Electric drive unit with integrated variable flow low pressure oil cooling system

Abstract

An electric drive unit has an electric motor, a differential assembly, a transmission that transmits rotational power from the electric motor to the differential assembly, and a pair of output shafts rotatably coupled to respective differential output members of the differential assembly. The electric drive unit is configured to provide low cost, reliable cooling and / or lubrication to various components of the electric drive unit.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Application No. 17 / 705,433, filed on March 28, 2022, the disclosure of which is incorporated herein by reference as if fully set forth herein. Technical Field

[0002] The present disclosure relates to an electric drive unit. Background Art

[0003] This paragraph provides background information about the present disclosure which is not necessarily prior art.

[0004] Electric drive units combine the electric motor, transmission and differential assembly into a single component that can be relatively easily integrated into a vehicle by OEMs. OEMs are increasingly interested in electric drive units not only as a means of moving away from conventional drivetrains that use an internal combustion engine as the sole source of propulsion power, but also as a convenient and relatively low-cost means for electrifying vehicle drivetrains.

[0005] The electric motor of an electric drive unit can generate a large amount of heat during operation of the electric drive unit. Various concepts have been developed to cool the electric motor of the electric drive unit. These concepts generally use a lubricant that flows through the rotor and stator of the electric motor at a relatively high pressure to cool the electric motor. In addition, the high-pressure lubricant is also used to lubricate various components of the electric drive unit, such as various bearings. One disadvantage of these concepts is their relative complexity and cost. Therefore, there is a need for an electric drive unit with a cooling and lubrication system that is less complex and less costly while providing robust and reliable cooling and lubrication. Summary of the invention

[0006] This paragraph provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

[0007] In one form, the present disclosure provides an electric drive unit, which includes a housing assembly, an electric motor, a differential assembly, a first output shaft and a second output shaft, a transmission and a fluid pump. The housing assembly defines a first chamber, a second chamber, a reservoir and an upper reservoir. The reservoir is connected to the first chamber in fluid communication, and the upper reservoir is separated from the reservoir and the first chamber. The electric motor is received in the first chamber and includes a stator, a rotor and a motor output shaft. The stator has a stator core fixedly connected to the housing assembly and a plurality of windings. The rotor is received in the stator and can rotate around a rotation axis. The motor output shaft is connected to the rotor to rotate with the rotor around the rotation axis. The differential assembly is disposed in the second chamber and includes a differential input component rotatable relative to the housing assembly, and a first differential output component and a second differential output component rotatable relative to the differential input component. The first output shaft is connected to the first differential output component to rotate with the first differential output component. The second output shaft is connected to the second differential output component to rotate with the second differential output component. The transmission is received in the second cavity and is configured to transmit rotational power between the motor output shaft and the differential input component. The fluid pump is configured to extract lubricant from the reservoir and provide a lubricant flow. At least a portion of the lubricant flow is discharged into the upper reservoir. The housing assembly defines a plurality of first lubricant supply channels and a plurality of second lubricant supply channels. Each of the first lubricant supply channel and the second lubricant supply channel is a conduit that allows the lubricant in the upper reservoir to be discharged to the associated components of the electric drive unit due to gravity to lubricate and / or cool the associated components. The first lubricant supply channel intersects with the upper reservoir at an associated position less than or equal to the first height dimension, and the second lubricant supply channel intersects with the upper reservoir at a corresponding position greater than or equal to the second height dimension. The second height dimension is relatively greater than / higher than the first height dimension.

[0008] In another form, the present disclosure provides an electric drive unit, which includes a housing assembly, a motor, a differential assembly, a first output shaft and a second output shaft, a transmission and a lubricant. The housing assembly defines a first cavity, a second cavity and a reservoir. The motor is received in the first cavity and includes a stator, a rotor and a motor output shaft. The stator has a stator core and a plurality of windings fixedly coupled to the housing assembly. The rotor is received in the stator and can rotate around a rotation axis. The motor output shaft is coupled to the rotor so as to rotate with the rotor around the rotation axis. The differential assembly is disposed in the second cavity and includes a differential input component rotatable relative to the housing assembly, and a first differential output component and a second differential output component rotatable relative to the differential input component. The first output shaft is coupled to the first differential output component to rotate with the first differential output component. The second output shaft is coupled to the second differential output component to rotate with the second differential output component. The transmission is received in the second cavity and is configured to transmit rotational power between the motor output shaft and the differential input component. A lubricant is disposed in the reservoir and is configured to cool and / or lubricate components of the electric drive unit. When the electric drive unit is operated in a nominal orientation, the lubricant establishes a predetermined lubricant level in the reservoir. The reservoir intersects the first cavity such that a portion of the stator is disposed in the lubricant within the reservoir. The predetermined lubricant level in the reservoir is spaced apart from the rotor such that the rotor does not spin through the lubricant in the reservoir when the electric drive unit is operated in the nominal orientation.

[0009] 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

[0010] 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.

[0011] Figure 1 is a perspective view of an exemplary electric drive unit constructed in accordance with the teachings of the present disclosure; Figure 2 yes Figure 1 A longitudinal sectional view of an electric drive unit; Figure 3 is along Figure 2 a cross-sectional view taken along line 3-3 of ; Figure 4 yes Figure 1 an exploded perspective view of a portion of an electric drive unit showing the transmission and differential assembly in greater detail; Figure 5 and Figure 6 yes Figure 1 A side cross-sectional view of an electric drive unit showing parts of the cooling and lubrication system in more detail; Figure 7 yes Figure 1 a perspective cross-sectional view of a portion of an electric drive unit of FIG. 1 with a housing assembly cut away to better illustrate an upper reservoir in the housing assembly and various passages and a lubricant supply passage coupled in fluid communication with the upper reservoir; Figure 8 It passes through Figure 1 a cross-sectional view of an electric drive unit taken in, showing a plurality of lubricant supply passages; Fig. 9 It is integrated into the vehicle environment Figure 1 A schematic diagram of an electric drive unit in FIG. Fig.10 yes Figure 1 A schematic cross-sectional view of an electric drive unit; Fig.11 yes Figure 1 A cross-sectional view of an electric drive unit showing lubricating oil being distributed through the electric drive unit for lubrication and cooling purposes; and Fig.12 is a schematic diagram of a second electric drive unit constructed in accordance with the teachings of the present disclosure.

[0012] Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. DETAILED DESCRIPTION

[0013] See also Figure 1 and Figure 2 An exemplary electric drive unit constructed in accordance with the teachings of the present disclosure is generally indicated by reference numeral 10. The electric drive unit includes a housing assembly 12, an electric motor 14, a transmission 16, a differential assembly 18, respective first and second output shafts 20 and 22, a control unit 24, and a cooling and lubrication system 26.

[0014] exist Figure 2 , the housing assembly 12 may be formed of a plurality of housing members or components that may be assembled to one another to form a first chamber 30, a second chamber 32, and an upper reservoir 34. The motor 14 may be received in the first chamber 30, while the transmission 16 and the differential assembly 18 may be received in the second chamber 32. The first chamber 30 may define a reservoir 36 configured to contain a quantity of lubricant for lubricating and cooling the various components of the electric drive unit 10. A lubricant supply passage (not specifically shown) may be formed through an inner wall of the housing assembly 12 to fluidly couple the second chamber 32 to the reservoir 36. The upper reservoir 34 may be isolated from the first chamber 30 and the second chamber 32 by a wall member 38. A cover C ( Figure 6 ) to close the top side of the upper reservoir 34. Figure 6) may be sealingly coupled to the housing assembly 12 via a plurality of threaded fasteners (not shown) and washers (not shown).

[0015] The electric motor 14 includes a stator 40, a rotor 42, and a motor output shaft 44. The stator 40 includes a stator core 50 and a plurality of field windings 52 wound around the stator core 50. The rotor 42 is received in the stator 40 and is rotatable relative to the stator about a rotation axis 56. The motor output shaft 44 is a hollow tubular structure that is received within the rotor 42 and rotationally coupled to the rotor 42. The motor output shaft 44 is supported by a pair of motor output shaft bearings 58 for rotation relative to the housing assembly 12.

[0016] See also Figure 2 , Figure 3 and Figure 4 , the transmission 16 is configured to transmit rotational power between the motor output shaft 44 and the differential assembly 18. In the example provided, the transmission 16 includes an input pinion 60, a first intermediate gear 62, a second intermediate gear 64, and an output gear 66. The input pinion 60 is coupled to the motor output shaft 44 to rotate with the motor output shaft. The first intermediate gear 62 is rotatable around a second rotation axis 68 offset from the rotation axis 56 and meshes with the input pinion 60. The second intermediate gear 64 is coupled to the first intermediate gear 62 to rotate with the first intermediate gear around the second rotation axis 68. The output gear 66 meshes with the second intermediate gear 64 and is rotatable around the rotation axis 56. It will be appreciated that a set of intermediate gear bearings 70 can be used to support the first intermediate gear 62 and the second intermediate gear 64 to rotate relative to the housing assembly 12. Optionally, a parking lock gear 72 is rotatably coupled to the first intermediate gear 62 and the second intermediate gear 64. The park lock gear 72 is engageable by a pawl (not specifically shown) on a park lock actuator 74 that is fixedly coupled to the housing assembly 12 to inhibit rotation of the first and second intermediate gears 62 , 64 , and thereby the output gear 66 .

[0017] See also Figure 2 and 4, the differential assembly 18 is configured to transmit rotational power from the output gear 66 of the transmission 16 to the first output shaft 20 and the second output shaft 22, and to allow a speed difference between the first output shaft 20 and the second output shaft 22. In this regard, the differential assembly 18 can have a differential input member that can be rotatably coupled to the output gear 66, and a pair of differential output members that can rotate relative to the differential input member. The differential assembly 18 can be constructed in any desired manner, but in the example provided, the differential assembly 18 includes a differential case 80, corresponding first and second side gears 82 and 84, and a plurality of differential pinions 86. The differential case 80 (in the example provided, the differential input member) is coupled to the output gear 66 to rotate with the output gear around the axis of rotation 56. A pair of differential bearings 90 can support the differential case 80 to rotate relative to the housing assembly 12. The first and second side gears 82 and 84 are received in the differential case 80 and can rotate relative to the differential case 80 around the axis of rotation 56. Each of the differential pinions 86 meshes with the first side gear 82 and the second side gear 84, is coupled to the differential case 80 to rotate with the differential case about the rotation axis 56, and is rotatable relative to the differential case 80 about an axis perpendicular to the rotation axis 56. In the example provided, the number of differential pinions 86 is two (i.e., there are two differential pinions 86 in the example provided), and is rotatably received on a cross pin 94 mounted to the differential case 80.

[0018] The first output shaft 20 is received through a first axial end of the housing assembly 12, the motor output shaft 44, the input pinion 60, and an axial end of the differential case 80, and is drivingly engaged to the first side gear 82. The second output shaft 22 is received through a second, opposite axial end of the housing assembly 12, a second, opposite axial end of the differential case 80, and is drivingly engaged to the second side gear 84. Retaining rings may be employed to axially secure the first output shaft 20 and the second output shaft 22 to the first side gear 82 and the second side gear 84, respectively. If desired, an output shaft bearing 98 may be employed to support the first output shaft 20 and / or the second output shaft 22 for rotation relative to the housing assembly 12 about the rotation axis 56. In the example provided, only the first output shaft 20 is supported by the output shaft bearing 98.

[0019] Back to Figure 1 and Figure 2 The control unit 24 may include an inverter (not specifically shown), a motor controller (not specifically shown), power terminals (not specifically shown), and other control hardware required to provide power and control the operation of the motor 14 and the cooling and lubrication system 26. The control unit 24 may be mounted to the outside / exterior surface of the housing assembly 12.

[0020] See also Figure 1 and Figure 5, the cooling and lubrication system 26 is configured to cool and lubricate various components of the electric drive unit 10, and includes a fluid pump 100 and a heat exchanger 102. The fluid pump 100 can be mounted to a pump support 110 incorporated into the housing assembly 12. In the example provided, the pump support 110 includes a fluid inlet 114 configured to allow the fluid pump 100 to draw lubricant from the reservoir 36, and a fluid outlet 116 that is fluidly connected to a first fluid channel 118 in the housing assembly 12. The fluid pump 100 can be any type of pump, such as a gear motor pump, a vane pump, and / or a g-type rotor pump. The fluid pump 100 includes an electric motor 120 that is electrically connected to the control unit 24 (and controlled by it).

[0021] See also Figure 1 , 5 6, the heat exchanger 102 can be mounted to a heat exchanger support 130, which can be incorporated into the housing assembly 12. The heat exchanger 102 can have a first passage configured to receive a flow of a first cooling fluid (such as water) therethrough and a second passage configured to receive a flow of lubricant discharged from the fluid pump 100. In the example shown, the heat exchanger includes an inlet 132 and an outlet 136, the inlet being received in a first port 134 defined by the pump support 110, and the outlet 136 being received in a second port 138 defined by the pump support 110. The first port 134 intersects and is in fluid communication with the first passage 118. The second port 138 is in fluid communication with a second passage 140 in the housing assembly 12.

[0022] The second channel 140 is coupled in fluid communication with the upper reservoir 34. As will be discussed in more detail below, a plurality of lubricant supply channels are coupled in fluid communication with the upper reservoir 34 and distribute lubricant in the upper reservoir 34 to various components of the electric drive unit 10 to cool and / or lubricate the components. It is noteworthy that the flow of lubricant from the upper reservoir 34 to the various lubricant supply channels is based on gravity rather than fluid pressure generated by the fluid pump 100.

[0023] See also Figure 2 and Figures 5 to 8, the upper reservoir 34 has a profile, and the various lubricant supply passages intersect the upper reservoir 34 in a manner such that lubricant supply to certain lubricant supply passages is prioritized over lubricant supply to other lubricant supply passages. For example, the height at which lubricant supply passages 150a, 150b, and 150c intersect the upper reservoir 34 is relatively lower than the height at which lubricant supply passage 150d intersects the upper reservoir 34. In the example provided, lubricant supply passage 150a directs lubricant from the upper reservoir 34 to the motor output shaft bearing 58 and the output shaft bearing 98 located on one end of the housing assembly 12 from which the first output shaft 20 extends, lubricant passage 150b directs lubricant from the upper reservoir 34 to the motor output shaft bearing 58 and the differential bearing 90 located on one end of the housing assembly from which the second output shaft 22 extends, lubricant supply passage 150c directs lubricant from the upper reservoir 34 to the motor output shaft bearing 58 and the differential bearing 90 and the intermediate gear bearing 70 located closest to the input pinion 60, and lubricant supply passage 150d is configured to distribute lubricant to the associated axial ends of the excitation winding 52 of the stator 40. Therefore, because the height at which the lubricant supply passages 150a, 150b, and 150c intersect the upper reservoir 34 is relatively low relative to the height at which the lubricant supply passage 150d intersects the upper reservoir 34, lubrication and cooling of components of the electric drive unit 10 that receive lubricant from the lubricant supply passages 150a, 150b, and 150c are prioritized over lubrication and cooling of components of the electric drive unit 10 that receive lubricant from the lubricant supply passage 150d. Each of the lubricant supply passages 150a, 150b, and 150c can be sized in a desired manner to meter lubricant to be discharged to a desired component at a predetermined rate when the upper reservoir 34 is full of lubricant. The predetermined discharge rate of each of the lubricant supply passages 150a, 150b, and 150c can be determined by the diameter of a portion of the lubricant supply passage or by an appropriately sized orifice that can be mounted to the lubricant supply passage. The lubricant supply passage 150d may be sized to ensure that lubricant can be discharged from the upper reservoir at a desired rate, such as a rate sufficient to prevent pressurization of lubricant in the upper reservoir when the upper reservoir 34 is full and each of the lubricant supply passages 150a, 150b, and 150c discharges lubricant from the upper reservoir 34 at its predetermined rate. The lubricant supply passage 150d may terminate at its upper end, proximate to the cap C of the upper reservoir, to help maintain uniform flow distribution in all of the lubricant supply passages 150a, 150b, 150c, and 150d when a vehicle equipped with the electric drive unit 10 is performing dynamic vehicle maneuvers. Additionally or alternatively, conventional means (such as one or more baffles) may be employed in the upper reservoir 34 to limit sloshing of lubricant in the upper reservoir 34 during dynamic vehicle maneuvers.

[0024] The lubricant discharged from the second passage 140 can be directed in a desired manner within the upper reservoir 34 by various features or structures that can be integrally incorporated into the upper reservoir 34. For example, the upper reservoir 34 can be configured with a contoured bottom surface 170, and features such as a drain groove 172 and / or a plurality of flow dividers 174 can be received in the upper reservoir 34. In the illustrated example, the bottom surface 170 of the upper reservoir 34 formed by the wall member 38 of the housing assembly 12 is formed as a portion of a right circular cylinder that is recessed into a volume defined by a pair of lateral end walls 190a and 190b and a pair of axial end walls 192a and 192b. Thus, the upper reservoir 34 is shallowest along a plane extending through the centerline of the right circular cylinder defining the bottom surface 170, and is deepest at the location where the bottom surface intersects the lateral end walls 190a and 190b. The wall member 38 of the housing assembly 12 may define one or more bosses 200 proximate each of the axial end walls 192a and 192b through which the lubricant supply passage 150d may be formed. The bosses 200 are configured to set or establish the height at which the lubricant supply passage 150d intersects the upper reservoir 34. The drain groove 172 may be integrally incorporated into the lateral end wall 190a and the wall member 38 of the housing assembly 12 and may be disposed around and in line with the second passage 140 to receive lubricant discharged therefrom. The drain groove 172 may direct the lubricant to exit the second passage 140 in a lateral direction (i.e., toward the lateral end wall 190b). The flow divider 174 is configured to intersect portions of the lubricant flow discharged from the drain groove 172 and direct the portions in respective directions toward an associated one of the lateral end wall 190a and the axial end walls 192a and 192b and / or toward the lubricant supply passage 150c. It will be appreciated that the flow diverters 174 are spaced apart from one another or configured such that a portion of the lubricant flow discharged from the drain groove 172 will pass through the flow diverters 174 to reach an area laterally located between the flow diverters 174 and the lateral end wall 190b. Depending on the velocity of the lubricant passing through the flow diverters 174, the lubricant may strike or impact the lateral end wall 190b and return to the flow diverters 174. If desired, the flow diverters 174 may be configured to direct the returning lubricant in a desired manner, such as laterally toward the lateral end wall 190b and axially toward a respective one of the axial end walls 192a and 192b and / or toward a respective one of the lubricant supply passages 150a and 150b.

[0025] It will be appreciated that the bottom surface 170 of the upper reservoir 34 may be further contoured to promote lubricant flow and drainage to a desired area. For example, the bottom surface 170 of the upper reservoir 34 may be partially or fully contoured (e.g., tapered) so that lubricant in the upper reservoir 34 is discharged toward the axial end walls 192a and 192b.

[0026] Back to Figure 2 and Figure 6, the electric motor 14 is positioned in the first cavity 30 of the housing assembly 12 at a position in which, when the electric drive unit 10 is operated in a nominal orientation (i.e., the orientation of the electric drive unit 10 when the electric drive unit 10 is integrally incorporated into a vehicle and the vehicle is traveling on flat, level ground), a portion of the field windings 52 of the stator 40 is disposed at or below a lubricant level 250 established by the lubricant in the reservoir 36. The lubricant level 250 in the reservoir 36 does not intersect the rotor 42, such that the lubricant in the reservoir 36 does not create drag on the rotor 42 when the electric drive unit 10 is operated in a predetermined rolling range about a longitudinal vehicle axis that is perpendicular to the rotational axis 56. It will be appreciated that submerging a portion of the field windings 52 of the stator 40 in the lubricant in the reservoir 36 provides enhanced cooling of the electric motor 14.

[0027] exist Fig. 9 and Fig.10 , the electric drive unit 10 is schematically shown as being integrally integrated into a vehicle environment. The vehicle 300 may provide a supply of a suitable coolant, such as a water-glycol mixture, which may be passed through the inverter 302 of the control unit 24 and through the heat exchanger 102 to remove heat from the inverter 302 and the heat exchanger 102. The fluid pump 100 draws lubricant (which may be a type of automatic transmission fluid) from the reservoir 36 and circulates the lubricant through the heat exchanger 102. The cooled lubricant flowing from the heat exchanger 102 is discharged into the upper reservoir 34.

[0028] exist Fig.10 and Fig.11 In the embodiment, the cooled lubricant in the upper reservoir 34 is discharged from the lubricant supply passages 150a, 150b and 150c ( Figure 7 ) is discharged to lubricate the differential support bearing 90, the motor output shaft bearing 58, the output shaft bearing 98, the matching teeth of the input pinion 60 and the first intermediate gear 62, the second intermediate gear 64 ( Figure 3 ) and the matching teeth of the output gear 66, as well as the differential assembly 18, while the lubricant from the lubricant supply passage 150d can be used to cool the field winding 52 of the stator 40. In addition, the lubricant supply passage 150a ( Figure 7) A portion of the lubricant discharged from the upper reservoir 34 may be directed to an annular reservoir 310 formed in the housing assembly 12 around the first output shaft 20. The lubricant in the annular reservoir 310 may be discharged into an annular space 312 radially disposed between the first output shaft 20 and the motor output shaft 44. The lubricant in the annular space 312 may be discharged through one or more supply apertures 314 formed radially through the motor output shaft 44 and may enter one or more fluid passages 320 formed in the rotor 42. The fluid passages 320 in the rotor may be formed in any desired manner, but in the example provided, a plurality of axial passage segments formed axially through a portion of the rotor 42 and a plurality of radial passage segments each interconnected with a pair of axial passage segments are formed. The (one or more) fluid passages 320 in the rotor 42 may terminate at the outer peripheral surface of the rotor 42 and may be located at a desired location so that the lubricant discharged from the (one or more) fluid passages 320 may be flung from the rotor 42 to a desired target, such as the axial end of the field winding 52 of the stator 40. During operation of electric drive unit 10 , centrifugal forces acting on the lubricant in rotor 42 may help draw lubricant from annular space 312 into and through fluid passage(s) 320 .

[0029] See also Figure 1 , 2 7, thus far, a cooling and lubrication system 26 has been shown and described as having a plurality of lubricant supply passages that provide a flow of lubricant to various components of the electric drive unit 10 under gravity feed to lubricate and / or cool these components. However, it will be appreciated that the electric drive unit 10 may be configured slightly differently. For example, the cooling and lubrication system 26 may be configured to provide pressurized fluid to various ones of the lubricant supply passages to lubricate and / or cool certain components of the electric drive unit 10 with the pressurized lubricant, and to supply lubricant to the remaining lubricant supply passages using the upper reservoir 34 so that a gravity feed of lubricant may be achieved via these remaining lubricant supply passages. For example, one or more of the lubricant supply passages 150a, 150b, and 150c may be fluidly coupled to the second passage 140 to receive pressurized lubricant therefrom, and a suitable device (not shown) (such as a flow restrictor or a pressure relief valve) may be positioned in the second passage 140 to provide lubricant to the upper reservoir 34 while limiting pressure loss to the lubricant supply passage / passages receiving pressurized lubricant from the second passage 140. Additionally or alternatively, one or more flow restrictors (not shown) may be used in any of the lubricant supply passages that receive pressurized lubricant and / or in any of the passages that provide pressurized lubricant to one or more of the lubricant supply passages that receive pressurized lubricant.

[0030] exist Fig.12In the example of the embodiment of the present invention, the cooling and lubrication system 26a is configured to provide pressurized lubricant to the rotor 42a during operation of the electric drive unit 10a, and to supply lubricant to the upper reservoir 34a. One or more flow restriction devices may be used in the cooling and lubrication system 26a to control the flow of lubricant to the rotor 42a and / or the upper reservoir 34a. In the specific example provided, the cooling and lubrication system 26a provides a pressurized lubricant flow to a radially inward position of the rotor 42a, such as between the motor output shaft 44a and the first output shaft (not specifically shown), and then the lubricant is directed through the rotor 42a in a radially outward direction due to the fluid pressure of the lubricant and / or by centrifugal force. The lubricant may leave the rotor 42a from the radially outward surface of the rotor 42a and may be directed to the radially inward surface of the stator 40 to provide additional cooling to the stator 40.

[0031] The description of the foregoing embodiments is provided for illustration and description purposes only. It is not intended to be exhaustive or to limit the present disclosure. The individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but are interchangeable where applicable and can be used in selected embodiments, even if not specifically shown or described. It can also be varied in many ways. These variations 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. An electric drive unit, comprising: a housing assembly defining a first cavity, a second cavity, a reservoir, and an upper reservoir, the reservoir being coupled in fluid communication with the first cavity, the upper reservoir being spaced apart from the reservoir and the first cavity; an electric motor received in the first cavity, the electric motor having a stator, a rotor and a motor output shaft, the stator having a stator core fixedly coupled to the housing assembly and a plurality of windings, the rotor received within the stator and rotatable about a rotation axis, the motor output shaft coupled to the rotor to rotate with the rotor about the rotation axis; a differential assembly in the second cavity, the differential assembly having a differential input member rotatable relative to the housing assembly, and a first differential output member and a second differential output member rotatable relative to the differential input member; a first output shaft coupled to the first differential output member for rotation therewith; a second output shaft coupled to the second differential output member for rotation therewith; a transmission received in the second cavity, the transmission configured to transmit rotational power between the motor output shaft and the differential input member; as well as a fluid pump configured to draw lubricant from the reservoir and provide a flow of lubricant; wherein at least a portion of said lubricant flow is discharged into said upper reservoir; wherein the housing assembly defines a plurality of first lubricant supply passages and a plurality of second lubricant supply passages, each of the first lubricant supply passages and the second lubricant supply passages being a conduit that allows lubricant in the upper reservoir to drain due to gravity to associated components of the electric drive unit to lubricate and / or cool the associated components; wherein the first lubricant supply passage intersects the upper reservoir at an associated position less than or equal to a first height dimension, wherein the second lubricant supply passage intersects the upper reservoir at a corresponding position greater than or equal to a second height dimension, the second height dimension being relatively greater than the first height dimension. 2 . The electric drive unit of claim 1 , wherein at least a portion of the second lubricant supply passage is configured to direct lubricant onto a portion of the stator.

3. The electric drive unit of claim 2, wherein a portion of the stator comprises a winding.

4. The electric drive unit of claim 1, wherein each of at least a portion of the first lubricant supply passages provides lubricant to an associated bearing. 5 . The electric drive unit of claim 4 , further comprising first and second motor output shaft bearings mounted to the housing assembly and supporting the motor output shaft for rotation relative to the housing assembly. 6 . The electric drive unit of claim 4 , further comprising first and second differential bearings mounted to the housing assembly and supporting the differential input member for rotation relative to the housing assembly. 7 .

7. The electric drive unit according to claim 4 further includes a first output shaft bearing and a second output shaft bearing, wherein the first output shaft bearing is mounted to the housing assembly and supports the first output shaft for rotation relative to the housing assembly, and the second output shaft bearing is mounted to the housing assembly and supports the second output shaft for rotation relative to the housing assembly.

8. The electric drive unit according to claim 4, wherein the transmission includes an input pinion connected to the motor output shaft to rotate with the motor output shaft, an output gear rotatably connected to the differential input component, a first intermediate gear meshingly engaged with the input pinion, a second intermediate gear rotatably connected to the first intermediate gear and meshingly engaged with the output gear, and a pair of intermediate gear bearings mounted to the housing assembly and supporting the first intermediate gear and the second intermediate gear for rotation relative to the housing assembly.

9. The electric drive unit of claim 1, wherein the first output shaft and the second output shaft are rotatable about the rotation axis.

10. The electric drive unit of claim 1, wherein the differential input member is a differential case.

11. The electric drive unit of claim 10, wherein the differential output member is a side gear.

12. The electric drive unit of claim 11, wherein the differential assembly includes a plurality of differential pinions, each of the differential pinions meshingly engaging with two of the side gears.

13. The electric drive unit of claim 1, wherein a portion of the lubricant flow is directed into the rotor.

14. The electric drive unit according to claim 1 further includes at least one diverter disposed in the upper reservoir, each of the at least one diverter being disposed at a position intersecting with a portion of the lubricant flow discharged into the upper reservoir and directing the intersecting portion of the lubricant flow to a desired area within the upper reservoir.

15. The electric drive unit of claim 14, wherein the desired area within the upper reservoir includes an area proximate at least one of the first lubricant supply passages.

16. The electric drive unit of claim 15, further comprising a drain trough received in the reservoir, the drain trough directing a flow of lubricant draining into the upper reservoir generally toward the at least one flow diverter.

17. The electric drive unit of claim 16, wherein the at least one flow divider comprises two flow dividers spaced apart from each other, and wherein the drain groove directs the lubricant flow discharged into the upper reservoir toward each of the two flow dividers and into the space between the two flow dividers.

18. The electric drive unit of claim 1 , further comprising a cover coupled to the housing and enclosing the upper reservoir, wherein the cover is disposed at a third height dimension greater than the second height dimension, and wherein the second lubricant supply passage intersects the upper reservoir in relatively close proximity to the cover to ensure uniform flow distribution from the upper reservoir to the first lubricant supply passage and the second lubricant supply passage during dynamic vehicle maneuvers.

19. The electric drive unit of claim 1, wherein each of the first lubricant supply passages is configured to pass lubricant therethrough at a predetermined rate.

20. An electric drive unit, comprising: a housing assembly defining a first cavity, a second cavity, and a reservoir; an electric motor received in the first cavity, the electric motor having a stator, a rotor and a motor output shaft, the stator having a stator core fixedly coupled to the housing assembly and a plurality of windings, the rotor received within the stator and rotatable about a rotation axis, the motor output shaft coupled to the rotor to rotate with the rotor about the rotation axis; a differential assembly in the second cavity, the differential assembly having a differential input member rotatable relative to the housing assembly, and a first differential output member and a second differential output member rotatable relative to the differential input member; a first output shaft coupled to the first differential output member for rotation therewith; a second output shaft coupled to the second differential output member for rotation therewith; a transmission received in the second cavity, the transmission configured to transmit rotational power between the motor output shaft and the differential input member; as well as a lubricant in the reservoir, the lubricant configured to cool and / or lubricate components of the electric drive unit, the lubricant establishing a predetermined lubricant level in the reservoir when the electric drive unit is operated in a nominal orientation; wherein the reservoir intersects the first cavity such that a portion of the stator is disposed in lubricant in the reservoir, and wherein a predetermined lubricant level in the reservoir is spaced apart from the rotor such that the rotor does not spin through the lubricant in the reservoir when the electric drive unit is operated in a nominal orientation.

21. The electric drive unit of claim 20, wherein the first output shaft and the second output shaft are rotatable about the rotational axis.

22. The electric drive unit of claim 20, wherein the differential input member is a differential case.

23. The electric drive unit of claim 22, wherein the differential output member is a side gear.

24. The electric drive unit of claim 23, wherein the differential assembly includes a plurality of differential pinions, each of the differential pinions meshingly engaging with two of the side gears.

25. The electric drive unit of claim 20, further comprising a cooling and lubrication system having a fluid pump and a heat exchanger, the fluid pump configured to draw lubricant from the reservoir and supply the lubricant flow to the heat exchanger.

26. The electric drive unit of claim 25, wherein a portion of the lubricant flow exiting the heat exchanger is directed into the rotor.

27. The electric drive unit of claim 25, wherein a portion of the lubricant flow exiting the heat exchanger is directed into windings of the stator to cool the stator.

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