Abstract:
A device for providing rotational torque includes a stator with a permanent magnet rotatably mounted contained within, a rotor arranged on one side of the stator, a pair of permanent magnets rotatably mounted on oppositely spacing sides of the rotor, which stator and rotors are arranged with gaps left therebetween in an axial direction of the driveshaft, the rotor being mounted to the driveshaft. For further acceleration of the rotor, there are mounted several permanent magnets in the stator housing, arranged in a circumferential arrangement relative to the rotor. These acceleration magnets are arranged such that the size increases with each acceleration magnet approaching the stator magnet.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention is, in general, in the field of devices for providing rotational torque, and, in particular, in the field of permanent magnet motors. 
       BACKGROUND OF THE INVENTION 
       [0002]    In known permanent magnet motors, the attractive forces of the stator magnets will cause the rotor to turn until the highest degree of attraction is obtained. However, this arrangement runs into a problem when trying to rotate past the last set of stator magnets which are closest to the poles of the rotor magnet. The effect known as cogging will tend to cause the rotor magnet to hold onto the stator magnet with the highest amount of attraction, thereby causing the rotor to stall. Electro-magnets are employed in the vast majority of permanent magnet motors to keep the rotor moving past the stator magnets. Electro-magnets, however require an external power source, which has been a seemingly inescapable feature of the common permanent magnet motor. 
       SUMMARY OF THE INVENTION 
       [0003]    In view of the above described problem, an object of the present invention is to provide a means for reducing the separation forces in a permanent magnetic gate thereby reducing the energy loss. 
         [0004]    An aspect of the present invention involves a permanent magnet device causing motion of a rotor relative to a stator. The permanent magnet device includes a magnetic gate that allows continued motion of the device without an external power source. 
         [0005]    Another aspect of the present invention involves a device for providing rotational torque in the form of an axial motor comprising a stator with a permanent magnet rotatably mounted contained within, a rotor arranged on one side of the stator, a pair of permanent magnets rotatably mounted on oppositely spacing sides of the rotor, which stator and rotors are arranged with gaps left therebetween in an axial direction of the driveshaft, the rotor being mounted to the driveshaft. For further acceleration of the rotor, there are mounted several permanent magnets in the stator housing, arranged in a circumferential arrangement relative to the rotor. These acceleration magnets are arranged having increasing magnetic flux density, size with each acceleration magnet approaching the main stator magnet. 
         [0006]    The rotor magnets include a means for independent rotation within the rotor timed for a specific movement therein relative to the stator magnet, allowing a parallel position to be held as the rotor magnet passes the main stator magnet. 
         [0007]    The stator gate magnet includes a means for rotation timed with the circumferential location of the rotor magnets allowing a parallel position to be held relative to the passing rotor magnet. 
         [0008]    The main stator and rotor magnets are rotated so as to have their pole faces pointed towards each other only as they are approaching. 
         [0009]    The length of the main stator and rotor magnets are held in a specific proportion, the length of the main stator magnet being held to be longer than the rotor magnet. Further, the non working end of the main stator magnet is curved away from the rotor magnet. 
         [0010]    The attractive pole faces of the main stator and rotor magnets are held with a convex surface (preferably a full radius). 
         [0011]    With the constitution described above, since the magnetic field of a permanent magnet diminishes as it moves away from the pole face along the side face of the magnet, there exists a preferred means of separating two permanent magnets when arranged in a parallel configuration and when the main stator magnet is longer than the rotor magnet. As the rotor magnet moves away from the pole of the main stator magnet, it encounters a diminishing magnetic field. At this point the two magnets may be separated with less force than the maximum attractive force of either the main stator or rotor magnet. Therefore when the rotor magnet is moved past the main stator magnet, not all of the energy gained during the attractive phase of rotation is lost. 
         [0012]    Preferably, the materials used to hold the rotor and stator magnets are non magnetic, since the as designed magnetic field arrangement is critical to the operation of the device. 
         [0013]    The accelerator magnets form an attractive magnetic field of increasing strength as the rotor magnet approaches the main stator magnet, providing additional rotational energy to the rotor. 
         [0014]    One or more implementations of the aspect of the invention described immediately above includes one or more of the following. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  is a side view of an embodiment of a permanent magnet motor; 
           [0016]      FIG. 2  is a cross sectional view of the permanent magnet motor of  FIG. 1 ; 
           [0017]      FIG. 3  is a cross sectional view of the permanent magnet motor of  FIG. 1 ; 
           [0018]      FIG. 4  is a front view of the permanent magnet motor of  FIG. 1 ; and 
           [0019]      FIG. 5  is a cross sectional view of the permanent magnet motor of  FIG. 4 . 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0020]    With reference to  FIGS. 1-5 , an embodiment of a permanent magnet motor  10  and method of use that provide a magnetic gate that allows continued motion of a rotor relative to a stator without an external power source and with low cogging will be described. Although a permanent magnet motor is shown and described herein as an exemplary device for providing rotational torque, in alternative embodiments, the aspects of the present invention shown and described herein are applied to other types of devices for providing rotational torque. Permanent magnet motor  10  is an axial motor including a drive shaft  8  that penetrates a vertical support  4 A, a bearing  6 A, a rotor cam  18 , a support plate  46 , a rotor  48 , a cam support  50 , a stator cam plate  9 , a bearing  6 B, and a vertical support  4 B. The vertical supports  4 A and  4 B are fixed to and supported by a base  2 , with a gap left relative to the drive shaft  8 . The stator cam plate  9 , stator support  50 , rotor  48 , rotor support plate  46 , and bearings  6 A and  6 B are externally fitted over and fixed to the drive shaft  8 . 
         [0021]    The rotor  48 , stator  47 , shafts  12 A,  12 B, and  20 , support plates  29  and  46 , shafts  41 A and  41 B, shaft  43  are all made from non magnetic material. 
         [0022]    The fixed stator magnets  11  as shown in  FIG. 2  are arranged with their pole faces in a radial orientation having their S-pole facing inward towards the rotor magnets  36 A and  36 B. 
         [0023]    The rotor magnets  36 A and  36 B are arranged to have their N-pole facing outward. The main stator magnet  26  has its S-pole facing inward. 
         [0024]    Referring to  FIG. 5 , the stator cam follower  32  runs in a groove within the stator cam plate  9 . The cam follower  32  is rotatably mounted to the gear  34 . The gear  34  is rotatably mounted to the shaft  43 , and is meshed with the gear  28 . The stator shaft  20  is fixedly attached to the stator gear  28 . The cam profile in the stator cam plate  9 , is responsible for positioning the main stator magnet  26  by ultimately causing the rotation of the stator shaft  20 , to which the main stator magnet  26  is fixedly attached. 
         [0025]    Referring to  FIG. 5 , the rotor cam followers  40 A and  40 B runs in a groove within the rotor cam plate  18 . The cam followers  40 A and  40 B are rotatably mounted to their respective gears  44 A and  44 B. The gear  44 A is rotatably mounted to the shaft  41 A, and is meshed with the gear  24 A. The gear  44 B is rotatably mounted to the shaft  41 B, and is meshed with the gear  24 B. The cam profile in the rotor cam plate  18 , is responsible for positioning the rotor magnet  36 A and  36 B by ultimately causing the rotation of the rotor shafts  12 A and  12 B, to which the rotor magnets  36 A and  36 B are fixedly attached. 
         [0026]    Referring to  FIG. 2 , when one of the rotor magnets  36 A or  36 B is near any of the fixed stator magnets  11 , the attractive magnetic forces causes either of them to accelerate towards the main stator magnet  26 . Each successive fixed stator magnet  11  is larger in size and strength as they approach the main stator magnet  26 . This arrangement produces an increasing magnetic field in the direction of the main stator magnet  26 . In effect, a magnetic ramp is created causing a rotational torque to be applied to the rotor  48 . When the rotor magnet  36 A approaches the main stator magnet  26 , both of these magnets are independently rotated in unison in opposite directions until they are approximately parallel as shown in  FIG. 3 . As the rotor magnet  36 A passes by the main stator magnet  26 , it moves through an area of diminishing magnetic field strength, thereby encountering only a small cogging effect. The main stator magnet  26  is longer (distance between the north and south pole faces) than the rotor magnet  36 A, this feature is key to minimizing any cogging effect between the S-pole face of the stator magnet  26  and the N-pole face of the rotor magnet  36 A. Further, since the N-pole face of the main stator magnet  26  is curved away from the rotor magnet  36 A, very little cogging effect is transmitted to the rotor magnet  36 A as it passes. 
         [0027]    The main stator magnet  26  and rotor magnets  36 A and  36 B have full radius faces on their pole faces that are being used in attraction. This feature allows their full attractive magnetic forces to be used to aid in rotation of the rotor  48 . 
         [0028]    The advantages of the present invention include, without limitation, that it is able to rotate using permanent magnets. Further, the novel magnetic gate formed by the preferred embodiment provides a low cogging means to separate two permanent magnets. 
         [0029]    In its broad sense, the present invention is a permanent magnet motor providing rotational torque. 
         [0030]    The advantages of the present invention include, without limitation, that it is able to rotate using permanent magnets. Further, the novel magnetic gate formed by the preferred embodiment provides a low cogging means to separate two permanent magnets. 
         [0031]    Although the embodiment(s) of the device for providing rotational torque/permanent magnet motor  10  and method of use have been shown and described herein as providing a magnetic gate that allows continued motion of a rotor relative to a stator without an external power source, in alternative embodiments, the device for providing rotational torque/permanent magnet motor  10  and method of use include an external power source (e.g., to initiate rotation of rotor  48 , maintain rotational speed of rotor  48 , accelerate rotational speed of rotor  48 ). 
         [0032]    The above figures may depict exemplary configurations for the invention, which is done to aid in understanding the features and functionality that can be included in the invention. The invention is not restricted to the illustrated architectures or configurations, but can be implemented using a variety of alternative architectures and configurations. Additionally, although the invention is described above in terms of various exemplary embodiments and implementations, it should be understood that the various features and functionality described in one or more of the individual embodiments with which they are described, but instead can be applied, alone or in some combination, to one or more of the other embodiments of the invention, whether or not such embodiments are described and whether or not such features are presented as being a part of a described embodiment. Thus the breadth and scope of the present invention, especially in any following claims, should not be limited by any of the above-described exemplary embodiments. 
         [0033]    Terms and phrases used in this document, and variations thereof, unless otherwise expressly stated, should be construed as open ended as opposed to limiting. As examples of the foregoing: the term “including” should be read as mean “including, without limitation” or the like; the term “example” is used to provide exemplary instances of the item in discussion, not an exhaustive or limiting list thereof; and adjectives such as “conventional,” “traditional,” “standard,” “known” and terms of similar meaning should not be construed as limiting the item described to a given time period or to an item available as of a given time, but instead should be read to encompass conventional, traditional, normal, or standard technologies that may be available or known now or at any time in the future. Likewise, a group of items linked with the conjunction “and” should not be read as requiring that each and every one of those items be present in the grouping, but rather should be read as “and/or” unless expressly stated otherwise. Similarly, a group of items linked with the conjunction “or” should not be read as requiring mutual exclusivity among that group, but rather should also be read as “and/or” unless expressly stated otherwise. Furthermore, although item, elements or components of the disclosure may be described or claimed in the singular, the plural is contemplated to be within the scope thereof unless limitation to the singular is explicitly stated. The presence of broadening words and phrases such as “one or more,” “at least,” “but not limited to” or other like phrases in some instances shall not be read to mean that the narrower case is intended or required in instances where such broadening phrases may be absent.