Patent ID: 12202359

DETAILED DESCRIPTION

The following description relates to systems and methods for an electrified heavy-duty vehicle. In order to be electrically propelled, an electrical system of the vehicle may be adapted with a battery pack arranged along a chassis of the vehicle, as shown inFIG.1. In one example, the vehicle may be configured with a skateboard chassis where the battery is integrated into the skateboard chassis, as illustrated inFIG.2. An example of the battery pack is shown inFIG.3from a perspective view and depicted inFIG.4with an outer housing removed. A more detailed view of an internal structure of the battery pack is shown inFIG.5. The electrified vehicle may be adapted with front-wheel drive to accommodate a positioning of the battery pack in the vehicle while providing a desired traction and acceleration at the vehicle wheels. The vehicle may further be configured with regenerative braking to recharge the battery pack. As such, the front wheels may include drive shaft adapters which allow regenerative braking to be conducted at the front wheels. An example of a drive shaft adapter arranged in a wheel hub is illustrated inFIG.6, in a cut-away view. The drive shaft adapter is shown in greater detail inFIGS.7-9. To further accommodate placement of the battery pack in the vehicle, the vehicle may include a sub-system cradle, as shown in the examples ofFIGS.10-12B, the sub-system cradle configured to consolidate mounting of electrical sub-systems of the vehicle onto a single structure, thereby simplifying assembly and decreasing an overall footprint of the sub-systems. An exemplary configuration of the sub-system cradle within the vehicle is further depicted inFIGS.13and14.

FIGS.1-14show example configurations with relative positioning of the various components. If shown directly contacting each other, or directly coupled, then such elements may be referred to as directly contacting or directly coupled, respectively, at least in one example. Similarly, elements shown contiguous or adjacent to one another may be contiguous or adjacent to each other, respectively, at least in one example. As an example, components laying in face-sharing contact with each other may be referred to as in face-sharing contact. As another example, elements positioned apart from each other with only a space there-between and no other components may be referred to as such, in at least one example. As yet another example, elements shown above/below one another, at opposite sides to one another, or to the left/right of one another may be referred to as such, relative to one another. Further, as shown in the figures, a topmost element or point of element may be referred to as a “top” of the component and a bottommost element or point of the element may be referred to as a “bottom” of the component, in at least one example. As used herein, top/bottom, upper/lower, above/below, may be relative to a vertical axis of the figures and used to describe positioning of elements of the figures relative to one another. As such, elements shown above other elements are positioned vertically above the other elements, in one example. As yet another example, shapes of the elements depicted within the figures may be referred to as having those shapes (e.g., such as being circular, straight, planar, curved, rounded, chamfered, angled, or the like). Further, elements shown intersecting one another may be referred to as intersecting elements or intersecting one another, in at least one example. Further still, an element shown within another element or shown outside of another element may be referred as such, in one example.

Turning now toFIG.1, a heavy-duty vehicle100may have an electrical system configured with a battery pack102as a prime mover providing electrical energy for propulsion. A set of reference axes101are provided for comparison between views shown, indicating a y-axis, an x-axis, and a z-axis. In one example, the y-axis may be parallel with a direction of gravity and a vertical direction, the x-axis parallel with a horizontal direction, and the z-axis parallel with transverse direction and a longitudinal axis of the vehicle100, e.g., parallel with a length of the vehicle100. The heavy-duty vehicle100may be a variety of vehicle types, including light commercial vehicles, buses of different sizes, medium- and heavy-duty trucks, vocational vehicles, etc. The battery pack102may be an energy storage device configured to deliver electrical power to various components of the electrical system of the vehicle100including supplying current to motors coupled to front wheels104and/or rear wheels106of the vehicle100. The battery pack102may extend along a chassis108of the vehicle100, between the front wheels104and the rear wheels106, along a portion of a length110of the vehicle100. A width112of the battery pack102may be similar to a distance between innermost wheels of the rear wheels106.

In one example, the chassis108of the vehicle100may be a skateboard chassis108in which the battery pack102is integrated, e.g., forming a continuous unit with the skateboard chassis108. The skateboard chassis108may extend along a greater portion of the length110of the vehicle100than the battery pack102, from a point behind the front wheels104to a rear end116of the vehicle. However, in other examples, the skateboard chassis108may vary in length, e.g., the skateboard chassis108may be shorter than depicted inFIG.1. In one example, as shown in a profile view200of the vehicle100inFIG.2, the skateboard chassis108may be a platform forming a floor of the vehicle100. The skateboard chassis108may be formed of a solid, durable, strong material, such as aluminum, steel, fiber-reinforced materials, and/or other composite materials, able to withstand and support large loads (e.g., a maximum load for which the vehicle100is designed to carry under predetermined use cases or conditions).

The battery pack102may be embedded in the skateboard chassis108, e.g., enclosed in a recess in the skateboard chassis108, to form a single integrated structure, and may therefore also be incorporated into the floor of the vehicle100. A bottom face202of the battery pack102may form a portion of a bottom surface204of the skateboard chassis108. The battery pack102may therefore be biased within the skateboard chassis108at a lower region, with respect to the y-axis, of the skateboard chassis108. However, in other examples, the battery pack102may instead be biased at an upper region of the skateboard chassis108with an upper face206of the battery pack102forming a portion of an upper surface208of the skateboard chassis108. In yet other examples, the battery pack102may extend along a majority of a height210of the skateboard chassis108.

The skateboard chassis108may provide various benefits with respect to efficient assembly and packaging of the vehicle100. For example, the skateboard chassis108may be readily scalable, allowing different types of vehicle bodies to be attached. Depending on a height of a payload of the vehicle100, a low vertical (e.g., with respect to the y-axis) positioning of the battery pack102in the vehicle100may provide even and balanced weight distribution without adversely affecting, or even positively contributing to, a balance of the vehicle100. Furthermore, locating the battery pack102in the vehicle floor may increase cabin space while enclosing the battery pack102in a durable, rigid structure that supports and shields the battery pack102from contact with debris, moving vehicle components, etc.

Returning toFIG.1, a positioning of the battery pack102in the vehicle100may result in locating electrical components, such as electric motors, in a region between a front end114of the vehicle100and a front edge109of the skateboard chassis108. Thus, packaging space is available between the front wheels104, allowing implementation of a powertrain and a drive train at the front wheels104but not at the rear wheels106when the vehicle100is adapted with the skateboard chassis108.

In addition, the battery pack102itself may be a strong, rigid structure and incorporating the battery pack102into the skateboard chassis108may further increase an overall stiffness, torsional resistance, and bending resistance of the skateboard chassis108. By positioning the battery pack102at the bottom region of the skateboard chassis108, the battery pack may be easily accessible for maintenance and/or replacement. As such, the battery pack102may be removably coupled to the skateboard chassis108and configured as a frame integrated independent sub-structure in the skateboard chassis108. In other words, the battery pack102has a stand-alone structure that is embedded into the skateboard chassis108but readily accessible and may be removed when desired.

A perspective view300of the battery pack102is depicted inFIG.3. The battery pack has a top cover (not shown atFIG.3) and a bottom cover302, where the bottom cover302may form the bottom face202of the battery pack102and be included in the bottom surface204of the skateboard chassis108, as shown inFIG.2. Accordingly, the bottom cover302may be formed of a rigid, durable material, such as steel, aluminum, a composite, etc. The top cover may be disposed opposite to the bottom cover302along the y-axis. The top cover may be formed of a less rigid material than the bottom cover, such as molded plastic or another polymer, the top cover not being exposed to an exterior of the vehicle100. In other examples, the top cover may be formed of a same material as the bottom cover302.

Reinforcing rails304may extend along a length306of the battery pack102with braces308extending between each of the rails304and side edges310of the bottom cover302, at an angle relative to the reinforcing rails304. The bottom cover302may further include apertures312for receiving fasteners to secure the bottom cover302to the skateboard chassis, e.g., the skateboard chassis108ofFIGS.1and2. It will be appreciated that the bottom cover302illustrated inFIG.3is a non-limiting example. Other examples may include variations in mechanisms and structures for coupling the bottom cover302to the skateboard chassis, as well as modifications to a geometry and relative dimensions of the bottom cover302, without departing from the scope of the present disclosure.

The bottom cover302may provide a barrier between an internal structure of the battery pack102and external objects. The internal structure of the battery pack102may include a plurality of modules402, as shown in a bottom view400of the battery pack102with the top cover removed and in a detailed view inFIG.5of dashed area500. The plurality of modules402may be arranged in rows along the z-axis, spaced apart from adjacent rows. Each module of the plurality of modules402includes multiple cells404connected in series or parallel within the module402. The plurality of modules402may be connected in parallel and coupled to electrical terminals406of the battery pack.

The battery pack102may include other internal components, such as electrical interconnects, at least one contactor408, at least one pre-charge resistor410, solid-state relays (SSRs)412, and at least one current sensor414, in addition to at least one temperature sensor, at least one voltage sensor, at least one current sensor, a battery management system, contactors, pre-charge resistors, high- and low-voltage fuses, a resistive heating system, busbars, a cooling system, a connector and a 12V bus for supplying power to the various electronics, etc. The battery pack102may be configured with a slave-master battery management system with a manual service disconnect (MSD) (e.g., at the electrical terminals406), integrated heat pads, and pre-charge capability. The cells404may have various capacities and chemistries, and may be configured in any one of a number of series-parallel module configurations.

As described above, by adapting the vehicle with the skateboard chassis and integrated battery pack, additional components of the vehicle's electrical system, such as electric motors, may be positioned around the skateboard chassis, along a similar horizontal plane as the skateboard chassis. For example, an electric motor and a drive train may be arranged in front of the skateboard chassis, e.g., between the front end114of the vehicle100and a front edge109of the skateboard chassis108ofFIG.1, and between the front wheels104. As such, the vehicle may be configured with front-wheel drive, as shown inFIG.1. The vehicle100includes a motor118arranged proximate to the front end114of the vehicle100, between the front wheels104, the motor118configured to receive electrical power from the battery pack102. In one example, the motor118may be a motor/generator, able to convert mechanical energy to electrical energy to recharge the battery pack102. The motor118may be coupled to a drive train120which, in turn, is coupled to drive shafts122of the front wheels104. The drive train120may include components such as a transmission and a differential. A torque converter may be located between the motor118and the transmission if the transmission is automatic, or a clutch may be arranged between the motor118and the transmission if the transmission is manual or single-gear direct drive. Thus, electrical power drawn from the battery pack102by the motor118may be converted to torque to drive rotation of the front wheels104via the drive train120. The rear wheels106may be trailer wheels rotated together on a single axle152.

Implementing regenerative braking in the vehicle100may increase an efficiency and appeal of the vehicle100by allowing energy that may otherwise be lost as waste heat to be at least partially recuperated. The recovered energy may be used to replenish battery charge with the motor118operating as a generator in such instances. However, conventional front wheel hub assemblies124compatible with motorized front wheels104, such as front wheel hub assemblies used in heavy-duty vehicles configured with four-wheel drive, may not be suitable for regenerative braking due to an automatic locking mechanism of the conventional front wheel hub assemblies. The use of front wheel hub assemblies with automatic locking mechanisms may disrupt regenerative braking. For example, the automatic locking mechanism of a given front wheel hub assembly may correspond to a ratchet mechanism. Specifically, the automatic locking mechanism may allow a corresponding front wheel104to rotate freely about its drive shaft122when no torque is applied, impeding regenerative braking by allowing free rotation of the front wheel104absent applied acceleration torque (which in turn may not brake the vehicle100). Instead, regenerative braking is typically made possible via a rigid connection between the drive shafts and the wheels, such that when deceleration (braking) torque is applied, the wheels will not rotate freely and kinetic energy of the vehicle100may be converted back to electrical energy. As an alternative, customized front wheel hub assemblies adapted for regenerative braking may be manufactured. However, such customized front wheel hub assemblies may be undesirable due to a high cost of production.

One approach to address the issue described above includes replacing the automatic locking mechanism of the conventional front wheel hub assemblies124with a drive shaft adapter126, as indicated inFIG.1, that enables regenerative braking to occur at the vehicle front wheels104. As such, the conventional front wheel hub assemblies may be used, e.g., as used for four-wheel drive applications, circumventing additional costs arising from development of customized components, and adapted to assist in converting kinetic energy of the vehicle into energy stored at the battery pack102. The drive shaft adapter126may be directly coupled to each of the front wheel hub assemblies124, in contact with the drive shafts122of the front wheels104. An example of one of the drive shaft adapters126is illustrated inFIG.6, enclosed within one of the front wheel hub assemblies124, from a cut-away view600.

The front wheel hub assembly124may extend through a central region of one of the front wheels104such that at least a portion of the front wheel hub assembly124is circumferentially surrounded by the front wheel104. The front wheel hub assembly124may be formed of a durable, rigid material, such as steel or aluminum and may include a wheel cover602, a wheel bearing604, amongst other components. The front wheel hub assembly124may have a central opening606in which the wheel bearing604is located. The wheel bearing604may similarly have a central opening608through which the drive shaft adapter126is inserted.

The drive shaft adapter126may be circumferentially surrounded by the wheel bearing604and in direct contact with the wheel bearing604. The drive shaft adapter126may extend along the x-axis, centered about a central axis610of the front wheel hub assembly124. A length612, as defined along the x-axis, of the drive shaft adapter126may be similar to a width, also defined along the x-axis, of the front wheel hub assembly124. The drive shaft adapter126may be a hollow, tubular structure with an inner passage614configured to receive a drive shaft, such as one of the drive shafts122ofFIG.1. The drive shaft adapter126may couple with the drive shaft and the wheel bearing604so that rotation of the drive shaft compels rotation of the drive shaft adapter and the wheel bearing604in unison with the drive shaft. The rotation of the wheel bearing604thereby drives rotation of remaining components of the front wheel hub assembly124and the front wheel104, also in unison with the drive shaft.

The drive shaft adapter126is shown without the front wheel hub assembly124inFIGS.7-9from a perspective view700, a profile view800, and a cut-away view900, respectively. The drive shaft adapter126may have a first portion702continuous with a second portion704. The first portion702may form a greater portion of the length612of the drive shaft adapter126than the second portion704. An outer diameter of the first portion702of the drive shaft adapter126may vary with a length of the first portion702. For example, the first portion702may include a first section802adjacent to and contiguous with the second portion704of the drive shaft adapter126, the first section802having a uniform outer diameter801, as shown inFIG.8. The first portion702may also have a second section804with a tapering outer diameter, e.g., the outer diameter of the second section804decreases from the first section802to a third section806of the first portion702of the drive shaft adapter126. The first portion702may further include the third section806having a uniform outer diameter803that is narrower than the first section802. While the outer diameter of the first portion702of the drive shaft adapter126is not uniform, an overall change in the outer diameter is less than an overall change in an outer diameter of the second portion704of the drive shaft adapter126, as described further below.

An inner diameter902, as shown inFIG.9, of the first portion702(and of the inner passage614of the drive shaft adapter126) may be uniform along most of the length of the first portion702except for a flared end904of the first portion702, enclosed within the third section806of the first portion702, where the inner diameter902increases. The inner diameter902of the first portion702may be similar to an outer diameter of a drive shaft, adapted to fit tightly around an end of the drive shaft so that the drive shaft and the drive shaft adapter126rotate in unison, e.g., the drive shaft does not rotate relative to the drive shaft adapter126. The drive shaft adapter126may be coupled to the drive shaft via a press fit connection, by welding, via a fastening mechanism, and/or by a male-female mating configuration. In one example, the coupling of the drive shaft adapter126to the drive shaft may be permanent, e.g., the drive shaft adapter126and the end of the drive shaft may not be detached from one another once coupled.

For example, the drive shaft adapter126may include a plurality of male splines708on an outer surface710of the first portion702. As shown, the plurality of male splines708may be substantially evenly spaced around a circumference of the first portion702, and may extend along at least a portion of the outer surface710of the first portion702along the x-axis. A plurality of female splines (not shown atFIGS.6-9) may be correspondingly disposed on an inner surface of the wheel bearing604. The drive shaft adapter126may be press fit into the central opening608of the wheel bearing604such that the plurality of male splines708may respectively mate with the plurality of female splines. The inner passage614of the drive shaft adapter126may be loose fit to a spline of the drive shaft122(not shown atFIGS.6-9) to form a constant-velocity (CV) joint. The drive shaft adapter126may be fixed to the drive shaft122via a nut (not shown atFIGS.6-9) fastened on threads of an end of the drive shaft122, the nut torqued to an inner surface814of the first section802. A flange (e.g., third section812, as described below) of the second portion704may be directly coupled and fastened to the wheel bearing604via a plurality of fasteners, such as bolts, respectively fit into a plurality of fastener holes706. The second portion704of the drive shaft adapter126includes a first section808with a uniform outer diameter805, as shown inFIG.8, where the first section808is contiguous with the first section802of the first portion702of the drive shaft adapter126. A second section810of the second portion704, the second section810having a tapering outer diameter that increases from the first section808to the third section812of the second portion704, is contiguous with the first section808. The third section812of the second portion704of the drive shaft adapter126is contiguous with the second section810and may be a flange812with an outer diameter807forming a widest section, with respect to the y-axis, of the drive shaft adapter126.

As illustrated inFIG.9, an inner diameter906of the first section808and a part of the second section810of the second portion704of the drive shaft adapter126may be uniform along a length, as defined along the x-axis, of the second portion704. Within the second section810and the flange812of the second portion704, the inner diameter of the second portion increases along a direction from the second section810to the flange812. The inner passage614of the drive shaft adapter126at the second portion704of the drive shaft adapter126may be configured to receive each of a CV joint nut and a hubcap. As shown inFIG.6, the flange812of the drive shaft adapter126may be shaped to interface with both the wheel bearing604and the wheel cover602of the front wheel hub assembly124. The flange812may include the plurality of fastener holes706, as shown inFIGS.7and9, to enable the drive shaft adapter126to be secured to the front wheel hub assembly124with fasteners, such as bolts. As such, the drive shaft adapter126may be connected to the wheel bearing604via a combination of the fasteners and a press-fit connection, resulting in the drive shaft, the drive shaft adapter126, and the front wheel hub assembly124rotating in unison around the central axis610when compelled to turn by a motor. In other words, the drive shaft adapter126does not rotate relative to the drive shaft or the front wheel hub assembly124.

Implementing front-wheel drive in the heavy-duty vehicle while maintaining use of the automatic locking hubs may impose undesirable power draw from a battery of the vehicle. Furthermore, the automatic locking hubs may not be compatible with regenerative braking, thus inhibiting recovery of energy generated during vehicle speed reduction. By replacing the automatic locking hubs with the drive shaft adapter shown inFIGS.6-9, the front wheel hub assemblies may be fixedly coupled (e.g., the drive shaft adapter does not disengage from the front drive shaft) to the front drive shafts. Regenerative braking is thereby enabled at the vehicle front wheels. By replacing the automatic locking hubs with the drive shaft adapter without demanding further modifications to the front wheel hub assemblies (e.g., modifications to the wheel cover, the wheel bearing, and other components of the front wheel hub assemblies not directly interfacing with the drive shaft), increases in a cost of the front wheel hub assemblies may be circumvented while providing efficient energy recovery.

As described above, implementation of a drive shaft adapter may accommodate a front-wheel drive configuration of an electrified heavy-duty vehicle adapted with a skateboard chassis with an integrated battery pack. Packaging constraints imposed by the skateboard chassis may also demand rearrangement of power electronics of various vehicle electrical sub-systems such as a hydraulic pump, an air pump, an air conditioning (A/C) compressor, a water pump, controllers, junction boxes, fuses, a battery charger, inverters, etc., due to a vertically low positioning of the skateboard chassis. The sub-systems are included in an electrical system of the vehicle, drawing power from the battery pack. For example, as illustrated inFIG.1, incorporation of the battery pack102into the skateboard chassis108may demand positioning sub-systems power electronics in a region between the front edge109of the skateboard chassis108and the front end114of the vehicle100where various other vehicle components already occupy at least a portion of the available packaging space. Positioning the power electronics of each of the sub-systems wherever each sub-system may be accommodated may result in use of long connectors, wires, and electrical cables which may be directly coupled to a frame of the vehicle100to maintain the connectors, wires, and cables off the ground. The connectors, wires, and cables may become easily tangled, degraded, and/or disconnected or come into contact with moving components of the vehicle100. In addition, a scattered arrangement of the sub-systems may complicate access to components of the sub-systems when maintenance and repair is demanded.

Furthermore, during assembly, individual coupling of the sub-systems to the vehicle frame may be time consuming and include complex routing and tethering of connectors, wires, and cables. Sub-system components, such as pumps, may demand installation of rubber mounts to dampen transmission of vibrations to the vehicle chassis, which increases a number of parts to be attached to the vehicle and further adds to assembly time. In addition, individual coupling of the sub-systems may result in the sub-systems having an undesirably large footprint.

An overall footprint of the sub-systems power electronics may be reduced by mounting the power electronics on a single cradle. The cradle may be a supporting structure onto which the power electronics may be attached, thus consolidating the power electronics into a single unit. The power electronics may be assembled in the cradle prior to coupling to the vehicle. Electrical cables, vibrating components such as pumps, etc., may be secured to the cradle rather than individually attached to the vehicle frame and the cradle, supporting sub-systems relying on power from the battery pack, may be mounted to the vehicle frame in a position that allows convenient electrical coupling of the sub-systems to the battery pack. In some examples, the power electronics may be attached to the cradle without rubber supports. Instead, the cradle may be mounted to the vehicle chassis on rubber supports to reduce transmission of vibrations to the vehicle from the sub-systems power electronics as a single unit, thereby decreasing an amount of rubber supports for suppressing propagation of vibrations.

As described above, a cradle may provide consolidation of power electronics for various electrical sub-systems of a vehicle, thus decreasing an overall footprint of the sub-systems. The cradle may be positioned in an accessible location along the vehicle frame, around the skateboard chassis and proximate to the battery pack102to enable electrical coupling of the sub-systems to the battery pack102without use of undesirably long cables. For example, as shown inFIG.1, a cradle150may be positioned along an underside160of the vehicle100, between the front end114and the skateboard chassis108, along a driver's side of the vehicle100. However, other examples may include the cradle150arranged in other locations along the vehicle frame, similarly between the front end114and the skateboard chassis108(such as on a passenger's side of the vehicle100or taking the place of an internal combustion engine, e.g., in front of the vehicle cabin). Accordingly, the cradle150may be placed for ease of access for maintenance thereof.

The power electronics mounted on the cradle150may include various sub-system controllers. The controllers may be communicatively coupled to a vehicle control unit130, such as powertrain control module. The control unit130is a computing device, such as a microcomputer that includes a processor unit, a non-transitory computer-readable storage medium device, input/output ports, memory, and a data bus. Computer-readable storage medium included in the control unit130is programmable with computer readable data representing instructions executable by the processor for performing various control routines and methods. Operation of the various sub-systems supported on the cradle150may be controlled by the control unit130, based on various sensors and actuators (not shown) included in the vehicle100.

A first example of a cradle1000for supporting power electronics of vehicle sub-systems is shown in perspective view1025ofFIG.10. The cradle1000includes a frame1002formed of a rigid, durable material, such as aluminum, steel (e.g., A36 steel), casted metal, etc. The frame1002has a first compartment1004stacked over a second compartment1006, along the y-axis, with a floor1008extending along the x-z plane therebetween and dividing the first compartment1004from the second compartment1006. Various sub-system components may be directly attached to the frame1002of the cradle1000and/or within one or more of the first compartment1004and the second compartment1006. For example, the sub-system components may be enclosed within each of the first compartment1004and the second compartment1006and also coupled to external surfaces1001of the frame1002. The sub-system components may include one or more of electrohydraulic brake and electrohydraulic power steering pumps1010, a heating, ventilation, and air-conditioning (HVAC) or air-conditioning (A/C) compressor1012, one or more controllers1014, one or more low-voltage fuse (e.g., 12V) boxes1016, and one or more high-voltage coolant pumps1018, in addition to other high-voltage power electronics including one or more of accessory inverters, high-voltage battery chargers, high-voltage motor inverters, high-voltage DCDC units, etc. It will be appreciated that at least some sub-system components, such as the low-voltage fuse boxes1016, may be positioned for ease of access for maintenance.

Electrical cables, wires, as well as connectors such as pump hoses, tubing, etc., of the sub-system components may be directly coupled to the cradle1000before the cradle1000is attached to a vehicle. For example, the sub-system components may be mounted onto the cradle at a manufacturing facility. The assembled cradle1000may then be secured to a frame of the vehicle via fastening devices such as bolts or by other mechanical fastening methods. In some examples, the cradle1000may be removably coupled to the vehicle frame to allow detachment of the cradle1000when maintenance and/or inspection of the sub-system components is desired. Furthermore, rubber supports may be positioned between the cradle1000and the vehicle frame to absorb vibrations generated during operation of the sub-system components, such as the pumps1010and the compressor1012.

A second example of a cradle1100for supporting power electronics of vehicle sub-systems is shown in perspective view1125, perspective view1175, exploded view1225, and exploded view1275ofFIGS.11A-12B, respectively. It will be appreciated that features of the second example ofFIGS.11A-12Bmay be embodiments of similarly labeled features of the first example ofFIG.10. For example, the frame1102may be an embodiment of the frame1002.

The cradle1100includes a frame1102formed of a rigid, durable material, such as aluminum, steel (e.g., A36 steel), casted metal, etc. Though, the frame1102may be opaque in practice, the frame1102is depicted as transparent inFIGS.11A-12Bso as not to obscure the various components included therein. The frame1102has a first compartment1104stacked over a second compartment1106, along the y-axis, with a floor1108extending along the x-z plane therebetween and dividing the first compartment1104from the second compartment1106. A cavity1103may further be stacked over the first comportment1104, along the y-axis. Various sub-system components may be directly attached to the frame1102of the cradle1100and/or within one or more of the cavity1103, the first compartment1104, and the second compartment1106. For example, the sub-system components may be enclosed within each of the cavity1103, the first compartment1104, and the second compartment1106and also coupled to external surfaces of the frame1102. The sub-system components may include one or more of electrohydraulic brake and electrohydraulic power steering pumps1110(a single electrohydraulic power steering pump1110coupled to an inverter1132therefor being depicted in the second example ofFIGS.11A-12B), an HVAC or A/C compressor1112, one or more controllers1114, one or more low-voltage (e.g., 12V) fuse boxes1116, a multiplex power distribution module (MPDM)1120, a junction box1122, one or more low-voltage (e.g., 12V) contactors1126, a cabin heater unit1130, and an electric power takeoff (ePTO) system1136(not shown inFIGS.11A and11Bso as not to obscure other components of the second compartment1106) in addition to other high-voltage power electronics including one or more of accessory inverters (e.g., inverter1130), high-voltage battery chargers1128, high-voltage motor inverters1124, high-voltage DCDC units1134, high-voltage coolant pumps, etc. It will be appreciated that at least some sub-system components, such as the low-voltage fuse boxes1116, may be positioned for ease of access for maintenance.

Electrical cables, wires, as well as connectors such as pump hoses, tubing, etc., of the sub-system components may be directly coupled to the cradle1100before the cradle1100is attached to a vehicle. For example, the sub-system components may be mounted onto the cradle at a manufacturing facility. The assembled cradle1100may then be secured to a frame of the vehicle via fastening devices such as bolts or by other mechanical fastening methods. In some examples, the cradle1100may be removably coupled to the vehicle frame to allow detachment of the cradle1100when maintenance and/or inspection of the sub-system components is desired. Furthermore, rubber supports may be positioned between the cradle1100and the vehicle frame to absorb vibrations generated during operation of the sub-system components, such as the pumps1110and the compressor1112.

The cradle of the present disclosure may be positioned in various locations of the vehicle relative to the chassis having the battery pack. For example, the cradle may be positioned in front of the chassis at the driver's side, the passenger's side, or therebetween (e.g., taking the place of an internal combustion engine). In other examples, and as depicted in perspective view1300and cross section1400ofFIGS.13and14, respectively, the cradle, such as the cradle150, may be positioned above an axle along the y-axis, such as the rear axle152, between an innermost pair of wheels along the x-axis, such as between the innermost pair of the rear wheels106. Specifically, the cradle150may account for the skateboard chassis108by being positioned adjacent to and at least partially within the skateboard chassis108, e.g., above an upper surface (e.g.,208) of the skateboard chassis108along the y-axis, supported between and affixed to rails1302of the skateboard chassis108(as shown inFIGS.13and14). It will be appreciated that each component of the vehicle is not depicted inFIGS.13and14so as not to obscure positioning of the cradle150.

In this way, a heavy-duty vehicle may be electrified, powered by a battery pack integrated into a chassis of the vehicle where the chassis forms a floor of the vehicle. The integrated battery pack may be embedded into the chassis, reinforcing a structural integrity of the chassis, and configured to be removable to allow the battery pack to be readily inspected and/or removed. The vehicle may be adapted with front-wheel drive to accommodate a low vertical positioning of the chassis and battery pack. Front-wheel drive in the vehicle may be implemented at low cost by utilizing conventional wheel hub assemblies and coupling the wheel hub assemblies to front drive shafts of the vehicle via drive shaft adapters. The drive shaft adapters may replace automatic locking hubs, thereby permanently coupling to the front drive shafts and enabling regenerative braking to be implemented at the vehicle front wheels. Constraints on packaging space for power electronics of vehicle sub-systems imposed by the vehicle chassis and battery pack may be accommodated by mounting the power electronics onto a single cradle, thereby providing a compact arrangement of the sub-systems at a single location. Mounting the power electronics of the sub-systems onto the cradle may also allow the sub-systems to be located close to the battery pack from which the sub-systems may draw electrical power. The cradle may be pre-assembled, reducing an amount of time spent on coupling the sub-systems to the vehicle. Components and accessories of the power electronics, such as electrical cables, wires, etc., may be attached to the cradle instead of the vehicle frame, reducing a likelihood of entanglement and/or detachment. The cradle may be mounted to the vehicle frame with rubber supports to inhibit transmission of vibrations from the sub-systems to the vehicle frame, thereby suppressing transfer of vibrational energy at a single contact point, rather than at multiple connection points when the sub-systems are individually coupled to the vehicle frame. As a result, electrification of the heavy-duty vehicle is enabled at low cost and high efficiency with rapid assembly time.

The disclosure also provides support for an electric vehicle, comprising: a battery pack for supplying current to an electric motor of the electric vehicle, the battery pack arranged in a chassis of the electric vehicle and configured to form part of a floor of the electric vehicle, a motor arranged adjacent to the chassis and coupled to front wheels of the electric vehicle, the front wheels having hub assemblies housing drive shaft adapters, wherein the drive shaft adapters are configured to permanently couple the hub assemblies to drive shafts of the front wheels, and a cradle positioned adjacent to the chassis along a frame of the electric vehicle, the cradle configured to be mounted with electrical sub-systems of the electric vehicle. In a first example of the system, the battery pack is embedded in the chassis and a cover of the battery pack forms a portion of a surface of the chassis and wherein the chassis forms the floor of the electric vehicle. In a second example of the system, optionally including the first example, the battery pack is removably arranged in the chassis of the electric vehicle and the chassis is a skateboard chassis with a low vertical positioning in the electric vehicle. In a third example of the system, optionally including the first and second examples, the battery pack has a sub-structure independent of the chassis and includes at least one of a slave-master battery management system, connectors resistant to multiple spark discharge, pre-charge capability, and integrated heat pads. In a fourth example of the system, optionally including the first through third examples, the chassis extends from behind the front wheels to a rear end of the electric vehicle and wherein the battery pack is arranged in the chassis in a region between the front wheels and rear wheels of the electric vehicle. In a fifth example of the system, optionally including the first through fourth examples, the drive shaft adapters extend through a central opening of each of the hub assemblies and do not rotate relative to the hub assemblies. In a sixth example of the system, optionally including the first through fifth examples, the drive shaft adapters are configured to receive ends of the drive shafts in an inner passage of each of the drive shaft adapters. In a seventh example of the system, optionally including the first through sixth examples, the drive shaft adapters circumferentially surround the ends of the drive shafts and form a constant-velocity joint with the drive shafts. In an eighth example of the system, optionally including the first through seventh examples, the cradle is attached to the frame of the electric vehicle with a rubber support arranged in between, the rubber support configured to suppress transmission of vibrations. In a ninth example of the system, optionally including the first through eighth examples, the cradle has one or more compartments configured to house the electrical sub-systems and wherein the electrical sub-systems are directly coupled to a structure of the cradle and not the frame of the electric vehicle.

The disclosure also provides support for an electrical system of a heavy-duty vehicle, comprising: a battery pack embedded in a chassis of the vehicle, the chassis forming a floor of the vehicle, and a plurality of sub-system power electronics electrically coupled to the battery pack and mounted to a cradle. In a first example of the system, the cradle is positioned along a common horizontal plane as the chassis and arranged in a region along an underside of the vehicle between a front edge of the chassis and a front end of the vehicle. In a second example of the system, optionally including the first example, the cradle has a frame formed of a rigid, durable material and wherein the plurality of sub-system power electronics is directly attached to the frame of the cradle. In a third example of the system, optionally including the first and second examples, the frame of the cradle includes a first compartment stacked vertically over a second compartment and each of the first compartment and the second compartment are configured to enclose one or more of the plurality of sub-system power electronics. In a fourth example of the system, optionally including the first through third examples, one or more of the plurality of sub-system power electronics are coupled to external surfaces of the frame of the cradle. In a fifth example of the system, optionally including the first through fourth examples, the plurality of sub-system power electronics includes one or more of an inverter, a battery charger, a controller, a pump, an air conditioning compressor, a junction box, and a fuse.

The disclosure also provides support for an electric vehicle, comprising: a battery pack embedded in a chassis of the vehicle, the chassis forming a floor of the vehicle, and a motor arranged in front of the chassis and between front wheels of the vehicle, the motor driving rotation of the front wheels, wherein the front wheels have wheel hub assemblies housing drive shaft adapters configured to couple to drive shafts of the front wheels. In a first example of the system, the drive shaft adapters are arranged between ends of the drive shafts and the wheel hub assemblies, within central openings of the wheel hub assemblies, and wherein the wheel hub assemblies are four-wheel drive wheel hub assemblies. In a second example of the system, optionally including the first example, the drive shaft adapters have a first portion with a first inner diameter contiguous with a second portion with a second, larger inner diameter and wherein the first portion is configured to receive the ends of the drive shafts and the second portion is configured to interface with a wheel cover and a wheel bearing of the wheel hub assemblies. In a third example of the system, optionally including the first and second examples, the wheel hub assemblies with the drive shaft adapters are configured to be compatible with regenerative braking.

In another representation, an electric vehicle includes a battery pack embedded into a chassis of the vehicle, the battery pack forming a portion of a floor of the vehicle. In a first example of the electric vehicle, the battery pack is arranged in a recess of the chassis and forms a continuous unit with the chassis. A second example of the electric vehicle optionally includes the first example, and further includes, wherein the chassis forms the floor of the vehicle and extends from behind front wheels of the vehicle to a rear end of the vehicle and wherein a length and a width of the battery pack is less than a length and a width of the chassis. A third example of the electric vehicle optionally includes one or more of the first and second examples, and further includes, wherein the battery pack is biased towards a lower portion of the chassis and a removable cover of the battery forms a portion of a bottom surface of the chassis. A fourth example of the electric vehicle optionally includes one or more of the first through third examples, and further includes, wherein the removable cover includes reinforcing rails and braces extending between the rails and side edges of the removable cover. A fifth example of the electric vehicle optionally includes one or more of the first through fourth examples, and further includes, wherein the battery pack is configured to be removable from the chassis. A sixth example of the electric vehicle optionally includes one or more of the first through fifth examples, and further includes, wherein the removable cover has a plurality of apertures for receiving fasteners.

In another representation, an electric vehicle includes a drive shaft adapter positioned between a front drive shaft and a front wheel hub assembly of the vehicle, the drive shaft adapter configured to permanently couple to the front drive shaft. In a first example of the electric vehicle, the drive shaft adapter has a tubular structure with an inner passage aligned with a central axis of rotation of the front wheel hub assembly. A second example of the electric vehicle optionally includes the first example, and further includes, wherein the drive shaft adapter has a first portion contiguous with a second portion along a length of the drive shaft adapter and wherein the first portion has a smaller inner diameter than the second portion. A third example of the electric vehicle optionally includes one or more of the first and second examples, and further includes, wherein the inner diameter of the first portion of the drive shaft adapter is similar to an outer diameter of the front drive shaft and the first portion of the drive shaft adapter is configured circumferentially surround an end of the drive shaft adapter. A fourth example of the electric vehicle optionally includes one or more of the first through third examples, and further includes, wherein the second portion of the drive shaft adapter has a flange with fastener openings and wherein the flange is coupled to a wheel bearing of the front wheel hub assembly via a combination of a press-fit connection and fasteners inserted through the fastener openings. A fifth example of the electric vehicle optionally includes one or more of the first through fourth examples, and further includes, wherein the drive shaft adapter is in direct contact with the wheel bearing of the front wheel hub assembly and the drive shaft adapter does not rotate relative to the front wheel hub assembly. A sixth example of the electric vehicle optionally includes one or more of the first through fifth examples, and further includes, wherein the drive shaft adapter, the drive shaft, and the front wheel hub assembly rotate in unison.

In yet another representation, an electric vehicle includes a plurality of sub-system power electronics mounted to a cradle, where the cradle is coupled to a frame of the vehicle between a front end of the vehicle and a chassis of the vehicle. In a first example of the electric vehicle, the cradle has a frame formed of a rigid, durable material. A second example of the electric vehicle optionally includes the first example, and further includes, wherein the plurality of sub-system power electronics is attached to the frame of the cradle without rubber supports in between. A third example of the electric vehicle optionally includes one or more of the first and second examples, and further includes, wherein the plurality of sub-system power electronics are electrically coupled to a battery pack of the vehicle via electrical cables. A fourth example of the electric vehicle optionally includes one or more of the first through third examples, and further includes, wherein the electrical cables and other connectors of the plurality of sub-system power electronics are coupled to the frame of the cradle and not to the frame of the vehicle. A fifth example of the electric vehicle optionally includes one or more of the first through fourth examples, and further includes, wherein the plurality of sub-system power electronics includes controllers communicatively coupled to a control unit of the vehicle.

The following claims particularly point out certain combinations and sub-combinations regarded as novel and non-obvious. These claims may refer to “an” element or “a first” element or the equivalent thereof. Such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and sub-combinations of the disclosed features, functions, elements, and/or properties may be claimed through amendment of the present claims or through presentation of new claims in this or a related application. Such claims, whether broader, narrower, equal, or different in scope to the original claims, also are regarded as included within the subject matter of the present disclosure.