The present invention relates to an alternator which includes fixed coil disks subjected to a variable magnetic flux resulting from rotating magnetic disks and have an alternating emf induced in them. The coils' holding disk is manufactured from plastic material; no metallic cores are involved to hold the coils. Conductors are used to remove the power from the stationary coils, requiring no commutator or slip ring. The disk alternator of the present invention is based on the physical principle of electromagnetic induction, magnetic fields, conductors of the generating coils and movement. All three must be incorporated into a machine that generates current.
The advancements in alternator design improvement are becoming increasingly important, with continuing, increasing demands for lightweight, durable, alternator capable to operate at low and high speed, mainly for installations like windmills, diesel engines, reciprocating steam engines and many other similar power generators.
The present invention relates to a disk alternator that produces an alternating current output based, at least in part, upon the use of unique arrangement and configuration of permanent magnets and conductors—with no iron core—and which have a markedly different physical and mechanical configuration as compared with the conventional alternators.
Many devices exist which utilize a well-known principle that electric generators are rotating machines that transform mechanical energy into electrical energy. Basically, all alternators operate on the principle of electromagnetic induction, that is they work because a conductor is moving through a magnetic field, or a magnetic field is moving past a conductor and inducing a motional force “emf” in the conductors. These alternators typically have a closely wound, rectangular coil which rotates about an axis which is perpendicular to a uniform magnetic field provided by the electromagnets or by permanent magnets. The coils themselves are wound on an iron cylinder or armature, which can be fixed or rotating. The magnetic field is concentrated in the iron core. The speed of rotation is directly proportional to the frequency of the alternating current in most alternators. The armature, often called the stator, is the stationary member, and the magnetic field is rotating. The generated “emf” induced in coil is computed from the rate of change of magnetic flux through the core or from the velocities of the conductors traversing the magnetic field. This applies to any coil of any shape moving perpendicularly to a uniform magnetic field.
The changing magnetic fields will induce a magnetic field in a soft ferromagnetic core, magnetizing it and interacting with the coil conductors. The soft iron core is required only to support the coil and to conduct magnetic flux through the coil's conductors, and is not an operating member of current generation, unlike the magnetic flux itself. The iron core is actually a source of losses due to the heating, hysteresis and braking (cogging) of moving magnetic fields.
The presently built alternators, in order to be effective in power conversion, require a high speed of coil movement with respect to the magnetic field. However there are many plants having low operating speed, such as reciprocating power plants, steam or diesel engines, water or windmills, etc. In order to be effective, the output rotation of such power plants must be increased by various mechanical means, representing an additional source of losses and maintenance requirements.
Evaluation of existing alternator designs reveals a design whereby steel laminated cores are used to support the coils and create a flux conduction path forward to the next pole. Great care is used to reduce eddy currents, heat buildup, by stacking many insulated thin layers in these core components. They are essential in conventional alternators to conduct magnetic flux to the next pole, also to mechanically hold the coils. It can be said that the conventional alternators use polar coordinate design methodology. This concept has evolved over the last 100 years to the point where the technology is unchanged, but the industrial markets show a great need for the design of an alternator capable to operate at low and high speed.
Thus it is an object of the present invention to provide an alternator in which the magnetic flux of rotor's disk is maintained at its maximum and its stationary disk conductors have no ferromagnetic cores.
The disk alternator incorporates an innovative approach to the generation of an electromagnetic force. Basically the strategy switches from polar to rectangular coordinate generating “emf” not through angular flux conduction but linearly through the vertical axis. The disk alternator obtains its small air gap by stacking multiple thin disks supporting the conductor combination. The innovation is to eliminate the steel core and thus reduce eddy currents and all of the associated losses. Conventional alternators have changed very little since their conception. Changes have come in manufacturing techniques and improvements in material science only.
The present invention's goal is to fulfill the need for a cost effective alternator, designed to be reliable through all changing operating conditions, namely, that it should be able to withstand the runaway operation and work with minimal maintenance. It has been achieved through the unique design features as follows:
It is an object of the present invention to provide an alternator wherein the magnetic field strength is substantially uniform. It is another object of the present invention to provide a rotary magnetic device having substantially uniform magnetic polarity about the arc of travel. In accordance with a preferred embodiment of the invention, the power disk alternator comprises:
Further objects of the present invention will appear as the description proceeds.
The above mentioned and other features are objects of this invention, and the manner of attaining them will become more apparent and invention itself will be better understood by reference to the following description of a preferred embodiment of the invention taken in conjunction with accompanying drawings, wherein:
A disk alternator according to the present invention is a rotary magnet device composed of a rotor and stator disks designed to be direct driven, thus eliminating the need for costly gearboxes. The rotor means comprises rotating circular array disks with permanent magnets which are arranged in side by side relationship, disposed radially, outwardly from the rotor's axis, and which are arranged on the surface of the disk, with the surface of one magnet's polarity besides an opposite polarity of the neighboring magnet surface, thereby forming circumferentially, variable direction of the magnetic flux emanating from the surfaces of the magnets.
The rotating magnets disk poles form a gap between them with a generally uniform magnetic flux density there across.
The stator disks means includes one, two or more fixed, flat nonmetallic disks on the surface of which a predetermined number of flat conductors with no iron core are disposed radially outwardly from the disk's center.
One of the stator conductor disks can be disposed fixedly in the air gap formed by two rotating magnets disks. The second and the third conductor disks can be in the outside in relation to the rotating magnetic disks. The rotating magnetic disks move their magnetic fields in relation to the fixed power conductor (or stator) disks, and an alternating current is induced in the conductors.
This alternator that produces an alternating current output is based, at least in part, upon the use of unique arrangement and configuration of permanent magnets and conductors with no iron core, and which have a markedly different physical and mechanical configuration as compared with the conventional alternators. The disk alternator was invented to fulfill the need for a lightweight low speed alternator, mainly for installations like windmill power generators. Having an ironless construction, a large amount of weight, space and heat can be removed. Today's alternators must be operated at a relatively high speed to be efficient. However, as mentioned previously, industrial markets show a need for low speed alternators.
The invention disclosed herein maximizes the derivation of magnetic flux energy conversion into the induced electrical energy, and this from the stored energy stored in the interacting fields of the permanent magnets.
The rotor means rotate in direction (4) and are connected to a shaft, which is in turn connected to a power generating source.
The alternator of the present invention also includes at least one fixed stator means, comprising a disk having a circuit path on its periphery, as shown in
As mentioned previously, the rotating magnets move their magnetic fields (7) across stationary conductors mounted on the flat nonmagnetic disk. A series of conductors exposed to a uniform magnetic field with varying direction and rotating with constant angular velocity develops an alternating “emf”. When a number of pairs of magnetic poles are spaced around the circumference of rotating disks then each conductor on the fixed disk is swept across by the varying magnetic field (7) and a motional “emf” is induced in it, in one direction as the field's north pole passes the conductors, and in the opposite direction as the south pole is moved across the conductors. The induced “emf” is therefore alternating, and the number of complete cycles per each revolution equals the number of passing poles. The multiple structure of the magnetic poles enables a sufficiently high frequency to be attained without an unduly high velocity of rotation for the rotor disks.
In a preferred embodiment of the invention, the magnetic elements are angularly adjustable relative to each other to have maximum exposure of the magnetic elements between them and thus to maximize the magnetic field characteristic thereby controlling the degree of interaction between the magnetic fields (7).
Referring to
Although the above description refers to the rotor disks with their circular array of magnetized elements (1), these elements may be arranged in any geometric closed shape. The arrays of the elements (1) and (3) can be replaced by a solid, generally ring-shaped members. As shown in
While this invention has been described as having a preferred embodiment, it will be understood that it is capable of further modifications in the shape of the state conductors disk and rotor's magnetic disk and their orientation with respect to each other. Further modifications may be made in the construction materials for magnetic elements or otherwise to enhance operation or reliability or to reduce the cost. Accordingly, while the invention has been described with reference to a specific configuration, it is to be understood that this disclosure is to be interpreted in it broadest sense and encompass the use of equivalent apparatus.
Therefore this application is to cover any variation, use or adaptation of the invention following the general principle thereof and including such departures as come within known or customary practice in the art to which this invention pertains and falls within the limits of the appended claims.
Number | Date | Country | Kind |
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2,436,369 | Aug 2003 | CA | national |