Power tool motor motor configuration

Abstract

Solves the problems of conventional technology. [Solution] The power tool may include a battery pack interface configured to receive a removable and rechargeable battery pack. The power tool includes a motor, which includes a stator having a plurality of stator teeth configured to receive a plurality of stator coils, and a rotor having a plurality of slots configured in a spoke-type configuration, each slot of the plurality of slots having a magnet housing portion configured to receive a magnet, the magnet having length and width, the length of the magnet being greater than half the width of one of the plurality of stator teeth.

Description

Technical Field

[0001] (Reference to Related Applications) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 496,723, filed on April 18, 2023, the entire content of which is incorporated herein by reference.

[0002] (Technical Field) The embodiments described herein relate to motors of power tools.

Summary of the Invention

[0003] The power tool described herein includes a battery pack interface configured to receive a removable and rechargeable battery pack, a stator including a plurality of stator teeth configured to receive a plurality of stator coils, and a rotor including a plurality of slots configured in a spoke-type configuration, each slot of the plurality of slots including a magnet housing portion configured to receive a magnet. The magnet includes a length and a width, and the length of the magnet is greater than half the width of one of the plurality of stator teeth.

[0004] In some aspects, the motor has an outer diameter between 43 millimeters and 55 millimeters.

[0005] In some aspects, the stator is a segmented stator.

[0006] In some aspects, the motor is a 9-slot 6-pole motor.

[0007] In some aspects, it is a 9-slot 8-pole motor.

[0008] In some aspects, the stator further includes a needle gap defined by a space between two adjacent stator coils of the plurality of stator coils.

[0009] In some embodiments, the magnet is made of neodymium iron boron, and the magnet is fixed to the magnet housing portion using an adhesive.

[0010] In some embodiments, the width of the magnet is given by the following formula

number

[0011] In some embodiments, the motor has higher efficiency at lighter loads when compared to a motor having a larger number of slots and poles.

[0012] In some embodiments, the motor has a higher peak power output value when compared to a motor having fewer slots and poles.

[0013] In some embodiments, the motor has a peak output power value of approximately 1,200 watts at 0.90 Nm.

[0014] In some embodiments, the motor has a peak output power approximately equal to that of an internal permanent magnet motor, and the motor has an outer diameter size that is about 50% smaller than that of an internal permanent magnet motor.

[0015] In some embodiments, the motor has approximately 13% greater output power when compared to an internal permanent magnet motor, and the motor includes an outer diameter size that is approximately 25% smaller than that of an internal permanent magnet motor.

[0016] In some embodiments, the motor has an output power increase of approximately 28% when compared to an internal permanent magnet motor, and the motor has an outer diameter size that is approximately the same as that of an internal permanent magnet motor.

[0017] In some embodiments, the motor has an output power increase of approximately 33% when compared to an internal permanent magnet motor, and the motor has an outer diameter size that is approximately 21% larger than that of an internal permanent magnet motor.

[0018] The motor described herein includes a stator having a plurality of stator teeth configured to receive a plurality of stator coils, and a rotor having a plurality of slots configured in a spoke-type configuration, each slot of the plurality of slots having a magnet housing portion configured to receive a magnet, the magnet having length and width. The length of the magnet is greater than half the width of one of the plurality of stator teeth.

[0019] In some embodiments, the stator is a segmented stator.

[0020] In some embodiments, the motor has an outer diameter between 43 mm and 55 mm, and the motor has 13% to 28% greater output power than the internal permanent magnet motor, while the internal permanent magnet motor has an outer diameter between 45 mm and 60 mm.

[0021] The power tool described herein includes a battery pack interface configured to receive a removable and rechargeable battery pack, and a motor having an outer diameter between 43 mm and 55 mm. The motor includes a segmented stator having a plurality of stator teeth configured to receive a plurality of stator coils, and a rotor having a plurality of slots configured in a spoke-type configuration, each slot of the plurality of slots having a magnet housing portion configured to receive a magnet, the magnet having length and width. The length of the magnet is greater than half the width of one of the plurality of stator teeth.

[0022] In some embodiments, the motor has 13% to 28% greater output power than the internal permanent magnet motor, and the internal permanent magnet motor has an outer diameter between 45 mm and 60 mm.

[0023] Before describing any embodiment in detail, it should be understood that this embodiment is not limited to the details of the configuration and arrangement of components shown in the following description or illustrated in the accompanying drawings in its application. Embodiments can or are implementable in a variety of ways. It should also be understood that the expressions and terms used herein are for descriptive purposes only and should not be considered limiting. The use of “including,” “comprising,” or “having” and their variations means including the items listed thereafter and their equivalents, as well as additional items. Unless otherwise specified or not particularly limited, the terms “mounted,” “connected,” “supported,” and “coupled” and their variations are used broadly and include both direct and indirect mounting, connection, support, and coupling.

[0024] Unless the context of use is clearly different, the articles "a," "an," and "the" should not be interpreted as meaning "one" or "only one." Rather, these articles should be interpreted as meaning "at least one" or "one or more." Similarly, when the terms "the" or "said" are used to refer to a noun previously introduced by the indefinite article "a" or "an," "the" and "said" mean "at least one" or "one or more," unless the context of use is clearly different.

[0025] In addition, embodiments may include hardware, software, and electronic components or modules, which may be illustrated and described for the purposes of discussion as if most of the components were implemented solely in hardware. However, one of ordinary skill in the art will recognize that, based on the reading of this detailed description, in at least one embodiment, an electronically-based aspect may be implemented in software that is executable by one or more processing units, such as a microprocessor and / or an application specific integrated circuit (ASIC) (e.g., stored on a non-transitory computer-readable medium). Thus, it should be noted that multiple hardware and software-based devices, as well as multiple different structural components, may be utilized to implement the embodiments. For example, the "server," "computing device," "controller," "processor," etc. described herein may include one or more processing units, one or more computer-readable media modules, one or more input / output interfaces, and various connections (e.g., a system bus) that connect the components.

[0026] For example, relative terms such as "about," "approximately," "substantially," etc., when used in relation to a quantity or a state, are understood by one of ordinary skill in the art to include the recited value and to have the meaning indicated by the context (e.g., the terms include, at a minimum, the degree of error associated with the measurement accuracy, the tolerances associated with a particular value [e.g., manufacturing, assembly, use, etc.], etc.). Such terms should also be considered as disclosing a range defined by the absolute values of two endpoints. For example, the expression "about 2 to about 4" also discloses the range of "2 to 4." Relative terms may refer to a percentage plus or minus of the indicated value (e.g., 1%, 3%, 10% or more).

[0027] While certain drawings illustrate hardware and software located within a particular device, it should be understood that these depictions are for illustrative purposes only. Functionality described herein as being performed by a single component may be performed by multiple components in a distributed manner. Similarly, functionality performed by multiple components may be integrated and performed by a single component. In some embodiments, the illustrated components may be combined or separated into separate software, firmware, and / or hardware. For example, logic and processing may be distributed across multiple electronic processors instead of being located and executed within a single electronic processor. Regardless of how they are combined or separated, hardware and software components may be located on the same computing device or distributed across different computing devices connected by one or more networks or other appropriate communication links. Similarly, a component described as performing a particular functionality may perform additional functionality not described herein. For example, a device or structure “configured” in a particular manner may be configured in at least that manner, but in ways not explicitly enumerated.

[0028] Accordingly, if a claim is made that an apparatus, method, or system includes, for example, a controller, control unit, electronic processor, computing device, logic element, module, memory module, communication channel or network, or other elements configured in a particular manner to perform a plurality of functions, then the claim or elements of the claim should be interpreted as meaning one or more such elements, for example, one or more elements collectively perform a plurality of functions as a set, or any one of the one or more elements is claimed to perform any one or more of the enumerated functions.

[0029] Other aspects of the embodiments will become apparent by considering the detailed description and the accompanying drawings.

Brief Description of the Drawings

[0030] [Figure 1] A side view of a power tool according to some embodiments is shown.

[0031] [Figure 2] A block diagram of the control system of the power tool of FIG. 1 according to some embodiments is shown.

[0032] [Figure 3] A battery pack for use with the power tool of FIG. 1 according to some embodiments is shown.

[0033] [Figure 4] A block diagram of the control system of the battery pack of FIG. 3 according to some embodiments is shown.

[0034] [Figure 5] A rotor including a spoke-type magnet configuration according to some embodiments is shown.

[0035] [Figure 6] A rotor including a spoke-type magnet configuration according to some embodiments is shown.

[0036] [Figure 7] A rotor including a spoke-type magnet configuration according to some embodiments is shown.

[0037] [Figure 8] A rotor including a spoke-type magnet configuration according to some embodiments is shown.

[0038] [Figure 9] A rotor including a spoke-type magnet configuration according to some embodiments is shown.

[0039] [Figure 10] The rotor is shown, including a spoke-type magnet configuration according to several embodiments.

[0040] [Figure 11A] The rotor is shown, including a spoke-type magnet configuration according to several embodiments. [Figure 11B] The rotor is shown, including a spoke-type magnet configuration according to several embodiments.

[0041] [Figure 12] The rotor is shown, including a spoke-type magnet configuration according to several embodiments.

[0042] [Figure 13A] The rotor is shown, including a spoke-type magnet configuration according to several embodiments. [Figure 13B] The rotor is shown, including a spoke-type magnet configuration according to several embodiments.

[0043] [Figure 14A] The rotor is shown, including a spoke-type magnet configuration according to several embodiments. [Figure 14B] The rotor is shown, including a spoke-type magnet configuration according to several embodiments.

[0044] [Figure 15] An enlarged view of a motor rotor, including spoke-type magnet configurations according to several embodiments, is shown.

[0045] [Figure 16] Several embodiments of internal permanent magnet motors are shown.

[0046] [Figure 17] This document shows a motor including a rotor having a spoke-type magnet configuration according to several embodiments.

[0047] [Figure 18] This document shows a motor including a rotor having a spoke-type magnet configuration according to several embodiments.

[0048] [Figure 19] This document shows a motor including a rotor having a spoke-type magnet configuration according to several embodiments.

[0049] [Figure 20] This graph shows the performance of multiple motors according to several embodiments.

[0050] [Figure 21] This graph shows the performance of multiple motors according to several embodiments.

[0051] [Figure 22] This graph shows the performance of multiple motors according to several embodiments.

[0052] [Figure 23] This graph shows the performance of multiple motors according to several embodiments. [Modes for carrying out the invention]

[0053] Figure 1 shows a power tool 100 including a permanent magnet motor. The power tool 100 is, for example, a hammer drill including a housing 102. 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 removable and rechargeable power tool battery pack (also called a battery pack). Although Figure 1 shows a hammer drill, in some embodiments the components described herein are incorporated into other types of power tools, including drill drivers, impact drivers, impact wrenches, angle grinders, circular saws, reciprocating saws, plate compactors, core drills, string trimmers, leaf blowers, vacuum cleaners, and the like. In permanent magnet motor power tools such as power tool 100, a switching element is selectively enabled and disabled by a control signal from a controller in order to selectively apply power from a power source (e.g., a battery pack) to drive the permanent magnet motor.

[0054] Figure 2 shows a control system 200 for a power tool 100. 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 212 or sensing circuits, one or more indicators 214, a user input module 216, a power input module 218, an inverter bridge or an FET switching module 220 (including, for example, multiple switching FETs), and a gate driver 224 for driving the FET switching module 220. In some embodiments, the motor 204 is a permanent magnet motor. The controller 202 includes, among other things, a combination of hardware and software that can control the operation of the power tool 100, monitor the operation of the power tool 100, and activate one or more indicators 214 (e.g., LEDs).

[0055] The controller 202 includes several electrical and electronic components that provide power, motion 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, microcontroller, electronic controller, electronic processor, or another suitable programmable device), memory 228, input unit 230, and output unit 232. The processing unit 226 includes, among other things, a control unit 234, an arithmetic logic unit 236 ("ALU"), and several registers 238, and is implemented using a known computer architecture (e.g., a modified Harvard architecture, a von Neumann architecture, etc.). The processing unit 226, memory 228, input unit 230, and output unit 232, as well as various modules or circuits connected to the controller 202, are connected by one or more control buses and / or data buses (e.g., a common bus 240). The control buses and / or data buses are generally shown in Figure 2 for illustrative purposes. The use of one or more control buses and / or data buses for interconnecting and communicating between various modules, circuits, and components will be known to those skilled in the art in view of the inventions described herein.

[0056] Memory 228 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 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 memory devices. Processing unit 226 is connected to memory 228 and executes software instructions that can be stored (e.g., during execution) in the RAM of memory 228, (e.g., on a substantially permanent basis) in the ROM of memory 228, or in another non-temporary computer-readable medium such as another memory or disk. Software included in the implementation of the power tool 100 may be stored in memory 228 of 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. Controller 202 is configured, among other things, to retrieve and execute instructions from memory 228 related to the control processes and methods described herein. In other configurations, the controller 202 may include additional components, fewer components, or different components.

[0057] 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) configured and operable to interface with the battery pack (e.g., connect mechanically, electrically, and communicatively). For example, power supplied to the power tool 100 by the battery pack 300 (see Figure 3) is supplied to the power input module 218 through the battery pack interface 206. The power input module 218 includes a combination of active and passive components for adjusting or controlling the power received from the battery pack 300 before it is supplied to the controller 202. The battery pack interface 206 also supplies power to an FET switching module 220, which is to be switched by a switching FET to selectively supply power to the motor 204. The battery pack interface 206 also includes a communication line 242 for providing a communication line or communication link between the controller 202 and the battery pack 300.

[0058] 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. Indicator 214 includes, for example, one or more light-emitting diodes ("LEDs"). Indicator 214 may be configured to display the status of the power tool 100 or information related to the power tool 100. For example, indicator 214 may be configured to show the measured electrical characteristics of the power tool 100, the status of the power tool, the status of the motor 204, etc. User input module 216 is operably coupled to controller 202 to select, for example, forward or reverse operating mode, torque setting and / or speed setting for the power tool 100 (for example, using torque and / or speed switches), etc. In some embodiments, user input module 216 includes a combination of digital and analog input or output devices necessary to achieve a desired operating level of the power unit 100, such as one or more knobs, one or more dials, one or more switches, one or more buttons, etc.

[0059] Figure 3 shows the battery pack 300. 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.

[0060] Figure 4 shows a control system for the 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 interface 404 (e.g., interface portion 304 of the battery pack 300 illustrated in Figure 3). The 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. The controller 400 includes a combination of hardware and software that can operate, among other things, to control the operation of the battery pack 300, monitor the status of the battery pack 300, enable or disable charging of the battery pack 300, enable or disable discharging of the battery pack 300, etc.

[0061] 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, microcontroller, electronic processor, 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 a known computer architecture (e.g., a modified Harvard architecture, a von Neumann architecture, etc.). The processing unit 412, the memory 414, the input unit 416, and the output unit 418, as well as various modules or circuits connected to the controller 400, are connected by one or more control buses and / or data buses (e.g., a common bus 426). The control buses and / or data buses are generally shown in Figure 4 for illustrative purposes. The use of one or more control buses and / or data buses for interconnecting and communicating between various modules, circuits, and components will be known to those skilled in the art in view of the inventions described herein.

[0062] 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 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 memory devices. Processing unit 412 is connected to memory 414 and executes software instructions that can be stored (e.g., during execution) in the RAM of memory 414, (e.g., on a substantially permanent basis) in the ROM of memory 414, or in another non-temporary computer-readable medium such as another memory or disk. Software included in the implementation of battery pack 300 may be stored in memory 414 of controller 400. The software includes, for example, firmware, one or more applications, program data, filters, rules, one or more program modules, and other executable instructions. Controller 400 is configured to retrieve and execute instructions from memory 414, among other things, related to the control processes and methods described herein. In other configurations, the controller 400 may include additional components, fewer components, or different components.

[0063] Interface 404 includes a combination of mechanical components (e.g., rails, grooves, latches, etc.) and electrical components (e.g., one or more terminals) configured and operable to interface (e.g., mechanically, electrically, and communicatively) the battery pack 300 with other devices (e.g., power tools, battery pack chargers, etc.). For example, interface 404 is configured to communicate with controller 400 via communication line 428.

[0064] Figure 5 shows a motor 500 for use in a power tool 100. The motor 500 includes a spoke-type magnet configuration. The motor 500 includes a stator 505 and a plurality of stator winding slots 510. The plurality of stator winding slots 510 are configured to receive a plurality of windings (also called stator coils). The motor 500 also includes a rotor 515. The rotor 515 includes a plurality of slots 520 configured in a spoke-type configuration, and each of the plurality of slots 520 includes a magnet housing portion 525 configured to receive a magnet 530. The magnets may be made from neodymium, ferrite, neodymium iron boron, or another type of magnetic material. In some examples, the magnets 530 may be fixed within the magnet housing portion 525 by injection molding, adhesive, or another method of firmly positioning the magnet. The magnet housing portion 525 includes a first portion 535 spaced a first radial distance from the rotor's center of rotation and a second portion 540 spaced a second radial distance from the rotor's center of rotation. In the illustrated embodiment, the second portion 540 includes inner ribs 545 configured to connect the magnet housing portions to each other via a central barrier. An air gap 550 is present between the inner ribs 545. The magnet housing portion 525 is configured to receive a magnet 530, which has a length 555 and a width 560.

[0065] In some cases, the length 555 of the magnet 530 is greater than half the width 565 of the stator teeth 570 (also called stator teeth). In some cases, the width 560 of the magnet 530 is determined based on the following formula.

number

[0066] Figure 6 shows a motor 600 for use in a power tool 100. The motor 600 includes a spoke-type magnet configuration. The motor 600 includes a stator 605 and a plurality of stator winding slots 610. The plurality of stator winding slots 610 are configured to receive a plurality of windings. The motor 600 also includes a rotor 615. The rotor 615 includes a plurality of slots 620 configured in a spoke-type configuration, and each slot of the plurality of slots 620 includes a magnet housing portion 625 configured to receive a magnet 630. The magnet 630 may be made of the same material as described above and / or may be fixed to the magnet housing portion 625 as described above. In the illustrated embodiment, the rotor 615 includes an open central rotor 635 that receives the motor shaft. The open central rotor 635 advantageously improves the overall electromagnetic performance of the motor 600 by about 5%. The magnet housing portion is configured to receive the magnet 630, which includes a length 640 and a width 645. In some cases, the length 640 of the magnet 630 must be greater than half the width 650 of the stator teeth 655. In some cases, the width 645 of the magnet 630 may be determined by equation 1 as described above.

[0067] Figure 7 shows a motor 700 for use in a power tool 100. The motor 700 includes a spoke-type magnet configuration. The motor 700 includes a stator 705 and a plurality of stator winding slots 710. The plurality of stator winding slots 710 are configured to receive a plurality of windings. The motor 700 also includes a rotor 715. The rotor 715 includes a plurality of slots 720 configured in a spoke-type configuration, each slot including a magnet housing portion 725 configured to receive a magnet 730. The magnet 730 may be made of the same material as described above and / or may be fixed to the magnet housing portion 725 as described above. The magnet housing portion includes a first portion 735 spaced a first radial distance from the rotation center of the rotor 715 and a second portion 740 spaced a second radial distance from the rotation center of the rotor 715. In the illustrated embodiment, the second portion 740 includes an open center rotor 745 and outer ribs 750 for each magnet housing portion 725. The outer ribs 750 are positioned to close a plurality of slots 720. The outer ribs include a length 755 and a width 760. For example, the width 760 of the outer ribs may be between 0.1 mm and 1.4 mm. The magnet housing portion is configured to receive magnets, which include a length 765 and a width 770. In some examples, the length 765 of the magnet 730 must be greater than half the width 775 of the stator teeth 780. In some examples, the width 775 of the magnet 730 may be determined by formula 1 as described above.

[0068] Figure 8 shows a motor 800 including a rotor 805 for use in a power tool 100. The rotor 805 includes a spoke-type magnet configuration. The rotor 805 includes a plurality of slots configured in the spoke-type configuration, each slot including a magnet housing portion 810. Each magnet housing portion 810 is configured to receive a magnet 815. The magnets 815 may be made of the same material as described above and / or may be fixed to the magnet housing portion 810 as described above. The magnets 815 include a length 820 and a width 825. In some examples, the length 820 of the magnet 815 must be greater than half the width 860 of the stator teeth 865. In some examples, the width 825 of the magnet 815 may be determined by Equation 1 as described above.

[0069] In the illustrated embodiment, the rotor 805 includes inner ribs 830 configured to connect the magnet housing portions 810 to each other via a central barrier 835 (e.g., a central ring or arc-shaped portion of the rotor 805). The inner ribs 830 are arranged alternately at intervals between a plurality of slots. Positioned between the inner ribs 830 are flux barriers or airspace barriers 840. In some examples, there are a plurality of inner ribs and a plurality of airspace barriers, with at least one of the airspace barriers being between a corresponding one of the plurality of inner ribs. The magnet housing portions 810 are exposed to the airspace barriers 840 on the inner portion of the rotor 805, and the magnet housing portions 810 include outer ribs 845 positioned on the outer portion 850 of the rotor 805. The outer ribs 845 include a length 855 and a width 860. For example, the width of the outer ribs 845 may be between 0.1 mm and 1.4 mm. In some embodiments, each outer rib 845 includes a concave portion 870 formed on the outer circumference of the rotor 805.

[0070] Figure 9 shows a motor rotor 900 including a spoke-type magnet configuration. The rotor 900 includes a plurality of slots 905 configured in a spoke-type configuration, each slot 905 including a magnet housing portion 910 configured to receive a magnet 915. The magnet 915 may be made of the same material as described above and / or may be fixed to the magnet housing portion 910 as described above. The magnet 915 includes a length 920 and a width 925. In some examples, the length 920 of the magnet 915 must be greater than half the width 960 of the stator teeth 965. In some examples, the width 925 of the magnet 915 may be determined by Equation 1 as described above.

[0071] In some embodiments, the magnet housing portion 910 includes a magnet housing portion 930, sometimes called a shoe, positioned on the inner circumference 935 of the magnet housing portion 910. The shoe is configured to help the magnet housing portion 910 securely house the magnet 915. In some cases, the thickness of the shoe is greater than 0.2 mm, and the space between each shoe is greater than 0.2 mm. In addition, in some embodiments, the magnet housing portion 910 includes an outer rib 940. The outer rib 940 is positioned on the outer circumference 945 of the magnet housing portion 910. The outer rib 940 includes a length 950 and a width 955. For example, the width of the outer rib 940 may be between 0.1 mm and 1.4 mm. In some embodiments, the rotor 900 includes an open central rotor 970 similar to the open central rotor 635 described above and illustrated in Figure 6.

[0072] Figure 10 shows a rotor 1000 used with a power tool 100. The rotor 1000 includes a spoke-type magnet configuration. The rotor 1000 includes a plurality of slots 1005 configured in a spoke-type configuration, each slot 1005 including a magnet housing portion 1010 configured to receive a magnet 1015. The magnet 1015 may be made of the same material as described above and / or may be fixed to the magnet housing portion 1010 as described above. The magnet 1015 includes a length 1020 and a width 1025. In some examples, the length 1020 of the magnet 1015 must be greater than half the width 1070 of the stator teeth 1075. In some examples, the width 1025 of the magnet 1015 may be determined by the formula described above. In some embodiments, the magnet housing portion 1010 includes an air gap 1030 located on the inner circumference 1035 of the magnet housing portion 1010. The gap 1030 separates the magnet housing portion from the central circumference 1040 of the rotor 1000. The gap 1030 includes an inner rib 1045 positioned between two of the magnet housing portions of the magnet housing portion 1010. In addition, in some embodiments, the magnet housing portion 1010 includes an outer rib 1050. The outer rib 1050 is positioned on the outer circumference 1055 of the magnet housing portion 1010. The outer rib 1050 includes a length 1060 and a width 1065. For example, the width of the outer rib 1050 may be between 0.1 mm and 1.4 mm. In some examples, the width 1025 of the magnet 1015 may be determined by formula 1 as described above.

[0073] Figures 11A and 11B show a rotor 1100 used with a power tool 100. In some cases, the rotor 1100 configured in Figures 11A and 11B has reduced magnetic flux leakage compared to alternative motor configurations such as the rotor 1000 illustrated and described with respect to Figure 10. The rotor 1100 includes a spoke-type magnet configuration. The rotor 1100 includes a plurality of slots 1105 configured in a spoke-type configuration, each slot including a magnet housing portion 1110 configured to receive a magnet 1115. The magnet 1115 may be made of the same material as described above and / or may be fixed to the magnet housing portion 1110 as described above. The magnet 1115 includes a length 1120 and a width 1125. In some examples, the length 1120 of the magnet 1115 must be greater than half the width 1190 of the stator teeth 1195. In some examples, the width 1125 of the magnet 1115 may be determined by the formula described above. In some embodiments, the rotor 1100 includes a plurality of alternating outer rib portions 1130 positioned on the outer circumference 1135 of the magnet housing portion 1110. The plurality of alternating outer rib portions 1130 include a length 1140 and a width 1145. In some cases, the width 1145 of the outer rib portion 1130 ranges from 0.1 mm to 1.4 mm. The length extends for a first longitudinal distance 1150 in the axial direction of the rotor 1100. In addition, the magnet housing portion 1110 includes a plurality of outer gaps 1155 spaced between each of the plurality of alternating outer rib portions 1130, such that the space between each of the plurality of alternating outer rib portions 1130 includes a length 1160 and a width 1165, with the length 1160 extending for a second longitudinal distance 1170 in the axial direction of the rotor 1100. In some examples, the outer gap 1155 includes a length and width approximately equal to the length 1160 and width 1165 of each of the multiple alternating outer rib sections 1130. In some examples, the width 1125 of the magnet 1115 may be determined by Equation 1 as described above.

[0074] In some embodiments, the magnet housing portion includes a plurality of internal gap portions 1175 positioned on the inner circumference 1180 of the magnet housing portion 1110. The plurality of internal gap portions 1175 separate the magnet housing portion 1110 from the central circumference 1185 of the rotor 1100. In some embodiments, the plurality of internal gap portions 1175 are spaced apart in the opposite configuration to the plurality of external rib portions 1130. For example, for a first longitudinal distance 1150, the magnet housing portion 1110 includes the external rib portions 1130 but does not include the internal gap portions 1175, and for a second longitudinal distance 1170, the magnet housing portion 1110 includes the internal gap portions 1175 but does not include the external rib portions 1130.

[0075] Figure 12 shows a rotor 1200 for use in a power tool 100. The rotor 1200 includes a spoke-type magnet configuration. The rotor 1200 includes a plurality of slots 1205 configured in a spoke-type configuration, each slot 1205 including a magnet housing portion 1210 configured to receive magnets. The magnets may be made of the same material as described above and / or may be fixed to the magnet housing portion 1210 as described above. The magnet housing portion 1210 includes a length 1215 and a width 1220. In some embodiments, the magnet housing portion 1210 includes an outer rib portion 1225, as also described above, the outer rib portion may range between 0.1 mm and 1.4 mm. The magnet housing portion 1210 also includes an inner shoe portion 1230 configured to securely hold the magnets. The inner shoe portion 1230 includes a first length 1235 and a first width 1240 on each side of the inner shoe portion 1230. In some embodiments, the inner shoe portion 1230 includes a convex portion 1245 and a concave portion 1250. In some embodiments, the magnet housing portion 1210 includes a plurality of inner shoe portions. For example, in some cases, the magnet housing portion 1210 includes two inner shoe portions, each of which is configured on either side of the magnet housing portion, and each of the two inner shoe portions is configured to hold a magnet within the magnet housing portion 1210.

[0076] In some embodiments, the rotor 1200 includes an overmolding shaft 1255 on the inner circumference of the rotor 1200. The overmolding may be a material injected, for example, between the laminated stack portion 1260 of the rotor 1200 and the shaft portion 1265 of the rotor 1200. For example, the material may be selected from the group consisting of injection-molded plastics, epoxy resins, polyurethanes, silicon steels, composite materials, thermal interface materials, etc. The laminated stack portion 1260 includes a gap 1270 formed between adjacent magnet housing portions 1210. In some embodiments, the gap 1270 is also filled with the injected material. In some examples, the width 1220 of the magnet for the magnet housing portion 1210 may be determined by formula 1 as described above.

[0077] Figures 13A and 13B show a rotor 1300 for use in a power tool 100. The rotor 1300 includes a spoke-type magnet configuration. The rotor 1300 includes a plurality of slots 1305 configured in a spoke-type configuration, each slot 1305 including a magnet housing portion 1310 configured to receive magnets. The magnets may be made of the same material as described above and / or may be fixed to the magnet housing portion 1310 as described above. The magnet housing portion 1310 includes a length 1315 and a width 1320. In some embodiments, the magnet housing portion 1310 includes an outer rib portion 1325 and an inner shoe 1330, and similarly includes an inner rib 1375 as described above. In some examples, the rotor 1300 includes a minimum interference fit 1335 between the outer circumference 1340 of the shaft and the inner circumference 1345 of the stacked stack. For example, in some embodiments, the minimum interference fit 1335 may be 10 microns or less. In some embodiments, the surface of the shaft includes a knurled portion 1350 extending a first circumferential distance 1355 around the shaft and a smooth portion 1360 extending a second circumferential distance 1365 around the shaft. In some examples, the rotor 1300 includes a crumple zone 1370 located in the inner portion of the rotor 1300, as shown in Figure 13B. In some cases, the crumple zone may be configured to compress or deform an inner rib 1375 during press fitting of the shaft. The stacked portion 1380 includes a gap 1385. In some examples, the width 1320 of the magnet for the magnet housing portion 1310 may be determined by formula 1 as described above.

[0078] Figure 14A shows a rotor 1400 for use with a power tool 100. The rotor 1400 includes a spoke-type magnet configuration. The rotor 1400 includes a plurality of slots 1405 configured in a spoke-type configuration, each slot 1405 including a magnet housing portion 1410 configured to receive magnets. The magnets may be made of the same material as described above and / or may be fixed to the magnet housing portion 1410 as described above. The plurality of slots 1405 and the magnet housing portion 1410 are similar to the slots and magnet housing portion described above. In some embodiments, the rotor includes a stainless steel ring portion 1415 inside the rotor 1400. In some examples, the width of the magnets for the magnet housing portion 1410 may be determined by Equation 1 as described above.

[0079] Figure 14B shows a rotor 1450 for use with a power tool 100. The rotor 1450 includes a first keyway 1455 located on a portion of the stacked rotor 1460 and a second keyway 1465 located on a portion of the shaft. In some embodiments, the first keyway 1455 and the second keyway 1465 reduce, eliminate, or prevent slippage of the stacked rotor 1460.

[0080] Figure 15 shows a rotor 1500 for use with a power tool 100. The rotor 1500 includes a plurality of slots 1505 configured in a spoke-type configuration, each slot 1505 including a magnet housing portion 1510 configured to receive a magnet 1512. The magnet 1512 may be made of the same material as described above and / or may be fixed to the magnet housing portion 1510 as described above. The magnet housing portion 1510 includes a length 1515 and a width 1520. In some embodiments, the magnet housing portion 1510 includes an outer rib portion 1525, an inner shoe 1530, and an inner rib 1575, as also described above. The rotor includes a laminated stack 1535 with a plurality of gaps 1540. In some cases, the gaps 1540 are filled with an injection-molded material such as injection-molded plastic 1545. The rotor 1500 also includes a shaft 1550 that extends through the rotor 1500 from a first end 1555 of the rotor 1500 to a second end 1560 of the rotor 1500. A first bearing 1570 is located at the first end 1555 of the rotor 1500. The rotor 1500 also includes a fan 1580 located at the second end of the rotor 1500. The rotor includes a second bearing 1585 located at the second end 1560 of the rotor and a plurality of C-rings 1590 configured to connect the second bearing 1585 to the shaft 1550 of the rotor 1500. In some embodiments, the shaft 1550 includes knurled surfaces for injection molding.

[0081] Figure 16 shows a motor 1600 for use in a power tool 100. Unlike the motor described above, motor 1600 is an internal rotor permanent magnet (IPM) motor and does not include a spoke-type configuration. Motor 1600 includes a stator 1605 and a rotor 1610. The stator includes a plurality of stator teeth 1615 and a plurality of stator winding slots 1620 configured to receive a plurality of windings. Each of the plurality of stator teeth 1615 includes a projection 1625 configured to help hold the stator winding. In the illustrated example, the stator 1605 is shown to include a segmented stator. A segmented stator consists of a plurality of segments rather than a single continuous part. Each segment of the stator 1605 is made up of, for example, a laminated sheet and carries a portion of the stator winding slots 1620. During the manufacturing process, the segments are mechanically and electrically connected to form the stator 1605. The illustrated example includes a segmented stator, but it should be understood that in some embodiments, the motor 1600 may not include a segmented stator.

[0082] The rotor 1610 includes a plurality of slots, each slot including a magnet housing portion 1645 configured to receive a magnet 1650. The magnet 1750 may be made of the same material as described above and may be fixed to the magnet housing portion 1645 as described above. The magnet 1650 includes a length 1655 and a width 1660. The rotor additionally includes an inner rotor portion 1630 and a plurality of outer rotor portions 1635. Each of the plurality of outer rotor portions 1635 is configured to connect to another outer rotor portion of the plurality of outer rotor portions 1635 via an outer rib 1665. In addition, the outer rib 1665 is configured to connect to the inner rotor portion 1630 via a connecting portion 1675. In some cases, the outer rib 1665 and the connecting portion 1675 form a gap 1670, which is positioned adjacent to the magnet housing portion 1645. In some cases, the outer rib 1665 and connecting portion 1675 are configured to help hold the magnet 1650 within the magnet housing portion 1645. In some examples, the motor 1600 has an outer diameter of 40 to 60 mm and an axial length of 24 mm.

[0083] Figure 17 shows a motor 1700 for use in a power tool 100. The motor 1700 includes a spoke-type magnet configuration. The motor 1700 is shown as a 6-slot 4-pole (6s4p) motor, but may be configured to include more or fewer slots and / or poles or any number of slots and poles. For example, in another embodiment, the motor 1700 may be a 9-slot 8-pole (9s8p) motor. The motor 1700 includes a stator 1705 and a rotor 1710. The stator includes a plurality of stator teeth 1715 and a plurality of stator winding slots 1720 configured to accept a plurality of windings. Each of the plurality of stator teeth 1715 includes a projection 1725 configured to help hold a stator winding.

[0084] The motor 1700 also includes a needle gap 1730, also called a slot gap. The needle gap 1730 may be defined by the space between adjacent windings that are accommodated by a plurality of stator winding slots 1720. In some examples, the needle gap 1730 is configured to provide electrical insulation to prevent short circuits between windings. In addition, the needle gap 1730 can reduce eddy currents in the stator 1705, further improving the efficiency of the motor 1700. Furthermore, the needle gap 1730 can allow for a higher slot fill factor, which is the ratio of windings to the total cross-sectional area of ​​the plurality of stator winding slots 1720. In some cases, a higher slot fill factor leads to improved motor efficiency. In some cases, the motor 1700 has an outer diameter between 43 mm and 55 mm. In some cases, the motor 1700 has an axial length of 24 mm. In some embodiments, the motor 1700 includes a segmented stator 1705. In other embodiments, the motor 1700 does not include a segmented stator.

[0085] The rotor 1710 includes a plurality of slots configured in a spoke-type configuration, each slot including a magnet housing portion 1745 configured to receive a magnet 1750. The magnet 1750 may be made of the same material as described above and / or may be fixed to the magnet housing portion 1745 as described above. The magnet 1750 includes a length 1755 and a width 1760. The rotor 1710 additionally includes a plurality of inner portions 1735 and outer ribs 1740 positioned between each of the inner portions 1735. The outer ribs 1740 are configured to hold the magnet 1750 within the magnet housing portion 1745. In some examples, the length 1755 of the magnet 1750 must be greater than half the width of one of the plurality of stator teeth 1815. In some examples, the width 1760 of the magnet 1750 may be determined by formula 1 as described above.

[0086] Figure 18 shows a motor 1800 for use in a power tool 100. The motor 1800 includes a spoke-type magnet configuration. The motor 1800 is shown as a 9-slot 6-pole (9s6p) motor, but may be configured to include more or fewer slots and / or poles. The motor 1800 includes a stator 1805 and a rotor 1810. The stator includes a plurality of stator teeth 1815 and a plurality of stator winding slots 1820 configured to accept a plurality of windings. Each of the plurality of stator teeth 1815 includes a protruding portion 1825 configured to help hold the stator winding. The motor 1800 includes a needle gap 1830, similar to the needle gap described above. The needle gap 1830 is the space between adjacent windings accepted by the stator slots 1820. In some cases, the motor 1800 has an outer diameter between 43 mm and 55 mm. In some cases, the motor 1800 has an axial length of 24 millimeters. In some embodiments, the motor 1800 includes a segmented stator 1805. In other embodiments, the motor 1800 does not include a segmented stator.

[0087] The rotor 1810 includes a plurality of slots configured in a spoke-type configuration, each slot including a magnet housing portion 1850 configured to receive a magnet 1855. The magnet 1855 may be made of the same material as described above and / or may be fixed to the magnet housing portion 1850 as described above. The magnet 1855 includes a length 1860 and a width 1865. The rotor additionally includes a plurality of inner portions 1835 and outer ribs 1840 positioned between each of the inner portions 1835. The outer ribs 1840 are configured to hold the magnet 1855 within the magnet housing portion 1850. In the illustrated embodiment, the rotor 1810 further includes a gap 1845 between the outer ribs 1840 and the magnet 1855. In some embodiments, there is no gap between the outer ribs 1840 and the magnet 1855. In some cases, the length 1860 of the magnet 1855 must be greater than half the width 1865 of one of the multiple stator teeth 1815. In some cases, the width 1865 of the magnet 1855 may be determined by equation 1 as described above.

[0088] Figure 19 shows a motor 1900 for use in a power tool 100. The motor 1900 includes a spoke-type magnet configuration. The motor 1900 is shown as a 9-slot 8-pole (9s8p) motor, but may be configured to include more or fewer slots and / or poles. The motor 1900 includes a stator 1905 and a rotor 1910. The stator includes a plurality of stator teeth 1915 and a plurality of stator winding slots 1920 configured to accept a plurality of windings. Each of the plurality of stator teeth 1915 includes a projection 1925 configured to help hold the stator winding. In the illustrated example, the stator 1905 is shown to include a segmented stator, which may include a configuration similar to that described above. Although the motor 1900 includes a segmented stator, in some embodiments the motor 1900 may not be segmented. In some cases, the motor 1900 has an outer diameter between 43 mm and 55 mm. In some cases, the motor 1900 has an axial length of 24 millimeters.

[0089] The rotor 1910 includes a plurality of slots configured in a spoke-type configuration, each slot including a magnet housing portion 1945 configured to receive a magnet 1940. The magnet 1940 may be made of the same material as described above and / or may be fixed to the magnet housing portion 1745 as described above. The magnet 1940 includes a length 1955 and a width 1960. The rotor additionally includes a plurality of inner portions 1930 and outer ribs 1935 positioned between each of the inner portions 1930. The outer ribs 1935 are configured to hold the magnet 1940 within the magnet housing portion 1945. In some examples, the length 1655 of the magnet 1940 must be greater than half the width of one stator tooth of the plurality of stator teeth. In some examples, the width 1960 of the magnet 1940 may be determined by formula 1 as described above.

[0090] Figure 20 is a graph showing the performance of some of the motors described herein. The illustration includes Graph 2000, which includes the X-axis for torque in Newton-meters (Nm) and the Y-axis for efficiency (measured as a percentage), power output (measured in watts), motor current (measured in amperes), and motor speed (measured in revolutions per minute [RPM]). Graph 2000 includes benchmark IPM efficiency 2002 and segmented IPM efficiency 2004, such as for motor 1600. As previously mentioned, many of the motors 1700, 1800, and 1900 may include multiple slot and pole configurations, such as 6-slot 4-pole (6s4p), 9-slot 6-pole (9s6p), or 9-slot 8-pole (9s8p). Graph 2000 includes spoke 6s4p efficiency 2018 and segmented spoke 6s4p efficiency 2020. Graph 2000 further includes spoke 9s6p efficiency 2034 and segmented spoke 9s6p efficiency 2036. Graph 2000 also includes spoke 9s8p efficiency 2050 and segmented spoke 9s8p efficiency 2052. As shown in Graph 2000, in some cases, lower slot / pole motors, such as motor 1600, may have higher efficiency at lighter loads or lower torque values. In some cases, higher slot / pole motors may have lower efficiency at lighter loads. In some examples, the segmented spoke stall torque is approximately the same as that of the benchmark IPM motor.

[0091] Graph 2000 further includes benchmark IPM output power 2006 and segmented IPM efficiency 2008, such as for motor 1600. Graph 2000 also includes spoke 6s4p output power 2022 and segmented spoke 6s4p output power 2024. Graph 2000 further includes spoke 9s6p output power 2038 and segmented spoke 9s6p output power 2040. Graph 2000 further includes spoke 9s8p output power 2054 and segmented spoke 9s8p output power 2056. As shown by spoke 9s6p output power 2038 and segmented spoke 9s6p output power 2040, higher pole motor designs, such as motor 1800, have higher peak power values. For example, segmented spoke 9s6p output power 2040 includes a peak output power value of approximately 1200 watts at 0.90 Nm. In some embodiments, spoke motors have a peak output power that is approximately 10–20% higher when compared to a benchmark IPM motor.

[0092] Graph 2000 further includes benchmark IMP current 2010 and segmented IPM current 2012, as described for motor 1600. Graph 2000 also includes spoke 6s4p current 2026 and segmented spoke 6s4p current 2028. Graph 2000 further includes spoke 9s6p current 2042 and segmented spoke 9s6p current 2044. Graph 2000 further includes spoke 9s8p current 2058 and segmented spoke 9s8p current 2060. Graph 2000 further includes benchmark IMP RPM 2014 and segmented IPM RPM, as described for motor 1600. Graph 2000 includes 2016 and 2030 spoke 6s4p RPM and 2032 segmented spoke 6s4p RPM. Graph 2000 further includes spoke 9s6p RPM Graph 2000 further includes 2046 and segmented spoke 9s6p RPM 2048. Graph 2000 includes spoke 9s8p RPM 2062 and segmented spoke 9s8p RPM This includes 2064. Specific comparisons of conventional IPM motors with spoke-configuration motors are shown in Figures 21-23 and described below.

[0093] Figure 21 is a graph showing the performance of some of the segmented spoke motors described herein compared to IPM motors. The illustration includes Graph 2100, which, like Graph 2000 above, includes torque in Newton meters (Nm) on the X axis and efficiency, output power, motor current, and motor speed on the Y axis. Graph 2100 includes efficiency 2102, output power 2204, current 2106, and speed 2108 for several motor configurations. As previously mentioned, motors 1700, 1800, and 1900 may include outer diameters in the range of 43 mm to 55 mm. In the example shown in Figure 21, the IPM motor includes an outer diameter of 60 mm. In some examples, Graph 2100 includes efficiency 2110 for the IPM motor, efficiency 2118 for the 43 mm segmented spoke motor, and efficiency 2126 for the 55 mm segmented spoke motor. Graph 2100 includes the output power 2112 of the IPM motor, the output power 2120 of the 43mm segmented spoke motor, and the output power 2128 of the 55mm segmented spoke motor. Graph 2100 also includes the current 2114 of the IPM motor, the current 2122 of the 43mm segmented spoke motor, and the current 2130 of the 55mm segmented spoke motor. Graph 2100 also includes the speed 2116 of the IPM motor, the current 2124 of the 43mm segmented spoke motor, and the current 2132 of the 55mm segmented spoke motor. Table 1 below is a comparison of the motors shown in Graph 2100, including a comparison of motor outer diameter, peak output power, and motor size. [Table 1]

[0094] As shown in Graph 2100 and demonstrated in Table 1, a 43mm segmented spoke motor has nearly the same peak output power as an IPM motor with an outer diameter size reduced by approximately 50%. In addition, a 55mm segmented spoke motor has an increase in output power of approximately 13% with an outer diameter size reduction of approximately 25%. As demonstrated by Graph 2100 and Table 1, a 43mm segmented spoke motor results in a significant size reduction at similar power output when compared to an IPM motor, while a 55mm segmented spoke motor results in a significant increase in output power with a remarkable size reduction and similar power output when compared to an IPM motor.

[0095] Figure 22 is a graph showing the performance of some of the segmented spoke motors described herein when compared to IPM motors. The illustration includes Graph 2200, which, like Graphs 2000 and 2100 above, includes torque in Newton meters (Nm) on the X axis and efficiency, output power, motor current, and motor speed on the Y axis. Graph 2200 includes efficiency 2202, output power 2204, current 2206, and speed 2208 for several motor configurations. As previously mentioned, motors 1700, 1800, and 1900 may include outer diameters in the range of 43 mm to 55 mm. In the example shown in Figure 22, the IPM motor includes an outer diameter of 50 mm. In some examples, Graph 2200 includes IPM motor efficiency 2210, 43 mm segmented spoke motor efficiency 2218, 50 mm segmented spoke motor efficiency 2226, and 55 mm segmented spoke motor efficiency 2234. Graph 2200 includes IPM motor output power 2212, 43mm segmented spoke motor output power 2220, 50mm segmented spoke motor output power 2228, and 55mm segmented spoke motor output power 2236. Graph 2200 also includes IPM motor current 2214, 43mm segmented spoke motor current 2222, 50mm segmented spoke motor current 2230, and 55mm segmented spoke motor current 2238. Graph 2200 also includes IPM motor speed 2216, 43mm segmented spoke motor speed 2224, 50mm segmented spoke motor speed 2232, and 55mm segmented spoke motor speed 2240. Table 2 below is a comparison of the motors shown in Graph 2200, including a comparison of motor outer diameter, peak output power, and motor size. [Table 2]

[0096] As shown in Graph 2200 and demonstrated in Table 2, a 43mm segmented spoke motor has approximately 16% more power while having approximately 26% smaller outer diameter when compared to an IPM motor. A 50mm segmented spoke motor has approximately 28% more power while having almost the same outer diameter when compared to an IPM motor. A 55mm segmented spoke motor has approximately 33% more power and comes with approximately 21% larger outer diameter. As demonstrated by Graph 2200 and Table 2, a 43mm segmented spoke motor results in a significant size reduction for similar power output when compared to an IPM motor, and a 50mm segmented spoke motor results in a significant increase in power output for similar outer diameter when compared to an IPM motor. A 55mm segmented spoke motor includes an even greater increase in power output when compared to both a 50mm segmented spoke motor and an IPM motor.

[0097] Figure 23 is a graph showing the performance of some of the segmented spoke motors described herein when compared to IPM motors. The illustration includes graph 2300, which, like graphs 2000, 2100, and 2200 above, includes torque in Newton meters (Nm) on the X axis and efficiency, output power, motor current, and motor speed on the Y axis. Graph 2300 includes efficiency 2302, output power 2304, current 2306, and speed 2308 for several motor configurations. As previously mentioned, motors 1700, 1800, and 1900 may include outer diameters in the range of 43 mm to 55 mm. In the example shown in Figure 23, the IPM motor includes an outer diameter of 45 mm. In some examples, Graph 2300 includes IPM motor efficiency 2310, 43mm segmented spoke motor efficiency 2318, 45mm segmented spoke motor efficiency 2326, and 50mm segmented spoke motor efficiency 2334. Graph 2300 includes IPM motor output power 2312, 43mm segmented spoke motor output power 2320, 45mm segmented spoke motor output power 2328, and 50mm segmented spoke motor output power 2336. Graph 2300 includes IPM motor current 2314, 43mm segmented spoke motor current 2322, 45mm segmented spoke motor current 2330, and 50mm segmented spoke motor current 2338. Graph 2300 includes IPM motor speed 2316, 43mm segmented spoke motor speed 2324, 45mm segmented spoke motor speed 2332, and 50mm segmented spoke motor speed 2340. Table 2 below is a comparison of the motors shown in Graph 2300, including a comparison of motor outer diameter, peak power output, and motor size. [Table 3]

[0098] As shown in Graph 2300 and demonstrated in Table 3, a 43mm segmented spoke motor has approximately 31% more power while having approximately 9% smaller outer diameter when compared to an IPM motor. A 45mm segmented spoke motor has approximately 38% more power while having almost the same outer diameter when compared to an IPM motor. A 50mm segmented spoke motor has approximately 46% more power, accompanied by approximately 23% larger outer diameter. As demonstrated by Graph 2300 and Table 3, a 43mm segmented spoke motor results in a significant size reduction with a significant increase in power output when compared to an IPM motor, and a 45mm segmented spoke motor results in a significant increase in power output with similar outer diameter when compared to an IPM motor. A 50mm segmented spoke motor includes an even greater increase in power output when compared to an IPM motor.

[0099] Therefore, the embodiments described herein provide a power tool including a spoke-type motor. Various configurations and advantages are described in the following claims.

Claims

1. A battery pack interface configured to receive a removable and rechargeable battery pack, A motor, including, the motor is A stator including multiple stator teeth configured to receive multiple stator coils, A rotor including multiple slots configured in a spoke-type configuration, Each of the plurality of slots includes a magnet housing portion configured to receive a magnet, The magnet includes a length and a width, wherein the length of the magnet is greater than half the width of one of the plurality of stator teeth. Power tools.

2. The power tool according to claim 1, wherein the motor has an outer diameter between 43 mm and 55 mm.

3. The power tool according to claim 1, wherein the stator is a segmented stator.

4. The power tool according to claim 1, wherein the motor is a 9-slot 6-pole motor.

5. The power tool according to claim 1, wherein the motor is a 9-slot 8-pole motor.

6. The power tool according to claim 1, wherein the stator further includes a needle gap defined by the space between two adjacent stator coils of the plurality of stator coils.

7. The power tool according to claim 1, wherein the magnet is made of neodymium iron boron, and the magnet is fixed to the magnet housing portion using an adhesive.

8. The width of the magnet is given by the following formula [Math 3] Determined by, The power tool according to claim 1.

9. The power tool according to claim 1, wherein the motor has higher efficiency at lighter loads when compared with a motor having a larger number of slots and poles.

10. The power tool according to claim 1, wherein the motor has a higher peak output power value when compared with a motor having fewer slots and poles.

11. The power tool according to claim 1, wherein the motor has a peak output power value of approximately 1,200 watts at 0.90 N-m.

12. The power tool according to claim 1, wherein the motor has a peak output power substantially equal to that of the internal permanent magnet motor, and the motor has an outer diameter size that is approximately 50% smaller than that of the internal permanent magnet motor.

13. The power tool according to claim 1, wherein the motor has an output power about 13% greater when compared to an internal permanent magnet motor, and the motor has an outer diameter size about 25% smaller than that of the internal permanent magnet motor.

14. The power tool according to claim 1, wherein the motor has an output power increase of about 28% when compared with an internal permanent magnet motor, and the motor has an outer diameter size substantially equal to that of the internal permanent magnet motor.

15. The power tool according to claim 1, wherein the motor has an output power increase of about 33% when compared to an internal permanent magnet motor, and the motor has an outer diameter size that is about 21% larger than that of the internal permanent magnet motor.

16. A stator including multiple stator teeth configured to receive multiple stator coils, A rotor comprising a plurality of slots configured in a spoke-type configuration, wherein each of the plurality of slots includes a magnet housing portion configured to receive a magnet, The magnet includes a length and a width, wherein the length of the magnet is greater than half the width of the stator teeth among the plurality of stator teeth. Motor.

17. The motor according to claim 16, wherein the stator is a segmented stator.

18. The motor according to claim 16, wherein the motor has an outer diameter between 43 mm and 55 mm, the motor has an output power 13% to 28% greater than that of the internal permanent magnet motor, and the internal permanent magnet motor has an outer diameter between 45 mm and 60 mm.

19. A battery pack interface configured to receive a removable and rechargeable battery pack, A motor having an outer diameter between 43 mm and 55 mm, the motor is A segmented stator including multiple stator teeth configured to receive multiple stator coils, A rotor comprising a plurality of slots configured in a spoke-type configuration, wherein each of the plurality of slots includes a magnet housing portion configured to receive a magnet, The magnet includes a length and a width, wherein the length of the magnet is greater than half the width of the stator teeth among the plurality of stator teeth. Power tools.

20. The power tool according to claim 19, wherein the motor has an output power 13% to 28% greater than that of the internal permanent magnet motor, and the internal permanent magnet motor has an outer diameter between 45 mm and 60 mm.

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