Electric beam type axle

Abstract

An electric beam axle having a central tube disposed coaxially about an output axis and a pair of drive units each including: a housing assembly fixedly coupled to the central tube; a motor assembly coupled to the housing assembly and having a motor output shaft rotatable about a motor axis; a hub assembly fixedly coupled to the housing assembly and having a hub rotatable about an output axis; and a transmission. The housing assembly has a tube mount defining a bore in which the central tube is received and defining a cavity. The motor output shaft extends to the cavity. A transmission drivingly connects the motor output shaft to the hub to transfer rotational power between the motor and the hub. The output axis is offset from the motor axis.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 404,654, filed on September 8, 2022, the disclosure of which is incorporated herein by reference as if set forth in full herein. Technical Field

[0003] This disclosure relates to an electric beam axle. Background Art

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

[0005] International Patent Application No. PCT / US2002 / 019900 discloses various configurations for relatively robust electric beam axles. While such configurations are well - suited for their intended purposes, we note that there are situations where additional ground clearance is needed, such as in the area of an electric beam axle that includes a carrier housing and a differential assembly. Accordingly, there is a need in the art for an improved electric beam axle. Summary of the Invention

[0006] This section provides a general overview of the present disclosure and is not an exhaustive disclosure of its full scope or all of its features.

[0007] In one form, the present disclosure provides an electric beam axle that includes a center tube and a pair of drive units. The center tube has opposite axial ends and is disposed coaxially about an output axis. Each drive unit has a housing assembly, a motor assembly, a wheel hub assembly, and a transmission. The housing assembly has a tube mount and defines a cavity. The tube mount defines a tube bore. The center tube is received in the tube bore and fixedly coupled to the tube mount. The motor assembly has a motor with a motor output shaft that is rotatable about a motor axis. The motor assembly is coupled to the housing assembly. The motor output shaft extends into the cavity in the housing assembly. The wheel hub assembly is fixedly coupled to the housing assembly and has a wheel hub that is rotatable about the output axis. The transmission drivingly connects the motor output shaft to the wheel hub to transfer rotational power between the motor and the wheel hub. The output axis is offset from the motor axis.

[0008] In some examples, the housing assembly includes a housing member and an end cap that are joined to each other in a plane perpendicular to the output axis. The housing member includes a motor mounting flange to which the motor is mounted, and the end cap has a hole in which the wheel hub assembly is mounted.

[0009] In other examples, the wheel hub assembly further includes a wheel hub mount and a stub shaft. The wheel hub mount is mounted to the housing assembly. The stub shaft rotatably couples the output gear of the transmission and the wheel hub. Optionally, the electric beam axle can further include a pair of tapered roller bearings, where each tapered roller bearing is mounted at an associated axial end of the output gear and supports the output gear for rotation relative to the housing assembly about the output axis. Also optionally, the wheel hub is supported for rotation relative to the wheel hub mount about the output axis on a pair of tapered roller bearings. As another alternative, the wheel hub includes a wheel hub flange, and the wheel hub assembly further includes an outer hub seal disposed along the output axis between the wheel hub flange and the tapered roller bearing. As yet another alternative, the wheel hub assembly includes a sealing member circumferentially disposed between the wheel hub mount and the inner surface of the hole in the end cap. As a further alternative, the stub shaft includes a first external spline section and a second external spline section, the first external spline section engaging a first internal spline section on the output gear, and the second external spline section engaging a second internal spline section on the wheel hub.

[0010] In another example, the transmission includes: an input gear coupled to the motor output shaft to rotate therewith; and a pair of compound gears. Each compound gear has a first reduction gear meshing with the input gear. Optionally, the transmission further includes an output gear, each compound gear having a second reduction gear coupled to rotate with the first reduction gear, and each second reduction gear meshing with the output gear.

[0011] In yet another example, each motor has a motor housing, and each drive unit further includes an inverter electrically coupled to the motor and mounted to the motor housing.

[0012] In a further example, each motor has a motor housing, and each drive unit further includes a heat exchanger fluidly coupled to the motor and mounted to the motor housing.

[0013] In a further example, the transmission of each drive unit has an output gear, and the electric beam axle includes a first stub shaft, a second stub shaft, and a coupling. The first stub shaft is received in the center tube and is coupled to rotate with the output gear of the first of the drive units. The second stub shaft is coupled to rotate with the output gear of the second of the drive units, and the coupling is selectively operable to rotatably couple the first stub shaft and the second stub shaft. Optionally, the coupling is a clutch, such as a jaw clutch.

[0014] Further applicable fields will become apparent from the description provided herein. The description and specific examples in this summary are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Description of the Drawings

[0015] The drawings described herein are for illustrative purposes only for the selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

[0016] Figure 1 Perspective view of an exemplary electric beam axle constructed in accordance with the teachings of the present disclosure;

[0017] Figure 2 And Figure 3 Is Figure 1 Exploded perspective view of a portion of the electric beam axle, showing in more detail a portion of the drive unit and the center tube assembly;

[0018] Figure 4 And Figure 5 Is Figure 1 Perspective view of a portion of the electric beam axle, illustrating the housing member of one of the drive units;

[0019] Figure 6 Side view of the housing member;

[0020] Figure 7 Is Figure 6 Cross-sectional view taken along line 7-7 in

[0021] Figure 8 、 Figure 9 And Figure 10 Is Figure 1 Perspective view of a portion of the electric beam axle, illustrating the end cap of one of the drive units;

[0022] Figure 11 Side view of the end cap;

[0023] Figure 12 Is Figure 1 Perspective view of a portion of the electric beam axle, illustrating the motor assembly and transmission of one of the drive units;

[0024] Figure 13 Is Figure 1 Cross-sectional view taken along line 13-13 in

[0025] Figure 14 Is Figure 1 Perspective view of a portion of the electric beam axle, illustrating the motor assembly, transmission, and wheel hub assembly of one of the drive units;

[0026] Figure 15 Is Figure 1 Cross-sectional view taken along line 15-15 in

[0027] Figure 16 Is Figure 1 Cross-sectional view taken along line 16-16 in; and

[0028] Figure 17 Schematic diagram of a second exemplary electric beam axle constructed in accordance with the teachings of the present disclosure.

[0029] Throughout several views of the drawings, corresponding reference numerals indicate corresponding components. Detailed Description

[0030] Referring to the accompanying drawings Figure 1 , an exemplary electric beam axle constructed in accordance with the teachings of the present disclosure is generally indicated by reference numeral 10. The electric beam axle 10 may include a pair of drive units 12a, 12b and a center tube assembly 14.

[0031] Since the drive units 12a, 12b are generally similar, the discussion of drive unit 12a will be sufficient for drive unit 12b. The drive unit 12a may include a housing assembly 20, a motor assembly 22, a transmission 24 and a wheel hub assembly 26.

[0032] Referring to Figure 2 and Figure 3 , the housing assembly 20 may include a housing member 30 and an end cap 32, which may cooperate to define a cavity 34 in which the transmission 24 may be received.

[0033] Referring to Figures 4 to 7 , the housing member 30 may define a gearbox 36, a tube mount 38 and a motor mount 40. The gearbox 36 may open at an outer end or side of the housing member 30 and may define a first flange member 44, which may be disposed around a portion of the cavity 34 defined by the housing member 30. The tube mount 38 has a tubular collar 46, which defines a tube bore 48 opening at an inner end of the housing member 30. Optionally, a plurality of weld plug holes 50 may be formed radially through the tubular collar 46 and may intersect the tube bore 48. The weld plug holes 50 may be spaced around the circumference of the tubular collar 46. The tube bore 48 may be a blind hole or may optionally intersect a portion of the cavity 34 formed by the housing member 30. The motor mount 40 defines a motor mounting flange 54 and a motor output shaft hole 56, which intersects a portion of the cavity 34 formed by the housing member 30. The motor mounting flange 54 faces away from the open end of the gearbox 36.

[0034] Referring to Figures 8 to 11 , the end cap 32 may include a cap portion 60 and a wheel hub mount 62. The cap portion 60 may include a second flange member 66, which is configured to cooperate with the first flange member 44 ( Figure 5 ) to close the open end of the gearbox 36 ( Figure 5)。In the provided example, multiple threaded fasteners 68 are assembled through holes 70 in the second flange member 66 and are threadedly engaged with threaded holes 72 formed in the first flange member 44( Figure 5 )). Figure 5 )。The hub mount 62 can define a pilot hole 80 concentrically disposed about the output axis 82 and a first end wall 84 perpendicular to the output axis 82.

[0035] Returning Figure 2 and Figure 3 , a gasket or seal (not specifically shown) can be disposed between the housing member 30 and the end cap 32 at a desired location (e.g., between the first flange member 44 and the second flange member 66) to assist in sealing the joint between the housing member 30 and the end cap 32. In the provided example, the housing member 30 and the end cap 32 are joined in a plane perpendicular to the output axis 82.

[0036] Referring Figure 12 and Figure 13 , the motor assembly 22 includes a motor 90 having a motor housing 92 and a motor output shaft 94. The motor housing 92 is mounted to the motor mounting flange 54 such that the motor output shaft 94 extends through the motor output shaft hole 56 into the portion of the cavity 34 formed by the gearbox 36. Optionally, the motor assembly 22 can include one or more of an inverter 100, a heat exchanger 102, a fluid pump 104, and a filter mount (not specifically shown). The inverter 100 is configured to control the power supply to the motor 90. The inverter 100 can be coupled or mounted to the motor housing 92 and can be electrically connected to the motor 90. The heat exchanger 102 can be coupled or mounted to the motor housing 92 and can be used to cool a fluid that can circulate through the motor 90 and / or the transmission 24 to cool and / or lubricate the motor 90 and / or the transmission 24. The fluid pump 104 can be coupled to the motor housing 92 or the housing assembly 20 and can provide a source of pressurized fluid that can be used to cool and / or lubricate the motor 90 and / or the transmission 24 and optionally to cool the inverter 100. The filter mount can be coupled to the motor housing 92 and can be in fluid communication with the fluid pump 104. The filter mount can receive a fluid filter (not shown) that can be used to filter the fluid that circulates through the drive unit 12a via the fluid pump 104. In the provided example, the various channels (not specifically shown) that couple the fluid pump 104, the filter mount, and the motor 90 can be integrally formed with the motor housing 92 and / or can be formed as discrete components (i.e., tubes, hoses) coupled to the motor housing 92.

[0037] Referring Figure 14 and Figure 15, the transmission 24 can be any type of transmission for transmitting rotational power between the motor output shaft 94 and the wheel hub assembly 26. In this regard, the transmission 24 can include any number of reduction stages and can be configured as a single-speed transmission or a multi-speed transmission. The transmission 24 can include a drive gear 110, a driven gear 112, and gears (such as a pair of compound gears 114) for transmitting rotational power between the drive gear 110 and the driven gear 112. In the specific example provided, the transmission 24 is configured in the manner described in U.S. Patent No. 11,293,534 to the same assignee. Briefly, the drive gear 110 is the input gear of the transmission 24 and is coupled to the motor output shaft 94 to rotate therewith, and the driven gear 112 is the output gear of the transmission 25 and is rotatable about the output axis 82. Each compound gear 114 can have a shaft member 120, a first reduction gear 122 fixedly coupled to the shaft member 120 and meshing with the drive gear 110, and a second reduction gear 124 fixedly coupled to the shaft member 120 and meshing with the driven gear 112. Each shaft member 120 is rotatable about an intermediate axis 128 that is parallel to and offset from the output axis 82 and the motor axis 130 about which the motor output shaft 94 rotates. In the example provided, the motor shaft 130 coincides with and is offset from the output axis 82.

[0038] Reference Figure 16 , each shaft member 120 can be supported by suitable bearings. In the example provided, a roller bearing 140 is received in a first bearing hole 142 formed in the motor mounting flange 54 and is mounted on the first axial end of a corresponding one of the shaft members 120, while a ball bearing 144 is received in a second bearing hole 146 formed in the cover portion 60 of the end cap 32 and is mounted on the opposite second axial end of a corresponding one of the shaft members 120. In the example shown, the ball bearing 144 is mounted on the second axial end of the shaft member 120 such that the inner bearing race of the ball bearing 144 abuts a shoulder formed on the shaft member 120, a thrust washer or spacer is received on the second axial end of the shaft member 120 and abuts the side of the inner bearing race opposite the shoulder on the shaft member, and a snap ring 152 is received in a snap ring groove formed around the second axial end of the shaft member 120. This assembly is inserted into the second bearing hole 146 formed in the cover portion 60, and a retaining ring 156 is inserted into a retaining ring groove formed in the cover portion 60 concentric with the second bearing hole 146. The housing member 30 can be mounted to the end cap 32 to position the first axial end of the shaft member 120 in the first bearing hole 142. The roller bearing 140 can be mounted on the first axial end of the shaft member 120 and received in the first bearing hole 142. Thereafter, the motor 90 can be mounted to the motor mounting flange 54.

[0039] It will be understood that other bearing configurations may be employed instead of the roller and ball bearing combinations illustrated in the figures and described herein. For example, each shaft member 120 may be supported at its opposite axial ends by tapered roller bearings (not shown).

[0040] The driven gear 112 may be supported for rotation by a pair of bearings, such as a pair of tapered roller bearings 160. The first of the tapered roller bearings 160 may be received in a third bearing bore 162 formed in the wall of the gearbox 36, while the second of the tapered roller bearings 160 may be received in a fourth bearing bore 164 formed in the cover portion 60 of the end cap 32. The fourth bearing bore 164 may be concentric with the pilot bore 80.

[0041] The hub assembly 26 may have a hub housing 170, a hub 172, a pair of tapered roller bearings 174, and an outer hub seal 176. The hub housing 170 may have a body portion 180 and an annular wall 182. The body portion 180 may define a second end wall 190, a first wheel bearing bore 192, and an outer hub seal bore 194. The second end wall 190 is configured to abut a first end wall 84 of a hub mount 62 formed on the end cap 32. The first wheel bearing bore 192 may be formed by a counterbore of a first diameter, while the outer hub seal bore 194 may be formed by a counterbore of a larger second diameter. The annular wall 182 may extend from the second end wall 190 and may define a second wheel bearing bore 200. In the example provided, the annular wall 182 is sized to be received in the pilot bore 80 in the hub mount 62 of the end cap 32 in a manner such that the axes of the first wheel bearing bore 192 and the second wheel bearing bore 200 are aligned with the output axis 82. A gasket or seal may be used to seal the joint between the end cap 32 and the hub housing 170. The gasket or seal may be used between the first end wall 84 and the second end wall 190. In the example provided, a suitable sealing member 210, such as an O-ring, is received in a seal groove formed around the circumference of the annular wall 182 and sealingly engages the annular wall 182 and the inner surface of the pilot bore 80 in the hub mount 62 of the end cap 32. An annular shoulder 214 is formed on the hub housing 170 that separates the first wheel bearing bore 192 and the second wheel bearing bore 200 from each other along the output axis 82.

[0042] The hub 172 may include a hub member 230 and a hub flange 232. The hub member 230 is a shaft on which a first bearing mounting surface 240, a second bearing mounting surface 242, and an outer hub seal surface 244 are formed. The hub member 230 is configured to drivingly engage with the driven gear 112 and thus may be configured to be directly coupled to the driven gear 112. For example, the driven gear 112 may include an internal spline bore, and the hub member 230 may include an external spline section (not shown) that is matingly received by the internal spline bore to couple the hub member 230 to the driven gear 112 for co-rotation. However, in the example provided, internal spline bores 250 and 252 are formed in both the driven gear 112 and the hub member 230, and the hub assembly 26 includes a short shaft 254 having external spline sections 256 and 258 that respectively engage the internal spline bores 250, 252 to rotatably couple the hub member 230 of the hub 172 to the driven gear 112 such that the hub 172 can rotate about the output axis 82. The hub flange 232 may be fixedly coupled to the hub member 230 (e.g., integrally and monolithically formed with the hub member 230) and may extend radially outward from the hub member 230. The hub flange 232 may define a wheel mounting surface 260 configured to abut the inner side of a wheel (not shown). In the example shown, a plurality of studs 262 are fitted through stud holes 264 in the hub flange 232 and are fixedly coupled to the hub flange 232. Lug nuts (not shown) may be threadedly engaged with the studs 262 to secure the wheel to the hub flange 232. Alternatively, the studs 262 may be omitted, and threaded holes (not shown) may replace the stud holes 264. In this alternative configuration, hub bolts (not shown) may be screwed into the threaded holes to secure the wheel to the hub flange 232. Each tapered roller bearing 174 is disposed on a respective one of the first bearing mounting surface 240 and the second bearing mounting surface 242 and is respectively received in a respective one of the first wheel bearing bore 192 and the second wheel bearing bore 299 to rotatably and axially support the hub member 230 relative to the hub housing 170. If desired, any desired technique may be used to preload the tapered roller bearings 174. In the example provided, a nut 268 is screwed onto a threaded section 270 on the hub member 230 and is tightened against the inner bearing race of the tapered roller bearing 174 disposed in the annular wall 182.

[0043] The outer hub seal 176 can be received in the outer hub seal bore 194 and fixedly and sealingly coupled to the body portion 180 of the hub housing 170. The outer hub seal 176 can be disposed at any desired location, but in the example provided, it is disposed along the output axis 82 between the hub flange 232 and the tapered roller bearing 174. The outer hub seal 176 can sealingly engage the outer hub seal surface 244 on the hub member 230. In the example shown, the outer hub seal 176 includes a lip member that contacts and sealingly engages the outer hub seal surface 244. Optionally, the hub 172 can include a slinger 280 that is disposed outside the outer hub seal 176 to protect the outer hub seal 176 from dirt and debris. The slinger 280 can have a tubular slinger hub 282 and a slinger flange 284, the tubular slinger hub 282 being received on and fixedly coupled to the hub member 230, and the slinger flange 284 extending radially outward from the slinger hub 282. The slinger flange 284 can contact the annular dust lip on the outer hub seal 176. Alternatively, the slinger flange 284 can be axially spaced from the outer hub seal 176.

[0044] Return to Figure 1 and Figure 2 , the center tube assembly 14 includes a center tube 300 that is received in the housing assemblies 20 of the drive units 12a, 12b and spans between and is fixedly coupled to the housing assemblies 20 of the drive units 12a, 12b. In this regard, each of the opposite axial ends of the center tube 300 is received in a tube bore 48 of a respective one of the tube mounts 38 and is fixedly coupled to an associated one of the housing members 30 such that the center tube 300 is coaxially disposed about the output axis 82. In the example provided, the center tube 300 is press fit into each tube bore 48 and a plug weld (not specifically shown) is formed in each weld plug hole 50 (i.e., by welding a weld plug (not shown) to the center tube 300) to inhibit axial and rotational movement of the center tube 300 relative to the tubular collar 46.

[0045] Refer to Figures 1 to 3, the central tube assembly 14 may include various other components that may be required to couple the electric beam axle 10 to a vehicle's suspension (not shown). In the illustrated example, a pair of brackets 320 are fixedly coupled (e.g., welded) to the central tube 300 and are used to mount the ends of corresponding upper control arms (not shown) to the electric beam axle 10. It will be understood that mounts for various other vehicle suspension and brake system components may be integrated into the electric drive axle 10. For example, leaf spring mounts (not shown) may be fixedly coupled to the central tube 300 (e.g., welded to or integrally formed with the central tube 300). In the provided example, the electric beam axle 10 includes a pair of spring seats 318, a pair of upper link mounts 320, a pair of lower link mounts 322, a pair of shock mounts 324, and a pair of caliper mounts 326.

[0046] Reference Figure 1 and Figure 4 , each spring seat 318 may be fixedly coupled to the central tube 300 or an associated one of the housing assemblies 20 in a desired manner. In the illustrated example, the spring seat 318 is a discrete component that mounts to a seat mount 350 integrally formed with the housing member 30. The spring seat mount 350 has a mounting boss 352 that defines a mounting surface 354 against which the spring seat 318 abuts. Threaded fasteners (not shown) may extend through the spring seat 318 and may threadedly engage threaded holes 356 formed in the mounting boss 352. However, it will be understood that the spring seat 318 itself may be integrally and monolithically formed with the housing member 30.

[0047] Reference Figure 1 , Figure 5 and Figure 6 , each upper link mount 320 and each lower link mount 322 are illustrated as being integrally and monolithically formed with an associated one of the housing members 30, but it will be understood that one or both of these components may be discrete components fixedly coupled to the central tube 300 or an associated one of the housing assemblies 20. In the provided example, the upper link mounts 320 and the lower link mounts 322 are formed as protrusions extending from the housing member 30 and have associated mounting holes 360 formed therethrough.

[0048] Reference Figure 3 and Figure 4 , the shock mounts 324 may be fixedly coupled to the housing assembly 20 or the central tube 300, but in the provided example, each shock mount 324 includes a pair of shock mount bosses 370 that are integrally and monolithically formed with the housing member 30. Each shock mount boss 370 includes a mounting surface 372 and a threaded hole 374 formed through the mounting surface 372.

[0049] Reference Figure 3 andFigure 8 Each caliper mount 326 is integrally and monolithically formed with an associated end cap 32 and includes a caliper mounting surface 380 in which a pair of threaded caliper bolt holes 382 are formed.

[0050] Reference Figure 17 FIG. schematically illustrates a second electric beam axle 10'. In this example, the electric beam axle 10' is generally similar to the electric beam axle 10 of Figure 1 except that the electric beam axle 10' is configured to selectively drivingly couple the motors of two drive units 12a', 12b' to two wheel hubs 172. The center tube 300 is positioned relative to the drive units 12a', 12b' such that the axis of rotation of the rotating element of the transmission 24 is disposed within the center tube 300. For example, the center tube 300 may be positioned relative to the drive units 12a', 12b' such that the axis of rotation of the output of the transmission 24 (i.e., the driven gear 112 in the illustrated example) is disposed within the center tube 300. The first stub shaft 400 may be coupled to rotate with the driven gear 112 of the drive unit 12a' and may extend through the center tube 300 into the housing member 30' of the drive unit 12b'. The second stub shaft 402 may be coupled to rotate with the driven gear 112 of the drive unit 12b' and is capable of extending toward the first stub shaft 400. Any type of coupling may be employed to selectively couple the first stub shaft 400 and the second stub shaft 402 to rotate with each other. In the example provided, a jaw clutch 410 is used to selectively couple the first stub shaft 400 and the second stub shaft 402 to each other. The jaw clutch 410 may include a first jaw member 412 rotatably coupled to the first stub shaft 400 and a second jaw member 414 rotatably coupled to the second stub shaft 402. One of the first jaw member 412 and the second jaw member 414 is axially movable along the axis of rotation of the driven member 112, the first stub shaft 400, and the second stub shaft 402 (i.e., the output axis 82 in the example provided) between a first position and a second position. In the first position, the first jaw member 412 and the second jaw member 414 are rotationally disengaged from each other, and in the second position, the first jaw member 412 and the second jaw member 414 are interconnected to rotate together about the output axis 82. Any type of actuator (not shown) may be employed to cause translation of the axially movable one of the first jaw member 412 and the second jaw member 414.

[0051] This configuration of the method is advantageous, for example, when one of the wheels driven by the electric beam axle 10' slips. In this case, the coupling (i.e., the jaw clutch 410 in the provided example) can be operated to rotatably couple the first stub shaft 400 and the second stub shaft 402, thereby rotatably coupling the driven gear 112 and the wheel hub 172 such that all rotational power (i.e., the rotational power provided by the two motors 90) is substantially applied to the non-slip drive wheel (when the opposite wheel slips).

[0052] For purposes of illustration and description, the foregoing description of the embodiments has been provided. It is not intended to be exhaustive or to limit the disclosure. The various elements or features of a particular embodiment are generally not limited to that particular embodiment, but are interchangeable where applicable and can also be used in the selected embodiment, even if not specifically shown or described. It can also be varied in many ways. These variations should not be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

Claims

1. An electric beam axle (10, 10'), comprising: A center tube (300) having opposite axial ends; the center tube (300) is coaxially arranged about an output axis (82); And A pair of drive units (12a, 12b; 12a', 12b'), each drive unit (12a, 12b; 12a', 12b') having a housing assembly (20), a motor assembly (22), a wheel hub assembly (26) and a transmission (24), the housing assembly (20) having a tube mount (38) and defining a cavity (34), the tube mount (38) defining a tube bore (48), the center tube (300) being received in the tube bore (48) and fixedly coupled to the tube mount (38), the motor assembly (22) having a motor (90), the motor (90) having a motor output shaft (94) rotatable about a motor axis (130), the motor assembly (22) being coupled to the housing assembly (20), the motor output shaft (94) extending into the cavity (34) in the housing assembly (20), the wheel hub assembly (26) being fixedly coupled to the housing assembly (20) and having a wheel hub (172) rotatable about the output axis (82), the transmission (24) drivingly connecting the motor output shaft (94) to the wheel hub (172) to transmit rotational power between the motor (90) and the wheel hub (172); Wherein the output axis (82) is offset from the motor axis (130).

2. The electric beam axle (10, 10') according to claim 1, wherein the housing assembly (20) includes a housing member (30; 30') and an end cap (32), the housing member (30; 30') and the end cap (32) being joined to each other in a plane perpendicular to the output axis (82), wherein the housing member (30; 30') includes a motor mounting flange (54), the motor (90) being mounted to the motor mounting flange (54), and wherein the end cap (32) has a hole (80) in which the wheel hub assembly (26) is mounted.

3. The electric beam axle (10, 10') according to claim 1, wherein the wheel hub assembly (26) further includes a wheel hub mount (62) and a stub shaft (254), wherein the wheel hub mount (62) is mounted to the housing assembly (20), and wherein the stub shaft (254) rotatably couples the output gear (112) of the transmission (24) and the wheel hub (172).

4. The electric beam axle (10, 10') according to claim 3, further comprising a pair of tapered roller bearings (160), each tapered roller bearing (160) being mounted at an associated axial end of the output gear (112) and supporting the output gear (112) for rotation about the output axis (82) relative to the housing assembly (20).

5. The electric beam axle (10, 10') according to claim 3, wherein the wheel hub (172) is supported to rotate relative to the wheel hub mount (62) about the output axis (82) on a pair of tapered roller bearings (174).

6. The electric beam axle (10, 10') according to claim 3, wherein the wheel hub (172) includes a wheel hub flange (232), and wherein the wheel hub assembly (26) further includes an outer hub seal (176) disposed along the output axis (82) between the wheel hub flange (232) and the tapered roller bearing (174).

7. The electric beam axle (10, 10') according to claim 3, wherein the wheel hub assembly (26) includes a seal member (210) circumferentially disposed between the wheel hub mount (62) and the inner surface of the hole (80) in the end cap (32).

8. The electric beam axle according to claim 3, wherein the stub shaft (254) includes a first external spline section (256) and a second external spline section (258), the first external spline section (256) engaging a first internal spline section on the output gear (112), and the second external spline section (258) engaging a second internal spline section on the wheel hub (172).

9. The electric beam axle (10, 10') according to claim 1, wherein the transmission (24) includes an input gear (110) and a pair of compound gears (114), the input gear (110) being coupled to the motor output shaft (94) to rotate therewith, and each of the compound gears (114) having a first reduction gear (122) meshing with the input gear (110).

10. The electric beam axle (10, 10') according to claim 9, wherein the transmission (24) further includes an output gear (112), and wherein each of the compound gears (114) has a second reduction gear (124) coupled to rotate with the first reduction gear (122), and wherein each of the second reduction gears (124) meshes with the output gear (112).

11. The electric beam axle (10, 10') according to claim 1, wherein each of the drive units (12a, 12b; 12a', 12b') further includes an inverter (10, 10'0), wherein the motor (90) has a motor housing (92), and wherein the inverter (10, 10'0) is electrically coupled to the motor (90) and mounted to the motor housing (92).

12. The electric beam axle (10, 10') according to claim 1, wherein each of the drive units (12a, 12b; 12a', 12b') further comprises a heat exchanger (10, 10'2), wherein the electric machine has an electric machine housing (92), and wherein the heat exchanger (10, 10'2) is fluidly coupled to the electric machine (90) and mounted to the electric machine housing (92).

13. The electric beam axle (10') according to claim 1, further comprising a first stub shaft (400), a second stub shaft (402) and a coupling (410), wherein the transmission (24) of each of the drive units (12a', 12b') has an output gear (112), wherein the first stub shaft (400) is received in the central tube (300) and coupled to rotate with the output gear (112) of the first one of the drive units (12a', 12b'), wherein the second stub shaft (402) is coupled to rotate with the output gear (112) of the second one of the drive units (12a', 12b'), and wherein the coupling (410) is selectively operable to rotationally couple the first stub shaft (400) and the second stub shaft (402).

14. The electric beam axle (10') according to claim 13, wherein the coupling (410) is a clutch.

15. The electric beam axle (10') according to claim 14, wherein the clutch is a claw clutch.

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