Powertrain, Vehicle, and Method With Electric Motors and Dual Belt Drive

FIELD OF THE INVENTION

p-0002This Invention relates to vehicles that have wheels powered by electric motors and powertrains for such vehicles, and belt drives for vehicles.

BACKGROUND OF THE INVENTION

p-0003Various powered vehicles have been used to transport passengers and cargo. Internal combustion engines have been used to power motor vehicles. In addition, electric motors have been used to drive wheels of vehicles, for example, powered by batteries, a generator located on the vehicle, or an external source of electricity. Examples include trains, golf carts, electric highway vehicles, and hybrid electric vehicles. Moreover, belts have been used to transfer power to auxiliary systems on motor vehicles and cogged belts have been used to turn cam shafts. Cogged belts have also been used to drive the rear wheel of motorcycles, and belts have been driven by electric motors and used to drive the wheels of wheelchairs. In addition, a number of types of transmission systems have been used to transmit torque and power from an electric motor to a wheel of a vehicle. As examples, electric motors have been rotatably attached directly to a wheel, have been rotatably attached using an axle with universal joints, have been connected to two wheels through a differential, and have been connected in driving relation through a gear box that provides speed reduction, and have been rotatably connected with a drive belt.

p-0004Needs and potential for benefit exist, however, for new and improved ways to transmit the torque and power of electric motors to the wheels of the vehicles. For example, needs or potential for benefit exist for electric motor powertrains for vehicles that are light weight, quiet, durable, inexpensive, easy to maintain, easy to design, that do not require a sealed gearbox containing gear oil, that provide speed reduction, that provide for independent control of torque transmission to two wheels on opposite sides of the vehicle, or a combination thereof, as examples. Further, needs or potential for benefit exist for vehicles having such drivetrains and for methods of manufacturing such powertrains and vehicles. Even further, needs or potential for benefit exist for such powertrains in highway vehicles including hybrid electric vehicles, fully electric vehicles, and all-wheel drive vehicles.

p-0005Other needs or potential for benefit or improvement may also be described herein or known in the automotive industry. Room for improvement exists over the prior art in these and other areas that may be apparent to a person of ordinary skill in the art having studied this document.

BRIEF DESCRIPTION OF THE DRAWINGS

p-0006<figref idrefs="DRAWINGS">FIG. 1</figref> is an isometric view of a highway vehicle having a dual belt drive transmission driving two wheels, with various components omitted for clarity;

p-0007<figref idrefs="DRAWINGS">FIG. 2</figref> is an isometric view of an electric vehicle powertrain (e.g., for the vehicle shown in <figref idrefs="DRAWINGS">FIG. 1</figref>) having two electric motors and a dual belt drive transmission driving two drive shafts;

p-0008<figref idrefs="DRAWINGS">FIG. 3</figref> is an isometric view of the dual belt drive transmission of the electric vehicle powertrain of <figref idrefs="DRAWINGS">FIG. 2</figref> (e.g., for the vehicle shown in <figref idrefs="DRAWINGS">FIG. 1</figref>), which has been turned upside down, having various components omitted for clarity;

p-0009<figref idrefs="DRAWINGS">FIG. 4</figref> is an isometric view of the dual belt drive transmission of the electric vehicle powertrain of <figref idrefs="DRAWINGS">FIG. 2</figref> (e.g., for the vehicle shown in <figref idrefs="DRAWINGS">FIG. 1</figref>) having various components omitted for clarity including the transmission housing;

p-0010<figref idrefs="DRAWINGS">FIG. 5</figref> is a right side cross sectional view of the dual belt drive transmission of <figref idrefs="DRAWINGS">FIGS. 3 and 4</figref> taken just right of the central wall;

p-0011<figref idrefs="DRAWINGS">FIG. 6</figref> is a right side cross sectional view of the dual belt drive transmission of <figref idrefs="DRAWINGS">FIGS. 3 and 4</figref> taken just left of the central wall;

p-0012<figref idrefs="DRAWINGS">FIG. 7</figref> is a top cross sectional view of the dual belt drive transmission of <figref idrefs="DRAWINGS">FIGS. 3 and 4</figref> taken through the center of the drive pulleys and the center of the driven pulleys;

p-0013<figref idrefs="DRAWINGS">FIG. 8</figref> is a front cross sectional view of the dual belt drive transmission of <figref idrefs="DRAWINGS">FIGS. 3 and 4</figref> taken through the centerline of the driven pulleys;

p-0014<figref idrefs="DRAWINGS">FIG. 9</figref> is a right side view of the right side wall of the dual belt drive transmission of <figref idrefs="DRAWINGS">FIGS. 3 and 4</figref>; and

p-0015<figref idrefs="DRAWINGS">FIG. 10</figref> is a flow chart illustrating, among other things, an example of a method of manufacturing a vehicle, for instance, having a dual belt drive.

p-0016These drawings illustrate, among other things, examples of embodiments of the invention. Other embodiments may differ.

SUMMARY OF PARTICULAR EMBODIMENTS OF THE INVENTION

p-0017This invention provides, among other things, various electric vehicle powertrains, highway vehicles, and methods of manufacturing vehicles, as examples. A number of embodiments include two belts, pulleys for each belt, an electric motor driving each drive pulley, a housing containing the belts and pulleys, and drive shafts (e.g., for driving the wheels of the vehicle), for instance. In various embodiments, the belts provide speed reduction, each motor drives one wheel independently from the other wheels, or both, for example. Particular aspects and configurations are novel and beneficial over prior technology.

p-0018Various embodiments provide, for example, as an object or benefit, that they partially or fully address or satisfy one or more needs, potential areas for benefit, or opportunities for improvement described herein, or known in the art, as examples. Certain embodiments provide, for example, improved equipment, apparatuses, and methods that transmit the torque and power of electric motors to the wheels of the vehicles. For example, particular embodiments are, include, or concern electric motor powertrains for vehicles. Various embodiments provide, for example, as an object or benefit, that the powertrain is light weight, quiet, durable, inexpensive, easy to maintain, easy to design, predictable in performance, or a combination thereof, as examples. Certain embodiments do not require a sealed gearbox containing gear oil, provide speed reduction, provide for independent control of torque transmission to two wheels on opposite sides of the vehicle, or a combination thereof, for instance. Further, objects or benefits of particular embodiments include providing vehicles having such drivetrains or methods of manufacturing such powertrains and vehicles. In some embodiments, such powertrains may be used in highway vehicles which may be hybrid electric vehicles, fully electric vehicles, or all-wheel drive vehicles, as examples.

p-0019Specific embodiments of the invention include various electric vehicle powertrains, for example. Such a powertrain may include a housing, for example, having a left wall and a right wall. The left wall may have an inboard side facing the right wall and an outboard side facing away from the right wall, and the right wall may have an inboard side facing the left wall and an outboard side facing away from the left wall, for example. In a number of embodiments, the left wall and the right wall each have a motor shaft relief and a drive shaft relief, for instance. Various embodiments further include a left electric motor mounted on the outboard side of the left wall at the motor shaft relief in the left wall and having a rotatable motor shaft, and a right electric motor mounted on the outboard side of the right wall at the motor shaft relief in the right wall, also having a rotatable motor shaft.

p-0020A number of such embodiments further include a left drive pulley located on the inboard side of the left wall and rotatably attached to the rotatable motor shaft of the left motor through the motor shaft relief in the left wall, and a right drive pulley located on the inboard side of the right wall and rotatably attached to the rotatable motor shaft of the right motor through the motor shaft relief in the right wall, for example. Moreover, a number of embodiments include a left driven pulley located on the inboard side of the left wall at the drive shaft relief in the left wall, and a right driven pulley located on the inboard side of the right wall at the drive shaft relief in the right wall, for instance.

p-0021Various such embodiments may also include a left drive shaft rotatably attached to the left driven pulley through the drive shaft relief in the left wall and extending away from the left wall on the outboard side of the left wall, and a right drive shaft rotatably attached to the right driven pulley through the drive shaft relief in the right wall and extending away from the right wall on the outboard side of the right wall, as examples. Further, such embodiments may have a left drive belt on the inboard side of the left wall and extending around the left drive pulley and extending around the left driven pulley so as to rotatably connect the left drive pulley to the left driven pulley, for example. Such embodiments may similarly have a right drive belt on the inboard side of the right wall and extending around the right drive pulley and extending around the right driven pulley so as to rotatably connect the right drive pulley to the right driven pulley, for instance.

p-0022In some embodiments, the housing further includes, for example, a central wall between the left wall and the right wall. In such embodiments, the central wall may be between the left drive pulley and the right drive pulley, between the left driven pulley and the right driven pulley, between the left drive belt and the right drive belt, or a combination thereof, for example. Further, in some embodiments, the left drive pulley is supported from both the left wall and the central wall and the right drive pulley is supported from both the right wall and the central wall. Moreover, in some embodiments, the left driven pulley is supported from both the left wall and the central wall and the right driven pulley is supported from both the right wall and the central wall. Even further, in some embodiments, the central wall is a flat plate. Further still, in a number of embodiments, the left wall, the right wall, and the central wall are all parallel to each other, for instance, within five degrees.

p-0023Some embodiments further include a left side adjustable tensioner on the inboard side of the left wall, for example, that adjustably presses a tensioner pulley against the left drive belt between the left drive pulley and the left driven pulley. Such embodiments may also include a right side adjustable tensioner on the inboard side of the right wall that adjustably presses a tensioner pulley against the right drive belt between the right drive pulley and the right driven pulley, for instance. Furthermore, some embodiments include multiple joining walls, for example, extending from the left side wall to the right side wall and holding the left side wall in rigid relation to the right side wall. Even further still, in some embodiments, the left drive pulley and the right drive pulley have a common centerline, the left driven pulley and the right driven pulley have a common centerline, or both.

p-0024Other specific embodiments include various highway vehicles.

p-0025Such vehicles may include, for example, a single, centrally-located transmission housing containing a left drive pulley, a right drive pulley, a left driven pulley, and a right driven pulley. In a number of embodiments, such a transmission further includes a left drive belt extending around the left drive pulley and extending around the left driven pulley so as to rotatably connect the left drive pulley to the left driven pulley, and a right drive belt extending around the right drive pulley and extending around the right driven pulley so as to rotatably connect the right drive pulley to the right driven pulley. Further, such a vehicle may also include a left electric motor rotatably attached to the left drive pulley, a right electric motor rotatably attached to the right drive pulley, and a left drive shaft rotatably attached to the left driven pulley and extending outside of the transmission housing. In a number of embodiments, the left drive shaft includes, for instance, at least one universal joint outside of the transmission housing. Such a vehicle may also include a right drive shaft rotatably attached to the right driven pulley and extending outside of the transmission housing. In a number of embodiments, the right drive shaft also includes, for instance, at least one universal joint outside of the transmission housing. Moreover, such a vehicle may include a left wheel rotatably attached to the left drive shaft, and a right wheel rotatably attached to the right drive shaft.

p-0026In some such embodiments, the transmission housing has an outside surface, the left electric motor is mounted on the outside surface of the transmission housing, and the right electric motor is mounted on the outside surface of the transmission housing. Further, in a number of embodiments, the left drive shaft includes a left decoupler and the right drive shaft includes a right decoupler. Moreover, in particular embodiments, the left wheel and the right wheel are a first wheel and a second wheel at a first end of the vehicle. In a number of embodiments, the vehicle further includes, for instance, a third wheel and a fourth wheel at a second end of the vehicle and an internal combustion engine driving the third wheel and the fourth wheel. Even further, some embodiments include, for example, a battery powering the left electric motor and the right electric motor.

p-0027In certain embodiments, the transmission housing further includes, for instance, a central wall. In a number of embodiments, the central wall is between the left drive pulley and the right drive pulley, the central wall is between the left driven pulley and the right driven pulley, the central wall is between the left drive belt and the right drive belt, or a combination thereof. Further, in various embodiments, the left drive pulley is supported from the central wall, the right drive pulley is supported from the central wall, the left driven pulley is supported from the central wall, the right driven pulley is supported from the central wall, or a combination thereof, as examples. Further, in particular embodiments, such vehicles may include, for example, a left side adjustable tensioner that adjustably presses a tensioner pulley against the left drive belt between the left drive pulley and the left driven pulley, and a right side adjustable tensioner that adjustably presses a tensioner pulley against the right drive belt between the right drive pulley and the right driven pulley. Even further, in certain embodiments, the left drive pulley and the right drive pulley have a common centerline, the left driven pulley and the right driven pulley have a common centerline, or both.

p-0028Still further, in some embodiments, the transmission housing further includes, for instance, a central drive pulley support located between the left drive pulley and the right drive pulley. Moreover, in a number of embodiments, the central drive pulley support includes, for instance, a central drive pulley pin that extends to the left drive pulley and to the right drive pulley to support the left drive pulley and the right drive pulley. Similarly, in some embodiments, the transmission housing further includes a central driven pulley support located between the left driven pulley and the right driven pulley. Further, in a number of embodiments, the central driven pulley support includes, for instance, a central driven pulley pin that extends to the left driven pulley and to the right driven pulley to support the left driven pulley and the right driven pulley.

p-0029In still other specific embodiments, the invention includes a number of methods, for example, of manufacturing a vehicle. Such methods may include, for instance, in the order indicated here, or in another order, at least certain acts. Such acts may include, for example, manufacturing, obtaining, or providing an electric powertrain. Such a powertrain may include, for example, a housing including, for instance, a left wall and a right wall, the left wall having an inboard side facing the right wall and an outboard side facing away from the right wall, and the right wall having an inboard side facing the left wall and an outboard side facing away from the left wall. In a number of embodiments, the left wall and the right wall each have a motor shaft hole and a drive shaft hole, for example. Further, various embodiments include a left electric motor, for example, mounted on the outboard side of the left wall at the motor shaft hole in the left wall and having a rotatable motor shaft. Similarly a number of embodiments include a right electric motor, for instance, mounted on the outboard side of the right wall at the motor shaft hole in the right wall and having a rotatable motor shaft.

p-0030Moreover, such a powertrain may include a left drive pulley located on the inboard side of the left wall and rotatably attached to the rotatable motor shaft of the left motor through the motor shaft hole in the left wall, and a right drive pulley located on the inboard side of the right wall and rotatably attached to the rotatable motor shaft of the right motor through the motor shaft hole in the right wall. Still further, various embodiments may include a left driven pulley located on the inboard side of the left wall at the drive shaft hole in the left wall, and a right driven pulley located on the inboard side of the right wall at the drive shaft hole in the right wall. In a number of embodiments, the left driven pulley and the right driven pulley may have a common centerline, for example. Even further still, such a powertrain may include a left drive shaft, for example, rotatably attached to the left driven pulley through the drive shaft hole in the left wall and extending away from the left wall on the outboard side of the left wall, and a right drive shaft, for instance, rotatably attached to the right driven pulley through the drive shaft hole in the right wall and extending away from the right wall on the outboard side of the right wall.

p-0031Furthermore, such a powertrain manufactured, obtained, or provided in such a method may further include a left drive belt on the inboard side of the left wall and extending around the left drive pulley and extending around the left driven pulley so as to rotatably connect the left drive pulley to the left driven pulley. Similarly, such a powertrain may include a right drive belt on the inboard side of the right wall and extending around the right drive pulley and extending around the right driven pulley so as to rotatably connect the right drive pulley to the right driven pulley. Additionally, in such embodiments, the powertrain may include a central wall between the left wall and the right wall. In a number of embodiments, for example, the central wall is between the left drive pulley and the right drive pulley, the central wall is between the left driven pulley and the right driven pulley, and the central wall is between the left drive belt and the right drive belt. Moreover, in a number of such embodiments, the left driven pulley is supported from both the left wall and the central wall, and the right driven pulley is supported from both the right wall and the central wall.

p-0032Still further, in a number of such methods, the electric powertrain may include a left side adjustable tensioner, for example, on the inboard side of the left wall, that adjustably presses a tensioner pulley against the left drive belt between the left drive pulley and the left driven pulley, and a right side adjustable tensioner, for instance, on the inboard side of the right wall, that adjustably presses a tensioner pulley against the right drive belt between the right drive pulley and the right driven pulley. Such a powertrain may further include multiple joining walls extending from the left side wall to the right side wall, for example, and holding the left side wall in rigid relation to the right side wall.

p-0033Even further, such a method may include, for example, acts of manufacturing, obtaining, or providing two universal joints in the left drive shaft, and two universal joints in the right drive shaft, manufacturing, obtaining, or providing a left first wheel rotatably attached to the left drive shaft at a first end of the vehicle, a right second wheel rotatably attached to the right drive shaft at the first end of the vehicle, a left third wheel at a second end of the vehicle, and a right fourth wheel at the second end of the vehicle. Even further still, such a method may include manufacturing, obtaining, or providing a battery powering the left electric motor and the right electric motor.

p-0034In addition, various other embodiments of the invention are also described herein, and other benefits of certain embodiments may be apparent to a person of ordinary skill in the art.

DETAILED DESCRIPTION OF EXAMPLES OF EMBODIMENTS

p-0035The subject matter described herein includes, as examples, various vehicles including highway vehicles, powertrains such as electric vehicle powertrains, and methods, for example, of manufacturing such vehicles and powertrains. As used herein, an electric vehicle is a vehicle that uses electricity to drive the vehicle, for example, using one or more electric motors to turn one or more wheels of the vehicle. The electric motors may be powered from a generator or battery on the vehicle, or from an external source, as examples. In different embodiments, an electric vehicle may be powered using a fuel cell, a solar collector, a generator turned by an engine, such as an internal combustion engine, or a combination thereof, as examples. Further, as used herein, hybrid electric vehicles are a type of electric vehicle. Furthermore, as used herein, a highway vehicle is a type of vehicle that is suitable for licensing and operation on public highways and city streets.

p-0036The drawings include reference numbers used in this section that refer to parts or all of the subject matter illustrated. There may be exceptions, but generally, each reference number is found in the figure that has the same number as the first digit of the reference number (the first two digits in the case of <figref idrefs="DRAWINGS">FIG. 10</figref>). For many of the reference numbers, however, that same reference number, and the component or aspect to which that number refers, may be found in other figures as well. Referring to the drawings, <figref idrefs="DRAWINGS">FIG. 1</figref> illustrates an example of a highway vehicle, vehicle <b>10</b>, that includes wheels <b>11</b>, <b>12</b>, <b>13</b>, and <b>14</b>, electric vehicle powertrain <b>15</b>, battery <b>16</b>, internal combustion engine <b>17</b>, and transmission <b>18</b>. Other components of vehicle <b>10</b> have been omitted for clarity including the frame, body, suspension (e.g., double wishbone, coil springs, and shocks), wiring, controls, steering system, exhaust system, fuel system, pollution control systems, control systems, interior, doors, glass, and safety equipment. Examples of such components and systems, and other omitted components and systems, however, are known in the art.

p-0037In the embodiment illustrated, engine <b>17</b> is a V8 spark-ignition fuel injected engine with eight individual velocity stacks. Other embodiments, however, may have one or more carburetors or direct injection, as other examples. Further, various embodiments may have 3, 4 (e.g., in line or horizontally opposed), 5, 6 (e.g., in line, vee, or horizontally opposed), 10, or 12 cylinders, may have two or four overhead cams, may have variable valve timing for the intake valves, exhaust valves, or both, may be naturally aspirated or turbocharged (e.g., and intercooled) or a combination thereof, as examples. In various embodiments, engine <b>17</b> may be a spark-ignition engine or a compression ignition (i.e., Diesel) engine, and may have port-type fuel injection or direct injection, for instance In different embodiments, vehicle <b>10</b> may be a mass produced vehicle, a limited production vehicle (e.g., a supercar), a highway vehicle (e.g., license to use on public highways and streets) a race car, an off-road vehicle, a truck, or a military vehicle, as examples.

p-0038Transmission <b>18</b> may deliver power from engine <b>17</b> to wheels <b>13</b> and <b>14</b> at end <b>192</b> of vehicle <b>10</b>. Transmission <b>18</b> may be an automatic or manual transmission, as examples. In some embodiments, transmission <b>18</b> may be a dual clutch transmission (DCT) or a continuously variable transmission (CVT) as examples. Transmission <b>18</b> may include a differential, which may be open or limited slip (e.g., clutch, geared, viscous, gerotor, electronic, or locking). Drive shafts may connect transmission <b>18</b> to wheels <b>13</b> and <b>14</b>. In different embodiments, these driveshafts may each have one or two universal joints (e.g., constant-velocity joints), for example. In some embodiments, vehicle <b>10</b> may use engine <b>17</b> for locomotion whenever vehicle <b>10</b> is in motion, but drivetrain <b>15</b> may be used, with power from battery <b>16</b>, to launch the vehicle, to pass, for hard cornering, in situations where traction is limited, or a combination thereof, as examples. In some embodiments, drivetrain <b>15</b> may be used for regenerative braking, and motors <b>151</b> and <b>152</b> may generate electricity that may be stored in battery <b>16</b>. Further, in some embodiments, vehicle <b>10</b> may be plugged in to a charger or wall outlet when vehicle <b>10</b> is parked to charge battery <b>16</b>. Further, in some embodiments, a generator may be connected to engine <b>17</b> or motors <b>151</b> and <b>152</b> may be used to generate electricity to charge battery <b>16</b> while vehicle <b>10</b> is in motion.

p-0039In the embodiment illustrated, vehicle <b>10</b> (e.g., at end <b>191</b>) and powertrain <b>15</b> also includes a single, centrally-located transmission <b>155</b>, left electric motor <b>151</b>, and right electric motor <b>152</b>. <figref idrefs="DRAWINGS">FIGS. 2-9</figref> illustrate various parts of powertrain <b>15</b> with certain components omitted from some views for clarity. As used herein, a statement that there is a “single” transmission (e.g., <b>155</b>) containing certain components does not exclude the possibility that there is another transmission (e.g., <b>18</b>) on the vehicle (e.g., driving other wheels of the vehicle). Further, as used herein, “centrally located”, when referring to a transmission (e.g., <b>155</b>) means that the transmission is located between the drive wheels (e.g., <b>11</b> and <b>12</b>). Even further, in certain embodiments, a point on a common centerline (e.g., neglecting any toe in or camber) of the two wheels, that is equal distant from the two wheels, falls within the space occupied by the (e.g., housing of the) transmission.

p-0040As shown in <figref idrefs="DRAWINGS">FIG. 2</figref>, transmission <b>155</b> includes centrally-located housing <b>25</b> (e.g., transmission housing). In the embodiment illustrated, centrally-located (e.g., transmission) housing <b>25</b> contains left drive pulley <b>41</b> right drive pulley <b>42</b>, left driven pulley <b>43</b>, and right driven pulley <b>44</b>, shown, for example, in <figref idrefs="DRAWINGS">FIGS. 4 and 7</figref>. In the embodiment shown, transmission <b>155</b> and housing <b>25</b> further includes left drive belt <b>31</b> (e.g., shown in <figref idrefs="DRAWINGS">FIG. 3</figref>) extending around left drive pulley <b>41</b> and extending around left driven pulley <b>43</b> so as to rotatably connect left drive pulley <b>41</b> to left driven pulley <b>43</b>. As used herein, two components that rotate (i.e., about an axis relative to other structure) are considered to be “rotatably connected” if when one component rotates, the other rotates proportionally. Further, in the embodiment shown, transmission <b>155</b> and housing <b>25</b> further include right drive belt <b>32</b> extending around right drive pulley <b>42</b> and extending around right driven pulley <b>44</b> so as to rotatably connect right drive pulley <b>42</b> to right driven pulley <b>44</b>. Belts <b>31</b> and <b>32</b> may be flat belts, for instance. In other embodiments, on the other hand, belts <b>31</b> and <b>32</b> may be vee belts. Further, in certain embodiments, belts <b>31</b> and <b>32</b> may be multi-vee belts. Even further, in some embodiments, belts <b>31</b> and <b>32</b> may be cogged belts, for example, of the configuration that has been used as timing belts. Belts <b>31</b> and <b>32</b> may be of a type used for motorcycle drives, for example. In some embodiments, belts <b>31</b> and <b>32</b> may be fiber reinforced, for instance, carbon reinforced.

p-0041In this embodiment shown, the left and right sides of drivetrain <b>15</b> are symmetrical (e.g., have corresponding parts on opposite sides, for example, of center wall <b>29</b>, that are of the same size, which are in some cases identical and in some cases opposite hand) and yet drive the left and right wheels (e.g., <b>11</b> and <b>12</b>) independently (e.g., at different speeds, different torques, or both). In the embodiment shown, left drive pulley <b>41</b> and right drive pulley <b>42</b> have a common centerline, and left driven pulley <b>43</b> and right driven pulley <b>44</b> have a common centerline. In other embodiments, however, left drive pulley <b>41</b> and right drive pulley <b>42</b> have a common centerline, but left driven pulley <b>43</b> and right driven pulley <b>44</b> do not have a common centerline. Further, in still other embodiments, however, left drive pulley <b>41</b> and right drive pulley <b>42</b> do not have a common centerline, but left driven pulley <b>43</b> and right driven pulley <b>44</b> do have a common centerline. Even further in yet other embodiments, left drive pulley <b>41</b> and right drive pulley <b>42</b> do not have a common centerline, and left driven pulley <b>43</b> and right driven pulley <b>44</b> do not have a common centerline. As used herein, two centerlines are considered to be “common” if they are within ¼ inch offset at a closest point and are within 5 degrees angular variation. Other embodiments are within ⅛, %, 1, or 2 inch(es) offset and within 1, 2, 4, 7, 10, or 15 degrees angular variation, as other examples.

p-0042Further, in the embodiment illustrated of vehicle <b>10</b> and powertrain <b>15</b>, left electric motor <b>151</b> is rotatably attached to left drive pulley <b>41</b>, and right electric motor <b>152</b> is rotatably attached to right drive pulley <b>42</b>. As used herein, two components are “rotatably attached” if both components rotate and the two components are connected together (e.g., directly or indirectly) such that when one rotates, the other component rotates at the same speed. Even further, in the embodiment shown, left drive shaft <b>21</b> is rotatably attached to left driven pulley <b>43</b>. As shown, left drive shaft <b>21</b> extends outside of (e.g., transmission) housing <b>25</b>. Similarly, in the embodiment shown, right drive shaft <b>22</b> is rotatably attached to right driven pulley <b>44</b>, and right drive shaft <b>22</b> extends outside of housing <b>25</b>. In a number of embodiments, each (e.g., left and right) drive shaft includes, for instance, at least one universal joint outside of the housing (e.g., transmission housing). As shown best in <figref idrefs="DRAWINGS">FIG. 2</figref>, left drive shaft <b>21</b> includes inboard universal joint <b>23</b> and outboard universal joint <b>27</b>, and right drive shaft <b>22</b> includes inboard universal joint <b>24</b> and outboard universal joint <b>28</b>. Universal joints <b>23</b>, <b>24</b>, <b>27</b>, and <b>28</b> may be constant-velocity (CV) joints, for example. Moreover, as shown in <figref idrefs="DRAWINGS">FIG. 1</figref>, vehicle <b>10</b> includes left wheel <b>11</b> rotatably attached to left drive shaft <b>21</b>, and right wheel <b>12</b> rotatably attached to right drive shaft <b>22</b>.

p-0043In this embodiment, powertrain <b>15</b>, including housing <b>25</b> and the contents thereof, is sprung weight (other than part of driveshafts <b>21</b> and <b>22</b> outboard of universal joints <b>23</b> and <b>24</b>). As a result, unsprung weight or mass of vehicle <b>10</b> is minimized, for example, in comparison with alternatives wherein motors, pulleys, part of belts, etc., move (e.g., up and down) with the wheels (e.g., <b>11</b> and <b>12</b>). This may provide better wheel contact with the road, for instance, on uneven surfaces, and may provide better vehicle handling at speed. This may be a significant improvement, for example, over motorcycle powertrains or drivetrains that use belts. Further, in the embodiment depicted, drive pulleys <b>41</b> and <b>42</b> are the same size (e.g., diameter) and driven pulleys <b>43</b> and <b>44</b> are the same size, but drive pulleys <b>41</b> and <b>42</b> are smaller than driven pulleys <b>43</b> and <b>44</b>. This provides a speed reduction and increase in torque (e.g., from motor to wheel). The speed ratio may be, for example, 3:1, 3.5:1, or 4:1, as examples. Other embodiments may have a different speed or diameter ratio.

p-0044In the embodiment shown, housing <b>25</b> (e.g., transmission housing) has outside surface <b>26</b> and left electric motor <b>151</b> is mounted on outside surface <b>26</b> of housing <b>25</b>. Further, in this embodiment, right electric motor <b>152</b> is mounted on outside surface <b>26</b> of (e.g., transmission) housing <b>25</b>. Further, as shown in <figref idrefs="DRAWINGS">FIGS. 2 and 4</figref>, left drive shaft <b>21</b> includes left decoupler <b>47</b> and right drive shaft <b>22</b> includes right decoupler <b>48</b>. Decouplers <b>47</b> and <b>48</b> are operated by solenoids or servos <b>475</b> and <b>485</b> in the embodiment illustrated. In this embodiment, decouplers <b>47</b> and <b>48</b> disconnect (i.e., rotatably decouple) wheels <b>11</b> and <b>12</b> from driven pulleys <b>43</b> and <b>44</b> when decouplers <b>47</b> and <b>48</b> are decoupled. This may be done, for example, to reduce friction and losses when vehicle <b>10</b> is moving but electric vehicle powertrain <b>15</b> is not in use (e.g., when engine <b>17</b> is driving vehicle <b>10</b> through transmission <b>18</b> and further power from powertrain <b>15</b> is not needed). Further, decouplers <b>47</b> and <b>48</b> rotatably connect, and rotatably attach wheels <b>11</b> and <b>12</b> to driven pulleys <b>43</b> and <b>44</b> when decouplers <b>47</b> and <b>48</b> are coupled. Even further, as used herein, wheels <b>11</b> and <b>12</b> are considered to be “rotatably attached” to driven pulleys <b>43</b> and <b>44</b> in embodiments, such as the embodiment illustrated, that are provided with decouplers <b>47</b> and <b>48</b> that can be decoupled at certain times. Further, in some embodiments, when vehicle <b>10</b> is in motion, when decouplers <b>47</b> and <b>48</b> are about to be coupled, motors <b>151</b> and <b>152</b> may first be driven (e.g., by the controller or variable-speed drive, using power from battery <b>16</b>, for example) to synchronize the speed so that the speed difference across decouplers <b>47</b> and <b>48</b> is near zero. Once this is done, decouplers <b>47</b> and <b>48</b> may be coupled.

p-0045In a number of embodiments, motors <b>151</b> and <b>152</b> and powertrain <b>15</b> provide independent control (e.g., delivery of torque) to wheels <b>11</b> and <b>12</b> of vehicle <b>10</b> for torque vectoring or torque biasing, for example. This feature can be used, for example, to control wheel spin (e.g., for traction control), to help steer the vehicle, to provide stability control, to control the amount of oversteer or understeer that is induced when cornering, or a combination thereof, as examples. Motors <b>151</b> and <b>152</b> may be alternating current (AC) (e.g., brushless) or direct current (DC) motors, in different embodiments. Each motor <b>151</b> and <b>152</b> may have a variable-speed power supply or drive, for example, a variable-frequency AC drive or a variable-voltage DC drive. Motors <b>151</b> and <b>152</b> may be controlled, or the variable-speed drives may be controlled, for example, by a digital controller, for instance.

p-0046Referring to <figref idrefs="DRAWINGS">FIG. 1</figref>, in the embodiment illustrated, left wheel <b>11</b> and right wheel <b>12</b> are a first wheel and a second wheel at first end <b>191</b> of vehicle <b>10</b>. In this embodiment, vehicle <b>10</b> further includes third wheel <b>13</b> and fourth wheel <b>14</b> at second end <b>192</b> of vehicle <b>19</b>. Moreover, in this embodiment, internal combustion engine <b>17</b> drives third wheel <b>13</b> and fourth wheel <b>14</b> through transmission <b>18</b>. In a number of embodiments, first end <b>191</b> is the front of vehicle <b>10</b> and second end <b>192</b> is the rear of vehicle <b>10</b>. In other embodiments, however, the first end of the vehicle may be the rear and the second end may be the front. In other words, in different embodiments, the engine may drive either the rear wheels or the front wheels, and one or more electric motors (e.g., <b>151</b> and <b>152</b>) may drive the wheels at the opposite end of the vehicle. Still other embodiments may have electric powertrains (e.g., <b>15</b>) at both ends (e.g., <b>191</b> and <b>192</b>, front and back) of the vehicle, as another example.

p-0047Even further, some embodiments include, for example, a battery (e.g., <b>16</b> shown in <figref idrefs="DRAWINGS">FIG. 1</figref>) powering the left electric motor (e.g., <b>151</b>) and the right electric motor (e.g., <b>152</b>). Such a vehicle may be a hybrid electric vehicle, for instance (e.g., as shown) or may be a fully electric (e.g., no engine) vehicle. In some embodiments, the electric motor or motors (e.g., <b>151</b> and <b>152</b>) may act as a generator during braking and may charge battery <b>16</b> to recover a portion of the braking energy that otherwise would be lost. Other embodiments, however, may lack a battery used to power the drive motors. Rather, in some embodiments, a generator (e.g., driven by the engine, for instance, <b>17</b>) may power the electric motor or motors (e.g., <b>151</b> and <b>152</b>). In some embodiments, providing power and torque to wheels not mechanically driven by the engine (e.g., by engine <b>17</b> through transmission <b>18</b>) may help to move the vehicle in situations where the traction available to the wheels (e.g., <b>13</b> and <b>14</b>) driven by the engine (e.g., by engine <b>17</b> through transmission <b>18</b>) is not sufficient by itself.

p-0048As shown in <figref idrefs="DRAWINGS">FIGS. 2</figref>, <b>3</b>, <b>5</b>, and <b>7</b>, in the embodiment illustrated, housing <b>25</b> further includes central wall <b>29</b>. As shown, in this particular embodiment, central wall <b>29</b> is between left drive pulley <b>41</b> and right drive pulley <b>42</b>, central wall <b>29</b> is between left driven pulley <b>43</b> and right driven pulley <b>44</b>, and central wall <b>29</b> is between left drive belt <b>31</b> and right drive belt <b>32</b>. Further, in this embodiment, left drive pulley <b>41</b> is supported from central wall <b>29</b>, right drive pulley <b>42</b> is supported from central wall <b>29</b>, left driven pulley <b>43</b> is supported from central wall <b>29</b>, and right driven pulley <b>44</b> is supported from central wall <b>29</b>. How these pulleys are supported from central wall <b>29</b>, in the embodiment illustrated, is shown in more detail in <figref idrefs="DRAWINGS">FIG. 7</figref>.

p-0049Still further, in housing <b>25</b>, central wall <b>29</b> is an example of, or part of, a central drive pulley support located, for instance, between left drive pulley <b>41</b> and right drive pulley <b>42</b>. The shape of central wall <b>29</b> is shown, for example, in <figref idrefs="DRAWINGS">FIG. 5</figref>. Moreover, as shown in <figref idrefs="DRAWINGS">FIG. 7</figref>, central drive pulley support <b>70</b> includes central drive pulley pin <b>73</b> that extends to left drive pulley <b>41</b> and to right drive pulley <b>42</b> to support left drive pulley <b>41</b> and right drive pulley <b>42</b>. In the embodiment illustrated, central drive pulley pin <b>73</b> is attached to central wall <b>29</b> with flange <b>74</b> and multiple fasteners that extend through holes in flange <b>74</b> and central wall <b>29</b>. Further, in the embodiment illustrated, central drive pulley pin <b>73</b> extends through a hole in central wall <b>29</b> and extends into left drive pulley <b>41</b> and right drive pulley <b>42</b>. In this particular embodiment, left drive bearing <b>731</b> supports left drive pulley <b>41</b> from central drive pulley pin <b>73</b> and right drive bearing <b>732</b> supports right drive pulley <b>42</b> from central drive pulley pin <b>73</b>. In the embodiment shown, central drive pulley pin <b>73</b> is solid. In various embodiments, bearings may be needle, roller, or ball bearings, for example. In the embodiment shown, bearings <b>711</b>-<b>714</b> are ball bearings and bearings <b>731</b> and <b>732</b> are needle bearings. Further, housing <b>25</b> is not sealed, so individually sealed bearings may be used in the embodiment illustrated. Permanently lubricated bearings may be used in some embodiments.

p-0050In other embodiments, however, a central pulley pin may be hollow. In some embodiments, for example, the drive pulleys may each have a shaft that turns with the pulley that extends, for example, to the central wall, central support, or into a hollow central pulley pin. In certain embodiments of this type described, bearings may be provided between the shaft that turns with the pulley and the hollow central pulley pin, for instance. As used herein, a pin extends “to” a pulley if the pin extends inside the pulley, if the pin extends to surround and support part of a shaft that is concentric with and supports the pulley, or if the pin touches the pulley during any part of the range of motion of the pulley, whether the pin touches the pulley directly or through a bearing. Still other embodiments may omit a central pulley pin (e.g., for the drive pulley, driven pulley, or both) but may include a central pulley support (e.g., for the drive pulley, driven pulley, or both) that is formed or machined into the central wall. In particular embodiments, a bearing is pressed into a hole in the central wall, for example, that supports the pulley or pulleys.

p-0051In the embodiment illustrated, left drive pulley <b>41</b> and right drive pulley <b>42</b> are also supported by rotatable motor shafts <b>71</b> and <b>72</b> (i.e., of motors <b>151</b> and <b>152</b> shown, for example, in <figref idrefs="DRAWINGS">FIGS. 1-2</figref>). In the embodiment shown, motor shafts <b>71</b> and <b>72</b> are rotatably mounted in bearings <b>711</b>, <b>713</b>, <b>712</b>, and <b>714</b>. In other embodiments, however, drive pulleys, such as <b>41</b> and <b>42</b>, may be supported only by the motor shafts, and the central drive pulley support, central pulley pin, central wall, or a combination thereof, may be omitted. In still other embodiments, drive pulleys, such as <b>41</b> and <b>42</b>, may be supported only by the central drive pulley support, central pulley pin, central wall, or a combination thereof, and not by the motor shafts, as another example.

p-0052Similarly, in housing <b>25</b>, central wall <b>29</b> is an example of, or part of, a central driven pulley support located between left driven pulley <b>43</b> and right driven pulley <b>44</b>. As shown in <figref idrefs="DRAWINGS">FIG. 7</figref>, central driven pulley support <b>75</b> includes, for instance, central driven pulley pin <b>78</b> (also shown in <figref idrefs="DRAWINGS">FIG. 8</figref>) that extends to left driven pulley <b>43</b> and to right driven pulley <b>44</b> to support left driven pulley <b>43</b> and right driven pulley <b>44</b>. As shown in <figref idrefs="DRAWINGS">FIG. 7</figref>, central driven pulley pin <b>78</b> is attached to central wall <b>29</b> with flange <b>79</b> and multiple fasteners that extend through holes in flange <b>79</b> and central wall <b>29</b>. Further, in the embodiment illustrated, central driven pulley pin <b>78</b> extends through a hole in central wall <b>29</b> and extends into left driven pulley <b>43</b> and right driven pulley <b>44</b>. In this particular embodiment, left driven bearing <b>781</b> supports left driven pulley <b>43</b> from central driven pulley pin <b>78</b> and right driven bearing <b>782</b> supports right driven pulley <b>44</b> from central driven pulley pin <b>78</b>. In the embodiment shown, central driven pulley pin <b>78</b> is solid.

p-0053In other embodiments, however, the central driven pulley support, central driven pulley pin, or both, may be as described herein for various embodiments of the central driven pulley support, central drive pulley pin, or both. For example, in some embodiments, the central driven pulley pin may be hollow. Further, in other embodiments, the central driven pulley pin or central driven pulley support may be omitted or may provide complete support for the driven pulleys. Moreover, in the embodiment shown, drive shafts <b>21</b> and <b>22</b> inboard of universal joints <b>23</b> and <b>24</b> are rotatably mounted in bearings <b>716</b>, <b>718</b>, <b>717</b>, and <b>719</b>. In other embodiments, however, driven pulleys, such as <b>43</b> and <b>44</b>, may be supported only by the drive shafts, and the central driven pulley support, central driven pulley pin, central wall, or a combination thereof, may be omitted. In still other embodiments, driven pulleys, such as <b>43</b> and <b>44</b>, and drive shafts, such as <b>21</b> and <b>22</b> inboard of universal joints <b>23</b> and <b>24</b>, for example, may be supported by a central driven pulley support, by a central driven pulley pin, by a central wall (e.g., <b>29</b>), or by a combination thereof, and by one other bearing per shaft (e.g., <b>716</b> or <b>718</b> and <b>717</b> or <b>719</b>), as another example.

p-0054Further, in the embodiment shown, vehicle <b>10</b>, powertrain <b>15</b>, and centrally-located transmission <b>155</b> include, for example, a left side adjustable tensioner <b>36</b> that adjustably presses tensioner pulley <b>38</b> against left drive belt <b>31</b> between left drive pulley <b>41</b> and left driven pulley <b>43</b>, and right side adjustable tensioner <b>37</b> that adjustably presses tensioner pulley <b>39</b> against right drive belt <b>32</b> between right drive pulley <b>42</b> and right driven pulley <b>44</b>. See <figref idrefs="DRAWINGS">FIG. 3</figref>, for example. As used herein, “adjustable”, when referring to a tensioner, means that a person can adjust the tension (e.g., using hand tools) in a reversible manner without replacing or plastically deforming any components of the powertrain weighing over one pound. In the embodiment shown, tensioners <b>36</b> and <b>37</b> include threaded rods <b>33</b> and <b>34</b> (respectively) that can be rotated (e.g., manually) to independently adjust belt tension.

p-0055As shown in <figref idrefs="DRAWINGS">FIGS. 2</figref>, <b>3</b>, <b>5</b>, and <b>6</b>, electric vehicle powertrain <b>15</b> includes housing <b>25</b> that includes left wall <b>251</b> and right wall <b>252</b>. Left wall <b>251</b>, in this embodiment, has inboard side <b>331</b> (shown in <figref idrefs="DRAWINGS">FIG. 3</figref>) facing right wall <b>252</b> and outboard side <b>261</b> (shown in <figref idrefs="DRAWINGS">FIG. 2</figref>) facing away from right wall <b>252</b>. Further, right wall <b>252</b>, in the embodiment shown, has inboard side <b>232</b> (shown in <figref idrefs="DRAWINGS">FIG. 2</figref>) facing left wall <b>251</b> and outboard side <b>262</b> facing away from left wall <b>251</b>. In the embodiment illustrated, outboard side <b>261</b> of left wall <b>251</b> and outboard side <b>262</b> or right wall <b>252</b> each form part of outside surface <b>26</b> of housing <b>25</b>. Additionally, <figref idrefs="DRAWINGS">FIG. 9</figref> illustrates right wall <b>252</b> by itself. In the embodiment illustrated, left wall <b>251</b> is a mirror image of right wall <b>252</b>. In the embodiment shown, left wall <b>251</b> and right wall <b>252</b> each have a motor shaft relief and a drive shaft relief, for instance. As shown in <figref idrefs="DRAWINGS">FIG. 9</figref>, in the embodiment illustrated, right wall <b>252</b> includes motor shaft relief <b>91</b> and drive shaft relief <b>92</b>. Left Wall <b>251</b> may be similar (e.g., opposite hand). In the embodiment shown, motor shaft relief <b>91</b> and drive shaft relief <b>92</b> are round holes through right wall <b>252</b>, for example. In other embodiments, the motor shaft relief, the drive shaft relief, or both, may be another shape opening suitable to pass a shaft, such as a hole of another shape (e.g., polygonal, oval, a slot, square, rectangular, triangular, pentagonal, hexagonal, octagonal, or star shaped) or may extend to a side of the wall (e.g., have a C shape or be shaped like a bay in the wall).

p-0056As shown in <figref idrefs="DRAWINGS">FIG. 2</figref>, right electric motor <b>152</b> is mounted on outboard side <b>262</b> (i.e., opposite inboard side <b>232</b> shown in <figref idrefs="DRAWINGS">FIGS. 2</figref>, <b>5</b>, <b>6</b>, and <b>9</b>) of right wall <b>252</b> at motor shaft relief <b>91</b> in right wall <b>252</b>. Motor <b>152</b> may be attached to wall <b>252</b> with fasteners (e.g., bolts or screws), which may extend into or through holes <b>95</b> shown in <figref idrefs="DRAWINGS">FIGS. 5</figref>, <b>6</b>, and <b>9</b>. In the embodiment illustrated, in fact, right electric motor <b>152</b> is mounted concentrically (e.g., within +/−0.0625 inches) with motor shaft relief <b>91</b> in right wall <b>252</b>. In other embodiments, however, the electric motor, motors, shaft, or shafts may not be concentric with the relief or reliefs, as other examples. As shown in <figref idrefs="DRAWINGS">FIGS. 3 and 7</figref>, right electric motor <b>152</b> has rotatable motor shaft <b>72</b> which extends through motor shaft relief <b>91</b> in right wall <b>252</b> and rotatably attaches to drive pulley <b>42</b>. <figref idrefs="DRAWINGS">FIG. 7</figref> also shows walls <b>251</b> and <b>252</b> and reliefs <b>91</b> and <b>92</b> therein. In the embodiment illustrated, left electric motor <b>151</b> is mounted on outboard side <b>261</b> of left wall <b>251</b> at motor shaft relief <b>91</b> (shown in <figref idrefs="DRAWINGS">FIG. 7</figref>) in left wall <b>251</b>. Left electric motor <b>151</b> may be mounted to left wall <b>251</b> similarly to how right electric motor is mounted to right wall <b>252</b>, for example.

p-0057In the embodiment shown, left drive pulley <b>41</b> located on inboard side <b>331</b> of left wall <b>251</b> is rotatably attached to rotatable motor shaft <b>71</b> of left motor <b>151</b> through motor shaft relief <b>91</b> in left wall <b>251</b>. Specifically, in this embodiment, shaft <b>71</b> extends through relief <b>91</b> through left wall <b>251</b>. Similarly, in this particular embodiment, right drive pulley <b>42</b> located on inboard side <b>232</b> of right wall <b>252</b> and is rotatably attached to rotatable motor shaft <b>72</b> of right motor <b>152</b> through the motor shaft relief <b>91</b> in right wall <b>252</b>. Moreover, in the embodiment illustrated, left driven pulley <b>43</b> is located on inboard side <b>331</b> of left wall <b>251</b> at (e.g., concentric with) drive shaft relief <b>92</b> in left wall <b>251</b>, and right driven pulley <b>44</b> is located on inboard side <b>232</b> of right wall <b>252</b> at (e.g., concentric with) drive shaft relief <b>92</b> in right wall <b>252</b>. Further, in this embodiment, as used herein, left drive shaft <b>21</b> is rotatably attached to left driven pulley <b>43</b> through drive shaft relief <b>92</b> in left wall <b>251</b>. Further still, left drive shaft <b>21</b> extends away from left wall <b>251</b> on outboard side <b>261</b> of left wall <b>251</b>. Moreover, in this embodiment, as used herein, right drive shaft <b>22</b> is rotatably attached to right driven pulley <b>44</b> through drive shaft relief <b>92</b> in right wall <b>252</b> and extends away from right wall <b>252</b> on outboard side <b>262</b> of right wall <b>252</b>. Even further, this particular embodiment includes left drive belt <b>31</b> on inboard side <b>331</b> of left wall <b>251</b>. Left drive belt <b>31</b> extends around left drive pulley <b>41</b> and around left driven pulley <b>43</b> so as to rotatably connect left drive pulley <b>41</b> to left driven pulley <b>43</b>. Similarly, right drive belt <b>32</b> on inboard side <b>232</b> of right wall <b>252</b> extends around right drive pulley <b>42</b> and around right driven pulley <b>44</b> so as to rotatably connect right drive pulley <b>42</b> to right driven pulley <b>44</b>. Still further, in the embodiment illustrated, left side adjustable tensioner <b>36</b> is on inboard side <b>331</b> of left wall <b>251</b>, and right side adjustable tensioner <b>37</b> is on inboard side <b>232</b> of right wall <b>252</b>.

p-0058As mentioned, housing <b>25</b> further includes central wall <b>29</b> between left wall <b>251</b> and right wall <b>252</b>. Central wall <b>29</b> is also between left drive pulley <b>41</b> and right drive pulley <b>42</b>, between left driven pulley <b>43</b> and right driven pulley <b>44</b>, and between left drive belt <b>31</b> and right drive belt <b>32</b>, in this embodiment. Further, in this embodiment, left drive pulley <b>41</b> is supported from both left wall <b>251</b> and central wall <b>29</b> and right drive pulley <b>42</b> is supported from both right wall <b>252</b> and central wall <b>29</b>. Moreover, in the embodiment illustrated, as used herein, left driven pulley <b>43</b> is supported from both left wall <b>251</b> and central wall <b>29</b> and right driven pulley <b>44</b> is supported from both right wall <b>252</b> and central wall <b>29</b>. Even further, in the embodiment shown, central wall <b>29</b> is a flat plate. Still further, in this particular embodiment, left wall <b>251</b> and right wall <b>252</b> are both flat plates. Further still, in the embodiment illustrated, left wall <b>251</b>, right wall <b>252</b>, and central wall <b>29</b> are all parallel to each other, for example, within five degrees.

p-0059In the embodiment shown, central wall <b>29</b>, left wall <b>251</b>, and right wall <b>252</b> are each cut or machined from wrought or rolled metal plate (e.g., steel or aluminum), for example. In other embodiments, central wall <b>29</b>, left wall <b>251</b>, right wall <b>252</b>, or a combination thereof, may be cast (e.g., together or separately) stamped, bent, rolled, extruded, or forged, as other examples. Further, in some embodiments, left wall <b>251</b>, right wall <b>252</b>, and central wall <b>29</b> (or a subset thereof) are parallel to each other within 0.25, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, or 20 degrees, as examples.

p-0060Furthermore, the embodiment of housing <b>25</b> shown includes multiple joining walls <b>351</b>, <b>352</b>, <b>353</b>, <b>354</b>, <b>355</b>, and <b>356</b> that (as used herein) extend from left side wall <b>251</b> to right side wall <b>252</b> and hold left side wall <b>251</b> in rigid relation to right side wall <b>252</b>. See <figref idrefs="DRAWINGS">FIGS. 2</figref>, <b>3</b>, and <b>5</b>-<b>7</b>. In this embodiment, joining walls <b>351</b>, <b>353</b>, and <b>355</b> extend from left side wall <b>251</b> to central wall <b>29</b>, and joining walls <b>352</b>, <b>354</b>, and <b>356</b> extend from central wall <b>29</b> to right side wall <b>252</b>. In the embodiment illustrated, bolts <b>358</b> (shown in <figref idrefs="DRAWINGS">FIG. 3</figref>) extend through joining walls <b>351</b>, <b>352</b>, <b>353</b>, <b>354</b>, <b>355</b>, and <b>356</b>, as well as left side wall <b>251</b>, right side wall <b>252</b>, and central wall <b>29</b> to hold housing <b>25</b> together and in rigid relation. In other embodiments, some or all of joining walls <b>351</b>, <b>352</b>, <b>353</b>, <b>354</b>, <b>355</b>, and <b>356</b> may be welded to left side wall <b>251</b>, to right side wall <b>252</b>, to central wall <b>29</b>, or a combination thereof, as other examples.

p-0061In still other embodiments, some or all of joining walls <b>351</b>, <b>352</b>, <b>353</b>, <b>354</b>, <b>355</b>, and <b>356</b>, left side wall <b>251</b>, right side wall <b>252</b>, and central wall <b>29</b> may be cast, for example, as a single piece. In other embodiments, for example, each side wall may be cast with adjacent joining walls, forming a split casing (e.g., in two substantially symmetrical opposite halves, which may bolted together, for example, sandwiching there between a central wall (e.g., formed from a flat plate). Further, in the embodiment illustrated, the interior of housing <b>25</b> (where belts <b>31</b> and <b>32</b> are located is open to the outside between joining walls <b>351</b> and <b>353</b>, <b>352</b> and <b>354</b>, <b>353</b> and <b>355</b>, <b>352</b> and <b>356</b>, <b>351</b> and <b>355</b>, and between <b>252</b> and <b>356</b>. In other embodiments, these openings may be covered (e.g., with sheet metal covers) or the housing, or parts thereof, may be fabricated or cast to omit some or all such openings.

p-0062Still other embodiments include a number of methods, for example, of manufacturing a vehicle. Method <b>100</b> in <figref idrefs="DRAWINGS">FIG. 10</figref> is an example of such a method. Various methods may include, for example, in the order indicated here, or in another order, at least certain acts. Different embodiments include different combinations of the acts illustrated in method <b>100</b>, other acts described herein, or other acts known in the art. Method <b>100</b>, in the embodiment illustrated, includes, for example, act <b>101</b> of manufacturing, obtaining, or providing an electric powertrain (e.g., <b>15</b> described herein). Such a powertrain (e.g., <b>15</b>) may include, for example, various structure described herein such as a housing (e.g., <b>25</b>) including, for instance, a left wall (e.g., <b>251</b>) and a right wall (e.g., <b>252</b>). The left wall (e.g., <b>251</b>) may have an inboard side (e.g., <b>331</b>) facing the right wall (e.g., <b>252</b>) and an outboard side (e.g., <b>261</b>) facing away from the right wall (e.g., <b>252</b>). Further, the right wall (e.g., <b>252</b>) may have an inboard side (e.g., <b>232</b>) facing the left wall (e.g., <b>251</b>) and an outboard side (e.g., <b>262</b>) facing away from the left wall (e.g., <b>251</b>). In a number of embodiments, the left wall (e.g., <b>251</b>) and the right wall (e.g., <b>252</b>) each have a motor shaft hole (e.g., motor shaft relief <b>91</b> shown in <figref idrefs="DRAWINGS">FIG. 9</figref>) and a drive shaft hole (e.g., drive shaft relief <b>92</b>), for example.

p-0063Further, such a powertrain (e.g., <b>15</b>) may include a left electric motor (e.g., <b>151</b>), for example, mounted on the outboard side (e.g., <b>261</b>) of the left wall (e.g., <b>251</b>) at the motor shaft hole (e.g., relief <b>91</b>) in the left wall (e.g., <b>251</b>) and having a rotatable motor shaft (e.g., <b>71</b>). Similarly a number of embodiments include a right electric motor (e.g., <b>152</b>), for instance, mounted on the outboard side (e.g., <b>262</b>) of the right wall (e.g., <b>252</b>) at the motor shaft hole (e.g., relief <b>91</b>) in the right wall (e.g., <b>252</b>) and having a rotatable motor shaft (e.g., <b>72</b>).

p-0064Moreover, such a powertrain (e.g., <b>15</b>) may include a left drive pulley (e.g., <b>41</b>) located on the inboard side (e.g., <b>331</b>) of the left wall (e.g., <b>251</b>) and rotatably attached to the rotatable motor shaft (e.g., <b>71</b>) of the left motor (e.g., <b>151</b>) through the motor shaft hole (e.g., relief <b>91</b>) in the left wall (e.g., <b>251</b>). Further, such a powertrain (e.g., <b>15</b>) may include a right drive pulley (e.g., <b>42</b>) located on the inboard side (e.g., <b>232</b>) of the right wall (e.g., <b>252</b>) and rotatably attached to the rotatable motor shaft (e.g., <b>72</b>) of the right motor (e.g., <b>152</b>) through the motor shaft hole (e.g., relief <b>91</b>) in the right wall (e.g., <b>252</b>). Still further, various embodiments may include a left driven pulley (e.g., <b>43</b>) located on the inboard side (e.g., <b>331</b>) of the left wall (e.g., <b>251</b>) at the drive shaft hole (e.g., relief <b>92</b>) in the left wall (e.g., <b>251</b>), and a right driven pulley (e.g., <b>44</b>) located on the inboard side (e.g., <b>232</b>) of the right wall (e.g., <b>252</b>) at the drive shaft hole (e.g., relief <b>92</b>) in the right wall (e.g., <b>252</b>). In a number of embodiments, left driven pulley <b>43</b> and right driven pulley <b>44</b> may have a common centerline, for example. Even further still, such a powertrain (e.g., <b>15</b>) may include a left drive shaft (e.g., <b>21</b>), for example, rotatably attached to left driven pulley <b>43</b> through the drive shaft hole (e.g., relief <b>92</b>) in the left wall (e.g., <b>251</b>) and extending away from the left wall (e.g., <b>251</b>) on the outboard side (e.g., <b>261</b>) of the left wall (e.g., <b>251</b>). Such a drivetrain (e.g., <b>15</b>) may further include a right drive shaft (e.g., <b>22</b>), for instance, rotatably attached to right driven pulley <b>44</b> through the drive shaft hole (e.g., relief <b>92</b>) in the right wall (e.g., <b>252</b>) and extending away from the right wall (e.g., <b>252</b>) on the outboard side (e.g., <b>262</b>) of the right wall (e.g., <b>252</b>).

p-0065Furthermore, such a powertrain (e.g., <b>15</b>) obtained or provided in such a method (e.g., <b>100</b>, for instance, in act <b>101</b>) may further include a left drive belt (e.g., <b>31</b>) on the inboard side (e.g., <b>331</b>) of the left wall (e.g., <b>251</b>) and extending around left drive pulley <b>41</b> and extending around left driven pulley <b>43</b> so as to rotatably connect left drive pulley <b>41</b> to left driven pulley <b>43</b>. Similarly, such a powertrain (e.g., <b>15</b>) may include a right drive belt (e.g., <b>32</b>) on the inboard side (e.g., <b>232</b>) of the right wall (e.g., <b>252</b>) and extending around right drive pulley <b>42</b> and extending around right driven pulley <b>44</b> so as to rotatably connect right drive pulley <b>42</b> to right driven pulley <b>44</b>. Additionally, in such embodiments, the powertrain (e.g., <b>15</b>) may include a central wall (e.g., <b>29</b>) between the left wall (e.g., <b>251</b>) and the right wall (e.g., <b>252</b>). In a number of embodiments, for example, central wall <b>29</b> is between left drive pulley <b>41</b> and right drive pulley <b>42</b>, central wall <b>29</b> is between left driven pulley <b>43</b> and right driven pulley <b>44</b>, and central wall <b>29</b> is between left drive belt <b>31</b> and right drive belt <b>32</b>. Moreover, in a number of such embodiments, left driven pulley <b>43</b> is supported (e.g., as described herein) from both the left wall (e.g., <b>251</b>) and central wall <b>29</b>, and right driven pulley <b>44</b> is supported from both the right wall (e.g., <b>252</b>) and central wall <b>29</b>.

p-0066Still further, in a number of such methods (e.g., <b>100</b>), the electric powertrain (e.g., <b>15</b>) may include a left side adjustable tensioner (e.g., <b>36</b>), for example, on the inboard side (e.g., <b>331</b>) of the left wall (e.g., <b>251</b>), that adjustably presses a tensioner pulley (e.g., <b>38</b>) against left drive belt <b>31</b> between left drive pulley <b>41</b> and left driven pulley <b>43</b>. Similarly, such a powertrain (e.g., <b>15</b>) may include a right side adjustable tensioner (e.g., <b>37</b>), for instance, on the inboard side (e.g., <b>232</b>) of the right wall (e.g., <b>252</b>), that adjustably presses a tensioner pulley (e.g., <b>39</b>) against right drive belt <b>32</b> between right drive pulley <b>42</b> and right driven pulley <b>44</b>. Such a powertrain (e.g., <b>15</b>) may further include multiple joining walls (e.g., <b>351</b>-<b>356</b>, as shown in <figref idrefs="DRAWINGS">FIG. 3</figref>) extending from the left side wall (e.g., <b>251</b>) to the right side wall (e.g., <b>252</b>), for example, and holding the left side wall (e.g., <b>251</b>) in rigid relation to the right side wall (e.g., <b>252</b>).

p-0067Even further, in the embodiment illustrated, method <b>100</b> further includes act <b>102</b> of manufacturing, obtaining, or providing universal joints (e.g., constant velocity joints) in the drive shafts. For example, in act <b>102</b>, two universal joints (e.g., <b>23</b> and <b>27</b>) may be provided in the left drive shaft (e.g., <b>21</b>), and two universal joints (e.g., <b>24</b> and <b>28</b>) may be provided in the right drive shaft (e.g., <b>22</b>). Further still, method <b>100</b>, in the embodiment shown, includes act <b>103</b> of manufacturing, obtaining, or providing various wheels (e.g., road wheels of vehicle <b>10</b>). For example, act <b>103</b> may include manufacturing, obtaining, or providing a left first wheel (e.g., <b>11</b> shown in <figref idrefs="DRAWINGS">FIG. 1</figref>), for example, rotatably attached to the left drive shaft (e.g., <b>21</b>) at a first end (e.g., <b>191</b>, for example, the front) of the vehicle (e.g., <b>10</b>), and a right second wheel (e.g., <b>12</b>), for instance, rotatably attached to the right drive shaft (e.g., <b>22</b>) at the first end (e.g., <b>191</b>) of the vehicle (e.g., <b>10</b>). Further still, in some embodiments, act <b>103</b> may include manufacturing, obtaining, or providing a left third wheel (e.g., <b>13</b>) at a second end (e.g., <b>192</b>, for example, the rear) of the vehicle (e.g., <b>10</b>), and a right fourth wheel (e.g., <b>14</b>) at the second end (e.g., <b>192</b>) of the vehicle (e.g., <b>10</b>). Moreover, in the embodiment illustrated, method <b>100</b> further includes act <b>104</b> of manufacturing, obtaining, or providing a battery (e.g., <b>16</b> shown in <figref idrefs="DRAWINGS">FIG. 1</figref>) powering the left electric motor (e.g., <b>151</b>) and the right electric motor (e.g., <b>152</b>).

p-0068Various methods may further include acts of manufacturing, obtaining, providing, or making various components described herein or known in the art. Various methods in accordance with different embodiments include acts of selecting, making, positioning, or using certain components, as examples. Other embodiments may include performing other of these acts on the same or different components, or may include fabricating, assembling, manufacturing, obtaining, providing, ordering, receiving, shipping, or selling such components, or other components described herein or known in the art, as other examples. Further, various embodiments include various combinations of the components, features, and acts described herein or shown in the drawings, for example. Further, particular embodiments include various means for accomplishing one or more of the particular functions described herein or apparent from the structure described. Other embodiments may be apparent to a person of ordinary skill in the art having studied this document.