US20010004171A1

US20010004171A1 - Linear electric motor

Info

Publication number: US20010004171A1
Application number: US09/788,917
Authority: US
Inventors: Wayne Griswold
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-02-05
Filing date: 2001-02-19
Publication date: 2001-06-21
Also published as: US6242823B1; WO2000046910A1; AU3478000A; US20010007400A1

Abstract

The present invention relates generally to linear electric motor, capable of converting electrical current into mechanical work. More specifically, this invention relates to an electric motor having a ferromagnetic vessel containing a single-pole magnetic field, and a shaft having an electromagnetic coil which moves relative to the magnetic field.

Description

BACKGROUND OF THE INVENTION

This application claims priority to U.S. patent application Ser. No. 09/245,184 filed on Feb. 5, 1999 now allowed.

The present invention relates generally to linear electric machines capable of converting electrical current into mechanical work. More specifically, this invention relates to an electric motor having a ferromagnetic vessel which contains a single-pole (or unipolar) magnetic field, electromagnets attached both above and below the single-pole magnetic field, end caps for reflecting (or repelling) magnetic energy and a shaft having an electromagnetic coil which moves relative to the magnetic field.

Electric motors, which generate mechanical energy from electric current, use the ability to create repulsive and/or attractive magnetic forces through the use of electromagnets to create movement.

Typically these electric motors require electromagnetic windings to move in and out of different magnetic fields in order to function. It is heretofore unknown in the art to design an electric motor where the electromagnetic windings are able to move solely within a single-pole magnetic field.

Additionally, despite the fact that movement of electric wires through magnetic fields is known to generate electric current, and electric motors have electric wires which move through magnetic fields, the ability to design an electric motor which, during at least some portions of its cycle can generate at least some of the current necessary to drive the motor is unknown. A motor which could generate a portion of the electric current necessary to drive it would be significantly more energy efficient than a conventional motor where such internal generation is not possible and would be a significant advancement in the art.

SUMMARY AND OBJECTS OF THE INVENTION

The present invention involves a linear electric motor. This motor creates a single-pole magnetic field within a ferromagnetic vessel. The single-pole magnetic field can be created either by permanent, typically radially-poled, magnets or electromagnets. The vessel typically contains ferromagnetic material or other materials which assist in maintaining or concentrating the magnetic field within the vessel. It is presently believed that these materials act in a way so as to reflect or repel at least some of the magnetic energy from the magnets back into the vessel. This arrangement of the magnets, all with the same pole oriented within the vessel, creates a region of concentrated magnetic energy within the field, typically at or around the center of the magnets. In other words, where the single-pole or unipolar magnetic field is a south pole field, a concentrated region of south pole magnetic energy exists, typically at or around the center of the magnets, within the south pole field.

Inside the single-pole magnetic field is positioned a shaft with an attached electromagnetic coil, the top and bottom of which are on opposite sides of the concentrated magnetic energy. Stationary electromagnets are placed within the vessel, one above and one below the single-pole magnetic field, and these electromagnets are electrically connected to the coil. End plates, either attached to the coil or the vessel, can also be used to increase the efficiency of the motor by assisting in maintaining or concentrating the magnetic field within the vessel. Presently it is believed that this maintenance of the magnetic field results from the reflection or repulsion of some of the magnetic energy back into the vessel.

To initiate movement of the coil, electric current is introduced into the coil creating an electromagnet with the top and bottom of the coil containing the north and south poles. Since the top and bottom of the coil are on opposite sides of the concentrated magnetic energy region of the field, the opposite forces created by repulsion of the coil's like pole and attraction of the coil's opposite pole to the concentrated magnetic energy within the field produces linear force to move the coil and shaft relative to the magnetic field. As the coil with its wire windings moves through the magnetic field, the movement of those wire windings through the field generates electric current. This generated current initially reduces the quantity of electrical energy or current required to maintain the electromagnetic field within the wire winding of the coil. As the speed of the shaft increases, the generated current even exceeds that required to maintain the electromagnet within the coil. When this excess generated electric current is created it is then fed into whichever stationary electromagnet the coil is moving towards thereby creating an additional magnetic force to pull the coil and its attached shaft in the desired direction.

As the top, or bottom depending on the shaft's direction, of the coil approaches the region of concentrated magnetic energy within the field, the current within the windings of coil is reversed and the current to the stationary electromagnet is turned off. This reverses the north and south poles in the coil and therefore reverses the forces on and direction of the shaft. Repetition of the cycle and maintenance of the shaft and coil within the field creates a motor whose electrical consumption necessary for creation of mechanical energy is considerably less than that of standard electric motors.

Accordingly, an object of the present invention is to create an electric motor capable of more efficiently producing mechanical energy from electric energy.

Another object of the present invention is to create an electric motor which has a region of concentrated magnetic energy within a single-pole magnetic field capable of interacting with an electromagnetic coil.

It is yet another object of the present invention to create an electric motor where the moving parts stay within a single-pole magnetic field.

It is yet another object of the present invention to create winding configurations in electromagnetic coils moving within a single-pole magnetic field which can optimize the magnetic forces between the electromagnetic coil and the single-pole magnetic field.

These advantages in addition to other objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. [0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

This invention provides for a linear [0015] electric motor 10, shown in FIG. 1. The linear electric motor 10 has a ferromagneteic vessel 12 having an interior cavity 14 which contains magnets 16. The vessel 12 can be an iron cylinder with other nonlimiting examples of additional ferromagnetic materials suitable for use within the vessel being ferrosilicates, cobalt, nickel and platinum group metals or any other material capable of concentrating the magnetic energy from the magnets 16 into the vessel 12. Further, the vessel may also employ magnetically reflective or repulsive coatings of different elements, typically containing at least some diamagnetic elements. These coatings typically will be placed along the inside surface of the vessel to create the same or similar properties or even improve on the properties found in solid metal vessels. These coatings will be specific depending on the different type of magnets 16 employed within the vessel 12. For example, it has been found that a combination, from inside coating to outside coating, of iron (unnecessary if the underlying vessel is an iron or iron containing material), copper, bismuth, lead and tin functions well with barium ferrite magnets and a combination, again from inside coating to outside coating, of iron, copper, tungsten, copper, aluminum, bismuth, lead and tin functions well with neodymium magnets. Additionally, one skilled in the art will also understand that no limitation as to a cylindrical shape of the vessel exists.
The [0016] magnets 16 are oriented such that a single-pole magnetic field is created inside the vessel's cavity 14. In the presently preferred embodiment shown in FIG. 2, the single-pole pole magnetic field is created by multiple radially poled permanent magnets 16A-16F arraigned around the inside surface of the cylindrical vessel 12. The inner surface 18 of each of the magnets 16A-16F contains a south magnetic pole, thereby creating a south magnetic pole field radially oriented into the center of the vessel 12. The outer surface 20 of each of the magnets 16A-16F will naturally then have a north magnetic pole. It is also within the scope of the present invention to create the single-pole magnetic field using electromagnets rather than permanent magnets.
It has been discovered that such a single-pole magnetic field within the [0017] vessel cavity 14 has a concentrated magnetic region at or around the middle 22 of the magnets 16 contained within the vessel 12. The exact dimensions of this concentrated magnetic region will vary depending such variables as the length of the magnets, the shape and width of the vessel, the type and strength of magnets and the reflective/repulsive magnetic properties of the vessel.
A [0018] shaft 24 having electromagnetic coil 26 attached moves in a linear, reciprocating cycle through the single-pole magnetic field. The use of magnetically reflective coatings around the shaft 24 has also been found to increase overall efficiency. In addition to the coating combinations already described, where stainless steel shafts are employed a combination of copper, iron and bismuth coatings has been found especially effective with barium ferrite magnets and a combination of aluminum and iron coatings effective with neodymium magnets.
In a preferred embodiment the [0019] electromagnetic coil 26 contains at least a two step winding configuration as shown in FIG. 3. In the first step the coil is wound into an hour-glass shape 28. After the hour-glass configuration is wound onto the shaft 24, a second step of filler windings 30 create the relatively uniform thickness electromagnetic coil 26. Additionally, choke windings can also be added over the outside of the filler windings 30. Wires 32 are attached to the coil 26 and allow current introduction into the coil and also allow generated current to exit the coil.
Above and below the magnets [0020] 16A-16F are stationary electromagnets 33A and 33B. These stationary electromagnets also contain wires which can accept current generated from the coil 26.
Additionally, [0021] end caps 34 are also used to reflect or concentrate magnetic energy back into the vessel cavity 14. These end caps can be placed on the top 36 and bottom 38 ends of the coil 26, as demonstrated in FIG. 3, or attached to the vessel 12 as shown in FIG. 1 where the point of attachment for the end caps 34 is at a point just above or just below the stationary electromagnets 33A or 33B. Typically, the end caps will contain ferromagnetic metals such as iron, cobalt, nickel and/or platinum, although polymer end caps are also capable of performing the desired function. Like the vessel 12 and shaft 24, the end caps 34 may also utilize elemental coatings in connection with solid metal or polymer caps.
FIGS. [0022] 4-6 demonstrate the linear reciprocating cycle of movement of the coil 26 through the magnetic field in an embodiment of the electric machine 10 functioning as a motor. In FIG. 4 the shaft 24 and attached coil 26 are oriented within a south magnetic pole field such that the top 36 and bottom 38 ends of the coil 26 are on either side of the concentrated magnetic region located around the middle 22 of the magnets 16. Electric current (i) is introduced into the coil 26 through the input wires 32 thereby creating an electromagnet in the coil with a north magnetic pole at the top end 36 of the coil 26 and a south magnetic pole at the bottom end 38 of the coil 26. Natural magnetic repulsion of the south pole at the bottom end 38 of the coil 26 with the concentrated south pole magnetic region of the magnets creates a downward force F1. Simultaneously, the attraction of the north pole at the top end 36 of the coil 26 with the concentrated south pole magnetic region also creates a downward force F2. These two downward forces, F1 and F2 then work in combination to move the shaft 24 down.
As the electromagnetic windings of the [0023] coil 26 move down through the south pole magnetic field, electric current is naturally produced in the wires of the coil. The quantity of generated electric current will be primarily function of the quantity and orientation of such variables as the windings within the coil 26, the strength of the single-pole magnetic field including the ability of the ferromagnetic vessel 12 and end caps 28 to maintain magnetic energy within the vessel cavity 14 as well as the velocity of the coil 26 within the single-pole magnetic field. As the coil 26 begins to move through the single-pole magnetic field electric current begins to be generated within the coil 26. This generated current initially reduces and ultimately eliminates the need of electric current input into the coil for a portion of the cycle as the generated current is able to maintain the electromagnet within the coil 26. In addition for a period of time during the cycle the movement of the coil 26 within the single-pole magnetic field generates excess current. When this excess current is generated, the current exits the coil through the input wire 32 and is then introduced into the stationary electromagnet 33B to create a north pole on the stationary electromagnet 33B which then creates an additional attractive force F3 which assists in driving the coil 26 down.
The [0024] shaft 24 and attached coil 26 continue through the south pole magnetic field until the top end 36 of the coil 26 approaches concentrated region of magnetic energy around the middle 22 of the magnets 16, as shown in FIG. 5. As the top end 36 of the coil 26 approaches the middle 22 of the magnets 16 the direction of the electric current (i) is switched and current to the stationary electromagnet 33B is turned off. This now creates a south magnetic pole at the top end 36 of the coil 26 which creates a repulsive force F4 which now acts to move the shaft 24 up. Simultaneously, the switch in the direction of electric current also creates a north magnetic pole at the bottom end 38 of the coil 26 which creates an attractive force F5 and which also acts to move the shaft 24 in an upward direction.
As the electromagnetic windings of the [0025] coil 26 move up through the south pole magnetic field, electric current is again generated in the wires of the coil. This generated electric current again maintains the electromagnetic north and south poles in the coil 26, thereby eliminating the need electric current input into the coil 26 for a portion of the cycle. In addition, for a period of time during the cycle the movement of the coil 26 within the single-pole magnetic field generates excess current. When this excess current is generated, the current exits the coil through the input wire 32 and is then introduced into the electromagnet 33A to create a north pole on the stationary electromagnet 33A which then creates an additional attractive force F6 which assists in driving the coil 26 up.
FIG. 6 shows the cycle completed and ready for repetition. As the [0026] bottom end 38 of the coil 26 approaches concentrated region of magnetic energy around the middle 22 of the magnets 16, the direction of the electric current (i) is again switched to its initial direction and the current to the stationary electromagnet 33A is turned off. This now recreates a south magnetic pole at the bottom end 38 of the coil 26, thereby recreating the repulsive force F1, and also simultaneously recreated a north magnetic pole at the top end 36 of the coil 26 thereby recreating the attractive force F2 and causing the shaft 24 to now be urged down again.
The repetition of the above linear reciprocating cycle can be readily accomplished by repeatedly switching the direction of the electric current (i) as the [0027] shaft 24 and coil 26 move through the single-pole magnetic field as shown in FIGS. 4-6. One skilled in the art will recognize that the mechanism used to switch the direction of the current (i) introduced into the coil 26 can take multiple forms. In a present embodiment shown in FIG. 7, a direct-current power source, typically comprised of batteries, 50 is connected to a controller 52 which switches the direction of the current (i) sent into the coil 26. A sensor 56 provides the input into the controller 52 indicating when the direction of the current (i) should be switched. This sensor 56, whether mechanical, optical, magnetic or otherwise, monitors the position of the coil 26 or the shaft 24 or any other component or property which indicates the position of the coil 26 within the single-pole magnetic field within the vessel 12. Functioning in conjunction with the controller 52 is a disconnect device 58. Since electric current input from the direct-current power source 54 into the coil 26 is not necessary through the entire cycle, the disconnect device 58 acts to stop or disconnect the flow of electric current from the controller 52 into the coil 26. Additionally the disconnect device 58 allows current generated within the coil 26 to exit the coil through the wires 62 and flow into either of the stationary electromagnets.
Inasmuch as standard alternating current is electric current with the direction of the current switched at a set frequency, as the RPMs of the linear reciprocating cycle increase the input current into the [0028] coil 26 from the controller 52 becomes more like a standard alternating current electric input. Consequently, at the proper speeds the machine 10 can function on standard alternating electric current input which then replaces the direct-current power source 50 and the controller 52, although the disconnect device 58 still acts to disconnect the input electrical current into the coil 26 while also allowing generated electrical current to exit the coil and go into the stationary electromagnets.
While the above embodiments describe the [0029] shaft 24 and coil 26 moving with respect to the stationary vessel 12 and magnets 16, one skilled in the art will recognize that the force created or electric current generated is a function of the movement of the shaft and its coil relative to the concentrated magnetic region created by the magnets. It is within the scope of the present invention to allow the magnets to move while holding the shaft and its coil stationary. Equally within the scope of the invention are embodiments where both magnets and shaft move relative to the other.
Additionally, the above description details a motor having one cavity and one single-pole magnetic field through which one shaft with attached coil moves. One skilled in the art will recognize that the scope of the present invention includes embodiments containing multiple cavities, with each cavity containing a single-pole magnetic field with a shaft and attached coil moving through that single-pole magnetic field. Typically such multiple cavity embodiments will contain at least one crankshaft to which multiple shafts with attached coils are connected. [0030]
Additional embodiments of the present invention employ a single cavity and a single shaft which passes through multiple single-pole magnetic fields contained within the cavity. The shaft in such an embodiment may contain a single elongated coil that moves through each single-pole magnetic field and/or multiple coils which each move within one single-pole magnetic field. [0031]
Although preferred embodiments of the invention are described herein in detail, it will be understood by those skilled in the art that variations may be made thereto without departing from the spirit of the invention or the scope of the claims. [0032]

Claims

What is claimed and desired to be secured by United States Letters Patent is:

1. A linear electric motor comprising:

(a) a vessel containing one or more magnetic elements, said magnetic elements arranged to produce a single-pole magnetic field;

(b) an electromagnetic coil which moves reciprocally within said single-pole magnetic field, wherein said reciprocal movement generates an electric current during at least a portion of said reciprocal movement;

(c) at least one electromagnet attached to said vessel;

(d) an electric circuit connected to said coil and said electromagnet which electric circuit allows at least a portion of said generated electric current from said coil to flow to said electromagnet.

2. The linear electric motor of

claim 1

wherein said electric circuit further provides for the introduction of electric current from an external source to said coil.

3. The linear electric motor of

claim 1

further comprising an end cap proximate to said coil.

4. The linear electric motor of

claim 1

wherein said vessel contains ferromagnetic materials.

5. The linear electric motor of

claim 1

wherein said unipolar magnetic field contains a region of concentrated magnetic energy.

6. The linear electric motor of

claim 1

further comprising a shaft connected to said coil.

7. The linear electric motor of

claim 6

wherein said shaft is connected to a crankshaft wherein the mechanical energy created by the movement of said coil is transferred to said crankshaft.

8. A linear electric motor comprising:

(b) an electromagnetic coil having a top and a bottom which moves reciprocally within said single-pole magnetic field, wherein said reciprocal movement generates an electric current during at least a portion of said reciprocal movement;

(c) a first electromagnet attached to said vessel above said coil;

(d) a second electromagnet attached to said vessel below said coil;

(e) an electric circuit connected to said coil and said electromagnet which electric circuit allows at least a portion of said generated electric current from said coil to flow to said electromagnets.

9. The linear electric motor of

claim 8

further comprising a first end cap proximate to the top of said coil and a second end cap proximate to the bottom of said coil.

10. The linear electric motor of

claim 8

11. A linear electric motor comprising:

(a) at least two separate vessels each of said vessels containing one or more magnetic elements, said magnetic elements arranged to produce a unipolar magnetic field;

(b) an electromagnetic coil disposed within each of said magnetic fields, said coils moving reciprocally within each of said magnetic fields, wherein said reciprocal movement generates an electric current during at least a portion of said reciprocal movement;

(c) a shaft connected to each of said electromagnetic coils;

(d) a crankshaft connected to each of said shafts;

(e) at least one electromagnet attached to each of said vessels;

(f) an electric circuit connected to each of said coils and each of said electromagnets which electric circuit allows at least a portion of said generated electric current from said coils to flow to said electromagnets.

12. The linear electric motor of

claim 8

wherein said electric circuit further provides for the introduction of electric current from an external source to said coils.