DE69213923T2 - Magnetic motor with an eccentric rotor - Google Patents

Description

This invention relates to a magnetically actuated eccentric motion motor having a rotor that rolls within a stator.

Electric motors typically consist of a fixed stator and a rotating rotor between which electromagnetic forces are produced to cause the rotor to rotate. The rotor is fixed or supported by bearings to maintain a certain spacing between the rotor and the stator and this naturally gives rise to friction. Also, the further the spacing between the rotor and the stator, the weaker the electromagnetic forces.

A number of proposals have been made for a motor or actuator in which a rotor or rolling device rolls inside a cylindrical cavity as a result of electromagnetic forces. The electromagnetic forces are produced in a certain sequence around the circumference of the cavity to attract the rotor, which is made of a ferromagnetic material. See, for example, U.S. Patent Nos. 2,561,890, 4,728,837 and 4,482,828, German Patent No. DAS 1132229 and Swiss Patent No. 159,716.

Japanese document JP-A-62-89470 (see also Patent Abstracts of Japan, Vol 11, no. 288 (E-542) [2735], 17 September 1987) discloses a motor with eccentric motion in which a rotor with polygonal cross-section is made to roll along a planar or convex path formed by a plurality of electromagnetic stator poles. Disadvantages of such prior art mechanisms are that the mechanisms are generally very bulky and heavy, cannot be easily miniaturised and have low energy densities. This bulkiness and weight arise from the requirement that the components of the Mechanism are capable of developing sufficient electromagnetic forces to properly operate the mechanism.

Electrostatic motors similarly generally comprise a stator and a rotor mounted to rotate near or within the stator, the forces of attraction therebetween being electrostatic rather than electromagnetic. Examples of electrostatic motors are shown in U.S. Patent Nos. 735,621, 3,297,888, 3,517,225 and 4,225,801. In a recently published U.S. Patent No. 4,922,164, an eccentric motion electrostatic motor is described in which a cylindrical rotor is arranged in rolling engagement with a hollow cylindrical stator. Elongated conductive strips are arranged in the inside wall of the cavity of the stator and are spaced circumferentially around the cavity. The conductive strips successively pick up electrical charges to thereby attract the rotor and cause it to roll in the cavity of the stator. The rotor may have a polygonal cross-section with the stator poles defining a polygonal closed path with the rotor having one side less than the path.

Electrostatic motors are much lighter in weight and potentially smaller in size than electromagnetic motors, but the attractive forces are generally weaker.

It is the object of the invention to provide an electromagnetic motor which can be easily miniaturized without compromising the strength of the attractive forces required for the described operation.

This object is achieved by a motor with eccentric movement having the features of claim 1.

Preferred embodiments are the subject of the various dependent claims.

The invention will become more apparent from the following detailed description, taken in conjunction with the accompanying drawings, in which:

FIG. 1 shows a perspective view of a magnetic motor with eccentric movement;

FIG. 2 shows a side cross-sectional view of the engine of FIG. 1;

FIGS. 3A, 3B and 3C graphically illustrate successive positions of a rotor rolling in a stator when electromagnets of the stator are alternately excited;

FIG. 4 shows a perspective and cross-sectional view of another embodiment of a magnetic eccentric motion motor made in accordance with the principles of the present invention;

FIG. 5 is a perspective, partially fragmented view of one configuration of an eccentric motion motor of the present invention that may be used as a pump;

FIG. 6 is a perspective, partially fragmented view of a magnetic eccentric motion motor having a stator with a substantially square cross section and a rotor with a substantially triangular cross section;

FIG. 7 is a perspective, partially fragmented view of another magnetic eccentric motion motor having a stator with a pentagonal cross section and a rotor with a square cross section;

FIG. 8 is a perspective, partially fragmented view of a magnetic eccentric motion motor having a stator and a rotor formed with a gear track and gear teeth, respectively;

FIG. 9 shows a perspective and cross-sectional view of another embodiment of a magnetic eccentric motion motor according to the principles of the present invention, wherein the rotor is formed as an electromagnet;

FIG. 10 is a perspective, partially fragmented view of another embodiment of an eccentric motion motor employing two rotors, one disposed within the cavity of the other;

FIGS. 11A and 11B illustrate perspective and side cross-sectional views, respectively, of an electromagnet wound with a ribbon conductor made in accordance with the principles of the present invention;

FIG. 12 is a perspective, partially fragmented view of a magnetic eccentric motion motor using four stators and four rotors to balance the transverse forces generated during operation of the motor;

FIG. 13 is a perspective partial cross-sectional view of a magnetic eccentric motion motor in which damping elements connect the stator of the motor to a motor housing to dampen the transverse forces generated by operation of the motor;

FIG. 14 is a perspective cross-sectional view of a magnetic eccentric motion motor including a balancing member attached to the rotor to balance the transverse forces generated by operation of the motor;

FIG. 15 is a perspective partial cross-sectional view of a magnetic eccentric motion mechanism for converting rotary motion into translational motion;

FIG. 16 shows a front view of yet another embodiment of an electromagnet suitable for use as a stator in a magnetic motor with eccentric motion;

FIG. 17 shows a front view of the electromagnet of FIG. 16, but with the electromagnetic coils wound around different parts of the structure;

FIG. 18 is a front view of an electromagnet constructed similarly to the electromagnets of FIGS. 16 and 17, but with a substantially square rotor path;

FIGS. 19A and 19B illustrate, respectively, a plan view of a flexible coupling and a side cross-sectional view of an eccentric motion magnetic motor employing an inverted conical rotor;

FIGS. 20A and 20B illustrate a side cross-sectional view and a plan view, respectively, of another embodiment of a magnetic eccentric motion motor using a conical rotor;

FIGS. 21A and 21B illustrate a side cross-sectional view and a perspective, partially fragmented view, respectively, of yet another embodiment of a tapered rotor of a magnetic eccentric motion motor;

FIGS. 22A and 22B illustrate a plan view and a side cross-sectional view, respectively, of another embodiment of a conical rotor of a magnetic eccentric motion motor;

FIG. 23 shows a perspective view of a coupling between a conical rotor and a rotor drive shaft of an eccentric motion motor;

FIG. 24 shows a perspective view of another embodiment of a coupling between a conical rotor and a rotor drive shaft of a motor with eccentric motion;

FIG. 25 shows a side cross-sectional view of another embodiment of a conical rotor of a magnetic eccentric motion motor with a non-wobbling shaft configuration;

FIG. 26 is a side cross-sectional view of a gear coupling mechanism of a magnetic eccentric motion motor made in accordance with the principles of the present invention;

FIGS. 27A and 27BZ illustrate a side cross-sectional view and an end view, respectively, of a flexible coupling mechanism for use in conjunction with magnetic eccentric motion motors of the present invention;

FIG. 28 is a side cross-sectional view of a magnetic eccentric motion motor having an adjustable gear ratio;

FIG. 29 shows a perspective side cross-sectional view of a magnetic eccentric motion motor with one embodiment of a commutator assembly; and

FIG. 30 shows a plan view of a magnetic eccentric motion motor with another embodiment of a commutator arrangement.

In FIG. 1, a magnetic eccentric motion motor is shown. The motor includes a stator 4 formed of four electromagnets 8a, 8b, 8c and 8d. Each electromagnet includes end pieces 12 and 16 formed on opposite ends of a core rod 20, all of which are made of a ferromagnetic material. Around each of the core rods is wound an electrically conductive coil wire, such as wire 24. The coils wound around each of the core rods are coupled to a commutator current source 28 which, in response to signals from a control unit 32, supplies electrical current to the coils in a predetermined order and with a predetermined polarity, as will be discussed briefly next. This means that the power source 28 supplies electrical current to the coils either in one direction or in the opposite direction or simply does not supply current to the coils, all of which are under the control of the control unit 32.

The end pieces, such as end pieces 12 and 16, of the electromagnet 8d are formed in the shape of arcs having an inner curved surface area, such as a surface area 36 of the end piece 12, which defines a portion of a curved path along the other end pieces over which an elongated, substantially cylindrical rotor 40 can roll. The rotor 40, which serves as the rotor of the motor, forms a permanent magnet having a north pole and a south pole as shown in FIG. 2. It will be appreciated that the rotor 40 is made of a suitable magnetic material as is well known in the art.

The inner curved surface areas of the end pieces of the electromagnets, such as a surface area 36, may advantageously be coated with a wear-resistant material, such as silicon nitride, to prevent that wear occurs between the rotor 40 and the surfaces of the end pieces.

A position sensor circuit 44 is coupled by conductors 48 to sensing elements 52, coupled between respective end portions of the electromagnets 8a, 8b, 8c and 8d and in the path defined by the inner curved surfaces of the end portions, as shown in FIG. 1. The sensing elements may illustratively be field effect transistor devices which receive a current from the position sensor circuit 44, and whose current flowing therethrough varies depending on the position of the rotor 40 and the known, predetermined applied voltage. In this manner, the position sensor circuit 44 can determine the location of the rotor 40 in the stator 4.

The position sensor circuit 44 signals the controller 32 identifying the position of the rotor 40, and the controller 32 in turn signals the collector power source 28 to supply electrical current to the appropriate electromagnet to produce both magnetic attraction and magnetic repulsion between selected ones of the electromagnets and the permanent magnet rotor 40. A graphical representation of an exemplary sequence for energizing the electromagnets 8a, 8b, 8c, and 8d to cause the rotor 40 to roll within the stator is shown in FIGS. 3A through 3C. Only one end of each electromagnet is shown in FIGS. 3A through 3C, with the instantaneous polarities of such ends being designated by the letters "N" (representing a north polarity), "S" (representing a south polarity), and "O" (representing a neutral or zero polarity). in FIG. 3A, the rotor 40, which represents a north pole end in FIG. 3A, is positioned against the end of the rotor 8b, which provides a south polarity. The end of the electromagnet 8a exhibits a north polarity and the end of the electromagnet 8c exhibits a south polarity. The rotor 40 is thus repelled by the end of the electromagnet 8a and is attracted by the ends of the electromagnets 8b and 8c. This forces the rotor 40 to move in a counterclockwise direction in the stator 4. In FIG. 3B, three of the ends of the electromagnets have changed polarities as shown, so that the rotor is now attracted to the ends of the electromagnets 8c and 8d, but is repelled by the end of the electromagnet 8d, so that the rotor continues its movement in the counterclockwise direction. Finally, in FIG. 3C, three of the end portions of the electromagnets have again changed polarities so that the rotor 40 is now repelled by the end portion of the electromagnet 8c and attracted by the end portions of the electromagnets 8d and 8a to continue a rolling motion of the rotor 40 in the counterclockwise direction. The magnetic forces generated at the opposite end of the motor to that shown in FIGS. 3A-3C would similarly cause the rotor 40 to roll in the direction shown in FIGS. 3A-3C.

Since the rotor 40 is in rolling contact, or in close proximity, with the curved inner surfaces of the ends of the electromagnets 8a, 8b, 8c and 8d, the magnetic forces developed between the rotor and the electromagnet are quite strong. Also, little friction results from the rotor movement since it is in rolling contact with the stator and is not supported by bearings. Furthermore, as described in U.S. Patent No. 4,922,164, gear reduction is achieved virtually without the need for special gearing.

In FIG. 2, the rotor 40 is represented by a flexible coupling mechanism or shaft 56 with a utility unit 60 driven by the rotation of the rotor. In this manner, the energy of the motor of FIGS. 1 and 2 is harnessed and utilized. Various designs of coupling mechanisms are fully discussed in U.S. Patent No. 4,922,164.

The control unit 32 could illustratively be a microprocessor or other memory device with a stored program currently available on the market, such as a DEC VAX-LAB or IBM PC. The commutator current source 28 could illustratively be a motor driven rotary switch comprising a contact or loop element which simultaneously connects a current source of an appropriate polarity to selected ones of the wire coils 24 in the appropriate sequence when the loop element is caused to rotate. Alternatively, the collector current source 28 could be a conventional electronic commutator capable of energizing the electromagnets in the appropriate sequence and with the appropriate polarity.

The position sensor 44 could illustratively be a power source for supplying power to each of the sensing elements 52 and a current detector or series of detectors for determining the current level, i.e. the amount of current to be passed through each of the sensing elements, and then a signaling circuit for signaling to the control unit 32 in an appropriate manner to identify which sensing element 36 of the rotor 40 is closest thereto.

Alternative sensing arrangements for the rotor position could include optical sensing, where the rotor 40 is arranged to roll in a hollow, cylindrical housing positioned centrally beneath the electromagnets, and where the interior of the housing is illuminated. Light passing through apertures arranged circumferentially around the housing would be monitored to determine the position of the rotor 40. It is obvious that if the rotor were in a position to cover certain of the apertures, no light would pass therethrough to thereby identify the rotor's location.

FIG. 4 is a perspective, partial cross-sectional view of another magnetic eccentric motion motor wherein a substantially cylindrical, hollow enclosure, or housing 104, is provided. At both ends of the enclosure 104, rails 108 and 112 are formed to permit rolling thereover of respective disks 116 and 120 mounted on respective ends of a rotor 124. A pair of ridges or ribs 128 and 132 are formed on the inner surface of the enclosure 104 to prevent axial movement of the rotor 124 since the inner diameter of the ribs is less than the diameter of the disks 116 and 120. Disposed on the interior of the enclosure 104 and spaced circumferentially therearound are a plurality of electromagnets 136.

Each electromagnet 136 includes end pieces 140 and 144, a core (in the form of a rod) 148, and a coil of wire 152 wound around each core 148.

The rotor 124 in the embodiment of FIG. 4 may either be a permanent magnet, as shown in the embodiment of FIGS. 1 and 2, or it may simply be formed of magnetically attractable material. If the rotor 24 is a permanent magnet, the sequence of alternating attraction and repulsion could of the rotor, as described in connection with FIGS. 3A through 3C, can be used to drive the rotor and cause the disks 116 and 124 to roll over the rails 108 and 112, respectively. If the rotor 124 is made of a magnetically attractable material, then the electromagnets 136 would simply be energized and de-energized in sequence to attract (not repel) the rotor 124 and in turn cause the disks 116 and 120 to roll on the rails 108 and 112. The provision of a permanent magnet rotor enables the generation of large attractive forces (as well as repulsive forces) as opposed to those possible if the rotor is simply made of a magnetically attractable material.

FIGS. 5, 6, 7 and 8 all illustrate end perspective views, partially fragmented, of various alternative configurations for rotor and stator design arrangements, with FIGS. 6 and 7 corresponding to the motor of the present invention. FIG. 5 illustrates a stator 204 having a type of hexagonal internal cavity 208 in which is disposed a rotor 212 having a star-shaped cross-section. The side walls of the internal cavity 208 are formed in conjunction with the rotor 212 so that points or ribs 216 of the rotor are maintained in continuous sliding contact with the side walls of the internal cavity as the rotor rotates. The walls of the stator 204 and cavity 208, shaped as shown to allow continuous contact as the rotor rotates, are known as gyros. Again, the rotor 212 is a permanent magnet and the stator 204 is composed of a plurality of electromagnets 220 (windings, power source, etc., are not shown to maintain simplicity of the drawing, however, the provision of such a structure could be similar to that shown in FIG. 1).

The motor configuration of FIG. 5 of the present invention could be used as a pump in which fluid would be introduced into the interior of the stator 204 at a particular location between the lands 216 of the rotor 212, and then as the rotor was caused to rotate, such fluid could be forced out of the stator at another location. For example, fluid could be introduced into an opening 224 if the rotor 212 were rotated so that the land 216a moved toward the opening. Then, as the land 216a from the opening 224 toward the opening 228, the fluid can be pushed out from the interior of the stator 204.

FIG. 6 illustrates a stator 234 defining an internal cavity 238 having a square cross-section. Disposed within the cavity 238 is a rotor 242 having a triangular cross-section. The stator 234 includes four electromagnets 246 disposed around the cavity 238 to alternately attract and repel the rotor 242 to cause it to progressively rotate (or roll) within the cavity. Disposed at the corners of the cavity 236 are a pair of rotor locating sensors 250 and 254 so as to be contacted as the rotor 242 moves within the cavity 238. When the rotor 242 contacts respective pairs of the sensors, a circuit is completed between corresponding conductors 258 and 260 and this condition is sensed by a position sensing circuit to provide information to the control unit which in turn controls the application of an electrical current from a collector current source to the electromagnets 246 as previously described.

FIG. 7 illustrates yet another motor configuration of the present invention in which a stator 304 defines a pentagonal cavity 306 in which a rotor 308, having a substantially square cross-section, is arranged to roll. The stator 304 includes five electromagnets 312 arranged circumferentially about the cavity 306 for selective energization to cause the rotor 308 to move in a step-like manner about the cavity 308. Rotor locating sensors (not shown) could also be provided between the electromagnets 312 to complete or close a circuit when the sensors are contacted by a corner of the rotor, as described for the embodiment of FIG. 6.

FIG. 8 illustrates an embodiment of a motor in which the inner cavity 324 formed by a stator 328 includes a series of splines 332 and grooves 336 formed on the inside wall thereof to extend longitudinally within the stator and are circumferentially spaced on the side wall. A rotor 340 is disposed in the cavity of the stator and includes gear teeth 344 extending longitudinally along the rotor and are circumferentially spaced therearound. with the teeth sized to fit into the grooves 336 and allow the splines 332 to be received in the spaces between the teeth. In the manner already described, the rotor 340 is caused to roll in the stator cavity 324 when the electromagnets 348 are selectively energized.

FIG. 9 illustrates an embodiment of a motor in which a stator 354 is formed from a plurality of elongated permanent magnets 358 arranged substantially parallel to one another and circumferentially around a cavity 362. Enlarged end pieces 358a and 358b are formed in the electromagnets 358 and are positioned adjacent to one another to define an interior space, arcuate tracks 366 and 370. Arranged within the cavity 362 to roll on the tracks 366 and 370 is an elongated, cylindrical rotor 374 made of a ferromagnetic material. A coil of wire 378 is spirally wound around the cavity 362 so that it is out of contact with the rotor 374 as it rolls on the tracks 366 and 370. The permanent magnets 358 are positioned so that adjacent end pieces 358a and 358b of the different permanent magnets provide different polarities. For example, the end pieces 358b provide a north polarity in the top permanent magnet and then provide a south polarity in the next permanent magnet, proceeding clockwise around the stator, followed by a north polarity again, and so on.

The motor of FIG. 9 is operated by supplying current of the selected alternating polarity to sequentially reverse the polarity of the rotor 374 and thereby sequentially attract and repel the rotor from the different permanent magnets 358 to cause the rotor to roll within the cavity 362. In the embodiment shown in FIG. 9, the rotor is shown as being attracted to the uppermost permanent magnet 358. With the polarities of the rotor 374 switching, the rotor would then be attracted to the next permanent magnet, proceeding in a clockwise direction, and would be repelled by the uppermost permanent magnet, etc. In this manner, the rotor 374 would be caused to roll on the rails 366 and 370 within the cavity 362 as described.

Although not shown, the rotor 374 could be formed with disks as shown in FIG. 4 to roll on special rails formed in a hollow enclosure as also shown in FIG. 4. This would of course prevent wear from occurring between the permanent magnets and the rotor 374.

The motor of FIG. 9 uses a simpler collector current source since only one coil of wire 378 needs to be switched between polarities, i.e., from one to the other and then back to the one, etc. Of course, when multiple electromagnets are used, as in connection with other embodiments of the invention, multiple coils are required and each of these coils must be selectively energized.

FIG. 10 illustrates an eccentric motion electromagnetic motor having a hollow cylindrical rotor 404 disposed within a cavity 408 of a stator 412 formed from a plurality of circumferentially positioned electromagnets 416. Disposed within the hollow rotor 404 is a solid cylindrical rotor 420 having a diameter less than the inside diameter of the rotor 404 to allow the rotor 412 to roll within the rotor 404. The rotors 404 and 420 are made of magnetically attractable material so that when the electromagnets 412 are energized in sequence, the rotors 404 and 420 are caused to roll -- the rotor 404 within the cavity 408 of the stator 412 and the rotor 420 within the cavity of the rotor 404. Both rotors 404 and 420 could be attracted to the same electromagnets at the same time, however, the rotor 404, which has a larger diameter than the rotor 420, would roll at a different angular velocity, thus creating two energy sources having different torques and speeds.

The rotor 404 is coupled by a coupling shaft 424 to a utility unit 428 which is driven by rotation of the rotor 404 and hence the shaft 424. The shaft 424 could illustratively be connected directly to the rotor 404 or could be connected to a crosspiece 432 (shown in dashed line) which bridges the end of the rotor. The rotor 420 is coupled by a coupling shaft 436 to a utility unit 440 as shown in FIG. 10. Figures 11A and 11B illustrate one embodiment of a conductor coil used in conjunction with the electromagnets of the present invention. The coil is constructed from a flat strip of conductive material 504 formed to extend in a spiral configuration as best seen in FIG. 11B (side cross-sectional view) around a core 508 of an electromagnet. Such a coil structure is quite compact, yet capable of carrying substantial amounts of current. The coil strip 504 would include a coating of insulation to prevent shorting in the coil, and electrical access to the conductive strip could be achieved by simply making an angled cut 512 to expose one end of the conductive strip through the insulation.

Figures 12, 13 and 14 illustrate in perspective, partially fragmented views, motor arrangements for damping or balancing the transverse forces produced by the eccentric motion of the motor rotors. FIG. 12 illustrates a housing 520 in which four motors 524 are arranged with eccentric motion at the corners of the housing. The electromagnets of the motors 524 are energized to cause the rotors thereof to move in symmetrically opposite directions for each pair of diagonally arranged motors so that the transverse forces produced by the motors are effectively cancelled. For example, the rotors of the motors 524 are all shown in positions closest to the corners of the housing 520; from this position the runners would be made to move to a position closest to the center of the housing and then back again to positions closest to the corners, etc., to allow cancellation of the transverse forces produced by the movement of the runners.

FIG. 13 illustrates an alternative arrangement for dampening the transverse forces produced in an eccentric motion motor made in accordance with the present invention. In this embodiment, a housing 540 is again provided and a motor is held in place in the housing by springs 548 or other suitable shock absorbing elements. With this arrangement, the transverse forces produced by the operation of the motor 544 are not balanced, but are simply dampened by the springs 548. Simpler Coil springs or more complicated shock absorbers, similar to those used in vehicles, could be used.

FIG. 14 shows a perspective, partially fragmented view of another embodiment of a balancing arrangement according to the invention. Here, a stator cavity 556 surrounded by a substantially cylindrical enclosure 560 is shown. Electromagnets (not shown) would be circumferentially disposed about the enclosure 560 to selectively attract and/or repel a cylindrical rotor 564 disposed within the housing. Mounted on each end of the rotor 564 are balancing bodies, one of which is shown at 568, the balancing bodies being pivotally mounted at a location coincident with the rotor's axis of rotation 572. The balancing bodies are thus free to pivot or rotate about the axis 572 as required to provide the desired balancing for the rotor. As shown, the balance body 568 extends from the mounting axis 572 across the runner 564 to a location on the side of the enclosure 560 opposite that occupied by the runner 564. The balance bodies could take a variety of shapes, but they would advantageously have a curved upper end so that they fit just inside the enclosure 560 so that any movement of the runner 564 would cause the balance bodies to slide against the inside surface of the enclosure and move in a direction to maintain their positions on the side opposite the side covered by the runner. For example, if the runner 564 were caused to roll in a counterclockwise direction, the balancer 568 would move in the counterclockwise direction (since the inner surface of the housing 560 would force the balancer in that direction) to thereby keep the runner 564 and the balancer on opposite sides of the enclosure. The movement of the runner 564 would thus be balanced, assuming that the combined weights of the balancers are approximately the same as the weight of the runner, and the transverse forces will be effectively cancelled.

FIG. 15 is a perspective partial cross-sectional view of an actuator for converting a rotational motion of a cylindrical slider 604 into a translational motion of two annular chucks 608 and 612. The slider 604 includes screw threads 616 and 620 at each of its ends, with two sets of screw threads of different sizes formed. A stator (not shown) would be positioned to surround the rotor 604 and to cause it to roll on the threaded rails 624 and 628 formed in the inner walls of the annular liners 608 and 612, respectively. As the rotor 604 rolls, the screw threads 616 and 620 of the rotor engage screw threads 624 and 628 of the annular liners 608 and 612, respectively, to cause the annular liners to move longitudinally relative to the rotor, as determined by the direction of the engaging screw threads and by the direction of rolling of the rotor.

The annular chuck 612 is shown as being coupled by a coupling rod 632 to a utility unit 636 into which the rod can be moved or from which the rod can be pulled. In this manner, the rolling motion of the runner 604 is converted into a translational motion of the annular chuck 608 and 612 and such translated motion can be used to drive the utility unit 636.

Figures 16, 17 and 18 illustrate front views of stator structures which may be adapted for use in the motor of the present invention. Each of the stator structures includes an outer annular frame or ring 704 made of ferromagnetic material. Projecting radially inwardly from the ring 704 at circumferentially spaced locations are a plurality of projections 708, and on the inner end of each projection of the structures of Figures 16 and 17 is an arcuate portion 712 defining an arcuate surface area 716 which, together with the other arcuate portions, defines a substantially circular path interior of the circle. In the structure of FIG. 18, the inner ends of the projections 708 are formed with right angled corner portions 714 defining a square path 718. A substantially cylindrical magnetically attractable slider 720 is arranged to roll on the path formed by the bent portions 712 of FIGS. 16 and 17 when attracted in the manner previously described. In FIG. 18, a Runner 722 having a triangular cross-section arranged to "tilt" about path 718 in a stepped configuration.

Magnetic forces to attract and/or repel the rotor 720 are created in FIG. 16 by providing conductor windings on the circle 704 at locations between each adjacent pair of projections 708. For the embodiment of FIG. 16, there are four projections 708 and, consequently, four windings 724. By selectively energizing the windings 724, the arcuate sections 712 can be magnetically polarized to alternately attract the rotor 720 to cause it to roll in the path defined by the arcuate sections. Example polarities are shown in FIG. 16, where "S" represents a south polarity and "N" represents a north polarity.

In FIG. 17, a different winding arrangement is provided in which the windings 724 are wound around the projections 708 to enable selectively varying the magnetic polarity of the bent portion 716.

The circle 704 of FIG. 18 is wound similarly to that of FIG. 16 and the polarity of the projections 708 and hence the corner portions 714 are sequentially changed to cause the triangular-shaped rotor 722 to sequentially "walk" around the square path 718.

Illustrated in Figures 19A and 19B are a top view of a flexible coupling 804 and a side cross-sectional view of an eccentric motion magnetic motor using an inverted conical rotor 808, respectively. That is, the rotor 808 has a substantially planar top surface 812 and a concave conical bottom surface 816. The rotor 808 is made of ferromagnetic material as previously discussed with respect to the rotors of the other embodiments. The coupling 804 is made of a flexible material, such as spring steel, and is formed in the shape of a disk with a plurality of partially concentric openings 820 that allow for greater flexibility of the material. The coupling 804 is secured at the periphery of its bottom surface to an upwardly projecting web 824 formed on the top surface 812 of the rotor 808 at the periphery thereof.

The rotor 808 is arranged to orbit or rotate on top of a stator 828 which has a convex, conical top surface 838 and which includes a cylindrical housing 831 in which four electromagnets 832A, 832B, 832C and 832D (see FIG. 19A) are arranged. The electromagnets 832 are energized in sequence to thereby attract the rotor 808 in sequence to cause it to orbit and roll on the stator surface 830 in a circumferential manner. The electromagnet 832 includes a core 836 (FIG. 19B) around which a coil 840 is wound for periodically receiving an electric current to thereby develop a magnetic force for attracting the rotor 808. An iron end plate 844 is disposed in the bottom of the housing 831 to hold the cores and coils in place.

A drive shaft 848 is arranged to rotate within the stator 828. Mounted around the shaft 848 at the upper end thereof is a hub 852 to which a flexible coupling 804 is attached as shown in FIG. 19B. The shaft 848 is rotatably contained within an elongated bearing 856 disposed in the center of the stator 828. A retaining ring 860 is disposed at the bottom of the stator housing 831 to surround the shaft 848 and contact the end plate 844.

When the electromagnets 832 are sequentially energized, the rotor 808 is sequentially attracted to the electromagnets to orbit or roll on the stator 828, carrying with it the flexible coupling 804. The flexible coupling 804, in turn, is pivotally connected to the hub 852 to cause the hub and hence the shaft 848 to rotate as the rotor rotates. The rotor 808 orbits in a wobble-type action accommodated by the flexible coupling 804, but the shaft 848 is held in place in the stator housing to rotate about a fixed axis. In this manner, the orbiting rotor 808 drives the shaft 848 via the flexible coupling 804.

Commutation of the motor of FIG. 19B is accomplished by the rotor 808 successively contacting conductive contact elements 864 in the form of leaf springs spaced circumferentially around the stator housing 831 in the path of orbit of the rotor. As the contact elements 864 are successively contacted, electrical current is supplied to the next electromagnet in sequence in the direction of rotation of the rotor so that the electromagnet produces a force of attraction for the rotor to cause it to rotate in that direction, etc., as will be discussed more fully below.

FIGS. 20A and 20B illustrate an alternative embodiment of a conical magnetic eccentric motion motor, again in which a stator 904 is provided with four electromagnets 908A, 908B, 908C and 908D (see FIG. 20B). A rotor 912 formed with a substantially planar top surface 916 and a convex conical bottom surface 920 is arranged to orbit and roll on top of the stator housing 904 on a substantially flat top plate 910. A central tubular stub axle 924 is arranged to extend through the center of the rotor 912 and substantially perpendicular thereto. The lower end of the tubular stub axle 924 extends beneath the rotor 912 and into an opening 928 formed in the top plate 910 of the stator housing 904. An angled drive shaft 932 extends through the center of the stub axle 924 and then bends at the lower end of the stub axle to extend downwardly through the center of the stator 904. The drive shaft 932 is rotatable within the stub axle 924 and is rotatably held in place by bearings 936 and 940.

As with the embodiment of FIGS. 19A and 19B, when the electromagnets 908 are energized sequentially, the rotor 920 is attracted thereto so that the rotor orbits and rolls on the upper plate 910 in a circular motion, and with such circling, the drive shaft 932 is caused to rotate (at the same speed as the rotor's circular speed). The rotor 920 would be made of a ferromagnetic material, the upper plate 910 of a non-magnetic material such as brass or plastic, the stub axle 924 of a material such as brass or plastic, and the drive shaft 932 of a metal or metal alloy (to serve as a bearing).

Spaced circumferentially around the exterior of the stator 904 are four contact clips 944 which, when contacted by the rotor 912, receive current therefrom (from a power source not shown) and excite a next one of the Electromagnets in sequence to thereby cause sequential attraction of the rotor to orbit and roll on the upper plate 910. Various other commutation or collector arrangements will be discussed in greater detail later.

FIGS. 21A and 21B illustrate, respectively, a side cross-sectional view and a perspective, partially fragmented view of another embodiment of a magnetic eccentric motion motor utilizing a conical rotor 1004. Here again, the rotor 1004 includes a substantially planar top surface 1008 and a convex conical bottom surface 1012, but the apex of the conical surface is formed with a pivot ball 1016. The spherical pivot ball 1016 is rotatably disposed and held in place in a spherical pocket 1020 formed in the top surface of a top wall 1024 of a stator 1028. The conical surface 1012 of the rotor 1004 has formed thereon, at the periphery thereof, a ring gear 1032 surrounding the rotor. The ring gear 1032 is formed to mate with and roll sequentially on four partial ring gear segments 1036 that are spaced and arranged around the upper periphery of the stator 1028. Also disposed on the top wall 1024 of the stator is a conductor ring 1040 that maintains constant contact with the conical bottom surface 1012 of the rotor 1004 as the rotor orbits and rotates on the stator, as will be described shortly. Four electromagnets 1044 are disposed in the stator 1028 as in the conical rotor motors previously described.

A drive shaft 1048 in the form of a crank is pivotally coupled at its lower end to the top surface 1008 of the rotor 1004 and is held in a substantially fixed vertical orientation at its upper end by bearings 1052 and 1056.

In operation, the electromagnets 1044 are sequentially energized to thereby attract the rotor 1004 to cause it to pivot on the pivot ball 1016 and to sequentially orbit and roll over the partial ring gears 1036. This means that the ring gear 1032 sequentially contacts and rolls over the partial ring gears 1036 in accordance with the way the electromagnets 1044 When the rotor 1004 rotates, it causes the drive shaft 1048 to rotate to provide the desired drive power.

Commutation of the electromagnets 1044 is accomplished by supplying an electric current to the conductor ring 1040, which current is then supplied via the rotor 1004 (which is in constant, rolling contact with the conductor ring) to successive partial ring gears 1036 when those partial ring gears are contacted by the ring gear 1032. The partial ring gears 1036, in turn, supply current to respective electromagnets 1044 to energize such magnets and cause rotation of the rotor 1004.

FIGS. 22A and 22B illustrate a top plan view and a side cross-sectional view, respectively, of another embodiment of an eccentric motion magnetic motor. Again, four electromagnets 1060A, 1060B, 1060C and 1060D are provided in a housing 1062, on the top of which a conical rotor or runner 1064 is arranged to orbit. Gear teeth 1066 are formed on the bottom periphery of the runner 1064 to mesh with gear teeth 1068 formed on the top periphery of the housing 1062, similar to the conical runner embodiments previously described. A downwardly projecting ring 1070 is formed on the bottom surface of the rotor 1064 so as to be received in and orbit within a cavity 1072 formed in the top of the housing 1062. A drive shaft 1074 is pivotally formed at its upper end on the rotor 1064 and is rotatably held in place by bearings 1076 and 1078. Two exemplary arrangements for coupling the drive shaft 1074 to a tapered rotor are shown in FIGS. 23 and 24.

In FIG. 23, a conical rotor 1080 is shown coupled to a drive shaft 1082. An elongated cavity 1084 is formed in the top of the rotor 1080 with a central portion 1084A extending all the way through the rotor to receive the upper end of the drive shaft 1082. A crosspiece 1086 is disposed in a transverse opening in the drive shaft 1082 and is received in the cavity 1084 to prevent the drive shaft from sliding out of the central portion 1084A while allowing the drive shaft to about the axis of the crosspiece and about an axis orthogonal to the crosspiece. The cavity 1084 is formed to be large enough to permit pivotal movement of the drive shaft 1080 in the directions indicated so that the rotors 1082 are caused to orbit on a stator housing, whereby the drive shaft could remain in a substantially fixed vertical position in the stator housing.

FIG. 24 illustrates an alternative coupling arrangement between a rotor 1090 and a drive shaft 1091 in the form of a U-joint. The drive shaft 1091 extends through an opening 1092 in the rotor 1090 and is rigidly attached to a crossbar 1093 which extends diametrically across and is pivotally mounted on a ring 1094 surrounding the rotor. The crossbar 1090 is mounted to pivot on pins 1095A, 1095B which extend in diametrically opposite directions from the ring 1094 so as to permit pivoting of the drive shaft 1091 relative to the ring 1094. The ring 1094, in turn, is pivotally mounted to the rotor 1090 on pins 1096A and 1096B that extend in diametrically opposite directions from the rotor. The pivotal mounting of the ring 1094 to the rotor 1090 also allows the drive shaft 1091 to pivot about an axis defined by the linear axis of the pins 1096A and 1096B, as well as about an axis defined by the linear axis of the pins 1095A and 1095B. Accordingly, the drive shaft 1091 can be maintained substantially vertical while the rotor 1090 orbits on the upper surface of a stator housing, as previously described.

FIG. 25 illustrates a side cross-sectional view of another embodiment of a conical rotor of a magnetic motor. In this embodiment, a double-conical rotor 1104 (concave conical top and bottom surface with gear teeth) is provided to orbit and rotate on the conical top surface 1108 (with gear teeth) of the stator 1112. Again, successive energization of the electromagnets 1116 causes the rotor 1104 to orbit and rotate on the stator surface 1108, and as it does so, the upper conical surface of the rotor simultaneously contacts a conical gear 1120 to cause it to rotate. The conical gear 1120 is coupled at its upper surface to a drive shaft 1124 which is rotatable in a fixed position. is held by bearings 1128 and is coupled at its lower surface to another drive shaft 1132 which is rotatably held in place by bearings 1136. The bearings 1128 and 1136 and the stator 1112 are housed in a housing 1140.

FIG. 26 illustrates a gear coupling arrangement for coupling a rotor 1204 (which rotates in an embodiment of eccentric motion on rails 1208 of a stator 1212) to a drive shaft 1216. The drive shaft 1216 is pivotally connected to a coupling ring 1220, on the inside surface of which a ring gear 1224 is formed. The coupling ring 1220 is arranged to rotate in a ring bearing 1228 disposed in a housing 1232 of the stator 1212. Engaging gears 1236 and 1240 are formed on the rails 1208 and on disks 1244 of the rotor 1204, respectively. Similarly, a ring gear 1248 is formed around a forwardly projecting cylinder 1252 to engage the ring gear 1224. When the rotor 1204 is caused to move on the rails 1208 (by electromagnets as previously described but not shown in FIG. 3), the ring gear 1248 on the rotor's projecting cylinder 1252 engages and drives the ring gear 1224 of the coupling ring 1220 to cause the coupling ring to rotate. As the coupling ring 1220 rotates, the drive shaft 1216 is caused to rotate in a fixed, "non-orbiting" position. In this manner, the eccentric motion motor of FIG. 23 the drive shaft 1216 via a unique gear coupling mechanism.

FIGS. 27A and 27B illustrate another coupling arrangement of an eccentric motion motor for coupling an eccentrically rotating rotor 1304 to a drive shaft 1308. The drive shaft 1308 is rotatably supported in a fixed position by a bearing 1312 disposed in a housing 1316. The rotor 1304 includes a hollow bore 1320 through which extends a rod 1324 which is fixedly attached at one end to the center of a flexible disk 1328 which is attached to the rotor 1304 at various points on its circumference. The other end of the rod 1324 is pivotally connected to the center of a flexible disk 1332 which is attached to a rigid portion of the drive shaft 1308 at various points on its circumference. The disk 1332 and the ring 1334 are connected by a plurality of circumferentially spaced apart, rigid fingers 1336. Flexible disks 1328 and 1332 may be constructed similarly to flexible coupling 804 of FIGS. 19A and 19B. As rotor 1304 rotates within stator 1348, disk 1328 is caused to rotate, causing rod 1324 to rotate. As rod 1324 rotates, disk 1332 rotates and consequently coupling ring 1334 connected to drive shaft 1308 is caused to rotate, thereby driving drive shaft 1308 as desired. Because the disks 1328 and 1332 are flexible, the rod 1324 is allowed to pivot and operate relative to the drive shaft 1308 to transfer rotational energy of the rotor to the drive shaft via the rod.

FIG. 28 shows a side cross-sectional view of an eccentric motion motor having the adjustable gear ratio feature. A frusto-conical rotor 1404 is arranged to rotate in an eccentric motion within a stator 1408 as previously described. One end of the rotor 1404 is coupled to a flexible drive shaft 1412 which is slidably and rotatably held in place by bearings 1416.

The drive shaft 1412 can be moved longitudinally (as indicated by arrow 1420) to vary the depth of the rotor 1404 in the stator 1408 and thus vary the speed of rotation of the rotor. That is, when the drive shaft 1412 moves to the right as viewed downward in FIG. 28, the rotational speed of the rotor 1404 is increased, whereas when the drive shaft 1412 is moved to the left, the rotor 1404 moves further into the stator 1408 and the rotational speed is caused to decrease. In this manner, the gear ratio can be adjusted longitudinally by simply moving the drive shaft 1412.

FIG. 29 illustrates an illustrative commutator arrangement for the eccentric motion motors of the present invention. In this embodiment, a current source 1504 is coupled to a conductive rail 1508 in which one end of a rotor 1512 rolls. Current supplied to the rail 1508 flows into the conductive rotor 1512 and then to successive ones of the rail segments 1516 over which the other end of the rotor 1512 rolls. Current flowing through one of the rail segments 1516 flows to a respective electromagnet 1520 to cause the electromagnet to attract the runner 1512 and to cause it to roll within the rails 1508 and 1516. When the runner 1512 rolls out of contact with one of the rail segments 1516 and into contact with another of the rail segments, then a next, subsequent electromagnet 1520 is energized to attract the runner in the direction of the electromagnet to cause the runner to continue to roll. In this manner, commutation of the electromagnets 1520 is automatically provided when the runner 1512 is caused to roll.

FIG. 30 illustrates a schematic of a commutator arrangement for bi-directional rotation of a rotor 1604 within four conductive segments 1608 of a stator. Electromagnets 1612 are positioned adjacent to each of the segments 1608 to sequentially attract the rotor 1604 and cause it to roll within the stator. The electromagnets 1612 can be sequentially energized in either direction by a current source 1616 that supplies current to the conductive rotor 1604, which then supplies current to the stator segment 1608 of the rotor that is being contacted. From that stator segment, current flows to the electromagnet 1612 adjacent the stator segment 1608 toward which the rotor 1604 is rolling. For example, assume that the rotor 1604 is rolling in the counterclockwise direction and is in contact with the stator segment 1608a. In this position, current flows from the rotor 1604, through the stator segment 1608a and through a diode 1620 to the electromagnet 1612b. The electromagnet 1612b is thus energized to attract the rotor 1604 to cause it to continue its counterclockwise motion. For movement of the rotor 1604 in the clockwise direction, the polarity of the current source 1616 is simply changed.

Coupling the power source 1616 to the rotor 1604 could be accomplished by first coupling the power source to a conductive ring in which the rotor rolls and which maintains continuous contact therewith. Alternatively, disk contact elements can interrupt the power source to the rotor.

It should be understood that the arrangements described above are merely illustrative of the application of the principles of the present invention. Numerous modifications and alternative arrangements may be devised by those skilled in the art. relevant field of art without departing from the scope of the present invention as defined by the appended claims.

Claims (18)

1. Motor which moves eccentrically, comprising a stator with a plurality of electromagnets (246, 312) which are arranged in a field around an enclosed space, one pole of each electromagnet being arranged in series with the other pole to form a closed path, a rotor (242, 308) arranged to rotate along the closed path, the rotor being substantially rod-shaped and having a polygonal cross-section, means (28, 32) for selectively energizing the electromagnets to attract and/or repel the rotor and thus cause it to rotate along the path, the one poles of the electromagnets being formed to define a closed polygonal path and the rod having one or more fewer sides than the sides of the path, each of the electromagnets (246, 312) has a conductor (24, 504) wound around a core member (20, 508) for receiving an electrical current generated by an excitation device (28, 32), wherein the conductor (24, 504) comprises a flat strip of electrically conductive material helically arranged around the core and an insulating jacket surrounds the strip. 2. A motor according to claim 1, wherein the excitation means (28, 32) comprises means for energizing the electromagnets such that the one poles of the magnets alternately change polarities in a predetermined sequence to alternately attract and repel the rotor to cause it to rotate along the path. 3. A motor according to claim 2, wherein the rotor (40) comprises a permanent magnet and the excitation means comprises means for exciting the electromagnets (8a-8d) so that the one poles sequentially assume an attractive, neutral, repulsive, neutral, attractive, etc. state to cause the permanent magnet to rotate along the path. 4. A motor according to any one of claims 1 to 3, wherein the core element (20, 508) is arranged substantially parallel to the other core elements arranged around the circumference of the rod (40), the ends of the core element together with the ends of the other core elements being arranged to substantially surround the corresponding ends of the rod to sequentially attract and/or repel the rod to cause it to move along the path. 5. A motor according to any one of claims 1 to 4, wherein the rod is covered with a film of wear-resistant material. 6. Motor according to at least one of claims 1 to 5, wherein the path defined by the electromagnets (8a-8d) is covered with a film of wear-resistant material. 7. A motor according to at least claim 4, wherein each of the core elements (20, 508) of the electromagnets and the end pieces are formed of a ferromagnetic material. 8. Motor according to one of claims 1 to 7, further comprising a housing (540) for holding the stator and a damping device (548) arranged between the stator and the housing for damping the transverse movement of the stator when the rotor rotates therein. 9. A motor according to at least one of claims 1 to 8, wherein the motor further comprises a balance weight (568) mounted on one end of the rotor at a point coincident with the axis of rotation of the rotor and extending laterally to a location on the other side of the stator opposite the location where the rotor is located, thereby balancing and dampening the transverse forces exerted on the stator by the movement of the rotor. 10. A motor according to at least one of claims 1 to 9, wherein the excitation means (28, 32) comprises means which, in response to a rotor position signal, excites the electromagnets when the rotor is at a predetermined distance from the electromagnet in the direction in which the rotor rotates, thereby attracting the rotor towards those magnets, the motor further comprising sensing means (44) for determining the position of the rotor on the path of the stator and for applying a position signal to the excitation means to excite the electromagnets when the rotor is at a predetermined distance therefrom. 11. Motor according to one of claims 1 to 10, further comprising means (56) for coupling the rotor to a utilizing mechanism (60). 12. A motor according to claim 11, wherein the coupling device (56) is an elongated, transversely flexible shaft. 13. Motor according to claim 11, wherein the coupling device comprises: a substantially cylindrical extension (632) projecting from the rotor (604) and coaxial with the axis of rotation of the rotor, the extension having a toothed ring (628) formed around the circumference of the extension, a coupling ring (612) rotatably arranged to orbit the extension and rotate about a fixed axis, the coupling ring comprising a gear ring rotatably engaged on the inner circumference of the coupling ring with the gear ring of the extension as the runner rolls along the path, and a drive shaft (632) connecting the coupling ring to the utilizing device (636) for rotating coaxially with the rotation axis of the coupling ring. 14. Motor according to at least one of claims 1 to 13, wherein the stator comprises: a substantially circular frame (704) made of ferromagnetic material, and a plurality of projections (708) projecting substantially radially inwardly from the frame (704), the inner ends (714) of the projections being shaped to form a segment (718) of a closed, substantially polygonal path surrounding an interior space, the rotor (720) is arranged in the inner space to rotate along the closed path, and means for energizing the projections (708) of the stator to cause them to develop electromagnetic forces in a predetermined sequence and to cause the rotor to rotate along the closed path. 15. A motor according to claim 14, wherein the excitation device comprises: a plurality of wire coils (724), each of which is wound around the frame between a different pair of adjacent projections (708) and a device for selectively applying electric current to the coils. 16. A motor according to claim 14, wherein the excitation device comprises: a plurality of wire coils (724), each wound around a different one of the projections (708), and a device for selectively applying electric current to the coils. 17. A motor according to at least one of claims 1 to 16, wherein the rotor comprises a cylindrical rod (604) having screw threads (620) formed therein, the motor further comprising a chuck (612) having a threaded opening (628) having a larger diameter than the cylindrical rod so that the cylindrical rod (604) can be rotated along the closed path and the threads (620) of the rod engage along their circumference with the threads (628) of the chuck opening to cause the chuck (612) to move axially relative to the rod. 18. Motor according to at least one of claims 1 to 17, further comprising a working device (632) which is coupled to the chuck and operates when the chuck is moved.