Patent Publication Number: US-2013241366-A1

Title: High torque/high efficiency winding motor

Description:
CLAIM OF PRIORITY 
     This application claims priority to Provisional Application No. 61/603,881 filed on Feb. 27, 2012 and to Provisional Application No. 61/603,883 filed on Feb. 27, 2012. 
    
    
     FIELD OF THE INVENTION 
     Embodiments of the invention generally pertain to transportation vehicles, and more particularly to motors utilized in transportation vehicles. 
     BACKGROUND 
     As the demand increases for alternative vehicles such as hybrid, electric, and fuel cell vehicles, existing technical solutions have become limiting factors in the efficiency of vehicle design. For example, in hybrid vehicles, an electrical motor is used for low-speed conditions when high amounts of torque are needed, while a separate gas engine is used in high-speed conditions when engine efficiency is desired. The use of two engines increases the space needed for the vehicle&#39;s power solution, thereby decreasing the interior volume of the vehicle. 
     Furthermore, as the demand increases for higher efficiency vehicles, it becomes important to minimize vehicle weight and maximize vehicle interior volume. Current solutions to decrease vehicle drivetrain volume tend to significantly degrade vehicle handling, decrease corner entrance and exit speeds and reduce traction in inclement environmental conditions such as rain or snow. What is needed is a solution to decrease the volume necessary for a vehicle&#39;s drivetrain, while also increasing the potential for vehicle interior volume and vehicle maneuverability. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Non-limiting and non-exhaustive embodiments of the invention are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified. It should be appreciated that the following figures may not be drawn to scale. 
         FIG. 1A  is an illustration of a rotor and stator assembly according to an embodiment of the invention. 
         FIG. 1B  is an illustration of prior art stator assemblies. 
         FIG. 2  is an illustration of a rotor and stator assembly according to an embodiment of the invention. 
         FIG. 3  illustrates an inline two-wheeled vehicle incorporating one or more an embodiments of the invention. 
         FIG. 4A  and  FIG. 4B  illustrate a drive wheel motor according to an embodiment of the invention. 
         FIG. 5A-FIG .  5 D illustrate a drive wheel motor according to an embodiment of the invention. 
     
    
    
     Descriptions of certain details and implementations follow, including a description of the figures, which may depict some or all of the embodiments described below, as well as a discussion of other potential embodiments or implementations of the inventive concepts presented herein. An overview of embodiments of the invention is provided below, followed by a more detailed description with reference to the drawings. 
     DESCRIPTION 
     Embodiments of the invention describe methods, systems and apparatuses utilizing a motor having a rotor assembly and a stator assembly to rotatably drive the rotor assembly to multiple variable operating ranges. 
     In the following description numerous specific details are set forth to provide a thorough understanding of the embodiments. One skilled in the relevant art will recognize, however, that the techniques described herein can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring certain aspects. 
       FIG. 1A  is an illustration of a rotor and stator assembly according to an embodiment of the invention.  FIG. 1A  illustrates rotor assembly  150  to rotate around (i.e., external to) stator assembly  100 . Said stator assembly includes body  102  and a plurality of teeth (alternatively referred to herein as stator poles) extending radially outward from the body. In this example, said plurality of teeth is shown comprise teeth  110 - 115  and teeth  120 - 125 . 
     Motors utilizing rotating and stationary components, such as rotor assembly  150  and stator assembly  100 , may use a magnetic field to convert electrical energy into mechanical energy according to the motor principle or to convert mechanical energy into electrical energy according to the generator principle. 
     For example, a stator component of an electrical motor may comprise of a stack of metal plates, forming a yoke and a number of teeth. In the slots between these teeth, an electrical winding may be provided, which comprises of a number of coils. When current flows through this winding, it produces the magnetic field of the electrical motor. The rotor component of said electrical motor may comprise, for example, of a stack of plates, on which a number of magnets (e.g., permanent magnets) are mounted. 
     In this embodiment, stator assembly  100  includes and at least two winding sets, each winding set comprising coils wound on the teeth of the stator assembly. As shown in  FIG. 1A , the windings on teeth  110 - 115  comprise a first set for driving rotor assembly  150  to a first variable operational range, and the windings on teeth  120 - 125  comprise a second set for driving rotor assembly  150  to a second variable operational range different than the first. 
     In this example, the first set of windings comprises a first number of coils wound on teeth  110 - 115 , and the second set of windings comprises a second number of coils, less than the first number, wound on teeth  120 - 125 . The first and second sets of windings are also shown to be wound on alternating teeth of stator assembly  100 . 
     In some embodiments, the above described first and second variable operational ranges comprise rotor speeds (e.g., the first range may be for 0-500 RPMs, while the second range may be for 500+ RPMs). In other embodiments, the first and second operational ranges comprise power efficiency ranges (e.g., the power-in/power-out percentage of the first range may be 85%, while the power-in/power-out percentage of the second range may be 90%). 
     In some embodiments, stators have redundant windings to ensure operation of the electrical motor in the event of a failure or one of the windings. For example, in  FIG. 1A , the coils wound on teeth  120 - 125  are shown to include a redundant set—e.g., redundant winding  125 A on tooth  125 . In other embodiments, said redundant windings may comprise another winding set on a separate tooth. 
     In some embodiments, stator assembly  100  and rotor assembly  150  may be used in a flywheel motor in vehicular energy storage applications having multiple operating modes. Each of these modes has different requirements and creating an appropriate singular design in order to meet all of these modes does not exist in prior art solutions (i.e., separate stator assemblies, such as prior art stators  190  and  195  of  FIG. 1B  would have to be utilized; however, in some embodiments of the invention, stator assemblies such as stators  190  or  195  comprise the above described redundant set of windings). The different sets of windings on teeth  110 - 115  and  120 - 125  comprises more than one set of coil windings, each with different parameters to allow for better meeting each of these modes. 
     For example, one mode may be a start-up/energy injection/energy recovery mode (i.e., the mode accomplished by the windings similar to that on prior art stator assembly  195  and on teeth  120 - 125  of stator assembly  100 ). The requirements for optimal work in this mode include the ability to transmit very large amounts of power quickly. One way of achieving this is to use larger diameter wires with fewer turns per stator pole/teeth. A second mode is a low power, high speed, low change mode. For this mode, smaller diameter wires with more windings may be optimal (i.e., by windings similar to that on prior art stator assembly  190  and on teeth  110 - 115  of stator assembly  100 ). In some embodiments, multiple modes may be formed on a wheel having a quantity of stator teeth divisible by six (e.g., twelve stator teeth for two modes of operation, as shown in motor  100 , eighteen stator teeth for three modes of operation, etc.). There are other possible modes besides the above described example, and a level of granularity in other embodiments may be achieved by using multiple sets of windings around the same stator teeth, or by having non-connected sets around adjacent or non-adjacent teeth. 
       FIG. 2  is an illustration of a rotor and stator assembly according to an embodiment of the invention. In this embodiment, rotor assembly  250  is configured to rotate within (i.e., internal to) stator assembly  200 . Said stator assembly includes body  202 , a plurality of teeth (alternatively referred to herein as stator poles) extending radially inward from the body. In this example, said plurality of teeth is shown comprise teeth  210 - 215  and teeth  220 - 225 . 
     In this embodiment, stator assembly  200  includes and at least two winding sets, each winding set comprising coils wound on the teeth of the stator assembly. As shown in  FIG. 2 , the windings on teeth  210 - 215  comprise a first set for driving rotor assembly  250  to a first variable operational range, and the windings on teeth  220 - 225  comprise a second set for driving rotor assembly  250  to a second variable operational range different than the first. 
     In this example, the first set of windings comprises a first number of coils wound on teeth  210 - 215 , and the second set of windings comprises a second number of coils, less than the first number, wound on teeth  220 - 225 . The first and second sets of windings are also shown to be wound on alternating teeth of stator assembly  200 . Other embodiments may include more than two sets of different windings, multiple sets of windings around the same stator teeth, or by having non-connected sets around adjacent or non-adjacent teeth. 
       FIG. 3  illustrates an inline two-wheeled vehicle incorporating one or more embodiments of the invention. In this embodiment, vehicle  300  comprises vehicle frame  302 , and further includes first and second drive wheels  310  and  320 . First and second drive wheels motor generators  312  and  322  are coupled to drive wheels  310  and  320 , respectively, through drive chains  314  and  324 , respectively. In alternative embodiments, said drive wheel motors may comprise in-wheel hub motors that do not use said drive chains. Drive wheel motor generators may each comprise a motor having an embodiment of the rotor and stator assemblies described above. 
     In this embodiment, gyro stabilizing unit  330  is coupled to vehicle  300  through vehicle frame  302 . Gyro stabilizer  330  may include first and second gyro assemblies housing flywheels  332  and  334 ; said flywheels may differ in size and material composition, or may be substantially identical. Said first and second gyro assemblies may further house flywheel motor-generators to drive their respective flywheels. These flywheel-motor generators may each comprise a motor having an embodiment of the rotor and stator assemblies described above. 
     In this embodiment, vehicle  300  further includes an energy storage unit having battery bank  340 , capacitor bank  342 , and a power switching circuit in electrical communication with battery bank  340 , capacitor bank  342 , and any of the above described drive wheel motor-generators and flywheel motor-generators having an embodiment of the rotor and stator assemblies described above. The power switching circuitry may control the multiple operating modes of the motors utilizing rotor and stator assemblies according to embodiments of the invention—e.g., vehicular energy storage applications utilizing the multiple operating modes enabled by said stator assemblies. In other embodiments, said power switching circuitry may comprise digital logic, a processor-executed software module stored on a computer readable medium, or any combination of circuitry, logic and modules. 
     Embodiments of the invention describe methods, systems and apparatuses utilizing a wheel hub to include a wheel and a motor included in the wheel hub to transmit power to the wheel. As described below, embodiments of the invention decrease vehicle drivetrain volume and increase the potential for vehicle interior volume, while not adversely affecting vehicle maneuverability. 
       FIG. 4A  and  FIG. 4B  illustrate a drive wheel motor according to an embodiment of the invention. In this embodiment, apparatus  400  is shown in  FIG. 4  to include wheel  402 , wheel hub  404 , and swing arm assembly  406  coupled to the wheel and the wheel hub. In this embodiment, wheel  402  comprises a rear wheel of a vehicle; in other similar embodiments, wheel  402  may comprise a front wheel of a vehicle. Swing arm assembly  406  is shown to couple to a vehicle frame is an oscillating manner, allowing a user to “turn” rear wheel  402 —i.e., the rear wheel moves in response to a vehicle&#39;s steering system. Thus, vehicle maneuverability is significantly increased by having the rear wheel turn in conjunction with any front wheel maneuverability (e.g., swing arm assembly  406  allows for corrective steering capability). 
     In this embodiment, wheel hub  404  is shown to include motor  410  included in the wheel hub to transmit power to wheel  402 . While illustrated to apply force to a single wheel, in other embodiments, a drive wheel motor may be configured to apply force to a plurality of wheels (e.g., an embodiment where swing arm assembly comprises a double-sided swing arm assembly, having a wheel on each side).  FIG. 4B  illustrates the components of motor  410 , including axle  412 , axle case  414 , stator  416  and rotor  418 . Axle case  414  is fixedly secured to swing arm  406 , and axle  412  is rotatably supported in the axle case through bearing members (not shown). 
     In this embodiment, stator  416  and rotor  418  are shown to generate the rotational force applied to wheel  402 . For example, a stator component of an electric motor may comprise of a stack of metal plates, forming a yoke and a number of teeth. In the slots between these teeth, an electrical winding may be provided, which comprise of a number of coils. When current flows through this winding, it produces the magnetic field of the electric motor, which causes the rotor assembly to rotate. The rotor component of said electric motor may comprise, for example, of a stack of plates, on which a number of magnets (e.g., permanent magnets) are mounted. Power transmission member  420  is shown to provide a controlled application of the rotational power of motor  410  to wheel  402 . 
     Thus, in this embodiment, by allowing the rear wheel to turn in response to a vehicle&#39;s steering system, vehicle maneuverability is significantly increased. Furthermore, having motor  410  included in wheel hub  404  allows the vehicle drive motor system to not adversely affect the interior volume of the vehicle. 
       FIG. 5A-FIG .  5 D illustrate a drive wheel motor according to an embodiment of the invention. In this embodiment, a center hub steering mechanism with an integrated wheel hub motor (e.g., an electric motor) is shown to couple a front wheel to a vehicle frame. 
     As shown in  FIG. 5A , wheel  500  comprises a front wheel of a vehicle coupled to a vehicle frame via a center axle of hub motor and steer assembly  510 ; in other similar embodiments, wheel  500  may comprise a rear of a vehicle. As described below, in this embodiment the center axle does not spin; a wheel drive motor (described below) applies rotational force to front wheel  500 , and is coupled to the center axle via a plurality of bearings so as to not apply rotational force to the axle. Therefore, the center axle may be used for steering (and is thus alternatively referred to herein as a “steering axis”). 
     The hub of front wheel  500  is shown in the cross-sectional illustration of  FIG. 5B  to include hub motor and steer assembly  510  to apply rotational force to wheel  500 . Hub-center motor and steering systems according to embodiments of the invention use an arm, or arms, on bearings to allow upward wheel deflection integrated with the suspension system. The electric motor/generator windings and armature are part of the wheel and the hub which generates electricity. While illustrated to apply force to a single wheel, in other embodiments, said drive wheel motor may be configured to apply force to a plurality of wheels. Furthermore, as described below, embodiments of the invention may be further used as part of an energy recovery system for the vehicle. 
       FIG. 5C  illustrates hub motor and steer assembly  510  and suspension assembly  502 . In this embodiment, the braking system for wheel  500  is controlled via brake actuator module integrated into a cover/housing of suspension assembly  502 .  FIG. 5C  further illustrates cables  504 , which may comprise hub-motor cables and actuator module-to-actuator control unit (not shown) cables. Thus, suspension arm assembly  502  may comprise a suspension arm cover housing a plurality of power supply cables, brake/steering activator modules or redundant mechanical braking systems. 
       FIG. 5C  and  FIG. 5D  illustrate components  511 - 519  of hub motor and steer assembly  510 . In this embodiment, hub motor and steer assembly  510  is shown to include first suspension arm  511 , four bar linkage mount  512 , wheel bearing  513 , spindle cap  514 , spindle bearing  515 , hub spindle  516 , spindle cap  517 , electric motor  518  and second suspension arm  519 . Said suspension arms may also comprise the above described swing arms (e.g., swing arm assembly  106  of  FIG. 1 ). Electric motor  518  is shown to further comprise stator assembly  518 A, coils/power electronics/inverters  518 B, permanent magnets  518 C, and rotor  518 D. Said stator and rotor assemblies generate the rotational force to be applied to wheel  500 . A power transmission member (not shown) may be utilized to provide a controlled application of the rotational power of motor  510  to wheel  500 . 
     In some embodiments, in-hub electric motors such as the front and rear wheel embodiments discussed above may act as traction motor and part of the regenerative braking system in a two-wheeled, self-balancing vehicle (e.g., the vehicle described above and illustrated in  FIG. 3 ). In other embodiments, said electric motor may act solely as a traction motor. For all embodiments, the use of one or more in-hub electric motors significantly reduces the amount of space within a vehicle frame that is dedicated for drive motor storage without degrading vehicle handling, without adversely affecting corner entrance and exit speeds, and without reducing traction in inclement environmental conditions such as rain or snow. 
     Thus, in reference to  FIG. 3 , first and second drive wheels motor generators  312  and  322  may each be included in the hubs of drive wheels  310  and  320 , respectively, and may comprise any electric motor embodiments described above (and thus, not use drive chains  314  and  324 ). For example, drive wheel motor  322  may comprise the front wheel motor illustrated in  FIG. 5A-2D , and drive wheel motor  312  may comprise the steerable rear-wheel motor illustrated in  FIG. 4A-4B . 
     It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reading and understanding the above description. The scope of the disclosure should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. 
     Some portions of the detailed description above are presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is here, and generally, conceived to be a self-consistent series of operations leading to a desired result. The operations are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. 
     It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the discussion above, it is appreciated that throughout the description, discussions utilizing terms such as “capturing,” “transmitting,” “receiving,” “parsing,” “forming,” “monitoring,” “initiating,” “performing,” “adding,” or the like, refer to the actions and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (e.g., electronic) quantities within the computer system&#39;s registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices. 
     Embodiments of the disclosure also relate to an apparatus for performing the operations herein. This apparatus may be specially constructed for the required purposes, or it may comprise a general purpose computer selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a non-transitory computer readable storage medium, such as, but not limited to, any type of disk including floppy disks, optical disks, CD-ROMs, and magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs), EPROMs, EEPROMs, magnetic or optical cards, or any type of media suitable for storing electronic instructions. 
     Some portions of the detailed description above are presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is here, and generally, conceived to be a self-consistent sequence of steps leading to a desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. 
     It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the above discussion, it is appreciated that throughout the description, discussions utilizing terms such as “capturing”, “determining”, “analyzing”, “driving”, or the like, refer to the actions and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (e.g., electronic) quantities within the computer system&#39;s registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices. 
     The algorithms and displays presented above are not inherently related to any particular computer or other apparatus. Various general purpose systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct a more specialized apparatus to perform the required method steps. The required structure for a variety of these systems will appear from the description below. In addition, the present disclosure is not described with reference to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the disclosure as described herein. 
     Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout the above specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. 
     The present description, for purpose of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the disclosure to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the disclosure and its practical applications, to thereby enable others skilled in the art to best utilize the various embodiments with various modifications as may be suited to the particular use contemplated. 
     Methods and processes, although shown in a particular sequence or order, unless otherwise specified, the order of the actions may be modified. Thus, the methods and processes described above should be understood only as examples, and may be performed in a different order, and some actions may be performed in parallel. Additionally, one or more actions may be omitted in various embodiments of the invention; thus, not all actions are required in every implementation. Other process flows are possible.