Abstract
A high torque axial gap electric motor includes rotor and stator disks containing magnets fixed to their respective faces, where the magnets contain triangular ridges arranged in concentric circles. The face of each rotor magnet ridge is parallel to the face of a stator magnet ridge, creating an air gap with a cross-section that has a zigzag appearance. The preferred embodiment uses a three-phase motor design with multiple rotors and stators and permanent magnets.
Claims
1. An electric motor comprising: a disk shaped rotor having a first face and a second face, angularly fixed to an output shaft; a disk shaped stator having a first face and a second face fixed to a support assembly; said second face of said rotor oriented towards and parallel to said first face of said stator; one or more bearings mounted between said output shaft and said support assembly, allowing said rotor and output shaft to rotate independently of said support assembly; a multitude of rotor magnets having a flat side mounted to said second face of said rotor and a ridged side of one or more triangular cross-section ridges opposite said flat side; a multitude of stator magnets with a flat side mounted to said first face of said stator and a ridged side of two or more triangular cross-section ridges opposite said flat side, said ridged side oriented so that the surface of said stator magnet ridges are parallel to the surface of said rotor magnet ridges.
2. The electric motor of claim 1 where said ridged side of said rotor magnets comprises two triangular cross-section ridges arranged in concentric circles from the axis of said output shaft.
3. The electric motor of claim 2 where said ridged side of said stator magnets comprises three triangular cross-section ridges arranged in concentric circles from the axis of said output shaft.
4. The electric motor of claim 3 where said ridged side of said rotor magnets comprises flat surfaces with an angle between 20 and 36 degrees to an adjacent flat surface.
5. The electric motor of claim 3 where said ridged side of said rotor magnets comprises flat surfaces with an angle of 30 degrees to an adjacent flat surface.
6. The electric motor of claim 5 where said rotor magnets comprise Neodymium.
7. The electric motor of claim 6 where said stator magnets comprise Neodymium.
Description
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
(1) FIG. 1 is a side view of the invention with the dust cover removed.
(2) FIG. 2 is a sectioned side view of the invention with the dust cover installed.
(3) FIG. 3 is a perspective view of a rotor magnet.
(4) FIG. 4 is a side view of a rotor magnet.
(5) FIG. 5 is a front view of a rotor showing the magnet arrangement on the rotor face.
(6) FIG. 6 is a perspective view of a stator magnet.
(7) FIG. 7 is a side view of a stator magnet.
(8) FIG. 8 is a front view of a stator showing the magnet and windings arrangement on the stator face.
DETAILED DESCRIPTION OF THE INVENTION
(9) In FIG. 1, is a side view of the invention comprising a first rotor 10, a second rotor 11, a third rotor 12, a first stator 13, a second stator 14, a support structure 15, a first bearing 16, a second bearing 17 and an output shaft 18. Each rotor and stator is disk shaped with two flat opposing faces and is constructed from a non-magnetic material. Permanent magnets with two ridges (rotor magnets) 19 are affixed to each rotor face opposite a stator face and arranged in a circle about the axis of rotation. The rotor magnets 19 are preferably Neodymium N50 magnets, a strong rare earth magnet. While N50 magnets represent the preferred embodiment, other types of magnets may be substituted depending on the torque output needed from the motor. The rotor magnets 19 can be mounted using fasteners or an adhesive.
(10) In FIG. 2 is a sectioned side view of the invention shown with a dust cover 30 installed. As seen in this view, the stator contains windings 21 comprising wire wrapped through the stator disk. There are three phases of windings in the preferred embodiment. Each winding 21 is recessed into a groove on the face of each stator and a stator magnet 20 is affixed to each winding. The stator magnets can be made of the same classes of magnetic material as the rotor magnets. The stator magnets can be mounted to the face of the stators using fasteners or adhesives as well, however the stator magnets must have a low resistance electrical connection to its corresponding winding 21.
(11) The dust cover 30 is attached to studs 31 that are attached to the outer ring of bearing 17 using nuts 32. Extending from the inside of the dust cover 30 are eight fully threaded rods 33. The rods 33 pass through smooth circular openings 34 in the stators 13 and 14, the cover 30 and the support structure 15. Each rod 33 is fixed to the dust cover 30 on one end with a nut 36 and fixed to the support structure 15 at its opposite end using a nut 36. The stators 13 and 14 are fixed to the rod 33 using nuts 36 tightened on either side of the respective stator.
(12) The sectioned side view of FIG. 2 shows the cross section of the rotor magnets 19, the stator magnets 20 and the air gap between them. The peaks 37 on the rotor magnets correspond to the valleys 38 in the stator magnets. The distance in the axial direction between the peaks 37 and the valleys 38 is between 1.2 and 3.0 mm in the preferred embodiment. Increasing the axial distance within these parameters increases the torque output of the motor and reducing the axial distance within these parameters decreases the torque output of the motor. It is understood that this particular range of distances is applicable only to the preferred embodiment, which uses a rotor of approximately 354 mm in diameter. The range in axial distances that are appropriate for a particular motor depend on the size of the motor, the strength of the magnet used and the angle of the peaks and valleys in the rotor and stator magnets respectively.
(13) FIGS. 3, 4 and 5 show the rotor magnets 19 and their arrangement on stator 10 in detail. While only one rotor is shown in this FIG. 5, it is understood that rotors 11 and 12 use an identical arrangement of magnets.
(14) FIG. 3 shows a perspective view of a single rotor magnet 19. The top edge of the rotor magnet 50 and bottom edge of the rotor magnet 51 are curved about the axis of the rotor. The peaks 37 are likewise curved about the axis of the rotor. The sides of the rotor magnets 52 are flat and perpendicular to the rotor surface and taper together towards the bottom edge of the rotor magnet 51. Therefore the top edge of the rotor magnet 50 is longer than the bottom edge of the rotor magnet 51.
(15) FIG. 4 shows a side view of a single rotor magnet. The peaks 37 have an angle 53. Changing the angle of the peaks adjusts the magnetic flux. The angle of the peaks 53 can be in the range of 20 to 36. Within this range, increasing the angle increases the torque output of the motor. In the preferred embodiment, the angle 53 is 30. FIG. 5 shows the rotor magnets 19 mounted on rotor 10.
(16) FIGS. 6, 7, and 8 show the stator magnets 20 and their arrangement on stator 13. While only one side of stator 13 is shown, it is understood that the opposite side of stator 13 and both sides of stator 14 use an identical arrangement of magnets.
(17) In FIG. 6, the top edge of the stator magnet 60 and bottom edge of the stator magnet 61 are curved about the axis of the stator. The valleys 38 are likewise curved about the axis of the stator. The curvature of the top edge of the stator magnet 60, the bottom edge of the stator magnet 61 and the valleys 38 are identical to the curvature of the top edge of the rotor magnet 50, bottom edge of the rotor magnet 51 and peaks 37 respectively. The sides of the stator magnets 62 are flat and perpendicular to the stator surface and taper together towards the bottom edge of the stator magnet 61. Therefore, the top edge of the stator magnet 60 is longer than the bottom edge of the stator magnet 61.
(18) In FIG. 7, the angle 63 of the valleys 38 is equal to the angle 53 of the peaks 37 in the rotor magnets 19 in FIG. 4. In the preferred embodiment, the angle 63 is 30.
(19) FIG. 8 shows the stator magnets 20 arranged on the stator 13. The windings 21 pass through an inner opening 70 and an outer opening 71 on the stator. Each winding 21 has a stator magnet 20 mounted above so that the winding 21 is pressed between the back of the stator magnet 20 and the face of stator 13. The preferred embodiment uses a three phase design so that there are three stator magnets for each rotor magnet.
(20) What has been described is an electric motor for the conversion of electrical energy to mechanical energy. It is well known in the art that electric motors can alternatively be used as generators, converting mechanical energy into electrical energy. While this disclosure shows the invention as an electric motor, it is also capable of being used as a generator. In this disclosure, there are shown and described only the preferred embodiments of the invention, but, as aforementioned, it is to be understood that the invention is capable of use in various other combinations and environments and is capable of changes or modifications within the scope of the inventive concept as expressed herein.
