Electric axle assembly

Abstract

The electric axle assembly comprises a driving unit and a transmission system stored in a shell. And a cooling system coupled to the housing for circulating a cooling fluid through the housing. An electric axle assembly is mounted to a vehicle to support the vehicle for movement along a ground surface. The drive unit provides motive power to wheels of the vehicle through the driveline to propel the vehicle along the ground.

Description

[0001] This application is a divisional application of the Chinese invention patent application CN201980074834.8 (International Application No. PCT / US2019 / 053648) filed on September 27, 2019, with the invention name “Electric Wheel Axle Assembly”.

[0002] Cross-reference to related U.S. patent applications

[0003] This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Serial No. 62 / 737,452, filed on September 27, 2018, the entire contents of which are incorporated herein by reference. Technical Field

[0004] The present disclosure relates generally to axle assemblies for vehicles, and more particularly, to electric axle assemblies for vehicles. Background Art

[0005] Many vehicles utilize wheel axles to support the vehicle. At least some of these axles are drive axles capable of propelling the vehicle. Typically, an internal combustion engine is coupled to the drive axle via a drive shaft. Manufacturers are increasingly turning to electric and hybrid propulsion systems to improve performance and efficiency.

[0006] Therefore, there is a need to provide an axle assembly that allows one or more electric drive units to be packaged into a vehicle while optimizing efficiency and performance. Summary of the invention

[0007] According to one aspect of the present disclosure, an electric wheel axle assembly includes a drive assembly and a cooling system coupled to the drive assembly. The drive assembly may include a drive unit and a transmission system housed in a housing. The drive unit may be engaged with the transmission system and configured to provide motive force to the transmission system. The cooling system may include a pump, a heat exchanger, and a fluid transport network. The pump may be configured to transfer a cooling fluid from the housing to the heat exchanger. The heat exchanger may be configured to absorb heat from the cooling fluid. The fluid transport network may be configured to transfer the cooling fluid from the heat exchanger to at least one of the drive unit and the transmission system.

[0008] In illustrative embodiments, the fluid delivery network may include at least one of a conduit coupled to the housing and a channel formed into the housing.

[0009] In illustrative embodiments, a conduit may be in fluid communication with the channel.

[0010] In illustrative embodiments, the fluid delivery network may be configured to direct cooling fluid onto and / or into the drive unit for cooling the drive unit.

[0011] In an illustrative embodiment, the drive assembly may be a first drive assembly, and the electric axle assembly may further include a suspension frame and a second drive assembly.The first drive assembly and the second drive assembly may be coupled to opposite sides of the suspension frame.

[0012] In an illustrative embodiment, a cooling system may be coupled to the first and second drive assemblies.

[0013] In an illustrative embodiment, the cooling system may be a first cooling system coupled to the first drive assembly, and the electric axle assembly may further include a second cooling system coupled to the second drive assembly.

[0014] In an illustrative embodiment, an exchange medium may flow through the heat exchanger and transfer heat from the cooling fluid to the exchange medium in the heat exchanger.

[0015] In an illustrative embodiment, the housing may be formed to define a sump for collecting the cooling fluid. The pump may draw the cooling fluid from the sump. The cooling fluid may be configured to extract heat from the drive unit and flow into the sump.

[0016] In an illustrative embodiment, the cooling fluid may be configured to lubricate at least one of the drive unit and the drive train.

[0017] According to one aspect of the present disclosure, a cooling system can be used with a drive unit having a stator and a rotor, the rotor having a core and a winding coupled to the core, and the rotor being adapted to rotate relative to the stator. The cooling system may include a pump, a heat exchanger, and a fluid delivery network. The pump may be configured to transfer a cooling fluid to the heat exchanger. The heat exchanger may be configured to extract heat from the cooling fluid. The fluid delivery network may be configured to transfer the cooling fluid from the heat exchanger to the drive unit.

[0018] In illustrative embodiments, the fluid delivery network may be configured to direct cooling fluid onto and / or into the drive unit for cooling the drive unit.

[0019] In an illustrative embodiment, an exchange medium may flow through the heat exchanger and transfer heat from the cooling fluid to the exchange medium in the heat exchanger.

[0020] In an illustrative embodiment, the cooling fluid may be configured to lubricate the drive unit.

[0021] In illustrative embodiments, the fluid delivery network may include at least one of a conduit coupled to a housing housing the drive unit and a channel formed into the housing.

[0022] In an illustrative embodiment, the fluid delivery network may include a plurality of conduits including at least one of: a winding sprayer configured to spray a cooling fluid onto windings of the stator; a core sprayer configured to spray a cooling fluid onto a core of the stator; and a feed tube configured to deliver the cooling fluid to a ring coupled to a drive unit.

[0023] According to one aspect of the present disclosure, a drive assembly includes a housing, a transmission system contained in the housing, a drive unit contained in the housing, and a cooling system coupled to the housing. The drive unit may be engaged with the transmission system and configured to provide motive force to the transmission system during operation of the drive unit. The cooling system may include a pump, a heat exchanger, and a fluid transport network. The pump may be configured to transfer a cooling fluid from the housing to the heat exchanger. The heat exchanger may be configured to absorb heat from the cooling fluid. The fluid transport network may be configured to guide the cooling fluid to the drive unit and / or into the drive unit for cooling the drive unit. The fluid transport network may also be configured to transfer the cooling fluid from the heat exchanger to at least one of the drive unit and the transmission system.

[0024] In illustrative embodiments, the fluid delivery network may include at least one of a conduit coupled to the housing and a channel formed into the housing, and the conduit may be in fluid communication with the channel.

[0025] In an illustrative embodiment, an exchange medium may flow through the heat exchanger and transfer heat from the cooling fluid to the exchange medium in the heat exchanger.

[0026] In an illustrative embodiment, the housing may be formed to define a sump for collecting the cooling fluid. The pump may draw the cooling fluid from the sump. The cooling fluid may be configured to extract heat from the drive unit and flow into the sump.

[0027] In an illustrative embodiment, the cooling fluid may be configured to lubricate at least one of the drive unit and the drive train. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In the accompanying drawings (referred to herein simply as "figures" or "diagrams"), the systems and methods described herein are illustrated by way of example and not limitation. For simplicity and clarity of illustration, the elements illustrated in the drawings are not necessarily drawn to scale. For example, the dimensions of some elements may be exaggerated relative to other elements for clarity. In addition, where considered appropriate, reference numerals have been repeated between the drawings to indicate corresponding or similar elements.

[0029] Figure 1 is a front view of an electric axle assembly for a low-floor vehicle according to a first embodiment of the present disclosure.

[0030] Figure 2yes Figure 1 A front perspective view of the motorized axle assembly is shown.

[0031] Figure 3 yes Figure 1 A rear perspective view of an electric axle assembly of FIG. 1 is shown schematically illustrating an exemplary cooling system for the electric axle assembly.

[0032] Figure 4 yes Figure 3 A top plan view of an electric wheel axle assembly.

[0033] Figure 5 yes Figure 3 A partial rear perspective view of the electric wheel axle assembly with the suspension and wheel end assembly removed.

[0034] Figure 6 yes Figure 5 Rear view of the electric wheel axle assembly.

[0035] Fig. 7A It is along Figure 3 A cross-sectional perspective view taken along line 7A-7A in FIG.

[0036] Figure 7B is with Fig. 7A Similar views.

[0037] Figure 8 is with Fig. 7A Similar views.

[0038] Fig. 9 yes Figure 5 A rear perspective view of the electric wheel axle assembly with a portion of the housing removed.

[0039] Fig.10 is with Fig. 9 A similar view with the housing removed and the cooling system schematically shown.

[0040] Fig.11 is used for Figure 1 A perspective view of an exemplary gear train and drive unit of a wheel axle assembly is shown.

[0041] Fig.12 yes Fig.11 A perspective view of the drive unit as well as part of the gear train and cooling system.

[0042] Fig.13 is similar to Fig.12 of the view.

[0043] Fig.14 is a front perspective view of an electric axle assembly according to a second embodiment of the present disclosure.

[0044] Fig.15 yes Fig.14 A rear perspective view of the electric wheel axle assembly.

[0045] Fig.16 is along Fig.14 A cross-sectional view taken along line 16-16 in FIG.

[0046] Fig.17 is along Fig.14 A cross-sectional view taken along line 17-17 in FIG.

[0047] Fig.18 yes Fig.17 A perspective cross-sectional view of an electric wheel axle assembly.

[0048] Fig.19 yes Fig.16 A partial perspective cross-sectional view of an electric wheel axle assembly.

[0049] Fig. 20 yes Fig.14 A partial front perspective view of an electric wheel axle assembly with the housing removed to expose the drive unit, gear train and cooling system of the electric wheel axle assembly.

[0050] Fig.21 yes Fig. 20 Another perspective view of the electric wheel axle assembly.

[0051] Fig. 22 yes Fig. 20 A partial perspective cross-sectional view of an electric wheel axle assembly.

[0052] Fig.23 is used for Fig.14 A perspective view of a housing of an electric wheel axle assembly including a channel formed in the housing.

[0053] Fig.24 is used for Fig.14 A perspective view of the pump of the electric axle assembly.

[0054] Fig.25 yes Fig.21 A perspective view of a portion of the drive unit and gear train of an electric axle assembly including a cooling system.

[0055] Fig.26 yes Fig.25 Another perspective view of a portion of the drive unit and cooling system of the electric axle assembly.

[0056] Fig. 27 yes Fig.21 Another perspective view of the drive unit and cooling system.

[0057] Fig.28 is similar to Fig. 27 of the view.

[0058] Fig.29 yes Fig.14 A perspective view of a motorized wheel axle assembly with a portion of the housing removed showing the oil catchment portion and windage disc.

[0059] Fig.30 is along Fig.29 A perspective cross-sectional view taken along line 30 - 30 in FIG. 1 shows the oil collecting portion and the windage disc.

[0060] Figure 31-42 An electric axle assembly according to a third embodiment of the present disclosure is shown.

[0061] Figure 43-50 An electric axle assembly according to a fourth embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0062] Although the concepts of the present disclosure are susceptible to various modifications and alternative forms, specific exemplary embodiments thereof have been shown by way of example in the accompanying drawings and will be described in detail herein. However, it should be understood that there is no intention to limit the concepts of the present disclosure to the particular forms disclosed, but on the contrary, it is intended to cover all modifications, equivalent forms and alternative forms that fall within the spirit and scope of the disclosure as defined by the appended claims.

[0063] References in the specification to "one embodiment," "an embodiment," "an example embodiment," etc. indicate that the described embodiment may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. In addition, when a particular feature, structure, or characteristic is described in conjunction with an embodiment, whether or not explicitly described, it is considered to be within the knowledge of those skilled in the art to implement such feature, structure, or characteristic in conjunction with other embodiments.

[0064] The illustrative electric wheel axle assembly 100 according to the present disclosure is Figure 1-4 . The electric wheel axle assembly 100 can be used, for example, in a low-floor vehicle (e.g., a bus) to support the vehicle for traveling on the ground and to propel the vehicle. The electric wheel axle assembly 100 includes a suspension frame 102 and a pair of drive assemblies 104 coupled to opposite sides of the suspension frame 102. The suspension frame 102 is attached to a vehicle frame (not shown) to support the drive assemblies 104 relative to the vehicle frame. A controller 105 controls the operation of the electric wheel axle assembly 100. Each of the drive assemblies 104 includes a drive unit 106, such as an electric motor, and a drive train 108. As shown in FIG. Fig. 9 As shown, the drive unit 106 and the drive train 108 are accommodated in the housing 103 of the drive assembly 104. Figure 1As shown, the wheel hub 109 allows the wheel 101 to be attached to the drive assembly 104 to rotate about the wheel axis A as the drive train 108 rotates. The drive unit 106 provides motive force to the wheel 101 through the transmission system 108 to propel the vehicle along the ground. Fig.11 An exemplary drive unit 106 and transmission 108 are shown in FIG. Examples of axle assemblies for low-floor vehicles are shown in International Patent Application Publication No. WO2019 / 014479 and International Patent Application No. PCT / US2019 / 031786, the entire contents of both applications are incorporated herein by reference in their entirety.

[0065] like Figure 3-10 As shown, a cooling system 10 according to the present disclosure circulates a cooling fluid (e.g., oil, transmission fluid, or other substantially non-conductive fluid) to a drive assembly 104. During operation, the cooling fluid circulated by the cooling system 10 controls the heat generated by the drive unit 106. In the illustrative embodiment, as shown Figure 3-6 As shown, the cooling system 10 includes a pump 12 and a heat exchanger 14. The pump 12 extracts cooling fluid from the housing 103 of the drive assembly 104 through a conduit 16. The pump 12 can be driven by one of the drive unit 106 and / or the transmission 108 and / or by a separate drive device. The cooling fluid passes through the heat exchanger 14 to remove heat from the cooling fluid. The cooling fluid passes through the conduit (schematically represented by the arrow 19 showing the flow direction) and enters the housing 103 through the inlet 18. The cooling fluid is distributed through the housing 103 to cool and / or lubricate the drive unit 106 and / or the driver 108. In some embodiments, the heat exchanger 14 is an air-cooled heat exchanger. In some embodiments, the heat exchanger 14 is a liquid-cooled heat exchanger that circulates an exchange medium (e.g., water or antifreeze) in a parallel flow or counter-flow manner to draw heat from the cooling fluid into the exchange medium. In some embodiments, the exchange medium can be used in another cooling system at other locations of the vehicle to cool other vehicle components, such as batteries and / or power inverters. In some embodiments, multiple pumps 12 and / or heat exchangers 14 may be used. In some embodiments, each drive assembly 104 is provided with its own cooling system 10 .

[0066] The cooling fluid flows onto and / or into the drive unit 106 and / or the transmission 108 and down to a lower portion of the housing 103 (e.g., near the suspension frame 102), which defines a sump 107 for collecting the cooling fluid. Fig. 9 , 10, 12 and 13 (with the cover removed), the aspirator 15 is disposed in the sump 107 and fluidly coupled to the pump 12 (e.g., via the conduit 16) to extract cooling fluid from the housing 103 for recirculation. In some embodiments, the aspirator 15 includes a filter to remove debris from the cooling fluid. In some embodiments, the filter is coupled to the cooling system 10 outside the housing 103 to remove debris from the cooling fluid. One or more gears of the transmission 108 may extend into the sump 107 to spread the cooling fluid to other gears of the transmission 108. The rotation of the gears may also splash the cooling fluid throughout the housing 103 to lubricate the contact surfaces.

[0067] exist Figure 11-13 An exemplary drive unit 106 is shown in FIG. The drive unit 106 includes a stator 92 and a rotor 94. The stator 92 is coupled to a housing 103 of the drive assembly 104, and the rotor 94 is configured to rotate relative to the stator 92 about an axis B. Fig.12 As shown, pinion 96 is coupled to rotor 94 and engages with drive train 108 to transfer motive force from drive unit 106 to drive train 108. In some embodiments, drive unit 106 includes internal passages in stator 92 and / or rotor 94 for flowing cooling fluid through drive unit 106. Stator 92 includes core 95 and windings 97, as shown in FIG. Figure 7A-8 The core 95 has a tubular profile and the winding 97 includes an electrical conductor (eg, copper wire) distributed circumferentially around the core 95 , the electrical conductor receiving electrical energy to generate a magnetic field for driving the rotor 94 to rotate.

[0068] In the illustrated embodiment, one or more conduits 11 are provided as part of the cooling system 10 for directing cooling fluid from the heat exchanger 14 to the drive unit 106 and / or the drive train 108. The conduits 11 can be configured to pass the cooling fluid into the internal passages of the drive unit 106 and / or direct the cooling fluid onto the drive unit 106. In some embodiments, as shown in FIG. Figure 7A-8As shown, the conduit 11 is coupled to a channel 13 in the housing 103 to pass the cooling fluid from the inlet 18 to the drive unit 106 and / or the transmission 108. The channel 13 extends along and through a portion of the housing 103 to distribute the cooling fluid to the conduit 11 and otherwise circulate the cooling fluid around the drive assembly 104. The channel 13 can be formed as part of the casting process or post-processing of the housing 103, for example. In some embodiments, the channel 13 of the housing 103 is used without the conduit 11. In some embodiments, the conduit 11 is used without the channel 13. In some embodiments, one or more rings 17 are configured to receive the cooling fluid and distribute the cooling fluid around the stator 92 and / or the rotor 94, for example, for distributing the cooling fluid to the channel in the drive unit 106. In some embodiments, the cover 98 coupled to the housing 103 is configured to receive the cooling fluid from the channel 13 of the housing 103 and pass the cooling fluid to the rotor 94 and / or the stator 92 of the drive unit 106.

[0069] In an exemplary embodiment, if Figure 7A-10 As shown in Figures 12-13, the conduit 11 may include one or more core sprayers 21, a feed tube 22, a transfer tube 23, a winding sprayer 24, and other possible conduit configurations for conveying cooling fluid through the drive assembly 104. The cooling fluid may be supplied to the conduit 11 through one or more of the channels 13 in the housing 103 or may be supplied to the conduit 11 from the pump 12 in other ways. In the illustrative embodiment, the core sprayer 21 is disposed above the drive unit 106 and is in fluid communication with the channels 13 of the housing 103. The core sprayer 21 may be formed to define a plurality of legs ( Fig.12 ) having a generally S-shaped or U-shaped profile, wherein one or more of the legs are formed to include one or more outlet holes 25 ( Fig. 7A ). The cooling fluid flowing into the core sprayer 21 is distributed into each leg, which feeds a series of outlet holes 25 to spray the cooling fluid onto the core 95 of the stator 92. It is contemplated that the core sprayer 21 may define more or less than three legs. Other configurations are also contemplated. Fig. 7A and 7B As shown, the feed tube 22 conveys the cooling fluid from the channel 13 of the housing 103 to the ring 17 having one or more internal channels 29 for distributing the cooling fluid around the drive unit 106 and for use by the drive unit 106. In some embodiments, the channel 29 of the ring 17 can be formed as a cavity, for example, during the molding process using an insert molding process or by a machining operation. The transmission tube 23 guides the cooling fluid to the transmission system 108 and other parts of the transmission assembly 104.

[0070] The winding sprayer 24 may be disposed above the winding 97 of the drive unit 106 and formed to include an outlet hole 26 to spray the cooling fluid onto the winding 97, such as Fig. 7A As shown. In some embodiments, the winding sprayer 24 is coupled to the ring 17 and receives the cooling fluid from the feed tube 22 through the ring 17. In some embodiments, the winding sprayers 24 are located on both sides of the drive unit 106. The winding sprayers 24 can be formed with a contoured portion that provides a gap between the winding sprayers 24 and the winding 97. Other configurations can be conceived. In some embodiments, one or more of the channels 13 in the housing 103 define a rear sprayer 27 for spraying cooling fluid onto the winding 97 opposite to the winding sprayer 24. In some embodiments, the rear sprayer 27 is formed in the housing 103 in an arc path around the drive unit 106. In some embodiments, the rear sprayer 27 includes a series of outlet holes 28 that are circumferentially distributed around the drive unit 106 above the winding 97 for spraying cooling fluid onto the winding 97. Other configurations can be conceived.

[0071] In the illustrated embodiment, the ring 17 further serves as a clamping ring for holding the drive unit 106 to the housing 103, as shown in FIG. Figure 8 As shown. For example, fasteners such as studs 91 and nuts 93 engage with the clamping ring 17 and the housing 103 to hold the drive unit 106 on the housing 103. The studs 91 are distributed circumferentially around the drive unit 106 and extend through the clamping ring 17 to engage with the housing 103, for example, by mating threads on the studs 91 and the nuts 93. The nuts 93 engage with the studs 91, for example, by mating threads on the studs 91 and the nuts 93 and engage with the clamping ring 17 to press the clamping ring 17 against the stator 92 and the stator 92 against the housing 103. The clamping ring 17 evenly distributes the clamping force from the fasteners around the stator 92. In some embodiments, the studs 91 extend through the stator 92. The clamping ring 17 can be formed as a single component or multiple parts assembled together. In some embodiments, the clamping ring 17 includes one or more compression limiters to prevent the clamping ring 17 from deforming when the fasteners are tightened. The compression limiter may be formed of a metal such as steel or aluminum that can withstand the compression force from the fastener. For example, the compression limiter may be fixed to the clamping ring 17 by pressing or insert molding.

[0072] The conduits 11 , channels 13 , and other structures described herein and contemplated by the present disclosure for moving cooling fluid through the drive assembly 104 may be collectively referred to as a fluid delivery network 60 of the cooling system 10 .

[0073] According to another embodiment of the electric wheel axle assembly 200 of the present disclosure, Figure 14-18. The electric axle assembly 200 can be used, for example, in a single-axle or multi-axle pulling or hauling vehicle (e.g., a semi-truck) to support the vehicle for traveling on the ground and propelling the vehicle. The electric axle assembly 200 includes a drive assembly 204 and an axle tube 202 extending from opposite sides of the drive assembly 204. The electric axle assembly 200 is attached to a suspension device (not shown) of the vehicle, which is used to support the drive assembly 204 relative to the vehicle frame. The controller 205 controls the operation of the electric axle assembly 200. The drive assembly 204 includes a drive input 230 and a transmission 208. In the illustrative embodiment, the drive input 230 includes a pair of drive units 206, such as electric motors. The drive unit 206 and the transmission 208 are housed in a housing 203 of the drive assembly 204. The transmission 208 extends through the axle tube 202 to engage with the wheel hub 209. As shown Fig.15 As shown, wheel hub 209 allows the wheels to be attached to drive assembly 204 for rotation about axis A by rotation of drive train 208 through drive input 230. Drive unit 206 provides motive force to the wheels through drive train 208 to propel the vehicle along the ground. Fig. 20 and Fig.21 An exemplary drive input 230 and drive train 208 are shown in . Other examples of wheel axle assemblies are shown in PCT International Patent Application Publication Nos. WO2019 / 161390 and WO2019 / 161395, the disclosures of which are incorporated herein by reference in their entirety.

[0074] The cooling system 210 according to the present disclosure circulates a cooling fluid, such as oil, transmission fluid, or other substantially non-conductive fluid, to the drive assembly 204. Fig.14 , 20 21. During operation, the cooling fluid circulated by the cooling system 210 controls the heat generated by the drive unit 206. In the illustrated embodiment, the cooling system 210 includes a pump 212 and a heat exchanger 214. Fig.24 As shown, pump 212 draws cooling fluid from housing 203 through one or more conduits 216. In some embodiments, two conduits 216 feed cooling fluid from housing 203 to pump 212, and two conduits 232 feed cooling fluid from pump 212 to a merging block to provide a single flow to heat exchanger 214. Pump 212 may be driven by one of drive unit 206 / drive train 208 and / or by a separate transmission. The cooling fluid passes through heat exchanger 214 to remove heat from the cooling fluid. Fig.14As shown, the cooling fluid passes through one or more conduits 219 and enters the housing 203 through one or more inlets 218. The cooling fluid is distributed through the housing 203 for cooling and / or lubricating the drive unit 206 and / or the transmission 208. In some embodiments, the heat exchanger 214 is an air-cooled heat exchanger. In some embodiments, the heat exchanger 214 is a liquid-cooled heat exchanger that transfers an exchange medium (e.g., water or antifreeze) in a parallel flow or counter-flow manner to draw heat from the cooling fluid to the exchange medium. In some embodiments, the exchange medium can be used in another cooling system at other locations of the vehicle to cool other vehicle components, such as batteries and / or power inverters. In some embodiments, multiple pumps 212 and / or heat exchangers 214 can be used. In some embodiments, each drive unit 206 is provided with its own cooling system 210.

[0075] The cooling fluid flows onto and / or into the drive unit 206 and / or the transmission 208 and flows downward to a lower portion of the housing 203 (e.g., below the axle tube 202), which defines a sump 207 for collecting the cooling fluid. In some embodiments, an aspirator 215 is disposed in the sump 207 and is fluidly coupled to a pump 212 (e.g., via a conduit 216) to extract the cooling fluid from the housing 203 for recirculation, such as Fig.16 , 19 25. In some embodiments, the aspirator 215 includes a filter to remove debris from the cooling fluid. In some embodiments, the filter is coupled to the cooling system 210 outside the housing 203 to remove debris from the cooling fluid. One or more gears in the transmission 208 can extend into the sump 207 to distribute the cooling fluid to other gears in the transmission 208, such as Fig.29 and 30 The rotation of the gears can also splash cooling fluid throughout the housing 203 for lubricating the contact surfaces.

[0076] exist Figure 20-22An exemplary drive unit 206 is shown in FIGS. 206 and 25. The drive unit 206 may be configured similarly to the drive unit 106 described above. In an illustrative embodiment, the drive units 206 each include a stator 292 and a rotor 294. The stator 292 is coupled to the housing 203 of the drive assembly 204, and the rotor 294 is configured to rotate relative to the stator 292 about respective axes B, C. A pinion 296 is coupled to the rotor 294 and engages with the transmission 208 to transfer motive force from the transmission unit 206 to the transmission 208. In some embodiments, the transmission unit 206 includes an internal passage located in the stator 292 and / or the rotor 294 for flowing a cooling fluid through the drive unit 206. The stator 292 includes a core 295 and a winding 297. The core 295 has a tubular profile, and the winding 297 includes an electrical conductor (e.g., copper wire) distributed circumferentially around the core 295, which receives electrical energy to generate a magnetic field for driving the rotor 294 to rotate.

[0077] In the illustrated embodiment, one or more conduits 211 are provided as part of the cooling system 210 for directing cooling fluid from the heat exchanger 214 to the drive unit 206 and / or the drive train 208. The conduits 211 can be configured to transfer the cooling fluid into the internal passages of the drive unit 206 and / or direct the cooling fluid onto the drive unit 206. In some embodiments, as shown in FIG. Fig.23 shown and in Fig. 27 2, the conduit 211 is coupled to a channel 213 in the housing 203 for passing cooling fluid from the inlet 218 to the drive unit 206 and / or the drive train 208. In some embodiments, similar to the channel 13 through the housing 103 described above, the channel 213 can be formed through the housing 203. The channel 213 in the housing 203 extends along and through a portion of the housing 203 to distribute the cooling fluid to the conduit 211 and otherwise circulate the cooling fluid around the drive assembly 204. The channel 213 can be formed, for example, as part of a casting process or post-processing of the housing 203. In some embodiments, the channel 213 of the housing 203 is used without the conduit 211. In some embodiments, the conduit 211 is used without the channel 213. In some embodiments, one or more rings 217 are configured to receive the cooling fluid and distribute the cooling fluid around the stator 292 and / or the rotor 294, for example, to distribute the cooling fluid to the channel in the drive unit 206. In some embodiments, cover 298 may be coupled to housing 203 and configured to receive cooling fluid from passage 213 of housing 203 and deliver the cooling fluid to rotor 294 and / or stator 292 of drive unit 206 .

[0078] In an exemplary embodiment, conduit 211 may include one or more core sprayers 221, feed tubes 222, transfer tubes, winding sprayers 224, and other possible conduit configurations for delivering cooling fluid through drive assembly 204, such as Figure 25-29 As shown. The cooling fluid may be supplied to the conduit 211 through one or more of the channels 213 in the housing 203 or may be supplied to the conduit 211 from the pump 212 in other ways. In the illustrative embodiment, the core sprayer 221 is disposed above the drive unit 206 and is in fluid communication with the channel 213 of the housing 103. The core sprayer 221 may be formed to define a plurality of legs ( Fig.25 and 27 ) with one or more of the legs being formed to include one or more outlet holes. The cooling fluid flowing into the core sprayer 221 is distributed into each leg, which feeds a series of outlet holes to spray the cooling fluid onto the core 295 of the stator 292. It is contemplated that the core sprayer 221 may define more or less than three legs. Other configurations are also contemplated. Fig.28 As shown, the feed tube 222 conveys the cooling fluid from the channel 213 of the housing 203 to a ring 217 having one or more internal channels (similar to the ring 17 described above) for distributing the cooling fluid around the drive unit and used by the drive unit 206. In some embodiments, the channels of the ring 217 can be formed as cavities during the molding process, such as by an insert molding process or by a machining operation. The transmission tube (similar to the transmission tube 23 described above) can guide the cooling fluid to the transmission system 208 and other parts of the drive assembly 204.

[0079] The winding sprayer 224 may be disposed above the winding 297 of the drive unit 206 and may be formed to include an outlet hole 226 for spraying a cooling fluid onto the winding 297, such as Fig.25 , 26 and 29. In some embodiments, the winding sprayer 224 is coupled to the ring 217 and receives the cooling fluid from the feed tube 222 through the ring 217. In some embodiments, the winding sprayer 224 is positioned on both sides of each driver. The winding sprayer 224 can be formed with a contoured portion that provides a gap between the winding sprayer 224 and the winding 297. Other configurations can be conceived. In some embodiments, one or more of the channels 213 in the housing 203 define a rear sprayer for spraying cooling fluid onto the winding 297 opposite to the winding sprayer 224 (similar to the rear sprayer 27 described above). In some embodiments, the rear sprayer is formed in the housing 203 along an arc path around the drive unit 206. In some embodiments, the rear sprayer includes a series of outlet holes that are circumferentially distributed around the drive unit 206 above the winding 297 for spraying cooling fluid onto the winding 297. Other configurations can be conceived.

[0080] In the illustrated embodiment, each ring 217 further functions as a clamping ring to hold the corresponding drive unit 206 to the housing 203, such as Fig.29 As shown. For example, fasteners such as studs 291 and nuts 293 engage with the clamping ring 217 and the housing 203 to hold the drive unit 206 on the housing 203. The studs 291 are distributed circumferentially around the drive unit 206 and extend through the clamping ring 217 to engage with the housing 203, such as through mating threads on the studs 291 and the housing 203. The nuts 293 engage with the studs 291, such as through mating threads on the studs 291 and the nuts 293, and engage with the clamping ring 217 to press the clamping ring 217 against the stator 292 and the stator 292 against the housing 203. The clamping ring 217 evenly distributes the clamping force from the fasteners around the stator 292. In some embodiments, the studs 291 extend through the stator 292. The clamping ring 217 can be formed as a single component or in multiple sections assembled together.

[0081] The conduits 211 , channels 213 , and other structures described herein and contemplated by the present disclosure for moving cooling fluid through the drive assembly 204 may be collectively referred to as a fluid delivery network 260 of the cooling system 210 .

[0082] exist Fig.31 Another embodiment of an electric wheel axle assembly 300 according to the present disclosure is shown in FIG. Figure 1-13 The electric axle assembly 300 is similar to the electric axle assembly 100 shown and described above, wherein similar reference numerals after the numeral 300 are used to identify similar structures in the electric axle assembly 300 as the electric axle assembly 100. The electric axle assembly 300 includes a suspension frame 302 and a pair of drive assemblies 304 coupled to opposite sides of the suspension frame 302. A controller 305 controls the operation of the electric axle assembly 300. Each of the drive assemblies 304 includes a drive unit 306 (e.g., an electric motor) and a transmission 308. The drive unit 306 and the transmission 308 are housed in a housing 303 of the transmission assembly 304. A wheel hub 309 allows a wheel to be attached to the transmission assembly 304 for rotation with the rotation of the transmission 308. The drive unit 306 provides motive force to the wheels through the transmission 308 for propelling the vehicle along the ground.

[0083] In the illustrated embodiment, each drive assembly 304 is provided with a cooling system 310 according to the present disclosure that circulates a cooling fluid, such as oil, transmission fluid, or other substantially non-conductive fluid, through the drive assembly. Figure 31-42 As shown. Fig.32As shown, each cooling system 310 includes a pump 312 and a heat exchanger 314. The pump 12 can be driven by a drive unit 306 and / or a transmission 308 and / or by a separate drive device. The pump 312 moves the cooling fluid through the housing 303 of the drive assembly 304 to cool and / or lubricate the drive unit 306 and / or the transmission 308. The cooling fluid passes through the heat exchanger 314, and the exchange medium (such as water or antifreeze) flows through the heat exchanger 314 in a parallel flow or reverse flow mode to reach the cooling fluid for absorbing heat from the cooling fluid to the exchange medium. The exchange medium can be supplied to the heat exchanger 314 by a conduit 342 and removed from the heat exchanger 314. In some embodiments, the exchange medium can be used in another cooling system at other locations of the vehicle to cool other vehicle components, such as batteries and / or power inverters. In some embodiments, the heat exchanger 14 is an air-cooled heat exchanger. In some embodiments, a plurality of pumps 12 and / or heat exchangers 14 can be used.

[0084] The cooling fluid flows onto or into the drive unit 306 and / or the transmission 308 and flows downwardly to a lower portion of the housing 303 (e.g., near the suspension frame 302), which defines a sump 307 for collecting the cooling fluid, such as Fig.33 In the illustrated embodiment, the pump 312 includes a first pump 344 and a second pump 346. The first pump 344 may be driven by a drive device 348 such as an electric motor, and the second pump 346 may be driven by a drive device 348 such as an electric motor. Figure 33-35 33-35. In some embodiments, the first pump 344 operates to circulate cooling fluid continuously through the housing 303 and the second pump 346 provides additional cooling fluid flow during operation of the drive unit 306. In some embodiments, the first pump 344 operates during idle periods of the drive unit 306 to circulate cooling fluid and stops operating in favor of the second pump 346 as the drive unit 306 operates. In some embodiments, the first pump 344 operates when the drive unit 306 is operating below a certain threshold (e.g., rotational speed, power level, etc.).

[0085] Aspirator 315 may be disposed in sump 307 and fluidly coupled to first pump 344 and second pump 346 (eg, via conduit 316) to draw cooling fluid from sump 307 for recirculation through housing 303, such as Figure 33-35As shown. Filter 349 can be configured to receive the cooling fluid moved by pumps 344, 346 for clearing debris from the cooling fluid. Filter 349 can be mounted on the outside of housing 303 for replacement. In some embodiments, aspirator 315 includes a filter to clear debris from the cooling fluid. One or more gears of transmission 308 can extend into sump 307 to spread cooling fluid to other gears of transmission 308. The rotation of the gears can also splash cooling fluid throughout housing 303 to lubricate contact surfaces.

[0086] exist Fig.33 and 39 An exemplary drive unit 306 is shown in FIG. The drive unit 306 can be constructed similarly to the drive units 106, 206 described above. The drive unit 306 includes a stator 392 and a rotor 394. The stator 392 is coupled to the housing 303 of the drive assembly 304, and the rotor 394 is configured to rotate relative to the stator 392. A pinion 396 is coupled to the rotor 392 and engages with the drive train 308 for transmitting motive force from the drive unit 306 to the drive train 308. In some embodiments, the drive unit 306 includes internal passages in the stator 392 and / or the rotor 394 to allow a cooling fluid to flow through the drive unit 306. The stator 392 includes a core 395 and a winding 397, such as Fig.33 shown.

[0087] In the illustrated embodiment, the cooling system 310 further includes a plurality of conduits 311 disposed in the housing 303 and channels 313 formed through the housing 303 for circulating a cooling fluid, such as Figure 36-42As shown. Conduit 311 and channel 313 direct cooling fluid from heat exchanger 314 to drive unit 306 and / or drive train 308. Conduit 311 can be configured to transfer cooling fluid into an internal channel of drive unit 306 and / or direct cooling fluid onto drive unit 306. In some embodiments, conduit 311 is coupled to channel 313 in housing 303 to transfer cooling fluid from heat exchanger 314 to drive unit 306 and / or drive train 308. Channel 313 extends along and through a portion of housing 303 to distribute cooling fluid to conduit 311 and otherwise circulate cooling fluid around drive assembly 304. Channel 313 can be formed as part of a casting process or post-processing of housing 303, for example. In some embodiments, channel 313 of housing 103 is used without conduit 311. In some embodiments, conduit 311 is used without channel 313. In some embodiments, one or more rings 317 are configured to receive and distribute cooling fluid around stator 392 and / or rotor 394, such as for distributing cooling fluid to channels in drive unit 306. In the illustrated embodiment, ring 317 also functions as a clamping ring for holding drive unit 306 to housing 303. For example, fasteners such as studs and nuts engage clamping ring 317 and housing 303 to hold drive unit 306 to housing 303, as described in detail herein.

[0088] An exemplary flow path of the exchange medium through the heat exchanger 314 is as follows: Fig.36 and 37 The exchange medium enters the housing 303 through one of the conduits 342, passes upward through the heat exchanger 314, and then passes downward through the channel 352 of the housing 303 to the other conduit 342. An exemplary flow path of the cooling fluid through the heat exchanger 314 is schematically indicated by arrows 343. The cooling fluid is discharged from the channel 354 ( Fig.37 ) upwardly into and through the heat exchanger 314 and through passages 356, 358 ( Fig.38 ) downwardly into the housing 303 for circulation through the housing 303. In some embodiments, a portion of the cooling fluid may be passed through the inlet 351 and the channel 353 ( Fig.42 ) is circulated to the cover 298 coupled to the housing 303 for distribution to the drive unit 306, as Fig.36 As shown by arrow 345 in FIG.

[0089] like Fig.40As shown, first pump 344 and second pump 346 move cooling fluid into channel 350 for distribution to channel 354 into heat exchanger 314. In some embodiments, the cooling fluid moved by pump 346 passes through and / or around pump 344 into channel 350. Fluid flow ( Fig.41 343 in FIG. 3) into channel 358 as indicated by arrow 347. In the illustrated embodiment, one or more of conduits 311 are configured to circulate cooling fluid from channel 358 around housing 303. For example, conduits 311 may include one or more core sprayers 321, feed tubes 322, transfer tubes 323, winding sprayers, and other cooling devices as described in detail herein. Fig.41 Other possible conduit configurations are shown for delivering cooling fluid through drive assembly 304. In some embodiments, one or more of passages 313 in housing 303 define one or more winding sprayers for spraying cooling fluid onto windings 397 of drive unit 306, as described in detail herein.

[0090] The conduits 311 , channels 313 , and other structures described herein and contemplated by the present disclosure for moving cooling fluid through the drive assembly 304 may be collectively referred to as a fluid delivery network 360 of the cooling system 310 .

[0091] Another embodiment of the electric wheel axle assembly 400 according to the present disclosure is Fig.43 The electric wheel axle assembly 400 is similar to Figure 14-30 The electric wheel axle assembly 200 shown and described above, wherein similar reference numerals after the numeral 400 are used to identify similar structures in the electric wheel axle assembly 400 to the electric wheel axle assembly 200. The electric wheel axle assembly 400 includes a drive assembly 404 and an axle tube 402 extending from opposite sides of the drive assembly 404. A controller 405 controls the operation of the electric wheel axle assembly 400. The drive assembly 404 includes a drive input 430 and a transmission 408. In the illustrative embodiment, the drive input 430 includes a pair of drive units 406, such as electric motors. The drive units 406 and the transmission 408 are housed in a housing 403 of the transmission assembly 404. The transmission 408 extends through the axle tube 402 to engage with a wheel hub 409. The wheel hub 409 allows the wheels to be attached to the transmission assembly 404 for rotation as the transmission 408 rotates through the drive input 430. The drive unit 406 provides motive force to the wheels through the transmission 408 for propelling the vehicle along the ground.

[0092] The cooling system 410 according to the present disclosure circulates a cooling fluid such as oil, transmission fluid, or other substantially non-conductive fluid to the drive assembly 404, such as Figure 43-46During operation, the cooling fluid circulated by the cooling system 410 controls the heat generated by the drive unit 406. In the illustrated embodiment, the cooling system 410 includes a pump 412 and a heat exchanger 414. The pump 412 moves the cooling fluid from the housing 403 through the heat exchanger 414 (e.g., Fig.44 443 in the figure) and returns to the housing 403 through one or more inlets 462, 464, 466, 468 (as schematically shown by arrows 445) for circulation to the drive unit 406 and / or the transmission 408. The pump 412 can be driven by one of the drive unit 406 and / or the transmission 408 and / or by a separate drive device. In the illustrative embodiment, the pump 412 includes a pump 444 operated by one or more drive devices 446, 448. For example, the drive device 446 can be engaged with the transmission 408 ( Fig.47 ) to convey motive force from the drive unit 406 to the pump 444 during operation of the drive unit 406. The drive device 448 can be an electric motor and operates in addition to or in place of the drive device 446. For example, in some embodiments, the drive device 446 operates the pump 444 to continuously circulate the cooling fluid through the housing 403, and the drive device 448 provides additional cooling fluid flow during operation of the drive unit 406. In some embodiments, the drive device 446 operates the pump 444 during an idle period of the drive unit 406 to circulate the cooling fluid and stops operating the drive device 448 as the operation of the drive unit 406 facilitates operation. In some embodiments, the drive device 446 operates the pump 444 when the drive unit 406 is operating below a certain threshold (e.g., rotational speed, power level, etc.).

[0093] like Fig.44 As shown, the cooling fluid passes through the heat exchanger 414 to remove heat from the cooling fluid. The cooling fluid passes through one or more conduits (schematically represented by arrows 445) and enters the housing 403 inlet 462, 464, 466, 466, 468. The coolant is distributed through the housing 403 for cooling and / or lubricating the drive unit 406 and / or the transmission 408. In an illustrative embodiment, the heat exchanger 414 is a liquid-cooled heat exchanger, which allows an exchange medium such as water or antifreeze to flow through the fitting 454 in parallel or reverse flow to draw heat from the cooling fluid into the exchange medium. In some embodiments, the exchange medium can be used in another cooling system at other locations of the vehicle to cool other vehicle components, such as batteries and / or power inverters. In some embodiments, the heat exchanger 414 is an air-cooled heat exchanger. In some embodiments, a plurality of pumps 412 and / or heat exchangers 414 can be used. In some embodiments, each drive unit 406 is provided with its own cooling system 410.

[0094] The cooling fluid flows onto and / or into the drive unit 406 and / or the transmission 408 and flows downward to the lower portion of the housing 403 (e.g., below the axle tube 402), which defines a sump 407 for collecting the cooling fluid. Figure 45-49 In some embodiments, the aspirator 415 is disposed in the liquid collecting portion 407 and is fluidly coupled to a pump 444 (eg, via a conduit 416) to extract cooling fluid from the housing 403 for recirculation, as shown. Fig.45 and 46 In some embodiments, the aspirator 415 includes a filter to remove debris from the cooling fluid. In some embodiments, the filter 449 is connected to the cooling system 410 outside the housing 403 for replacement. Fig.47 As shown, one or more gears of the transmission 408 may extend into the sump 407 to spread cooling fluid to other gears of the transmission 408. The rotation of the gears may also splash cooling fluid throughout the housing 403 for lubricating contact surfaces.

[0095] The exemplary drive unit 406 is Fig.45 and 47 406 is shown in cross section. The drive unit 406 can be configured similarly to the drive units 106, 206, 306 described above. In an illustrative embodiment, the drive units 406 each include a stator 492 and a rotor 494. The stator 492 is coupled to the housing 403 of the drive assembly 404, and the rotor 494 is configured to rotate relative to the stator 492. The pinion 496 is coupled to the rotor 494 and engages with the transmission 408 for transmitting the motive force from the drive unit 406 to the transmission 408. In some embodiments, the drive unit 406 includes internal passages located in the stator 492 and / or the rotor 494 for cooling fluid to flow through the drive unit 406. The stator 492 includes a core 495 and a winding 497.

[0096] In the illustrative embodiment, one or more conduits 411 are provided as part of the cooling system 410 for directing cooling fluid from the heat exchanger 414 to the drive unit 406 and / or the drive train 408. The conduits 411 can be provided to transfer the cooling fluid into the internal passages of the drive unit 406 and / or to direct the cooling fluid onto the drive unit 406. In some embodiments, the conduits 411 are coupled to the passages 413 in the housing 403 to transfer the cooling fluid from the inlets 462, 464, 466, 468 to the drive unit 406 and / or the drive train 408, as shown in FIG. Fig.45 and 48-50. In some embodiments, a channel 413 may be formed through the housing 403, similar to the channels 13, 213, 313 through the housings 103, 203, 303 described above. The channel 413 in the housing 403 extends along and through a portion of the housing 403 to distribute the cooling fluid to the conduit 411 and otherwise circulate the cooling fluid around the drive assembly 404. The channel 413 may be formed as part of a casting process or post-processing of the housing 403, for example. In some embodiments, the channel 413 of the housing 403 is used without the conduit 411. In some embodiments, the conduit 411 is used without the channel 413. In some embodiments, one or more rings 417 are configured to receive the cooling fluid and distribute the cooling fluid around the stator 492 and / or the rotor 494, for example, to distribute the cooling fluid to a channel in the drive unit 406. In some embodiments, cover 498 can be coupled to housing 403 and configured to receive a charge from passages 413 of housing 403 (e.g., passage 453 supplied by inlet 464 and passage 455 supplied by inlet 462, such as Fig.48 and 50 ) receives cooling fluid and delivers the cooling fluid to the rotor 494 and / or stator 492 of the drive unit 406.

[0097] In an exemplary embodiment, conduit 411 may include one or more core sprayers, feed tubes 422, transfer tubes, winding sprayers, and other possible conduit configurations for delivering cooling fluid through drive assembly 404 as described in detail herein. Fig.45 and 47 -50. The cooling fluid may be supplied to the conduit 411 through one or more of the passages 413 in the housing 403 or otherwise supplied from the pump 412 to the conduit 411. In the illustrated embodiment, the feed tube 422 connects the inlet 462, 466 and the passages 413 (e.g. Fig.49 458 shown in the embodiment of the present invention is communicated to a ring 417 having one or more internal channels (similar to the above-described ring 17) for distributing the cooling fluid around the drive unit 406 and for use by the drive unit 406. In some embodiments, the channels of the ring 417 can be formed as cavities during a molding process, for example, using an insert molding process or a machining operation. In some embodiments, one or more of the channels 413 in the housing 403 define a winding sprayer 427 for spraying cooling fluid onto the windings 497 of the drive unit 406. In some embodiments, the winding sprayer 427 is formed in the housing 403 along an arc path around the drive unit 406. In some embodiments, the winding sprayer 427 includes a series of outlet holes distributed circumferentially around the drive unit 406 above the windings 497 for spraying cooling fluid onto the windings 497. Other configurations are contemplated.

[0098] In the illustrated embodiment, each ring 417 further functions as a clamping ring for holding the corresponding drive unit 406 to the housing 403, such as Fig.46 As shown. For example, fasteners such as studs 491 and nuts 493 engage with the clamping ring 417 and the housing 403 to hold the drive unit 406 on the housing 403. The studs 491 are distributed circumferentially around the drive unit 406 and extend through the clamping ring 417 to engage with the housing 403, such as through mating threads on the studs 491 and the housing 403. The nuts 493 engage with the studs 491, such as through mating threads on the studs 491 and the nuts 493, and engage with the clamping ring 417 to press the clamping ring 417 against the stator 492 and the stator 492 against the housing 403. The clamping ring 417 evenly distributes the clamping force from the fasteners around the stator 492. In some embodiments, the studs 491 extend through the stator 492. The clamping ring 417 can be formed as a single component or multiple parts assembled together.

[0099] The conduits 411 , channels 413 , and other structures described herein and contemplated by the present disclosure for moving cooling fluid through the drive assembly 404 may be collectively referred to as a fluid delivery network 460 of the cooling system 410 .

[0100] The descriptions of the various embodiments of the electric axle assembly herein may be combined by reference to each other.

[0101] In an illustrative embodiment, an electric wheel axle assembly according to the present disclosure may be configured for use with a vehicle such as a frame truck. Wheels are arranged at opposite ends of the electric wheel axle assembly to support the vehicle to run along the ground surface. The electric wheel axle assembly propels the vehicle by transmitting motive force to the wheels in contact with the ground surface. The vehicle may include a chassis on which a vehicle body and other equipment may be supported. For example, a cab, a cargo box, a boom, or a hook system may be mounted to the chassis. The chassis may include frame rails; suspension components (e.g., springs, shock absorbers, and trailing arms); and brake components (e.g., cylinders, brake calipers, brake rotors, brake drums, brake hoses, etc.). The electric wheel axle assembly may be mounted perpendicular to the frame rails so that the vehicle travels in a direction aligned with the frame rails.

[0102] In illustrative embodiments, the electric wheel axle assembly can be configured for "single wheel" applications and "dual wheel" applications. In the "single wheel" application, a single wheel is connected to each end of the electric wheel axle assembly. Similarly, in the "dual wheel" application, the wheels are arranged in pairs at both ends of the electric wheel axle assembly. A vehicle that requires increased payload or traction capacity is an example of a "dual wheel" application. Vehicles that require further increased payload / traction capacity can be equipped with two or more electric wheel axle assemblies. Some vehicles may require drive devices other than wheels. For example, tracks or guide wheels can be connected to the electric wheel axle assembly to propel the vehicle. The electric wheel axle assembly can be mounted to the vehicle at the front and rear to achieve various drive types (e.g., front wheel drive, rear wheel drive, and full / four wheel drive).

[0103] In an illustrative embodiment, vehicle performance is optimized when the wheels are in constant contact with the ground. To more easily follow the ground, a suspension system may movably couple the electric axle assembly to the frame rails. The suspension system allows the electric axle assembly to move relative to the frame rails and push the wheels toward the ground when the vehicle encounters ground imperfections. The suspension system may include springs and shock absorbers that absorb motion and improve ride quality; control arms that limit electric axle assembly motion; and other elements determined by the application, such as steering and kinematic linkages. The electric axle assembly may also be installed to vehicles that were not originally equipped with the electric axle assembly. The electric axle assembly may be retrofitted to these vehicles to provide an electric driveline upgrade.

[0104] In an illustrative embodiment, the electric axle assembly can be used in a hybrid electric vehicle and an all-electric vehicle. In an all-electric vehicle, the electricity used to power the electric axle assembly can be stored in a battery mounted to the chassis. Alternatively, the electricity can be supplied from an external power source such as an overhead line or a third rail system. If the vehicle is configured as a hybrid vehicle, an internal combustion engine can be mounted to the chassis and coupled to a drive unit capable of generating electricity; therefore, the electricity can directly power the electric axle assembly or can be stored in the battery.

[0105] In an illustrative embodiment, the electric wheel axle assembly may include a drive housing (sometimes referred to as a housing) that accommodates at least one drive unit and drives a gear train (sometimes referred to as a transmission). The drive unit is coupled to the drive housing and engages with the gear train to transmit power to the wheel. The gear train may include a series of gears and shafts supported for rotation within the drive housing. Typically, bearings are used to reduce friction between rotating components of the gear train. Depending on the requirements of the application, various bearing types may be used, such as journal (sliding) bearings, roller bearings, ball bearings, etc. Friction is further reduced by using a lubricant (e.g., oil supplied to the contact surfaces between components (e.g., gear teeth and bearings)) to prevent wear and reduce heat. The electric wheel axle assembly may further include two wheel ends (sometimes referred to as hubs) coupled to the drive housing. It should be understood that the drive housing and the wheel ends may be constructed and coupled in various ways. The electric wheel axle assembly may be configured for a low-floor bus and include a plurality of drive housings, each of which is disposed on opposite sides of the electric wheel axle assembly. Fasteners, etc., may be used to assemble the drive housing. The electric wheel axle assembly may include a single drive housing configured to support a plurality of drive units.

[0106] In an illustrative embodiment, the drive unit includes a rotor and a stator. The rotor is supported by bearings in a drive housing for rotation about a rotor axis. The stator is coupled to the drive housing and is disposed around the rotor so that the rotor rotates within the stator. During operation, the drive unit of the electric wheel axle assembly generates heat primarily through friction between contact surfaces and current flowing through the motor windings. A cooling system that removes heat from the drive unit during operation improves the performance of the drive unit. The cooling system may include a coolant fluid, a pump, and a heat exchanger. The cooling system reduces the temperature of the electric wheel axle assembly by pumping the coolant fluid through the heat exchanger and distributing the coolant fluid to the drive unit.

[0107] In an illustrative embodiment, oil used to lubricate the electric wheel axle assembly is used as a coolant fluid. The oil is non-conductive, which allows the oil to contact the high-voltage portion of the drive unit. The oil is pumped through the cooling system and supplied to the drive unit and the contact surfaces of the gear train. The pump can be an oil pump that pumps oil from a pump inlet to a pump outlet. The oil is pumped to a heat exchanger and a supply line to direct the oil toward the desired components in the drive housing. The oil pump can be driven by a separate motor or can be driven by the gear train. In some embodiments, the cooling system may include two pumps, each driven by a corresponding motor.

[0108] In an illustrative embodiment, a heat exchanger cools the oil by transferring heat to a second coolant fluid. The heat exchanger is disposed downstream of the pump and removes heat from the oil. In some embodiments, more than one heat exchanger may be implemented, such as in an axle having two independent cooling systems, or for increasing the cooling capacity of a cooling system. The heat exchanger may utilize a variety of fluids as the second coolant fluid, such as water or antifreeze. The heat exchanger may further be configured as a radiator to cool the oil using a flowing air source. In addition, the heat removal requirements of the heat exchanger may allow the use of a finned oil tank to cool the oil without air flow. Further, it is contemplated that the cooling system may include a thermostat disposed between the oil pump and the heat exchanger to prevent the oil from flowing into the heat exchanger until a predetermined temperature is reached.

[0109] In an illustrative embodiment, oil is supplied to the pump from an oil sump in each housing via a corresponding aspirator tube that is fluidly coupled to the pump inlet. The aspirator tube may include an aspirator screen or filter element to help prevent contaminants that have settled in the oil sump from reaching the pump. The oil in the sump flows through each aspirator tube and enters the pump, which pumps the oil out of each pump outlet and into an auxiliary line. The auxiliary line delivers the oil to a distribution manifold where the flow is merged into an outlet line coupled between the distribution manifold and the heat exchanger. The heat exchanger may have an inlet and an outlet, wherein the inlet is configured to receive oil from the pump and the outlet is coupled to a housing shell gallery (sometimes referred to as a channel) defined in the drive housing.

[0110] In the illustrative embodiment, the cooled oil from the heat exchanger flows into the housing gallery, which can be implemented as one or more passages formed in the housing shell by casting or machining. Each passage transports the oil from the housing gallery inlet to one or more housing gallery outlets for further distribution inside the drive housing.

[0111] In an illustrative embodiment, the clamping ring includes an upper portion and a lower portion that interlock to form a ring. Each portion defines a plurality of mounting holes that receive threaded fasteners for coupling the drive unit to the drive housing. In some embodiments, the clamping ring is formed from a polymer or composite material, such as by an injection molding process. In some embodiments, the clamping ring is formed from a fiber reinforced polymer, such as glass filled nylon. Other materials, such as metals and alloys, and processes, such as casting or forging, are contemplated.

[0112] In an illustrative embodiment, the cooling system also includes a jumper tube that transfers oil between the housing shell gallery and the clamping ring gallery. The jumper tube extends between a first end coupled to the housing shell in fluid communication with the housing shell gallery and a second end coupled to the clamping ring in fluid communication with the clamping ring gallery. Oil flows from one of the housing shell gallery outlets through the jumper tube into the clamping ring gallery.

[0113] In an illustrative embodiment, the cooling system further includes a winding sprayer disposed above the winding of the drive unit and coupled to a clamping ring in fluid communication with one of the clamping ring gallery outlets. The winding sprayer is formed with a contoured portion that provides a gap between the winding sprayer and the winding. A series of outlet holes are defined in the winding sprayer that direct oil onto the winding. The oil flows from the clamping ring gallery outlet through the winding sprayer to the series of outlet holes. Other configurations are contemplated.

[0114] In an illustrative embodiment, the cooling system further includes a rear sprayer. The rear sprayer may be defined in the housing along an arc path around the drive unit. The rear sprayer may include a series of outlet holes in fluid communication with one of the housing gallery outlets and disposed above the winding protruding from the second end of the stator. Oil flows from the housing gallery outlet through the rear sprayer to the series of outlet holes. Other configurations are contemplated.

[0115] In an illustrative embodiment, the electric wheel axle assembly may include a gear baffle disposed in the oil collecting portion and coupled to the housing shell. The gear baffle has a semicircular profile with an open end configured to receive a portion of one of the gears of the gear train. The gear baffle protrudes into the oil collecting portion with the open end positioned above the oil to prevent oil from accumulating in the gear baffle. The gear baffle forms notches for the gears that partially protrude into the oil collecting portion to rotate without skimming the oil, thereby reducing churning losses and oil foaming.

[0116] Although the present disclosure has been shown and described in detail in the drawings and foregoing description, such illustration and description should be considered illustrative rather than restrictive, and it should be understood that only exemplary embodiments are shown and described and that all changes and modifications within the spirit of the present disclosure are intended to be protected.

Claims

1. An electric wheel axle assembly, comprising: case; a drive assembly housed in the housing, the drive assembly comprising a first drive unit, a second drive unit, and a drive train, wherein each of the first drive unit and the second drive unit is engaged with the drive train and is configured to provide motive force to the drive train; a pair of axle tubes attached to and extending from opposite sides of the housing; as well as a cooling system coupled to the drive assembly, wherein the cooling system includes a pump, a heat exchanger, and a fluid delivery network, wherein the pump is configured to transfer a cooling fluid from the housing to the heat exchanger, the heat exchanger is configured to extract heat from the cooling fluid, and the fluid delivery network is configured to transfer the cooling fluid from the heat exchanger to the housing, The fluid transport network includes a plurality of channels formed in the housing to receive the cooling fluid from the heat exchanger and a plurality of conduits fluidly connected to the plurality of channels, wherein the plurality of conduits are configured to direct the cooling fluid received from the plurality of channels to at least one of the first drive unit, the second drive unit, and the transmission system.

2. The electric wheel axle assembly of claim 1 , wherein the first drive unit and the second drive unit each include an internal passage, and wherein the plurality of conduits include a first conduit and a second conduit, wherein the first conduit is fluidly connected to the internal passage of the first drive unit to guide the cooling fluid into the internal passage of the first drive unit, and the second conduit is fluidly connected to the internal passage of the second drive unit to guide the cooling fluid into the internal passage of the second drive unit.

3. The electric wheel axle assembly of claim 2, wherein the first drive unit comprises a first stator and a first rotor, the first stator comprising a first core and a first set of windings coupled to the first core, and The second driving unit includes a second stator and a second rotor, wherein the second stator includes a second core and a first set of windings coupled to the second core. 4 . The electric axle assembly of claim 3 , wherein an internal passage of the first drive unit is formed in the first stator, and an internal passage of the second drive unit is formed in the second stator. 5 . The electric axle assembly of claim 3 , wherein an internal passage of the first drive unit is formed in the first rotor, and an internal passage of the second drive unit is formed in the second rotor.

6. The electric axle assembly of claim 3, wherein the fluid delivery network further comprises a first core sprayer fluidly connected to a first conduit of the plurality of conduits and a second core sprayer fluidly connected to a second conduit of the plurality of conduits, wherein the first core sprayer is configured to receive the cooling fluid from the first conduit and spray the cooling fluid onto the first core of the first drive unit, and The second core sprayer is configured to receive the cooling fluid from the second conduit and spray the cooling fluid onto the second core of the second drive unit.

7. The electric axle assembly of claim 3, wherein the fluid delivery network further comprises a first winding sprayer fluidly connected to a first conduit of the plurality of conduits and positioned above the first set of windings, and a second winding sprayer fluidly connected to a second conduit of the plurality of conduits and positioned above the second set of windings, wherein the first winding sprayer is configured to receive the cooling fluid from the first conduit and spray the cooling fluid onto the first set of windings of the first drive unit, and The second winding sprayer is configured to receive the cooling fluid from the second conduit and spray the cooling fluid onto the second set of windings of the second drive unit.

8. The electric wheel axle assembly according to claim 7, further comprising: a first ring fastened to the housing and comprising an internal passage fluidically connected to a plurality of passages formed in the housing via a first feed tube to receive the cooling fluid from the internal passage, wherein the first winding sprayer is fluidically connected to the internal passage of the first ring, and A second ring is fastened to the housing and includes an internal passage fluidly connected to a plurality of passages formed in the housing via a second feed tube to receive the cooling fluid from the internal passage, wherein the second winding sprayer is fluidly connected to the internal passage of the second ring.

9. The electric axle assembly of claim 7, wherein the fluid delivery network further comprises a first rear sprayer coupled to a third conduit of the plurality of conduits and positioned above the first set of windings, and a second rear sprayer coupled to a fourth conduit of the plurality of conduits and positioned above the second set of windings, wherein the first rear sprayer is configured to receive the cooling fluid from the third conduit and spray the cooling fluid onto a first set of windings of the first drive unit opposite the first winding sprayer, and The second winding sprayer is configured to receive the cooling fluid from the fourth conduit and spray the cooling fluid onto a second set of windings of the second drive unit opposite to the second winding sprayer.

10. The electric wheel axle assembly according to claim 3, further comprising: a first clamping ring including a plurality of internal passages, and wherein, when the first clamping ring is secured to the housing, the first clamping ring engages with and forces a first stator of the first drive unit against the housing, and the plurality of internal passages of the first clamping ring are in fluid communication with passages formed into the housing, and a second clamping ring including a plurality of internal passages, and wherein, when the second clamping ring is secured to the housing, the second clamping ring engages with and holds the second stator of the second drive unit against the housing, and the plurality of internal passages of the second clamping ring are in fluid communication with passages formed into the housing.

11. The electric axle assembly of claim 1 , wherein the plurality of conduits are configured to direct the cooling fluid onto the drive train, wherein the cooling fluid is further configured to lubricate the drive train.

12. The electric axle assembly of claim 1, wherein the housing further comprises a plurality of inlets fluidly connected to further included conduits fluidly connected to a plurality of channels formed in the housing, and Also included is a conduit fluidly connected to the heat exchanger and an inlet of the housing and configured to deliver the cooling fluid from the heat exchanger to the housing.

13. The electric axle assembly of claim 1 , wherein the first drive unit and the second drive unit each include an internal channel, and wherein the electric axle assembly further includes: a first ring coupled to the housing and the first drive unit, the first ring including an internal passage fluidly connected to at least one of a plurality of passages formed in the housing and to an internal passage of the first drive unit, and A second ring is coupled to the housing and the second drive unit, the second ring including an internal passage that is fluidly connected to at least one of a plurality of passages formed in the housing and to an internal passage of the second drive unit.

14. The electric axle assembly of claim 1, wherein the housing is formed to define a sump for collecting cooling fluid, wherein the pump draws the cooling fluid from the sump, and wherein, The cooling fluid is configured to absorb heat from the first drive unit and the second drive unit and flow into the liquid collecting portion.

15. The electric axle assembly of claim 1, wherein the cooling fluid is further configured to lubricate at least one of the drive unit and the drive train.

16. An electric wheel axle assembly, comprising: a housing configured to house at least one drive unit and an associated drive train; at least one inlet formed in the housing and configured to receive a cooling fluid from a cooling system external to the housing; as well as A plurality of channels are formed in the housing, wherein each channel is fluidly connected to the at least one inlet to receive the cooling fluid from the cooling system and direct the cooling fluid around the housing and to at least one of the drive unit and an associated drive train.

17. The electric wheel axle assembly of claim 16, further comprising a plurality of conduits located within the housing and fluidly connected to the plurality of channels, wherein the plurality of conduits are configured to direct cooling fluid received from the plurality of channels to at least one of the drive unit and an associated transmission system.

18. The electric wheel axle assembly of claim 17, further comprising a core sprayer fluidly connected to a first conduit among the plurality of conduits, wherein the core sprayer is configured to receive the cooling fluid from the first conduit and spray the cooling fluid onto a core of a stator of the at least one drive unit.

19. The electric axle assembly of claim 17, further comprising a winding sprayer fluidly connected to a first conduit among the plurality of conduits, wherein the winding sprayer is configured to receive the cooling fluid from the first conduit and spray the cooling fluid onto the windings of the at least one drive unit.

20. The electric axle assembly of claim 17, wherein the housing is formed to define a sump for collecting the cooling fluid.

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