Compact drivetrain and powertrain assembly for electric vehicle

Abstract

A drivetrain assembly for an electric movable machine, the drivetrain assembly including a gearbox including an input end, an output end, and an output carrier arranged at the output end, a plate, including a first surface connected to the gearbox, a protrusion forming an axial surface, and a first radially inward facing surface, wherein a first bearing is arranged radially between the first radially inward facing surface and the output carrier, an output shaft non-rotatably connected to the output carrier, and a bracket connected to the plate and including a second radially inward facing surface, wherein a second bearing is arranged radially between the second radially inward facing surface and the output shaft.

Description

COMPACT DRIVETRAIN AND POWERTRAIN ASSEMBLY FOR ELECTRIC VEHICLECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit under Articles 4 and 8 of the Stockholm Act of the Paris Convention for the Protection of Industrial Property of U.S. Provisional Patent Application No. 63 / 557,832, filed on February 26, 2024, and U.S. Provisional Patent Application No. 63 / 556,324, filed on February 21, 2024, which applications are incorporated herein by reference in their entireties.TECHNICAL FIELD

[0002] The present disclosed subject matter relates generally to powertrains for vehicles, and more particularly, to a drivetrain and powertrain assembly for an electric vehicle.BACKGROUND ART

[0003] Movable machinery or machine, heavy equipment, heavy machinery, and / or earthmover refers to heavy-duty vehicles specially designed to execute construction tasks, most frequently involving earthwork operations or other large construction tasks. Some examples of movable machinery are bulldozers, agricultural tractors, excavators, cranes, backhoes, skid steers, and loaders. Movable machinery usually comprises five equipment systems: the implement, traction, structure, power train, and control / information. Movable machinery functions through the mechanical advantage of a simple machine, the ratio between input force applied and force exerted is multiplied, making tasks which could take hundreds of people and weeks of labor without heavy equipment far less intensive in nature. Some equipment uses hydraulic drives as a primary source of motion.

[0004] Internal combustion engines, namely diesel engines, are the dominant power source of movable machinery. As the desire for cleaner energy usage grows, there is a shift toward the use of electrically powered movable machines. However, current drivetrain and powertrain designs are too large for implementation of battery power sources in vehicles.BRIEF SUMMARY

[0005] With parenthetical reference to corresponding parts, portions or surfaces of the disclosed embodiment, merely for the purposes of illustration and not by way of limitation, the present disclosure provides a drivetrain assembly (32) for an electric movable machine (2), the drivetrain assembly (32) comprising a gearbox (70) including an input end (72), an output end(74), and an output carrier (80) arranged at the output end (74), a plate (90), including a first surface (92) connected to the gearbox (70), a protrusion (96) forming an axial surface (98), and a first radially inward facing surface (100), wherein a first bearing (104) is arranged radially between the first radially inward facing surface (100) and the output carrier (80), an output shaft (110) non- rotatably connected to the output carrier (80), and a bracket (130) connected to the plate (90) and comprising a second radially inward facing surface (144), wherein a second bearing (150) is arranged radially between the second radially inward facing surface (144) and the output shaft (HO).

[0006] In an exemplary embodiment, the bracket (130) may comprise a housing portion (132) that at least partially encloses the output shaft (100), and a flange portion (138) fixedly secured to the plate (90). In an exemplary embodiment, the housing portion (132) may comprise at least one window (140A, 140B, 140C, 140D) extending radially therethrough. In an exemplary embodiment, the drivetrain assembly (32) may further comprise a sprocket assembly (120) non- rotatably connected to the output shaft (110). In an exemplary embodiment, the sprocket assembly (120) may comprise a first sprocket (122), and a second sprocket (124) separated from the first sprocket (122) in an axial direction (AD2). In an exemplary embodiment, the drivetrain assembly (32) may further comprise a chain (8, 10) engaged with the sprocket assembly (120). In an exemplary embodiment, the gearbox (70) may comprise a cycloidal gearbox. In an exemplary embodiment, the gearbox (70) may comprise a planetary gearbox.

[0007] In an exemplary embodiment, the present disclosure provides a powertrain assembly (30) for an electric movable machine (2), the powertrain assembly (30) comprising a motor (50), and a drivetrain assembly (32), including a gearbox (70) comprising an input end (72) connected to the motor (50), an output end (74), and an output carrier (80) arranged at the output end (74), a plate (90), comprising a first surface (92) connected to the gearbox (72), a protrusion (96) forming an axial surface (98), and a first radially inward facing surface (100), wherein a first bearing (104) is arranged radially between the first radially inward facing surface (100) and the output carrier (80), an output shaft (110) non-rotatably connected to the output carrier (80), and a bracket element (130) connected to the plate (90) and comprising a second radially inward facing surface (144), wherein a second bearing (150) is arranged radially between the second radially inward facing surface (144) and the output shaft (110).

[0008] In an exemplary embodiment, the bracket element (130) may comprise a housing portion (132) that at least partially encloses the output shaft (110), and a flange portion (138) fixedly secured to the plate (90). In an exemplary embodiment, the housing portion (130) may comprise at least one window (140A, MOB, 140C, MOD) extending radially therethrough. In an exemplary embodiment, the at least one window (140A, MOB, 140C, MOD) may comprise a first window (140C) and a second window (140A) spaced apart in a circumferential direction from the first window (140C), and a chain (8) extends through the first window (140C) and the second window (140 A) and engages the output shaft (110).

[0009] In an exemplary embodiment, the powertrain assembly (30) may further comprise a sprocket assembly (120) non-rotatably connected to the output shaft (110). In an exemplary embodiment, the sprocket assembly (120) may comprise a first sprocket (122), and a second sprocket (124) separated from the first sprocket (122) in an axial direction (AD2). In an exemplary embodiment, the powertrain assembly (30) may further comprise a chain (8, 10) engaged with the sprocket assembly (120).

[0010] In an exemplary embodiment, the powertrain assembly (30) may further comprise a rotor brake (60) connected to the motor (50), the motor (50) being arranged axially between the rotor brake (60) and the gearbox (70). In an exemplary embodiment, the powertrain assembly (30) may further comprise a rotor brake (60) connected to the motor (50), the rotor brake (60) being arranged axially between the motor (50) and the gearbox (70). In an exemplary embodiment, the powertrain assembly (30) may further comprise comprising an encoder (62).

[0011] In an exemplary embodiment, the present disclosure provides an electric movable machine (2), comprising a chassis (20) including an inner wall (22) comprising a hole (26), and an outer wall (24) separated from the inner wall (22) in an axial direction (AD2), and a drivetrain assembly (32), including a gearbox (70) comprising an input end (72), an output end (74), and an output carrier (80) arranged at the output end (74), a plate (90) connected to the inner wall (22), comprising a first surface (92) connected to the gearbox (70), a protrusion (96) forming an axial surface (98), the protrusion (96) extending through the hole (26) in the axial direction (AD2), and a first radially inward facing surface (100), wherein a first bearing (104) is arranged radially between the first radially inward facing surface (100) and the output carrier (80), and an output shaft (110) non-rotatably connected to the output carrier (80).

[0012] In an exemplary embodiment, the electric movable machine (2) may further comprise a bracket element (130) connected to the plate (90) and comprising a second radially inward facing surface (144), wherein a second bearing (150) is arranged radially between the second radially inward facing surface (144) and the output shaft (110).

[0013] The following will describe embodiments of the present disclosure, but it should be appreciated that the present disclosure is not limited to the described embodiments and various modifications of the disclosure are possible without departing from the basic principles. The scope of the present disclosure is therefore to be determined solely by the appended claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Various embodiments are disclosed, by way of example only, with reference to the accompanying schematic drawings below in which corresponding reference symbols indicate corresponding parts.

[0015] FIG. l is a perspective view of an electric movable machine.

[0016] FIG. 2 is a top planar view of the electric movable machine shown in FIG. 1.

[0017] FIG. 3 is a top planar schematic view of a chassis.

[0018] FIG. 4 is a cross-sectional view of the chassis taken generally along line 4-4 in FIG.3.

[0019] FIG. 5 is a partial cross-sectional view of the electric movable machine taken generally along line 5-5 in FIG. 1.

[0020] FIG. 6 is a perspective view of a first embodiment of the powertrain assembly shown in FIG. 1.

[0021] FIG. 7 is a cross-sectional view of the powertrain assembly taken generally along line 7-7 in FIG. 6.

[0022] FIG. 8 is a partial cross-sectional view of the electric movable machine taken generally along line 5-5 in FIG. 1, showing the first embodiment of the powertrain assembly of FIG. 6.

[0023] FIG. 9 is a partial cross-sectional view of the electric movable machine taken generally along line 5-5 in FIG. 1, showing a second embodiment of the powertrain assembly.

[0024] FIG. 10 is a sectional view of a third embodiment of the powertrain assembly shown in FIG. 1.

[0025] FIG. 11 is a partial cross-sectional view of the electric movable machine taken generally along line 5-5 in FIG. 1, showing a fourth embodiment of the powertrain assembly.

[0026] FIG. 12 is a partial cross-sectional view of a fifth embodiment of the powertrain assembly shown in FIG. 1.

[0027] FIG. 13 is a partial cross-sectional view of the electric movable machine taken generally along line 13-13 in FIG. 2.DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] At the outset, it should be clearly understood that like reference numerals are intended to identify the same structural elements, portions, or surfaces consistently throughout the several drawing figures, as such elements, portions or surfaces may be further described or explained by the entire written specification, of which this detailed description is an integral part. Unless otherwise indicated, the drawings are intended to be read (e g., cross-hatching, arrangement of parts, proportion, degree, etc.) together with the specification, and are to be considered a portion of the entire written description of this invention. As used in the following description, the terms “horizontal,” “vertical,” “left,” “right,” “up” and “down,” as well as adjectival and adverbial derivatives thereof (e.g., “horizontally,” “rightwardly,” “upwardly,” etc.), simply refer to the orientation of the illustrated structure as the particular drawing figure faces the reader. Similarly, the terms “inwardly” and “outwardly” generally refer to the orientation of a surface relative to its axis of elongation, or axis of rotation, as appropriate.

[0029] Furthermore, it is understood that this disclosure is not limited to the particular methodology, materials, and modifications described and as such may, of course, vary. It is also understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to limit the scope of the claims.

[0030] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this disclosure pertains. It should be understood that any methods, devices, or materials similar or equivalent to those described herein can be used in the practice or testing of the example embodiments.

[0031] It should be appreciated that the term “substantially” is synonymous with terms such as “nearly,” “very nearly,” “about,” “approximately,” “around,” “bordering on,” “close to,” “essentially,” “in the neighborhood of,” “in the vicinity of,” etc., and such terms may be used interchangeably as appearing in the specification and claims. It should be appreciated that the term“proximate” is synonymous with terms such as “nearby,” “close,” “adjacent,” “neighboring,” “immediate,” “adjoining,” etc., and such terms may be used interchangeably as appearing in the specification and claims. The term “approximately” is intended to mean values within ten percent of the specified value.

[0032] Where used herein, the term “exemplary” is intended to mean “an example of,” “serving as an example,” or “illustrative,” and does not denote any preference or requirement with respect to a disclosed aspect or embodiment.

[0033] Moreover, as used herein, the phrases “comprises at least one of’ and “comprising at least one of’ in combination with a system or element is intended to mean that the system or element includes one or more of the elements listed after the phrase. For example, a device comprising at least one of: a first element; a second element; and a third element, is intended to be construed as any one of the following structural arrangements: a device comprising a first element; a device comprising a second element; a device comprising a third element; a device comprising a first element and a second element; a device comprising a first element and a third element; a device comprising a first element, a second element, and a third element; or a device comprising a second element and a third element. A similar interpretation is intended when the phrase “used in at least one of” is used herein.

[0034] By “non-rotatably connected” elements, it is meant that the elements are connected so that whenever one of the elements rotate, all the elements rotate, and relative rotation between the elements is not possible. Radial and / or axial movement of non-rotatably connected elements with respect to each other is possible, but not required. By “rotatably connected” elements, it is meant that the elements are rotatable with respect to each other, and whenever one element is displaced radially and / or axially, all the elements are displaced radially and / or axially.

[0035] Referring now to the figures, FIG. 1 is a perspective view of electric movable machine 2. FIG. 2 is a top planar view of electric movable machine 2. Electric movable machine 2 is a piece of heavy equipment comprising wheels or track 12, implement or work tool 14, chassis 20, and at least one powertrain assembly 30. In an exemplary embodiment, electric movable machine 2 further comprises at least one axle, for example axle 4 and axle 6, and / or battery 18. In an exemplary embodiment, electric movable machine 2 further comprises hydraulic equipment. In an exemplary embodiment, electric movable machine 2 is a skid steer.

[0036] Work tool 14 is connected to chassis 20 by one or more arms or booms 16. An operator is capable of controlling arms 16 and work tool 14 via various components such as joysticks, levers, pedals, and / or other controls and user interfaces, for example, in a cab of electric movable machine 2. Work tool 14 and arms 16 are moved via one or more actuators, for example, hydraulic actuators. It should be appreciated that, in an exemplary embodiment, electric movable machine 2 may comprise electric actuators in addition or alternative to hydraulic actuators.

[0037] Powertrain assembly 30 is connected to chassis 20. Chassis 20 comprises inner wall 22 and outer wall 24 spaced apart from inner wall 22, for example in axial direction AD2. Chassis 20 further comprises hole 26 with which powertrain assembly 30 and / or drivetrain assembly 32 is engaged, as will be described in greater detail below. In an exemplary embodiment, hole 26 is arranged in inner wall 22. Powertrain assembly 30 is connected to axle 4 via chain or strap or line 8. Powertrain assembly 30 is connected to axle 6 via chain or strap or line 10. In an exemplary embodiment, chain 8 and / or chain 10 are arranged in chassis 20, namely, axially between inner wall 22 and outer wall 24.

[0038] FIG. 3 is a top planar schematic view of chassis 20. FIG. 4 is a cross-sectional view of chassis 20 taken generally along line 4-4 in FIG. 3. In the exemplary embodiment shown, hole 26 is a through-hole that extends completely through inner wall 22, and opens toward a top or a bottom surface of chassis 20. In an exemplary embodiment, the slot openings (i.e., hole 26) can be correspondingly stiffened.

[0039] FIG. 5 is a partial cross-sectional view of electric movable machine 2 taken generally along line 5-5 in FIG. 1. In the exemplary embodiment shown, hole 26 is a through-bore enclosed by inner wall 22. That is, hole 26 does not open toward a side of inner wall 22 as shown in FIG. 4. Powertrain 30 is arranged at least partially within chassis 20. As shown, motor 40 may comprise one or more ports. For example, motor 40 may comprise one or more ports 56 for electrical and / or communication connection. Such ports 56 may comprise a signal port for, for example, to activate / deactivate rotor brake 60. Such ports 56 may also include standard power connectors (e.g., a lead connector, a neutral connector, and a ground connector). Motor 40 may further comprise ports 58 for fluid communication. For example, ports 58 may comprise one or more inlet ports and one or more outlet ports for circulating temperature regulating fluid (e.g., coolant) in powertrain 30 (e.g., motor 40).

[0040] FIG. 6 is a perspective view of a first embodiment of powertrain assembly 30. FIG. 7 is a cross-sectional view of powertrain assembly 30 taken generally along line 7-7 in FIG. 6. FIG. 8 is a partial cross-sectional view of electric movable machine 2 taken generally along line 5-5 in FIG. 1, showing the first embodiment of powertrain assembly 30. Powertrain assembly 30 generally comprises drivetrain assembly 32 and motor 40. In an exemplary embodiment, powertrain assembly 30 further comprises rotor brake 60.

[0041] Motor 40 generally includes motor housing 50 containing stator 54 and rotor 52 configured to rotate about axis X relative to stator 54 and motor housing 50. Motor 40 comprises input end 42 and output end 44. In an exemplary embodiment, motor 40 further comprises flange 46 at end 44. Flange 46 may include one or more through-holes 48 operatively arranged to facilitate connection of motor 40 to another component, for example, gearbox 70, plate 90, and / or chassis 20.

[0042] As shown, housing 50 is a generally hollow cylindrical member comprising left end 44 having an opening from which rotor 52 projects, an outer cylindrical casing, and right end 42 having a portion projecting into the interior of rotor shaft 56 of rotor 52. Stator 54 is fixedly supported in housing 50 between end 42 and end 44 of housing 50 such that stator 54 does not rotate relative to motor housing 50. Rotor 52 is rotationally supported in housing 50 by an annular bearing positioned radially between rotor shaft 56 and housing 50, namely, the projecting portion of end 42. In an exemplary embodiment, motor 40 comprises a high torque power dense motor (HTPDM) and / or a transverse flux motor, which provides for flux generation in both an axial direction (parallel to axis of rotation X) and a radial direction (perpendicular to axis of rotation X), a high torque output, and reduced volume.

[0043] Stator 54 is a generally cylindrical member elongated about axis X and having an inner space in which rotor 52 rotates about axis X relative to stator 54. Stator 54 is primarily formed from three sections that are stacked in the axial direction interior to housing 50 and sandwiched between end 42 and end 44 of housing 50. These individual stator pole sections may be glued, bolted, clamped, or otherwise fastened together in housing 50 to form stator 54.

[0044] As shown, each stator section generally comprises an outer cylindrical yoke or body portion, a stator pole section projecting radially inward from the outer body portion, and an inner coil. The inner coil comprises a plurality of conductive windings that may be selectively energizedvia leads as desired to magnetically interact with rotor 52 to exert a torque on and rotational movement of rotor 52 relative to stator 54.

[0045] In this embodiment, the pole section generally comprises a plurality of circumferentially spaced alternating permanent magnets and flux concentrators that extend radially in from and are supported by the outer cylindrical body portion. Each of the magnets extends axially along the longitudinal axis of the pole section and is positioned radially about the axis on the inner circumference of the body portion to thereby form magnetic poles. The magnets are permanently affixed around the inner circumference of the body portion. Each of the concentrators also extends axially along the longitudinal axis of the stator pole section and is positioned radially about the axis on the inner circumference of the body portion. The concentrators are permanently affixed around the inner circumference of the body portion between the magnets. Thus, the stator pole section includes a plurality of flux concentrators between a plurality of magnetic poles, with each of the flux concentrators and magnetic poles extending axially along the longitudinal axis and positioned radially about the axis such that each flux concentrator alternates with each magnetic pole on the inner circumference of the cylindrical outer body portion about the axis.

[0046] Each coil comprises electromagnetic windings that include at least one turn. The coils are each wound with copper, aluminum wires, ribbons, or any other material suitable for the intended purpose and understood by one of ordinary skill in the art. The coils may include a relatively square cross-section, or other embodiments may include an annular coil having a circular or oblong cross-section.

[0047] Rotor 52 is a generally cylindrical member elongated about axis of rotation X and generally includes shaft 56 having at the right end an annular retaining shoulder and having at the left end an annular end clamp. In this embodiment, four rotor disks or pole sections and three toroid sections are stacked in the axial direction on shaft 56 and sandwiched between the shaft retaining shoulder and shaft clamp. Moving right to left with reference to FIGS. 7-8, a first rotor pole section is stacked against the end clamp, a first toroid is stacked against the left annular face of the first rotor pole section, a second rotor pole section 32c is stacked against the right annular face of the first toroid, a second toroid is stacked against the left annular face of the second rotor pole section, a third rotor pole section is stacked against the left annular face of second toroid, a third toroid is stacked against the left annular face of third rotor pole section, a fourth rotor pole section is stacked against the left annular face of the third toroid, and the annular face of the retaining shoulder isstacked against the left annular face of the fourth rotor pole section. These individual rotor pole sections and rotor toroid sections may be glued, bolted, clamped, or otherwise fastened together and on shaft 56 between the retaining shoulder and end clamp to form rotor 52.

[0048] Each of the rotor pole sections are annular disk-shaped members formed of a plurality of radially extending pole pieces spaced circumferentially about the central axis and radially retained in a solid support plate. In some embodiments, each of radially extending pole pieces spaced circumferentially about central axis X are further radially supported by a retaining ring in the support plate.

[0049] Rotor brake 60 is connected to motor 40. In the embodiment shown in FIGS. 6-8, rotor brake 60 is connected to end 42 of motor 40. Thus, motor 40 is arranged axially between rotor brake 60 and gearbox 70. Rotor brake 60 is operatively arranged to, when activated, resist rotational displacement of rotor 52 to slow down the turning of wheels 12. In an exemplary embodiment, rotor brake 60 comprises a larger diameter but smaller axial length in order to reduce the overall length of powertrain 30. In an exemplary embodiment, rotor brake 60 comprises a friction based brake for static and dynamic braking. In an exemplary embodiment, brake 60 can be applied external to powertrain 30, and need not be connected directly to motor 40.

[0050] In an exemplary embodiment, motor 40 further comprises encoder 62. Encoder 62 provides closed-loop feedback control that allows for precise control of motor speed and position of motor 40. In an exemplary embodiment, encoder 62 is arranged in rotor brake 60, as shown in FIGS. 7-8 and 10-11. In an exemplary embodiment, encoder 62 is arranged in motor 40, as shown in FIG. 9. In an exemplary embodiment, encoder 62 is a slim encoder, or very compact in an axial direction, to facilitate a compact powertrain assembly 30.

[0051] Gearbox or speed reducer 70 comprises input end 72, output end 74, and gearbox output 76. Input end 72 is connected to motor 40. Specifically, rotor 52, namely rotor shaft 56, is non-rotatably connected to an input (e.g., shaft, gear, sun, etc.) of gearbox 70. Gearbox 70 comprises a gear train or series of integrated gears to change the angular velocity of rotor shaft 56. For example, gearbox 70 may reduce the angular velocity of rotor shaft 56, through a series of gears arranged therein, and output the reduced angular velocity via gearbox output 76. Thus, the angular velocity of gearbox output 76 is different than (e.g., less than) the angular velocity of rotor shaft 56. In an exemplary embodiment, gearbox 70 distributes torque transmission onto multiplecontact pairs and has a very high engagement ratio to reduce the axial length requirement for each contact pair.

[0052] In an exemplary embodiment, gearbox 70 comprises a cycloidal gearbox as shown in FIGS. 10-11. The cycloidal gearbox may comprise, for example, an 11 : 1 reduction.

[0053] In an exemplary embodiment, gearbox 70 comprises a planetary gearbox as shown in FIG. 12. In an exemplary embodiment, the planetary gearbox may comprise a two stage 11 : 1 reduction gearbox having a slim package. In an exemplary embodiment, the planetary gearbox may comprise eight diametral pitch / 25 degree pressure angle, three planets per stage, a 3.314 ratio per stage, a 10.989: 1 overall ratio, a mechanical efficiency of 98.26% (not including oil churning losses), and a peak torque gear bending stress at 2007 N-m of 53,000 psi. In an exemplary embodiment, the planetary gearbox may comprise an overall ratio of 10.6: 1, 8.870: 1, 8.01 : 1, or 5.85:1.

[0054] Output carrier 80 comprises disk portion 82 and protrusion 84 extending from disc portion in axial direction AD2. In an exemplary embodiment, the diameter of disk portion 82 is greater than the diameter of protrusion 84, which aids in the compact design of powertrain 30. Disk portion 82 is non-rotatably connected to gearbox output 76. Thus, output carrier 80 rotates with gearbox output 76. Disk portion 82 may be connected to gearbox output 76 via any suitable means, for example, bolts, rivets, screws, nails, adhesive, welding, brazing, dowels, etc. In an exemplary embodiment, the diameter of disk portion 82 is substantially equal to the diameter of gearbox output 76. Protrusion 84 forms axial surface 86 and radially outward facing surface 88.

[0055] Plate 90 generally comprises a flange portion including surface 92 and surface 94, protrusion 96 extending from surface 94 in axial direction AD2, and radially inward facing surface 100. In an exemplary embodiment, plate 90 further comprises hole 102 extending from surface 92 in axial direction AD2. Hole 102 is operatively arranged to at least partially enclose output carrier 80 to facilitate a compact arrangement of powertrain 30. Specifically, surface 92 is arranged to be non-rotatably connected to gearbox 70, namely end 74, such that disk portion 82 is arranged in hole 102. Protrusion 96 forms axial surface 98. Bearing 104 is arranged radially between radially outward facing surface 88 and radially inward facing surface 100. In an exemplary embodiment, bearing 104 is press fit onto radially outward facing surface 88 and / or into radially inward facing surface 100. In an exemplary embodiment, plate 80 and bearing 104 are completely enclosed, axially and radially, within plate 90. In an exemplary embodiment, bearing 104 comprises a four-point contact bearing, for example, a KAYDON® KG090XP0 four-point contact bearing. Tn an exemplary embodiment, bearing 104 comprises a four-point contact bearing with needle roller. The needle roller may be added for extra moment and radial load carrying. Plate 90 may be connected to gearbox 70 via any suitable means, for example, bolts, rivets, screws, nails, adhesive, welding, brazing, dowels, etc.

[0056] Plate 90 is operatively arranged to engage chassis 20 to connect powertrain 30 to chassis 20. For example, protrusion 96 is inserted into hole 26 of inner wall 22, in axial direction AD2, as best shown in FIG. 8. Surface 94 abuts against the inner surface of inner wall 22. Protrusion 96 engages hole 26 and extends axially into the space between inner wall 22 and outer wall 24. In an exemplary embodiment, the diameter of protrusion 96 is substantially the same as the diameter of hole 26. The flange portion of plate 90 may then be secured to inner wall 22 to secure powertrain 30 to chassis 20 via any suitable means, for example, bolts, rivets, screws, nails, adhesive, welding, brazing, dowels, etc. In an exemplary embodiment, the arrangement of plate 90 with inner wall 22 forms a rabbet fit.

[0057] Output shaft 110 is non-rotatably connected to output carrier 80 and extends therefrom in axial direction AD2. Output shaft 110 comprises end 112, end 114, flange 116, and radially outward facing surface 118. In an exemplary embodiment, flange 116 is arranged proximate end 112 and has a diameter that is greater than the diameter of radially outward facing surface 118. Flange 116 is arranged to be non-rotatably connected to output carrier 80, specifically, axial surface 86. Flange 116 may be connected to axial surface 86 via any suitable means, for example, bolts, rivets, screws, nails, adhesive, welding, brazing, dowels, etc. In an exemplary embodiment, and as shown, end 112 engages a hole in axial surface 86, which provides added rigidity throughout powertrain 30 while maintaining an axially compact design.

[0058] Sprocket assembly 120 is operatively arranged to be non-rotatably connected to output shaft 110. Sprocket assembly 120 comprises at least one sprocket, for example, sprocket 122 and sprocket 124, and radially inward facing surface 126. In an exemplary embodiment, radially inward facing surface 126 is keyed to radially outward facing surface 118, for example, via one or more splines or one or more press pins. In an exemplary embodiment, and as best shown in FIG. 11, output shaft 110 and sprocket assembly 120 are integrally formed as a single component. In an exemplary embodiment, one of sprocket 122 and sprocket 124 is non-rotatablyengaged with chain 8 and the other of sprocket 122 and sprocket 124 is non-rotatably engaged with chain 10.

[0059] Cover or housing or bracket 130 is operatively arranged to at least partially enclose output shaft 110 and / or sprocket assembly 120. In an exemplary embodiment, bracket 130 comprises cylindrical or housing portion 132 including end 134 and end 136. In an exemplary embodiment, bracket 130 comprises flange 138 arranged at end 134 and extending radially outward therefrom. End 134 is non-rotatably connected to plate 90. Specifically, flange 138 is secured to axial surface 98 via any suitable means, for example, bolts, rivets, screws, nails, adhesive, welding, brazing, dowels, etc. End 136 comprises an axial plate including hole 142 extending in axial direction AD2 therein. Hole 142 forms radially inward facing surface 144 arranged to engage end 114 of output shaft 110. Specifically, bearing 150 is arranged in hole 142 such that bearing 150 is arranged radially between radially inward facing surface 144 and radially outward facing surface 118. In an exemplary embodiment, bearing 150 is press fit into radially inward facing surface 144 or press fit onto radially outward facing surface 118. In an exemplary embodiment, bearing 150 comprises a four-point contact bearing or a four-point contact bearing with needle roller. Bearing 104 and bearing 150 straddle sprocket assembly 120 and output shaft 110 to lower moment and radial loading thereon.

[0060] Bracket 130 comprises at least one window such that chain 8, 10 can pass therethrough to engage sprocket assembly 120. In an exemplary embodiment, and as shown in FIGS. 6-7 and 13, bracket 130 comprises windows 140A-140D. Referring now to FIG. 13, chain 8 passes through window 140C and window 140A to engage sprocket 124 and axle 4. Chain 10 passes through window 140D and window 140B to engage sprocket 122 and axle 6.

[0061] FIG. 9 is a partial cross-sectional view of electric movable machine 2 taken generally along line 5-5 in FIG. 1, showing a second embodiment of powertrain assembly 30. Powertrain assembly 30 as shown in FIG. 9 has substantially the same elements as powertrain assembly 30 in FIG. 8. However, as shown in FIG. 9, rotor brake 60 is arranged axially between motor 40 and gearbox 70. In an exemplary embodiment, rotor brake 60 and motor 40 are integrally formed as one component and / or share the same housing.

[0062] Also shown in FIG. 9 is bracket 130 embodied as a plate. Bracket 130 may be connected to chassis 20, for example, outer wall 24. Output shaft 110 engages hole 142 and bearing 150 is arranged radially between radially outward facing surface 118 and radially inward facingsurface 144. Bracket 130 may be connected to outer wall 24 via any suitable means, for example, bolts, rivets, screws, nails, adhesive, welding, brazing, dowels, etc. The arrangement shown in FIG. 9 allows force to be distributed across both inner wall 22 and outer wall 24 of chassis 20. The arrangement shown in FIG. 9 also eliminates the need for windows in bracket 130.

[0063] FIG. 10 is a sectional view of a third embodiment of powertrain assembly 30 shown in FIG. 1. FIG. 10 shows rotor shaft 56 extending into both rotor brake 60 and cycloidal gearbox 70. Rotor brake 60 is operatively arranged to engage rotor shaft 56 and thereby slow the angular velocity thereof. Also shown in FIG. 10 is flange 106. Flange 106 is connected to plate 90 and extends radially inward to engage bearing 104. Flange 106 is operatively arranged to secure bearing 104 radially between plate 90 and output carrier 80. Likewise, flange 116 of output shaft 110 extends radially outward to engage bearing 104, thereby securing bearing 104 radially between plate 90 and output carrier 80. In an exemplary embodiment, motor 40, gearbox 70, and plate 90 are secured together via one or more bolts. Encoder 62 is arranged in rotor brake 60.

[0064] FIG. 11 is a partial cross-sectional view of electric movable machine 2 taken generally along line 5-5 in FIG. 1, showing a fourth embodiment of powertrain assembly 30. FIG. 11 shows a cross-sectional view of cycloidal gearbox 70 and its connection to output shaft 56. Arrow A illustrates an exemplary embodiment torque path through powertrain 30.

[0065] FIG. 12 is a partial cross-sectional view of a fifth embodiment of powertrain assembly 30. FIG. 12 shows a cross-sectional view of planetary gearbox 70.

[0066] To assembly powertrain 30 onto electric movable machine 2, rotor brake 60 is connected to motor 40. As previously described, rotor brake 60 can be connected to end 42 or end 44 of motor 40. Gearbox 70 is connected to motor 40 or rotor brake 60. Specifically, input end 72 of gearbox 70 is connected to end 44 of motor 40, or rotor brake 60 (in the embodiment shown in FIG. 9). Rotor shaft 56 is non-rotatably connected to at least one element within gearbox 70. Output carrier 80 is connected to gearbox 70. Specifically, output carrier 80 is non-rotatably connected to gearbox output 76. Plate 90 is connected to gearbox 70. Bearing 104 arranged radially between plate 90 and output carrier 80.

[0067] Plate 90 is connected to chassis 20. Specifically, protrusion 96 is engaged with hole 26 in inner wall 22 such that surface 94 abuts against the inner surface of inner wall 22 and protrusion 96 extends at least partially through hole 26. In an exemplary embodiment, surface 98 is arranged axially between inner wall 22 and outer wall 24. Output shaft 110 is connected tooutput carrier 80. Sprocket assembly 120 is connected to output shaft 110. Chain 8, 10 is attached to sprocket assembly 120. For example chain 8 is attached to sprocket 124 and axle 4 and chain 10 is attached to sprocket 122 and axle 6. Bracket 130 is connected to plate 90. Bearing 150 is arranged radially between radially inward facing surface 144 of bracket 130 and output shaft 110.

[0068] In an exemplary embodiment, stiffeners may be used directly in between inner wall 22 and outer wall 24 of chassis 20. For example, stiffeners may be arranged surrounding sprocket assembly 120. The stiffeners may be welded or bolted onto chassis 20. In an exemplary embodiment, pipes can be arranged to stiffen chassis 20 and / or provide added securement for powertrain assembly 30.

[0069] In an exemplary embodiment, the present disclosure provides a powertrain assembly 30 that is compact, rigid, robust to withstand field use and increase reliability, easy to assemble, and for an electrified vehicle. In an exemplary embodiment, the present disclosure provides rotor brake 60 that is capable of handling inertia of an electric system, a bearing support system that lowers moment and radial loading on output shaft 110 and sprocket assembly 120, and a rigid gear drive section and bearings. Moreover, the compact design of the present disclosure powertrain frees up space on the vehicle for a larger battery or battery pack.

[0070] This disclosure has been described in detail with particular reference to an embodiment, but it will be understood that variations and modifications can be effected within the spirit and scope of the disclosure. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restrictive. The scope of the disclosure is indicated by the appended claims, and all changes that come within the meaning and range of equivalents thereof are intended to be embraced therein.LIST OF REFERENCE NUMERALSElectric movable machine 74 EndAxle 76 Gearbox outputAxle 80 Output carrierChain 82 PortionChain 84 ProtrusionWheels or track 86 Axial surfaceWork tool 88 Radially outward facing surfaceArms or booms 90 PlateBattery 92 SurfaceChassis 94 SurfaceInner wall 96 ProtrusionOuter wall 98 Axial surfaceHole 100 Radially inward facing surfacePowertrain 102 HoleDrivetrain 104 BearingMotor 106 FlangeEnd 110 Output shaftEnd 112 EndFlange 114 EndHoles 116 FlangeStator 118 Radially outward facing surfaceRotor 120 Sprocket assemblyShaft 122 SprocketPorts 124 SprocketPorts 126 Radially inward facing surfaceRotor brake 130 Cover or housing or bracketEncoder 132 Cylindrical or housing portionGearbox 134 EndEnd 136 End138 Flange A Arrow140 A Window ADI Axial directionMOB Window AD2 Axial direction140C Window CD1 Circumferential direction140D Window CD2 Circumferential direction142 Hole RD1 Radial direction144 Radially inward facing surface RD2 Radial direction150 Bearing X Axis of rotation

Claims

CLAIMSWhat is claimed is:

1. A drivetrain assembly for an electric movable machine, the drivetrain assembly comprising: a gearbox including: an input end; an output end; and an output carrier arranged at the output end; a plate, including: a first surface connected to the gearbox; a protrusion forming an axial surface; and a first radially inward facing surface, wherein a first bearing is arranged radially between the first radially inward facing surface and the output carrier; an output shaft non-rotatably connected to the output carrier; and a bracket connected to the plate and comprising a second radially inward facing surface, wherein a second bearing is arranged radially between the second radially inward facing surface and the output shaft.

2. The drivetrain assembly as recited in claim 1, wherein the bracket comprises: a housing portion that at least partially encloses the output shaft; and a flange portion fixedly secured to the plate.

3. The drivetrain assembly as recited in claim 2, wherein the housing portion comprises at least one window extending radially therethrough.

4. The drivetrain assembly as recited in claim 1, further comprising a sprocket assembly non- rotatably connected to the output shaft.

5. The drivetrain assembly as recited in claim 4, wherein the sprocket assembly comprises: a first sprocket; and a second sprocket separated from the first sprocket in an axial direction.

6. The drivetrain assembly as recited in claim 4, further comprising a chain engaged with the sprocket assembly.

7. The drivetrain assembly as recited in claim 1, wherein the gearbox comprises a cycloidal gearbox.

8. The drivetrain assembly as recited in claim 1, wherein the gearbox comprises a planetary gearbox.

9. A powertrain assembly for an electric movable machine, the powertrain assembly comprising: a motor; and a drivetrain assembly, including: a gearbox comprising: an input end connected to the motor; an output end; and an output carrier arranged at the output end; a plate, comprising: a first surface connected to the gearbox; a protrusion forming an axial surface; and a first radially inward facing surface, wherein a first bearing is arranged radially between the first radially inward facing surface and the output carrier; an output shaft non-rotatably connected to the output carrier; and a bracket element connected to the plate and comprising a second radially inward facing surface, wherein a second bearing is arranged radially between the second radially inward facing surface and the output shaft.

10. The powertrain assembly as recited in claim 9, wherein the bracket element comprises: a housing portion that at least partially encloses the output shaft; and a flange portion fixedly secured to the plate.

11. The powertrain assembly as recited in claim 10, wherein the housing portion comprises at least one window extending radially therethrough.

12. The powertrain assembly as recited in claim 11, wherein: the at least one window comprises a first window and a second window spaced apart in a circumferential direction from the first window; and a chain extends through the first window and the second window and engages the output shaft.

13. The powertrain assembly as recited in claim 9, further comprising a sprocket assembly non-rotatably connected to the output shaft.

14. The powertrain assembly as recited in claim 13, wherein the sprocket assembly comprises: a first sprocket; and a second sprocket separated from the first sprocket in an axial direction.

15. The powertrain assembly as recited in claim 13, further comprising a chain engaged with the sprocket assembly.

16. The powertrain assembly as recited in claim 9, further comprising a rotor brake connected to the motor, the motor being arranged axially between the rotor brake and the gearbox.

17. The powertrain assembly as recited in claim 9, further comprising a rotor brake connected to the motor, the rotor brake being arranged axially between the motor and the gearbox.

18. The powertrain assembly as recited in claim 9, further comprising an encoder.

19. An electric movable machine, comprising: a chassis including: an inner wall comprising a hole; and an outer wall separated from the inner wall in an axial direction; and a drivetrain assembly, including: a gearbox comprising: an input end; an output end; and an output carrier arranged at the output end; a plate connected to the inner wall, comprising: a first surface connected to the gearbox; a protrusion forming an axial surface, the protrusion extending through the hole in the axial direction; and a first radially inward facing surface, wherein a first bearing is arranged radially between the first radially inward facing surface and the output carrier; and an output shaft non-rotatably connected to the output carrier.

20. The electric movable machine as recited in claim 19, further comprising a bracket element connected to the plate and comprising a second radially inward facing surface, wherein a second bearing is arranged radially between the second radially inward facing surface and the output shaft.

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