Electromagnetic motor with secondary stator coils

An electromagnetic motor includes a stator assembly having a stator body with at least one pole, a primary coil associated with the stator body and electrically interconnected with a power supply such that electric current is the primary coil creates a magnetic field in the pole, a secondary coil associated with the stator body and magnetically coupled with the body and primary coil, and a permanent magnet armature positioned so that there is a working air gap between the armature and the pole. Termination of current flow to the primary coil results in a collapsing magnetic field that induces an electric current in the secondary coil to reverse the magnetic polarity at the stator pole, and thereby reverse magnetic attractive propulsion force in the armature.

The present invention relates to electromagnetic motors, and more 
particularly to an electromagnetic motor construction having a permanent 
magnet armature and a stator with both primary and secondary coils. 
BACKGROUND AND SUMMARY OF THE INVENTION 
Conventional dc electromagnetic motors are energized by application of 
electrical current to stator coils, which creates a magnetic field that 
forces an armature to move from a rest position. When the current to the 
primary coils of the electromagnetic motor is terminated, a collapsing 
magnetic field is momentarily created. Where it is desired to return the 
armature to its original position after the electric current is 
terminated, a mechanical spring may be utilized for such a purpose. In any 
event, energy of the collapsing field is essentially wasted. 
It is an object of this invention to provide an electromagnetic motor that 
employs the collapsing field caused by termination of stator coil current 
to move the armature to another position. It is a further object to 
provide electromagnetic motors that are of relatively simple and 
economical design, manufacture and assembly. 
An electromagnetic motor in accordance with preferred embodiments of the 
present invention includes a stator assembly having a stator body with at 
least one pole, a primary coil associated with the stator body and 
electrically interconnected with a power supply such that electric current 
in the primary coil creates a magnetic field in the pole, a secondary coil 
associated with the stator body and magnetically coupled with the body and 
primary coil, and a permanent magnet armature positioned so that there is 
a working air gap between the armature and the pole. In accordance with 
one important aspect of the invention, termination of current flow to the 
primary coil results in a collapsing magnetic field that induces an 
electric current in the secondary coil to reverse the magnetic polarity at 
the stator pole, and thereby reverse magnetic attractive/propulsion force 
on the armature. An important advantage is that the armature is positively 
moved by magnetic forces when current is terminated in the primary coil, 
resulting in a more efficient motor while reducing or eliminating any need 
for a return spring. 
The stator assembly in one embodiment of the invention comprises first and 
second stator bodies that are in spaced mirror symmetrical relationship. 
The first stator body has a pair of poles aligned with a pair of poles of 
the second stator body, and first and second primary coils are 
respectively disposed on the stator bodies. First and second secondary 
coils are respectively disposed on the stator bodies and 
electromagnetically coupled to the associated stator bodies and primary 
coils, and a rectifier is electrically connected to each secondary coil. 
When the electric current is terminated to the primary coils, a consequent 
collapsing magnetic field induces an electric current in the secondary 
coils, and this current is directed by the rectifier to reverse the 
polarities on the stator poles, which results in moving the armature to 
another position. This reduces the energy needed to move the armature to 
the opposite position. 
The stator assembly in a second embodiment of the invention includes an 
annular stator body having four orthogonally spaced poles. Four primary 
coils are disposed around respective poles, and four secondary coils are 
disposed around respective poles and electromagnetically coupled to the 
stator body and the associated primary coils. Each secondary coil is 
connected to a rectifier to direct the induced electric current in a 
direction to reverse the polarity in the pole on which the secondary coil 
is disposed. In this second embodiment, when the current is terminated to 
a primary coil, the consequent collapsing magnetic field induces an 
current in the associated secondary coil that reverses the polarity in the 
respective pole and provides added energy to assist in moving the 
armature. 
Other objects and features of the invention will become apparent in the 
following description and claims, in which the invention is described 
together with details to enable persons skilled in the art to practice the 
same, all in connection with the best modes presently contemplated for 
practicing the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
FIGS. 1 and 2 illustrate an electromagnetic motor 10 in accordance with a 
first embodiment of the present invention. Motor 10 comprises first and 
second stator assemblies 12, 14 with an armature 16 movably positioned 
therebetween. Stator assembly 12 comprises a one-piece stator body 18 of 
magnetically permeable construction having a base 20 with at least one 
pair of poles 22, 24 projecting therefrom. A primary electrical coil 26 is 
positioned between the pole pair 22, 24. Coil 26 is connected to a battery 
28 by a switch 30, and is wound around base 20. Stator assembly 14 is 
identical to stator assembly 12 and spaced from stator assembly 12 in 
mirror symmetrical relationship. Stator assembly 14 includes a stator body 
38 having a base 40 with a pair of poles 42, 44. Preferably, pole 42 is 
aligned with pole 22 and pole 44 is aligned with pole 24. Around base 40 
is a primary coil 46, which is wound in opposite spiral direction to 
primary coil 26. Therefore, if primary coil 26 is wound clockwise around 
base 20, primary coil 46 is wound counterclockwise on base 40. The coils 
26, 46 are interconnected at adjacent ends by a conductor 48. 
Each stator assembly 12, 14 also has a secondary coil 50, 52. Secondary 
coil 50 is wound around base 20, and is thereby electromagnetically 
coupled to body 18 and primary coil 26. Secondary coil 52 is wound around 
base 40, and is thereby electromagnetically coupled to body 38 and primary 
coil 46. The secondary coils 50, 52 each have a higher number of turns 
than do the associated primary coils 26, 46, and are wound in opposite 
spiral direction to associated stator coils 26, 46. Preferably, each 
secondary coil's windings axially overlap the windings of the associated 
primary coil. Opposite ends of secondary coils 50 and 52 are connected by 
two associated conductors 56, 58 to make a complete secondary coil circuit 
54. A rectifier 60 is interposed in conductor 56 to permit induced current 
to flow in only one direction through the secondary coil circuit 54. 
Armature 16 is of permanent magnetic construction, having ends 62, 64 of 
opposite magnetic polarity as illustrated in phantom. Ends 62, 64 are 
positioned between pairs of aligned poles 22, 42 and 24, 44 of stator 
assemblies 12 and 14. Both stator assemblies 12, 14 are mounted so that 
there is an air gap between projecting poles 22, 24 of body 18, or 
projecting poles 42, 44 of body 38, and armature 16. This mounting allows 
for limited travel of the armature 16 between stator assemblies 12, 14. 
Operation of electromagnetic motor 10 is illustrated in FIGS. 1 and 2. 
Initially, armature 16 is in abutting engagement with stator assembly 12 
and is held thereagainst by magnetic attraction between armature ends 62, 
64 and respective poles 22, 24 in absence of current through the primary 
coils. When switch 28 is closed to allow electric current to flow in the 
direction illustrated in FIG. 1 through primary coils 26, 46, this current 
creates a magnetic field that causes poles 22, 24 to have the same 
magnetic polarity as the adjacent ends 62, 64 of armature 16, and at the 
same time generates a magnetic field that creates opposite polarities in 
poles 42, 44 to those of the magnetic ends 62, 64 and aligned poles 22, 
24. That is, poles 22, 24 of stator body 18 are of "north" and "south" 
polarities, as are ends 62, 64, while poles 42, 44 of stator assembly 14 
are of "south" and "north" polarities. Thus, armature 16 is simultaneously 
magnetically attracted to stator assembly 14 and repelled by stator 
assembly 12 in the direction 66. Armature 16 is thereby moved from right 
to left in FIG. 1, and held in abutment with stator assembly 14 until 
current is interrupted or terminated to stator coils 26, 46. 
When current is interrupted or terminated to coils 26, 46 by opening switch 
28 (FIG. 2), consequent collapsing magnetic fields in coils 26, 46 induce 
a current in secondary coil circuit 54. This induced current causes the 
polarities in the poles 22, 24 and 42, 44 to reverse, which moves armature 
16 in the direction 68 back toward its original starting position. Poles 
22, 24 attract ends 62, 64 of armature 16, and poles 42, 44 repel ends 62, 
64 of armature 16. This secondary coil circuit thus supplements or 
replaces a mechanical spring for returning the armature to its original 
position. 
FIG. 3 illustrates a second embodiment 90 of an electromagnetic motor in 
accordance with the invention. This embodiment 90 comprises a stator body 
92, an armature 94 that is mechanically connected to a permanent magnet 96 
having a pair of adjacent hall elements 98, 100, and an electric switch 
circuit 102. Stator body 92 is of annular magnetic construction, having 
integral radially inwardly projecting orthogonally spaced poles 104, 106, 
108, 110. The first pair of poles 104, 106 are in mirror symmetrical 
relationship with their ends aligned with each other, and the second pair 
of poles 108, 110 are in mirror symmetrical relationship with their ends 
aligned with each other and perpendicular to the first pair of poles 104, 
106. Respectively disposed around each pole is a primary coil 114, 116, 
118, 120. All primary coils are interconnected to the electric switch 
circuit 102. Also respectively disposed around each pole adjacent to the 
associated primary coil are secondary coils 124, 126, 128, 130. Interposed 
in each secondary coil is a rectifier 134, 136, 138, 140 for preventing 
induced current from heating up the secondary coil while electric current 
flows through the adjacent primary coil. 
Armature 94 is mounted for rotation within stator body 92 and is positioned 
so that its radially polarized ends 150, 154 are spaced from the ends of 
the poles 104, 106, 108, 110, which are concentric with the axis of 
armature rotation. As the armature 94 rotates through 360.degree., magnet 
96 travels through the same rotational movement. Hall element 98 is 
positioned adjacent to one polarized end 152 of magnet 96 when armature 94 
is in alignment with poles 104, 106 and end 150 is adjacent pole 104. As 
shown in FIG. 3, when armature 94 has end 150 with a "north" polarity 
adjacent to pole 104, magnet 96 has an end 152 with a "north" polarity 
adjacent to hall element 98. Hall element 100 is positioned 90.degree. 
from hall element 98, preferably clockwise, so that when armature 94 has 
rotated counterclockwise 90.degree. and has end 151 adjacent to pole 110, 
member 96 has end 153 adjacent to hall element 100. These hall elements 
98, 100 work together with electric switch circuit 102 to energize the 
poles of the stator body 92 to magnetically repel and/or attract ends 151, 
152 of armature 94, resulting in rotation of armature 94. Electric switch 
circuit 102 comprises a power supply 150, hall elements 98, 100 and four 
transistors 156, 158, 160, 162. All of the elements of the electric switch 
circuit 102 are electrically interconnected and provide current to at 
least one pole on the stator body 92. 
In operation, if hall element 98 detects the "north" polarity of the 
adjacent end 150 of magnetic element 96, hall element 98 generates an 
electromotive force that turns on transistor 158 to supply current to 
primary coil 118 to create a south polarity on pole 108. At the same time, 
when armature end 152 leaves proximity of hall element 100, element 100 
terminates current to primary coil 114. This termination results in a 
collapsing magnetic field which induces a current in the adjacent 
secondary coil 124 that reverses the polarity of pole 104. This effect 
causes a repelling force between end 150 and pole 104 to combine with the 
attraction force between pole 106 and end 150 and continue 
counterclockwise rotation of armature 94 and mechanically connected member 
96. 
This rotation results in magnet 96 having its "south" polarized end 153 
brought to a position adjacent to hall element 100. This generates an 
output in hall element 100 that turns on transistor 160 and supplies 
current to primary coil 116, which causes pole 106 to have a "south" 
polarity thereby attracting end 150. Also, because no end of magnet 96 is 
adjacent to hall element 98, output voltage of hall element 98 is 
terminated. This interrupts current to primary coil 118, resulting in a 
collapsing magnetic field that induces a current in secondary coil 128 and 
reverses the polarity in pole 108 to a "north" polarity to repel end 150 
of armature 94. Again, armature 94 and magnet 96 are rotated 
counterclockwise resulting in the "south" polarity end 153 being adjacent 
to hall element 98 and thereby generating an output in hall element 98 
that turns on transistor 162 and directs current to the primary coil 120 
that causes a "south" polarity on pole 110. Pole 110 attracts end 150 to 
rotate armature 94 another 90.degree. counterclockwise. Concurrently, 
electric current is terminated to primary coil 116, resulting in a 
collapsing magnetic field and induced current in secondary coil 126. The 
secondary coil 126 reverses the polarity of pole 106 and repels end 150. 
This continuous switching of the electric current to an adjacent primary 
coil, and simultaneous termination of electric current to the preceding 
primary coil, causes the armature to rotate based not on just the 
attractive force of the adjacent pole but also on the repelling force of 
the preceding pole. This motor utilizes the energy of the collapsing 
magnetic field not previously harnessed, and results in a more efficient 
electric motor. 
It is also to be understood that, while the foregoing description and 
drawings illustrate in detail several embodiments of the invention, to 
those skilled in the art to which the present invention relates, the 
present disclosure will suggest many modifications in construction, as 
well as widely differing embodiments and applications, without thereby 
departing from the spirit and scope of the invention. The present 
invention therefore is intended to be limited only by the scope of the 
appended claims and applicable prior art.