Power tool including a flux-enhanced motor

Abstract

The power tool of the present invention includes a battery pack interface configured to receive a removable and rechargeable battery pack and a motor. The motor includes a stator and a rotor, the stator including a plurality of stator teeth configured to receive a plurality of stator coils. The rotor includes a plurality of slots configured in a spoke-type configuration, each of the plurality of slots including a magnet receiving portion configured to receive one or more magnets. The rotor includes a direct axis inductance and an orthogonal axis inductance. The direct axis inductance of the rotor is greater than the orthogonal axis inductance of the rotor, and the direct axis current of the motor is positive during operation of the motor.

Description

[0001] Related Applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 588,370, filed on October 6, 2023, the entire contents of which are incorporated herein by reference into this application. Technical Field

[0002] The present invention relates to electric tools. Summary of the invention

[0003] Embodiments described herein relate to a power tool including a flux intensifying motor.

[0004] The power tool of the present invention includes a battery pack interface configured to receive a removable and rechargeable battery pack and a motor. The motor includes a stator and a rotor, the stator including a plurality of stator teeth configured to receive a plurality of stator coils. The rotor includes a plurality of slots configured in a spoke-type configuration, each of the plurality of slots including a magnet receiving portion configured to receive one or more magnets. The rotor includes a direct axis inductance and an orthogonal axis inductance. The direct axis inductance of the rotor is greater than the orthogonal axis inductance of the rotor, and the direct axis current of the motor is positive during operation of the motor.

[0005] In some aspects, each magnet receiving portion includes a centrally located center rib that divides the magnet receiving portion into a first section and a second section.

[0006] In some aspects, the first section is configured to receive a first magnet and the second section is configured to receive a second magnet.

[0007] In some aspects, the rotor includes a total of 8 magnets.

[0008] In some aspects, the rotor includes a total of 4 magnets.

[0009] In some aspects, each of the plurality of slots includes an open air gap at an outer circumferential surface of the rotor.

[0010] In some aspects, the rotor includes a plurality of air gaps positioned between adjacent slots of the plurality of slots.

[0011] In some aspects, the rotor comprises a volume less than 3000 cubic millimeters ("mm 3 ”) magnet.

[0012] In some aspects, the rotor comprises a volume less than 1500 cubic millimeters ("mm 3 ”) magnet.

[0013] The power tool of the present invention includes a battery pack interface configured to receive a removable and rechargeable battery pack and a motor. The motor includes a stator and a rotor, the stator including a plurality of stator teeth configured to receive a plurality of stator coils. The rotor includes a plurality of slots positioned perpendicular to a radial axis of the rotor, each of the plurality of slots including a magnet receiving portion configured to receive one or more magnets. The rotor includes a direct axis inductance and an orthogonal axis inductance. The direct axis inductance of the rotor is greater than the orthogonal axis inductance of the rotor, and the direct axis current of the motor is positive during operation of the motor.

[0014] In some aspects, each magnet receiving portion includes a centrally located center rib that divides the magnet receiving portion into a first section and a second section.

[0015] In some aspects, the first section is configured to receive a first magnet and the second section is configured to receive a second magnet.

[0016] In some aspects, the rotor includes a total of 8 magnets.

[0017] In some aspects, the rotor comprises a volume less than 3000 cubic millimeters ("mm 3 ”) magnet.

[0018] In some aspects, the rotor comprises a volume less than 2500 cubic millimeters ("mm 3 ”) magnet.

[0019] In some aspects, the rotor includes a plurality of air gaps positioned on an outer circumferential surface of the rotor.

[0020] In some aspects, the plurality of air gaps are funnel-shaped, and each of the plurality of air gaps is located between adjacent grooves of the plurality of grooves.

[0021] The power tool of the present invention includes a battery pack interface configured to receive a removable and rechargeable battery pack and a motor. The motor includes a stator and a rotor, the stator including a plurality of stator teeth configured to receive a plurality of stator coils. The rotor includes a plurality of slots configured in pairs to form a V-shaped configuration, each of the plurality of slots including a magnet receiving portion configured to receive one or more magnets, and each pair of the plurality of slots includes a centrally located center rib positioned between a first slot of the pair and a second slot of the pair. The rotor includes a direct axis inductance and an orthogonal axis inductance. The direct axis inductance of the rotor is greater than the orthogonal axis inductance of the rotor, and the direct axis current of the motor is positive during operation of the motor.

[0022] In some aspects, the rotor comprises a volume less than 3000 cubic millimeters ("mm 3 ”) magnet.

[0023] In some aspects, the rotor comprises a volume less than 1500 cubic millimeters ("mm 3 ”) magnet.

[0024] Before explaining any specific embodiment in detail, it should be understood that the specific embodiment is not limited to the application in the configuration details and component arrangements described in the following description or shown in the accompanying drawings. The specific embodiments can be implemented or realized in various ways. In addition, it should be understood that the words and terms used in this application are for illustrative purposes and should not be regarded as limiting. The use of "including", "comprising", "having" and their variations means that both the items listed thereafter and their equivalents and additional items are covered. Unless otherwise specified or limited, the terms "install", "connect", "support" and "couple" and their variations are used in a broad sense, covering both direct installation, connection, support and coupling, and indirect installation, connection, support and coupling.

[0025] The articles "a," "an," and "the" should not be construed as meaning "one" or "only one," unless the context clearly indicates otherwise. Instead, these articles should be construed as meaning "at least one" or "one or more than one." Similarly, when the term "the" or "said" is used to refer to a noun previously introduced by the indefinite article "a" or "an," "the" or "said" means "at least one" or "one or more than one," unless the context clearly indicates otherwise.

[0026] In addition, it should be understood that a specific embodiment may include hardware, software, and electronic components or modules, and for the purpose of discussion, these hardware, software, and electronic components or modules may be shown and described as if most of the components are implemented only in hardware. However, based on the reading of the specific embodiments of the present application, a person of ordinary skill in the art will recognize that in at least one specific embodiment, the electronic-based aspects can be implemented in software (e.g., stored on a non-transitory computer-readable medium), and the software can be executed by one or more processing units such as microprocessors and / or application-specific integrated circuits ("ASICs"). Therefore, it should be noted that a plurality of hardware- and software-based devices and a plurality of different structural components can be used to implement specific embodiments. For example, the "server", "computing device", "controller", and "processor" described in this specification may include one or more processing units, one or more computer-readable medium modules, one or more input / output interfaces, and various connectors (e.g., system buses) connecting these components.

[0027] For relative terms used in connection with quantities or conditions, such as "about", "approximately", "substantially", etc., those of ordinary skill in the art will understand that the values ​​are included, and the meaning of the terms is determined by the context (for example, the terms include at least the degree of error associated with the precision of the measurement, the tolerance associated with the specific value [for example, manufacturing, assembly, use tolerance, etc.], etc.). Such terms should also be considered to disclose the range defined by the absolute values ​​of the two endpoints. For example, the expression "from about 2 to about 4" also discloses the range of "from 2 to 4". Relative terms can refer to positive and negative percentages (for example, 1%, 5%, 10%) of the indicated value.

[0028] It should be understood that although some drawings show hardware and software located in a particular device, these depictions are for illustrative purposes only. The functions performed by a component described in this application can be performed in a distributed manner by multiple components. Similarly, the functions performed by multiple components can be combined and performed by a single component. In some specific embodiments, the components shown can be combined or divided into separate software, firmware and / or hardware. For example, logic and processing can be distributed between multiple electronic processors, rather than being located in a single electronic processor and performed by a single electronic processor. Regardless of how they are combined or divided, hardware components and software components can be located in the same computing device, or can be distributed between different computing devices connected by one or more than one network or other suitable communication links. Similarly, the components that perform specific functions can also perform additional functions not described in this application. For example, a device or structure that is "configured" in a certain way is configured at least in this way, but can also be configured in a way that is not explicitly listed.

[0029] Accordingly, in a claim, if an apparatus, method or system is described as, for example, comprising a controller, a control unit, an electronic processor, a computing device, a logic element, a module, a memory module, a communication channel or network, or other elements configured in some manner to, for example, perform multiple functions, this claim or an element of the claim should be interpreted as indicating one or more of such elements, such an element, i.e., any one of the one or more elements is configured as described in the claim to, for example, implement any one or more of the listed multiple functions, so that the one or more elements together as a group perform multiple functions.

[0030] Other aspects of the invention will become apparent from a careful reading of the detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A perspective view of a power tool according to some embodiments is shown.

[0032] Figure 2According to some embodiments, Figure 1 A block diagram of the control system of the power tool is shown.

[0033] Figure 3 According to some embodiments, Figure 1 Battery pack for use with the power tool shown.

[0034] Figure 4 According to some embodiments, Figure 3 A block diagram of the control system of the battery pack is shown.

[0035] Figure 5 A motor according to some embodiments is shown.

[0036] Figure 5A A motor according to some embodiments is shown.

[0037] Figure 5B A motor according to some embodiments is shown.

[0038] Figure 5C A motor according to some embodiments is shown.

[0039] Figure 6 A motor according to some embodiments is shown.

[0040] Figure 7 A motor according to some embodiments is shown.

[0041] Figure 8 A motor according to some embodiments is shown.

[0042] Fig. 8A A motor according to some embodiments is shown.

[0043] Fig. 9 A motor according to some embodiments is shown.

[0044] Fig.9A A motor according to some embodiments is shown.

[0045] Fig.10 A motor according to some embodiments is shown.

[0046] Fig.11 A motor according to some embodiments is shown.

[0047] Fig.12 A motor according to some embodiments is shown.

[0048] Fig. 12A A motor according to some embodiments is shown.

[0049] Fig. 12BA motor according to some embodiments is shown.

[0050] Fig. 12C A motor according to some embodiments is shown.

[0051] Fig.12D A motor according to some embodiments is shown.

[0052] Fig.12E A motor according to some embodiments is shown.

[0053] Fig.13 A motor according to some embodiments is shown.

[0054] Fig.14 A motor according to some embodiments is shown.

[0055] Fig.15 A motor according to some embodiments is shown.

[0056] Fig.16 A motor according to some embodiments is shown.

[0057] Fig.17 A motor according to some embodiments is shown.

[0058] Fig.18 A motor according to some embodiments is shown.

[0059] Fig.19 A motor according to some embodiments is shown.

[0060] Fig. 20 A motor according to some embodiments is shown.

[0061] Fig.21 A motor according to some embodiments is shown.

[0062] Fig. 22 A motor according to some embodiments is shown.

[0063] Fig.23 A motor according to some embodiments is shown.

[0064] Fig.24 is a graph showing performance characteristics of various motors according to some embodiments.

[0065] Fig.25 is a graph showing performance characteristics of various motors according to some embodiments.

[0066] Fig.26The relationship between direct axis current and quadrature axis current is shown according to some embodiments.

[0067] Fig. 27 The relationship between direct axis current and quadrature axis current is shown according to some embodiments.

[0068] Fig.28 The relationship between direct axis current and quadrature axis current is shown according to some embodiments.

[0069] Fig.29 The relationship between direct axis current and quadrature axis current is shown according to some embodiments. DETAILED DESCRIPTION

[0070] Figure 1 A power tool 100 including a motor, such as a memory motor, is shown. The power tool 100 is, for example, a hammer drill including a housing 102. Although Figure 1 A hammer drill is shown, but in some embodiments, the components described herein are integrated into other types of power tools, such as drill drivers, impact drivers, impact wrenches, angle grinders, circular saws, reciprocating saws, plate compactors, core drills, trimmers, leaf blowers, vacuum cleaners, or other applicable applications where field weakening may be used to operate the motor. The housing 102 includes a handle portion 104 and a motor housing portion 106. The power tool 100 further includes an output driver 108 (shown as a chuck), a trigger 110, and a battery pack interface 112. The battery pack interface 112 is configured to mechanically and electrically connect to or receive a power tool battery pack. In a memory motor power tool such as the power tool 100, a switching element is selectively enabled and disabled by a control signal from a controller to selectively apply power from a power source (e.g., a battery pack) to drive a memory motor.

[0071] Figure 2A control system 200 for a power tool 100 is shown. The control system 200 includes a controller 202. The controller 202 is electrically and / or communicatively connected to various modules or components of the power tool 100. For example, the illustrated controller 202 is electrically connected to a motor 204, a battery pack interface 206, a trigger switch 208 (connected to a trigger 210), one or more sensors or sensing circuits 212, one or more indicators 214, a user input module 216, a power input module 218, an inverter bridge or FET switch module 220 (including a plurality of switching FETs), and a gate driver 224 for driving the FET switch module 220. In some embodiments, the motor 204 is a memory motor. The controller 202 includes a combination of hardware and software that can be used, among other things, to control the operation of the power tool 100, monitor the operation of the power tool 100, activate one or more indicators 214 (e.g., LEDs), and the like.

[0072] The controller 202 includes a plurality of electrical and electronic components that provide power, operational control, and protection to the components and modules within the controller 202 and / or the power tool 100. For example, the controller 202 includes, among other things, a processing unit 226 (e.g., a microprocessor, a microcontroller, an electronic controller, an electronic processor, or another suitable programmable device), a memory 228, an input unit 230, and an output unit 232. The processing unit 226 includes, among other things, a control unit 234, an arithmetic logic unit ("ALU") 236, and a plurality of registers 238, and is implemented using known computer architectures, such as a modified Harvard architecture, a von Neumann architecture, and the like. The processing unit 226, the memory 228, the input unit 230, and the output unit 232, as well as the various modules or circuits connected to the controller 202, are connected via one or more control and / or data buses (e.g., a common bus 240). For purposes of illustration, the common bus 240 is described in detail below. Figure 2 The control and / or data bus is generally shown in FIG. In view of the inventions described herein, the use of one or more control and / or data buses for interconnection and communication between various modules, circuits and components will be known to those skilled in the art.

[0073] The memory 228 is a non-transitory computer-readable medium and includes, for example, a program storage area and a data storage area. The program storage area and the data storage area may include a combination of different types of memory, such as read-only memory ("ROM"), random access memory ("RAM") (e.g., DRAM, SDRAM, etc.), EEPROM, flash memory, hard disk, SD card, or other suitable magnetic, optical, physical or electronic memory devices. The processing unit 226 is connected to the memory 228 and executes software instructions that can be stored in the RAM of the memory 228 (e.g., during execution), the ROM of the memory 235 (e.g., on a substantially permanent basis), or another non-transitory computer-readable medium such as another memory or disk. The software included in the implementation of the power tool 100 can be stored in the memory 228 of the controller 202. The software includes, for example, firmware, one or more applications, program data, filters, rules, one or more program modules, and other executable instructions. The controller 202 is configured to retrieve and execute instructions related to the control process and method described in the present invention from the memory 228, etc. In other constructions, the controller 202 includes additional, fewer, or different components.

[0074] The battery pack interface 206 includes a combination of mechanical components (e.g., rails, grooves, latches, etc.) and electrical components (e.g., one or more terminals) that are configured and operable to interface with (e.g., mechanically, electrically, and communicatively connect to) a battery pack. For example, from the battery pack 300 (see Figure 3 ) Power provided to the power tool 100 is provided to a power input module 218 through the battery pack interface 206. The power input module 218 is a combination of active and passive components to condition or control the power received from the battery pack 300 before the power is provided to the controller 202. The battery pack interface 206 also provides power to the FET switch module 220, which is switched by switches FET to selectively provide power to the motor 204. The battery pack interface 206 also includes, for example, a communication line 242 for providing a communication line or link between the controller 202 and the battery pack 300.

[0075] The sensor 212 includes one or more current sensors, one or more speed sensors, one or more Hall effect sensors, one or more temperature sensors, etc. The indicator 214 includes, for example, one or more light emitting diodes ("LEDs"). The indicator 214 can be configured to display the condition of the power tool 100 or information associated therewith. For example, the indicator 214 is configured to indicate the measured electrical characteristics of the power tool 100, the status of the power tool, the status of the motor 204, etc. The user input module 216 is operably coupled to the controller 202 to, for example, select a forward operating mode or a reverse operating mode, a torque and / or speed setting of the power tool 100 (e.g., using a torque and / or speed switch), etc. In some specific embodiments, the user input module 216 includes a combination of digital and analog input or output devices required to achieve the desired operating level of the power tool 100, such as one or more knobs, one or more dials, one or more switches, one or more buttons, etc.

[0076] Figure 3 A battery pack 300 is shown. The battery pack 300 includes a housing 302 and an interface portion 304 for connecting the battery pack 300 to a power tool such as the power tool 100.

[0077] Figure 4 4 is a diagram showing a control system for a battery pack 300. The control system includes a controller 400. The controller 400 is electrically and / or communicatively connected to various modules or components of the battery pack 300. For example, the illustrated controller 400 is connected to one or more battery cells 402 and an interface 404 (e.g., Figure 3 Controller 400 is also connected to one or more voltage sensors or voltage sensing circuits 406, one or more current sensors or current sensing circuits 408, and one or more temperature sensors or temperature sensing circuits 410. Controller 400 includes a combination of hardware and software that can be used to control the operation of battery pack 300, monitor the operation of battery pack 300, enable or disable charging of battery pack 300, enable or disable discharging of battery pack 300, etc.

[0078] The controller 400 includes a plurality of electrical and electronic components that provide power, operational control, and protection to the components and modules within the controller 400 and / or the battery pack 300. For example, the controller 400 includes, among other things, a processing unit 412 (e.g., a microprocessor, a microcontroller, an electronic processor, an electronic controller, or another suitable programmable device), a memory 414, an input unit 416, and an output unit 418. The processing unit 412 includes, among other things, a control unit 420, an ALU 422, and a plurality of registers 424, and is implemented using known computer architectures, such as a modified Harvard architecture, a von Neumann architecture, and the like. The processing unit 412, the memory 414, the input unit 416, and the output unit 418, as well as the various modules or circuits connected to the controller 400, are connected via one or more control and / or data buses (e.g., a common bus 426). For purposes of illustration, the common bus 426 is described in detail below. Figure 4 The control and / or data bus is generally shown in FIG. In view of the inventions described herein, the use of one or more control and / or data buses for interconnection and communication between various modules, circuits and components will be known to those skilled in the art.

[0079] The memory 414 is a non-temporary computer-readable medium and includes, for example, a program storage area and a data storage area. The program storage area and the data storage area may include a combination of different types of memory, such as ROM, RAM (e.g., DRAM, SDRAM, etc.), EEPROM, flash memory, hard disk, SD card or other suitable magnetic, optical, physical or electronic storage devices. The processing unit 412 is connected to the memory 414 and executes software instructions that can be stored in the RAM of the memory 414 (e.g., during execution), the ROM of the memory 414 (e.g., on a substantially permanent basis) or another non-temporary computer-readable medium such as another memory or disk. The software included in the implementation of the battery pack 300 can be stored in the memory 414 of the controller 400. The software includes, for example, firmware, one or more than one application, program data, filters, rules, one or more than one program modules and other executable instructions. The controller 400 is configured to retrieve and execute instructions related to the control process and method described in the present invention from the memory 414. In other configurations, the controller 400 includes additional, fewer or different components.

[0080] The interface 404 includes a combination of mechanical components (e.g., rails, grooves, latches, etc.) and electrical components (e.g., one or more terminals) that are configured and operable to interface (e.g., mechanically, electrically, and communicatively connect) the battery pack 300 with another device. For example, the interface 404 is configured to be communicatively connected to the controller 400 via the communication line 428.

[0081] A plurality of motors that may be used in the power tool 100 are described below as separate embodiments of the motor 204. The motor is, for example, a flux-enhanced motor. As will be described in more detail below, existing motors have a direct axis or d-axis, and the current is negative. When field weakening is used, the negative d-axis current increases, which results in a large amount of current being consumed. The flux-enhanced motor may be manufactured with controlled rotor geometry (e.g., air gaps, notches, cutouts, spoke-type configurations, V-shaped configurations, etc.) and magnets (e.g., thinner magnets, center ribs, multiple small magnets, etc.) to change the d-axis current from a negative value to a positive value by increasing the d-axis inductance. When the d-axis inductance of the motor is greater than the orthogonal or q-axis inductance, the motor is classified as a flux-enhanced motor. Several embodiments of flux-enhanced motors are described in the present invention in conjunction with various techniques for implementing flux-enhanced motors.

[0082] Figure 5 A motor 500 according to some embodiments is shown. In some embodiments, the motor 500 is, for example, a flux-enhanced motor. The motor 500 includes a stator 501 and a rotor 502. The rotor 502 includes a plurality of permanent magnets 504 (and in the illustrated embodiment, 4 magnets 504) positioned in a rectangular configuration and more specifically in a square configuration around a longitudinal axis 512 of the motor 500 (i.e., perpendicular to a radial axis of the motor 500). The magnets 504 are positioned in corresponding magnet cavities 508 aligned parallel to the longitudinal axis 512 of the motor 500. The rotor 1602 of the motor 1600 (see Figure 5B ), the rotor 502 of the motor 500 includes a smaller amount of magnetic material than the motor 1600. The magnet 504 includes a magnet width 532 and a magnet thickness 536. Each magnet cavity 508 includes a cavity width 540. In the illustrated embodiment, the magnet width 532 is less than the width of the magnet 1604 of the motor 1600 ( Figure 5B ), which allows motor 500 to include less total magnet material than motor 1600. In some embodiments, the ratio of magnet width 532 to cavity width 540 (i.e., magnet width 532 divided by cavity width 540) can be between 0.5 and 0.99, between 0.5 and 0.95, between 0.6 and 0.9, between 0.7 and 0.9, between 0.7 and 0.8, between 0.8 and 0.9, or between 0.9 and 0.95. Motor 500 includes a d-axis 516 and a q-axis 520.

[0083] Figure 5AA rotor 1500 of an electric motor is shown. The rotor 1500 includes a plurality (and in the illustrated embodiment, four) of recesses 1528 positioned about a central recess 1526. The recess 1528 may be oblong. The central recess 1526 includes a plurality (and in the illustrated embodiment, five) of further recesses positioned equidistantly about the central recess 524 to increase the cross-sectional area of ​​the central recess 1524 beyond the area of ​​the annulus defined by the curved outer wall 1526 of the central recess 1524. The magnet cavity 1508 of the rotor 1500 includes a cavity thickness 1536, which may be approximately equal to the magnet thickness of the permanent magnet mounted within the cavity 1508. The cavity thickness 1536 may be, for example, between 1.0 mm and 3.0 mm, between 2.0 mm and 2.5 mm, between 2.1 mm and 2.2 mm, or about 2.15 mm. The volume of the magnet contained within the rotor 1500 may be, for example, between 2500 mm 3 and 3500 mm 3 Between, 2800 mm 3 and 3200 mm 3 Between, about 3000 mm 3 or about 3013 mm 3 .

[0084] Figure 5B An interior permanent magnet (IPM) motor 1600 is shown according to some embodiments. The motor 1600 includes a stator 1601 (in the embodiment shown, an outer stator 1601) and a rotor 1602 (in the embodiment shown, an outer stator 1602). The rotor 1602 includes four permanent magnets 1604 positioned in a square configuration. The permanent magnets 1604 are positioned within respective magnet cavities 1608 aligned parallel to a longitudinal axis 1612 of the motor 1600. The motor 1600 includes a d-axis 1616 (one of which is shown in FIG. 1 ). Figure 5B ) and q axis 1620 (one of which is shown in Figure 5B The motor 1600 includes a d-axis inductance Ld along the d-axis 1616. 1600 and the q-axis inductance Lq along the q-axis 1620 1600 The rotor 1602 includes a central bore 162 centered on a longitudinal axis 1612. The components of the motor 1600 are arranged such that the q-axis inductance Lq 1600 Greater than d-axis inductance Ld 1600 .

[0085] Figure 5CAn IPM motor 1700 is shown that is similar to motor 1600. Motor 1700 includes a permanent magnet 1704, a central hole 1724, and a plurality (and in the embodiment shown, four) of holes 1728 surrounding the central hole 1724. The holes 1728 may be circular and may be positioned between the respective magnets 1704 and the central hole 1724.

[0086] Figure 6 A motor 600 according to some embodiments is shown. In some embodiments, the motor 600 is, for example, a flux-enhanced motor. The motor 600 is configured as a permanent magnet synchronous reluctance motor (PMaSynRM). The motor 600 includes an outer stator 601 and an inner rotor 602. The rotor 602 includes a plurality of (and in the embodiment shown, 8) permanent magnets 604. The magnets 604 are positioned in a double-layer rectangular configuration, and more specifically in a double-layer square configuration (i.e., perpendicular to the radial axis of the motor 600). The magnets 604 include four relatively wide magnets 605 and four relatively narrow magnets 606. Each wider magnet 605 is positioned radially inward from a corresponding one of the narrower magnets 606. Therefore, the magnets 604 are arranged in pairs, each pair including an outer narrower magnet 606 and an inner wider magnet 605 and each pair is positioned at a 90-degree angle relative to the adjacent pairs. Each magnet 605 is positioned in an inner magnet cavity 608. Each inner magnet cavity 608 includes a first end 609 and an opposite second end 610, both of which are open to the exterior of the rotor 602. Each magnet 606 is positioned in an outer magnet cavity 612. Each outer magnet cavity 612 includes a first end 613 and an opposite second end 614, both of which are open to the exterior of the rotor 602. An air gap may be positioned at each end of the magnetic cavity.

[0087] Figure 7 A motor 700 is shown according to some embodiments. In some embodiments, the motor 700 is, for example, a flux-enhanced motor. The motor 700 includes an outer stator 701 and an inner rotor 702. The rotor 702 of the motor 700 includes permanent magnets 704, and the permanent magnets 704 include a V-shaped configuration (e.g., the magnets 704 are separated by a center rib 744 and adjacent magnet pairs are configured in a V shape). The motor 700 includes a d-axis 716 and a q-axis 720, each of which has a line shown in FIG. Figure 7 The center rib 744 is positioned between the magnets 704 and at the end of the magnets 704 closest to the center hole 724 of the motor 700 .

[0088] Figure 8A motor 800 is shown according to some embodiments. In some embodiments, the motor 800 is, for example, a flux-enhanced motor. The motor 800 includes an outer stator 801 and an inner rotor 802. The rotor 802 of the motor 800 includes a permanent magnet 804 having a spoke-type configuration (e.g., the magnet 804 extends axially outward from the center of the motor 800). The magnet cavity 808 of the rotor 802 accommodates the magnet 804, and the magnet 804 includes a magnet thickness 836. The magnet thickness 836 can be approximately equal to the cavity thickness in some embodiments. In some embodiments, the thickness 836 can be between 1 mm and 3 mm, between 1.5 mm and 2.5 mm, about 2.0 mm, or about 1.8 mm. The volume of the magnet 804 within the rotor 802 can be between 1000 mm 3 and 2000 mm 3 Between 1200 mm 3 and 1800mm 3 Between 1400 mm 3 and 1600 mm 3 Between, about 1500 mm 3 or smaller, or about 1485 mm 3 .

[0089] Fig. 8A A motor 1800 is shown according to some embodiments. In some embodiments, the motor 1800 is, for example, a flux-enhanced motor. The motor 1800 includes an outer stator 1801 and an inner rotor 1802. The rotor 1802 includes a plurality of (and in the embodiment shown, 4) permanent magnets 1804. The magnets 1804 include a magnet thickness 1836, which in some embodiments can be approximately equal to the cavity thickness. In some embodiments, the thickness 1836 can be between 2.0 mm and 8.0 mm, between 3.0 mm and 7.0 mm, between 3.0 mm and 4.0 mm, between 4.0 mm and 5.0 mm, between 5.0 mm and 6.0 mm, between 6.0 mm and 7.0 mm, between 4.0 mm and 6.0 mm, between 4.5 mm and 5.5 mm, or about 5.0 mm. The magnet volume can be about 1500 mm 3 or about 1485 mm 3 In some embodiments, each of the plurality of magnet slots includes an open air gap at an outer circumferential surface of the rotor.

[0090] Fig. 9A motor 900 is shown according to some embodiments. In some embodiments, the motor 900 is, for example, a flux-enhanced motor. The motor 900 includes an outer stator 901 and an inner rotor 902. The rotor 902 of the motor 900 includes a plurality (and in the embodiment shown, eight) of permanent magnets 904 positioned within the rotor 902 in a rectangular configuration, and more specifically in a square configuration (i.e., perpendicular to the radial axis of the motor 900). The magnet cavities 908 of the rotor 902 house the magnets 904. The motor 900 is similar in some respects to Figure 5 902 of motor 900, except for certain obvious differences in the accompanying drawings. For example, rotor 902 includes a center rib 944 that separates adjacent magnets 904 positioned along the same side of the rectangle and / or square in which magnets 904 are arranged. At least because of the presence of center rib 944, rotor 902 of motor 900 includes a smaller amount of magnetic material (i.e., the cross-sectional area of ​​magnets 904 is reduced, and thus the volume of magnets 904 is reduced, which can save costs). Compared to rotor 502 of motor 500, center rib 944 of rotor 902 of motor 900 divides each magnet slot (i.e., magnet cavity) into two magnet slots or sections (e.g., magnet cavity 912). In some embodiments, center rib 944 is centrally located at each large magnet slot (e.g., Figure 5 The motor 900 includes a d-axis 916 and a q-axis 920, each of which has a line shown in FIG. Fig. 9 middle.

[0091] Fig.9A A rotor 1900 for an electric motor is shown. The rotor 1900 includes a plurality (and in the embodiment shown, eight) of magnet cavities 1908 arranged to be aligned with, for example, Fig. 9 The rotor 1900 is a rectangular (and more specifically a square) structure similar to the rotor 902 of FIG. The rotor 1900 includes a plurality of (and in the illustrated embodiment, 4) middle ribs 1944 positioned between adjacent cavities 1908. The middle ribs are positioned in the middle, approximately in the middle, and / or in the middle region of the respective sides of the rectangle and / or square defined by the cavity 1908. Each cavity 1908 includes a further recess 1909 (or air gap) positioned at the end of the cavity 1908 adjacent to another cavity 1908, the other cavity 1908 being positioned at an angle of about 90 degrees relative to the cavity 1908 where the further recess 1909 is located. The further recess 1909 is substantially facing inward (i.e., facing the outer circumference of the rotor 1900), rather than facing outward. The thickness of the cavity where the magnet is located can be, for example, between 1.0 mm and 3.0 mm, between 1.25 mm and 1.75 mm, or about 1.5 mm. The volume of the magnets contained in the rotor 1500 may be, for example, 1500 mm 3 and 2000 mm 3Between 1600 mm 3 and 1800 mm 3 Between, about 1750 mm 3 , or about 1761 mm 3 .

[0092] Fig.10 1 shows a motor 1000 according to some embodiments. In some embodiments, the motor 1000 is, for example, a flux-enhanced motor. The motor 1000 includes an outer stator 1001 and an inner rotor 1002. The motor 1000 is similar in some respects to Figure 6 600, except for certain obvious differences in the drawings. For example, the rotor 1002 of the motor 1000 includes a plurality (and 16 in the illustrated embodiment) of permanent magnets 1004, which are positioned within the rotor 1002 in a double-layer rectangular configuration and more specifically in a double-layer square configuration in the illustrated embodiment (i.e., perpendicular to the radial axis of the motor 1000). The magnets 1004 include 8 relatively wide magnets 1005 and 8 relatively narrow magnets 1006. Each wider magnet 1005 is positioned radially inward from the corresponding narrower magnet 1006. Each magnet 1004 is positioned within a magnet cavity 1008. The motor 1000 is configured as a permanent magnet synchronous reluctance motor (PMaSynRM). The rotor 1002 of the motor 1000 also includes a plurality of center ribs 1044 that divide each cavity (i.e., each magnet slot) into two cavities 1008 (i.e., two magnet slots or sections). In some embodiments, the center rib 1044 is centrally located at the center of each large magnet slot. The center rib 1044 is located at the center, approximately the center, and / or in the middle area of ​​the corresponding side of the rectangle and / or square defined by the cavity 1008.

[0093] Fig.11 1 shows a motor 1100 according to some embodiments. In some embodiments, the motor 1100 is, for example, a flux-enhanced motor. The motor 1100 includes an outer stator 1101 and an inner rotor 1102. The motor 1100 is similar in some respects to Figure 8 The motor 800 is shown in the drawings except for certain obvious differences. The rotor 1102 of the motor 1100 includes eight permanent magnets 1104 having a spoke-type configuration (e.g., extending axially outward from the center of the motor) and positioned in a magnet cavity that is substantially completely occupied by the magnets 1104 in the illustrated embodiment. The rotor 1102 of the motor 1100 also includes eight permanent magnets 1104 having a spoke-type configuration (e.g., extending axially outward from the center of the motor) and positioned in a magnet cavity. The magnet cavity is substantially completely occupied by the magnets 1104 in the illustrated embodiment. Figure 8Each magnet slot of the motor 800 of the embodiment is divided into two magnet slots (i.e., magnet cavities or sections) by a middle rib 1144. In some embodiments, the middle rib 1144 is centrally located at the center of each large magnet slot. Each middle rib 1144 can be located in the middle of the spoke 1145, approximately in the middle of the spoke 1145, and / or in the approximately middle area of ​​the spoke 1145. Each spoke 1145 can be located at a 90 degree angle relative to an adjacent spoke 1145.

[0094] Fig.12 A motor 1200 according to some embodiments is shown. In some embodiments, the motor 1200 is, for example, a flux-enhanced motor. The motor 1200 includes an outer stator 1201 and an inner rotor 1202. The rotor 1202 includes a plurality of (and in the embodiment shown, four) permanent magnets 1204 arranged in a rectangular configuration in the rotor 1202 and more specifically in a square configuration in the embodiment shown (i.e., perpendicular to the radial axis of the motor 1200). The motor 1200 is similar in some respects to Figure 5 , 5B and 5C motors 500, 1600, 1700, except for certain obvious differences in the drawings. For example, the rotor 1202 of the motor 1200 includes a plurality of gaps 1248 or notches in the rotor lamination stack of the rotor 1202. The gaps 1248 represent, for example, areas where non-magnetic material has been removed, which results in an increase in magnetic flux. The gaps 1248 are funnel-shaped and each gap 1248 includes a V-shaped portion 1249 and a straight portion 1250 extending from the tip of the V-shaped portion 1249. The gaps 1248 (and correspondingly, the straight portions 1250) are aligned along the q-axis 1220 of the rotor 1202. The q-axis 1220 is positioned at a certain angle relative to the d-axis 1216. Each funnel-shaped gap 1248 is positioned at 90 degrees to an adjacent funnel-shaped gap 1248. Gap 1248 acts as a flux barrier along q-axis 1220 to reduce magnetic flux along q-axis 1220 relative to magnetic flux along d-axis 1216 .

[0095] Fig. 12A A rotor 2000 for use with an electric motor according to some embodiments is shown. In some embodiments, the rotor 2000 is, for example, a flux-enhanced rotor. The rotor 2000 is similar in some respects to Fig.121200 and includes a permanent magnet 2004 and a gap 2048. The magnet 2004 may include a magnet width 2032 and a magnet thickness 2036. The gap 1248 includes a V-shaped portion 2049 and a straight portion 2050 extending from the tip of the V-shaped portion 1249. In some embodiments, the straight portion 2050 has a length between zero and 10 times the thickness of the rotor lamination. The distance 2052 between the magnet 2004 and the gap 1248 (and more specifically the V-shaped portion 1249) can be changed according to the desired performance of the rotor 2000. The distance 2056 between two adjacent gaps 1248 is greater than the width 2032 of the magnet 2004 in some embodiments. The ratio of the distance 2052 between one of the magnets 2004 and an adjacent one of the gaps 1248 to the distance 2056 between two adjacent gaps 1248 can be between 0.01 and 0.15, between 0.01 and 0.10, between 0.02 and 0.09, between 0.03 and 0.08, between 0.03 and 0.07, between 0.04 and 0.08, between 0.05 and 0.08, between 0.06 and 0.08, or about 0.07. The ratio of the distance 2052 between one of the magnets 2004 and the adjacent one of the gaps 1248 to the width 2031 of the magnet 2004 can be between 0.01 and 0.15, between 0.02 and 0.12, between 0.03 and 0.10, between 0.04 and 0.08, about 0.08, between 0.05 and 0.08, between 0.05 and 0.07, about 0.06, between 0.01 and 0.05, between 0.01 and 0.04, between 0.01 and 0.03, or between 0.01 and 0.02. In some embodiments, the rotor laminations have a thickness of about 0.35 mm. In some embodiments, the distance 2052 is between zero and ten times the thickness of the rotor laminations (e.g., 0 mm to 3.5 mm). In some embodiments, the thickness of the magnet 2004 should not exceed 20 times the thickness of the air gap, which applies to all similarly shaped rotors described in the present invention. In some embodiments, the width of the magnet is between 1.0 mm and 2.0 mm or is, for example, 1.5 mm.

[0096] Fig. 12B A rotor 2100 for use with an electric motor according to some embodiments is shown. In some embodiments, the rotor 2100 is, for example, a flux-enhanced rotor. The rotor 2100 is similar in some respects to Fig.12 and 12A The rotor 2100 includes a gap 2148 which can be spaced relative to the rotor 1202, 2000 except for certain obvious differences in the drawings. Fig. 12AThe gap 2048 is modified so that the distance 2052 has been reduced to zero or approximately zero. The gap 2148 is a V-shaped gap 2148.

[0097] Fig. 12C A rotor 2200 for use with an electric motor according to some embodiments is shown. In some embodiments, the rotor 2200 is, for example, a flux-enhanced rotor. The rotor 2200 is similar in some respects to Fig.12 , 12A 12B, except for certain obvious differences in the drawings. The rotor 2200 includes a gap 2248 which can be relative to the Fig. 12A The gap 2048 is modified so that the gap 2248 is formed as a straight gap without the V-shaped portion 1249. In some embodiments, Fig. 12A The distance 2052 is equal to 10 times the thickness of the laminate.

[0098] Fig.12D A rotor 2300 for use with an electric motor according to some embodiments is shown. In some embodiments, the rotor 2300 is, for example, a flux-enhanced rotor. The rotor 2300 is similar in some respects to Fig.12 , 12A 12B and 12C, except for certain obvious differences in the drawings. The rotor 2300 includes a gap 2348, which can be relative to Fig. 12A The gap 2048 of the embodiment can be modified. For example, the gap 2348 may not include the straight portion 2050, but only include the V-shaped portion 2349. The V-shaped portion 2349 may include two adjacent sides 1253. The angle between the two adjacent sides 1253 may be about 90 degrees, between 80-100 degrees, between 70-110 degrees, or between 60-120 degrees in some embodiments. Fig. 12A The V-shaped portion 2049 may have similar dimensions in some embodiments. The size and shape of the V-shaped portion 2349 can be designed to determine the desired distance 2352 between the permanent magnet 2304 and the adjacent gap 2348. For example, the distance 2352 is (e.g., Fig. 12A The ratio of the width of magnet 2304 (measured in a similar manner to the width 2032) can be, for example, 0.01, between 0.01 and 0.05, between 0.02 and 0.07, between 0.03 and 0.10, between 0.04 and 0.15, between 0.05 and 0.20, about 0.10, or between 0.08 and 0.12.

[0099] Fig.12EA rotor 2400 for use with an electric motor according to some embodiments is shown. In some embodiments, the rotor 2400 is, for example, a flux-enhanced rotor. The rotor 2400 is similar in some respects to Fig.12 , 12A , 12B, 12C and 12D, except for certain obvious differences in the drawings. The rotor 2400 includes a gap 2448, which can be relative to Fig. 12A For example, the gap 2448 is modified relative to Fig. 12A The gap 2048 extends toward the longitudinal axis 2412 of the rotor 2400 (e.g., more than halfway along the axis 2412). The gap 2448 includes a V-shaped portion 2449 and an extension portion 2450. In some embodiments, the extension portion 2450 can be a straight portion 2450, or the extension portion 2450 can be inclined like the V-shaped portion 2449 but at a steeper slope than the V-shaped portion 2449. The V-shaped portion 2449 can be defined by a radial distance 2453, and the extension portion 240 can be defined by a radial distance 2454 relative to the longitudinal axis 2412. The distance ratio between distance 2453 and distance 2454 can be about 1.0, about 0.9, about 0.8, about 0.7, about 0.5, about 1.1, about 1.2, about 1.3, about 1.4, about 1.5, between 0.55 and 1.45, between 0.65 and 1.35, between 0.75 and 1.25, between 0.85 and 1.15, or between 0.95 and 1.05.

[0100] Fig.13A motor 1300 according to some embodiments is shown. In some embodiments, the motor 1300 is, for example, a flux-enhanced motor. The motor 1300 includes an outer stator 1301 and an inner rotor 1302. The rotor 1302 of the motor 1300 includes permanent magnets 1304 positioned in a spoke-type configuration (e.g., extending axially from a longitudinal axis 1312 of the motor 1300). The rotor 1302 of the motor 1300 includes a plurality of air gaps or gaps (e.g., removal of non-magnetic material) in the rotor lamination stack, which results in increased magnetic flux. More specifically, the rotor 1302 includes gaps formed as slits and gaps formed as arrow-shaped gaps 1364. The slits 1360 are positioned transversely to the magnets 1304, and the arrow-shaped gaps 1364 (and in the illustrated embodiment, there are 4 arrow-shaped gaps 1364) extend radially outward from the longitudinal axis 1312. Each arrow-shaped gap 1364 is positioned 90 degrees relative to an adjacent arrow-shaped gap 1364. The q-axis 1316 can be aligned along the magnet 1304 (i.e., in a radial direction from the longitudinal axis 1312). The d-axis 1320 can be positioned transverse to the q-axis 1320. Along the q-axis 1316, an external notch 1368 is provided at the outer circumference of the rotor 1302 to serve as a flux barrier along the q-axis. In some embodiments, each notch 1368 is defined by a circular segment spanning the outer circumference of the rotor 1302. The segment defining the notch 1368 may span, for example, about 5 degrees, about 10 degrees, about 15 degrees, about 20 degrees, about 25 degrees, about 30 degrees, about 35 degrees, about 40 degrees, about 45 degrees, about 50 degrees, about 55 degrees, about 60 degrees, about 65 degrees, about 70 degrees, about 75 degrees, about 80 degrees, about 85 degrees, about 90 degrees, between 15 and 75 degrees, between 30 and 60 degrees, or between 40 and 50 degrees.

[0101] Fig.14 A motor 1400 is shown according to some embodiments. In some embodiments, the motor 1400 is, for example, a flux-enhanced motor. The motor 1400 includes an outer stator 1401 and an inner rotor 1402. The rotor 1402 of the motor 1400 includes permanent magnets 1404 positioned in a spoke-type configuration. The motor 1400 is similar in some respects to Fig.131300, except for certain obvious differences in the drawings. The rotor 1402 of the motor 1400 includes a spoke-type structure for the rotor magnets (e.g., extending axially from the center of the motor). In the specific embodiment shown, the rotor 1402 of the motor 1400 includes a center rib 1444, which divides each magnet slot into two magnet slots, which allows the eight magnets 1404 to be positioned in corresponding magnet cavities or sections. In some embodiments, the center rib 1444 is centrally located at the center of each large magnet slot (i.e., divided into two magnet cavities of approximately equal size). The rotor of the motor 1400 also includes a plurality of air gaps or gaps 1446 in the rotor lamination stack (e.g., to remove non-magnetic material), which results in increased magnetic flux.

[0102] Fig.15 A rotor 2500 for use with an electric motor is shown according to some embodiments. In some embodiments, the rotor 2500 is, for example, a flux-enhanced rotor. The rotor 2500 includes a plurality of permanent magnets 2504. In the illustrated embodiment, eight magnets 2504 are arranged in pairs, each pair forming a V-shaped configuration relative to the center of the rotor 2500. Two layers of gaps or notches (i.e., flux barriers) are provided in the rotor, and more specifically, an outer flux barrier 2572 is radially disposed outwardly relative to an inner flux barrier 2576. The flux barriers 2572, 2576 may be formed as arcs, semicircles, parabolas, or other curved shapes that open outwardly relative to the center of the rotor 2500. In the illustrated embodiment, four sets of flux barriers 2572, 2576 are positioned at 90 degrees relative to each other. The center rib 2580 is positioned in the middle region (or in some embodiments, in the middle) of the flux barriers 2572, 2576.

[0103] Fig.16A motor 2600 according to some embodiments is shown. In some embodiments, the motor 2600 is, for example, a flux-enhanced motor. The motor 2600 includes an outer stator 2601 and an inner rotor 2602. The motor 2600 includes a plurality of permanent magnets 2604, and in the illustrated embodiment, includes 16 magnets 2604. The magnets 2604 are arranged in 8 pairs, each pair forming a V-shaped configuration. A plurality of gaps or notches serve as outer flux barriers 2672 and inner flux barriers 2676. Each flux barrier 2672, 2676 (as a gap or notch) is filled with air, thereby changing the flux in the motor. The outer flux barrier 2672 is thicker in the radial direction than the inner flux barrier 2676. The ratio of the thickness of the outer flux barrier 2672 to the thickness of the inner flux barrier 2676 may be about 2, about 2.5, about 3, about 4, about 4.5, about 5, about 5.5, about 6, between 2 and 6, or between 3 and 5. The flux barriers 2672, 2676 are open outward in the radial direction, and a pair of inner and outer flux barriers 2672, 2676 is provided for each V-shaped magnet pair 2604. As a flux-enhanced electric motor, the motor 2600 generates a magnetic flux Ld along the d-axis 2616 that is greater than the magnetic flux Lq along the q-axis 2620.

[0104] Fig.17 A motor 2700 according to some embodiments is shown. In some embodiments, the motor 2700 is, for example, a flux-enhanced motor. The motor 2700 includes an outer stator 2701 and an inner rotor 2702. The motor 2600 includes a plurality of permanent magnets 2704, and in the illustrated embodiment, includes 16 magnets 2704. The magnets 2704 are positioned in pairs, which causes each pair to form a curved shape (e.g., a parabola, a hyperbola, or other arc) that opens outward in a radial direction from the center of the rotor 2702. The notch 2768 is disposed at the outer circumference of the rotor 270202 and between the paired magnets 2704 in the circumferential direction, which causes the notch 2768 to be positioned along the q-axis 2720 (rather than the d-axis 2716) of the motor 2700 to reduce the q-axis flux and provide the flux-enhanced electric motor 2700 with a d-axis flux Ld that is greater than the q-axis flux Lq.

[0105] Fig.18 2800 having an outer stator 2801 and an inner rotor 2802, the d-axis magnetic flux path 2816 in the electric motor 2800, which in some embodiments can be a flux-enhanced electric motor. The electric motor 2800 can be similar in some aspects to Fig.15 and 16 The motors 2500 and 2600 are similar except for some obvious differences in the drawings. The stator 2801 includes windings 2803, while the rotor 2802 includes permanent magnets 2804 and flux barriers 2817, 2818.

[0106] Fig.19 Shows Fig.18 q-axis flux path 2820 in electric motor 2800. In some embodiments of motor 2800, the d-axis flux path is angularly offset relative to the q-axis flux path 2820 and may be angularly offset by 30 degrees, for example.

[0107] Fig. 20 and 21 The d-axis flux path 3016 and q-axis flux path 3020 of an electric motor 3000 having permanent magnets 3004 in a square configuration are shown, and the motor 3000 may be a flux-enhanced electric motor in some embodiments. The d-axis flux path 3016 and q-axis flux path 3020 may be circumferentially offset, and in some embodiments may be circumferentially offset by 30 degrees.

[0108] Fig. 22 and 23 The d-axis 3116 and q-axis 3120 are shown in an electric motor 3100 having an inner rotor 3102, which may be a flux-enhanced electric motor in some embodiments. The rotor 3102 includes permanent magnets 3104 arranged in pairs in a V-shaped configuration. In the specific embodiment shown, the d-axis 3116 passes through the radially inward point of the V-shaped configuration of a pair of magnets 3104, while the q-axis passes between adjacent V-shaped magnet pairs 3104. The d-axis and q-axis 3120 are circumferentially offset by an angle θ, which may be, for example, 30 degrees.

[0109] Fig.24 and 25 Graphs are shown of efficiency, output power in Watts, current in Amps, and speed in RPM as a function of torque in Nm. The graph line associated with a standard rotor (20Tx0.95mm PD; SI of 26.72 mΩ; battery pack voltage of 20.32 V) is indicated by reference numeral 3201. The graph line associated with a flux-enhanced motor adapted for field weakening performance (20Tx0.95mm PD; 26.29 mΩ; battery pack voltage of 20.32 V) is indicated by reference numeral 3202.

[0110] Fig.26 A current graph showing negative d-axis current 3301 , positive q-axis current 3302 , and current intensity 3303 is shown.

[0111] Fig. 27 Shows the display when Fig.26Current diagram of positive d-axis current 3304 and new current intensity 3305 when the current configuration of FIG. 1 is subjected to magnetic field weakening behavior (i.e., a change in d-axis current 3301 in the positive direction). Fig.26 The current configuration applies a field weakening to increase the current intensity 3303 to a new current intensity 3305. These currents are represented as vectors. The positive d-axis current represents the flux enhancement motor described in the present invention.

[0112] Fig.28 A current diagram showing positive d-axis current 3401 , positive q-axis current 3402 , and current intensity 3403 is shown. Fig.28 The setting of indicates that the existing electric motor is experiencing field weakening. The conditions under which the maximum torque per ampere can be achieved at a constant current intensity 3403 can be set based on the vector angle of the d-axis current 3401 and the q-axis current 3402.

[0113] Fig.29 Shows the display when Fig.28 Current diagram of positive d-axis current 3404 and new current intensity 3406 when the current configuration of FIG. 1 is subjected to magnetic field weakening behavior (i.e., a change in d-axis current 3401 in the positive direction). Fig.28 The current configuration applies a magnetic field weakening to increase the current intensity 3403 to a new current intensity 3405. These currents are represented as vectors. Fig.29 It is shown that applying field weakening to a flux enhanced electric motor (positive d axis current) maintains a nearly constant current intensity (compare new current intensity 3407 to current intensity 3405). In other words, for the same amount of field weakening, the flux enhanced motor requires less current.

[0114] Inductance (denoted as L) is the property of a current-carrying circuit that causes magnetic flux. Flux linkage is equal to inductance times current. In a brushless DC motor, the stator is subject to two types of inductance: Ld along the d-axis and Lq along the q-axis. The field weakening flux is proportional to Ld times id (the current along the d-axis). Increasing Ld allows for higher field weakening capabilities. Adding center ribs between the magnets increases Ld. Spoke-type motors tend to have higher Ld. In other words, increasing the d-axis inductance will tend to improve field weakening performance.

[0115] Under certain conditions, a larger negative d-axis current can cause demagnetization. Therefore, since the flux enhanced motor operates with positive d-axis current, the flux enhanced motor is less susceptible to demagnetization under field weakening conditions and at higher currents during normal operating conditions.

[0116] Field weakening performance can be improved by increasing saliency, which is the difference between the inductance Ld along the d axis and the inductance Lq along the q axis. Torque can be determined as equal to the permanent magnet (PM) torque plus the reluctance torque. The reluctance torque is proportional to the equation (Ld – Lq) or Ld minus Lq. Permanent magnet synchronous reluctance motors (PMaSynRMs) tend to have greater saliency than some other motors.

[0117] In addition, using a narrower magnet will tend to improve the field weakening performance. For example, if all other factors are equal, we can expect Figure 5 The motor is 500 Figure 5B The motor 1600 has better field weakening performance.

[0118] An air gap along the q-axis (such as within the rotor or at the rotor circumference) acts as a flux barrier to reduce the Lq inductance value along the q-axis.

[0119] The torque of the electric motor can be calculated as follows: T = k(ψ pm i q +(L q –L d )i d i q ) In other words, torque is equal to permanent magnet torque plus reluctance torque. The equation (Lq-Ld) is also called "saliency". Lq is the inductance along the q axis, and Ld is the inductance along the d axis. Due to the saliency expression, changes in Ld relative to Lq change the torque of the motor.

[0120] Table 1 below shows the values ​​of magnet volume, no-load speed, no-load current, speed per unit current, average speed at 0.4-0.55 Nm, average current at 0.4-0.55 Nm, and average efficiency at 0.4-0.55 Nm for various motors in the drawings.

[0121]

[0122] Table 2 below shows the values ​​of magnet volume, no-load speed, no-load current, speed per unit current, average speed at 0.4-0.55 Nm, average current at 0.4-0.55 Nm, and average efficiency at 0.4-0.55 Nm for various motors in the drawings.

[0123]

[0124] Table 3 below shows the magnet volumes (mm) of the various motors in the attached figure. 3 ), no-load speed, no-load current (A), speed per unit current, average speed at 0.4-0.55 Nm, average current at 0.4-0.55 Nm and average efficiency at 0.4-0.55 Nm.

[0125]

[0126] Motors such as those disclosed herein may be used in a variety of power tools. Motors such as those disclosed herein may be used in power tools powered by battery packs. Motors such as those disclosed herein may be used in impact wrenches, nutrunners, pumps, or shear wrenches. Motors such as those disclosed herein may be used in power tools that operate until stalling and have a specific load region such that magnetic field weakening is appropriate.

[0127] Under the effect of magnetic field weakening, some motors disclosed in the present invention can achieve higher rundown speed, lower no-load current, and better efficiency when no-load. Representative features Representative features are listed in the following items, which may stand alone or in any combination with one or more of the features disclosed in the description and / or drawings.

[0128] Item 1: An electric power tool comprising: a battery pack interface configured to receive a removable and rechargeable battery pack; and A motor, the motor comprising: a stator comprising a plurality of stator teeth configured to receive a plurality of stator coils; and A rotor, comprising: a plurality of slots arranged in a spoke-type configuration, each of the plurality of slots comprising a magnet receiving portion configured to receive one or more magnets, Wherein, the rotor includes direct axis inductance and orthogonal axis inductance, wherein the direct axis inductance of the rotor is greater than the orthogonal axis inductance of the rotor, and The direct axis current of the motor is positive during the operation of the motor.

[0129] Item 2: The power tool according to Item 1, wherein each magnet receiving portion includes a centrally located center rib, which divides each magnet receiving portion into a first section and a second section.

[0130] Item 3: The power tool of Item 2, wherein the first section is configured to receive a first magnet and the second section is configured to receive a second magnet.

[0131] Item 4: The electric tool according to Item 3, wherein the rotor includes a total of 8 magnets.

[0132] Item 5: An electric power tool according to any of the preceding items, wherein the rotor includes a total of 4 magnets.

[0133] Item 6: The power tool according to any of the preceding items, wherein each of the plurality of slots includes an open air gap at the outer circumferential surface of the rotor.

[0134] Item 7: The power tool according to any of the preceding items, wherein the rotor includes a plurality of air gaps positioned between adjacent slots of the plurality of slots.

[0135] Item 8: A power tool according to any of the preceding items, wherein the rotor comprises a volume less than 3000 cubic millimeters ("mm 3 ”) magnet.

[0136] Item 9: The power tool according to Item 8, wherein the rotor includes a volume less than 1500 cubic millimeters ("mm 3 ”) magnet.

[0137] Item 10: An electric power tool comprising: a battery pack interface configured to receive a removable and rechargeable battery pack; and A motor, the motor comprising: a stator comprising a plurality of stator teeth configured to receive a plurality of stator coils; and A rotor, comprising: a plurality of slots, the plurality of slots being positioned perpendicular to a radial axis of the rotor, each of the plurality of slots comprising a magnet receiving portion configured to receive one or more magnets, Wherein, the rotor includes direct axis inductance and orthogonal axis inductance, wherein the direct axis inductance of the rotor is greater than the orthogonal axis inductance of the rotor, and The direct axis current of the motor is positive during the operation of the motor.

[0138] Item 11: The power tool according to Item 10, wherein each magnet receiving portion includes a centrally located center rib, wherein the center rib divides each magnet receiving portion into a first section and a second section.

[0139] Item 12: The power tool of Item 11, wherein the first section is configured to receive a first magnet and the second section is configured to receive a second magnet.

[0140] Item 13: The power tool according to Item 12, wherein the rotor includes a total of 8 magnets.

[0141] Item 14: A power tool according to any one of Items 10-13, wherein the rotor comprises a volume less than 3000 cubic millimeters ("mm 3 ”) magnet.

[0142] Item 15: A power tool according to any one of Items 10-14, wherein the rotor comprises a volume less than 2500 cubic millimeters ("mm 3 ”) magnet.

[0143] Item 16: The electric tool according to any one of Items 10 to 15, wherein the rotor includes a plurality of air gaps positioned on an outer circumferential surface of the rotor.

[0144] Item 17: The electric tool according to Item 16, wherein the plurality of air gaps are funnel-shaped, and each of the plurality of air gaps is located between adjacent grooves of the plurality of grooves.

[0145] Item 18: An electric tool comprising: a battery pack interface configured to receive a removable and rechargeable battery pack; and A motor, the motor comprising: a stator comprising a plurality of stator teeth configured to receive a plurality of stator coils; and A rotor, comprising: a plurality of slots, the plurality of slots being configured in pairs to form a V-shaped configuration, each of the plurality of slots comprising a magnet receiving portion configured to receive one or more magnets, each pair of the plurality of slots comprising a centrally located center rib positioned between a first slot of the pair and a second slot of the pair, Wherein, the rotor includes direct axis inductance and orthogonal axis inductance, wherein the direct axis inductance of the rotor is greater than the orthogonal axis inductance of the rotor, and The direct axis current of the motor is positive during the operation of the motor.

[0146] Item 19: The power tool according to Item 18, wherein the rotor includes a volume less than 3000 cubic millimeters ("mm 3 ”) magnet.

[0147] Item 20: The power tool according to Item 19, wherein the rotor comprises a volume less than 1500 cubic millimeters (“mm 3 ”) magnet.

[0148] Various features and advantages of the invention are set forth in the following claims.

Claims

1. An electric tool comprising: a battery pack interface configured to receive a removable and rechargeable battery pack; and A motor, the motor comprising: a stator comprising a plurality of stator teeth configured to receive a plurality of stator coils; and A rotor, comprising: a plurality of slots arranged in a spoke-type configuration, each of the plurality of slots including a magnet receiving portion configured to receive one or more magnets, Wherein, the rotor includes direct axis inductance and orthogonal axis inductance, wherein the direct axis inductance of the rotor is greater than the orthogonal axis inductance of the rotor, and The direct axis current of the motor is positive during the operation of the motor. 2 . The power tool of claim 1 , wherein each magnet receiving portion includes a centrally located center rib that divides each magnet receiving portion into a first section and a second section. 3 . The power tool of claim 2 , wherein the first section is configured to receive a first magnet and the second section is configured to receive a second magnet. The power tool according to claim 3 , wherein the rotor includes a total of 8 magnets.

5. The power tool according to claim 1, wherein the rotor includes a total of 4 magnets. 6 . The power tool of claim 1 , wherein each of the plurality of slots includes an open air gap at an outer circumferential surface of the rotor. 7 . The power tool of claim 1 , wherein the rotor includes a plurality of air gaps positioned between adjacent ones of the plurality of slots.

8. The power tool of claim 1, wherein the rotor comprises a volume less than 3000 cubic millimeters ("mm 3 ”) magnet.

9. The power tool of claim 8, wherein the rotor comprises a volume less than 1500 cubic millimeters ("mm 3 ”) magnet.

10. An electric tool comprising: a battery pack interface configured to receive a removable and rechargeable battery pack; and A motor, the motor comprising: a stator comprising a plurality of stator teeth configured to receive a plurality of stator coils; and A rotor, comprising: a plurality of slots, the plurality of slots being positioned perpendicular to a radial axis of the rotor, each of the plurality of slots comprising a magnet receiving portion configured to receive one or more magnets, Wherein, the rotor includes direct axis inductance and orthogonal axis inductance, wherein the direct axis inductance of the rotor is greater than the orthogonal axis inductance of the rotor, and The direct axis current of the motor is positive during the operation of the motor. 11 . The power tool of claim 10 , wherein each magnet receiving portion includes a centrally located center rib that divides each magnet receiving portion into a first section and a second section. 12 . The power tool of claim 11 , wherein the first section is configured to receive a first magnet and the second section is configured to receive a second magnet.

13. The power tool of claim 12, wherein the rotor includes a total of 8 magnets.

14. The power tool of claim 10, wherein the rotor comprises a volume less than 3000 cubic millimeters ("mm 3 ”) magnet.

15. The power tool of claim 10, wherein the rotor comprises a volume less than 2500 cubic millimeters ("mm 3 ”) magnet.

16. The power tool of claim 10, wherein the rotor includes a plurality of air gaps positioned on an outer circumferential surface of the rotor. 17 . The power tool of claim 16 , wherein the plurality of air gaps are funnel-shaped, and each of the plurality of air gaps is located between adjacent grooves of the plurality of grooves.

18. An electric tool comprising: a battery pack interface configured to receive a removable and rechargeable battery pack; and A motor, the motor comprising: a stator comprising a plurality of stator teeth configured to receive a plurality of stator coils; and A rotor, comprising: a plurality of slots, the plurality of slots being configured in pairs to form a V-shaped configuration, each of the plurality of slots comprising a magnet receiving portion configured to receive one or more magnets, each pair of the plurality of slots comprising a centrally located center rib positioned between a first slot of the pair and a second slot of the pair, Wherein, the rotor includes direct axis inductance and orthogonal axis inductance, wherein the direct axis inductance of the rotor is greater than the orthogonal axis inductance of the rotor, and The direct axis current of the motor is positive during the operation of the motor.

19. The power tool of claim 18, wherein the rotor comprises a volume less than 3000 cubic millimeters ("mm 3 ”) magnet.

20. The power tool of claim 19, wherein the rotor comprises a volume less than 1500 cubic millimeters ("mm 3 ”) magnet.

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