Electric beam axle
The electric beam axle design addresses the issue of insufficient ground clearance by integrating a center tube and drive units with enhanced structural support and power transmission, ensuring improved clearance and functionality for vehicle components.
Patent Information
- Application Number
- JP2025514379
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-09-08
- Filing Date
- 2023-09-07
- Publication Date
- 2025-10-07
AI Technical Summary
Existing electric beam axles lack sufficient ground clearance, particularly around the carrier housing and differential assembly, necessitating an improvement for enhanced design.
An electric beam axle design featuring a center tube and paired drive units, each comprising a housing assembly, motor assembly, and wheel hub assembly, with a transmission connecting the motor output shaft to the wheel hub, and optional components like inverters and heat exchangers, supported by bearings and seals, to enhance structural integrity and clearance.
The design provides improved ground clearance and structural support, enabling efficient power transmission while accommodating additional vehicle components like suspension and braking systems.
Smart Images
Figure 2025533419000001_ABST
Abstract
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001]
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 404,654, filed September 8, 2022, the disclosure of which is incorporated by reference as if fully set forth in this specification. [Technical Field]
[0002]
[0002] The present disclosure relates to an electric beam axle. [Background technology]
[0003]
[0003] This section provides background information related to the present disclosure that is not necessarily prior art.
[0004]
[0004] International Patent Application No. PCT / US2022 / 019900 discloses various configurations for relatively heavy-duty electric beam axles. While this configuration is well suited for its intended purpose, it is noted that there are situations in which additional ground clearance is desirable, for example, in areas of the electric beam axle including the carrier housing and differential assembly. Therefore, there is a need in the art for improved electric beam axles. Summary of the Invention
[0005]
[0005] This section provides a general overview of the disclosure and is not a comprehensive disclosure of its entire scope or all of its features.
[0006]
[0006] In one form, the present disclosure provides an electric beam axle including a center tube and a pair of drive units. The center tube has opposing axial ends and is coaxially disposed about an output shaft. Each of the drive units includes 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 includes an electric motor having a motor output shaft rotatable about a motor axis. The motor assembly is coupled to the housing assembly. The motor output shaft extends within the cavity of the housing assembly. The wheel hub assembly is fixedly coupled to the housing assembly and includes a wheel hub rotatable about the output shaft. The transmission drivingly connects the motor output shaft to the wheel hub to transmit rotational power between the electric motor and the wheel hub. The output shaft is offset from the motor axis.
[0007]
[0007] In some examples, the housing assembly includes a housing member and an end cap joined to each other across a plane perpendicular to the output shaft, the housing member including a motor mount flange to which the electric motor is mounted, and the end cap having a bore to which the wheel hub assembly is mounted.
[0008]
[0008] In another example, the wheel hub assembly further includes a wheel hub mount and a stub shaft. The wheel hub mount is attached to the housing assembly. The stub shaft rotatably couples an output gear of the transmission and the wheel hub. Optionally, the power beam axle can further include a pair of tapered roller bearings, each attached to an associated axial end of the output gear and supporting the output gear for rotation about the output shaft relative to the housing assembly. Also optionally, the wheel hub is supported on the pair of tapered roller bearings for rotation about the output shaft relative to the wheel hub mount. As another option, the wheel hub includes a wheel hub flange, and the wheel hub assembly further includes an outer hub seal disposed along the output shaft between the wheel hub flange and the tapered roller bearing. As yet another option, the wheel hub assembly includes a sealing member circumferentially disposed between the wheel hub mount and an inner surface of the bore of the end cap. As a further option, the stub shaft includes a first external spline segment that engages a first internal spline segment on the output gear and a second external spline segment that engages a second internal spline segment on the wheel hub.
[0009] In another example, the transmission includes an input gear coupled to the motor output shaft for rotation therewith and a pair of compound gears, each of the compound gears having a first reduction gear meshingly engaged with the input gear. Optionally, the transmission further includes an output gear, each of the compound gears having a second reduction gear coupled to rotate therewith and each of the second reduction gears meshingly engaged with the output gear.
[0010]
[0010] In yet another example, each of the electric motors has a motor housing, and each of the drive units further includes an inverter electrically coupled to the electric motor and mounted to the motor housing.
[0011]
[0011] In yet another example, each of the electric motors has a motor housing, and each of the drive units further includes a heat exchanger fluidly coupled to the electric motor and attached to the motor housing.
[0012] In a further example, the transmission of each of the drive units 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 central tube and coupled to rotate with the output gear of a first one of the drive units. The second stub shaft is coupled to rotate with the output gear of a second one of the drive units, and the coupling is selectively operable to rotatably couple the first and second stub shafts. Optionally, the coupling is a clutch, such as a dog clutch.
[0013]
[0013] Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
[0014]
[0014] The drawings described in this specification are intended only to illustrate selected embodiments rather than all possible implementation forms and are not intended to limit the scope of the present disclosure. [Brief explanation of the drawings]
[0015] [Figure 1]
[0015] FIG. 1 is a perspective view of an exemplary electric beam axle constructed in accordance with the teachings of the present disclosure. [Figure 2]
[0016] FIG. 2 is an exploded perspective view of a portion of the powered beam axle of FIG. 1 illustrating the drive unit and a portion of the center tube assembly in greater detail. [Figure 3] FIG. 2 is an exploded perspective view of a portion of the powered beam axle of FIG. 1 illustrating the drive unit and a portion of the center tube assembly in greater detail. [Figure 4]
[0017] FIG. 2 is a perspective view of a portion of the electric beam axle of FIG. 1 illustrating the housing member of one drive unit. [Figure 5] FIG. 2 is a perspective view of a portion of the electric beam axle of FIG. 1 illustrating the housing member of one drive unit. [Figure 6]
[0018] FIG. 2 is a side elevational view of the housing member. [Figure 7]
[0019] FIG. 7 is a cross-sectional view taken along line 7-7 of FIG. 6. [Figure 8]
[0020] FIG. 2 is a perspective view of a portion of the electric beam axle of FIG. 1 illustrating the end cap of one drive unit. [Figure 9] FIG. 2 is a perspective view of a portion of the electric beam axle of FIG. 1 illustrating the end cap of one drive unit. [Figure 10] FIG. 2 is a perspective view of a portion of the electric beam axle of FIG. 1 illustrating the end cap of one drive unit. [Figure 11]
[0021] FIG. 1 is a side elevation view of the end cap. [Figure 12]
[0022] FIG. 2 is a perspective view of a portion of the electric beam axle of FIG. 1 illustrating the motor assembly and transmission of one drive unit. [Figure 13]
[0023] FIG. 2 is a cross-sectional view taken along line 13-13 in FIG. 1. [Figure 14]
[0024] FIG. 2 is a perspective view of a portion of the electric beam axle of FIG. 1 illustrating the motor assembly, transmission, and wheel hub assembly of one drive unit. [Figure 15]
[0025] FIG. 2 is a cross-sectional view taken along line 15-15 of FIG. 1. [Figure 16]
[0026] FIG. 16 is a cross-sectional view taken along line 16-16 of FIG. [Figure 17]
[0027] FIG. 1 is a schematic diagram of a second exemplary powered beam axle constructed in accordance with the teachings of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION
[0016]
[0028] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.
[0017]
[0029] 1 of the drawings, an exemplary powered beam axle constructed in accordance with the teachings of the present disclosure is indicated generally by the reference numeral 10. The powered beam axle 10 can include a pair of drive units 12a, 12b and a center tube assembly 14.
[0018]
[0030] Because drive units 12a, 12b are generally similar, the description of drive unit 12a will suffice for drive unit 12b. Drive unit 12a may include a housing assembly 20, a motor assembly 22, a transmission 24, and a wheel hub assembly 26.
[0019]
[0031] 2 and 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.
[0020]
[0032] 4-7 , the housing member 30 may define a gear box 36, a tube mount 38, and a motor mount 40. The gear box 36 may open at an outer end or side of the housing member 30 and may define a first flange member 44 that 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 that defines a tube bore 48 that opens at an inner end of the housing member 30. Optionally, a plurality of weld slug openings 50 may be formed radially through the tubular collar 46 and may intersect with the tube bore 48. The weld slug openings 50 may be spaced around the circumference of the tubular collar 46. The tube bore 48 may be a blind bore or may optionally intersect with a portion of the cavity 34 defined by the housing member 30. The motor mount 40 defines a motor mount flange 54 and a motor output shaft bore 56 that intersects with the portion of the cavity 34 formed by the housing member 30. The motor mount flange 54 faces away from the open end of the gearbox 36.
[0021]
[0033] 8-11 , the end cap 32 may include a cover portion 60 and a wheel hub mount 62. The cover portion 60 may include a second flange member 66 configured to cooperate with the first flange member 44 ( FIG. 5 ) to close the open end of the gearbox 36 ( FIG. 5 ). In the example provided, a plurality of threaded fasteners 68 are received in holes 70 in the second flange member 66 and threadably engage threaded holes 72 ( FIG. 5 ) formed in the first flange member 44 ( FIG. 5 ). The wheel hub mount 62 may define a pilot bore 80 concentrically disposed about the output shaft 82 and a first end wall 84 perpendicular to the output shaft 82.
[0022]
[0034] 2 and 3, gaskets or seals (not specifically shown) may be placed where desired between the housing member 30 and the end cap 32 (e.g., between the first flange member 44 and the second flange member 66) to help seal the joint between the housing member 30 and the end cap 32. In the example provided, the housing member 30 and the end cap 32 are joined together across a plane perpendicular to the output shaft 82.
[0023]
[0035] 12 and 13 , the motor assembly 22 includes an electric motor 90 having a motor housing 92 and a motor output shaft 94. The motor housing 92 is attached to the motor mount flange 54 such that the motor output shaft 94 extends through the motor output shaft bore 56 into the portion of the cavity 34 defined by the gearbox 36. Optionally, the electric motor assembly 22 may 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 supply of power to the electric motor 90. The inverter 100 may be coupled to or attached to the motor housing 92 and may be electrically coupled to the electric motor 90. The heat exchanger 102 may be coupled to or attached to the motor housing 92 and may be used to cool a fluid that may circulate through the electric motor 90 and / or the transmission 24 to cool and / or lubricate the electric motor 90 and / or the transmission 24. A fluid pump 104 may be coupled to the motor housing 92 or housing assembly 20 and may provide a source of pressurized fluid that may be used to cool and / or lubricate the electric motor 90 and / or transmission 24, and optionally to cool the inverter 100. A filter mount may be coupled to the motor housing 92 and may be in fluid communication with the fluid pump 104. The filter mount may receive a fluid filter (not shown) that may be used to filter the fluid circulated through the drive unit 12a by the fluid pump 104. In the example provided, various galleries (specifically not shown) coupling the fluid pump 104, filter mount, and electric motor 90 may be integrally formed with the motor housing 92 and / or may be formed as separate components (i.e., tubes, hoses) that are coupled to the motor housing 92.
[0024]
[0036] 14 and 15 , the transmission 24 may 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 may include any number of reduction stages and may be configured as a single-speed transmission or a multi-speed transmission. The transmission 24 may include a drive gear 110, a driven gear 112, and gears such as a pair of compound gears 114 that transmit rotational power between the drive gear 110 and the driven gear 112. In the particular example provided, the transmission 24 is configured in the manner described in commonly assigned U.S. Pat. No. 1,129,534. In summary, the drive gear 110 is the input gear of the transmission 24 and is coupled to the motor output shaft 94 for rotation therewith, and the driven gear 112 is the output gear of the transmission 24 and is rotatable about the output shaft 82. Each of the compound gears 114 may include a shaft member 120, a first reduction gear 122 fixedly coupled to the shaft member 120 and in meshing engagement with the drive gear 110, and a second reduction gear 124 fixedly coupled to the shaft member 120 and in meshing engagement with the driven gear 112. Each of the shaft members 120 is rotatable about an intermediate axis 128 that is parallel to and offset from both the output shaft 82 and a motor axis 130 about which the motor output shaft 94 rotates. In the example provided, the motor axis 130 is coincident and offset from the output shaft 82.
[0025]
[0037] 16 , each of the shaft members 120 may be supported by an appropriate bearing. In the example provided, a roller bearing 140 is received in a first bearing bore 142 formed in the motor mount flange 54 and attached to a first axial end of a corresponding one of the shaft members 120, and a ball bearing 144 is received in a second bearing bore 146 formed in the cover portion 60 of the end cap 32 and attached to an opposite second axial end of a corresponding one of the shaft members 120. In the example shown, the ball bearing 144 is attached to the second axial end of the shaft member 120 such that an inner bearing race of the ball bearing 144 abuts a shoulder formed in the shaft member 120, a thrust washer or spacer is received over the second axial end of the shaft member 120 and abuts a side of the inner bearing race opposite the shaft member shoulder, 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 a second bearing bore 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 that is concentric with the second bearing bore 146. The housing member 30 may be attached to the end cap 32 to position the first axial end of the shaft member 120 within the first bearing bore 142. The roller bearing 140 may be attached to the first axial end of the shaft member 120 and received within the first bearing bore 142. The electric motor 90 may then be attached to the motor mount flange 54.
[0026]
[0038] It will be appreciated that other bearing configurations may be used in place of the roller and ball bearing combination illustrated in the accompanying drawings and described herein. For example, each shaft member 120 may be supported on its opposite axial ends by tapered roller bearings (not shown).
[0027]
[0039] The driven gear 112 may be supported for rotation by a pair of bearings, such as a pair of tapered roller bearings 160. A first one of the tapered roller bearings 160 may be received in a third bearing bore 162 formed in the wall of the gearbox 36, and a second one 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.
[0028]
[0040] The wheel hub assembly 26 may include a wheel hub housing 170, a wheel hub 172, a pair of tapered roller bearings 174, and an outer hub seal 176. The wheel hub housing 170 may include 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 the first end wall 84 of the wheel hub mount 62 formed on the end cap 32. The first wheel bearing bore 192 may be defined by a counterbore of a first diameter, and the outer hub seal bore 194 may be defined by a counterbore of a second, larger 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 within the pilot bore 80 of the wheel hub mount 62 of the end cap 32 to align the axes of the first wheel bearing bore 192 and the second wheel bearing bore 200 with the output shaft 82. A gasket or seal may be used to seal the interface between the end cap 32 and the wheel hub housing 170. A 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 within a seal groove formed around the circumference of the annular wall 182 and sealingly engages both the annular wall 182 and the inner surface of the pilot bore 80 of the wheel hub mount 62 of the end cap 32. An annular shoulder 214 is formed on the wheel hub housing 170 and separates the first wheel bearing bore 192 and the second wheel bearing bore 200 from one another along the output shaft 82.
[0029]
[0041] The wheel hub 172 may include a hub member 230 and a wheel hub flange 232. The hub member 230 is a shaft having a first bearing mount surface 240, a second bearing mount surface 242, and an outer hub sealing surface 244 formed thereon. The hub member 230 is configured to drivingly engage the driven gear 112 and thus may be configured to directly couple to the driven gear 112. For example, the driven gear 112 may include internal splined openings and the hub member 230 may include external splined segments (not shown) matingly received by the internal splined openings, coupling the hub member 230 to the driven gear 112 for co-rotation. However, in the example provided, internal splined openings 250 and 252 are formed in both the driven gear 112 and the hub member 230, respectively, and the wheel hub assembly 26 includes a stub shaft 254 having external splined segments 256 and 258 that engage the internal splined openings 250 and 252, respectively, rotatably coupling the hub member 230 of the wheel hub 172 to the driven gear 112 such that the wheel hub 172 is rotatable about the output shaft 82. A wheel hub flange 232 may be fixedly coupled to the hub member 230 (e.g., unitarily and integrally formed with the hub member 230) and may extend radially outward from the hub member 230. The wheel 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 received in stud holes 264 in the wheel hub flange 232 and fixedly coupled to the wheel hub flange 232. Lug nuts (not shown) may threadably engage the studs 262 to secure the wheel to the wheel hub flange 232. Alternatively, the studs 262 may be omitted, and threaded openings (not shown) may substitute for the stud holes 264. In this alternative configuration, wheel hub bolts (not shown) may be threaded into the threaded openings to secure the wheel to the wheel hub flange 232.Each of the tapered roller bearings 174 is disposed on a corresponding one of the first and second bearing mount surfaces 240 and 242 and is received in a corresponding one of the first and second wheel bearing bores 192 and 200, respectively, to rotatably and axially support the hub member 230 relative to the wheel hub housing 170. The tapered roller bearings 174 may be preloaded using any desired technique, if desired. In the example provided, a nut 268 is threaded onto a threaded segment 270 of the hub member 230 and tightened against an inner bearing race of the tapered roller bearing 174 disposed in the annular wall 182.
[0030]
[0042] The outer hub seal 176 may be received within the outer hub seal bore 194 and fixedly and sealingly coupled to the body portion 180 of the wheel hub housing 170. The outer hub seal 176 may be positioned anywhere desired, but in the example provided, is positioned along the output shaft 82 between the wheel hub flange 232 and the tapered roller bearing 174. The outer hub seal 176 may sealingly engage an 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 wheel hub 172 may include a slinger 280 positioned on an outer side of the outer hub seal 176 to protect the outer hub seal 176 from dirt and debris. The slinger 280 may have a tubular slinger hub 282 received on and fixedly coupled to the hub member 230, and a slinger flange 284 extending radially outward from the slinger hub 282. The slinger flange 284 may contact an annular dust lip on the outer hub seal 176. Alternatively, the slinger flange 284 may be axially spaced from the outer hub seal 176.
[0031]
[0043] 1 and 2 , the central tube assembly 14 includes a central tube 300 that is received within, spans between, and fixedly couples the housing assemblies 20 of the drive units 12 a, 12 b. In this regard, each of the opposing axial ends of the central tube 300 is received within a tube bore 48 of a corresponding one of the tube mounts 38 and is fixedly coupled to an associated one of the housing members 30 such that the central tube 300 is coaxially disposed about the output shaft 82. In the example provided, the central tube 300 is press-fit into each of the tube bores 48, and a slug weld (not specifically shown) is formed in each of the weld slug openings 50 (i.e., by welding a weld slug (not shown) to the central tube 300) to prevent axial rotational movement of the central tube 300 relative to the tubular collar 46.
[0032]
[0044] 1-3 , the center tube assembly 14 can include various other components that may be necessary to couple the electric beam axle 10 to a vehicle suspension (not shown). In the illustrated example, a pair of brackets 320 are fixedly coupled (e.g., welded) to the center tube 300 and are used to attach the ends of respective upper control arms (not shown) to the electric beam axle 10. It will be appreciated that mounts for various other vehicle suspension and braking system components can be integrated into the electric beam axle 10. For example, leaf spring mounts (not shown) can be fixedly coupled (e.g., welded or integrally formed with) the center tube 300. In the example provided, 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.
[0033]
[0045] 1 and 4, each of the spring seats 318 may be fixedly coupled to the central tube 300 or an associated one of the housing assemblies 20 in any desired manner. In the illustrated example, the spring seats 318 are separate components mounted to a seat mount 350 that is unitarily and 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. A threaded fastener (not shown) may extend through the spring seat 318 and threadably engage a threaded opening 356 formed in the mounting boss 352. However, it will be understood that the spring seat 318 itself may be unitarily and integrally formed with the housing member 30.
[0034]
[0046] 1, 5, and 6, although each of upper link mounts 320 and each of lower link mounts 322 are illustrated as being unitarily and integrally formed with an associated one of housing members 30, it will be understood that one or both of these components may be separate components fixedly coupled to center tube 300 or an associated one of housing assemblies 20. In the example provided, upper link mount 320 and lower link mount 322 are formed as protrusions extending from housing member 30 and have associated mounting bores 360 formed therethrough.
[0035]
[0047] 3 and 4, shock mounts 324 may be fixedly coupled to housing assembly 20 or center tube 300, but in the example provided, each shock mount 324 includes a pair of shock mount bosses 370 unitarily and integrally formed with housing member 30. Each shock mount boss 370 includes a mounting surface 372 and a threaded hole 374 formed therethrough.
[0036]
[0048] 3 and 8, each caliper mount 326 is unitarily and integrally formed with an associated one of the end caps 32 and includes a caliper mounting surface 380 having a pair of threaded caliper bolt holes 382 formed therein.
[0037]
[0049] Referring to FIG. 17, a second electric beam axle 10′ is schematically illustrated. In this example, the electric beam axle 10′ is generally similar to the electric beam axle 10 of FIG. 1, except that the electric beam axle 10′ is configured to selectively drivingly couple the electric motors of both drive units 12a′, 12b′ to both wheel hubs 172. The central tube 300 is positioned relative to the drive units 12a′, 12b′ such that the rotational axes of the rotating elements of the transmission 24 are disposed within the central tube 300. For example, the central tube 300 may be positioned relative to the drive units 12a′, 12b′ such that the rotational axis of the output of the transmission 24 (i.e., the driven gear 112 in the illustrated example) is disposed within the central tube 300. A first stub shaft 400 may be coupled for rotation with the driven gear 112 of the drive unit 12a′ and may extend through the central tube 300 into the housing member 30′ of the drive unit 12b′. A second stub shaft 402 may be coupled for rotation with the driven gear 112 of the drive unit 12b′ and may extend toward the first stub shaft 400. Any type of coupling may be used to selectively couple the first stub shaft 400 and the second stub shaft 402 for rotation with one another. In the example provided, a dog clutch 410 is used to selectively couple the first stub shaft 400 and the second stub shaft 402 with one another. The dog clutch 410 may include a first dog member 412 rotatably coupled to the first stub shaft 400 and a second dog member 414 rotatably coupled to the second stub shaft 402. One of the first dog member 412 and the second dog member 414 is movable along the rotational axis of the driven member 112, the first stub shaft 400, and the second stub shaft 402 (i.e., the output shaft 82 in the example provided) between a first position in which the first dog member 412 and the second dog member 414 are rotationally engaged and disengaged from one another, and a second position in which the first dog member 412 and the second dog member 414 are coupled to one another so as to co-rotate about the output shaft 82.Any type of actuator (not shown) may be used to translate the axially movable one of the first dog member 412 and the second dog member 414 .
[0038]
[0050] This style of configuration is advantageous, for example, when one of the wheels driven by powered beam axle 10′ is slipping. In this situation, the coupling (i.e., dog clutch 410 in the example provided) is operable to rotatably couple first stub shaft 400 and second stub shaft 402, thereby rotatably coupling driven gear 112 and wheel hub 172, so that essentially all of the rotational power (i.e., the rotational power provided by both electric motors 90) is applied to the non-slip drive wheel (when the opposite wheel is slipping).
[0039]
[0051] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the present disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, may be interchangeable and used in selected embodiments even if not specifically shown or described. The same may be modified in many ways. Such variations should not be considered a departure from the present disclosure, and all such modifications are intended to be included within the scope of the present disclosure.
Claims
1. a central tube (300) having opposite axial ends, wherein said central tube (300) is coaxially disposed about an output shaft (82); A pair of drive units (12a, 12b; 12b', 12b'), 1. An electric beam axle (10, 10') comprising: each of the drive units (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) has a tube mount (38) and defines a cavity (34); the tube mount (38) defines a tube bore (48); the central tube (300) is received within the tube bore (48) and is fixedly coupled to the tube mount (38); and the motor assembly (22) has a motor output shaft (130) rotatable about a motor axis (130). an electric motor (90) having an output shaft (94), the motor assembly (22) coupled to the housing assembly (20), the motor output shaft (94) extending within the cavity (34) of the housing assembly (20); the wheel hub assembly (26) fixedly coupled to the housing assembly (20) and having a wheel hub (172) rotatable about the output shaft (82); the transmission (24) drivingly connects the motor output shaft (94) to the wheel hub (172) for transmitting rotational power between the electric motor (90) and the wheel hub (172); The output shaft (82) is offset from the motor shaft (130).
2. 2. The electric beam axle (10, 10') of claim 1, wherein the housing assembly (20) includes a housing member (30; 30') and an end cap (32) joined to each other across a plane perpendicular to the output shaft (82), the housing member (30; 30') including a motor mount flange (54) to which the electric motor (90) is attached, and the end cap (32) has a bore (80) to which the wheel hub assembly (26) is attached.
3. 2. The electric beam axle (10, 10') of claim 1, wherein the wheel hub assembly (26) further includes a wheel hub mount (62) and a stub shaft (254), the wheel hub mount (62) attached to the housing assembly (20), and the stub shaft (254) rotatably coupling an output gear (112) of the transmission (24) and the wheel hub (172).
4. 4. The electric beam axle (10, 10') of claim 3, further comprising a pair of tapered roller bearings (160), each attached to an associated axial end of the output gear (112) and supporting the output gear (112) for rotation about the output shaft (82) relative to the housing assembly (20).
5. 4. The electric beam axle (10, 10') of claim 3, wherein the wheel hub (172) is supported on a pair of tapered roller bearings (174) for rotation about the output shaft (82) relative to the wheel hub mount (62).
6. 4. The electric beam axle (10, 10') of claim 3, wherein the wheel hub (172) includes a wheel hub flange (232), and the wheel hub assembly (26) further includes an outer hub seal (176) disposed along the output shaft (82) between the wheel hub flange (232) and the tapered roller bearing (174).
7. 4. The electric beam axle (10, 10') of claim 3, wherein the wheel hub assembly (26) includes a seal member (210) circumferentially disposed between the wheel hub mount (62) and an inner surface of the bore (80) of the end cap (32).
8. 4. The electric beam axle (10, 10') of claim 3, wherein the stub shaft (254) includes a first external spline segment (256) that engages a first internal spline segment on the output gear (112) and a second external spline segment (258) that engages a second internal spline segment on the wheel hub (172).
9. 2. The electric beam axle (10, 10') of claim 1, wherein the transmission (24) includes an input gear (110) coupled to the motor output shaft (94) for rotation therewith, and a pair of compound gears (114), each of the compound gears (114) having a first reduction gear (122) in meshing engagement with the input gear (110).
10. 10. The electric beam axle (10, 10') of claim 9, wherein the transmission (24) further includes an output gear (112), each of the compound gears (114) having a second reduction gear (124) coupled to rotate with the first reduction gear (122), each of the second reduction gears (124) in meshing engagement with the output gear (112).
11. 2. The electric beam axle (10, 10') of claim 1, wherein each of the drive units (12a, 12b; 12a', 12b') further includes an inverter (100), the electric motor (90) has a motor housing (92), and the inverter (100) is electrically coupled to the electric motor (90) and attached to the motor housing (92).
12. 2. The electric beam axle (10, 10') of claim 1, wherein each of the drive units (12a, 12b; 12a', 12b') further includes a heat exchanger (102), the electric motor having a motor housing (92), and the heat exchanger (102) is fluidly coupled to the electric motor (90) and attached to the motor housing (92).
13. 2. The electric beam axle of claim 1, further comprising: a first stub shaft, a second stub shaft, and a coupling, wherein the transmission of each of the drive units has an output gear, the first stub shaft is received in the central tube and coupled to rotate with the output gear of a first one of the drive units, the second stub shaft is coupled to rotate with the output gear of a second one of the drive units, and the coupling is selectively operable to rotatably couple the first stub shaft and the second stub shaft.
14. The electric beam axle (10') of claim 13, wherein the coupling (410) is a clutch.
15. 15. The electric beam axle (10') of claim 14, wherein the clutch is a dog clutch.