Power tool

Abstract

A power tool can include a battery pack interface configured to receive a removable and rechargeable battery pack. An apparatus can include a motor including 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 spider configuration, each of the plurality of slots including a magnet housing portion configured to receive a magnet, a central barrier, a plurality of inner ribs configured to connect the magnet housing portions of the plurality of slots to each other via the central barrier, at least one air space barrier between the plurality of inner ribs, and wherein the magnet housing portions of the plurality of slots are exposed to the at least one air space barrier.

Description

[0001] Related applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 385,855, filed December 2, 2022, and U.S. Provisional Patent Application No. 63 / 496,723, filed April 18, 2023. Technical Field

[0003] The specific embodiments described in this utility model relate to motors for power tools. Utility Model Content

[0004] The power tool of this invention includes a battery pack interface and a motor. The battery pack interface is configured to receive a removable and rechargeable battery pack. The motor includes a stator and a rotor. The stator includes a plurality of stator teeth configured to receive a plurality of stator coils, and the rotor includes a plurality of slots configured in a spoke-like structure. Each of the plurality of slots includes a magnet housing portion configured to receive a magnet. The rotor also includes a central barrier and a plurality of inner ribs configured to connect at least one magnet housing portion of the plurality of slots to the central barrier. The rotor also includes at least one air space barrier between the plurality of inner ribs. At least one magnet housing portion of the plurality of slots is exposed to at least one air space barrier.

[0005] In some respects, the magnet includes a length, and this length is greater than half the width of one of the stator teeth among the plurality of stator teeth.

[0006] In some respects, the magnet includes the magnet width, which is determined based on the rotor diameter, the stator tooth width, and the number of poles of the motor.

[0007] In some aspects, the rotor further includes an outer rib positioned at the outer circumference of the rotor, the outer rib being configured to retain the first magnet within the first magnet housing portion.

[0008] In some aspects, the rotor further includes a second outer rib positioned at the outer circumference of the rotor, the second outer rib being configured to retain the second magnet within the second magnet housing portion.

[0009] In some respects, the outer ribs include a width between approximately 0.1 mm and 1.4 mm.

[0010] In some respects, the outer ribs include recesses formed on the outer circumference of the rotor.

[0011] The power tool of this invention includes a battery pack interface and a motor. The battery pack interface is configured to receive a removable and rechargeable battery pack. The motor includes a stator and a rotor. The stator includes a plurality of stator teeth configured to receive a plurality of stator coils. The rotor includes a rotor shaft, a rotor shaft portion, and a laminated stack portion. The rotor includes a plurality of slots configured in a spoke-like structure. Each of the plurality of slots includes a magnet housing portion configured to receive a magnet. The rotor includes a plurality of outer rib portions positioned on the outer circumference of the magnet housing portion. Each of the plurality of outer rib portions includes a first length extending a first distance in the axial direction of the rotor. The rotor includes a plurality of inner shoe portions positioned on the magnet housing portion. Each of the plurality of inner shoe portions includes a protrusion and a recess. An overmolded part includes material injected between the laminated stack portion and the rotor shaft portion.

[0012] In some respects, the magnet includes a length, and this length is greater than half the width of one of the stator teeth among the plurality of stator teeth.

[0013] In some respects, the magnet includes the magnet width, which is determined based on the rotor diameter, the stator tooth width, and the number of poles of the motor.

[0014] In some respects, each of the plurality of outer rib portions includes a width ranging from about 0.1 mm to 1.4 mm.

[0015] In some respects, each of the plurality of inner boot sections includes a first length and a first width.

[0016] In some respects, multiple inner boot sections are configured to hold the magnet within the magnet housing section.

[0017] In some respects, the material injected between the laminated stack portion and the rotor shaft portion is selected from one of the group consisting of injection-molded plastics, epoxy resins, polyurethanes, silicon steel, composite materials, and thermal interface materials.

[0018] The power tool of this invention includes a battery pack interface and a motor. The battery pack interface is configured to receive a removable and rechargeable battery pack. The motor includes a stator and a rotor. The stator includes a plurality of stator teeth configured to receive a plurality of stator coils. The rotor includes a stack of laminations and a plurality of slots configured in a spoke-like structure. Each of the plurality of slots includes a magnet housing portion configured to receive a magnet. The rotor includes a shaft including a knurled portion extending a first circumferential distance around the shaft and a smooth portion extending a second circumferential distance around the shaft. The rotor includes a corrugated region located on an internal portion of the rotor. The corrugated region is configured to deform the inner ribs of the rotor.

[0019] In some respects, the magnet includes a length that is greater than half the width of one of the stator teeth among the plurality of stator teeth.

[0020] In some respects, the magnet includes the magnet width, which is determined based on the rotor diameter, the stator tooth width, and the number of poles of the motor.

[0021] In some respects, the rotor further includes a minimum interference fit between the outer circumference of the shaft and the inner circumference of the stacked laminations, the minimum interference fit being less than or equal to 10 micrometers.

[0022] In some respects, the folded areas are further configured to deform the inner ribs during press fitting.

[0023] In some aspects, the rotor further includes a first keyway positioned on a first portion of the lamination stack and a second keyway positioned on a second portion of the shaft, the first and second keyways being configured to prevent slippage of the lamination stack.

[0024] Before explaining any implementation in detail, it should be understood that the implementation is not limited in application to the details of the configuration and arrangement of the components described in the following description or shown in the drawings. The implementation can be practiced or implemented in various ways. Furthermore, it should be understood that the wording and terminology used in this invention are for illustrative purposes and should not be considered restrictive. The use of "comprising," "including," or "having," and variations thereof, is intended to cover the items listed thereafter and their equivalents, as well as additional items. Unless otherwise stated or limited, the terms "mounted," "connected," "supported," and "coupled," and variations thereof, are used broadly and cover direct and indirect mounting, connection, support, and coupling.

[0025] Unless the context explicitly indicates otherwise, the articles “a,” “an,” and “the” should not be interpreted as meaning “one” or “only one.” Instead, 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 articles “a” or “an,” “the” and “said” mean “at least one” or “one or more” unless the usage explicitly indicates otherwise.

[0026] Furthermore, it should be understood that implementations may include hardware, software, and electronic components or modules, and for the purposes of discussion, the illustrations and descriptions of these components or modules may be presented as if most components were implemented solely in hardware. However, those skilled in the art, based on reading this detailed description, will recognize that in at least one implementation, the electronic aspects may be implemented as software (e.g., stored on a non-transitory computer-readable medium) executable by one or more processing units (such as microprocessors and / or application-specific integrated circuits (“ASICs”)). Therefore, it should be noted that implementations may be implemented using a plurality of hardware and software-based devices and a plurality of different structural components. For example, “server,” “computing device,” “controller,” “processor,” etc., as described in the specification may include one or more processing units, one or more computer-readable medium modules, one or more input / output interfaces, and various connections of the connecting components (e.g., system buses).

[0027] Related terms used in conjunction with quantities or conditions, such as, for example, “about,” “approximately,” “generally,” etc., will be understood by one of ordinary skill in the art to include the stated value and have a meaning defined by the context (e.g., the term includes at least the degree of error associated with measurement accuracy, the tolerance associated with a particular value [e.g., manufacturing, assembly, use, etc.]). Such terms should also be considered to disclose a range defined by the absolute values ​​of the two endpoints. For example, the expression “about 2 to about 4” also discloses a range of “2 to 4.” Relative terms may refer to a percentage added to or subtracted from the indicated value (e.g., 1%, 5%, 10%).

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

[0029] Therefore, in the claims, if the device, method, or system is claimed to include, 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 certain way to perform, for example, a plurality of functions, then the claim or claim element should be interpreted as referring to one or more such elements, any one of which is configured to, for example, implement any one or more of the plurality of functions, such that the one or more elements together perform the plurality of functions.

[0030] Other aspects of the various embodiments will become apparent upon careful reading of the detailed description and accompanying drawings. Attached Figure Description

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

[0032] Figure 2 The following are illustrated according to some embodiments. Figure 1 A block diagram of the control system of a power tool.

[0033] Figure 3 The diagram illustrates the relationship with some implementation methods. Figure 1 A battery pack used in conjunction with power tools.

[0034] Figure 4 The following are illustrated according to some embodiments. Figure 3 A block diagram of the control system for the battery pack.

[0035] Figure 5 A rotor comprising a spoked magnet construction according to some embodiments is shown.

[0036] Figure 6 A rotor comprising a spoked magnet construction according to some embodiments is shown.

[0037] Figure 7 A rotor comprising a spoked magnet construction according to some embodiments is shown.

[0038] Figure 8 A rotor comprising a spoked magnet construction according to some embodiments is shown.

[0039] Figure 9 A rotor comprising a spoked magnet construction according to some embodiments is shown.

[0040] Figure 10 A rotor comprising a spoked magnet construction according to some embodiments is shown.

[0041] Figure 11A-11BA rotor comprising a spoked magnet construction according to some embodiments is shown.

[0042] Figure 12 A rotor comprising a spoked magnet construction according to some embodiments is shown.

[0043] Figure 13A and 13B A rotor comprising a spoked magnet construction according to some embodiments is shown.

[0044] Figures 14A-14B A rotor comprising a spoked magnet construction according to some embodiments is shown.

[0045] Figure 15 An unfolded view of a motor rotor including a spoked magnet structure according to some embodiments is shown. Detailed Implementation

[0046] Figure 1 A power tool 100 including a permanent magnet motor is shown. 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, rechargeable power tool battery pack (also referred to as a battery pack). Although... Figure 1 A hammer drill is shown, but in some embodiments, the components described herein are incorporated into other types of power tools, including drill drives, impact drives, impact wrenches, angle grinders, circular saws, reciprocating saws, plate compactors, core drills, wire trimmers, leaf blowers, vacuum cleaners, etc. In permanent magnet motor power tools such as power tool 100, switching elements are selectively enabled and disabled by control signals from a controller to selectively apply power from a power source (e.g., a battery pack) to drive the permanent magnet motor.

[0047] 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 controller 202 is electrically connected to a motor 204, a battery interface 206, a trigger switch 208 (connected to 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 FET switching module 220 (e.g., including 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 a combination of hardware and software operable 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), etc.

[0048] The controller 202 includes a plurality of electrical and electronic components that provide power, operation control, and protection to components and modules within the controller 202 and / or the power tool 100. For example, the controller 202 particularly includes a processing unit 226 (e.g., a microprocessor, microcontroller, electronic controller, electronic processor, or other suitable programmable device), a memory 228, an input unit 230, and an output unit 232. The processing unit 226 particularly includes a control unit 234, an arithmetic logic unit (“ALU”) 236, and a plurality of 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, the memory 228, the input unit 230, and the output unit 232, as well as 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 illustrative purposes, Figure 2 The diagram generally illustrates the control and / or data bus. In view of the inventive features 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.

[0049] Memory 228 is a non-transitory computer-readable medium, including, for example, a program storage area and a data storage area. The program storage area and data storage area may include combinations 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 in RAM of memory 228 (e.g., during execution), ROM of memory 228 (e.g., on a substantially permanent basis), or another non-transitory computer-readable medium (such as another memory or disk). Software included in an implementation of power tool 100 may be stored in memory 228 of controller 202. 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 to retrieve from memory 228 and execute instructions related to the control processes and methods described herein. In other configurations, controller 202 includes additional, fewer, or different components.

[0050] Battery pack interface 206 includes a combination of mechanical components (e.g., rails, recesses, latches, etc.) and electrical components (e.g., one or more terminals) configured and operable for mating with a battery pack (e.g., mechanical, electrical, and communicative connection). For example, it is provided by battery pack 300 (see...). Figure 3 Power supplied to the power tool 100 is provided to the power input module 218 via the battery pack interface 206. The power input module 218 includes a combination of active and passive components to regulate or control the power received from the battery pack 300 before supplying power to the controller 202. The battery pack interface 206 also supplies power to the FET switching module 220 to selectively supply power to the motor 204 by switching the FET. 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.

[0051] 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 can be configured to display the status of power tool 100 or information associated with power tool 100. For example, indicator 214 is configured to indicate measured electrical characteristics of power tool 100, the status of power tool, the status of motor 204, etc. User input module 216 is operatively coupled to controller 202 to, for example, select forward or reverse operating modes, torque and / or speed settings for power tool 100 (e.g., 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 required to achieve a desired operating level of power tool 100, such as one or more knobs, one or more dials, one or more switches, one or more buttons, etc.

[0052] 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.

[0053] Figure 4 A control system for a battery pack 300 is shown. 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 controller 400 shown is connected to one or more battery cells 402 and an interface 404 (e.g., Figure 3 The interface portion 304 of the battery pack 300 is shown. 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 operable to control the operation of the battery pack 300, monitor the status of the battery pack 300, enable or disable the charging of the battery pack 300, enable or disable the discharging of the battery pack 300, etc.

[0054] The controller 400 includes a plurality of electrical and electronic components that provide power, operational control, and protection to components and modules within the controller 400 and / or battery pack 300. For example, the controller 400 particularly includes a processing unit 412 (e.g., a microprocessor, microcontroller, electronic processor, electronic controller, or other suitable programmable device), a memory 414, an input unit 416, and an output unit 418. The processing unit 412 particularly includes 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, memory 414, input unit 416, and output unit 418, as well as 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 illustrative purposes, Figure 4 The diagram generally illustrates the control and / or data bus. Given the inventive features 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.

[0055] Memory 414 is a non-transitory computer-readable medium, including, for example, a program storage area and a data storage area. The program storage area and data storage area may include combinations 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 in RAM of memory 414 (e.g., during execution), ROM of memory 414 (e.g., on a substantially permanent basis), or another non-transitory 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. 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 from memory 414 and execute instructions related to the control processes and methods described herein. In other configurations, controller 400 includes additional, fewer, or different components.

[0056] Interface 404 includes a combination of mechanical components (e.g., guide 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 another device (e.g., a power tool, a battery charger, etc.). For example, interface 404 is configured to communicatively connect to controller 400 via communication line 428.

[0057] Figure 5 A motor 500 for use in a power tool 100 is shown. 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 referred to as 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 slot 520 includes a magnet housing portion 525 configured to receive a magnet 530. The magnet may be made of neodymium, ferrite, or other types of magnetic materials. In some embodiments, the magnet 530 may be secured within the magnet housing portion 525 using injection molding, adhesives, or another method of securely mounting the magnet. The magnet housing portion 525 includes a first portion 535 spaced apart from the rotor's rotation center by a first radial distance and a second portion 540 spaced apart from the rotor's rotation center by a second radial distance. 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 exists between the inner ribs 545. The magnet housing portion 525 is configured to receive a magnet 530. The magnet 530 includes a length 555 and a width 560.

[0058] In some embodiments, the length 555 of the magnet 530 is greater than half the width 565 of the stator tooth 570 (also referred to as the stator tooth). In some embodiments, the width 560 of the magnet 530 is determined based on the following equation:

[0059] Equation 1

[0060] For example, the motor may include a rotor diameter of 40 mm, a stator tooth width of 8 mm, and six poles. In this embodiment, the maximum width of the magnet is approximately 16.7 mm.

[0061] Figure 6A motor 600 for use in a power tool 100 is shown. 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 of the slots 620 includes a magnet housing portion 625 configured to receive a magnet 630. The magnet 630 may be made of a material similar to that described above and / or fixed to the magnet housing portion 625 as described above. In the illustrated embodiment, the rotor 615 includes an open-center rotor 635 that receives a motor shaft. The open-center rotor 635 advantageously improves the overall electromagnetic performance of the motor 600 by approximately 5%. The magnet housing portion is configured to receive the magnet 630, which includes a length 640 and a width 645. In some embodiments, the length 640 of the magnet 630 must be greater than half the width 650 of the stator tooth 655. In some embodiments, the width 645 of the magnet 630 can be determined by Equation 1 described above.

[0062] Figure 7 A motor 700 for use in a power tool 100 is shown. 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, and each slot includes a magnet housing portion 725 configured to receive a magnet 730. The magnet 730 may be made of a material similar to that described above, and / or fixed to the magnet housing portion 725 as described above. The magnet housing portion includes a first portion 735 spaced from the rotation center of the rotor 715 by a first radial distance and a second portion 740 spaced from the rotation center of the rotor 715 by a second radial distance. 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 rib 750 is positioned to close a plurality of slots 720. The outer rib includes a length 755 and a width 760. For example, the width 760 of the outer rib can be between 0.1 mm and 1.4 mm. The magnet housing portion is configured to receive a magnet, which includes a length 765 and a width 770. In some embodiments, the length 765 of the magnet 730 must be greater than half the width 775 of the stator tooth 780. In some embodiments, the width 775 of the magnet 730 can be determined by Equation 1 described above.

[0063] Figure 8A motor 800 including a rotor 805 is shown 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 a spoke-type configuration, and each slot includes a magnet housing portion 810. Each magnet housing portion 810 is configured to receive a magnet 815. The magnet 815 may be made of a material similar to that described above, and / or fixed to the magnet housing portion 810 as described above. The magnet 815 includes a length 820 and a width 825. In some embodiments, the length 820 of the magnet 815 must be greater than half the width 860 of the stator teeth 865. In some embodiments, the width 825 of the magnet 815 can be determined by Equation 1 described above.

[0064] In the illustrated embodiment, rotor 805 includes inner ribs 830 configured to connect magnet housing portions 810 to each other via a central barrier 835 (e.g., a central ring or arcuate portion of rotor 805). The inner ribs 830 are alternately spaced between each of a plurality of slots. Positioned between the inner ribs 830 are flux barriers or air space barriers 840. In some cases, there are a plurality of inner ribs and a plurality of air space barriers, and at least one of the air space barriers is positioned between a corresponding inner rib. The magnet housing portion 810 exposes the air space barriers 840 on an inner portion of rotor 805, and the magnet housing portion 810 includes outer ribs 845 positioned at an outer portion 850 of rotor 805. The outer ribs 845 include a length 855 and a width 860. For example, the width of the outer ribs 845 can be between 0.1 mm and 1.4 mm. In some embodiments, each of the outer ribs 845 includes a recess 870 formed on the outer circumference of the rotor 805.

[0065] Figure 9 A motor rotor 900 including a spoke-type magnet configuration is shown. The rotor 900 includes a plurality of slots 905 configured in a spoke-type configuration, and each slot 905 includes a magnet housing portion 910 configured to receive a magnet 915. The magnet 915 may be made of a material similar to that described above, and / or fixed to the magnet housing portion 910 as described above. The magnet 915 includes a length 920 and a width 925. In some embodiments, the length 920 of the magnet 915 must be greater than half the width 960 of the stator teeth 965. In some embodiments, the width 925 of the magnet 915 can be determined by Equation 1 described above.

[0066] In some embodiments, the magnet housing portion 910 includes a magnet retaining portion 930, also referred to as a shoe, positioned on the inner circumference 935 of the magnet housing portion 910. The shoe is configured to assist the magnet housing portion 910 in securely receiving a 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. Additionally, 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 can be between 0.1 mm and 1.4 mm. In some embodiments, the rotor 900 includes an open-center rotor 970, similar to those described above. Figure 6 The open-center rotor 635 is shown.

[0067] Figure 10 A rotor 1000 for use with a power tool 100 is shown. The rotor 1000 includes a spoke-type magnet configuration. The rotor 1000 includes a plurality of slots 1005 configured in a spoke-type configuration, and each slot 1005 includes a magnet housing portion 1010 configured to receive a magnet 1015. The magnet 1015 may be made of a material similar to that described above, and / or fixed to the magnet housing portion 1010 as described above. The magnet 1015 includes a length 1020 and a width 1025. In some embodiments, the length 1020 of the magnet 1015 must be greater than half the width 1070 of the stator teeth 1075. In some embodiments, the width 1025 of the magnet 1015 can be determined by the equation described above. In some embodiments, the magnet housing portion 1010 includes an air gap 1030 positioned on the inner circumference 1035 of the magnet housing portion 1010. An air gap 1030 separates the magnet housing portion from the central circumference 1040 of the rotor 1000. The air gap 1030 includes inner ribs 1045 positioned between two of the magnet housing portions 1010. Additionally, in some embodiments, the magnet housing portion 1010 includes outer ribs 1050. The outer ribs 1050 are positioned on the outer circumference 1055 of the magnet housing portion 1010. The outer ribs 1050 include a length 1060 and a width 1065. For example, the width of the outer ribs 1050 may be between 0.1 mm and 1.4 mm. In some embodiments, the width 1025 of the magnet 1015 can be determined by Equation 1 described above.

[0068] Figure 11A and 11B A rotor 1100 is shown for use with a power tool 100. In some cases, in Figure 11A and Figure 11B The rotor 1100 configured in the middle is compatible with alternative motor configurations (such as those previously in the middle). Figure 10 The text is a jumbled mix of characters and symbols, making it impossible to translate coherently. It appears to be a collection of Figure 10 The rotor 1100 described above has lower magnetic flux leakage compared to the rotor 1000 described above. The rotor 1100 includes a spoke-type magnet configuration. The rotor 1100 includes a plurality of slots 1105 configured in a spoke-type configuration, and each slot includes a magnet housing portion 1110 configured to receive a magnet 1115. The magnet 1115 may be made of a material similar to that described above, and / or fixed to the magnet housing portion 1110 as described above. The magnet 1115 includes a length 1120 and a width 1125. In some embodiments, the length 1120 of the magnet 1115 must be greater than half the width 1190 of the stator tooth 1195. In some embodiments, the width 1125 of the magnet 1115 can be determined by the equation 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. A 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 spans between 0.1 mm and 1.4 mm. The length extends a first longitudinal distance 1150 in the axial direction of the rotor 1100. Additionally, the magnet housing portion 1110 includes a plurality of external air gaps 1155 spaced apart 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, the length 1160 extending a second longitudinal distance 1170 in the axial direction of the rotor 1100. In some embodiments, the external air gap 1155 includes a length and width approximately equal to the length 1160 and width 1165 of each of the plurality of alternating outer rib portions 1130. In some embodiments, the width 1125 of the magnet 1115 can be determined by Equation 1 described above.

[0069] In some embodiments, the magnet housing portion 1110 includes a plurality of internal air gap portions 1175 positioned on the inner circumference 1180 of the magnet housing portion 1110. The plurality of internal air 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 air gap portions 1175 are spaced apart in an arrangement opposite to that of 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 air gap portions 1175, and for a second longitudinal distance 1170, the magnet housing portion 1110 includes the internal air gap portions 1175 but does not include the external rib portions 1130.

[0070] Figure 12A rotor 1200 for use in a power tool 100 is shown. The rotor 1200 includes a spoke-type magnet configuration. The rotor 1200 includes a plurality of slots 1205 configured in a spoke-type configuration, and each slot 1205 includes a magnet housing portion 1210 configured to receive a magnet. The magnet may be made of a material similar to that described above, and / or secured 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 similarly includes an outer rib portion 1225 as described above, and the outer rib portion may span a range between 0.1 mm and 1.4 mm. The magnet housing portion 1210 also includes an inner boot portion 1230 configured to securely retain the magnet. The inner boot portion 1230 includes a first length 1235 and a first width 1240 on each side of the inner boot portion 1230. In some embodiments, the inner boot portion 1230 includes a protrusion 1245 and a recess 1250. In some embodiments, the magnet housing portion 1210 includes a plurality of inner boot portions. For example, in some cases, the magnet housing portion 1210 includes two inner boot portions, each of which is configured on an opposite side of the magnet housing portion, and each of the two inner boot portions is configured to retain a magnet within the magnet housing portion 1210.

[0071] In some embodiments, the rotor 1200 includes an overmolded shaft 1255 on the inner circumference of the rotor 1200. This overmolded material can be, for example, a material injected between the lamination stack portion 1260 of the rotor 1200 and the shaft portion 1265 of the rotor 1200. For example, the material can be one selected from the group consisting of injection-molded plastics, epoxy resins, polyurethanes, silicon steel, composite materials, thermal interface materials, etc. The lamination stack portion 1260 includes a gap 1270 formed between adjacent magnet housing portions 1210. In some embodiments, the gap 1270 is also filled with injected material. In some embodiments, the width 1220 of the magnet for the magnet housing portion 1210 can be determined by Equation 1 described above.

[0072] Figure 13A and 13BA rotor 1300 for use in a power tool 100 is shown. The rotor 1300 includes a spoke-type magnet configuration. The rotor 1300 includes a plurality of slots 1305 configured in a spoke-type configuration, and each slot 1305 includes a magnet housing portion 1310 configured to receive a magnet. The magnet may be made of a material similar to that described above, and / or 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 bootie 1330, as well as an inner rib 1375, similar to those described above. In some embodiments, 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 laminations. For example, in some embodiments, the minimum interference fit 1335 may be no greater than 10 micrometers. In some embodiments, the shaft surface 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 embodiments, the rotor 1300 includes a wrinkled region 1370 located on an inner portion of the rotor 1300, such as Figure 13B As shown. In some cases, the wrinkled area can be configured to compress the inner rib 1375 or deform the inner rib 1375 during the press fit of the shaft. The stacked portion 1380 includes a gap 1385. In some embodiments, the width 1320 of the magnet for the magnet housing portion 1310 can be determined by Equation 1 described above.

[0073] Figure 14A A rotor 1400 for use with a power tool 100 is shown. The rotor 1400 includes a spoke-type magnet configuration. The rotor 1400 includes a plurality of slots 1405 configured in a spoke-type configuration, and each slot 1405 includes a magnet housing portion 1410 configured to receive a magnet. The magnet may be made of a material similar to that described above, and / or 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 portions described above. In some embodiments, the rotor includes a stainless steel ring portion 1415 inside the rotor 1400. In some embodiments, the width of the magnet for the magnet housing portion 1410 can be determined by Equation 1 described above.

[0074] Figure 14B A rotor 1450 for use with a power tool 100 is shown. The rotor 1450 includes a first keyway 1455 positioned on a portion of a lamination stack 1460 of the rotor 1450 and a second keyway 1465 positioned on a portion of a shaft. In some embodiments, the first keyway 1455 and the second keyway 1465 reduce, eliminate, or prevent slippage of the lamination stack 1460.

[0075] Figure 15 A rotor 1500 for use with a power tool 100 is shown. The rotor 1500 includes a plurality of slots 1505 configured in a spoke-like structure, and each slot 1505 includes a magnet housing portion 1510 configured to receive a magnet 1512. The magnet 1512 may be made of a material similar to that described above, and / or 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 bootie 1530, and an inner rib 1575, similar to those described above. The rotor includes a stack of laminations 1535, which includes 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 extending from a first end 1555 of the rotor 1500 through 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 further includes a second bearing 1585 located at the second end 1560 of the rotor, and a plurality of C-rings 1590 configured to couple the second bearing 1585 to the shaft 1550 of the rotor 1500. In some embodiments, the shaft 1550 includes a knurled surface for injection molding purposes.

[0076] Representative characteristics

[0077] Representative features are set forth in the following clauses, which stand alone or may be combined in any combination with one or more features disclosed in the text and / or drawings of this patent specification.

[0078] 1. An electric tool, comprising:

[0079] A battery pack interface configured to receive a removable and rechargeable battery pack; and

[0080] Motors, including:

[0081] The stator includes a plurality of stator teeth configured to receive a plurality of stator coils, and

[0082] Rotor, the rotor comprising:

[0083] A plurality of slots, the plurality of slots being configured in a spoke-like structure, each of the plurality of slots including a magnet housing portion configured to receive a magnet;

[0084] Central barrier;

[0085] A plurality of inner ribs, the plurality of inner ribs being configured to connect at least one of the magnet housing portions of the plurality of slots to the central barrier;

[0086] At least one air space barrier, the at least one air space barrier being located between the plurality of inner ribs.

[0087] At least one of the magnet housing portions of the plurality of slots is exposed to the at least one air space barrier.

[0088] 2. The power tool according to claim 1, wherein the magnet includes a length greater than half the width of one of the plurality of stator teeth.

[0089] 3. The power tool according to any one of the preceding clauses, wherein the magnet includes a magnet width, wherein the magnet width is determined based on the diameter of the rotor, the width of the stator teeth, and the number of poles of the motor.

[0090] 4. The power tool according to any one of the preceding clauses, wherein the rotor further includes an outer rib positioned at the outer circumference of the rotor, the outer rib being configured to retain the first magnet within a first magnet housing portion.

[0091] 5. The power tool according to claim 4, wherein the rotor further includes a second outer rib positioned at the outer circumference of the rotor, the second outer rib being configured to retain the second magnet within a second magnet housing portion.

[0092] 6. The power tool according to clause 4, wherein the outer rib includes a width between about 0.1 mm and 1.4 mm.

[0093] 7. The power tool according to claim 4, wherein the outer rib includes a recess formed on the outer circumference of the rotor.

[0094] 8. An electric tool, comprising:

[0095] A battery pack interface configured to receive a removable and rechargeable battery pack; and

[0096] Motors, including:

[0097] The stator includes a plurality of stator teeth configured to receive a plurality of stator coils, and

[0098] Rotor, the rotor comprising:

[0099] Rotor shaft section;

[0100] Stacked parts;

[0101] A plurality of slots, the plurality of slots being configured in a spoke-like structure, each of the plurality of slots including a magnet housing portion configured to receive a magnet;

[0102] A plurality of outer rib portions are positioned on the outer circumference of the magnet housing portion, wherein each of the plurality of outer rib portions includes a first length extending a first distance in the axial direction of the rotor;

[0103] A plurality of inner boot portions, the plurality of inner boot portions being located on the magnet housing portion, each of the plurality of inner boot portions including a protrusion and a recess; and

[0104] An overmolded component comprising material injected between the laminated stack portion and the rotor shaft portion.

[0105] 9. The power tool according to claim 8, wherein the magnet includes a length greater than half the width of one of the plurality of stator teeth.

[0106] 10. The power tool according to any one of clauses 8 or 9, wherein the magnet includes a magnet width, wherein the magnet width is determined based on the diameter of the rotor, the width of the stator teeth, and the number of poles of the motor.

[0107] 11. The power tool according to any one of clauses 8 to 10, wherein each of the plurality of outer rib portions includes a width ranging from about 0.1 mm to 1.4 mm.

[0108] 12. The power tool according to any one of clauses 8 to 11, wherein each of the plurality of inner boot portions includes a first length and a first width.

[0109] 13. The power tool according to any one of clauses 8 to 12, wherein the plurality of inner boot portions are configured to retain the magnet within the magnet housing portion.

[0110] 14. The power tool according to claim 13, wherein the material injected between the stacked portion and the rotor shaft portion is selected from the group consisting of injection-molded plastics, epoxy resins, polyurethanes, silicon steel, composite materials, and thermal interface materials.

[0111] 15. An electric tool, comprising:

[0112] A battery pack interface configured to receive a removable and rechargeable battery pack; and

[0113] A motor, the motor comprising:

[0114] The stator includes a plurality of stator teeth configured to receive a plurality of stator coils, and

[0115] Rotor, the rotor comprising:

[0116] Stacking;

[0117] A plurality of slots, the plurality of slots being configured in a spoke-like structure, each of the plurality of slots including a magnet housing portion configured to receive a magnet.

[0118] A shaft, the shaft including a knurled portion extending a first circumferential distance around the shaft and a smooth portion extending a second circumferential distance around the shaft, and

[0119] A wrinkled region, located on the inner portion of the rotor, is configured to deform the inner ribs of the rotor.

[0120] 16. The power tool according to claim 15, wherein the magnet includes a length greater than half the width of one of the plurality of stator teeth.

[0121] 17. The power tool according to any one of clauses 15 or 16, wherein the magnet includes a magnet width, wherein the magnet width is determined based on the diameter of the rotor, the width of the stator teeth, and the number of poles of the motor.

[0122] 18. The power tool according to any one of clauses 15 to 17, wherein the rotor further includes a minimum interference fit between the outer circumference of the shaft and the inner circumference of the stack of laminations, the minimum interference fit being less than or equal to 10 micrometers.

[0123] 19. The power tool according to any one of clauses 15 to 18, wherein the wrinkled area is further configured to deform the inner rib during press fitting.

[0124] 20. The power tool according to any one of claims 15 to 19, wherein the rotor further includes a first keyway positioned on a first portion of the lamination stack and a second keyway positioned on a second portion of the shaft, the first keyway and the second keyway being configured to prevent slippage of the lamination stack.

[0125] Therefore, the embodiments described in this utility model provide power tools including a spoked motor. Various features and advantages are set forth in the appended 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: The stator includes a plurality of stator teeth configured to receive a plurality of stator coils, and Rotor, the rotor comprising: A plurality of slots, the plurality of slots being configured in a spoke-like structure, each of the plurality of slots including a magnet housing portion configured to receive a magnet; Central barrier; A plurality of inner ribs, the plurality of inner ribs being configured to connect at least one of the magnet housing portions of the plurality of slots to the central barrier; At least one air space barrier, the at least one air space barrier being located between the plurality of inner ribs. At least one of the magnet housing portions of the plurality of slots is exposed to the at least one air space barrier.

2. The power tool as described in claim 1, characterized in that, The magnet includes a length greater than half the width of one of the plurality of stator teeth.

3. The power tool as described in claim 1, characterized in that, The magnet includes a magnet width, wherein the magnet width is determined based on the diameter of the rotor, the width of the stator teeth, and the number of poles of the motor.

4. The power tool as described in claim 1, characterized in that, The rotor further includes an outer rib located at the outer circumference of the rotor, the outer rib being configured to retain the first magnet within a first magnet housing portion.

5. The power tool as described in claim 4, characterized in that, The rotor further includes a second outer rib positioned at the outer circumference of the rotor, the second outer rib being configured to retain the second magnet within a second magnet housing portion.

6. The power tool as described in claim 4, characterized in that, The outer ribs have a width between approximately 0.1 mm and 1.4 mm.

7. The power tool as described in claim 4, characterized in that, The outer rib includes a recess formed on the outer circumference of the rotor.

8. An electric tool, comprising: A battery pack interface configured to receive a removable and rechargeable battery pack; and A motor, the motor comprising: The stator includes a plurality of stator teeth configured to receive a plurality of stator coils, and Rotor, the rotor comprising: Rotor shaft section; Stacked parts; A plurality of slots, the plurality of slots being configured in a spoke-like structure, each of the plurality of slots including a magnet housing portion configured to receive a magnet; A plurality of outer rib portions are located on the outer circumference of the magnet housing portion, wherein each of the plurality of outer rib portions includes a first length extending a first distance in the axial direction of the rotor. A plurality of inner boot portions, each of which is positioned on the magnet housing portion, includes a protrusion and a recess. An overmolded component comprising material injected between the laminated stack portion and the rotor shaft portion.

9. The power tool as claimed in claim 8, characterized in that, The magnet includes a length greater than half the width of one of the plurality of stator teeth.

10. The power tool as claimed in claim 8, characterized in that, The magnet includes a magnet width, wherein the magnet width is determined based on the diameter of the rotor, the width of the stator teeth, and the number of poles of the motor.

11. The power tool as claimed in claim 8, characterized in that, Each of the plurality of outer rib portions includes a width ranging from approximately 0.1 mm to 1.4 mm.

12. The power tool as claimed in claim 8, characterized in that, Each of the plurality of inner boot portions includes a first length and a first width.

13. The power tool as claimed in claim 8, characterized in that, The plurality of inner boot portions are configured to hold the magnet within the magnet housing portion.

14. The power tool as claimed in claim 13, characterized in that, The material injected between the stacked laminations and the rotor shaft is selected from one of the group consisting of injection-molded plastics, epoxy resins, polyurethanes, silicon steel, composite materials, and thermal interface materials.

15. An electric tool, comprising: A battery pack interface configured to receive a removable and rechargeable battery pack; and Motors, including: The stator includes a plurality of stator teeth configured to receive a plurality of stator coils, and Rotor, the rotor comprising: Stacking; A plurality of slots, the plurality of slots being configured in a spoke-like structure, each of the plurality of slots including a magnet housing portion configured to receive a magnet; A shaft, the shaft including a knurled portion extending a first circumferential distance around the shaft and a smooth portion extending a second circumferential distance around the shaft, and A wrinkled region, located on the inner portion of the rotor, is configured to deform the inner ribs of the rotor.

16. The power tool as claimed in claim 15, characterized in that, The magnet includes a length greater than half the width of one of the plurality of stator teeth.

17. The power tool as claimed in claim 15, characterized in that, The magnet includes a magnet width, wherein the magnet width is determined based on the diameter of the rotor, the width of the stator teeth, and the number of poles of the motor.

18. The power tool as claimed in claim 15, characterized in that, The rotor further includes a minimum interference fit between the outer circumference of the shaft and the inner circumference of the stacked laminations, the minimum interference fit being less than or equal to 10 micrometers.

19. The power tool as claimed in claim 15, characterized in that, The wrinkled area is further configured to deform the inner rib during press fitting.

20. The power tool as claimed in claim 15, characterized in that, The rotor further includes a first keyway positioned on a first portion of the lamination stack and a second keyway positioned on a second portion of the shaft, the first keyway and the second keyway being configured to prevent the lamination stack from sliding.

Images