Abstract:
A magnetic motor system includes a brushless motor with interdigitated permanent magnets longitudinally mounted on a rotor at equal radial positions, and stator windings to drive the rotor in response to pulses from a timer/driver, and stationary recapture windings to recover energy that would otherwise go to waste. One set of batteries is used to drive the motor through the timer/driver, and bridge rectifiers connected to the stationary recapture windings provide electrical current to charge a second set of batteries. The rotor shaft output provides kinetic energy to drive electrical generators, air compressors, etc. A shaft encoder connected to the rotor provides the information needed by the timer/driver to know which stator winding should be pulsed and with what polarity. A power pulse is provided at least every 12.5 degrees of rotation, making the motor self starting.

Description:
COPENDING APPLICATION 
       [0001]    This Application is a continuation-in-part of U.S. patent application Ser. No. 12/344,242, filed by Steven Leonard and Paul Donovan Dec. 25, 2008, and titled, MAGNETIC AIR CAR. Such parent application is incorporated herein in whole by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]    The present invention relates to electrical motors, and more particularly to brushless motors with permanent magnets arranged in the rotor and one set of stator windings to drive the rotor and another set of windings to recover stray magnet energy. 
       DESCRIPTION OF THE PRIOR ART  
       [0003]    The maximum power that can be applied to a brushless direct current motor is very high because no commutator assembly is needed. The electromagnetic forces electrically generated by timed pulses to the stator windings impel the permanent magnets arranged on the rotor. The principal limitation to input power on a brushless motor is the resulting heat that can permanently demagnetize the rotor magnets. 
         [0004]    In motors with brushes and commutators, high amperage inductive electrical currents are switches with the brushes in open air and the switch timing is fixed. As a result, a lot of arcing and wear was unavoidable. Usable voltages are also limited. 
         [0005]    The magnetic fields generated by the stator windings and the permanent magnets spinning on the rotors of brushless motors spill out everywhere and escape doing useful work. The magnetic exchanges between the magnets and the stator windings represents only a portion of the whole. So various devices have been patented to recapture these otherwise wasted magnetic fields. See, U.S. Pat. No. 6,392,370, issued May 21, 2002; U.S. Pat. No. 6,545,444, issued Apr. 8, 2010; U.S. Pat. No. 7,081,727, issued Jul. 25, 2006; and, U.S. Pat. No. 7,109,671, issued Sep. 19, 2006. The motors described by these generally need to be pushed by a smaller starter motor to get them going and they have not been industrialized into practical systems that can be used in practical applications like magnetic generators or the magnetic air car described by the Present Inventors in U.S. patent application Ser. No. 12/344,242, filed Dec. 25, 2008. 
         [0006]    There is a need for a self starting motor that can recapture magnetic energy and convert it back to electrical energy for storage and re-use later. 
       SUMMARY OF THE INVENTION 
       [0007]    Briefly, a magnetic motor system embodiment of the present invention includes a brushless motor with permanent magnets longitudinally mounted on a rotor at equal radial positions and stator windings to drive the rotor in response to pulses from a timer/driver, and a stationary recapture winding to recover energy that would otherwise go to waste. One set of batteries is used to drive the motor through the timer/driver, and a bridge rectifier is connected to the stationary recapture winding provides electrical current to charge a second set of batteries. The rotor shaft output provides kinetic energy to drive electrical generators, air compressors, etc. A shaft encoder connected to the rotor provides the information needed by the timer/driver to know which stator winding should be pulsed and with what polarity. A power pulse is provided at least every 12.5 degrees of rotation, making the motor self starting. 
         [0008]    These and other objects and advantages of the present invention will no doubt become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred SPS receivers which are illustrated in the various drawing figures. 
     
    
     
       IN THE DRAWINGS 
         [0009]      FIG. 1  is a functional block diagram of a system embodiment of the present invention; 
           [0010]      FIGS. 2A and 2B  are end view diagrams of a magnetic motor embodiment of the present invention and show the rotor and stator of a six magnet motor at two slightly different positions; 
           [0011]      FIG. 3  is a perspective view of a six magnet rotor for the motor of  FIGS. 2A and 2B ; 
           [0012]      FIG. 4  is a perspective view of a six magnet stator winding assembly for the motor of  FIGS. 2A and 2B ; 
           [0013]      FIGS. 5A and 5B  are end view diagrams of a magnetic motor embodiment of the present invention and show the rotor and stator of an eighteen magnet motor at two slightly different positions; and 
           [0014]      FIG. 6  is a functional block diagram of a magnetic air car embodiment of the present invention that employs the magnetic motor of  FIGS. 1 ,  2 A,  2 B,  3 ,  4 ,  5 A, and/or  5 B. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0015]      FIG. 1  represents a magnetic motor system embodiment of the present invention, and is referred to herein by the general reference numeral  100 . The magnetic motor system  100  comprises a magnetic motor  102  that is powered by a set of 24-volt batteries  104 . A shaft encoder  106  provides timing information to a timer/driver  108  that sends high current pulses at the right times and polarities to a set of electromagnetic stator windings  110 . A rotor  112  is fitted with many bar-type permanent magnets represented by magnets  114  and  116 . Pulsed magnetic fields from the stator windings  110  push and pull magnets  114  and  116  around an output shaft  118 . In general, there should be a magnet and a matching stator winding disposed no more than 12.5-degrees around the entire 360-degrees of rotation. 
         [0016]    Shaft encoder  106  can be implemented in a number of different ways. The simplest would be a simple cam with breaker points, or a commutator with brushes. A longer lasting and more reliable solution would be to mount small magnets on the shaft  118  and use Hall Effect sensors to detect when the small magnets orbit past. Optical sensors and also be employed that would be capable of reporting the exact angular position of shaft  118 . Timer/driver  108  preferably has pulse width modulation capability for the output pulses it produces, and continuously variable timing advance and delay adjustments to optimize the timing of pulses to the relative angular rotation positions of the magnets  114  and  116  to their corresponding stator windings  110 . 
         [0017]    Timer/driver  108  could be implemented with a relatively modest microcontroller. The shaft encoder information is read periodically, and that reading is translated by a lookup table (LUT) into which stator winding should be switched on and which polarity to use. Simple high power switching transistors can be used for the driver outputs. It may be desirable to make such a look up table programmable, e.g., to vary motor speeds and output torque. 
         [0018]    Output shaft  118 , in turn, can be used to power an air compressor  120  and the compressed air can be used to propel a vehicle with a pneumatic engine. Alternatively, a generator could be attached to produce single-phase 120-VAC residential utility power, or three-phase 480-VAC commercial power. 
         [0019]    A set of stationary recapture windings  122  interwoven with the stator windings  110  recovers electrical energy in the form of an alternating current (AC) that is full-wave rectified by a bridge rectifier  124 . A direct current (DC) is output that can be used to charge another set of 24-volt batteries  126 , and/or operate accessories. 
         [0020]    In alternative embodiments, the charging currents from bridge rectifier  124  can be regulated to prevent overcharging of batteries  126 , and/or to transfer between batteries  104  and  126  with a transfer switch. Various observations seem to indicate there may also be some benefit to battery life and recharging performance if the raw DC pulses and high frequency components are passed straight through to batteries  126  without any limiting or filtering. 
         [0021]    A very strong, non-metallic motor casing  130  is needed for mounting the stator windings  110  and recapture windings  122 , as they each can produce very strong mechanical oscillations and vibrations during operation and loading. Non-metallic materials, like carbon-fiber, and needed to control losses due to eddy currents. The motor casing  130  further must firmly support low friction shaft bushings or bearings, and air bearings  132  are preferred like those described in U.S. patent application Ser. No. 12/344,242, filed Dec. 25, 2008. 
         [0022]      FIGS. 2A-2B  represent one way the magnets on the rotor and stator windings of  FIG. 1  can be configured. This example has been simplified by limiting the number of stator windings and magnets for purposes of this description, double, triple or more are possible in one stage or multiple tandem single-file stages all arranged on the same rotating shaft. 
         [0023]    A motor  200 , seen on end, has a rotor  202  that turns coaxially on a shaft  204  inside a cylindrical stator winding frame  206 . In this example, three groups of stator windings each comprise three bundles of copper windings. A first stator winding group  210  includes individual bundles  211 - 213 , a second stator winding group  214  includes individual winding bundles  215 - 217 , and a third stator winding group  218  includes individual winding bundles  219 - 221 . 
         [0024]    The near-end N and S poles of six bar magnets  222 - 227  in six magnetic stations are seen in  FIGS. 2A-2B . In one prototype, the bar magnets were neodymium HSO and 0.75″ by 0.375″ in cross section. For the clockwise rotation of rotor  202  in  FIG. 2A , all the N-poles of magnets  222 ,  224 , and  226  will be approaching the windings in the second winding group  214 , and all the S-poles of magnets  223 ,  225 , and  227  will be departing the windings in the third winding group  218 . A well-timed pulse of the right polarity to second winding group  214  could pull in all the N-poles of magnets  222 ,  224 , and  226 , while an opposite pulse applied to the third winding group  218  could repulse all the S-poles of magnets  223 ,  225 , and  227 . 
         [0025]    Only 20-degrees of clockwise rotation later,  FIG. 2B  shows that another opportunity to pulse the stator windings now presents itself. This time the first winding group  210  and the second winding group  214  will be activated, but this time in opposite polarity. The shaft encoder  106  ( FIG. 1 ) is used to provide important timing information like this to timer/driver  108 . 
         [0026]    The important properties of permanent magnets in general are:
       remanence (B r ), which measures the strength of the magnetic field;   coercivity (H ci ), the material&#39;s resistance to becoming demagnetized;   energy product (BH max ), the density of magnetic energy; and   Curie temperature (T c ), the temperature at which the material loses its magnetism and therefore the operating temperature limit for motor  200 .       
 
         [0031]    Rare earth magnets have higher remanence, much higher coercivity and energy product, but lower Curie temperatures than other types. The table below compares the magnetic performance of neodymium (Nd 2 Fe 14 B) and samarium-cobalt (SmCo 5 ) rare earth types with other kinds of permanent magnets. 
         [0000]    
       
         
               
               
               
               
               
             
           
               
                   
               
               
                   
                 B r   
                 H ci   
                 (BH) max   
                 T c   
               
               
                 Magnet 
                 (T) 
                 (kA/m) 
                 (kJ/m 3 ) 
                 (° C.) 
               
               
                   
               
             
             
               
                 Nd 2 Fe 14 B (sintered) 
                 1.0-1.4 
                 750-2000 
                 200-440 
                 310-400 
               
               
                 Nd 2 Fe 14 B (bonded) 
                 0.6-0.7 
                 600-1200 
                  60-100 
                 310-400 
               
               
                 SmCo 5  (sintered) 
                 0.8-1.1 
                 600-2000 
                 120-200 
                 720 
               
               
                 Sm(Co,Fe,Cu,Zr) 7  (sintered) 
                  0.9-1.15 
                 450-1300 
                 150-240 
                 800 
               
               
                 Alnico (sintered) 
                 0.6-1.4 
                 275 
                 10-88 
                 700-860 
               
               
                 Sr-ferrite (sintered) 
                 0.2-0.4 
                 100-300  
                 10-40 
                 450 
               
               
                   
               
             
          
         
       
     
         [0032]      FIG. 3  represents a rotor  300  such as could be used in motor  200  ( FIG. 2 ). Six bar magnets  301 - 306  are embedded in the cylindrical surface of a drum body  308 . The bar magnets  301 - 306  are equally distributed, e.g., every 60-degrees, and alternate north (N) and south (S) poles. The rotor  300  turns on a central, coaxial shaft  310  and is balanced to eliminate vibration when spinning. 
         [0033]      FIG. 4  represents a stator winding assembly  400 . A non-metallic frame  402  is made of carbon-fiber in the form of a right cylinder, and such supports the many stator windings that are necessary to electromagnetically work on, e.g., magnets  301 - 306  in rotor  300 . A first stator winding group  410  includes three individual bundles  411 - 413 , a second stator winding group  414  includes three individual winding bundles  415 - 417 , and a third stator winding group  418  includes three individual winding bundles  419 - 421 . 
         [0034]      FIGS. 5A and 5B  a second way the magnets on the rotor and stator windings of  FIG. 1  can be configured. A motor  500 , seen on end, has eighteen bar magnets  501 - 518  on a rotor  519 . Motor  200  in  FIGS. 2A-2B  has only six. In this example, there are four groups of stator windings each comprising three bundles of copper windings. Motor  200  in  FIGS. 2A-2B  has only four. 
         [0035]    A first stator winding group  520  includes individual bundles  521 - 523 , a second stator winding group  524  includes individual winding bundles  525 - 527 , a third stator winding group  528  includes individual winding bundles  529 - 531 , and a fourth stator winding group  532  includes three individual winding bundles  533 - 535 . Rotor  519  turns coaxially on a stainless steel shaft  536  inside a cylindrical stator winding frame  538  made of carbon-fiber materials. Epoxy encapsulents can be used to secure the winding bundles to the stator winding frame  538 . 
         [0036]    Assuming clockwise rotation of rotor  530  in  FIG. 5A , all the N-poles of magnets  501 ,  507 , and  513  will be approaching the windings in the fourth winding group  532 , and all the S-poles of magnets  502 ,  508 , and  514  will be departing. A well-timed pulse of the right polarity to fourth winding group  532  could pull in all the N-poles of the magnets  501 ,  507 , and  513  and simultaneously repulse all the S-poles of magnets  502 ,  508 , and  514 . The other three winding groups  524 ,  528 , and  532 , will have similar opportunities as the rotor continues to turn clockwise. There are so many magnets and windings in this example that motor  500  can be self-starting and not have any dead spots that would necessitate a starter motor. The shaft encoder  106  used would therefore have to provide valid angular position information even when rotor  530  is stalled. 
         [0037]    For example,  FIG. 5B  shows rotor  530  has advanced a little clockwise over the position shown in  FIG. 5A . All the N-poles of magnets  505 ,  511 , and  517  will be approaching the windings in the first winding group  520 , and all the S-poles of magnets  506 ,  512 , and  518  will be departing. A well-timed pulse of the right polarity to first winding group  520  could pull in all the N-poles of the magnets  505 ,  511 , and  517  and repulse all the S-poles of magnets  506 ,  512 , and  518 . The next two winding groups  524  and  528  will have similar opportunities as the rotor continues to turn clockwise. 
         [0038]    Timer/driver  108  ( FIG. 1 ) could, for example, be configured to provide high energy pulses of the appropriate polarities and durations to winding groups  520 ,  524 ,  528 , and  532  of motor  500 . Particular applications may use one or more “flying capacitors” that are charged slowly between the delivered pulses, and when switched to the corresponding stator winding group have very low source impedances and can deliver very sharp pulses. 
         [0039]      FIG. 6  represents a magnetic air car embodiment of the present invention, and is referred to herein by the general reference numeral  600 . The magnetic air car  600  includes a storage battery  602  to operate a magnetic motor  604 . Such magnetic motor has been described and illustrated in  FIGS. 1 ,  2 A,  2 B,  3 ,  4 ,  5 A, and  5 B. The magnetic motor  604  drives a star-rotor compressor  606 . The star-rotor type compressors have rotors which are synchronized not to touch one another during operation. 
         [0040]    In one embodiment of the present invention, battery  602  includes a sodium free complex silicon salt electrolyte as described in PCT published patent application WO 01/13454 A1, published Feb. 22, 2001. Greensaver Technology Corporation (Ningbo, China) says they hold a patent for their so-called GREENSAVER BATTERY. Silicone Batteries USA imports these batteries to the US. See,www.siliconebatteriesusa.com/. The silicone battery is marketed as not having most of the bad qualities of lead acid batteries, e.g., high internal resistance, poor cold temperature performance, and significant self discharging rates. Silicone batteries are said to be able to present more than 80% of their total capacity even at temperatures as low as +15° F. 
         [0041]    Filtered, ambient air or recycled pressurized air is pumped up to about 200-PSI by star-rotor compressor  606  to produce a high-pressure (HP) supply  608 . A pair of tanks  610  and  612  are used to store pressurized air for release as HP supply  614  into a series of step-up compressors. 
         [0042]    A first coupled pair of these are compressors  620  and  622  which have a common shaft  624  floated on an air bearing  626 . This combination may be referred to herein as primary turbo TWIN 1 . Similarly, a second pair of compressors  630  and  632  have a common shaft  634  floated on an air bearing  636 . This combination may be referred to herein as primary turbo TWIN 2 . HP supply  614  drives a pelton-type impulse turbine side of each compressor  620 ,  622 ,  630 , and  636 , and the exhaust is released to atmosphere. A pressure multiplication is provided like in a turbofan jet engine on the driven side of each compressor  620 ,  622 ,  630 , and  636 . This produces a very high-pressure (VHP) supply  638  from HP supply  608 . 
         [0043]    A large coupled pair of compressors  640  and  642  have a common rotating shaft  644  on an air bearing  646 . This combination may be referred to herein as a secondary turbo BOOST. Compressors  640  and  642  are driven by HP supply  614 . Compressor uses this to step up VHP supply  638  into an ultra high-pressure (UHP) supply  648 . The driven sides of compressors  620  and  632  then step this up to a super high-pressure (SHP) supply  650  and  652 . Both are applied to a laminar jet  654  to produce a laminar airflow  656  into the driven side of compressor  642 . 
         [0044]    The final result of all the pressure step-ups through compressors  620 ,  622 ,  630 ,  632 ,  640 , and  642 , is extra high-pressure (EHP) supply  660 . This is applied to a pneumatic torque converter  662 , the hydraulic equivalent of which is a standard automatic transmission torque converter used in automobiles. For example, this includes a pelton-type impulse turbine. 
         [0045]    Pneumatic torque converter  662  couples with a driveshaft to a transmission and differential  664 . The output torque is then used to drive axles to wheels  666  and  668  of a car. Power throttling is provided by modulating HP supply  608  from the star-rotor compressor  606 . 
         [0046]    Exhaust  669  from pneumatic torque converter  662  is ducted to a compressor pair  670  and  672 . A shaft  674  on an air-bearing  676  couples these together. This combination may be referred to herein as exhaust turbo recovery. Ambient air drawn in by a filter  678 , and recycle air from compressor  672 , are input to compressor  670 . They receive a boost that is applied to the input HP supply  614  through a priority valve  679  to boost acceleration while the car is under way. All ambient air exchange takes place through air filter  678 . 
         [0047]    The compressor pair  670  and  672 , as do the others, provides a multiplication in the compressive pressures in gases that pass through the vanes of the driven sides. The multiplication is on the order of five to seven times. 
         [0048]    An independent air bearing supply system includes an electric compressor  680 , a dedicated air storage tank  682 , and an air bearing supply pressure  684 . A control system included with magnetic air car  600  must float all the air bearings  626 ,  636 ,  646 , and  676  first, before allowing any supply pressure  608  or  614  to spool up any of the compressors. Any loss of air bearing supply pressure  684  must be immediately used to shut down supply pressure  608  and  614  to stop the compressors spinning. Air bearings could also be usefully employed in magnetic motor  604 , star-rotor compressor  606 , and torque converter  662 . The electric compressor  680  could be powered by battery  602 . 
         [0049]    Accessories, other than electrically powered ones like power steering and power windows, can be provided with a mechanical power take off (PTO) from magnetic motor  604  or pneumatic torque converter  662 . A small pneumatic motor could also be used to drive accessories like air conditioning, alternators, and generators from taps on the HP supply  608  or discharge from compressor  672 . 
         [0050]    The compressors are put in pairs around respective air bearings  626 ,  636 ,  646 , and  676  to balance the lateral forces applied to the vane ends of shafts  624 ,  634 ,  644 , and  674 . A proper balance eliminates Milankovitch-like wobbles, e.g., changes in the axial tilt, axial precession, and eccentricities of the turbo-shafts  624 ,  634 ,  646 , and  676  over periods of time. 
         [0051]    A particular type of oil-free air bearing used in connection with a turbocharger is reported by Minoru Ishimo, “Air Bearing for Automotive Turbocharger”, in R&amp;D Review of Toyota CDRL, Vol. 41, No. 3, (c) 2006, Toyota Central R&amp;D Labs, Inc. Some of the details in the article may be useful in implementing compressors  620 ,  622 ,  630 ,  632 ,  640 ,  642 ,  670 , and  672 . 
         [0052]    In general, a magnetic air car uses a magnetic motor to compress input air and save moderately compressed high-pressure (HP) air in storage tanks. The compressor and storage tanks deliver the high-pressure working air and operational flows to several stages of compressors that boost the pressures during driving to very high-pressure (VHP), then ultra high-pressure (UHP), then super high-pressure (SHP), and finally to extremely high-pressure (EHP). A pneumatic torque converter uses jets of the EHP to turn an input shaft of a transmission and differential. These, in turn, drive the powered wheels of a car. The compressors float a connecting shaft with matching vanes and impellers on opposite ends on air bearings to reduce shaft turning friction to near zero. The balance of forces between the two ends of a coupled turbo pair allows a simple air bearing design to operate safely and reliably at high rotational speeds. 
         [0053]    Star-rotor compressor  606  can be like the fifth generation products marketed by StarRotor Corporation, Bryan, Tex. (See, starrotor.com). The Company reports that their compressor can process any vapor or gas with the only associated design consideration being the selection of materials compatible with the gases being compressed. The compressor works by using inner and outer star rotors, with seven and eight points respectively, that rotate on corresponding axes. A drive mechanism synchronizes the rotors so they do not bear on one another. Seals made with sacrificial coatings are used between the rotors and stationary porting components. 
         [0054]    As the rotors turn, a chamber enlarges, reaches a maximum volume, and then squeezes closed. Inlet gas enters through the intake port as the void opens. Once the gas is captured, the chamber volume is squeezed causing the pressure to increase. After a design pressure is reached, the gas pushes out through a discharge port. The chamber ports open eight times per rotation of an outer rotor, allowing the compressor to process large volumes of gas. The position of the leading edge of the discharge port determines the compression ratio. If the leading edge is positioned to make the discharge port large, the compression ratio will be small. If the leading edge is positioned to make the discharge port small, the compression ratio will be high. By using a sliding mechanism, the leading edge position can be changed on the fly, giving the compressor a variable compression ratio. A magnetic motor could be integrated within to drive the compressor. 
         [0055]    In operation, an electric motor driving auxiliary compressor  680  immediately begins filling the air bearing tank  682  when an ignition key is turned to the run position. The air bearing tank  682  supplies the pressurized air needed to suspend the air bearing loads of each component, e.g., 40-PSI@3.8 cubic feet per minute (cfm). Pressure sensors detect when a predetermined minimum operating pressure is present, and the magnetic motor  604  and star-rotor compressor  606  are allowed to start-up. Auxiliary compressor  680  is cycled on-off by pressure controller switches to keep a constant supply of compressed air in the air bearing tank  682 . 
         [0056]    When the car is not in use, the air bearings do not need to remain suspended. A timer is used to allow the air bearing equipped components to spin down. After enough inertia has been spent and the possibility of damage to the air bearings has been reduced to zero, the timer shuts-off air flow from the air bearing tank  680 , and the car and all its engine components are stopped. 
         [0057]    Although the present invention has been described in terms of the presently preferred embodiments, it is to be understood that the disclosure is not to be interpreted as limiting. Various alterations and modifications will no doubt become apparent to those skilled in the art after having read the above disclosure. Accordingly, it is intended that the appended claims be interpreted as covering all alterations and modifications as fall within the “true” spirit and scope of the invention.