Abstract:
An electric motor utilizing a plurality of linearly reciprocating magnetic elements comparable to pistons in a fluid motor and a linear-to-rotary motion translation element comprising a sinusoidal member engaging the reciprocating magnetic elements. The sinusoidal member is fixed to a rotary output shaft. Each reciprocating magnetic element has rollers for miminizing friction while engaging the sinusoidal cam and additional rollers for guiding reciprocation within the housing of the motor. In a preferred embodiment, the electric motor is a DC motor which drives an AC generator.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application 60/903,296, filed Feb. 26, 2007, entitled Magnetic Power Supply Engine, which is incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to electric motors and rotary appliances driven by electric motors. 
       DESCRIPTION OF THE PRIOR ART 
       [0003]    Electric motors are well known. An electric motor is essentially a rotary arrangement of magnets arranged so that application of electrical power induces reactive magnetic fields which act by attraction or repulsion or both to generate torque in an output shaft. Most electric motors are arranged to have field coils act directly on a rotatable member or rotor. 
         [0004]    The prior art is replete with heat or fluid pressure driven piston devices which utilize sinusoidal cams, tracks, grooves, or the like to translate linear piston motion to rotary output motion. A few electrical devices have been proposed, which electrical devices utilize sinusoidal-to-rotary motion translation. However, motors employing plural linearly moving magnetically driven elements which engage a sinusoidal cam at opposing sides of the latter are not known in the prior art. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention in at least one embodiment provides an electric motor utilizing a plurality of linearly driven solenoid elements, which will be referred to hereinafter as magnetic pistons. The electric motor has a sinusoidal cam which interacts with the magnetic pistons to produce a rotary output. The rotary output drives a rotary appliance, which in one embodiment is a generator. An advantage of this arrangement is to utilize direct current from a storage battery to drive an alternating current generator, or alternator, when a usual AC power source fails. 
         [0006]    The magnetic pistons transfer motion to a sinusoidal cam having at least relatively two high points therealong and a corresponding number of low points therealong. This characteristic enables the pistons to go through more stroke cycles than one per revolution of the output shaft of the motor. Consequently, greater power is developed at relatively low output shaft speeds than would be the case in motors in which a magnetic piston or its equivalent goes through one stroke cycle for each revolution of the output shaft. A stroke cycle signifies that a magnetic piston, starting at any arbitrary point along its reciprocating path, moves to the extreme point of travel in one direction, then to the extreme point of travel in an opposed direction, and returns to the initial starting point. 
         [0007]    It is, therefore, an object of the invention to provide an electric motor which uses a plurality of magnetic pistons. 
         [0008]    It is an object to increase power of an electric motor having magnetic pistons over that which would result from a one-to-one correspondence between piston stroke cycles and output shaft revolutions. 
         [0009]    It is a further object to use magnetically activated pistons to drive a sinusoidal cam that drives an output shaft. 
         [0010]    It is an object of the invention to provide improved elements and arrangements thereof by apparatus for the purposes described which is inexpensive, dependable, and fully effective in accomplishing its intended purposes. 
         [0011]    These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0012]    Various objects, features, and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein: 
           [0013]      FIG. 1  is a diagrammatic side elevational view of major internal parts of an electric motor according to one embodiment of the invention. 
           [0014]      FIG. 2  is a perspective detail view of an embodiment of one magnetic piston, and is drawn to scale reduced from that of  FIG. 1 . 
           [0015]      FIG. 3  is a perspective view of part of an electric motor according to an embodiment of the invention, shown connected to a motor driven appliance. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0016]      FIG. 1  of the drawings shows certain significant internal operative components of a novel electric motor  1  according to one embodiment of the present invention. An output shaft  10  having an axis of rotation A is fixed to a plate  12  by an intervening enlargement  14 . These components may be fully integral with one another, or may be separate components joined in fixed relationship to the others. Plate  12  acts as a sinusoidal cam for reasons to be explained hereinafter, having a sinusoidally configured first surface  16  and a parallel, opposed sinusoidally configured second surface  18 . 
         [0017]    Output shaft  10  is supported on suitable bearings  20  within a housing  22 . In  FIG. 1 , housing  22  is shown only representatively. In practice, housing  22  may take a generally cylindrical configuration, such as housing  122  of  FIG. 3 , or may have any other desired configuration including openings (not shown) to promote convective cooling where desired. Bearings  20  are shown representatively, and will be understood to provide both radial constraints on travel of output shaft  10  and also axial constraints or thrust control, as desired. Bearings  20  may be supported by any suitable structure such as races and the like (not shown) formed as part of housing  22 . As these functions and structures are well known within the field of electric motors, further details regarding the same are omitted herefrom. It will be seen that output shaft  10  projects outwardly from housing  22  at its distal end  24 . Preferably, distal end  24  includes a keying groove, a flange, or any other known structure (none shown) to facilitate connecting output shaft  10  to an appliance to be driven by motor  1 . 
         [0018]    Motor  1  includes a plurality of magnetically moved pistons  26 ,  28  which are disposed to reciprocate along linear paths located within housing  22 . As depicted in  FIG. 1 , each magnetic piston  26  or  28  can move vertically (as indicated by arrows B and C) within limits. Magnetic piston  26  is shown near the upper limit of its travel within motor  1 , and magnetic piston  28  is shown near the lower limit of its travel within motor  1 . As is well known to those skilled in the art, the relative position of each piston will depend on the number of pistons distributed about the cam and the number of peaks and valleys in the cam. Here, as shown in the  FIG. 3 , there are three pistons shown surrounding a sinusoidal cam plate  12  having two peaks. Greater or fewer numbers of pistons and peaks can be used, with a six piston or twelve piston configuration being preferred with a cam having two peaks. 
         [0019]    Each piston  26  or  28  can move to between a top dead center and a bottom dead center to cover a distance defined by the highest peak and lowest valley of the sinusoidal cam. In this way, the cam defines the linear path for each piston  26  or  28 . 
         [0020]    Each piston has an upper bearing and a lower bearing. By way of example, piston  26  has an upper bearing  30  and a lower bearing  32  and piston  28  has bearings  40 ,  41 . Preferably the bearing are low friction non-ferrite materials such as felt, polyurethane, NEOPRENE or TEFLON™ or similar material that will not interfere with the magnetic piston. Similarly, other bearings shown (e.g.,  56 ,  58 ,  60 ,  62 ) can be made of non-metals to provide low-friction retention and spacing of the parts without interfering with the magnetic portions of the motor. The piston may be magnetic or ferrous, or may be made of aluminum or other non-magnetic material and incorporate magnets, ferrous materials or magnetic materials at its top and/or bottom portions. 
         [0021]    As employed herein, orientational terms such as “up”, “upper”, “down”, “lower”, “vertical”, “horizontal”, etc., refer to directions as seen in the depictions of the various drawing figures which are referenced in textual description. Obviously, these orientations change with the position of a motor (e.g., motor  1 ) within its environment. Therefore, it will be understood that these orientational terms are introduced for semantic convenience, and should not be taken as literal conditions for practicing the invention. 
         [0022]    Plate  12  has an upper sinusoidal surface  16  and a lower sinusoidal surface  18 . When plate  12  is assembled to piston  26  as seen in  FIG. 1 , plate  12  partially occupies a recess  34  formed in piston  26 . Upper bearing  30 , which is mounted to an upper wall  36  partially defining recess  34 , engages upper sinusoidal surface  16  of plate  12 . Lower bearing  32 , which is mounted to a lower wall  38  partially defining recess  34 , engages lower sinusoidal surface  18  of plate  12 . It will be appreciated that vertical movement of piston  26  induces rotation of plate  12  as pressure of linear motion of piston  26  is transferred to plate  12 , and ultimately to output shaft  10 , by bearings  30  and  32 . Piston  28  and the its associated bearings  40  and  41 , as with other pistons (not shown), if provided, essentially repeat structural and functional characteristics of piston  26 , and need not be further described hereinafter. 
         [0023]    Plate  12  serves as a linear-to-rotary motion translation apparatus, given its relationship to magnetic pistons  26  and  28 , which are arranged to bear against plate  12  when moving along their linear paths. As configured, plate  12  causes pistons  26 ,  28  to undergo two stroke cycles each for each revolution of output shaft  10 . This is because sinusoidal surfaces  16 ,  18  of plate  12  of  FIG. 1  each define a first high point  43  (“peak”) and a second high point  45 . High points  43 ,  45  are separated by intervening low points (“valleys”) including low point  47  and a second low point not visible in  FIG. 1 , but located diametrically across plate  12 . 
         [0024]    Pistons  26  and  28  reciprocate along their respective paths responsive to magnetic fields. These magnetic fields are induced by stationary magnetic field inducing elements supported within housing  22 . These field inducing elements may be coiled electrical conductors or coils  42 ,  44 ,  46 , and  48 . Coils and ferromagnetic cores, where desired, are well known and need not be set forth in greater detail. Pistons  26 ,  28  may be fabricated from a ferromagnetically responsive material such as iron or steel, may have incorporated therein a ferromagnetically responsive component, or may have a magnet integrated therein. Magnets may be ferrous or non-ferrous, such as aluminum nickel cobalt alloys. Coils  42 ,  44 ,  46 ,  48  are supplied with electrical power by any suitable source of electrical power and switching apparatus, the power and switching apparatus being shown representatively as  49  in  FIG. 1 , which may include an electrical control module for controlling the timing and switching. The power source and switching apparatus may be integral, as literally depicted in  FIG. 1 , or may be separate. For example, the switching apparatus may comprise contacts and limit switches (neither shown) located within housing  22 , while the power source may comprise a remote battery (not separately shown) and a circuit  51  connecting the power source to coils  42 ,  44 ,  46 ,  48 . Field control circuits and switching apparatus are well known in the electrical arts, and any suitable circuitry and switching apparatus known in the prior art may be incorporated into motor  1  and its supporting apparatus. Of course, although depicted by a single line in  FIG. 1 , circuitry will be understood to include conductors which are sufficient in number and arrangement to satisfy operative requirements of the functions they are described as providing. 
         [0025]    Turning now to  FIG. 2 , further structural features of piston  26  are set forth. Piston  26  has an external surface  54 . A plurality of guide rollers  56 ,  58 ,  60 ,  62  are disposed at external surface  54 . Guide rollers  56 ,  58 ,  60 ,  62  serve to guide piston  26  as it moves in its linear path by engaging a guide surface formed in housing  22  by rolling contact therewith. The guide rollers may be non-rotating, low friction spacers made of felt, TEFLON™, or other non-ferrous materials. 
         [0026]    As seen in  FIG. 3 , housing  122  of motor  101 , which is generally similar in operating principles to motor  1 , has three cylindrical openings  64 ,  66 ,  68 . Each opening  64 ,  66  or  68  houses one piston, preferably of the type shown in  FIG. 2 . In the embodiment of  FIG. 3 , the cylindrical surfaces of cylindrical openings  64 ,  66 ,  68  serve as guide surfaces which constrain their associated pistons to move only linearly, parallel to axis A of rotation of output shaft  110 . The pistons associated with housing  122  are preferably similar to piston  26  of  FIG. 2 . Rollers of the pistons contact the cylindrical surfaces of cylindrical openings  64 ,  66 ,  68 . The housing is preferably made from aluminum to minimally interfere with magnetic fields. The length of the openings should be sufficient to allow the pistons to complete their entire linear travel without striking a wall or endplate. Preferably a space of 0.040 inches of spacing is provided between the walls and the piston at its top most and bottom most position. Preferably, the cylinder is appropriately vented to facilitate movement of the piston without pressure buildup within the cylinder during travel of the piston. A space may be provide between the sidewalls of the piston and the housing of preferably ⅛ inch to facilitate air flow past the cylinder as it travels, with guides (e.g. . . . ,  56 ,  58 ,  60 ,  62 ) maintaining proper orientation of the piston within the housing. Since there is no combustion in the motor, piston rings and the like are not required. 
         [0027]    Guide surfaces, which define the linear paths of their associated pistons, may take forms other than cylindrical. For example, grooves or tracks (neither shown) may be provided to guidingly receive the rollers of the pistons. The cross sectional configuration of openings corresponding in the function of receiving magnetic pistons, and also of magnetic pistons, may be other than circular. 
         [0028]      FIG. 3  shows a further feature of motor  101 . Output shaft  110 , which is generally similar to output shaft  10  of  FIG. 1 , is connected to a rotatably driven appliance. Motor  101  is a DC motor with its stationary magnetic field inducing elements electrically connected to a battery or other suitable source of direct current. The driven appliance may be an alternating current generator  170 , which converts the rotary motion of the shaft into alternating current electricity. However, connection of an AC generator to the output shaft of the DC motor is not necessary to practice the invention. This arrangement enables, for example, AC power to be provided to occupied premises (not shown) where utility electrical power has failed, and where a storage battery is the only power source available, so that operation of AC electrical devices is enabled despite loss of utility AC power. Standby batteries are well known measures for accommodating transient power failures, and their construction and connection need not be detailed further. 
         [0029]    The present invention is susceptible to modifications and variations from the embodiments which have been shown and described. For example, the novel motor may be arranged to be AC operated. The number of pistons and of high and low points of the sinusoidally configured plate may be varied to suit. 
         [0030]    Rollers and roller bearings may be replaced by non-rotatable bearing devices, or preferably non-metallic, no-rotatable bearings such as felt or TEFLON™. 
         [0031]    A motor output shaft such as output shafts  10  and  110  may be arranged to project from both sides of their respective motors  1 ,  101 , if desired. The output shaft may be used to provide motive force to drive, for example, wheels of an automobile to convert DC power to rotary motion for instance in an electric car or a vehicle having an energy recovery systems (“hybrid vehicle”). 
         [0032]    The output shaft could also be used to generate DC power to trickle charge the power source. If the motor is operated in constant motion, it may be desirable to convert any energy that would otherwise be wasted into a charge sent back to the battery. Additionally, since most generators and alternators can be reversed to convert one to the other, the motor could be used as a generator to charge a battery instead of as a motor run from a battery. 
         [0033]    It will also be appreciated that surfaces  16 ,  18  of plate  12  need not be purely sinusoidal. For example, surfaces  16 ,  18  may include a straight portion intervening between transitional curved portions. 
         [0034]    As best seen with reference to  FIGS. 4-9 , further embodiments of the invention are shown.  FIG. 4  shows an electric motor  200 . The motor has a central shaft  210  connected affixedly to a cam  212 . This cam may be sinusoidal or similar pattern having peaks and valleys. A number of pistons  214  are located proximate the cam  212 . Preferably an even number of pistons are distributed evenly about the cam. In  FIG. 4 , six pistons are shown, but any number can be provided depending on the power output and force distribution desired. Since each piston moves independently of each other, the only theoretical limitation on the number is the amount of space provided around the cam to physically place the pistons in contact with the cam. However, consideration must also be made that at each position, a motivating magnet must be properly aligned with the piston, and therefore the actual number of pistons that can surround the cam is much smaller as magnets that were too close together would interfere with each other or with magnets on the other pistons as discussed below. 
         [0035]    Each cam as shown in  FIGS. 7 and 8  has a number of rollers or followers  216  configured on either side of the cam to ride along the profile of the cam  212 . As the cam rotates and a peak is presented to the piston, the pistons will rise. Or conversely, as the piston rises, the cam will rotate to a position where the profile of the cam matches the height of the piston rollers. In this way, the cam can drive the pistons or the pistons can drive the cam. In this way, rotary motion can be converted to reciprocal motion or vice versa. One skilled in the art would appreciate that other follower mechanisms could be used to match the motion of the piston and cam, with the rollers providing a simple way of allowing the cam to move past the piston with the minimum amount of friction. However, the cam or a portion extending from the cam could ride in a slot in the piston or the piston could have an arm that was designed to ride in a slot, groove of the cam to allow the cam and piston to move as a function of the movement of the other. 
         [0036]    The main shaft  210  is secured into two opposing housings  220 . A bearing (not shown) may be provided in the housing to allow to locate the shaft within the housing while allowing the shaft to rotate with minimum friction. However, depending on the speed on the shaft and the housing material, bearings may not be required in all applications. 
         [0037]    The housings also secure opposite ends of the pistons in mating holes  218  through the housing. Unlike the pistons, however, the piston shafts preferably do not extend all the way through the housings to the area beyond the housing, but are limited to travel within the housing. The thickness of the housing may be selected based on the total travel of the pistons, which is related to the amplitude of travel of the cam. If the housing is thicker than the cam amplitude, then the ends of the pistons can travel within the housing without accidentally releasing therefrom. However, as discussed below, the ends of the piston may extend beyond the walls of the housing. 
         [0038]    The pistons are shown as having a substantially cylindrical body  222  where the rollers  216  are connected. However, the shape is not critical to the operation of the invention, but is preferred for strength and ease of manufacture. A cut out portion  224  is also shown to on the body to accommodate all or a portion of the rollers and to locate the cam plate closer to the central axis of the piston. Either end of the piston may include a reduced section to lighten the piston while still maintaining the structural integrity. As shown in  FIGS. 8 and 9 , the ends of the piston may include a square neck section  226  connecting the out ends with the central body  222 . The ends of the piston  228  that ride within the housing are preferably cylindrical to be easily maintained within a matching shape opening in the housing. However, other shapes can be used so long as the housing and the piston ends have complementary shapes. As shown in  FIG. 9 , the piston ends may include a number of grooves  230  for containing ball bearings  232  for nonfrictionally maintaining the pistons aligned in the holes in the housing. A number of bearing slots are 
         [0039]    The very ends of the piston shaft include magnets  234  ( FIG. 9 ). Preferably the magnets are unipolar, permanent magnets having one magnetic pole on each side of the magnet. The magnets on the pistons preferably include a “North” pole facing outwardly. Each end of the shaft includes a faceplate ( 230 ). The faceplate on the right of  FIG. 4  has been removed to show the details of the housing  220 .  FIG. 5  shows the detail of a faceplate (“endplate”) according to the invention. 
         [0040]    A number of slots  232  on the endplates are available to receive magnets. One magnet  234  is provided for each peak on the cam, and one for each valley on the cam. Preferably there is one piston for each peak and each valley as well so that there are no gaps in driving the pistons as the endplate rotates. The end plate must be aligned properly with the cam such that the magnets in the end plate appropriately force the pistons in the proper direction on the cam. In this embodiment, six magnets  234  and six piston  214  are provided, though the ratio could be changed. These magnets are preferably permanent magnets, but electromagnets may be substituted as described below. The magnets are located on the end plate such that as the magnet begins to approach a piston, a magnet in the end plate closest to the piston will contain a magnet having the same polarity as the near end of the piston. The opposite end of this same piston will have a polarity that is the opposite the polarity of the magnet in line with the piston in the opposite end plate. In this way, when at any one time a piston is being motivated against a near end and drawn towards the far end. This provides significant motivational force to move the piston axially away from one endplate towards the other. As the piston travels, the roller followers  216  move against the cam causing the cam to rotate out of the way of the piston, thereby converting reciprocal motion to rotary motion. As the cam rotates, the shaft connected affixedly to both endplates and the cam causes the endplates to rotate to move the magnets out of alignment with the piston. After the piston has reached its full travel away from the endplate towards the other end plate, since the endplate has alternating polarity magnets, the endplate will have rotated enough to bring opposite polarity magnets in near alignment with the piston. Now the piston will be urged in the opposite direction to return towards the original position under the reversed polarity of the aligning magnets. The endplate now furthest from the piston will have the same polarity as the adjacent piston end drawing the piston back towards the end plate will the opposite endplate and opposite piston end will have a same polarity to drive the piston away from the endplate closest to the piston end. In this way three piston are being driven towards one endplate while three pistons are being driven towards the opposite end plate. 
         [0041]    In a further embodiment, the device could be made using electromagnets instead of permanent magnets. In this case, it would not be necessary to have the endplates rotate, as current could be used to reverse the polarities of the magnets in the fixed endplates to motivate the pistons at the proper time. A time mechanism which is synchronized with the cam or cam shaft  210  could be used to time the polarity changes of the magnets. Alternately, the travel of the pistons could be used to affect switching of the magnets, however this may be more complicated to prevent the switching of magnets from being out of synch with each other. A 12 volt battery, for example, could be used to power the electromagnets by converting the DC power to AC to power the magnets with the proper alternating current. 
         [0042]    One effect of the output shaft and input shaft being coupled is that the device will be self building, as the magnets motivate the cam to move faster, the cam will motivate the magnets to move faster. This will build to a speed determined by the power of the magnets and the amount of drag on the device. While the output shaft and/or the input shaft could be connected to any device, it is envisioned that a generator could be connected to the device to generate electricity. One skilled in the art would appreciate that one protruding shaft could be remove resulting in only a singular shaft used for output, depending on the space requirements or other requirements of the motor. 
         [0043]    Other embodiments and variations can also be used, and each element of object of the invention need not be in each embodiment. The invention is not to be limited by the description of the specific embodiments above, but only by the accompanying claims.