Axle assembly with brake drum

Abstract

An axle assembly is disclosed, comprising a brake drum, an inner wheel, and an outer wheel. The brake drum and the inner wheel cooperate to prevent movement of the inner wheel in an inward direction. The outer wheel clamp and an outer open ring cooperate to prevent movement of the outer wheel in an outward direction.

Description

Technical Field

[0001] This article relates to an axle assembly with a brake drum and an assembly method. background

[0002] A wheel end assembly with a drum brake assembly is disclosed in U.S. Patent Application Serial No. 16 / 991,861. Invention Overview

[0003] In at least one embodiment, an axle assembly is provided. The axle assembly includes a wheel hub, a brake drum, an inner wheel, an outer wheel, an outer sheath ring, and an outer wheel clamp. The wheel hub is rotatable about an axis and has a mounting flange. The brake drum is fastened to the mounting flange. The inner wheel surrounds the brake drum. The outer wheel surrounds the wheel hub. The outer sheath ring is received inside the outer wheel and engages the wheel hub. The outer wheel clamp is received inside the outer wheel, engages the outer wheel, and is fastened to the outer sheath ring. The outer wheel clamp and the outer sheath ring cooperate to prevent movement of the outer wheel in an outward direction. The brake drum and the inner wheel cooperate to prevent movement of the inner wheel in an inward direction opposite to the outward direction. Attached Figure Description

[0004] Figure 1 This is a perspective view of an example axle assembly.

[0005] Figure 2 This is a cross-sectional view along section line 2-2.

[0006] Figure 3 This is an exploded view of a portion of the axle assembly. Detailed Implementation

[0007] As requested, detailed embodiments of the invention are disclosed herein; however, it should be understood that the disclosed embodiments are merely examples of how the invention can be implemented in various forms and alternative forms. The drawings are not necessarily to scale; some features may be exaggerated or minimized to show details of specific components. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but rather serve only as a representative basis for teaching those skilled in the art to employ the invention in various ways.

[0008] See Figure 1 An example of axle assembly 10 is shown. Axle assembly 10 can be provided for vehicles such as trucks, buses, farm equipment, mining equipment, military transport or armed vehicles, or cargo loading equipment for land, air, or sea vessels.

[0009] The axle assembly 10 can be part of a vehicle's drivetrain, transmitting torque between at least one power source and the wheel assembly. The power source can be an electric power source (such as an electric motor), a non-electric power source (such as an internal combustion engine), or a combination thereof. The wheel assembly can include tires 12 mounted on the wheels. Figure 1 The image shows four wheel components.

[0010] One or more axle assemblies 10 may be provided to the vehicle. For example, the axle assembly 10 may be a single drive axle assembly or may be configured as part of a tandem axle configuration or a multi-axle configuration that may include multiple axle assemblies connected in series. See reference Figure 1 and Figure 2 As best shown, the axle assembly 10 may include a housing assembly 20, a differential assembly 22, at least one half-shaft 24, and at least one brake assembly 26. The axle assembly 10 may also include at least one wheel end assembly, which may include a wheel hub 30, an inner wheel 32, an outer wheel 34, and a brake drum 36. The wheel end assembly may also include an outer open-end ring 42, at least one outer wheel clamp 44, and a wheel spacer 46.

[0011] See Figure 1 The housing assembly 20 can accommodate various components of the axle assembly 10. Furthermore, the housing assembly 20 facilitates the mounting of the axle assembly 10 to the vehicle. The housing assembly 20 may have a central portion 50 that can accommodate the differential assembly 22. Additionally, the housing assembly 20 may have a pair of arm portions 52 extending from the central portion 50. Each arm portion 52 can support wheel end assemblies, as well as the half-shaft 24 and brake assembly 26.

[0012] The differential assembly 22 may be at least partially received within the central portion 50 of the housing assembly 20. The differential assembly 22 may rotate about axis 60 and may transmit torque to the half-shafts 24 and their associated wheels. The differential assembly 22 may be operatively connected to the half-shafts 24 and may allow the half-shafts 24 to rotate at different speeds in a manner known to those skilled in the art.

[0013] See Figure 2 The half-shaft 24 can transmit torque from the differential assembly 22 to the corresponding traction wheel assembly. Two half-shafts 24 may be provided, such that each half-shaft 24 extends through a different arm portion 52. The half-shafts 24 may extend along an axis (such as axis 60) and be rotatable about that axis. Each half-shaft 24 may have a first end and a second end. The first end is operatively connected to the differential assembly 22. The second end may be arranged opposite to the first end and is operatively connected to the wheel hub 30.

[0014] See Figure 2 and Figure 3 Brake assembly 26 can be a friction brake, which can be configured to slow or stop the rotation of at least one associated wheel. In the illustrated configuration, brake assembly 26 is configured as a drum brake and may include a brake spider 70 and one or more brake pad assemblies 72.

[0015] The brake base plate 70 facilitates the mounting of the brake assembly 26 to the arm portion 52 of the housing assembly 20. Furthermore, the brake base plate 70 supports various components of the brake assembly 26, such as the brake pad assembly 72.

[0016] One or more brake pad assemblies 72 are movable relative to the brake backing plate 70. In the illustrated configuration, two brake pad assemblies 72 are depicted. The brake pad assemblies 72 can be received inside the brake drum 36 and can be configured to engage the brake drum. For example, the brake pad assemblies 72 may include friction material that can be disposed on the brake shoes. The friction material can engage the interior of the brake drum 36 during vehicle braking and can be spaced apart from the brake drum 36 when friction braking is not applied.

[0017] The wheel hub 30 can rotate about an axis (such as axis 60). Figure 2 As best shown, the wheel hub 30 can rotate about axis 60 relative to the arm portion 52 and the main shaft 80 which can be disposed together with the arm portion 52. The wheel hub 30 can be rotatably supported by one or more wheel bearings 82 which can be arranged on the main shaft 80. In at least one configuration and as referenced Figure 2 and Figure 3 As best shown, the wheel hub 30 may include an inner end portion 90, an outer end portion 92, a hub cavity 94, and at least one mounting flange 96. The wheel hub 30 may also include an outer surface side 100, a recess 102, and a stepped surface 104.

[0018] The inner end 90 may face the brake assembly 26, or from... Figure 2 The angle shown is facing right.

[0019] The outer end 92 can be arranged opposite to the inner end 90. The outer end 92 can face the hub cover 38 and engage the hub cover. Alternatively, another component (such as a half-shaft flange) can engage the outer end 92.

[0020] The hub cavity 94 may extend around axis 60. The hub cavity 94 may accommodate various components that can be associated with the wheel end assembly, such as main shaft 80, wheel bearing 82, seals, etc. The hub cavity 94 may also accommodate gear reduction unit 110.

[0021] The gear reduction unit 110 can operatively connect the half-shaft 24 to the wheel hub 30 and can provide a gear reduction between the half-shaft 24 and the wheel hub 30. The gear reduction unit 110 can have any suitable configuration. For example, the gear reduction unit 110 can be configured as a planetary gear set or a bevel gear set. In the illustrated configuration, the gear reduction unit 110 can be configured as a planetary gear set, which may include a sun gear 112, a planetary ring gear 114, at least one planetary gear 116, and a planetary gear carrier 118.

[0022] The sun gear 112 can rotate together with the half-shaft 24 about axis 60. The sun gear 112 may have a set of teeth that can be arranged about axis 60 and can be configured to mesh or engage with the corresponding teeth of the planet gear 116.

[0023] The planetary ring gear 114 can be configured as a ring that can extend about axis 60. The planetary ring gear 114 can surround the planetary gear 116 and can have a set of teeth that can extend toward axis 60 and can mesh or engage with the teeth of the planetary gear 116. In the configuration shown, the planetary ring gear 114 is fixed relative to the main shaft 80 and does not rotate about axis 60.

[0024] At least one planetary gear 116 may be rotatably arranged between the sun gear 112 and the planetary ring gear 114. Each planetary gear 116 may rotate about a different planetary gear axis 120. Figure 2 As best shown, each planetary gear 116 may define a hole that can be arranged along the planetary gear axis 120 and may have a set of teeth facing away from the planetary gear axis 120.

[0025] The planetary gear carrier 118 can support the planetary gears 116. In the illustrated configuration, the hubcap 38 is the planetary gear carrier 118 and is fixedly positioned relative to the wheel hub 30, such that the wheel hub 30 and the planetary gear carrier 118 can rotate together about axis 60. The planetary gear carrier 118 may include multiple shafts or pins. Each shaft or pin can be received in the bore of a corresponding planetary gear 116.

[0026] See Figure 2 and Figure 3At least one mounting flange 96 may be provided, which facilitates mounting the brake drum 36 to the wheel hub 30. The mounting flange 96 may extend away from the axis 60 and may be arranged closer to the inner end 90 than to the outer end 92. For example, the mounting flange 96 may extend from the inner end 90 toward the outer end 92. A single mounting flange 96 may be provided, which may extend continuously or discontinuously around the axis 60. Alternatively, multiple mounting flanges 96 may be provided, which may be spaced apart from each other and may be arranged around the axis 60. In the configuration shown, six mounting flanges 96 are illustrated; however, it is conceivable that more or fewer mounting flanges 96 may be provided. These mounting flanges 96 may be coplanar. The mounting flange 96 may define at least one fastener hole 130. The fastener hole 130 may be a through hole or a blind hole and may be threaded.

[0027] The outer surface side 100 may face away from the axis 60. The outer surface side 100 may be arranged near the outer end 92 of the wheel hub 30. For example, the outer surface side 100 may extend axially between the outer end 92 of the wheel hub 30 and the recess 102.

[0028] The recess 102 can be axially positioned between the outer surface side 100 and the mounting flange 96. The recess 102 can be arranged closer to the axis 60 than the outer surface side 100.

[0029] See Figure 3 The stepped surface 104 can extend from the outer surface side 100 toward the axis 60. For example, the stepped surface 104 can extend from the end of the outer surface side 100 to the bottom surface of the recess 102. In at least one configuration, the stepped surface 104 can be arranged substantially perpendicular to the axis 60. The term "substantially perpendicular" is used herein to refer to features or axes that are the same as or very close to being perpendicular, and includes features perpendicular to each other within ±2°. The stepped surface 104 can also be arranged to be non-perpendicular to the axis 60.

[0030] In the following text, the terms "inner direction" and "outer direction" are used to indicate the relative positioning of various components. The inner direction can be a direction extending along axis 60 from the end of the axle assembly 10 toward the central portion 50 of the housing assembly 20, or from... Figure 2The angle shown extends to the right. Conversely, the outer direction can be oriented opposite to the inner direction and can be a direction extending away from the center portion 50 along axis 60. The terms inner and outer are used in a similar manner to indicate relative positioning. For example, a first feature positioned inner relative to the second feature is axially positioned closer to the center portion 50 than the second feature. Conversely, a first feature positioned outer relative to the second feature can be axially positioned further away from the center portion 50 than the second feature.

[0031] See also Figure 2 The inner wheel 32 can support the tire 12. The inner wheel 32 can be mounted on the wheel hub 30 via the brake drum 36, as will be discussed in more detail below. The inner wheel 32 can surround the brake drum 36 and can contact the brake drum 36.

[0032] The outer wheel 34 may be spaced apart from the inner wheel 32 and may support a different tire 12 than the inner wheel 32. In at least one configuration, the inner wheel 32 and the outer wheel 34 may have the same configuration. Figure 2 As best shown, the outer wheel 34 may surround the wheel hub 30, the outer opening ring 42, and the outer wheel clamp 44.

[0033] Optionally, the outer wheel 34 may have a tapered surface 140. The tapered surface 140 may face the axis 60 and may be arranged in a non-parallel and non-perpendicular relationship to the axis 60. For example, as the tapered surface 140 extends in the inward direction, it may gradually extend closer to the axis 60. The outer wheel clamp 44 may engage the tapered surface 140, as will be discussed in more detail below.

[0034] See also Figure 2 and Figure 3 The brake drum 36 can be mounted to or secured to the wheel hub 30, allowing the brake drum 36 to rotate together with the wheel hub 30 about axis 60. Figure 2 As best shown, the brake drum 36 can be received inside the inner wheel 32 and can have a cylindrical portion that can extend continuously around the brake pad assembly 72. In at least one configuration, the brake drum 36 may include a first end 150, a second end 152, at least one brake drum mounting flange 154, and a set of support features 156. The brake drum 36 may also include at least one brake drum conical surface 158.

[0035] The first end 150 may face away from the brake assembly 26, or from... Figure 2 The angle shown is to the left. The first end 150 can be arranged substantially perpendicular to axis 60.

[0036] The second end 152 can be arranged opposite to the first end 150. The second end 152 can be the distal end or the free end of the brake drum 36.

[0037] The brake drum mounting flange 154 facilitates the mounting of the brake drum 36 to the mounting flange 96 of the wheel hub 30. The brake drum mounting flange 154 can be mounted to the mounting flange 96 such that the brake drum mounting flange 154 is axially positioned outward relative to the mounting flange 96, or from... Figure 2 The angle shown is axially positioned on the left side of the mounting flange 96, thereby allowing the brake drum 36 to be removed from and mounted on the wheel hub 30 without disassembling the wheel hub 30. The brake drum mounting flange 154 can be axially positioned between the first end 150 and the second end 152, and can be axially positioned closer to the first end 150 than closer to the second end 152.

[0038] The brake drum mounting flange 154 may extend toward axis 60. One or more brake drum mounting flanges 154 may be provided. Figure 3 The configuration shown illustrates a brake drum mounting flange 154 surrounding axis 60; however, it is conceivable that the brake drum mounting flange 154 may not surround axis 60 and that multiple brake drum mounting flanges may be provided.

[0039] See also Figure 2 The brake drum mounting flange 154 may define at least one fastener hole that receives a fastener 160 for attaching the brake drum 36 to the wheel hub 30. For example, the fastener 160, such as a stud or bolt, may extend through the fastener hole in the brake drum mounting flange 154 and into a corresponding fastener hole 130 in the mounting flange 96 of the wheel hub 30. The fastener 160 may have threads that engage with the threads in the fastener hole 130. A nut 162 may be tightened onto the fastener 160 on the outside of the brake drum mounting flange 154 to secure the brake drum 36.

[0040] The set of support features 156 can be arranged around axis 60, around brake drum mounting flange 154, or both. In at least one configuration, the support features 156 can be spaced apart from each other, such that a gap 170 is provided between adjacent pairs of support features 156. Figure 3It is cut by a pair of opposing gaps 170, and therefore these gaps are visible in this figure. The support feature 156 may extend off-axis relative to the brake drum mounting flange 154 and may include a support flange 172 and a protrusion 174. The gaps 170 can reduce heat transfer from the brake drum 36 to the inner wheel 32, which can help reduce the heating of the air inside the tire 12 of the inner wheel 32. For example, the gaps 170 can reduce the surface area of ​​the inner wheel 32 in contact with the brake drum 36 while still providing sufficient strength and mounting characteristics.

[0041] The support flange 172 may extend between the first end 150 and the brake drum mounting flange 154. Therefore, the support flange 172 may extend outward from the brake drum mounting flange 154. The support flange 172 may engage and support the inner wheel 32, the wheel spacer 46, or both.

[0042] The protrusion 174 may extend away from the axis 60 and may extend further away from the axis 60 than the adjacent portion of the supporting flange 172 that extends from the protrusion in the outward direction. The protrusion 174 may engage with the inner wheel 32 to restrict or prevent axial movement of the inner wheel 32 in the inward direction.

[0043] At least one brake drum conical surface 158 may be provided to the brake drum 36. For example, the brake drum conical surface 158 may extend circumferentially between adjacent pairs of support features 156. The brake drum conical surface 158 may face away from the axis 60. Furthermore, the brake drum conical surface 158 may face the inner wheel 32 and may be spaced apart from the inner wheel. The brake drum conical surface 158 may be arranged in a non-parallel and non-perpendicular relationship to the axis 60. For example, the brake drum conical surface 158 may gradually extend further away from the axis 60 as the distance from the first end 150 increases, or as the brake drum conical surface 158 extends further inward, or as the distance from the brake drum mounting flange 154 increases in the inward direction. In at least one configuration, the brake drum conical surface 158 may extend in the inward direction from the brake drum mounting flange 154.

[0044] The outer opening ring 42 can be received inside the outer wheel 34. The outer opening ring 42 can engage the wheel hub 30 and can surround the wheel hub 30. For example, the outer opening ring 42 can engage the outer surface side 100 of the wheel hub 30. In addition, the outer opening ring 42 can engage the outer wheel 34, the outer wheel clamp 44, the wheel spacer 46, or a combination thereof.

[0045] The outer opening ring 42 can be configured as a multi-piece ring that may include multiple ring segments 180. Figure 3Two ring segments 180 are shown; however, it is conceivable that more or fewer ring segments 180 may be provided. The ring segments 180 may be separate components or separate pieces that can cooperate to surround or otherwise receive the wheel hub 30. Furthermore, the ring segments 180 may facilitate assembly to the wheel hub 30 such that at least a portion of the outer open ring 42 can be received in the recess 102 of the wheel hub 30. One or more ring segments 180 may optionally be fastened to each other and / or to the wheel hub 30 (e.g., using fasteners such as bolts or pins) to facilitate the installation of other components (such as the outer wheel 34). In at least one configuration, the outer open ring 42 may be clamped to the wheel hub 30.

[0046] In at least one configuration and as Figure 2 As best shown, the outer opening ring 42 may have an inner surface 190 and an inner guide (pilot) 192.

[0047] The inner surface 190 may face the axis 60. The inner surface 190 may engage the outer surface side 100 of the wheel hub 30.

[0048] The inner guide 192 may extend or protrude from the inner surface 190 toward the axis 60 and may extend into the recess 102 of the wheel hub 30. The inner guide 192 may engage the wheel hub 30 to prevent axial movement of the outer open ring 42 in the outward direction or to prevent the outer open ring from... Figure 2 The angle shown indicates an axial movement to the left. For example, the inner guide 192 can engage the stepped surface 104 of the wheel hub 30.

[0049] See Figure 2 and Figure 3 The device may be provided with at least one outer wheel clamp 44, which can connect the outer wheel 34 to the outer open ring 42. The outer wheel clamp 44 may be received inside the outer wheel 34 and may extend between the outer wheel 34 and the outer open ring 42. Furthermore, the outer wheel clamp 44 may be fastened to the outer open ring 42. In at least one configuration, the outer wheel clamp 44 may have a mounting portion 200 and an outer flange 202.

[0050] The mounting portion 200 can be positioned on the outside relative to the outer wheel clamp 44, or from... Figure 2The angle shown is arranged on the left side of the outer wheel clamp 44. Furthermore, the mounting portion 200 may extend toward axis 60. The mounting portion 200 may define at least one fastener hole that can receive a fastener 210 for connecting the outer wheel clamp 44 to the outer open ring 42. For example, the fastener 210, such as a stud or bolt, may extend through the fastener hole in the outer wheel clamp 44 and into a corresponding fastener hole in the outer open ring 42. The fastener 210 may have threads that engage with the threads in the fastener hole of the outer open ring 42. A nut 212 may be tightened onto the fastener 210 on the outside of the mounting portion 200 to secure the outer wheel clamp 44 and prevent movement in the outward direction.

[0051] The outer flange 202 can extend from the mounting portion 200 in the inward direction, or from... Figure 2 The angle shown extends to the right. For example, the outer flange 202 may extend from the end of the mounting portion 200 and may be arranged further away from the axis 60 than the mounting portion 200. The outer flange 202 may engage the outer wheel 34 and the outer open ring 42. For example, the outer flange 202 may extend between the outer wheel 34 and the outer open ring 42. In at least one configuration, the outer flange 202 may have a tapered surface 220.

[0052] The tapered surface 220 may face away from the axis 60. Furthermore, the tapered surface 220 may be arranged in a non-parallel and non-perpendicular relationship to the axis 60. The tapered surface 220 may be axially positioned inward relative to the mounting portion 200 and may extend around a portion of the outer opening ring 42. The tapered surface 220 may be aligned with and engage with the surface of the outer wheel 34 (such as the tapered surface 140 of the outer wheel 34). Therefore, the tapered surface 220 may contact the tapered surface 140, and the tapered surface 220 may extend gradually further away from the axis 60 in an outward direction.

[0053] See also Figure 2 The wheel spacer 46 can extend from the inner wheel 32 to the outer wheel 34. In at least one configuration, the wheel spacer 46 can be configured as a ring that can surround the axis 60 and can be spaced apart from the wheel hub 30. The wheel spacer 46 can engage or contact the brake drum 36, the outer open ring 42, or a combination thereof.

[0054] A method for assembling an axle assembly 10 will now be described. The method will be described primarily from the assembled wheel hub 30 and the inner wheel 32, outer wheel 34, and brake drum 36 that have not yet been assembled to the wheel hub 30.

[0055] First, the brake drum 36 can be mounted on and installed onto the wheel hub 30. For example, the brake drum 36 can be aligned with the wheel hub 30 such that the opening of the brake drum 36 is approximately centered on the axis 60. Then, the brake drum 36 can be moved along the axis 60 in the inward direction relative to the wheel hub 30 toward the mounting flange 96, such that the brake drum mounting flange 154 can engage the mounting flange 96 of the wheel hub 30. The brake drum 36 can then be secured to the wheel hub 30 using one or more fasteners 160 and / or nuts 162, as previously discussed.

[0056] Next, the inner wheel 32 can be positioned on the brake drum 36, such that the inner wheel 32 rests on the brake drum 36 and is approximately centered on the brake drum.

[0057] The outer opening ring 42 can be installed on the wheel hub 30 so that the outer opening ring 42 can surround the wheel hub 30, and the inner guide 192 extends into the recess 102 of the wheel hub 30 and is arranged near the stepped surface 104 of the wheel hub 30.

[0058] The wheel spacer 46 and the outer wheel 34 can be mounted and secured together with the outer wheel clamp 44. For example, the nut 212 receiving the fastener 210 can be tightened to push the outer wheel clamp 44 toward the outer open ring 42. Tightening the nut 212 can push the outer wheel clamp 44, the outer wheel 34, the wheel spacer 46, and the inner wheel 32 in the inward direction, and can prevent these components from moving relative to the wheel hub 30 and the brake drum 36. Therefore, the outer wheel clamp 44 and the outer open ring 42 can cooperate to prevent the inner wheel 32 and the outer wheel 34 from moving in the outward direction, while the inner wheel 32 and the brake drum 36 can cooperate to prevent the inner wheel 32 and the outer wheel 34 from moving in the inward direction. It is also envisioned that the various components of the wheel end assembly can be keyed to each other to prevent relative rotation.

[0059] The axle assembly described above facilitates the installation of multiple wheels, which can be more easily installed and removed compared to a single, wider wheel that can support multiple tires. The spaced-apart wheels, along with the brake drums and outer open-end rings, allow associated load forces to be distributed across the wheel hubs and help transfer load forces to the wheel hubs in a manner that allows for the use of smaller, less expensive fasteners. The wheels and brake drums can be removed from the wheel hubs to provide improved access to the brake assemblies, which can help reduce the time and cost required to replace brake pad assemblies or perform other brake maintenance activities. Furthermore, the wheels and brake drums can be installed on and removed from the wheel hubs without disassembling the wheel hubs or the gear reduction units inside the wheel hubs, which can reduce maintenance costs and time and increase vehicle availability. The axle assembly described above can allow the wheel hubs to accommodate larger planetary gear sets to help increase gear reduction capacity, which can be valuable in very large or very heavy vehicles, such as mining trucks.

[0060] While exemplary embodiments have been described above, these embodiments are not intended to describe all possible forms of the invention. Rather, the terminology used herein is descriptive rather than restrictive, and it should be understood that various changes can be made without departing from the spirit and scope of the invention. Furthermore, features of various implementations of the embodiments can be combined to form other embodiments of the invention.

Claims

1. An axle assembly comprising: a wheel hub rotatable about an axis and having a mounting flange; a brake drum secured to the mounting flange; an inboard wheel encircling the brake drum; an outboard wheel encircling the wheel hub; an outboard open ring received inside the outboard wheel and engaged but not secured to the wheel hub; and an outboard wheel clamp received inside the outboard wheel, engaged but not secured to the outboard wheel, and secured to the outboard open ring, wherein the outboard wheel clamp and the outboard open ring cooperate to resist movement of the outboard wheel in an outboard direction, and the brake drum and the inboard wheel cooperate to resist movement of the inboard wheel in an inboard direction opposite the outboard direction.

2. The axle assembly of claim 1, wherein, The inboard wheel contacts the brake drum.

3. The axle assembly of claim 1, wherein, A wheel spacer extends from the inboard wheel to the outboard wheel.

4. The axle assembly of claim 3, wherein, The wheel spacer engages the brake drum and the outboard open ring.

5. The axle assembly of claim 3, wherein, The wheel spacer encircles and contacts a portion of the brake drum and the outboard open ring.

6. The axle assembly of claim 3, wherein, The wheel spacer is spaced apart from and does not engage the wheel hub.

7. The axle assembly of claim 1, wherein, The brake drum has a brake drum mounting flange extending toward the axis and defining a fastener hole receiving a fastener coupling the brake drum to the mounting flange of the wheel hub.

8. The axle assembly of claim 7, wherein, The brake drum has a set of support features arranged around the brake drum mounting flange, wherein each support feature has a support flange extending from the brake drum mounting flange in the outboard direction, wherein the support flange engages the inboard wheel and a wheel spacer extends from the inboard wheel to the outboard wheel.

9. The axle assembly of claim 8, wherein, Each support feature has a protrusion extending away from the axis and engaging the inboard wheel to resist movement of the inboard wheel in the inboard direction.

10. The axle assembly of claim 8, wherein, The support features are spaced apart from one another such that a gap is provided between adjacent pairs of support features.

11. The axle assembly of claim 7, wherein, A brake drum conical surface facing away from the axis and facing the inboard wheel is provided between an adjacent pair of support features, wherein the brake drum conical surface is spaced apart from the inboard wheel.

12. The axle assembly of claim 11, wherein, The brake drum conical surface is arranged to gradually extend further away from the axis with increasing distance from the brake drum mounting flange.

13. The axle assembly of claim 1, wherein, The wheel hub has an outboard surface side facing away from the axis and a recess arranged closer to the axis than the outboard surface side and axially positioned between the outboard surface side and the mounting flange, wherein the outboard open ring engages the outboard surface side and is partially received in the recess.

14. The axle assembly of claim 13, wherein, The wheel hub defines a step surface extending from the outboard surface side toward the axis, and the outboard open ring has an inner surface engaging the outboard surface side; and an inner guide extending from the inner surface toward the axis and engaging the step surface.

15. The axle assembly of claim 1, wherein, The outboard open ring surrounds and engages the wheel hub and has an inner guide that projects toward the axis and engages the wheel hub to resist axial movement of the outboard open ring in the outboard direction.

16. The axle assembly of claim 15, wherein, The outboard open ring has a plurality of ring segments that are separate components and cooperate to receive the wheel hub.

17. The axle assembly of claim 1, wherein, The outboard open ring extends from the wheel hub to the outboard wheel clamp, and the outboard wheel clamp extends from the outboard open ring to the outboard wheel.

18. The axle assembly of claim 17, wherein, The outboard wheel clamp has a mounting portion that defines a fastener hole that receives a stud extending from outboard open ring; and an outer flange that extends from an end of the mounting portion in the inboard direction, wherein the outer flange engages the outboard open ring and the outboard wheel.

19. The axle assembly of claim 18, wherein, The outer flange has a tapered surface facing away from the axis, the outboard wheel has a tapered surface facing toward the axis and engaging the tapered surface of the outer flange, wherein the tapered surface of the outer flange and the tapered surface of the outboard wheel are arranged in a non-parallel and non-perpendicular relationship to the axis.

20. The axle assembly of claim 18, wherein, A nut is tightened onto the stud, a wheel spacer extends from the outboard wheel to the inboard wheel, and tightening the nut pushes the outboard wheel clamp, the outboard wheel, the wheel spacer, and the inboard wheel in the inboard direction.

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