Modular Electric Axle Assembly for Banjo Housing

Abstract

An electric axle assembly includes an electric drive unit mounted within a banjo-type axle housing. The electric drive unit includes a motor, a gearbox, and a differential within the housing. The electric drive unit is inserted into the banjo-type axle housing from a first side of the banjo-type axle housing so that at least a portion of the electric drive unit housing is received within the banjo-type axle housing. Fasteners are installed from a second side of the banjo-type axle housing opposite the first side to secure the electric drive unit housing to the banjo-type axle housing.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Non-provisional Application No. 18 / 543,250, filed December 18, 2023, U.S. Provisional Application No. 63 / 441,654, filed January 27, 2023, and U.S. Provisional Application No. 63 / 451,660, filed March 13, 2023, the entire disclosures of which are incorporated herein by reference.

[0002] Technical Field The present disclosure relates generally to electric axles, and more particularly to a housing for an electric axle assembly. [Background technology]

[0003] Generally, an electric axle is a known structure used in automobiles. The electric axle includes several components and is intended to minimize vehicle installation space. It is desirable for the electric axle to utilize lightweight materials to maintain efficiency. Summary of the Invention [Means for solving the problem]

[0004] An embodiment of the present disclosure provides an electric axle assembly including a banjo axle housing and an electric drive unit. In one example, the banjo axle housing includes an upper member and a lower member attached to the upper member, the upper member and the lower member being formed from a stamped structure. The electric drive unit has a housing, and the electric drive unit is mounted within and connected to the banjo axle housing. In an embodiment, a reinforcing plate is attached to the rear side of the banjo axle housing, and a portion of the electric drive unit housing is secured to the banjo axle housing and the reinforcing plate via a bolted connection.

[0005] According to one aspect of the present disclosure, an electric axle assembly includes a banjo-style axle housing including an upper member and a lower member attached to the upper member, and an electric drive unit having a housing. The electric drive unit is mounted within and connected to the banjo axle housing.

[0006] The banjo-type axle housing may include a central portion defining a hollow interior configured to receive a portion of the electric drive unit housing, and two beam portions extending axially away from the central portion on opposite sides. The central portion may include a front wall on a first side thereof, the front wall may define a carrier opening extending into the hollow interior of the central portion, and the central portion may include a rear wall on a second side opposite the first side, wherein at least a portion of the electric drive unit housing may extend through the carrier opening and be received in the hollow interior of the central portion of the banjo-type axle housing. A reinforcing plate may be attached to the rear wall of the central portion of the banjo-type axle housing, and the electric drive unit may be secured to the banjo-type axle housing and the reinforcing plate via a bolted connection. The bolted connection may include a plurality of bolts inserted through the rear wall from the second side of the central portion and received in corresponding holes in the electric drive unit housing. A reinforcing ring may be interposed between the front wall of the central portion and the electric drive unit housing. The housing of the electric drive unit may include an opening and a cover plate surrounding the opening. The cover plate may include a sealing flange adapted to be telescopically received in the opening of the housing, and the sealing flange may support a sealing element for sealing against the inner surface of the housing. The sealing element may include an O-ring supported in a groove in the sealing flange and / or an overmolded seal on at least the sealing flange. The cover plate may include a peripheral mounting flange including a plurality of openings, and a plurality of bolts may extend through the openings in the peripheral mounting flange of the cover plate. The mounting flange may be perpendicular to the sealing flange and extend outward from the sealing flange. The cover plate may be press-fit into the opening of the housing. The upper and lower members may be stamped structures.

[0007] According to another aspect, a method of assembling an electric axle assembly includes providing a banjo-style axle housing having an opening on a first side and a hollow interior; providing an electric drive unit having a housing; inserting the electric drive unit through the opening such that at least a portion of the housing is received in the hollow interior of the banjo-style axle housing; and securing the electric drive unit housing within the banjo-style axle housing with at least one fastener installed from a second side of the banjo-style housing opposite the first side.

[0008] Securing the electric drive unit housing within the banjo-type housing can include inserting a plurality of bolts through a rear wall of the banjo-type housing and into threaded holes in the electric drive unit housing, and tightening the plurality of bolts.

[0009] Further embodiments are disclosed herein.

[0010] The foregoing summary, as well as the following detailed description, can be better understood when read in conjunction with the accompanying drawings, which illustrate preferred embodiments of the present disclosure. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a rear perspective view of an exemplary electric axle assembly including a banjo axle housing and an electric drive unit according to the present disclosure. [Figure 2] FIG. 2 is a front perspective view of the electric axle assembly of FIG. 1. [Figure 3] 3 is a cross-sectional view of the electric axle assembly of FIG. 1 taken along line 3-3 of FIG. 2. [Figure 4] FIG. 2 is a rear perspective view of the electric drive unit of FIG. 1. [Figure 5] FIG. 5 is a rear perspective, partially exploded view of the electric drive unit of FIG. 4. [Figure 6] FIG. 2 is a front perspective view of the banjo axle of FIG. 1. [Figure 7]FIG. 2 is a rear perspective, partially exploded view of the banjo axle of FIG. 1. [Figure 8] FIG. 8 is a perspective cross-sectional view of the electric axle assembly taken along line 8-8 in FIG. 1. [Figure 9] FIG. 8 is a cross-sectional view of the electric axle assembly taken along line 8-8 in FIG. 1. [Figure 10] FIG. 2 is an exploded rear perspective view of the banjo axle housing of FIG. 1. [Figure 11] FIG. 2 is an exploded front perspective view of the banjo axle housing of FIG. 1. [Figure 12] FIG. 1 is a cross-sectional view illustrating a first alternative cover seal configuration according to the present disclosure. [Figure 13] FIG. 13 is a partially enlarged view of FIG. [Figure 14] FIG. 10 is a cross-sectional view illustrating a second alternative cover seal configuration according to the present disclosure. [Figure 15] FIG. 1 is a perspective view of an exemplary cover according to the present disclosure. [Figure 16] FIG. 16 is a partially enlarged view of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] In the following description, certain terminology is used for convenience only and is not limiting. The terms "front," "rear," "upper," and "lower" refer to directions in the drawings to which reference is made. The terms "inwardly" and "outwardly" refer to directions toward and away from the part to which reference is made in the drawings. "Axially" refers to a direction along the axis of the shaft. Reference to a list of items recited as "at least one of a, b, or c" (where a, b, and c represent the listed items) means any one of items a, b, or c, or any combination thereof. Terminology includes the words specifically mentioned above, derivatives thereof, and words of similar import.

[0013] Embodiments of the present disclosure are described herein. It should be understood that like drawing numbers appearing in different drawings identify identical or functionally similar structural elements. It should also be understood that the disclosed embodiments are merely examples, and that other embodiments may take various alternative forms. The figures are not necessarily to scale, and some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein should not be construed as limiting, but merely as representative references to teach those skilled in the art various uses of the embodiments. As one skilled in the art will understand, various features illustrated and described with reference to any one of the drawings can be combined with features illustrated in one or more other drawings to produce embodiments not explicitly illustrated or described. The combination of illustrated features provides a representative embodiment for a typical application. However, various combinations and modifications of features consistent with the teachings of the present disclosure may be desired for a particular application or implementation.

[0014] The terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the present disclosure. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods, devices, or materials similar or equivalent to those described herein can be used in the practice or testing of the present disclosure, the following exemplary methods, devices, and materials are described herein.

[0015] Embodiments of the present disclosure provide an electric axle assembly that includes an electric motor, gearbox, and differential within an aluminum housing that is then suspended or mounted within a stamped steel banjo axle. The electric axle assembly is mounted and assembled in a modular and easily serviceable manner.

[0016] 1-9, and initially with reference to FIGS. 1-3, electric axle assembly 100 includes an electric drive unit 102 that is at least partially mounted or suspended within an axle housing 104, which may be in the form of a banjo axle. As described in detail below, electric drive unit 102 includes a portion thereof that is telescopically received within a portion of axle housing 104. That is, a portion of electric drive unit 102 is telescopically nested within, secured to, and / or supported by axle housing 104. Thus, electric drive unit 102 can be assembled and / or disassembled as a unit with axle housing 104 to form electric axle 100.

[0017] 4 and 5, electric drive unit 102 includes a housing 106, an electric motor 108, a power electronics unit (PEU) 110, a gearbox 112, and a differential 114. For example, housing 106 may be formed from aluminum, and axle housing 104 may be formed from steel and stamped construction.

[0018] 6 and 7 , axle housing 104 includes an enlarged central or banjo portion 116 defining a hollow interior 118 configured to receive a portion of electric drive unit 102 therein. Central portion 116 further includes a rear wall 120 disposed on a rearward-facing side thereof and a front carrier opening 122 formed therethrough on a forward-facing side thereof, such that a portion 124 of housing 106 is received through front carrier opening 122 bounded by front carrier wall 126 and abuts rear wall 120 when assembled with axle housing 104.

[0019] 8 and 9 , at least a portion of housing 106 of electric drive unit 102 is received within and secured to a back surface of axle housing 104. For example, portion 124 of housing 106 that houses differential component 129 of electric drive unit 102 may include a side wall 130 having a plurality of first openings 132 (e.g., threaded holes) configured to receive bolts 134 to secure electric drive unit 102 to axle housing 104, particularly rear wall 120 and holes 136 formed therein. In this manner, electric drive unit 102 may be secured within banjo housing 104 via a bolted connection.

[0020] Referring to FIG. 10 , the axle housing 104 may be formed from a stamped construction and includes an upper half member or section 140 and a lower half member or section 142 attached to one another along abutting adjacent sidewall edges. The upper and lower half members 140, 142 may be attached to one another via welds 144, 146 and, together, may form a substantially rectangular cross-section at tube sections 148, 150 and at the central portion 116 (see FIG. 3 ) when assembled. First and second tube or beam sections 148, 150 extend axially outward from opposite sides of the central portion 116 to accommodate respective axle shafts 151 a, 151 b. To assemble, a portion 124 of the housing 106 of the electric drive unit 102 is assembled or inserted through the forward carrier opening 122, received within the hollow interior 118, and secured via bolts 134.

[0021] The axle housing 104 may further include a reinforcing ring 154 attached to the forward carrier wall 126, for example, via a weld 156. The reinforcing ring 154 provides additional rigidity around the forward carrier opening 122. The top surface of the reinforcing ring 154 may then be machined flat to maintain constant contact with the housing 102, particularly the flange 158, during assembly. The axle housing 104 may further include a back cover or reinforcing plate 160 configured to be secured to the rear wall 120 of the housing 104 and the side wall 130 of the housing 106 via bolts 134. That is, the bolts 134 may be inserted through openings 162 in the back cover 160 and through openings 136 formed in the rear wall 120 of the banjo housing 104 to be received in a plurality of second openings 163 (e.g., threaded holes) formed in the side wall 130 of the housing 106. The back cover or reinforcing plate 160 may be further attached to the banjo housing 104 via the weld 164. The back cover 160 is configured to act as a stiffening plate and surrounds the hollow interior 118 to prevent leakage from the assembly. The back cover or stiffening plate 160 may be formed, for example, by a stamped construction.

[0022] In some embodiments, the housing 106 may further include a rear opening and a cover plate 170 secured to the housing 106 to close / seal internal components (e.g., a differential) from the exterior of the housing 106. The cover plate 170 includes an opening 172 formed therein. A flange 174 having an opening 176 formed therein may be disposed between the side wall 130 and the cover plate 170 and configured to act as a sealing mechanism therebetween. The cover plate 170 may be secured to the housing 106 via a bolt 178. That is, the bolt 178 may be inserted through the opening 172 of the cover plate 170 and the opening 176 of the flange 174 so as to be received in the first opening 132 formed in the side wall 130 of the housing 102. The rear wall 120 of the banjo housing 104 may further include a recess 182 for clearance of the bolt head of the bolt 178. The cover plate 170 may be formed, for example, from a stamped structure. Housing 106 may further include a sealing element 180 disposed between flange 158 and stiffening ring 154 to prevent contaminants from entering banjo housing 104. In some embodiments, the sealing element may be formed from a porous material such as foam or rubber and may be configured to be axially deformable.

[0023] 12 and 13, an alternative exemplary sealing configuration is shown for sealing the cover plate 170a to the housing 106. In this example, the separate flange seal element 180 is eliminated, and the cover 170a, which may also be referred to as a seal plate, includes a sealing flange 190 adapted to be received within the housing 106 to seal against an inner surface 192 of the housing 106. The sealing flange 190 includes a groove 194 for receiving a sealing element, such as an O-ring 196. The cover 170a includes a mounting flange 198 adapted to be interposed between the housing 106 and the banjo housing 104 and secured by bolts 132 and / or 178 as previously described.

[0024] In this example, the seal interface is the interior surface of the housing 106 (as compared to the end surface of the housing 106 in the case of flange seal element 180). In certain applications, the seal configurations of Figures 12 and 13 provide improved sealing performance because the seal interface is not associated with the mounting interface between the housing 106 and banjo housing 104. Additionally, the mounting flange 194 maintains metal-to-metal contact with the housing 106 around the entire perimeter of the cover 170a, thus preventing leakage of electromagnetic interference.

[0025] 14-16 show another exemplary seal configuration for sealing the cover 170b to the housing 106. In this example, the separate flange 174 is eliminated, and the cover 170b includes a sealing flange 190. The sealing flange 190 in this embodiment defines the outer periphery of the cover 170b and is adapted to be received within the housing 106 to seal against an inner surface 192 of the housing 106. The cover 170b is adapted to be press-fit into the housing 106. A sealing element 200 is overmolded or otherwise adhered to the cover 170b around its periphery, including the sealing flange 190. In one example, the sealing element 200 may include a highly compressible ribbed seal configuration. The cover 170b may be stamped or cast metal, such as steel or aluminum, or injection-molded plastic. In this embodiment, the cover 170b is isolated from the connection interface between the housing 106 and the banjo housing 104. That is, cover 170b is not exposed to any stresses that may be present at the connection interface between housing 106 and banjo housing 104.

[0026] Several advantages are achieved through the use of the embodiments disclosed herein, including providing a durable, modular, energized axle assembly, thereby improving maintainability. The embodiments provide a durable assembly constructed from lighter materials, such as aluminum, which offers weight and cost savings.

[0027] Although the illustrated exemplary embodiment shows the electric drive unit 102 extending forward from the banjo-style axle housing, it should be understood that in other embodiments, the electric drive unit 102 (or other components) may be supported by the banjo-style axle housing and may extend in other directions, such as rearward, upward, downward, etc., without departing from the scope of the present disclosure.

[0028] It should also be appreciated that the electric drive unit 102 and axle shafts 151 a, 151 b comprise a fully sealed / housed power axle assembly supported by a banjo-style axle housing, allowing the electric drive unit 102 and axle shafts 151 a, 151 b to be removed and installed from the banjo-style axle housing while the banjo-style axle housing remains installed in the vehicle.

[0029] While exemplary embodiments have been described above, these embodiments are not intended to describe all possible forms encompassed by the claims. The terms used herein are terms of description rather than limitation, and it is understood that various changes can be made without departing from the spirit and scope of the present disclosure. As described above, features of various embodiments can be combined to form further embodiments of the present disclosure that may not be explicitly described or illustrated. While various embodiments have been described as offering advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those skilled in the art will recognize that one or more features or characteristics may be compromised to achieve desired overall system attributes depending on the particular application and implementation. These attributes may include, but are not limited to, cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, maintainability, weight, manufacturability, ease of assembly, and the like. Thus, to the extent that any embodiments are described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics, these embodiments are not outside the scope of the present disclosure and may be desirable for particular applications.

[0030] Having thus described the present embodiment in detail, it will be understood, and will be apparent to those skilled in the art, that many physical changes, only a few of which are illustrated in the detailed description of this disclosure, can be made without altering the concepts and principles of the present invention embodied therein.

[0031] It should also be understood that many embodiments are possible that incorporate only portions of the preferred embodiment, and that, with respect to those portions, do not change the concepts and principles of the present invention embodied therein.

[0032] The present embodiments and optional configurations are therefore considered in all respects to be illustrative and / or explanatory and not restrictive, the scope of the present disclosure being indicated by the appended claims rather than the foregoing description, and all alternative embodiments and modifications to the present embodiments that come within the meaning and range of equivalents of the claims are therefore intended to be embraced therein. [Explanation of symbols]

[0033] 100 Electric Axle Assembly 102 Electric Drive Unit 104 Axle housing 106 Housing 108 Electric Motor 110 Power Electronics Unit 112 Gearbox 114 Differential device 116 Banjo Club 118 Hollow interior 120 Back wall 122 Carrier opening 124 (part of housing 106) 126 Carrier Wall 129 Differential Components 130 Side wall 132 First Opening 134 volts 136 holes 140 Upper half member 142 Lower half member 144 Welded Section 146 Welded Section 148 Pipe section 150 Pipe section 151a axle shaft 151b axle shaft 154 Reinforcement Ring 158 flange 160 back cover 162 Aperture 163 Aperture 164 Welded Section 170 Cover Plate 170a Cover Plate 170b cover plate 172 Aperture 174 flange 176 Aperture 178 volts 180 sealing element 182 recess 190 Seal flange 192 Inside 194 Groove 196 O-ring 198 Mounting flange 200 stickers

Claims

1. A banjo-type axle housing, An upper member; a lower member attached to the upper member; a banjo-type axle housing including: an electric drive unit having a housing; Equipped with An electric axle assembly, wherein the electric drive unit is mounted within and connected to the banjo-type axle housing.

2. 2. The electric axle assembly of claim 1, wherein the banjo-type axle housing includes a central portion defining a hollow interior configured to receive a portion of the housing of the electric drive unit, and two beam portions extending axially away from the central portion on either side.

3. 3. The electric axle assembly of claim 2, wherein the central portion includes a front wall on a first side thereof defining a carrier opening extending into the hollow interior of the central portion, and a rear wall on a second side opposite the first side, wherein at least a portion of the housing of the electric drive unit extends through the carrier opening and is received in the hollow interior of the central portion of the banjo-style axle housing.

4. The electric axle assembly of claim 3 , wherein the electric drive unit includes a power electronics unit located at a front portion of the housing of the electric drive unit.

5. 4. The electric axle assembly of claim 3, further comprising a reinforcing plate attached to the rear wall of the central portion of the banjo-type axle housing, the electric drive unit being fixed to the banjo-type axle housing and the reinforcing plate via a bolted connection.

6. 6. The electric axle assembly of claim 5, wherein the bolted connection includes a plurality of bolts inserted through the rear wall from the second side of the central portion and received within corresponding holes in the housing of the electric drive unit.

7. The electric axle assembly of claim 6 , further comprising a reinforcing ring interposed between the front wall of the central portion and the housing of the electric drive unit.

8. The electric axle assembly of claim 6 , wherein the housing of the electric drive unit includes an opening and a cover plate surrounding the opening.

9. 9. The electric axle assembly of claim 8, wherein the cover plate includes a sealing flange adapted to be telescopically received in the opening in the housing, the sealing flange supporting a sealing element for sealing against an inner surface of the housing.

10. The electric axle assembly of claim 9 , wherein the sealing element includes an O-ring supported in a groove in the sealing flange.

11. The electric axle assembly of claim 9 , wherein the sealing element includes a seal overmolded onto at least the sealing flange.

12. 10. The electric axle assembly of claim 9, wherein the cover plate includes a perimeter mounting flange including a plurality of openings, and the plurality of bolts extend through the openings in the perimeter mounting flange of the cover plate.

13. The electric axle assembly of claim 12 , wherein the mounting flange is perpendicular to and extends outwardly from the sealing flange.

14. The electric axle assembly of claim 8 , wherein the cover plate is press-fit into the opening in the housing.

15. The electric axle assembly of claim 1 , wherein the upper member and the lower member are stamped structures.

16. The electric axle assembly of claim 1 , further comprising first and second axle shafts coupled to the electric drive unit and supported by the banjo-style axle housing.

17. 1. A method of assembling an electric axle assembly, comprising: Providing a banjo-style axle housing having an opening on a first side and a hollow interior; Providing an electric drive unit having a housing; inserting the electric drive unit through the opening such that at least a portion of the housing is received within the hollow interior of the banjo-style axle housing; securing the housing of the electric drive unit within the banjo-style axle housing with at least one fastener installed from a second side of the banjo-style housing opposite the first side; A method comprising:

18. 18. The method of claim 17, wherein securing the housing of the electric drive unit within the banjo-style housing includes inserting a plurality of bolts through a rear wall of the banjo-style housing and into threaded holes in the housing of the electric drive unit, and tightening the plurality of bolts.

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