Axle assembly with purge reservoir for air dryer
View Patent ↗An axle assembly includes an axle beam with an inner cavity that forms a purge reservoir. The purge reservoir is fluidly connected to an air dryer with a purge valve. The air dryer is part of a vehicle air supply system that supplies air from a compressor to storage reservoirs for vehicle systems such as suspension and braking systems. The air dryer includes a desiccant material that removes moisture from compressed air. During a compression cycle, air flows through the air dryer to the storage reservoirs and to the purge reservoir. Once a desired pressure level in the storage reservoirs is achieved, the compressor is unloaded and a purge command is generated to open the purge valve. When the purge valve is opened, air stored within the purge reservoir flows back through the air dryer to regenerate the desiccant material.
1. A vehicle air supply system comprising:
an air dryer including a purge valve; and
an axle component including a purge reservoir wherein air from said purge reservoir is communicated to said air dryer via said purge valve in response to a purge command.
2. The vehicle air supply system according to claim 1 wherein said axle component comprises an axle beam.
3. The vehicle air supply system according to claim 2 wherein said axle beam includes a pneumatically sealed inner cavity that forms said purge reservoir.
4. The vehicle air supply system according to claim 2 wherein said axle beam comprises a hollow tube extending between laterally spaced wheel components, said hollow tube having an inner surface defining said purge reservoir.
5. The vehicle air supply system according to claim 1 wherein said air dryer includes an inlet adapted for fluid connection to a compressor and at least one outlet adapted for fluid connection to at least one air supply reservoir.
6. The vehicle air supply system according to claim 5 wherein the compressor supplies air to said air dryer through said inlet during a compression cycle and wherein said air dryer supplies air to the at least one air supply reservoir through the at least one outlet during the compression cycle until a desired pressure level is achieved in the at least one air supply reservoir.
7. The vehicle air supply system according to claim 6 wherein a compressor unloading cycle is initiated when the desired pressure level is achieved and wherein the purge command is generated during the compressor unloading cycle to open said purge valve.
8. The vehicle air supply system according to claim 7 wherein said purge reservoir is filled with air from said air dryer during each compression cycle and is exhausted through said air dryer to atmosphere during each compressor unloading cycle.
9. An axle assembly comprising:
an axle beam extending between laterally spaced wheel components; and
a purge reservoir formed within said axle beam wherein air is stored in said purge reservoir and is in fluid communication with an air dryer during a purge cycle.
10. The axle assembly according to claim 9 wherein said axle beam comprises an axle housing having an inner cavity that forms said purge reservoir.
11. The axle assembly according to claim 10 wherein said inner cavity comprises a pneumatically sealed inner cavity that defines a fluid volume and wherein all of the fluid volume is exhausted to atmosphere through the air dryer during each purge cycle.
12. The axle assembly according to claim 10 wherein said inner cavity defines a first fluid volume and wherein said axle beam includes at least one volume reducing component received within said inner cavity to form a pneumatically sealed cavity defining a second fluid volume that is less than said first fluid volume and wherein said second fluid volume is exhausted to atmosphere through the air dryer during each purge cycle.
13. The axle assembly according to claim 12 where said at least one volume reducing component comprises a resilient bladder.
14. The axle assembly according to claim 12 wherein said at least one volume reducing component comprises a lightweight material that at least partially fills said inner cavity to reduce said first fluid volume to said second fluid volume.
15. The axle assembly according to claim 10 wherein said inner cavity comprises a pneumatically sealed inner cavity that defines a fluid volume and including a control valve in fluid communication with said fluid volume and positioned upstream from said pneumatically sealed inner cavity and downstream from an air dryer purge valve and wherein said control valve exhausts said fluid volume to a predetermined pressure level during each purge cycle, said predetermined pressure level being different than atmospheric pressure.
16. The axle assembly according to claim 9 including at least one fluid connection fluidly connecting said purge reservoir to a purge valve that is in fluid communication with the air dryer and wherein air is supplied to said purge reservoir through said purge valve during a compression cycle and wherein air is exhausted from said purge reservoir through said purge valve to atmosphere during each purge cycle.
17. The axle assembly according to claim 16 wherein said axle beam includes an inlet port fluidly connected to said at least one fluid connection and a drain port that allows liquid to be drained from said purge reservoir.
18. The axle assembly according to claim 9 wherein the axle assembly comprises a non-drive steer axle.
19. A method for purging air from an air dryer comprising:
(a) generating a purge command; and
(b) exhausting air from a purge reservoir formed within an axle beam through the air dryer in response to the purge command.
20. The method according to claim 19 including providing the axle beam with a pneumatically sealed inner cavity to form the purge reservoir, providing at least one inlet port in the axle beam, and fluidly connecting the at least one inlet port to a purge valve supported by the air dryer.