WO2017040802A1

WO2017040802A1 - Rotary joint assembly

Info

Publication number: WO2017040802A1
Application number: PCT/US2016/049934
Authority: WO
Inventors: Edward E. Stuart
Original assignee: Dana Heavy Vehicle Systems Group, Llc
Priority date: 2015-09-04
Filing date: 2016-09-01
Publication date: 2017-03-09

Abstract

An assembly for a tire inflation system is provided. The assembly includes a rotary joint spindle (110) having a fluid conduit. A pair of rotary air seals (210A, 210B) are coupled with a portion of the rotary joint spindle. Adjacent to the rotary air seals, a bearing (150) having an inner race and an outer race is also coupled with the rotary joint spindle. Further, a bearing housing (170) is coupled with the outer race of the bearing. The bearing housing (170) includes a plurality of lugs (185) on an outer surface thereof. Additionally, a hub cap (190) having an inner surface with a plurality of lug slots (198) is positioned about the bearing housing so that the bearing housing lugs (185) are disposed in the hub cap lug slots (198).

Description

TITLE

ROTARY JOINT ASSEMBLY

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 62/214,498 filed on September 4, 2015, which is herein incorporated by reference in its entirety.

BACKGROUND

The presently disclosed subject matter relates to tire inflation systems. More particularly, the presently disclosed subject matter relates to a rotary joint assembly and the tire inflation system made therewith.

Tire inflation systems for vehicles provide a vehicle the versatility of adjusting tire pressures while the vehicle is stationary or in motion. For example, the tire pressure of one or more wheel assemblies in fluid

communication with a tire inflation system may be decreased to increase tire traction, or increased to reduce roiling resistance and increase the vehicle's fuel efficiency and tire fife-span, in addition, tire inflation systems increase a vehicle's maneuverability over differing terrains and reduce maintenance requirements.

Tire inflation systems often employ a rotary joint assembly to permit the rotating portions and non-rotating portions of the vehicle to communicate pressurized fluid effectively. Bearings in the rotary joint assembly can experience radial and axial loads during both assembly and operation, and dimensional tolerances can accumulate during the- assembly process. Thus, it would be desirable to provsde-a rotary joint assembly having a bearing housing that enabled both proper preload and optimal location of the bearing.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The accompanying drawings are incorporated herein as part of the specification and illustrate the principles of the presently disdosed subject matter. The advantages described above, as well as other advantages of the presently disclosed subject matter, will become readily apparent to those skilled in the art from the following detailed description when considered in the light of the accompanying drawings, in which:

FIG. 1 is a partially exploded perspective view of a portion of a rotary joint assembly according to an embodiment of the presently disclosed subject matter;

FIG. 2 is a partial cross-sectional view of a portion of a bearing housing and a bearing of the rotary joint assembly of FIG. 1 , having a rotary joint spindle removed for clarity;

FIG. 3 is a partial end view of a hub cap and a bearing housing of the rotary joint assembly of FIG. 1 , illustrating a clearance fit between the hub ca and the bearing housing;

FIG. 4 is a cross sectional view of a portion of a rotary joint assembly and a portion of a steer ax!e wheel end assembly according to an embodiment of the presently disclosed subject matter; and

FIG. 5 is a cross sectional view of a portion of a rotary joint assembly and a portion of a steer axle wheel end assembly according to another embodiment of the presently disclosed subject matter.

DETAILED DESCRIPTION OF EMBODIMENTS

It is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary, it is also to be understood that the specific assemblies and systems illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined herein. Hence, specific dimensions, directions or other physical characteristics relating to the embodiments disclosed are not to be considered as limiting, unless expressly stated otherwise. Also, although they may not be, like elements in various embodiments described herein may be commonly referred to with like reference numerals within this section of the application.

Certain embodiments of a rotary joint assembly 100 may be utilized with a steer axle wheel end assembly. However, the rotary joint assembly 100 is not limited to use with the steer axle wheel end assemblies described herein. The rotary joint assembly 100 disclosed herein may be utilized with, but is not limited to use with, military vehicies, off-highway vehicles, consumer vehicles, electric vehicies, autonomous or semi-autonomous driving vehicies, and manufacturing equipment.

In an embodiment, as illustrated in FIG. 4, a steer axie wheel end assembly comprises a spindle 105 disposed at its outboard end. The spindle 105 may extend from a steering knuckle (not depicted). The spindle 105 may be formed unitary with the steering knuckle, or be coupled therewith. The spindle 105 may comprise a spindle fluid passage 107 extending therethrough. In an embodiment, the spindle fluid passage 107 may be disposed concentric with a longitudinal axis of the spindle 105. The spindle fluid passage 107 may also be defined by any component or components, either within or without the spindle 105, or a combination thereof, where an outboard aperture of the spindl fluid passage 107 is generally adjacent to an outboard end of the spindle 105.

A hub (not depicted) may be rotatably mounted on and concentric with the spindle 105. A pair of bearings (not depicted) may be located between the hub and the spindle 105 to assist the hub's rotation with respect to the spindle 105. in addition, the hub may include a fastener flange. Fasteners ma be located through the fastener fiange for connecting the hub to a wheel (not depicted). The hub may also have a braking surface attached thereto; for example, a brake rotor or brake drum. The brake rotor may be located inboard of the hub and be coupled thereto by way of a plurality of fasteners.

As illustrated in FIG. 4, in an embodiment, a rotary joint spindle 110 may be coupled to the spindle 105. in this embodiment, the rotary joint spindle 0 is rotationally fixed. An inboard portion 115 of the rotary joint spindle 110 maybe located within the outboard end of the spindle 105. As illustrated in FIGS. 1 , 4, and 5, the rotary joint spindle 110 comprises a fluid conduit 120 extending therethrough and oriented generally parallel to and concentric with a

longitudinal axis 112 of the rotary joint spindle 10. The rotary joint spindle fluid conduit 120 is in fluid communication with the spindle fluid passage 107.

The rotary joint spindle 110 comprises the inboard portion 1 5, a center portion 125, and an outboard portion 130. In an embodiment, the center portion 125 has a greater outer diameter than the inboard portion 15, and the outboard portion 130 has a greater outer diameter than the center portion 125. The outboard portion 130 of the rotary joint spindle 1 0 may comprise a chamfered portion 130B at its outboard end.

in an embodiment the inboard portion 115 comprises a threaded portion 115A which engages a threaded portion of the spindle fluid passage 107. A bonded seal 35 ma be disposed around and concentric with the inboard portio 115 and abut a inboard surface of a spacer 140 and/or an inboard surface of the center portion 125. In addition, the bonded seal 135 may be positioned in a first portion 106A of a stepped annular groove formed in the outboard end of the spindle 105. The spacer 140 may be disposed around and concentric with the center portion 125 and abut an inboard surface of a bearing 150. Further, the spacer 140 inboard end may be positioned in a second portion 106B of the stepped annular groove formed in the outboard end of the spindle 105. However, in an embodiment, the spacer 140 inboard end may abut the outboard end of the spindle 105.

As illustrated in FIGS. 1 and 2, in an embodiment, the generally annular bearing 150 may be disposed about and concentric with the center portion 125 of the rotary joint spindle 110. Th bearing 150 may comprise an inner rac 155 disposed on and concentric with the outer diameter of the center portion 125 of the rotary joint spindle 110. In an embodiment, the inner race 155 is press-fit onto the rotary joint spindle 110 center portion 125. The bearing 150 further comprises an outer race 185. A bearing ball assembly 160 is disposed between the inner race 155 and the outer race 185. The bearing 150 may comprise any bearing having the necessary specifications to handle the loads of the particular assembly and service, including but not limited to bail bearings, roller bearings, and tapered roller bearings.

in an embodiment, a bearing housing 170 may be disposed on and concentric with the bearing 150. The bearing housing 170 is a generally annular member comprising an inner surface 175 and an outer surface 180. The inner surface 175 of the bearing housing 170 may be press-fit onto the outer race 165 of the bearing 150. The bearing housing 170 rotates with the outer race 165 during operatio of the rotary joint assembly 100. The outer surface 180 of the bearing housing 170 comprises a plurality of radially projecting lugs 185. in the embodiment depicted in FIG. 1_s the bearing housing 170 comprises three lugs 185; however, the bearing housing 170 may comprise any number of lugs 185. in another embodiment, the outer surface 180 of the bearing housing 170 comprises a plurality of splines (not depicted). in yet another embodiment, the plurality of splines disposed on the outer surface 180 includes a master spline. The lugs 185 or splines, and/or the bearing housing 1 0 annular member, may have chamfered inboard and/or outboard ends. Further, the bearing housing 170 may be manufactured out of any material, including, but not limited to, aluminum, aluminum alloy, steel, iron, titanium, carbon fiber, or any combination thereof.

The bearing housing 170 enables proper preload of the bearing 150 through suitable allowances for the interference fit of the outer bearing race 165 to the bearing housing 70, and the inner bearing race 155 to the rotary joint spindle 110. The bearing housing 170 further enables the bearing 150 to be optimally located, both axialiy and radially, to reduce misalignment and promote bearing life.

As illustrated in FIG. 5, in an embodiment, a pair of spaced apart rotary air seals 21 OA and 210B is disposed on and concentric with the outboard portion 130 of the rotary joint spindle 110. Additionally , the rotary air seals 21 OA and 210B may be press-fit into the inner surface 175 of the bearing housing 170. In an embodiment, the rotary air seal 21 OA comprises an inner surface 212A, an outer surface 211A, and a groove 215A between the two surfaces. The rotary air seal 210B comprises an inner surface 212B, an outer surface 211B, and a groove 215B between the two surfaces. The groove 215A of the outboard rotary air seal 21 OA faces an outboard direction and the groove 215B of the inboard rotary air seal 210B faces aainboard direction. A biasing member (not depicted) is located within both of the grooves 2 5A and 2158. in an embodiment, the biasing member may be a circular spring. The biasing members drive the rotary air seals 21 OA and 210B into engagement with the outer surface of the outboard portion 130 of the rotary joint spindle 10, and into engagement with the inner surface 175 of the bearing housing 170.

A pair of snap rings (not depicted) disposed on and concentric with the outboard portion 30 of the rotary joint spindle 110 may be utilized to ensure the Socation of the rotary air seals 21 OA and 21 OB. The snap rings may be secured in grooves (not depicted) in the inner surface 75 of the bearing housing 170. The rotary air seals 21 OA and 210B prevent fluid, such as but not limited to air, from leaking from the connection of the rotary joint spindle 110 to the bearing housing 170. If pressurized fluid enters the space between the two rotary air seals 21 OA and 210B, the pressurized fluid is vented to the

atmosphere via an opening 172 in the bearing housing 70 which is in fluid connection with a vent port 191 in a hu cap 190. A gasket (not depicted) may be utilized to create a seal between the opening 172 and the vent port 191.

As illustrated in FIGS. 1, 4, and 5, in an embodiment, the hub cap 190 may e disposed about and drivingiy engaged with the bearing housing 170 via engagement with the lugs 185. The hub ca 190 may comprise an inboard surface 196 and an outboard surface 97. In addition, the hub cap 90 may comprise an outer surface 192 and an inner surface 194. The inner surface 194 comprises a plurality of axialiy extending Sug slots 198. The lug slots 198 may extend from the inboard surface 96 to the outboard surface 197 of the hub cap 190. As illustrated in FIG. 3, the hub cap 190 and the bearing housing 1 0 are produced and assembled with a clearance fit between the outer surface 180 of the bearing housing 170 and the inner surface 194 of the hub cap 190. In addition, there is a clearance fit between the lugs 185 and the lug slots 198. During assembly, the hub cap 190 may be moved i an axial direction relative to the bearing 150, over the bearing housing 170, to account for dimensional tolerances and to address tolerance stack conditions. The hub cap 190 rotationalSy drives the bearing housing 170 and the bearing 150 outer race 165.

In an embodiment (not depicted), the bearing housing 170 comprises a plurality of axialiy extending lug slots (not depicted) disposed in the outer surface 180, the lug slots extending through at least the outboard surface of the -bearing housing 170. Conjointly, in this embodiment, the hub cap 190 comprises a plurality of axialiy extending lugs disposed on the inner surface 194 thereof, the lugs positioned to drivingiy engage the lug slots of the bearing housing 170. As illustrated in FIG. 5, in an embodiment, a banjo bolt 235 is coupled to a first external hub cap ri 275 of a hub cap 190 end portion 265. The banjo bolt 235 has a hollow body with an inboard end 240 and an outboard end 245. The banjo bolt 235 may comprise a threaded outer diameter at the inboard end 240 which engages with threads on the first externa! hub cap rsb 275. The hollow body of the banjo bolt 235 permits fluid to flow from the rotary joint spindle 110 into the banjo bolt 235. An aperture 250 is provided through the outboard end 245 of the banjo bolt 235. The aperture 250 is substantially located about an axis transverse the longitudinal axis of the banjo bolt 235, and connects the hollow interior of the banjo bolt 235 with a ring 255 disposed around and concentric with the banjo bolt 235. The ring 255 has a conduit 260 projecting from its exterior. A hose (not depicted), or other fluid conduit (not depicted), may be coupled with the outer surface of the conduit 260. The hose may extend to a tire (not depicted), and may be coupled therewith via connections, joints and/or valves as required.

The first external hub cap rib 275 may be integrally formed and unitary with the hub ca 190 end portion 265. The hub cap 190 end portion 265 may also comprise a second external hub cap rib 270 integrally formed and unitary with the first externa! hub cap rib 275. In an embodiment, the first external hub cap rib 275 and the second external hub cap rib 270 may be integrally formed and unitary with the hub cap 190. in another embodiment (not depicted), the first external hub ca rib 275 and the second external hub cap rib 270 are coupled to hub cap 190 by of a plurality of fasteners. Both the hub cap 190 and the external hub cap ribs 270 and 275 are constructed of a robust material, including, but not limited to, steel, aluminum, aluminum alloy, iron, titanium, carbon fiber, or any combination thereof.

In an embodiment illustrated in FIG. 4, the rotary air seals 2 OA and 210B are engaged with an outer surface 30A of the outboard portion 130 of the rotary joint spindle 110 and with an inner surface 220A of a rotary joint body 220. A pair of snap rings (not depicted) disposed about and concentric with the outboard portion 130 of the rotary joint spindle 110 may be utilized to ensure the location of the rotary air seals 21 OA and 210B. The sna rings may be secured in grooves (not depicted) in the inner surface 22 OA of the rotary joint body 220, The rotary air seals 210A and 2108 prevent fluid from leaking from the fluid connection of the rotary joint spindie 110 and the rotary joint body 220. If pressurized fluid enters the space between the two rotary air seals 2 OA and 210B, the pressurized fluid is vented to the atmosphere via an aperture 222 in the rotary joint body 220 in fluid connection with the opening 72 in the bearing housing 1 0 which is in fluid connection with the vent port 191 in the hub cap 190. A gasket (not depicted), or plurality thereof, may be utilized to create a seal between the opening 172 and the vent port 191 , and between the aperture 222 and the opening 172.

The rotary joint body 220 comprises a hollo body. The outer surface

225 of the rotary joint body 220 is coupled to the inner surface 175 of the bearing housing 170. in an embodiment, the rotary joint body 220 is press-fit into the inner surface 175 of the bearing housing 70. in an embodiment, the outboard portion 130 of the rotary joint spindie 110 extends at least partially into the interior of the rotary joint body 220. In an embodiment, the rotary joint body 220 and the rotary joint spindle 110 are not in direct contact with one another and they are separated by a gap.

The portions of the rotary joint body 220 and the rotary joint spindle 110 which overlap are coaxial. In addition, the inboard end of the rotary joint body 220 is disposed adjacent the outboard end 151 of the bearing 150. The outboard end of the rotary joint body 220 may have an outer surface 230 comprising a plurality of facets. For example, a cross section of the outer surface 230 may have a hexagonal geometry.

The banjo bolt 235 may be coupled to the outboard end 221 of the rotary joint body 220. The rotary joint body 220 outboard end 221 is concentric about the inboard end 240 of the banjo bolt 235. The banjo bolt 235 may comprise a threaded outer surface at the inboard end 240 of the banjo bolt 235 which engages with threads on the inner diameter of the outboard end 221 of the rotary joint body 220. The hollow body of the banjo bolt 235 permits fluid to flow from the rotary joint spindle 110, through the rotary joint body 220, and into the banjo bolt 235.

A banjo boit aperture 250 connects the hollow interior of the banjo bolt 235 with a ring 255 disposed around and concentric with the banjo bolt 235. The ring 255 has a conduit 260 projecting from its exterior and a hose (not depicted) attached to the outer surface of the conduit 260 extending to a tire (not depicted), such as through other connections, joints and/or valves as required.

As -illustrated in FIG. 4, in an embodiment, a portion of the banjo bolt 235 and a portion of the rotary joint body 220 are at least partially housed within the second external hub cap rib 270. The second exiernai hub cap rib 270 projects from the hub cap 190 in an outboard direction and extends circumferentia!ly about the banjo boft 235 and a portion of the rotary joint body 220. However, a gap is provided in the second external hub cap rib 270 to accommodate the hose extending from the banjo bolt conduit 260. The second external hub cap rib 270 protects the banjo bolt 235, the ring 255 and conduit 260, and the connection of the hose at the conduit 260, from damage.

While various embodiments have been described above, it should be understood that they have been presented by way of example, and not limitation. It will be apparent to persons skilled in the relevant arts that the disclosed subject matter may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The embodiments described above are therefore to be considered in all respects as illustrative, not restrictive.

Claims

What is claimed is:

1. An assembly for a tire inflation system, comprising:

a rotary joint spindle having a fluid conduit extending therethrough;

a pair of spaced apart rotary air seals disposed about and sealingly coupled with said rotary joint spindle;

a bearing coupied with said rotary joint spindle adjacent said pair of rotary air seals, said hearing having an inner race and an outer race;

a bearing housing coupled with said bearing outer race for rotation therewith, said bearing housing, comprising an outer surface having a plurality of lugs disposed thereon; and

a hub cap disposed about said bearing housing, wherein said hub cap comprises an inner surface having a pluralit of slots, and said bearing housing lugs are disposed in said siots.

2. The assembly for a tire inflation system according to claim 1 , wherein said rotary joint spindle comprises:

an inboard portion, a center portion, and an outboard portion,

said outboard portion having a greater diameter than said center portion, said center portion having- a greater diameter than said inboard portion, and

said inboard portion comprising a threaded section.

3. The assembly for a tire inflation system according to claim 2, further comprising:

a spindle having a fluid passage extending therethrough, wherein a portion of said spindle fluid passage is threaded; and

said rotary joint spindle inboard end is in threaded engagement with said spindle fluid passage.

4. The assembly for a tire inflation system according to claim 1 , further comprising:

a banjo bolt disposed through and coup!ed with said hub cap, wherein said banjo bolt is in fluid communication with said rotary joint spindle fluid conduit.

5. The assembly for a tire inflation system according to claim 4, wherein said hub cap further comprises:

an end portion having a first ri and a second rib, wherein said second rib has a larger diameter than said first rib, and said second rib is disposed about and concentric with said first rib; and

said banjo bolt is disposed through and coupled with said hub cap first rib.

6. The assembly for a tire inflation system according to claim 1 , wherein:

said bearing housing defines an aperture therethrough substantially transverse a longitudinal axis of said bearing housing;

said hub cap comprises a vent port in fluid communication with an interior surface of said hub cap and an exterior surface of said hub cap; and said bearing housing aperture and said hub cap vent port are in fluid communication.

7. The assembly for a tire inflation system according to claim 1 , wherein:

said bearing housing lugs comprise chamfered ends.

8. The assembly for a tire inflation system according to claim 1, further comprising:

a clearance fit between said hub cap and said bearing housing, wherein said clearance fit comprises a space defined by said hub cap inner surface and bearing housing outer surface.

9. The assembly for a tire inflation system according to claim 1 , further comprising:

a steering knuckie spindle having a fluid passage therethrough, wherein said steering knuckie spind!e is coupled with said rotary joint spindle and said fluid conduit is in fluid communication with said fluid passage; and

a spacer disposed about said rotary joint spindle, wherein a first end of said spacer abuts said bearing, and a second end of said spacer abuts said steering knuckle spindle.

10. The assembly for a tire inflation system according to claim 9, further comprising:

a groove defined by an outboard end of said steering knuckle spindle; and

a bonded seal disposed about said rotary joint spindle, and located at teas! partially in said groove.

11. The assembly for a tire inflation system according to claim 1 , wherein:

said pair of spaced apart rotary air seals are sealingly coupled with said bearing housing.

12. The assembly for a tire inflation system according to claim 1 , further comprising:

a rotary joint bod at least partially disposed about said rotary joint spindle, and

said rotary joint body is sealingly coupled with an outer surface of said rotary air-seals.

13. The assembly for a tire inflation system according to claim 12, wherein said rotary joint body comprises:

an outer surface coupled with said bearing housing for rotation therewith;

an aperture through an inner and said outer surface of said rotary joint body, and

said aperture in fluid communication with an opening through said bearing housing and a vent port through said hub cap, wherei said vent port is in fluid communication with said atmosphere.

14. The assembly for a tire inflation system according to claim 13, further comprising:

a banjo bolt coupled with said rotary joint body, wherein said banjo bolt is in fluid communication with said rotary joint spindle fluid conduit.

15. The assembly for a tire inflation system according to claim 12, wherein said rotary joint body comprises:

an outboard end having an outer surface comprising a plurality of facets.