Vehicle driveline component with lubricated degasser

Abstract

A vehicle driveline component has a housing, a rotary power transfer system, a lubricant, and a lubrication deaerator. The housing defines a cavity and an oil pan. The rotary power transfer system is housed in the cavity and includes a plurality of gears in meshing engagement. The lubricant is contained in the oil pan and is used to lubricate the rotary power transmission system. The lubrication degasser is housed in the housing and has at least one matrix of degassing chambers extending between an upper surface and a lower surface. Each of the degassing chambers has a chamber inlet formed through the upper surface and a chamber outlet formed through the lower surface. And the part, between the chamber inlet and the chamber outlet, of each degassing chamber is conical.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Application No. 17 / 725,656, filed on April 21, 2022, the disclosure of which is incorporated herein by reference as if fully set forth herein. Technical Field

[0003] The present disclosure relates to a vehicle powertrain component having a lubricating degasser. Background Art

[0004] This section provides background information related to the present disclosure which is not necessarily prior art.

[0005] Vehicle driveline components (such as axle assemblies, transfer cases, power take-off units, and electric drive modules) have a rotary power transmission system that may include one or more sets of meshing gears. Internal lubrication of vehicle driveline components may be important for extending the life of vehicle driveline components and may help reduce wear, heat, and noise and vibration. Splash lubrication is relatively common in vehicle driveline components such as axle assemblies and power take-off units, while pressure-fed lubrication is commonly used in vehicle driveline components such as transfer cases and electric drive units. Splash lubrication requires that components of vehicle driveline components rotate through lubricants stored in an internal oil pan. The lubricant adheres to the rotating components as the rotating components rotate through the oil pan and is subsequently thrown from the rotating components due to centrifugal force. The thrown lubricant may be thrown or discharged to other components that require lubrication. In contrast, pressure-fed lubrication uses a pump to provide pressurized fluid to various components to be lubricated. The pump may discharge the pressurized lubricant to one or more passages within the vehicle driveline components.

[0006] Whether splash lubrication or pressure-fed lubrication is used, the lubricant in the vehicle transmission component frequently contacts various rotating parts before being discharged back to the oil pan. Due to the relatively high rotational speed of the rotating parts in the vehicle transmission component, air is very likely to be entrained into the lubricant when the rotating parts contact the lubricant and / or in the case where the lubricant is thrown from the rotating parts into the lubricant in the oil pan of the vehicle transmission component. Air entrained in the lubricant may reduce the film strength of the lubricant, which may reduce the performance of the lubricant, may increase the possibility of cavitation in the pump, which may increase the wear of the pump, and may reduce the rate at which heat is discharged into the lubricant. It is desired that the lubricant returning to the oil pan has as small a velocity as possible to promote the de-entrainment of air in the lubricant. In the case where the lubricant is thrown into the oil pan or surges with the lubricant in the oil pan, the thrown and / or surged lubricant increases the kinetic energy of the lubricant in the oil pan, which may impair the effectiveness of de-entraining air from the lubricant in the oil pan.

[0007] Accordingly, there is a need in the art for a lubricant degassing system that can be easily integrated into vehicle driveline components. Summary of the invention

[0008] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

[0009] In one form, the present disclosure provides a vehicle powertrain component comprising a housing, a rotary power transmission system, a lubricant, and a lubricating degasser. The housing has a plurality of inner surfaces, and the housing defines a cavity and an oil pan. The rotary power transmission system is contained in the cavity and comprises a plurality of gears in meshing engagement. The lubricant is contained in the oil pan and is used to lubricate the rotary power transmission system. The lubricating degasser is contained in the housing at a position to receive lubricant ejected from the rotary power transmission system. The lubricating degasser has at least one matrix of degassing chambers extending between an upper surface and a lower surface. Each of the degassing chambers has a chamber inlet formed through the upper surface and a chamber outlet formed through the lower surface. Each of the degassing chambers is tapered between its chamber inlet and its chamber outlet.

[0010] In some forms, the lubrication degasser has a plurality of matrices of degassing chambers, and the matrices of degassing chambers are vertically spaced apart from one another. Optionally, vertically adjacent matrices of degassing chambers are offset from one another so that the chamber outlets of each pair of vertically adjacent matrices are not vertically aligned with one another. Also optionally, each of the degassing chambers has a longitudinal axis, and each of the matrices are offset from one another so that the chamber inlets of each pair of vertically adjacent matrices are not vertically aligned with one another.

[0011] Optionally, the vertically adjacent matrices of degassing chambers are spaced apart by a plurality of legs, each leg having a first end and a second end, the first end being received in a leg hole formed in a first one of the matrices of degassing chambers, the second end being received in an associated one of the degassing chambers in a second one of the matrices of degassing chambers. Optionally, the second end of each of the legs contacts an inner surface of an associated one of the degassing chambers, and wherein at least one drainage channel is formed between the second end and the inner surface, the at least one drainage channel allowing the lubricant to drain around the second end to the chamber outlet of the associated one of the degassing chambers.

[0012] In some forms, each of the degassing chambers has a longitudinal axis, and wherein each of the degassing chambers has a non-circular cross-sectional shape in a section taken perpendicular to the longitudinal axis. Optionally, the non-circular cross-sectional shape is hexagonal.

[0013] In some forms, at least one of the plurality of gears rotates through the lubricant in the sump during operation of the vehicle driveline component.

[0014] In some forms, the vehicle powertrain component further includes an electric motor housed in the housing, the electric motor having a motor output shaft, and wherein one of the plurality of gears is coupled to the motor output shaft for rotation therewith.

[0015] In some forms, the rotary power transfer system includes a differential assembly.

[0016] In another form, the present disclosure provides a vehicle powertrain component, which includes a housing, a rotary power transmission system, a lubricant, and a lubricating degasser. The housing defines a cavity and an oil pan. The rotary power transmission system is contained in the cavity and includes a plurality of gears in meshing engagement. The lubricant is contained in the oil pan and is used to lubricate the rotary power transmission system. The lubricating degasser is contained in the cavity and includes a plurality of matrices of degassing chambers, the plurality of matrices being vertically spaced apart from each other. Each matrix of degassing chambers has a plurality of degassing chambers extending between an upper surface and a lower surface, each of the degassing chambers having a chamber inlet formed through the upper surface and a chamber outlet formed through the lower surface. Each of the degassing chambers is tapered between its chamber inlet and its chamber outlet. Vertically adjacent matrices of degassing chambers are offset from each other so that the chamber outlets of each pair of vertically adjacent matrices are not aligned with each other in the vertical direction. Each of the degassing chambers has a longitudinal axis, and each of the matrices are offset from each other so that the chamber inlets of each pair of vertically adjacent matrices are not aligned with each other in the vertical direction. Each of the degassing chambers has a non-circular cross-sectional shape in a section taken perpendicular to the longitudinal axis.

[0017] In some forms, the vertically adjacent matrices of degassing chambers are spaced apart by a plurality of legs, each leg having a first end and a second end, the first end being received in a leg aperture formed in a first one of the matrices of degassing chambers, the second end being received in an associated one of the degassing chambers in a second one of the matrices of degassing chambers. Optionally, the second end of each leg contacts an inner surface of an associated one of the degassing chambers, and wherein at least one drainage channel is formed between the second end and the inner surface, the at least one drainage channel allowing the lubricant to drain around the second end to the chamber outlet of the associated one of the degassing chambers.

[0018] In some forms, the non-circular cross-sectional shape is hexagonal.

[0019] In some forms, at least one of the plurality of gears rotates through the lubricant in the sump during operation of the vehicle driveline component.

[0020] In some forms, the vehicle powertrain component further includes an electric motor housed in the housing. The electric motor has a motor output shaft, and one of the plurality of gears is coupled to the motor output shaft for rotation therewith.

[0021] In some forms, the rotary power transfer system includes a differential assembly.

[0022] Further areas of applicability will become apparent from the description provided herein.The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

[0024] Figure 1 is a perspective view of an exemplary vehicle powertrain component constructed in accordance with the teachings of the present disclosure;

[0025] Figure 2 yes Figure 1 A longitudinal cross-sectional view of a vehicle powertrain component;

[0026] Figure 3 yes Figure 1 A transverse cross-sectional view of a vehicle powertrain component;

[0027] Figure 4 yes Figure 1 an exploded perspective view of a portion of a vehicle driveline component of FIG. 1 , illustrating a lubricating degasser in greater detail;

[0028] Figure 5 yes Figure 4 An exploded perspective view of a portion of a lubricating degasser;

[0029] Figure 6 is a cross-sectional view taken through a lubricated degasser illustrating legs mounted in a matrix of degassing chambers;

[0030] Figure 7 is a cross-sectional view of a portion of a lubrication degasser taken along a longitudinal axis of a plurality of degassing chambers;

[0031] Figure 8 is a perspective view of a leg of a lubrication degasser; and

[0032] Fig. 9 It is a longitudinal cross-section of the outrigger.

[0033] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. DETAILED DESCRIPTION

[0034] refer to Figures 1 to 3 , a vehicle drive train component constructed in accordance with the teachings of the present disclosure is generally indicated by reference numeral 10. In the example provided, the vehicle drive train component 10 is an electric drive unit, but it should be understood that the vehicle drive train component 10 may be an axle assembly, a transfer case, a power take-off unit, or any other type of vehicle drive train component. The vehicle drive train component 10 may include a housing 12, a rotary power transmission system 14, a lubricant 16, and a lubrication degasser 18.

[0035] refer to Figure 2 and Figure 3 , the housing 12 may have a plurality of inner surfaces 22, and may define a cavity 24 and an oil pan 26. The rotary power transmission system 14 is housed in the cavity 24 and includes at least one pair of meshing gears 30. Optionally, the rotary power transmission system 14 may include other components, such as a differential assembly. In the example shown, the rotary power transmission system 14 includes a transmission 32 and a differential assembly 34, and the vehicle driveline component 10 further includes an electric motor 36 housed in the housing 12 and driving the transmission 32. More specifically, the electric motor 36 has a motor output shaft 38, and the input gear 30a of the transmission 32 is coupled to the motor output shaft 38 to rotate therewith. The transmission 32 is configured to transmit rotary power between the input gear 30a and the output gear 30b. In its simplest form, the input gear 30a directly meshes with the output gear 30b. In the example provided, the transmission 32 is configured in the manner disclosed in commonly assigned U.S. Pat. No. 11,293,534, the disclosure of which is incorporated herein by reference as if fully set forth herein. It should be understood that the transmission 32 can be configured differently from the transmission shown and described herein. The differential assembly 34 includes a differential input member 40 that can be connected to the output gear 30b to rotate therewith and a pair of differential output members 42 (only one is shown) that can rotate relative to the differential input member 40. As shown, the differential input member 40 is a differential case that accommodates a differential gear set, and the differential output member 42 is a pair of side gears in the differential gear set. Each differential output member 42 can be connected to a corresponding output shaft (not shown) to rotate together about the output axis.

[0036] A predetermined volume of lubricant 16 may be disposed in an oil pan 26 in the housing 12. The output gear 30b may extend into the oil pan 26 such that during operation of the vehicle powertrain component 10, the output gear 30b rotates through the lubricant 16 in the oil pan 26. A shroud 50 may be disposed around the output gear 30b to limit the amount of lubricant 16 in the oil pan 26 that can contact the output gear 30b. Additionally or alternatively, a pump (not specifically shown) may be employed to draw the lubricant 16 from the oil pan 26 and provide a supply of pressurized lubricant 16 that may be directed through the housing 12 to lubricate various components such as bearings (not specifically shown) and gears, and / or to cool various components such as the stator 54 and rotor 56 of the motor 36. It will be appreciated that lubricant 16 that has been used to lubricate and / or cool various components of the vehicle transmission component 10 may be ejected from a rotating component (e.g., a gear or differential assembly 34 of the rotating power transmission system 14 ), and / or may be discharged onto the inner surface 22 of the housing 12 as the lubricant 16 returns to the sump 26 .

[0037] The lubrication degasser 18 is housed in a cavity 24 in the housing 12 and may optionally extend into the oil sump 26. The lubrication degasser 18 is disposed in a position configured to intercept the lubricant 16 that is returning to the oil sump 26. In this regard, the lubrication degasser 18 is positioned to intercept the lubricant 16 that is ejected from the rotary power transmission system 14 before it reaches and mixes with the lubricant 16 disposed in the oil sump 26.

[0038] refer to Figures 4 to 7 , the lubrication degasser 18 has at least one matrix 60 of degassing chambers 62. Each matrix 60 can be formed of a suitable material, such as a plastic material, and can be formed in a suitable process, such as injection molding. Each matrix 60 can have an upper surface 66 and a lower surface 68, and the degassing chambers 62 in the matrix 60 can extend between the upper surface 66 and the lower surface 68. Each degassing chamber 62 has a chamber inlet 70 formed through the upper surface 66 and a chamber outlet 72 formed through the lower surface 68. Each degassing chamber 62 has a longitudinal axis 78 and is tapered along its longitudinal axis 78 between its chamber inlet 70 and chamber outlet 72. Each degassing chamber 62 has a non-circular cross-sectional shape, such as a hexagonal cross-sectional shape, in a section taken perpendicular to its longitudinal axis 78.

[0039] In the example provided, the lubrication degasser 18 has a plurality of matrices 60 of degassing chambers 62 that are vertically spaced apart from one another. Preferably, the lubrication degasser 18 is configured such that vertically adjacent matrices 60 are offset from one another such that the chamber outlets 72 of each pair of vertically adjacent matrices 60 are not vertically aligned with one another. Also preferably, each matrix 60 is offset from one another such that the chamber inlets 70 of each pair of vertically adjacent matrices 60 are not vertically aligned with one another.

[0040] refer to Figures 6 to 9 , vertically adjacent matrices 60 may be spaced apart by a plurality of legs 80. Each leg 80 has a first end 82 and a second end 86, the first end 82 being received in a leg hole 84 formed in a first matrix 60 in the matrix 60, and the second end 86 being received in an associated one of the degassing chambers 62 in a vertically adjacent second matrix 60 in the matrix 60. Optionally, the second end 86 of each leg 80 may be configured to contact an inner surface 90 of an associated one of the degassing chambers 62, and cooperate with the inner surface 90 of the associated one of the degassing chambers 62 to form at least one discharge channel 92 extending between an outer surface of the second end 86 and the inner surface 90, thereby allowing the lubricant 16 entering the associated one of the degassing chambers 62 to be discharged around the second end 86 of the leg 80 to the chamber outlet 72 of the associated one of the degassing chambers 62.

[0041] refer to Figure 2 , Figure 3 and Figure 7 , lubricant 16 is thrown from one or more rotating components of the rotary power transmission system 14 and is received on the upper surface 66 of the first matrix 60 of the lubrication deaerator 18, where it can spread on the upper surface 66 of the first matrix 60 before being discharged into the chamber inlet 70 of the deaeration chamber 62 formed in the first matrix 60. The lubricant 16 entering the chamber inlet 70 can spread around the tapered surface of the deaeration chamber 62 before being discharged through the chamber outlet 72. The distribution of the lubricant 16 on the upper surface 66 of the first matrix 60 and on the tapered surface of the deaeration chamber 62 in the first matrix 60 spreads the lubricant 16 over a relatively large area and increases the time required for the discharged lubricant 16 to return to the oil sump 26. The spreading of the discharged lubricant 16 and the additional time required for the discharged lubricant 16 to return to the oil sump 26 facilitate de-entrainment of air from the discharged lubricant 16. Additionally, in the event that one or more larger bubbles (e.g., foam) are present in the lubricant 16 entering one of the degassing chambers 62, the tapered configuration of the degassing chamber 62 tends to retain the bubbles while allowing the lubricant 16 to exit the chamber outlet 72. Figure 7 , the discharged lubricant 16 is depicted by solid arrows, while the de-entrained air is depicted as circles.

[0042] Lubricant passing from the chamber outlets 72 of the degassing chambers 62 in the first matrix 60 can be directed either to the upper surface 66 of the vertically adjacent matrix 60, or to the oil pan 26 in the absence of a vertically adjacent matrix 60. It will be appreciated that the lubricant 16 will diffuse over the upper surface 66 of the vertically adjacent matrix 60 and over the conical surfaces of the degassing chambers 62 in the vertically adjacent matrix 60 before exiting through the chamber outlets 72 of the degassing chambers 62 in the vertically adjacent matrix 60. Accordingly, each vertically adjacent matrix 60 of degassing chambers 62 can repeatedly diffuse the discharged lubricant 16 and increase the time required for the discharged lubricant 16 to return to the oil pan 26, thereby further facilitating de-entrainment of air from the discharged lubricant 16.

[0043] It will be appreciated that the lubrication deaerator 18 significantly slows or calms the lubricant 16 in the sump 26 and protects the lubricant 16 in the sump 26 from being thrown or surged from rotating components of the rotary powertrain 14 .

[0044] For the purpose of illustration and description, the foregoing description of the embodiment has been provided. It is not intended to be exhaustive or limit the present disclosure. The individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but are interchangeable and can be used in selected embodiments where applicable, even if not specifically shown or described. It can also be changed in many ways. Such changes should not be considered as departing from the present disclosure, and all such modifications are intended to be included within the scope of the present disclosure.

Claims

1. A vehicle powertrain component, comprising: a housing defining the cavity and the oil sump, the housing having a plurality of interior surfaces; a rotary power transmission system received in the cavity, the rotary power transmission system comprising a plurality of gears in meshing engagement; a lubricant contained in the oil pan, the lubricant being used to lubricate the rotary power transmission system; as well as A lubricating degasser is housed in the housing at a position for receiving lubricant ejected from the rotary power transmission system, the lubricating degasser having at least one matrix of degassing chambers extending between an upper surface and a lower surface, each of the degassing chambers having a chamber inlet formed through the upper surface and a chamber outlet formed through the lower surface, each of the degassing chambers being tapered between its chamber inlet and its chamber outlet.

2. The vehicle powertrain component of claim 1, wherein the lubrication degasser has a plurality of matrices of degassing chambers, wherein the matrices of degassing chambers are vertically spaced apart from one another.

3. The vehicle powertrain component of claim 2, wherein vertically adjacent matrices of degassing chambers are offset from one another such that the chamber outlets of each pair of vertically adjacent matrices are not vertically aligned with one another.

4. The vehicle powertrain component of claim 3 wherein each of said degassing chambers has a longitudinal axis and wherein each of said matrices are offset from one another such that said chamber inlets of each pair of vertically adjacent matrices are not vertically aligned with one another.

5. A vehicle powertrain component as described in claim 1, wherein the vertically adjacent matrices of degassing chambers are separated by a plurality of legs, each of the legs having a first end and a second end, the first end being received in a leg hole formed in a first matrix of the matrices of degassing chambers and the second end being received in an associated one of the degassing chambers in a second matrix of the matrices of degassing chambers.

6. A vehicle powertrain component according to claim 5, wherein the second end of each of the legs contacts the inner surface of an associated one of the degassing chambers, and wherein at least one drainage channel is formed between the second end and the inner surface, the at least one drainage channel allowing the lubricant to be discharged around the second end to the chamber outlet of the associated one of the degassing chambers.

7. The vehicle powertrain component of claim 1, wherein each of the degassing chambers has a longitudinal axis, and wherein each of the degassing chambers has a non-circular cross-sectional shape in a section taken perpendicular to the longitudinal axis.

8. The vehicle powertrain component of claim 7, wherein the non-circular cross-sectional shape is hexagonal.

9. The vehicle powertrain component of claim 1, wherein at least one of the plurality of gears rotates through the lubricant in the oil sump during operation of the vehicle powertrain component.

10. The vehicle powertrain component of claim 1, further comprising a motor housed in the housing, the motor having a motor output shaft, and wherein one of the plurality of gears is coupled to the motor output shaft for rotation therewith.

11. The vehicle driveline component of claim 1 wherein said rotary power transfer system comprises a differential assembly.

12. A vehicle powertrain component, comprising: a housing defining the cavity and the oil sump; a rotary power transmission system received in the cavity, the rotary power transmission system comprising a plurality of gears in meshing engagement; a lubricant contained in the oil pan, the lubricant being used to lubricate the rotary power transmission system; as well as a lubricating degasser received in the cavity, the lubricating degasser having a plurality of matrices of degassing chambers, the plurality of matrices being vertically spaced apart from one another, each matrix of degassing chambers having a plurality of degassing chambers extending between an upper surface and a lower surface, each of the degassing chambers having a chamber inlet formed through the upper surface and a chamber outlet formed through the lower surface, each of the degassing chambers being tapered between its chamber inlet and its chamber outlet; wherein vertically adjacent matrices of degassing chambers are offset from one another so that the chamber outlets of each pair of vertically adjacent matrices are not vertically aligned with one another; wherein each of said degassing chambers has a longitudinal axis, and wherein each of said matrices are offset from one another such that said chamber inlets of each pair of vertically adjacent matrices are not vertically aligned with one another; and Each of the degassing chambers has a non-circular cross-sectional shape in a cross section taken perpendicular to the longitudinal axis.

13. A vehicle powertrain component as described in claim 12, wherein the vertically adjacent matrices of degassing chambers are separated by a plurality of legs, each of the legs having a first end and a second end, the first end being received in a leg hole formed in a first matrix of the matrices of degassing chambers, and the second end being received in an associated one of the degassing chambers in a second matrix of the matrices of degassing chambers.

14. A vehicle powertrain component according to claim 13, wherein the second end of each of the legs contacts the inner surface of an associated one of the degassing chambers, and wherein at least one drainage channel is formed between the second end and the inner surface, the at least one drainage channel allowing the lubricant to be discharged around the second end to the chamber outlet of the associated one of the degassing chambers.

15. The vehicle powertrain component of claim 12, wherein the non-circular cross-sectional shape is hexagonal.

16. The vehicle powertrain component of claim 12, wherein at least one of the plurality of gears rotates through the lubricant in the oil sump during operation of the vehicle powertrain component.

17. The vehicle powertrain component of claim 12, further comprising a motor housed in the housing, the motor having a motor output shaft, and wherein one of the plurality of gears is coupled to the motor output shaft for rotation therewith.

18. The vehicle driveline component of claim 12, wherein the rotary power transfer system includes a differential assembly.

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