Abstract:
A vehicle is provided. The vehicle comprises an axle having a longitudinal dimension along a first axis, the axle coupled to at least one wheel, and a motor coupled to the axle and adapted to turn the axle, the motor adapted to rotate around a second axis, wherein the motor is oriented such that the first axis is substantially perpendicular to the second axis.

Description:
TECHNICAL FIELD 
       [0001]    Embodiments of the subject matter described herein relate generally to electric motors for vehicles. More particularly, embodiments of the subject matter relate to positioning of axial motors for vehicles. 
       BACKGROUND 
       [0002]    Vehicles, including electric and hybrid-electric vehicles, typically use a motor to rotate an axle coupled to two wheels for locomotion. The motor is typically co-axial with the axle. Electrical power is typically used to rotate a rotor of the motor, which, in turn, rotates the axle. The turning of the axle causes the wheels to rotate, which in turn propels the vehicle in the desired direction. 
         [0003]    A motor which is co-axial with the axle turning wheels of the vehicle has inherent limitations. For example, the outer radius of the motor is limited by the clearance of the axle above the ground. Consequently, the moment arm of the motor is limited by the outer radius of the motor, which affects the maximum torque which can be produced by the motor. 
         [0004]    As another example, co-axial placement of the motor results in a relatively large number of driveline components, which increases the complexity of the assembly. A large number of components can be relatively more difficult to maintain and repair than a smaller number of components. 
       BRIEF SUMMARY 
       [0005]    A vehicle is provided. The vehicle comprises an axle having a longitudinal dimension along a first axis, the axle coupled to at least one wheel, and a motor coupled to the axle and adapted to turn the axle, the motor adapted to rotate around a second axis, wherein the motor is oriented such that the first axis is substantially perpendicular to the second axis. 
         [0006]    A drive system for a vehicle is also provided. The drive system comprises an axle having a long dimension along a first axis, a motor having a rotating member adapted to rotate around a second axis, the motor oriented such that the first axis is substantially perpendicular to the second axis, and a shaft coupling the motor and the axle, the motor offset from the axle along the second axis, the shaft adapted to transmit power from the motor to the axle. 
         [0007]    Another drive system for a vehicle is provided. The drive system comprises an axle having a longitudinal dimension along a first axis, a motor adapted to rotate around a second axis, wherein the motor is oriented such that the second axis is substantially perpendicular to the first axis, the second axis offset from the first axis, a shaft coupling the motor and the axle, the motor offset from the axle along the second axis by the shaft, the shaft adapted to transmit power from the motor to the axle, and a gear assembly coupling the shaft to the axle, the gear assembly adapted to transmit power from the shaft to the axle. 
         [0008]    This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    A more complete understanding of the subject matter may be derived by referring to the detailed description and claims when considered in conjunction with the following figures, wherein like reference numbers refer to similar elements throughout the figures. 
           [0010]      FIG. 1  is a perspective view of an embodiment of a vehicle having a horizontally mounted motor; 
           [0011]      FIG. 2  is a side view of a detailed portion of the embodiment of  FIG. 1 ; 
           [0012]      FIG. 3  is a perspective view of the motor assembly of  FIG. 1 ; 
           [0013]      FIG. 4  is a cross-sectional view of the embodiment of  FIG. 3  as viewed from the line  4 - 4 ; 
           [0014]      FIG. 5  is a cross-sectional view of another embodiment of a horizontally mounted motor assembly; 
           [0015]      FIG. 6  is a side view of an embodiment of a vehicle having an offset motor extending in a rearward direction; and 
           [0016]      FIG. 7  is a side view of an embodiment of a vehicle having an offset motor extending in a forward direction. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    The following detailed description is merely illustrative in nature and is not intended to limit the embodiments of the subject matter or the application and uses of such embodiments. As used herein, the word “exemplary” means “serving as an example, instance, or illustration.” Any implementation described herein as exemplary is not necessarily to be construed as preferred or advantageous over other implementations. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description. 
         [0018]    “Coupled” —The following description refers to elements or nodes or features being “coupled” together. As used herein, unless expressly stated otherwise, “coupled” means that one element/node/feature is directly or indirectly joined to (or directly or indirectly communicates with) another element/node/feature, and not necessarily mechanically. Thus, although the schematic shown in FIG.  1 —depicts one exemplary arrangement of elements, additional intervening elements, devices, features, or components may be present in an embodiment of the depicted subject matter. 
         [0019]    “Adjust” —Some elements, components, and/or features are described as being adjustable or adjusted. As used herein, unless expressly stated otherwise, “adjust” means to position, modify, alter, or dispose an element or component or portion thereof as suitable to the circumstance and embodiment. In certain cases, the element or component, or portion thereof, can remain in an unchanged position, state, and/or condition as a result of adjustment, if appropriate or desirable for the embodiment under the circumstances. In some cases, the element or component can be altered, changed, or modified to a new position, state, and/or condition as a result of adjustment, if appropriate or desired. 
         [0020]    “Inhibit” —As used herein, inhibit is used to describe a reducing or minimizing effect. When a component or feature is described as inhibiting an action, motion, or condition it may completely prevent the result or outcome or future state completely. Additionally, “inhibit” can also refer to a reduction or lessening of the outcome, performance, and/or effect which might otherwise occur. Accordingly, when a component, element, or feature is referred to as inhibiting a result or state, it need not completely prevent or eliminate the result or state. 
         [0021]    In addition, certain terminology may also be used in the following description for the purpose of reference only, and thus are not intended to be limiting. For example, terms such as “upper”, “lower”, “above”, and “below” refer to directions in the drawings to which reference is made. Terms such as “front”, “back”, “rear”, “side”, “outboard”, and “inboard” describe the orientation and/or location of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. 
         [0022]    As used herein, a co-axial motor means one having an axis of rotation coinciding with the axis of rotation of the axle. Thus, such a motor can be positioned on and extend radially outward from the axle. Such a co-axial motor can be located between two wheels of the vehicle, at any point along the axle, including a central position. 
         [0023]      FIG. 1  illustrates an embodiment of a vehicle  100  having a horizontally mounted motor  110  coupled to an axle  130  supporting two wheels  150 .  FIG. 2  illustrates a detailed side view of a portion of the vehicle  100 . The horizontally mounted motor  110  can have several advantages over a co-axial motor situated vertically along the axle  130 . Because the horizontally mounted motor  110  does not extend radially outward in a direction toward the ground, the outer diameter of the motor  110  is not limited by clearance of the vehicle  100  over the ground. Accordingly, the outer diameter of a horizontally mounted motor  110  can be larger by any amount desired and/or appropriate for the embodiment. A larger diameter motor  110  can have a larger moment arm resulting in increased torque. Additionally, the increased torque can be accomplished with a lower force, resulting in weight reduction for certain components. These advantages are in addition to those described below. 
         [0024]    The vehicle  100  of the illustrated embodiment is a hybrid-electric automobile. In other embodiments, other vehicles can be have one or more of the features described herein, including, without limitation, electric automobiles, all-terrain vehicles, trucks, and sport utility vehicles. The vehicle  100  can have one or more wheels  150  coupled together, supported by, and driven by the axle  130 . The wheels  150  depicted as drive wheels are the rear wheels of the vehicle  100  in the illustrated embodiment. In other embodiments, the front wheels can be used, as desired. 
         [0025]    The axle  130  preferably extends between the wheels  150 . The axle  130  can be a solid component, or can contain one or more rotating flexible axle shafts  134  coupled to the wheels  150  as desired. The axle shaft  134  can be the component of the axle  130  which actually rotates and transmits power to the wheels  150 . The axle  130  can extend to both wheels  150 , as shown. In certain embodiments, the axle  130  can extend to only one wheel  150 , while the other is independently suspended and/or supported. In such embodiments, the motor  110  can provide power only to the wheel coupled to the axle, while the other wheel is free to rotate. 
         [0026]    Although the illustrated embodiment of the vehicle  100  depicts the motor  110  coupled to an axle  130  situated to the rear of the vehicle, in certain embodiments, the motor  110  can be coupled to a front axle of a vehicle. In such embodiments, the motor  110  can be adapted to transmit power through the front axle to the front wheels. Thus, any of the features described herein can be equally applicable to front wheel driven vehicles, as well as the rear wheel embodiments depicted. Therefore, an “axle” can be either a front or rear axle, depending on the desired embodiment. The motor  110  can be positioned relative to the axle  130  as described below, regardless of whether the axle is the front axle of a four vehicle or the rear axle. 
         [0027]    The wheels  150  can be any type of wheel appropriate to the embodiment. With additional reference to  FIG. 3 , a detailed perspective view of the motor assembly  116  with certain components of the vehicle  100  omitted for clarity. As can be seen, the wheels  150  can be coupled to the axle  130  with a bearing assembly  152 . The wheels  150  can additionally be coupled to the axle shaft  134  to receive a rotating force therefrom. The wheel  150  can have any desired size or configuration sufficient to rotate in response to the force from the axle shaft  134 , thereby propelling the vehicle  100 . 
         [0028]    The motor  110  can be coupled to the axle  130 , including the axle shaft  134  in any desired manner. The motor  110  can be any motor which generates rotational force for a central shaft, including those motors having a substantially circular shape, such as in the illustrated embodiment. Such motors are commonly known as pancake motors, although other names and designations can be used. The motor  110  can be an electric motor of any desired type, including without limitation, an axial flux motor. 
         [0029]    The motor  110  can comprise one or more components rotating about a central axis, including rotors, as well as stationary components, such as a stator. Additionally, other components, including bearing assemblies, a resolver, gear assemblies, and so on, can cooperate with or be included with the motor  110 . The motor  110  can include rotors and/or stators with one or more spokes radiating from the central axis. The spokes can be composed of any appropriate material, including metals, as well as lighter-weight materials, such as carbon fiber materials. 
         [0030]    With additional reference to  FIG. 4 , a cross-sectional view of the motor assembly  116  is shown. The motor  110  can couple to the axle  130  at a coupling site  132 . The coupling site  132  can include one or more gears and/or gear assemblies which transmit power from the motor  110  to the axle shaft  134 . A coupling site  132  can include a right angle differential to transmit rotational power from the axis of generation by the motor  110  to a drive axis of the axle shaft  134 . The coupling between the motor  110  and axle shaft  134  can have any number of components, systems, or sub-assemblies necessary to perform the power transmission functions described herein. A shaft  112  can be present between the motor  110  and the coupling site  132 , as visible in  FIG. 4 . In certain embodiments, the shaft  112  can be omitted, and the motor  110  can be coupled directly to the coupling site  132 . The coupling site  132  and central motor axis  111  can be at the center of the axle  130 , or offset from the center in either direction, as desired. 
         [0031]    As shown, the circular motor  110  can have a central motor axis  111  about which its internal components rotate, and around which power is generated. Similarly, the axle  130  can have a central axle axis  131  along its long dimension. The central axle axis  131  can be substantially parallel to flat, level ground beneath the vehicle  100 . In typical motor assemblies, the motor and axle share a common central axis, known as a co-axial arrangement. By contrast, the central motor axis  111  can be substantially perpendicular to the central axle axis  131 , as shown. In certain embodiments, including the illustrated embodiment, the central motor axis  111  can be substantially parallel to the downward direction of gravity when the vehicle  100  is on flat, level ground. As used herein, the indicator/is used to show the level of flat, level ground, while the indicator g is used to indicate the downward direction of gravity. The vehicle  100  can have a bottom plane  199  substantially parallel to the level of flat, level ground. The bottom plane  199  can be formed by one or more components, such as a body pan. The bottom plane  199  need not be a literal plane, and instead refers to the substantially planar shape of the underside of a vehicle. 
         [0032]    Additionally, a substantially perpendicular direction does not require that two components intersect, or that any intersection occur at exactly 90°. Rather, two directions can be substantially perpendicular if they do not intersect, but the angle formed between the two directions when projected to a plane containing either direction is about 90°. Thus, two lines which extend in directions separated by 85° can be considered substantially perpendicular. Directions which form as angles greater than 85° can be considered substantially perpendicular as well. Substantially parallel directions are similar in that they can form a small non-zero angle of approximately 5° or less while still being considered substantially parallel. 
         [0033]    As described above, because the motor  110  is mounted along an axis of rotation substantially perpendicular to the axis of rotation of the axle shaft  134 , it is not constrained in a radial outward direction of the motor  110  by the clearance of the vehicle  100  above the ground. Accordingly, the motor  110  can advantageously have a larger size. For example, where a co-axial motor in the prior art typically has an outer diameter of between 12 and 15 inches, a horizontally mounted motor, such as the motor  110  of the motor assembly  116 , can have an outer diameter of 24 inches, or larger, as desired. In certain embodiments of the motor  110 , the same force as a similar co-axial motor can be used to generate torque, resulting in a torque greater than that of a similar co-axial motor. In other embodiments, a force comparatively smaller than that of a similar co-axial motor can be used to generate torque which is still comparatively larger than that of a similar co-axial motor. The lower force is sufficient because of the increased outer diameter, resulting in a larger moment arm. Because a comparatively lower force is used, however, the required strength of the components of the motor  110  can be reduced. As a result, components composed of lighter-weight material can be used, while still providing the required strength. For example, one or more of the components of the motor  110  can be composed of a composite and/or ceramic material, if desired. 
         [0034]    With reference to  FIG. 5 , another embodiment of a motor assembly  316  is shown. Unless otherwise mentioned, the components of  FIG. 5  are substantially similar to those described above with reference to  FIGS. 1-4 , except that the indicators have been incremented by 200. 
         [0035]    The central motor axis  311  can be offset from the central axle axis  331 , as shown. Unlike the embodiment of  FIGS. 1-4 , the central motor axis  311  and central axle axis  331  do not intersect, and the central motor axis  311  does not extend through the central axle axis  331 . This is because the motor  310  is offset from the center of the axle  330 , as shown. Accordingly, the shaft  312  extending along the central motor axis  311  is coupled to the coupling site  332  via an extension portion  336 . 
         [0036]    The extension portion  336  can receive the shaft  312 , including any rotating components transmitting power from the motor  310 . The coupling site  332  can include one or more gear assemblies adapted to transmit power from the motor  310  to the axle shaft  334  through the extension portion  336  and the remainder of the coupling site  332 . As with the embodiment of  FIGS. 1-4 , the coupling between the motor  310  and axle shaft  334  can have any number of components, systems, or sub-assemblies necessary to perform the power transmission functions described herein. 
         [0037]    As shown, the central motor axis  311  can still be substantially parallel to the downward direction of gravity and substantially perpendicular to the central axle axis  331 . The length of the shaft  312  can vary between embodiments, from being omitted entirely to any desired length. 
         [0038]      FIG. 6  illustrates another embodiment of the vehicle  400 . Unless otherwise mentioned, the components of  FIG. 6  are substantially similar to those described above with reference to  FIGS. 1-4 , except that the indicators have been incremented by 300. In the embodiment of  FIG. 6 , a motor  410  is coupled to an axle  430  such that the central motor axis  411  forms an acute angle with the direction of flat and level ground l 1 . The angle between the central motor axis  411  and flat, level ground l 1  can be any desired angle between 0° and 90°. As a result, the shaft  412  coupling the motor  410  to the coupling site  432  can extend at an angle towards the rear  402  of the vehicle  400 . Consequently, the motor  410  is positioned closer to the rear  402  of the vehicle  400  than the axle  430  is. The distance of the motor  410  from the axle  430  can be increased by increasing the length of the shaft  412 . Accordingly, the position of the motor  410  can be adjusted to any desired rearward position. In certain embodiments, the motor  410  can be positioned against the rear exterior of the vehicle  400 , enhancing rear performance. 
         [0039]    Moreover, in certain embodiments, an angle can be formed between the central motor axis  411  and the central axle axis  431 , if desired. Thus, the motor  410  can “lean” toward either wheel by any desired number of degrees, subject to the physical constraints of the motor  410 . The coupling site  432  can include features required to redirect the rotational force to the shaft  412 . 
         [0040]      FIG. 7  illustrates another embodiment of the vehicle  500 . Unless otherwise mentioned, the components of  FIG. 7  are substantially similar to those described above with reference to  FIGS. 1-4  and  6  except that the indicators have been incremented by 400 and 100, respectively. In the embodiment of  FIG. 7 , a motor  510  is coupled to an axle  530  such that the central motor axis  511  forms an acute angle with the direction of flat and level ground l 2 . Unlike  FIG. 6 , the shaft  512  extends toward the front  504  of the vehicle  500 , positioning the motor  510  closer to the front  504  of the vehicle  500  than the axle  530  is positioned. The length of the shaft  512  can be varied to any desired amount, adjusting both the distance between the motor  510  and axle  530 , as well as the position within the vehicle  500  of the motor  510 . In certain embodiments, the motor  510  can be positioned adjacent one or more rear seats  506  of the vehicle  500 . 
         [0041]    With reference back to  FIG. 6 , the position of a motor within a vehicle can be selected, either forward or rearward of the axle. The position of the motor  510  can be selected to adjust the weight characteristics of the vehicle  500 . It is desirable for a vehicle to have weight evenly distributed between the front and rear wheels. By adjusting the length of the shaft  512 , as well as the forward or rearward projection of the shaft  512 , the weight distribution of the vehicle  500  over the wheels can be adjusted. Such adjustment of position is another advantage of an axially offset motor over a co-axial motor. 
         [0042]    While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or embodiments described herein are not intended to limit the scope, applicability, or configuration of the claimed subject matter in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the described embodiment or embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope defined by the claims, which includes known equivalents and foreseeable equivalents at the time of filing this patent application.