Patent Publication Number: US-2011050153-A1

Title: Control mechanism for accelerating magnetically suspended rotor

Description:
RELATED APPLICATIONS 
     This application is related to and derives priority from US Provisional patent application entitled CONTROL MECHANISM FOR ACCELERATING MAGNETICALLY SUSPENDED ROTOR filed Aug. 25, 2008, which is incorporated herein by reference. 
     FIELD 
     The present invention is a system and method for controlling the acceleration of a propulsion apparatus comprising a rotor magnetically sustained within a stator. 
     BACKGROUND 
     A maglev, or magnetically levitating vehicle is a form of transportation that suspends, guides and propels vehicles (predominantly trains) using electromagnetic force. This method has the potential to be fast and quiet when compared to wheeled mass transit systems. 
     In electrodynamic suspension (EDS), both the rail and the vehicle exert a magnetic field, and the train is levitated by the repulsive force between these magnetic fields. The magnetic field in the vehicle is produced by either electromagnets or by an array of permanent magnets. The repulsive force in the rail is created by an induced magnetic field in wires or other conducting strips in the rail. 
     Propulsion coils on the rail are used to exert a force on the magnets in the vehicle and move the vehicle forward. The propulsion coils that exert a force on the vehicle are effectively a linear motor: An alternating current flowing through the coils generates a continuously varying magnetic field that moves forward along the rail. The frequency of the alternating current is synchronized to match the speed of the vehicle. The offset between the field exerted by magnets on the vehicle and the applied field create a force moving the vehicle forward. 
     Maglev concepts may have other applications, such as in magnetically suspended and propelled turbine devices, which will bring greater efficiency in reduction of friction and heat generation. However problems are encountered in the acceleration of magnetically suspended rotors due to unintended forces that disrupt equilibrium sustaining forces. 
     OBJECTS 
     With respect to the need for efficient rotary mechanisms, it is therefore an object and advantage of the present invention to perfect an apparatus that may be magnetically sustained and driven. 
     A first benefit of the invention is a rotor that may be magnetically accelerated while maintaining friction-free rotation. 
     A second benefit of the present invention is an apparatus wherein the rotor may be accelerated by pre-selected and controlled magnetic forces. 
     Other benefits and advantages of the invention will appear from the disclosure to follow. In the disclosure reference is made to the accompanying drawing, which forms a part hereof and in which is shown by way of illustration a specific embodiment in which the invention may be practiced. This embodiment will be described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural changes may be made in details of the embodiments without departing from the scope of the invention. 
     SUMMARY 
     The present invention is disclosed in an exemplary embodiment as a propulsion apparatus. The apparatus comprises the following components:
         1. A rotor rotating in a stator, the rotor magnetically maintained for rotation without friction by magnets situated in and on the rotor and stator.   2. Pairs of magnets fixed to the rotor and stator. The first magnet of each magnet pair is fixed at a rotor placement point and the second magnet of each magnet pair is fixed on the stator at a fixed stator point. The second magnet of each magnet pair is an electromagnet that is activated by a control device.   3. A vertical axis is defined such that the vertical axis passes through the center of rotation of the rotor.   4. Each stator placement point is a point on a first line defined by kα, where α is a divisor of 360 degrees. Each rotor placement point is a point on a second line that is rotated β with respect to the first line.   5. The control device selects m≧1 pairs of second magnets for activation to cause rotation of the rotor.   6. If the first of the second magnet pair activated is on a line at γ with respect to the vertical axis, the second of the second magnet pair is on a line at −γ with respect to the vertical axis.       

    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1A  illustrates the rotor that is magnetically sustained and moved within a stator. 
         FIG. 1B  illustrates the rotor that is magnetically driven within the stator. 
         FIG. 1C  shows a wheel attached to the rotor. 
         FIG. 1D  shows a propeller attached to the rotor. 
         FIG. 1E  illustrates the principles of contra-rotating propellers attached to the rotor. 
         FIG. 1F  shows two contra-rotating propellers attached to the rotor. 
         FIG. 1G  shows angular relationships of reference points used to place magnetic devices in the rotor and stator. 
         FIG. 1H  also shows angular relationships of reference points used to place magnetic devices in the rotor and stator. 
         FIG. 2  depicts a computing environment for the control logic for selecting magnetic devices to rotate the rotor within the stator. 
         FIG. 3  illustrates the configuration of magnetic devices energized in relationship to points of reference on the rotor and stator. 
         FIG. 4  is a logic diagram of the method for magnetically controlling the rotor. 
     
    
    
     DETAILED DESCRIPTION 
     An Exemplary Embodiment 
       FIG. 1A  shows an exemplary apparatus for practicing the invention, specifically a rotor  1100  magnetically sustained or suspended within a stator  1200 . Magnetic devices for sustaining the stator  1100  are not shown but are disclosed and described in another patent application. 
     Applications of the Invention 
     A traditional turbofan is a type of aircraft gas turbine engine that provides propulsion using a combination of a ducted fan and an jet exhaust nozzle. Part of the airstream from the ducted fan passes through the core, providing oxygen to burn fuel to create power. However, the rest of the air flow bypasses the engine core and mixes with the faster stream from the core. The rather slower bypass airflow produces thrust more efficiently than the high-speed air from the core, and this reduces the specific fuel consumption. 
     With reference to  FIG. 1B , the invention may replace a traditional turbofan jet (or hot combustion gas) driven engine with the rotor  1100  and stator as described above that is driven and controlled utilizing the magnetic devices disclosed. In  FIG. 1B , the rotor  1100  is configured with fan blades  1110  for engaging and propelling an airstream to produce thrust. 
     Now referring to  FIG. 1C , the apparatus of the invention may be used to propel a vehicle by means of a drive (and support) wheel  1120  attached to the rotor  1100 . 
     Further as shown in  FIG. 1D , the rotor  1100  may be configured to receive a propeller  1130  to produce lift over a wing surface and to provide forward momentum to an aircraft. 
     Refer to  FIG. 1E , wherein is shown a stator  1200  having two contra rotating rotors  1150  and  1160 . The rotors  1150  and  1160  with the stator  1200  may be adapted or configured to receive and operate two propellers, which are made to contra rotate, with the blades adapted to produce thrust in the same direction. The two propellers  1160  and  1170  are shown with the front rotor  1150  shown in  FIG. 1F . 
     Operation of the Invention 
     With reference to  FIG. 1G , the rotor  1100  is shown magnetically suspended in the stator  1200 . The center of rotation  1300  is shown. A vertical axis  1150  is drawn through the center of rotation  1300 . Also shown are radii  1400  drawn from the center of rotation  1300  to points on the stator  1200 . The radii  1400  drawn as illustrated define an angle  1410  (hereafter called  6 ) and the negative of the same angle  1420  or −{acute over (α)}. The angle {acute over (α)} is chosen to be a divisor of 360 degrees. 
     In  FIG. 1H , radii  1414  and  1416  define the angles k{acute over (α)} and −k{acute over (α)} made with respect to the vertical. 
     Now refer to  FIG. 3 . In  FIG. 3  magnetic device pairs ( 3602 ,  3604 ) and ( 3406 ,  3408 ) are fixed on the apparatus. Magnetic devices  3602  and  3406  are permanent magnets and devices  3408  and  3604  are electrically activated and controlled by a control device associated with the apparatus. Devices  3408  and  3604  are fixed to the stator. Devices  3406  and  3602  are fixed to the rotor. Device  3604  is configured to be magnetically energized to be either opposite polarity to or the same polarity as device  3602  the radii  3402  and  3404 . Device  3408  is configured to be magnetically energized to be either opposite polarity to or the same polarity as device  3406 . 
     In  FIG. 3 , the radius  3402  makes an angle X with the vertical  3150 . The radius  3404  makes the angle −X with respect to the vertical  3150 . 
     In  FIG. 3 , if the magnetic devices  3602  and  3604  are energized, the line  3524  drawn between device  3602  and  3604  makes an angle Y with respect to the radius  3402 . 
     When devices  3602  and  3604  are selected, the control logic (illustrated in  FIG. 2 , with the description above) selects devices  3406  and  3608  for energizing. The devices  3406  and  3608  are selected according to the following criteria:
         1. The device  3406  is selected such that the line drawn between  3602  and  3406  is perpendicular to the vertical  3150 .   2. The device  3408  is selected so that if the radius drawn to  3604  is X, the radius drawn to  3408  is −X.   3. The polarity between  3604  and  3602  is minus the polarity between  3408  and  3406 .       

     Selection and Activation of Magnetic Devices on the Stator 
     Magnetic devices on the stator are selected and energized to rotate the rotor. The control mechanism is implemented within a computational framework shown in  FIG. 2 . 
     With reference to  FIG. 2 , the magnetic device selection, activation and control may be implemented (created, compiled, serialized, transmitted, deserialized, stored and executed); for example, within a computing environment  2000 , which includes at least one processing unit  2700  and memory  2730 . In  FIG. 2 , this most basic configuration  2000  is included within a dashed line. The processing unit  2700  executes computer-executable instructions and may be a real or a virtual processor. In a multi-processing system, multiple processing units execute computer-executable instructions to increase processing power. The memory  2730  may be volatile memory (e.g., registers, cache, RAM), non-volatile memory (e.g., ROM, EEPROM, flash memory, etc.), or some combination of the two. The memory  2730  stores executable software—instructions and data  2250 —written and operative to execute and implement the software applications required for an environment supporting practice of the invention. 
     The computing environment may have additional features. For example, the computing environment  2000  includes storage  2740 , one or more input devices  2750 , one or more output devices  2760 , and one or more communication connections or interfaces  2770 . An interconnection mechanism (not shown) such as a bus, controller, or network interconnects the components of the computing environment to communications networks, where the apparatus may be controlled, updated or activated. Typically, operating system software (not shown) provides an operating environment for other software executing in the computing environment, and coordinates activities of the components of the computing environment. 
     The storage  2740  may be removable or non-removable, and includes magnetic disks, CD-ROMs, DVDs, or any other medium which can be used to store information and which can be accessed within the computing environment. For example, the storage may store executable logic and data required to support the processes illustrated in  FIG. 4 . The storage  2740  also stores instructions for the software  2720 , such as software for operating systems and web servers. 
     The input device(s)  2750  may be a touch input device such as a keyboard, mouse, pen, or trackball, a voice input device, a scanning device, or another device that provides input to the computing environment. For audio or video, the input device(s) may be a sound card, video card, TV tuner card, or similar device that accepts audio or video input in analog or digital form. The output device(s)  2760  may be a display, printer, speaker, or another device that provides output from the computing environment. 
     The communication interface  2770  enable the operating system and software applications to exchange messages over a communication medium with sensor devices, and servo-mechanisms in various instantiations of the apparatus of the invention. The communication medium conveys information such as computer-executable instructions, software objects and data in a modulated data signal. A modulated data signal is a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, the communication media include wired or wireless techniques implemented with an electrical, optical, RF, infrared, acoustic, or other carrier. 
     The communications interface  2770  is used to communicate with other devices and computers. For example, the interface  2770  may be attached to a network, such as the Internet, whereby the computing environment  2000  interchanges command, control and feedback signals with other computers, devices, and machinery. 
     DISCLOSURE SUMMARY 
     The present invention has been disclosed in an exemplary embodiment, which may be varied or altered according to specific requirements that are consistent with the inventive scope delineated by the claims that follow.