# US 11,077,726 B2 · Front axle rotary joint assembly and the tire inflation system made therewith > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,077,726 B2 - Document ID: US11077726B2 - Status: Granted - Kind: B2 - Application number: 16/024,148 - Filed: 2018-06-29 - Published: 2019-01-03 - Granted: 2021-08-03 - Earliest claimed: 2017-06-30 - Assignees: Dana Automotive Systems Group, LLC - Applicants: Dana Automotive Systems Group, LLC - Inventors: Christopher D. Blessing; Seth A. Metzger; Jason M. Sidders - Web page: https://patentgrep.com/patent/US11077726B2 ## CPC - B60C 23/003: {comprising rotational joints between vehicle-mounted pressure sources and the tyres} - B60C 29/06: Accessories for tyre-inflating valves, e.g. housings, guards, covers for valve caps, locks, not otherwise provided for {(B60C23/0496 takes precedence; tools for screwing and unscrewing valve caps B25B27/0057; pump connectors F04B33/005)} - B60C: VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES ## Abstract An axle assembly having a constant shaft disposed at least partially through a bearing hub assembly. The constant shaft defines a fluid conduit therethrough. A steering knuckle is disposed at least partially about the constant shaft. The axle assembly may include a bearing spacer disposed about the constant shaft, the bearing spacer being disposed at least partially axially between the bearing hub assembly and the steering knuckle. Additionally, a first rotary seal and a second rotary seal may be disposed radially between the bearing spacer and the constant shaft. The first and second rotary seals may at least partially define a fluid chamber in fluid communication with the constant shaft fluid conduit. Further, a port may be disposed through the bearing spacer, wherein the port is in fluid communication with the fluid chamber. ## Claims ### Claim 1 An axle assembly, comprising: a bearing hub assembly; a constant shaft disposed at least partially through said bearing hub assembly, wherein said constant shaft defines a first fluid conduit therethrough, and wherein said constant shaft includes: a spindle portion; a spacer portion disposed axially adjacent to said spindle portion; and a yoke portion disposed axially adjacent to said spacer portion, wherein said spacer portion comprises a greater diameter than said spindle portion; a steering knuckle disposed at least partially about said constant shaft; a bearing spacer disposed about said constant shaft, wherein said bearing spacer is disposed at least partially axially between said bearing hub assembly and said steering knuckle; a sleeve disposed at least partially about said constant shaft spacer portion, wherein a first and a second rotary seal is in sealing engagement with said sleeve, and wherein said sleeve includes: a radially inner surface at least partially coupled with said constant shaft spacer portion; and an annular recess defined by said radially inner surface, wherein said annular recess and said constant shaft spacer portion define a first fluid chamber in fluid communication with said first fluid conduit; the first rotary seal disposed radially between said bearing spacer and said constant shaft; the second rotary seal disposed radially between said bearing spacer and said constant shaft, wherein said first and second rotary seals at least partially define a second fluid chamber influid communication with said first fluid conduit; and a port disposed through said bearing spacer, wherein said port is in fluid communication with said second fluid chamber. ### Claim 2 (depends on 1) The axle assembly according to claim 1, wherein said constant shaft further comprises: said first fluid conduit disposed through a radially outer surface of said constant shaft; and a second fluid conduit disposed through an outboard end of said constant shaft, wherein said second fluid conduit is disposed coaxially with said constant shaft, and wherein said second fluid conduit is in fluid communication with said first fluid conduit. ### Claim 3 (depends on 1) The axle assembly according to claim 1, further comprising: a spacer disposed axially between said first rotary seal and said second rotary seal, wherein said spacer defines one or more apertures therethrough. ### Claim 4 (depends on 1) The axle assembly according to claim 1, wherein said bearing hub assembly further comprises: an outer bearing flange at least partially disposed radially within said bearing spacer. ### Claim 5 (depends on 1) The axle assembly according to claim 1, wherein said bearing spacer further comprises: a first radially outer surface, wherein said first radially outer surface is disposed at least partially radially within said steering knuckle; and a second radially outer surface having a greater diameter than said first radially outer surface. ### Claim 6 (depends on 5) The axle assembly according to claim 5, wherein said bearing spacer port is disposed through said second radially outer surface. ### Claim 7 (depends on 6) The axle assembly according to claim 6, wherein said bearing spacer port further comprises: a first fluid conduit disposed radially through said second radially outer surface; and a second fluid conduit disposed through said bearing spacer, whereby said first fluid conduit of the bearing spacer is in fluid communication with said second fluid chamber. ### Claim 8 (depends on 6) The axle assembly according to claim 6, wherein said bearing spacer port is disposed at an acute angle to a longitudinal axis of said bearing spacer. ### Claim 9 (depends on 5) The axle assembly according to claim 5, wherein said bearing spacer further comprises: a radially inward extending flange disposed at an inboard end of said bearing spacer. ### Claim 10 (depends on 1) The axle assembly according to claim 1, further comprising: a snap ring at least partially disposed in a radially inner surface of said bearing spacer, wherein said snap ring is disposed outboard of said first rotary seal. ### Claim 11 (depends on 1) The axle assembly according to claim 1, further comprising: a tube coupled with said bearing spacer port, whereby said bearing spacer port is in fluid communication with a fluid reservoir. ### Claim 12 An axle assembly, comprising: a steering knuckle, comprising: a bearing spacer formed unitary with said steering knuckle; a brake spacer formed unitary with said steering knuckle; one or more dust shield spacers formed unitary with said steering knuckle; a constant shaft disposed at least partially through said steering knuckle, wherein said constant shaft defines a fluid conduit therethrough, and wherein said constant shaft includes: a spindle portion; a spacer portion disposed axially adjacent to said spindle portion; and a yoke portion disposed axially adjacent to said spacer portion, wherein said spacer portion comprises a greater diameter than said spindle portion; a sleeve disposed at least partially about said constant shaft spacer portion, wherein a first and a second rotary seal is in sealing engagement with said sleeve, and wherein said sleeve includes: a radially inner surface at least partially coupled with said constant shaft spacer portion; and an annular recess defined by said radially inner surface, wherein said annular recess and said constant shaft spacer portion define a first fluid chamber in fluid communication with said fluid conduit the first rotary seal disposed radially between said bearing spacer and said constant shaft; the second rotary seal disposed radially between said bearing spacer and said constant shaft, wherein said first and second rotary seals at least partially define a second fluid chamber in fluid communication with said fluid conduit; and a port disposed through said bearing spacer, wherein said port is in fluid communication with said second fluid chamber.