Methods and systems for a drive axle

Patent metadata

Field	Value
Publication number	US-11313453-B2
Application number	US-201916600814-A
Country	US
Kind code	B2
Filing date	Oct 14, 2019
Priority date	Oct 14, 2019
Publication date	Apr 26, 2022
Grant date	Apr 26, 2022

Abstract

Methods and systems are provided for rear axle having a wet bath. In one example, a system comprises a pump configured to spin in a first direction to flow lubricant to a cooler and a second direction to entrain the lubricant with gas.

First claim

The invention claimed is:

1. A system, comprising:
a pump arranged in a lubricant sump of a rear axle, wherein the lubricant pump is configured to drive in a first direction to direct oil to an oil cooler and a second direction to entrain gas with lubricant in the sump.

2. The system of claim 1 , wherein the second direction is opposite the first direction, and wherein the second direction does not flow lubricant through the pump.

3. The system of claim 1 , wherein the pump is at least partially submerged in the lubricant sump, wherein the pump comprises a first passage submerged below lubricant, a second passage fluidly coupling the pump to a cooler arranged outside of the rear axle, and a third passage fluidly coupled to a head space above a top level of the lubricant.

4. The system of claim 3 , wherein lubricant flows through the first and second passages when the pump is operated in the first direction, wherein the lubricant flows to the cooler and is returned to the rear axle.

5. The system of claim 3 , wherein gas flows through the third passage and the first passage when the pump is operated in the second direction, wherein gas flows into lubricant arranged in the sump, wherein the gas is helium.

6. The system of claim 1 , further comprising a controller with computer-readable instructions stored on non-transitory memory thereof that when executed enable the controller to operate the pump in the first direction in response to a lubricant temperature exceeding an upper threshold temperature.

7. The system of claim 6 , wherein the instructions further enable the controller to operate the pump in the second direction in response to a lubricant temperature being less than a lower threshold temperature.

8. The system of claim 7 , wherein the lower threshold temperature corresponds to a cold-start of an engine included in a vehicle in which the rear axle is arranged, and wherein a temperature sensor is arranged in the lubricant sump.

9. The system of claim 7 , wherein the instructions further enable the controller to deactivate the pump in response to the lubricant temperature being between or equal to the lower and upper threshold temperatures.

10. A vehicle arrangement, comprising:
a rear axle configured to receive power from a powertrain including an engine, the rear axle comprising a hypoid gear arrangement arranged in a sump comprising a lubricant;
a pump coupled to the rear axle, wherein the pump is configured to entrain gas with the lubricant by operating in a reverse direction, wherein the pump is configured to flow the lubricant to a cooler arranged outside of the rear axle by operating in a forward direction; and
a controller with computer-readable instructions stored on non-transitory memory thereof that when executed enable the controller to:
operate the pump in the reverse direction when a lubricant temperature is less than a lower threshold temperature; and
operate the pump in the forward direction when the lubricant temperature is greater than an upper threshold temperature.

11. The vehicle arrangement of claim 10 , wherein the lubricant temperature is based on one or more of an ambient temperature, a vehicle speed, and a powertrain power.

12. The vehicle arrangement of claim 10 , wherein the pump is incorporated into a cover of the rear axle and completely submerged in the lubricant.

13. The vehicle arrangement of claim 10 , wherein the pump comprises a first passage configured to admit lubricant through the pump in the forward direction or expel gas into the lubricant in the reverse direction, the pump further comprises a second passage configured only to flow lubricant to a cooler arranged outside of the rear axle, the cooler comprising a return passage configured to return lubricant to the sump, wherein the pump further comprises a third passage configured to only admit gas to the pump.

14. The vehicle arrangement of claim 13 , wherein the first passage is at least partially submerged below a top level of the lubricant in the sump, and wherein the third passage is arranged completely above the top level of the lubricant in the sump.

15. The vehicle arrangement of claim 10 , wherein the lubricant is oil, and wherein the gas comprises a density less than or equal to a density of air, and wherein the pump is a positive displacement pump, and wherein the gas is methane.

16. A method, comprising:
activating a pump to operate in a first direction to flow lubricant through a first passage, to a second passage, and to a cooler in response to a lubricant temperature exceeding an upper threshold temperature, wherein the pump is arranged in a rear axle and the lubricant is arranged in a sump of the rear axle;
activating the pump to operate in a second direction opposite the first direction to flow gas through a third passage, to the first passage, and into the sump to mix with lubricant in response to the lubricant temperature being less than a lower threshold temperature; and
deactivating the pump in response to the lubricant temperature being between the upper threshold temperature and the lower threshold temperature.

17. The method of claim 16 , wherein the first passage is at least partially submerged in the lubricant arranged in the sump, and wherein the third passage is arranged above a top level of the lubricant arranged in the sump.

18. The method of claim 16 , wherein flowing gas through the first passage includes flowing gas in a direction opposite a direction of lubricant flow through the first passage.

19. The method of claim 16 , wherein the lubricant leaving the cooler is returned to the sump.

20. The method of claim 16 , wherein the pump is inside a housing of the rear axle.

Assignees

• Ford Global Tech Llc

Inventors

• Bidner David Karl

Classifications

• F16N39/08

  by diluting, e.g. by addition of fuel (lubrication of machines or engines in general, of internal-combustion engines F01M) · CPC title

• F16H57/045

  Lubricant storage reservoirs, e.g. reservoirs in addition to a gear sump for collecting lubricant in the upper part of a gear case · CPC title

• F16H57/0436 Primary

  Pumps · CPC title

• F16H57/0435

  Pressure control for supplying lubricant; Circuits or valves therefor · CPC title

• F16H57/0427

  on rotary parts, e.g. using baffles for collecting lubricant by centrifugal force · CPC title