PERMANENT MAGNET MOTOR WITH ENCLOSURE

Abstract

This disclosure relates to electric motors; the electric motor unit may include a rotor axially mounted on a shaft; the rotor may include a center lamination stack on a balance ring; the center lamination stack may have slots along its outer circumference that secure pole pieces attached to a plurality of magnets. The magnets may be located between the pole pieces and the center lamination stack. The magnets may not be fully contained within the metallic body of the rotor; the described rotor components may be contained in a wrapped fiber sleeve; the rotor is rotatably mounted within a stator.

Description

SHROUDED PERMANENT MAGNET MOTOR FIELD OF INVENTION This disclosure relates to electric motors and, more specifically, to the configuration of a rotor in an electric motor. BACKGROUND OF THE INVENTION The trend toward designing and building fuel-efficient, low- or zero-emission on- and off-road vehicles has increased dramatically in recent years, with a significant emphasis on the development of hybrid and fully electric vehicles. This, in turn, has led to a greater emphasis on electric motors, either as the sole source of propulsion (e.g., fully electric vehicles) or as a secondary source of propulsion in a combined propulsion system (e.g., hybrid or dual-motor electric vehicles). The electric motor in such an application may utilize an AC or DC permanent magnet motor design or an AC induction motor design. Regardless of the type of electric motor, motors are generally designed for a particular application to achieve the desired efficiency, torque density, or high speed and power output within an acceptable motor size and weight. BRIEF DESCRIPTION OF THE INVENTION This disclosure relates to electric motors. The electric motor unit includes a rotor mounted coaxially on a shaft. In one embodiment, the rotor may include a center lamination stack mounted on a balance ring. The center lamination stack may have slots along its outer circumference that secure pole pieces coupled with a plurality of pins. The pins may be located between the pole pieces and the center lamination stack. In one embodiment, the pole pieces may further comprise installation slots, such as a plurality of integrated locating pins projecting from the surface of the balance ring to secure the pole pieces during a sleeve winding process. In one embodiment, the described rotor components are contained within a wound fiber sleeve that holds the pieces in place around the rotor periphery.The rotor is mounted rotatably inside a stator to form a permanent magnet motor. frnocnn / eznz / q / uιλι BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows an illustrative axial partial cross-section of an electric motor, in accordance with certain modalities of this disclosure. Figure 2 illustrates a perspective view of an enclosed rotor, in accordance with certain modalities of the present disclosure. Figure 3 illustrates a perspective view of the components of a rotor contained within a rotor sleeve, according to certain modalities of this disclosure. Figure 4 illustrates an illustrative axial view of an enclosed rotor, in accordance with certain modalities of this disclosure. Figure 5A shows an exploded view of the internal components of a rotor, in accordance with certain modalities of this disclosure. Figure 5B shows a perspective view of a balance ring and rolling stack unit on an engine stem, according to certain modalities of this disclosure. Figure 6 illustrates a cross-section of a rotor, in accordance with certain modalities of this disclosure. Figure 7 illustrates a motor performance graph comparing motor speed with torque for both a conventional permanent magnet motor and a permanent magnet motor having a carbon sleeve, according to certain modalities of this disclosure. DETAILED DESCRIPTION OF THE INVENTION These variations relate to a permanent magnet motor with a rotor that has magnetic parts arranged around its periphery and held in place by a fiber wrapping wound around the rotor's outer circumference. For example, the fiber wrapping can be made of carbon fiber or other materials. In one variation, the magnetic parts are not held to the rotor by metallic components, and the magnets are not fully enclosed within the rotor. The magnetic fields created by a stator acting on the magnetic parts in the rotor can be stronger compared to conventional rotors with magnetic parts embedded in metal because the wound fiber wrapping, and the lack of metallic components, can provide a lower level of interference with the magnetic fields generated by the stator.In one embodiment, there are metallic components, either limited or not, arranged between the magnetic parts and the central portion of the rotor. Therefore, the permanent magnet motor disclosed here can offer improved performance compared to conventional designs due to reduced magnetic flux leakage. Figure 1 shows an axial cross-sectional view of a permanent magnet motor 100 according to one embodiment of the present disclosure. The illustration provided in Figure 1 is simplified for explanatory purposes; this view omits windings and other components. As shown, a rotor 101 is surrounded by a stator 103. A plurality of windings (not shown) are arranged around each of the stator teeth 109. In several embodiments, the windings are made of copper, but other materials are within the scope of the invention. The windings define a plurality of poles, for example, a three-phase, four-pole design, or a six-pole design. As shown, the rotor 101 is surrounded by the stator 103, the two separated by an air gap 105. A shaft 107 is coupled to the rotor 101. The shaft 107 provides a means of coupling the motor 100 to various devices and mechanisms, such as a shaft, gearbox, and the like within an electric vehicle. The air gap 105 between the stator 103 and the rotor 101 is sized to achieve a desired level of magnetic inductance from the stator 103 to the rotor 101. The air gap 105 can also affect the saturation levels and harmonic levels of the magnetic flux near the air gap 105. In general, the smaller the air gap 105, the stronger the magnetic flux between the stator 103 and the rotor 101. As shown, a series of magnets 111A and 111B are arranged in a V-shaped configuration around the periphery of the rotor 101. The configuration of magnets 111A and 111B has an apex 117 positioned toward the stem 107 and two arms 119A and 119B, which point toward the stator 103. The end of each of the arms 119A and 119B is adjacent to an opening 120A and 120B that provides a gap between the magnet arms and the air gap 105. This air pocket, or gap, allows the magnetic flux from the rotor to the stator to have minimal loss of permanent magnet flux. Magnets 111A and 111B are not integrated into a solid metal body of the rotor 101. It should be appreciated that the illustration is only an example of how magnets 111A and 111B may be oriented, and those 111A and 111B may be arranged differently in other modalities.A wound fiber sleeve 115 is shown surrounding the rotor to hold magnets 111A and 111B in place as the rotor 101 rotates within the stator 103. It should be understood that other magnet configurations in which the magnets are not fully contained by the rotor can also reduce permanent magnet flux loss. Figure 2 shows an assembled rotor 101 according to the invention. The rotor is contained within the wound fiber sleeve 115, unlike traditional iron bridges. The stem 107 is coupled to the rotor 101 and provides a means of coupling the motor to various devices and mechanisms, such as a shaft, gearbox, and the like, within an electric vehicle. In some embodiments, the wound fiber sleeve 115 comprises carbon fiber that is wound around the rotor while being pre-tensioned. In one embodiment, the sleeve has a thickness of 0.1 to 2 mm. In other embodiments, the sleeve has a thickness of 0.3, 0.4, 0.5, 1, 2, 3, 4, or 5 mm.Unlike existing methods for producing wound fiber rotor sleeves, the present wound fiber sleeve production method aims to minimize sleeve thickness by subjecting the fiber to relatively higher tension during the winding process. To minimize sleeve thickness, the fiber can be wound onto the rotor while already under tension. In some embodiments, the fiber can be wound using a unique guide pulley system with guide pulley rollers that can wind the fiber around the rotor's periphery under tension with minimal fiber damage. Figure 3 illustrates an illustrative embodiment of the fully assembled internal components of the rotor 101 (with the sleeve removed) according to this disclosure. The rotor 101 surrounds the stem 107 and comprises a balance ring 313 at the lower end, a central lamination stack 305, pole pieces 307, and mandrels 111A and 111B. The stem 107 has a coaxial disk 315 extending from the lower end of the stem 301. The coaxial disk 315 has one or more flat segments (planes) 303 around its circumference. The planes 303 function as a gripping area for the filament winding equipment during rotor manufacturing, specifically during the sleeve winding process where the filament winding equipment grips the stem to rotate the rotor. In some models, the disc may not have 303 flats and, instead, may have other gripping features, as appropriate for the filament winding equipment.In some configurations, the disc may lack flats or any other gripping features, resulting in an uninterrupted outer circumference. In this figure, the wound fiber sleeve is not shown around rotor 101. Continuing with reference to Figure 3, the central lamination stack 305 is mounted on the balancing ring 313. The central lamination stack 305 has a plurality of grooves 317 along its outer lateral edge, running the entire length of the central lamination stack 305. Each of the pole pieces 307 is coupled with a plurality of magnets 111. When assembled, the pole pieces 307 and the magnets 311 fit into the grooves 317 of the central lamination stack 305, such that the magnets 111 are pressed between the pole piece 307 and the central lamination stack 305. This can be seen more fully with reference to Figure 5 below. It should be noted that, in some embodiments, the pole pieces 307 and the central lamination stack 305 are not connected by a steel bridge or other metallic component such as frnocnn / eznz / q / uli in other conventional rotor designs.Removing all metal connections between the 307 pole pieces and the 305 center lamination stack reduces flow leakage through the connection. In some embodiments, each pole piece 307 has an installation slot 309 that is configured to interlock with a locating pin (not shown) on the balance ring. The installation slot 309 and the locating pin may serve as securing features during rotor fabrication. In some embodiments, the 111 mandrels, pole pieces 307, and the center lamination stack 305 are installed against each other during assembly. In some embodiments, the pole pieces 307 may not have installation slots 309. Due to the high speed at which the rotor components rotate during the winding process, the securing features may keep the pole pieces 307 close against the center lamination stack 305 during fabrication. In one embodiment, the sleeve winding process begins with placing the rotor shown in Figure 3 onto the rotating mechanism connected to a filament tensioning system, such as guide pulley rollers. For example, the tensioning system might include a carbon fiber spool that runs through an epoxy resin bath and is then wound onto the outer circumference of the rotor mechanism shown in Figure 3 as it rotates in one direction. In another embodiment, the tensioning system might apply resin to the spool during the dispensing process. This system allows the sleeve to be wound along the length of the rotor in a predetermined pattern and with a predetermined number of fiber wraps to create a specific sleeve thickness. It should be clear that the sleeve surrounding the rotor is not necessarily made of carbon fiber. Other similar materials can also be wound around the rotor and used to enclose it and maintain the positions of the pole pieces and handles. For example, other composites made from different types of fibers, such as ceramic, fiberglass, polypropylene, polyethylene, polyetheretherketone (PEEK), and similar plastics, can be embedded in a resin to form a durable material that can be used to create a tensioned sleeve around the rotor. In another example, a combination of materials, such as carbon fiber embedded in a plastic, can be used to make the sleeve. Figure 4 shows an axial cross-sectional view of a fully assembled rotor according to this disclosure. This unit is coaxial with the stem 107, as illustrated by the stem 107 running through the center of the rotor. From the axial view, the mandrels 111A and 111B can be seen pressed in alignment against both pole pieces 307 and against the center lamination stack 305. In some embodiments, the mandrels positioned on adjacent faces of a pole piece (for example, a pair of mandrels forming a V-configuration) are separated from each other by an air gap. Each pole piece 307 may comprise the installation groove 309, which is interlocked with a locating pin to secure the pole piece 307 during the winding process. The wound fiber sleeve 115 may contain the entire unit.Of course, it should be noted that the locating pin may not be required, and engine configurations may not include any locating pin or rods. Figure 5A shows a partial unit of rotor 101 according to this disclosure. In this partial unit, only the center lamination stack 305 and the balance ring 313 have been mounted on the stem 107. As illustrated, the locating pins 507 are integrated into the balance ring 313 and project beyond the face of the balance ring 313. A set of locating pins 507 may project a small distance from the face of the balance ring 313 that makes contact with the center lamination stack 305. Figure 5B shows an exploded view of the inner unit of a rotor, according to this disclosure. Figure 5B shows how pole pieces 307 and guides 111A and 111B can be fitted into a plurality of slots 317 and coupled to each other and to the center lamination stack 305. As illustrated, in some embodiments, guides 111A and 111B are installed on the pole pieces 307 but not on the center lamination stack 305, as shown in Figure 5B. In one embodiment, each pole piece 307 has a length similar to the length of the center lamination stack 305. Each pole piece 307 can be coupled with two guides 111A and 111B that also have a similar length. In other configurations, the 111A and 111B pins can be shorter and more 111A and 111B pins can be used to occupy the length of the 307 pole piece to which they are attached.In even other forms, the 111A and 111B markers can have a shape other than the rectangular prism illustrated in Figure 5B. Continuing with reference to Figure 5B, each pole piece 307 may comprise an installation groove 309 for securing the pole piece 307 to the balance ring 313. In one embodiment, the installation groove 309 runs the entire length of the pole piece 307. In another embodiment, the installation groove 309 may terminate at the midpoint of the pole piece 307. In embodiments in which the rotor contains two balance rings, one at each end of the center lamination stack 305, the pole pieces 307 may have an installation groove 309 extending the length of the pole pieces 307, or the pole pieces 307 may have an installation groove 309 at each end of the pole piece 307, each installation groove 309 terminating within the length of the pole piece 307.As described herein, in some embodiments, the pole pieces 307, the manes 111A and 111B, and the center lamination stack 305 can be installed together during manufacturing, so that the unit has no installation slots 309 or location studs 507. Figure 6 is half of the cross-section of a rotor, according to this disclosure. Regarding the components, starting from the stem 107 and moving outward, Figure 6 shows the center lamination stack 305, the magnet 111A coupled with the pole piece 307, and the locating pin 507 interlocked with the mounting groove 309 in the pole piece 307. The entire unit is mounted on the balance ring 313. This illustration shows how the locating pin 507 can be integrated into the balance ring 313 and only projects from the surface of the balance ring 313 that makes contact with the rotor unit. Figure 7 compares the torque generation of the disclosed wrapped motor against a conventional permanent magnet motor. The solid line 701 tracks the amount of torque generated at various speeds by the disclosed wrapped motor. The dashed line 703 represents the torque generated at the same speeds by a conventional permanent magnet motor. As shown, the wrapped motor can produce more torque than the conventional motor at the same speeds. The wrapped motor may have a higher peak torque because the elimination of ribs and bridges allows for greater fundamental flux. The wrapped motor can also produce more power than a conventional motor at the same speeds. The higher fundamental flux for the slot harmonic ratios results in greater motor efficiency at high speeds, both at low and high torque. Furthermore, the carbon-wrapped motor design can reduce or eliminate leakage, allowing for better use of reversing current and resulting in a peak power increase of up to 25% or more. At high speeds, the wrapped motor can generate more power compared to a conventional motor without increasing the use of permanent magnets. The foregoing disclosure is not intended to limit the present disclosure to the precise forms or particular fields of use disclosed. As such, it is contemplated that various alternative embodiments and / or modifications to the present description, whether explicitly described or implied herein, are possible in light of the disclosure. Having thus described the embodiments of the present disclosure, a person skilled in the art will recognize that changes in form and detail may be made without departing from the scope of the present disclosure. Therefore, the present disclosure is limited only by the claims. In the preceding specification, the disclosure has been described with reference to specific embodiments. However, as a person skilled in the art will appreciate, several embodiments described herein may be modified or implemented in various other ways without departing from the spirit and scope of the description. Accordingly, this description should be considered illustrative and is intended to teach those skilled in the art how to manufacture and use various embodiments of the motor unit. It should be understood that the embodiments shown and described herein are to be taken as representative embodiments. Equivalent elements, materials, processes, or steps may be substituted for those illustrated and described representatively in this document.Furthermore, certain features of the disclosure may be used independently of the use of other features, all of which will be evident to a person skilled in the art after benefiting from this description of the disclosure. Expressions such as "includes," "comprises," "incorporates," "consists of," "has," and "is" used to describe and claim this disclosure are intended to be interpreted non-exclusively, that is, allowing for articles, components, or elements not explicitly described to also be present. Reference to the singular should also be interpreted in relation to the plural. Furthermore, several modalities described in this document should be taken in an illustrative and explanatory sense and should in no way be interpreted as limiting the present description. All joint references (e.g., attached, fixed, coupled, connected, and the like) are used only to assist the reader in understanding this disclosure and cannot create limitations, particularly regarding the position, orientation, or use of the systems and / or methods described herein. Therefore, references to attachment, if any, should be interpreted broadly. Moreover, such references to attachment do not necessarily imply that two items are directly connected and in a fixed relationship to one another. Furthermore, all numerical terms, such as, but not limited to, first, second, third, primary, secondary, principal, or any other ordinary and / or numerical term, should also be taken only as identifiers, to assist the reader in understanding the various elements, modalities, variations, and / or modifications of this disclosure, and may not create any limitation, particularly as to the order or preference, of any element, modality, variation, and / or modification relating to, or on, another element, modality, variation, and / or modification. It should also be noted that one or more of the elements depicted in the drawings / figures may also be implemented in a more separate or integrated manner, or even eliminated or rendered unusable in certain cases, as appropriate for a particular application. Furthermore, any signal shading in the drawings / figures should be considered illustrative only and not limiting, unless otherwise specified.

Claims

1. An electric motor comprising: a stator configured to generate a magnetic field and accept a rotor in a central opening; and a rotor of such size as to fit within the central opening, wherein the rotor comprises: a plurality of pole pieces; a central lamination stack comprising a plurality of slots; and a plurality of magnets, wherein the rotor is wrapped in a multi-layered winding of a fiber material taut on its outer circumference; wherein the plurality of magnets are not entirely contained by the rotor, and wherein the plurality of magnets and the plurality of pole pieces are located within the plurality of slots.

2. The electric motor according to claim 1, further characterized in that the rotor comprises a centrally located stem with a first end and a second end, wherein the first end of the stem comprises a radially projecting disc.

3. The electric motor according to claim 2, further characterized in that the circumference of the disc is interrupted by a plurality of flat edges.

4. The electric motor according to claim 2, further characterized in that it additionally comprises a balance ring adjacent to the first end of the stem and a plurality of locating pins in the balance ring.

5. The electric motor according to claim 4, further characterized in that the locating pins are integrated in a circular pattern concentric with the balance ring.

6. The electric motor according to claim 1, further characterized in that the plurality of magnets is coupled to the plurality of pole pieces so that each pole piece is coupled with at least two magnets.

7. The electric motor according to claim 6, further characterized in that each of the pole pieces is locked with the plurality of slots in a central lamination stack so that the plurality of handles is oriented between an inner edge of the pole piece and an outer edge of the central lamination stack.

8. The electric motor according to claim 7, further characterized in that it additionally comprises a plurality of locating pins that run through the rotor via installation slots in an edge of each pole piece. frnocnn / eznz / q / uli 9. The electric motor according to claim 1, further characterized in that the fiber material comprises a carbon fiber material.

10. The electric motor according to claim 1, further characterized in that there is an empty space between one end of each of the plurality of handles and the multi-layered winding of the fiber material.

11. A method for assembling a rotor for an electric motor, comprising: inserting magnetic parts into slots on an outer circumference of a rotor attachment; positioning the magnetic parts with locating pins in the rotor attachment; tensioning non-metallic fibers in a filament winding apparatus; and winding the non-metallic fibers under tension around the rotor to hold the magnetic parts in position in the rotor attachment.

12. The method according to claim 11, for tensioning non-metallic fibers, further characterized in that it additionally comprises securing the filament winding equipment to a plurality of flat edges along a circumference of a disc at one end of the rotor attachment.

13. The method according to claim 11, further characterized in that the positioning of the magnetic parts with locating pins comprises securing the aligned magnetic parts against a surface of the rotor attachment.

14. A method for assembling a rotor for an electric motor, comprising: inserting magnetic pieces into slots in an outer circumference of a lamination stack; winding non-metallic fibers under tension around the rotor to hold the magnetic pieces in position in the slots.

15. The method according to claim 14, further characterized in that it additionally comprises locking the magnetic parts with locating pins into a rotor fitting.

16. The method according to claim 14, further characterized in that it additionally comprises installing the magnetic pieces in the rolling mill.

17. The method according to claim 14, for winding non-metallic fibers, further characterized in that it additionally comprises: Securing the filament winding equipment to a plurality of flat edges along a circumference of a disc at one end of a rotor attachment; and tensioning the non-metallic fibers in a filament winding equipment.

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