedly mounted to the first arm portion. The axle interface bracket may include a base having a bottom surface, a first set of holes, and a second set of holes. The first and second sets of holes may extend from the bottom surface. The axle interface bracket may further include first and second channel walls that extend from the base. The first and second channel walls may be disposed opposite the bottom surface. The first and second channel walls may cooperate with the base to define a channel for receiving an arm of an axle housing. The first channel wall may extend from the base between the first set of holes and the channel, and the second channel wall may extend from the base between the second set of holes and the channel.

In at least one approach, a method of assembling an axle assembly is provided. The method may include providing an axle interface bracket that has a base having a bottom surface, first and second sets of holes that extend from the bottom surface, and first and second channel walls that extend from the base and are disposed opposite the bottom surface. The first and second channel walls may cooperate with the base to define a channel for receiving an arm of an axle housing. The method may further include positioning an arm portion of an axle housing in the channel. The method may further include welding the arm portion to the first and second channel walls.

DETAILED DESCRIPTION

Referring toFIG. 1, an axle assembly10may be provided for a vehicle (not shown). An axle assembly10may be utilized in a tandem or other multiple axle arrangement in which each axle assembly10is supported on a frame by a four bar linkage so that each axle moves independently of one another.

The axle assembly10may be adapted to provide torque to associated wheel assemblies via wheel axle output shafts of the vehicle. In this way, the axle assembly10may be referred to as a drive axle assembly. In at least one approach, the vehicle is a bus or a coach vehicle. For example, the axle assembly10may be a rear-axle assembly of a bus. In still other approaches, the axle assembly10may be provided for an on-highway truck, an off-highway vehicle, a trailer, a military vehicle, a construction vehicle, a utility vehicle, a fire vehicle, or an emergency vehicle.

The axle assembly10may include an axle housing12. The axle housing12may include a center portion14and at least one arm portion16. The center portion14may be disposed proximate the center of the axle housing12. The center portion14may receive various components of the axle assembly10. For example, the center portion14may define a cavity that may receive a differential assembly. A lower region of the center portion14may at least partially define a sump portion that may contain lubricant. Splashed lubricant may flow down the sides of the center portion14and may flow over internal components of the axle assembly10and gather in the sump portion.

One or more arm portions16may extend from the center portion14. For example, two arm portions16may extend in opposite directions from the center portion14. The arm portions16may have substantially similar configurations. In at least one approach, the arm portions16may each have a hollow configuration such that the arm portions16define an arm cavity that may receive a corresponding axle shaft. In at least another approach, the arm portions16may not be hollow.

An arm portion16may define one or more substantially planar surfaces. For example, an arm portion16may define a substantially quadrilateral cross-section about a longitudinal axis18that may extend through the arm portion16of the axle housing12. The substantially quadrilateral cross-section may include four substantially planar exterior wall surfaces. In still another approach, an arm portion16may define a substantially tubular cross-section about the longitudinal axis18.

The axle assembly10may include an axle bracket assembly20adapted to connect the axle housing12to a suspension system (discussed in greater detail elsewhere herein).

Referring momentarily toFIG. 2, the axle bracket assembly20may be a multi-component bracket assembly that may include an axle interface bracket22and a suspension interface bracket24. The axle interface bracket22may include a body defining a base30. The base30may define a substantially quadrilateral base portion.

As shown in the approach ofFIG. 3, the base30may have having a first set of holes32a,32band a second set of holes34a,34b. For example, the first and second sets of holes may be disposed through axle flange regions of the axle interface bracket22.

In at least one approach, members32a,32bof the first set of holes and the members34a,34bof the second set of holes may disposed along different non-intersecting axes. For example, the holes may be arranged such the holes are not coaxially disposed.

In at least one approach, the holes may be through-holes. As used herein, holes are through-holes if they extend through an entire thickness of the body through which they are disposed. In this way, the first and second sets of holes may extend from a top surface of the base30to a bottom surface of the base30. As such, and as will be discussed in greater detail elsewhere herein, a fastener may be passed through an entire height of a through-hole. In still another approach, the holes may not be through-holes. As such, the holes may not pass through an entire thickness of the body through which they are disposed. Such holes may be, for example, internally threaded holes for receiving a threaded fastener.

The axle interface bracket22may further include channel walls36. For example, the axle interface bracket22may include two channel walls36. The channel walls36may extend from the base30. In at least one approach, the channel walls36may be parallel channel walls. The channel walls36may extend longitudinally; for example, along axes parallel to the longitudinal axis18. The channel walls36may be disposed between the first set of holes32a,32band the second set of holes34a,34b. The channel walls36may define a channel38between the channel walls36. The channel38may be suitably dimensioned to receive the axle housing12; for example, at the arm portions16. In at least one approach, a first channel wall36may extend from the base30between the first set of holes32a,32band the channel38, and a second channel wall36may extend from the base30between the second set of holes34a,34band the channel38.

The axle interface bracket22may be secured to the axle housing12. In at least one approach, the axle interface bracket22may be welded to the axle housing12at an arm portion16. For example, the axle interface bracket22may be welded to the axle housing12at the channel walls36. More particularly, the axle interface bracket22may be welded to the axle housing12at peripheral edge regions of the channel walls36. In this way, a first weld may connect a first channel wall36to an arm portion16, and a second weld may connect a second channel wall36to the arm portion16. In at least one approach, the suspension interface bracket24may be mounted to the axle interface bracket22prior to welding the arm portion16to the channel walls36.

Referring toFIG. 4, the base30may define a mating surface. The mating surface may have, for example, a bottom surface40of the base30. As used herein, “bottom” may refer to the orientation of the axle interface bracket22as shown inFIGS. 1-3. The bottom surface40may be a substantially planar surface. The bottom surface40may include the first set of holes32a,32b. In at least one approach, the bottom surface40may further include one or more dowel apertures42a,42b. For example, a first dowel aperture42amay be arranged generally between through-hole32aand through-hole32bof the first set of holes, and a second dowel aperture42bmay be arranged generally between through-hole34aand through-hole34bof the second set of holes.

In at least one approach, the dowel apertures42a,42bmay be arranged on a central longitudinal axis44extending equidistant between a central axis of a through-hole of the first set of holes (e.g., through-hole32a) and a central axis of a through-hole of the second set of holes (e.g., through-hole34a). As used herein, the longitudinal axis44may be an axis parallel to the longitudinal axis18ofFIG. 1. In still another approach, the dowel apertures42a,42bmay be offset from the central longitudinal axis44such that the central longitudinal axis44does not extend through the dowel apertures42a,42b. In still another approach, a first dowel aperture (e.g., dowel aperture42a) may be arranged on the central longitudinal axis44, and a second dowel aperture (e.g., dowel aperture42b) may be offset from the central longitudinal axis44.

In still another approach, the dowel apertures42a,42bmay be offset different distances from the central longitudinal axis44. For example, a first dowel aperture (e.g., dowel aperture42a) may be offset a first distance D1from the central longitudinal axis44, and a second dowel aperture (e.g., dowel aperture42b) may be offset a second distance D2from the central longitudinal axis44, such that the second distance D2is different (e.g., greater) than the first distance D1.

In at least one approach, the dowel apertures42a,42bmay be arranged on a central transverse axis46extending equidistant between central axes of the first and second individual holes32a,32b(and which may also be equidistant between central axes of holes34a,34b), As used herein, the transverse axis46may be an axis generally orthogonal to the longitudinal axis18ofFIG. 1. In still another approach, the dowel apertures42a,42bmay be offset from the transverse axis46such that the transverse axis46does not extend through the dowel apertures42a,42b. In still another approach, a first dowel aperture (e.g., dowel aperture42a) may be arranged on the transverse axis46, and a second dowel aperture (e.g., dowel aperture42b) may be offset from the transverse axis46.

In still another approach, the dowel apertures42a,42bmay be offset different distances from the transverse axis46. For example, a first dowel aperture (e.g., dowel aperture42a) may be offset a first distance D3from the transverse axis46, and a second dowel aperture (e.g., dowel aperture42b) may be offset a second distance D4from the transverse axis46, such that the second distance D4is different (e.g., greater) than the first distance D3.

In still another approach, the dowel apertures42a,42bmay have different diameters. For example, dowel aperture42amay have a diameter that is greater or smaller than a diameter of dowel aperture42b.

The offsets and variable dowel aperture diameters may assist a user in assembling an axle interface bracket22with a suspension interface bracket24. More particularly, the offsets and variable dowel aperture diameters may assist a user in assembling the axle interface bracket22in a proper orientation relative to the suspension interface bracket24.

The axle interface bracket22may include a damper bracket50. The damper bracket50may include one or more damper mounting walls52. For example, first and second damper mounting walls52may extend from a channel wall36in a direction that extends away from the channel38. The first damper mounting wall52may be spaced apart from the second damper mounting wall52. The damper bracket50may be located on the axle interface bracket22such that a first member (e.g., hole32a) of the first set of holes is located opposite a first damper mounting wall52from the cavity, and such that a second member (e.g., hole32b) of the first set of holes is located opposite a second damper mounting wall52from the cavity.

The damper mounting walls52may define one or more mounting holes53adapted to facilitate mounting of a portion of a suspension system. More particularly, the first and second damper mounting walls52, along with at least one of a channel wall36and the base30, may cooperate to at least partially define a cavity for receiving a portion of a damper54. For example, as shown inFIG. 1, the damper bracket50may receive an end of a damper54within the cavity. The damper54may be pivotably connected to the axle interface bracket22at the damper bracket50such that the damper54is rotatable relative to the axle interface bracket22. The damper54may be a shock absorber, a strut, or other suitable damper.

As discussed, the axle bracket assembly20may include a suspension interface bracket24. The suspension interface bracket24may be a single-piece construction, or may be a multi-piece construction. For example, in at least one approach shown inFIGS. 1 and 2, the suspension interface bracket24may include multiple discrete suspension interface brackets24a,24b. The discrete suspension interface brackets24a,24bmay be secured to the axle interface bracket22such that the discrete suspension interface brackets24a,24bare spaced apart and do not contact an adjacent suspension interface bracket24a,24b. The suspension interface brackets24a,24bmay have the same configuration. In this way, the suspension interface brackets24a,24bmay be installed in an interchangeable arrangement. The suspension interface brackets24a,24bmay instead have different configurations.

The discrete suspension interface brackets24a,24bmay be spaced apart such that a portion of a suspension system may be received therebetween. For example, the discrete suspension interface brackets24a,241may receive an end of a walking beam56, as shown inFIG. 1. The walking beam56may be pivotably connected to the discrete suspension interface brackets24a.24bsuch that the walking beam56is rotatable relative to the discrete suspension interface brackets24a,24b.

In at least another approach, shown inFIG. 5, the suspension interface bracket may be a unitary suspension interface bracket24′. The suspension interface bracket24′ may include a base region60. The base region60may define a substantially quadrilateral base portion. One or more posts62may extend from the base region60. The posts62may be spaced apart such that a portion of a suspension system, such as walking beam56, may be received therebetween.

The suspension interface bracket24,24′ may define a mating surface. The mating surface may have, for example, a top surface70of the base30. As used herein, “top” may refer to the orientation of the suspension interface bracket24as shown inFIGS. 1, 2, and 5. The top surface70may be a substantially planar mating surface. The top surface70may include a third set of holes72a,72band a fourth set of holes74a,74b. For example, the third and fourth sets of holes may be disposed through the top surface70at suspension flange regions of the suspension interface bracket24.

In the assembled configuration, the top surface70may engage the bottom surface40of the axle interface bracket22. Also in the assembled configuration, the third set of holes72a,72bmay be substantially aligned (e.g., along central axes of the holes72a,72b) with the first set of holes32a,32b. Also in the assembled configuration, the fourth set of holes74a,74bmay be substantially aligned (e.g., along central axes of the holes74a,74b) with the second set of holes34a,34b.

In at least one approach, the top surface70may further include one or more dowel apertures76a,76b. For example, a third dowel aperture76amay be arranged generally between through-hole72aand through-hole72bof the third set of holes, and a second dowel aperture76bmay be arranged generally between through-hole74aand through-hole74bof the fourth set of holes. In at least one approach, the dowel apertures76a,76bmay be disposed in alignment (or substantially alignment) with the dowel apertures42a,42bof the axle interface bracket22.

The holes may be dimensioned to receive mechanical fasteners80therein. The mechanical fasteners80may be any mechanical fastener (or combination of mechanical fasteners) suitable to substantially inhibit movement of the suspension interface bracket24relative to the axle interface bracket22. For example, the mechanical fasteners80may be threaded bolt and nut assemblies.

The dowel apertures may be dimensioned to receive dowels82therein. The dowels82may be received in opposing dowel apertures42a,76aand42b,76b. The dowels82may assist a user during assembly of the axle bracket assembly20. The dowels82may also provide additional shear resistance. The dowels82may be used to provide additional shear resistance in locations in which mechanical fasteners80may not be desirable. For example, packaging concerns may limit the ability to locate mechanical fasteners within the damper bracket50of the axle interface bracket22.

In at least one approach, the axle interface bracket22and the suspension interface bracket24may be different materials. For example, the axle interface bracket22may be formed of a first material, such as a casting or steel casting. The suspension interface bracket24may be formed of a second material, such as a cast or steel stamping. The different materials may have different material chemistries. The different material chemistries may be, for example, different carbon equivalent. In this way, dissimilar materials can be used for the axle interface bracket22and the suspension interface bracket24. Dissimilar materials may be beneficial or necessary for various reasons, such as weld compatibility, strength and durability reasons, cost reasons, etc.

In at least one approach, a method of assembling an axle assembly is provided. The method may include providing an axle interface bracket that has a base having a bottom surface, first and second sets of holes that extend from the bottom surface, and first and second channel walls that extend from the base and are disposed opposite the bottom surface. The first and second channel walls may cooperate with the base to define a channel for receiving an arm of an axle housing. The method may further include positioning an arm portion of an axle housing in the channel. The method may further include welding the arm portion to the first and second channel walls.

The method may further include mounting a suspension interface bracket to the bottom surface of the axle interface bracket. In at least one approach, the method may further include mounting the suspension interface bracket to the axle interface bracket after welding the arm portion to the first and second channel walls. In at least another approach, the method may further include mounting the suspension interface bracket to the axle interface bracket prior to welding the arm portion to the first and second channel walls.

In at least one approach, a method of assembling a drive axle assembly is provided. The method may include welding an axle interface bracket to an axle housing. The interface bracket may be formed of a first material having a first carbon equivalent. The method may further include securing a suspension interface bracket to the axle interface bracket through at least a plurality of mechanical fasteners. The suspension interface bracket may be formed of a second material having a second carbon equivalent different than the first carbon equivalent.