DESC:TECHNICAL FIELD
[001] This disclosure relates generally to the field of electric vehicles, more particularly to mounting of the traction motor in the electric vehicle.
BACKGROUND
[002] An electric vehicle (EV), such as an electric small commercial vehicle (SCV), may include a traction motor to propel the EV. The traction motor is to be coupled to the drive wheels of the vehicle to cause propulsion of the EV. To achieve the coupling, in some scenarios, a driveshaft is utilized. The driveshaft may be, for example, a constant velocity (CV) axle shaft. The driveshaft may be utilized in vehicles with an independent suspension system. For instance, the traction motor is mounted on a frame of the EV, and the CV Axle shaft couples the traction motor with the drive wheels. With this arrangement, the traction motor remains stationary even when the EV travel over rugged terrains such as, bumps, potholes, and the like, which improves the stability & reliability of the traction motor.
[003] However, in some cases, the coupling of the traction motor with the drive wheels through the CV axle shaft may not be possible. For instance, when the EV includes a dependent suspension system in which an axle beam connects and distributes various loads and forces evenly between the sides of the vehicle, and also serves as the housing for the differential. This is because the CV Axle shaft may foul with the axle beam.
[004] In the EVs which includes the axle beam, to transfer the drive from the traction motor to the drive wheels without using the driveshaft, typically, the traction motor is directly mounted on the axle beam. However, since the axle beam tends to undergo vibrations during the travel of the EV, the direct mounting causes the traction motor to vibrate. This, in turn, may reduce the reliability and ease of maneuvering of the EV. Further, during a suspension travel, the traction motor moves, causing movement of a plurality of associated wirings and a plurality of cooling conduits of the traction motor, which is undesirable.
[005] Therefore, there is a need for an efficient mounting of the traction motor in EVs.
SUMMARY OF THE INVENTION
[006] In an embodiment, an axle beam is disclosed. The axle beam may include a pair of wheel hub connectors. Further, the axle beam may include a cross-member formed between the pair of wheel hub connectors. The cross-member and the pair of wheel hub connectors may be formed as an open C-shaped channel. Further, the cross-member may be configured to face a traction motor, and the pair of wheel hub connectors is configured to accommodate a pair of driveshafts extending from the traction motor.
[007] In another embodiment, a drivetrain assembly is be disclosed. The drivetrain assembly a traction motor and an axle beam. The axle beam may include a pair of wheel hub connectors. Further, the drivetrain assembly may include a cross-member formed between the pair of wheel hub connectors. The cross-member and the pair of wheel hub connectors are formed as an open C-shaped channel. Further, the cross-member may be configured to face the traction motor, and the pair of wheel hub connectors is configured to accommodate a pair of driveshafts extending from the traction motor.
[008] In yet another embodiment, a vehicle comprising a drivetrain assembly is disclosed. The drivetrain assembly a traction motor and an axle beam. The axle beam may include a pair of wheel hub connectors. Further, the vehicle may include a cross-member formed between the pair of wheel hub connectors. The cross-member and the pair of wheel hub connectors are formed as an open C-shaped channel. Further, the cross-member may be configured to face the traction motor, and the pair of wheel hub connectors is configured to accommodate a pair of driveshafts extending from the traction motor.
[009] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[010] The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate exemplary embodiments and, together with the description, serve to explain the disclosed principles.
[011] FIG. 1 illustrates a perspective view of a chassis of an electrical vehicle (EV), in accordance with some embodiments of the present disclosure.
[012] FIG. 2 illustrates a top view of a drivetrain assembly, in accordance with some embodiments of the present disclosure.
[013] FIG. 3 illustrates a perspective view of an axle beam, in accordance with some embodiments of the present disclosure.
[014] FIG. 4 illustrates a perspective view 400 of the axle beam 124 assembled to a suspension system, in accordance with some embodiments of the present disclosure.
[015] FIG. 5 illustrates a perspective view of the axle beam coupled, in accordance with some embodiments of the present disclosure.
DETAILED DESCRIPTION
[016] The foregoing description has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which forms the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that the conception and specific embodiments disclosed may be readily utilized as a basis for modifying other devices, systems, assemblies, and mechanisms for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that, such equivalent constructions do not depart from the scope of the disclosure as set forth in the appended claims. The novel features which are believed to be characteristics of the disclosure, to its device or system, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.
[017] The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusions, such that a system or a device that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device. In other words, one or more elements in a system or apparatus proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus.
[018] Reference will now be made to the exemplary embodiments of the disclosure, as illustrated in the accompanying drawings. Wherever possible, same numerals have been used to refer to the same or like parts. The following paragraphs describe the present disclosure with reference to FIGs. 1-5. For the sake of clarity an electrical vehicle (EV) is not shown.
[019] As explained earlier, the traction motor may not be mounted effectively on the chassis of the EV. Instead, the traction motor may be mounted on the axle beam. Further, the mounting of the traction motor on the axle beam contributes to an increase in an unsprung mass of the EV. Moreover, when subjected to vibrations from the EV during motion, the axle beam may vibrate which may also result in vibration of the traction motor. Consequently, the handling dynamics may be adversely affected, reliability may be reduced, and the ease of maneuverability of the EV may become less efficient.
[020] Therefore, a mounting of traction motor in an EV is illustrated. The mounting may be established by assembling the traction motor on the chassis, and coupling an axle beam between pair of drive wheels. The axle beam may be configured to accommodate a pair of driveshafts, instead of accommodating the traction motor. Accordingly, such mounting may be configured to reduce the unsprung mass of the EV induced by the traction motor. Further, the unsprung mass may be balanced, and stability and ride handling of the EV may be enhanced. Particularly, each driveshaft may be secured from fouling. Additionally, on encountering the EV in rough terrains the occurrence of vibrations may be prevented.
[021] Now referring to FIG. 1 which illustrates a perspective view 100 of a chassis 102 of an electrical vehicle (EV), in accordance with some embodiments of the present disclosure. In an embodiment, chassis 102 may include a drivetrain assembly 106. The drivetrain assembly 106 may include a traction motor 104 operatively coupled to a pair of wheel hubs 108 and 110. Further, the traction motor 104 may be coupled to a casing 105. The casing 105 may include Power Distribution unit, DC-DC converter, On-Board Charger (OBS) unit, and the like, and coupled to a Motor Control Unit (not shown) of the traction motor 104 via a power harness 107. By way of example, the traction motor 104 may include, but not limited to DC-series motor, brushless motor, permanent magnet synchronous motor (PMSM), induction motor, and the like.
[022] The traction motor 104 may be mounted on the chassis 102. For example, the chassis 102 may include a first long member 112 and a second long member 114 oppositely disposed to the first long member 112. The chassis 102 may further include a first cross-member 116, and a second cross-member 118. The traction motor 104 may be mounted on a portion of the first long member 112 and the second long member 114 between the first cross-member 116 and the second long member 114. Such assembly results in the traction motor 104 being supported by the chassis 102, thereby reducing the unsprung mass of the vehicle.
[023] In an embodiment, the drivetrain assembly 106 may include a pair of driveshafts 120 and 122 extending from the traction motor 104 and coupled to the pair of wheel hubs 108 and 110. The pair of driveshafts 120 and 122 may be configured to transmit motor drive generated by the traction motor 104 to the pair of wheel hubs 108 and 110 through a transmission assembly, and a differential unit (not shown). By way of example, each pair of driveshafts 120 and 122 may include but not limited to, a constant velocity (CV) axle shaft, and the like.
[024] In an embodiment, the drivetrain assembly 106 may include an axle beam 124. The axle beam 124 may be disposed between the first long member 112 and the second long member 114. Further, the axle beam 124 may face the traction motor 104 and disposed between the pair of wheel hubs 108 and 110. The axle beam 124 may be configured to connect the pair of wheel hubs 108 and 110 and in addition, provide support to the weight, and maintain alignment of the EV.
[025] With continued reference to FIG. 1, the chassis 102 may be equipped with a suspension system. The suspension system may include a pair of springs 126 and 128 and a pair of dampers 130 and 132 adjoined to the axle beam 124. By way of example, the pair of springs 126 and 128 may include, but not limited to, leaf springs. For example, referring to FIG. 1, each spring from the pair of springs 126 and 128 may include a leaf spring. Further, the pair of springs 126 and 128 may be coupled to the axle beam 124 either an overslung configuration, or an underslung configuration. In the overslung configuration, the pair of springs 126 and 128 may be coupled to the chassis 102 above the axle beam 124. Further, in the underslung configuration, the pair of springs 126 and 128 may be coupled to the chassis 102 below the axle beam 124. Further, the pair of dampers 130 and 132 may be assembled to the pair of springs 126 and 128. The assembly of the suspension system with the chassis 102, and the axle beam 124 is explained in conjunction with FIG. 5.
[026] FIG. 2 illustrates a top view 200 of the drivetrain assembly 106, in accordance with some embodiments of the present disclosure. The traction motor 104 may include a pair of wheel hub connectors 202 and 204 and a cross-member 206 formed between the pair of wheel hub connectors 202 and 204. Further, the cross-member 206 and the pair of wheel hub connectors 202 and 204 are formed as an open C-shaped channel. Moreover, the cross-member 206 may be configured to face the traction motor 104, and the pair of wheel hub connectors 202 and 204 may be configured to accommodate the pair of driveshafts 120 and 122 extending from the traction motor 104. In an embodiment, the axle beam 124 may be formed as a single structure, or an assembly of one or more components, i.e., the cross-member 206 and the pair of wheel hub connectors 202 and 204 may be separately manufactured and adjoined together.
[027] In an embodiment, the pair of wheel hub connectors 202 and 204 accommodated within the pair of wheel hub connectors 202 and 204 may enable assembly of the casing 105 above the traction motor 104. Accordingly, a length of the power harness 107 may be reduced, and a probability of inflicting damage thereupon may be reduced.
[028] The cross-member 206 may be shaped as a linear structure, and the ends of the linear structure may be transversely shaped and adjoined, or formed with, the pair of wheel hub connectors 202 and 204. The transversed shaped ends of the cross-member 206 enables the pair of wheel hub connectors 202 and 204 to be offset relative to the cross-member 206 by a predefined offset distance. The predefined offset distance may be measured as a distance between axes passing through the pair of wheel hub connectors 202 and 204 and the cross-member 206. For example, referring to FIG. 2, an axis X-X’ may pass through the pair of wheel hub connectors 202 and 204, and an axis Y-Y’ may pass through the cross-member 206. As explained earlier, the pair of wheel hub connectors 202 and 204 may be formed offset to the cross-member 206 by a predefined offset distance, and hence, the axis X-X’ may be offset to the axis Y-Y’. The distance “d” between the axis X-X’ and the axis Y-Y’ may be referred to as the predefined offset distance. Moreover, a portion of the traction motor 104 may pass through the axis X-X’ passing through the pair of wheel hub connectors 202 and 204.
[029] A higher magnitude of the offset distance in conventional axle beams may result in increase in magnitude of torque acting on the axle beam 124. The torque may be a reactive torque to a torque generated by the driveshafts 120 and 122. As a result, the torque may result in twisting of the pair of springs 126 and 128. Therefore, the predefined offset distance herein, may be reduced by a predefined value (for example and 25%) as compared to offset distance in conventional axle beams, to allow a lower magnitude of torque acting on the cross-member 206. Such predefined offset distance being reduced, the magnitude of reactive torque acting on the cross-member 206 may be reduced, and hence, twisting of the pair of springs 126 and 128 coupled to the axle beam 124 may be prevented.
[030] Now, referring to FIG. 3, which illustrates a perspective view 300 of the axle beam 124, in accordance with some embodiments of the present disclosure. As explained earlier, the axle beam 124 may be formed as an open C-shaped channel. Referring to FIG. 3, the opened C-shaped channel may be formed by eliminating a surface in the structure of the axle beam 124. For example, a surface between surfaces 302, 304 may be eliminated, therefore providing the opened C-shaped channel to the axle beam 124. Moreover, the opened C-shaped channel may be formed as a hollow structure to enable accommodation of the pair of driveshafts 120 and 122 between the surfaces 302, 304 at the pair of wheel hub connectors 202 and 204. As such, due to such accommodation, the fouling of the pair of driveshafts 120 and 122 against an outer surface of the axle beam 124 may be prevented. Hence, damage to the pair of driveshafts 120 and 122 and the axle beam 124 may be prevented.
[031] The open C-shaped channel at the cross-member 206 may be narrower than the open C-shaped channel at the pair of wheel hub connectors 202 and 204 by a predefined value. For example, if the gap between surfaces 302 and 304 may be “X1” centimetres (refer to FIG. 5) at the pair of wheel hub connectors 202 and 204, the gap between the surfaces 302 and 304 may be “X2” centimetres (refer to FIG. 5). For example, X2 may be equivalent to 0.7X1.
[032] Referring to FIG. 4, which illustrates a perspective view 400 of the axle beam 124 assembled to the suspension system, in accordance with some embodiments of the present disclosure. FIG. 4 is explained in conjunction with FIGs. 1-3. As explained earlier, the suspension system may be assembled to the axle beam 124. Particularly, the pair of springs 126 and 128 may be adjoined to the axle beam 124 using a plurality of U-bolt fasteners 402 and 404 and a plurality of fastener plates 406 and 408. For example, the spring 126 may be adjoined to the wheel hub connector 202 using the U-bolt fastener 402. For example, the leaf spring 126 may be positioned on the fastener plate 406 and contemporaneously adjoined to the surface 304 of the axle beam 124. Moreover, the U-bolt fasteners 402 may be configured to accommodate the wheel hub connector 202 and may be coupled to the fastener plate 406, thereby securing the leaf spring 126 with the wheel hub connector 202. In a similar manner, the leaf spring 128 may be adjoined to the wheel hub connector 204 using the U-bolt fasteners 404 and the fastener plate 408.
[033] In an embodiment, the shape of the cross-member 206 may allow connection of the pair of dampers 130 and 132 may be assembled to the pair of springs 126 and 128. For example, as explained earlier (in FIG. 2), ends of the cross-member 206 may be transversely shaped. The transversely shaped ends of the cross-member 206 may be configured to allow positioning of the pair of dampers 130 and 132 proximal to the axle beam 124, in addition to preventing fouling of the pair of dampers 130 and 132 with the axle beam 124. For example, the damper 130 may be positioned proximal to the end of the cross-member 206 and coupled to the mounting bracket (not shown), or to the fastener plate 406. Similarly, the damper 132 may be positioned proximal to the end of the cross-member 206 and coupled to the mounting bracket (not shown), or to the fastener plate 408. In such scenarios, the dampers 130 and 132 may not foul with the axle beam 124.
[034] FIG. 5 illustrates a perspective view 500 of the axle beam 124, in accordance with an embodiment of the present disclosure. As explained earlier, the axle beam 124 may include the pair of wheel hub connectors 202 and 204 and the cross-member 206 formed as the open C-shaped channel. Further, the the pair of wheel hub connectors 202 and 204 and the cross-member 206 may be configured to accommodate a plurality of reinforcement members. The plurality of reinforcement members may be configured to reinforce the axle beam 124. The plurality of reinforcement members may include a pair of a first reinforcement bracket 502, a second reinforcement bracket 504, and a reinforcement bar 506. Further, each wheel hub connector 202 and 204 may be configured to accommodate the first reinforcement bracket 502, and second reinforcement bracket 504 respectively. For example, the wheel hub connector 202 may be configured to accommodate the first reinforcement bracket 502, and the wheel hub connector 204 may be configured to accommodate the second reinforcement bracket 504. Further, the cross-member 206 may be configured to accommodate the reinforcement bar 506.
[035] To elaborate further, each of the first reinforcement bracket 502, the second reinforcement bracket 504 may be formed as an open C-shaped member, and may be inversely accommodated within the open C-shaped channel of the pair of wheel hub connectors 202 and 204. The pair of wheel hub connectors 202 and 204 may undergo deformation stress due to clamping action of the U-bolt fasteners 402 and 404, respectively, therefore, the first reinforcement bracket 502 and the second reinforcement bracket 504 may be accommodated within the open C-shaped channel of the pair of wheel hub connectors 202 and 204. Further, the reinforcement bar 506 may also be an open C-shaped bar inversely adjoined to the open C-shaped channel of the cross-member 206. The reinforcement bar 506 may improve ground clearance of the axle beam 124 at a center of the chassis 102 of the EV. The first reinforcement bracket 502 and the second reinforcement bracket 504 may be adjoined to the pair of wheel hub connectors 202 and 204, and the reinforcement bar 506 may be adjoined to the cross-member 206 by using fastening methods commonly known in the art. By way of example, the first reinforcement bracket 502 and the second reinforcement bracket 504 may be secured within the pair of wheel hub connectors 202 and 204 by a pair of bracket fasteners 508 and 510 respectively.
[036] The axle beam 124 described in the various embodiments discussed above are not routine, or conventional or well understood in the art. The axle beam 124 may be capable of offering several advantages. The axle beam 124 enables the use of the pair of driveshafts, such as CV axle shaft, for transferring motor drive of traction motor 104 to the pair of wheel hubs 108 and 110 even in vehicles with dependent suspension systems and axle beams, thereby improving the stability of the traction motor 104 and maneuverability of the vehicle. The stable mounting of the traction motor 104 significantly reduces vibrations on the axle beam. Therefore, the casing and power harness movement and vibrations to the traction motor are reduced drastically. Therefore, the power harness of the EV becomes simpler and safer.
[037] With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.
[038] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”
[039] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.
[040] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims. ,CLAIMS:CLAIMS
I/We Claim:
1. An axle beam (124), comprising:
a pair of wheel hub connectors (202 and 204); and
a cross-member (206) formed between the pair of wheel hub connectors (202 and 204), wherein the cross-member (206) and the pair of wheel hub connectors (202 and 204) are formed as an open C-shaped channel, wherein the cross-member (206) is configured to face a traction motor (104), and the pair of wheel hub connectors (202 and 204) is configured to accommodate a pair of driveshafts (120 and 122) extending from the traction motor (104).
2. The axle beam (124) as claimed in claim 1, wherein the open C-shaped channel at the cross-member (206) is narrower than the open C-shaped channel at the pair of wheel hub connectors (202 and 204) by a predefined value.
3. The axle beam (124) as claimed in claim 1, wherein an axis (Y-Y’) passing through the cross-member (206) is offset to the axis (X-X’) passing through the pair of wheel hub connectors (202 and 204).
4. The axle beam (124) as claimed in claim 3, wherein at least one portion of the traction motor (104) passes through the axis (X-X’) passing through the pair of wheel hub connectors (202 and 204).
5. The axle beam (124) as claimed in claim 1, wherein each wheel hub connector (202 and 204) is configured to accommodate a reinforcement member (602, 604), wherein each reinforcement member (602, 604) comprises an open C-shaped member inversely adjoined to the open C-shaped channel of each wheel hub connector (202 and 204).
6. The axle beam (124) as claimed in claim 1, wherein the cross-member (206) is configured to accommodate a reinforcement bar (606), wherein the reinforcement bar (606) comprises an open C-shaped bar inversely adjoined to the open C-shaped channel of the cross-member (206).
7. A drivetrain assembly (106), comprising:
a traction motor (104); and
an axle beam (124) comprising:
a pair of wheel hub connectors (202 and 204); and
a cross-member (206) formed between the pair of wheel hub connectors (202 and 204), wherein the cross-member (206) and the pair of wheel hub connectors (202 and 204) are formed as an open C-shaped channel, wherein the cross-member (206) is configured to face the traction motor (104), and the pair of wheel hub connectors (202 and 204) is configured to accommodate a pair of driveshafts (120 and 122) extending from the traction motor (104).
8. The drivetrain assembly (106) as claimed in claim 7, wherein the open C-shaped channel at the cross-member (206) is narrower than the open C-shaped channel at the pair of wheel hub connectors (202 and 204) by a predefined value.
9. The drivetrain assembly (106) as claimed in claim 7, wherein an axis (Y-Y’) passing through the cross-member (206) is offset to the axis (X-X’) passing through the pair of wheel hub connectors (202 and 204).
10. The drivetrain assembly (106) as claimed in claim 9, wherein at least one portion of the traction motor (104) passes through the axis (X-X’) passing through the pair of wheel hub connectors (202 and 204).
11. An electrical vehicle, comprising:
a drivetrain assembly (106), comprising:
a traction motor (104); and
an axle beam (124) comprising:
a pair of wheel hub connectors (202 and 204); and
a cross-member (206) formed between the pair of wheel hub connectors (202 and 204), wherein the cross-member (206) and the pair of wheel hub connectors (202 and 204) are formed as an open C-shaped channel, wherein the cross-member (206) is configured to face the traction motor (104), and the pair of wheel hub connectors (202 and 204) is configured to accommodate a pair of driveshafts (120 and 122) extending from the traction motor (104).
12. The electrical vehicle as claimed in claim 11, wherein the open C-shaped channel at the cross-member (206) is narrower than the open C-shaped channel at the pair of wheel hub connectors (202 and 204) by a predefined value.