WO2015040592A2

WO2015040592A2 - Electric motor and electric generator

Info

Publication number: WO2015040592A2
Application number: PCT/IB2014/064716
Authority: WO
Inventors: Kabu Walter MAKGERU
Original assignee: Makgeru Kabu Walter
Priority date: 2013-09-20
Filing date: 2014-09-21
Publication date: 2015-03-26
Also published as: ZA201602570B; WO2015040592A3

Abstract

The invention relates to an electric motor or generator having at least two concentric rotors. Each rotor is rotatable about its axis in an operative clockwise or anti- clockwise direction.

Description

ELECTRIC MOTOR AND ELECTRIC GENERATOR

FIELD OF THE INVENTION

The invention relates to an electric motor and electric generator BACKGROUND TO THE INVENTION

United States patent no US 20030193236 A1 in the name of Boris Maslov and Alexander Pyntikov discloses a rotary electric motor in which rotor and stator members are each configured as annular rings, concentric with respect to each other, about an axis of rotation. Either of the rotor or stator members is formed of groups of electromagnet poles, the groups substantially equidistantly distributed along the angular extent of the annular ring, each of the groups comprising magnetic material magnetically isolated and separated from the other groups. The other member comprises a plurality of permanent magnet poles substantially equidistantly distributed with alternating magnetic polarity along the angular extent of the radial air gap formed between the members, the permanent magnet poles having a common magnetic return path.

United States patent no US 7569970 B2 in the name of Honda Motor Co., Ltd. Discloses an electric motor comprising an inner periphery side rotor provided with inner peripheral permanent magnets with unlike poles, which are disposed alternately along a circumferential direction of the inner periphery side rotor, an outer periphery side rotor provided with outer peripheral permanent magnets with unlike poles, which are disposed alternately along a circumferential direction of the outer periphery side rotor, and a rotating device that varies a relative phase between the inner periphery side rotor and the outer periphery side rotor by rotating at least the inner periphery side rotor or the outer periphery side rotor around the rotational axis. The outer peripheral side rotor is arranged such that a rotational axis thereof is coaxial with a rotational axis of the inner periphery side rotor. The rotating device sets a variable width of the relative phase between the inner periphery side rotor and the outer periphery side rotor within a range of an electrical angle of below 180 °.

United States patent no US 2004015554 A1 in the name of Morgante John C. discloses a dual concentric AC motor allows for two independently operating AC motors that produce the same torque at the same current input as two conventional, separate electric motors while occupying a smaller physical volume. The dual concentric AC motor utilizes a single, hollow cylindrical stator core comprising inner and outer stators and an inner rotor and an outer rotor that operate independently of one another. The inner stator, with windings that face toward the center of the motor, couples to the inner rotor, which rotates inside the single stator core, while the outer stator, with windings that face away from the center of the motor, couples to the outer rotor, which rotates around the single stator core. A back iron, centrally located in the single stator core, physically and magnetically separates the inner and outer stators. The two rotors are coupled to separate, independent output shafts.

United States patent no US 6081059 A in the name of Hsu; Chun-Pu discloses an electric motor of outer-rotor type includes: an inner stator mounted on a stator holder, an outer rotor rotatably circumferentially disposed around the inner stator, a shaft coaxially secured with the outer rotor, and a housing combined with the stator holder for encasing the outer rotor and the inner stator within the housing; with the inner stator including an annular core made of magnetic conductor, a plurality of fin arrays made of magnetic conductors and formed as a fin array assembly concentrically wrapped on the annular core, and a plurality of insulating coil bobbins each coil bobbin pre-wound with the coil windings thereon and jacketed on each fin array, thereby forming an inner stator having a stable construction, a higher winding capacity, higher magnetic flux density and higher output power, as well as a lower production cost.

United States patent no US 3308318 the name of Raymond M. Dunaiski discloses a motor having contra-rotating armatures arranged for electrodynamics cooperation with a stationary field structure mounted in the frame of the motor.

Japanese patent number PCT/JP2003/003923 in the name of NISSAN MOTOR CO., LTD. discloses a rotary electric motor is provided which comprises an annular first rotor, an annular stator disposed concentric with and radially outside the first rotor, and an annular second rotor disposed concentric with and radially outside the stator, the stator including a stator core made up of a plurality of stator pieces that are arranged in a circular array and electrically independently from each other, coils wound around the respective stator pieces, annular first and second brackets disposed on opposite axial ends of the stator core, a fastening device passing through holes of the first and second brackets and fixedly holding the stator core between the first and second brackets, and an induction current suppressing device suppressing an induction current that is produced in response to a variation of magnetic flux of each of the coils and flows through the fastening device.

Chinese paten no CN 102347650 A in the name of FOSHAN NANHAI DISTR DONGTANG MOTOR FACTORY discloses an external rotor electric motor outer rotor assembly device it comprises outer shell outer rotor rotor shell the central hole and rotor shaft rotor shaft is concentrically and the size of the level section of rolling shaft the axle body head section is smooth round shaft than the outer rotor shell the center hole of head section the axle body big and small than the outer rotor shell in the centre hole of the shaft assembly the small head section can be the axle body there is no interference to pass through the outer rotor shell body the center hole of strong pressed into the rear big head section is smooth shaft body the outer rotor center of shell body hole is the interference fit with small head section of shaft body and it will not generate shape change is composed of a group of good concentricity high up-to-standard rate of the production cost is low the bonding force and firm the outer rotor of electric motor outer rotor assembly device is suitable for the alternating current direct current external rotor electric motor used in. The invention discloses an external rotor assembly apparatus of an external rotor motor. The external rotor assembly apparatus comprises: an external rotor shell, a center hole of the external rotor shell and a rotor shaft. The rotor shaft is a stack class shaft comprising a large and a small size of concentric shafts. A large part shaft is a smooth circular shaft and is larger than the center hole of the external rotor shell. A small part shaft is smaller than the center hole of the external rotor shell. During assembling to the shaft, the small part shaft can pass through the center hole of the external rotor shell without any interference. After being extruded with a strong force into the shaft, the large part smooth shaft can form tight interference fit with the center hole of the external rotor shell. The small part shaft can not generate deformation. A group of the external rotor assembly apparatus of the external rotor motor with good concentricity, a high passing rate, low costs and a firm bonding force is formed. The external rotor assembly apparatus is suitable for being used in various kinds of alternating-current and direct-current external rotor motors.

United States patent no US 6844648 B2 in the name of RELIANCE ELECTRIC TECHNOLOGIES, LLC discloses a winding pattern and technique for a stator of an electric motor is provided. The pattern is particularly well-suited for forming a four- pole, three-phase machine. The winding pattern permits concentric windings to be fully installed in slots of a stator core by machine in multiple steps. The concentric windings include windings which are singularly located within slots, and windings that share slots with other windings. The windings maybe inserted in the core slots by rotation of the core in an insertion station. Leads from the windings exit both ends of the core to facilitate channeling and termination of the windings.

Chinese patent no CN 202737612 U in the names of BAXTER ENERGY ELECTRIC CO., LTD.; ANHUI, CN; BAITE ENERGY SAVING MOTOR CO LTD; BAITE ENERGY-SAVING MOTOR CO., LTD.; BAITE ENERGY-SAVING ELECTRIC MACHINE CO LTD CN discloses a dual concentric winding electric machine stator it relates to the technology field which is to solve the problem that the cost is reduced the technology problem of. The electric motor the stator comprises stator iron core and is embedded in the stator iron core of the inner ring a plurality of stator winding wherein: Every stator winding is set with two winding; The same in the stator winding of the two winding coil and size of pitch is different and at the same core embedded. This utility model claims the motor stator can ensure motor performance at the same time of reducing motor cost. The utility model relates to a motor stator with double concentric windings, which belongs to the technical field of motors, and aims at reducing cost. The motor stator comprises a stator core and a plurality of stator windings embedded in an inner ring of the stator core. The motor stator is characterized in that each stator winding is provided with two winding coils; and the two winding coils in the same stator winding are different from each other in size and pitch, and are embedded in a concentric way. The motor stator provided by the utility model can reduce the cost of a motor while guaranteeing the performance of the motor.

Chinese patent no 20120293034 in the name of GM GLOBAL TECHNOLOGY OPERATIONS LLC discloses a stator for an electric motor includes first and second rows of conductors arranged concentrically around an axis inside a steel core. Each conductor includes a linking end. The stator also includes a first dielectric shim ring arranged between the two rows of conductors. Each conductor of the first row is bent in either a clockwise or a counter-clockwise direction relative to the axis and each conductor of the second row is bent in the opposite direction. The linking end of each conductor of the first row is attached to the linking end of an adjacent conductor of the second row after the conductors are bent. The first shim ring separates the first and second rows of conductors when the conductors are being bent, and is also at least partially disposed between the first and second rows of conductors when the linking ends are being attached.

OBJECT OF THE INVENTION

In is an object of this invention is to provide an electric motor and an electric generator of the type described above.

SUMMARY OF THE INVENTION In accordance with this invention there is provided an electric motor or generator having at least two concentric rotors.

Each rotor is rotatable about its axis in an operative clockwise or anti-clockwise direction.

There is provided for each rotor to be independently driven, alternatively for the rotors to be dependency driven with drive means.

An inner rotor may have a winding or may have permanent magnets.

An outer rotor may have permanent magnets or may have a winding.

In accordance with a second aspect of this invention there is provided an electric motor or generator having at least two concentric rotors and having at least a round tubular magnet, split in a plane extending through an axis thereof, in one of the rotors or in a stator of the motor or the generator.

There is provided for two such tubular magnets to be located end to end. There is further provided for a winding to extend out of the motor or generator and for the part of the coil extending out of the motor or generator to be exposed to a separate changing magnetic flux.

These and other features of the invention are described in more detail below. BRIEF DESCRIPTION OF THE DRAWINGS

One embodiment of the invention is described by way of example only and with reference to the drawings in which:

Figure 1 : shows a schematic view of a fist embodiment of an electric motor;

Figure 2: shows a perspective view of a second embodiment of an electric motor;

Figure 3: shows a perspective view of a third embodiment of an electric motor;

Figure 4: shows a perspective view of a fourth embodiment of an electric motor; Figure 5: shows a perspective view of magnets for the motor;

Figure 6: shows an end view of yet another embodiment of the motor; and

Figure 7: shows a perspective view of the embodiment of figure 6. DETAILED DESCRIPTION OF THE DRAWINGS

With reference to the drawings, a urinal anti-splash mat is generally indicated by reference numeral 1 . Figures 1 to 4 show schematic views of 4 different embodiments of an electric motor. Those skilled in the art would appreciate that what is shown in the drawings and described below could easily apply to an electric generator. Figure 1 shows a schematic cross sectional view of a stator and a rotor as is known in the art. However in this embodiment, the stator also rotates. The use of the word "stator" is thus incorrect. Instead, in this specification reference will be made to a second rotor. This will apply to all the drawings referred to herein. The embodiment shown in figure 1 thus has two rotors. The two rotors are mounted and supported by bearings allowing them to rotate about their own axis in both directions. The rotors can thus rotate in the same direction or in opposite directions to each other. The may be interconnected at their ends with a set of gears to regulate this relative movement. Alternatively they could be driven independently.

The inner rotor of figure 1 includes a winding of an electrically insulated but electrically conducting wire as is commonly known in the art. The outer rotor includes permanent magnets as is also known in the art. In figure 2 the winding and the magnets are swopped around so that the inner rotor includes the permanent magnets and the outer rotor has the magnets.

Figure 3 show an embodiment of an electric motor in which there are 3 rotors. The rotors are concentric and can rotate independently or dependently using gearing or other means. The rotors can be independently driven, The rotors can rotate in any one of the two directions about their respective axis.

Figure 4 shows an alternative embodiment to the embodiment shown in figure 3. In figure 3, the inner and outermost rotors include a winding and the central rotor includes permanent magnets.

In figure 4 this is reversed. The central rotor includes a winding and the inner and outermost rotor includes permanent magnets. In one embodiment of the invention, the rotors are independently driven by way of outer motors and pulleys and belts to which they are connected. Gears may also be used in this regard.

With reference to figure 5, a permanent magnet 10 in the form of a round tube is split along a plane through its axis so that the magnet has two halves 1 1 and 12. The split line 15 is clearly indicated in the drawing and could have non-conductive insulation material therein to keep the two halves slightly apart. Halves 13 and 14 of another such magnet is located end to end with magnet 10. These magnets, in the shape and configuration substantially as indicated could form part of the rotors or even of a stator.

Figure 6 shows the case where four such sets of magnets are located in a motor. Two halves 16 and 17 of a magnet are concentric with two halves 1 1 and 12. Of course, another similar magnet is located behind the halves 16 and 17. The magnet having halves 13 and 14 are located behind the halves 1 1 and 12 of a magnet.

The winding 18 is located in between the four sets of magnets. The winding 18 extends out of the motor or generator as can be seen in figure 7 and the part of the winding extending out of the motor or generator is exposed to a separate changing magnetic flux (not shown).

It will be appreciated by those skilled in the art that many other embodiments of the magnets are possible without departing from the scope of the invention.

It will be appreciated by those skilled in the art that many embodiments of the invention as a whole are possible without departing from the scope of the invention.

Claims

1 . An electric motor or generator having at least two concentric rotors.

2. An electric motor or generator as claimed in claim 1 in which each rotor is rotatable about its axis in an operative clockwise or anti-clockwise direction.

3. An electric motor or generator as claimed in any one of the preceding claims in which the rotors are independently driven or drive a load independently.

4. An electric motor or generator as claimed in any one of claims 1 to 3 in which the rotors are dependently rotatable.

5. An electric motor as claimed in any one of the preceding claims in which an inner rotor has a winding or permanent magnets.

6. An electric motor or generator as claimed in any one of claims 1 to 4 in which an outer rotor has permanent magnets or has a winding.

7. An electric motor or generator as claimed in any one of claims 1 to 4 in which an inner rotor has a winding and an outer rotor has permanent magnets or the inner rotor has permanent magnets and the outer rotor has a winding or both the inner and the outer rotors have windings or both the inner and outer rotors has permanent magnets.

8. An electric motor or generator comprising at least two concentric rotors and having at least a round tubular magnet, split in a plane extending through an axis thereof, in one of the rotors or in a stator of the motor or the generator.

9. An electric motor or generator as claimed in claim 8 in which two tubular magnets are located end to end.

10. An electric motor or generator as claimed in any one of claims 8 or 9 in which a winding extends out of the motor or generator and for the part of the winding extending out of the motor or generator to be exposed to a separate changing magnetic flux.