Power tool including switchable delta-WYE motor

Abstract

A power tool including an electric motor including a stator assembly including stator segments connected to each other. Each stator segment includes a core, a first and second electrical contact terminals, and a stator winding including a first contact end connected to the first electrical contact terminal and a second contact end connected to the second electrical contact terminal. The motor further includes a switch housing configured to receive the stator assembly and including pairs of female contact terminals. Each pair being configured to receive the contact terminals of a stator segment. The switch housing and the stator assembly are rotationally movable with respect to one another between a plurality of positions corresponding to different motor configurations. The electric motor further includes a rotor configured to rotate with respect to the stator assembly and the switch housing. The rotor including a rotor core, and a plurality of permanent magnets.

Description

Attorney Docket No. 066042-1957-W001POWER TOOL INCLUDING SWITCHABLE DELTA-WYE MOTORRELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 703,260, filed October 4, 2024, the entire content of which is hereby incorporated by reference.FIELD

[0002] Embodiments described herein relate to motors for use in a power tool and / or outdoor power equipment.SUMMARY

[0003] Electronically commutated motors may be employed in power tools (for example, cordless drills, impact drivers, and the like). Different power tool applications may benefit from different amounts of motor power, different speed profiles, or different torque profiles. These differences can be achieved by modifying a configuration of motor stator windings.Accordingly, it may be beneficial for a motor to be mechanically controlled to change between a plurality of different motor configurations.

[0004] Power tools described herein include a battery pack interface and an electric motor. The battery pack interface is configured to receive a removable and rechargeable battery pack. The electric motor includes a stator assembly including a plurality of stator segments connected to each other. Each stator segment includes a stator core, a first electrical contact terminal, a second electrical contact terminal, and a stator winding received by the stator core and including a first contact end connected to the first electrical contact terminal and a second contact end connected to the second electrical contact terminal. The electric motor also includes a switch housing configured to receive the stator assembly. The switch housing includes a plurality of pairs of female contact terminals. Each pair of female contact terminals is configured to receive the first electrical contact terminal and the second electrical contact terminal of a respective stator segment of the plurality of stator segments. The switch housing and the stator assembly are rotationally movable with respect to one another between a plurality of positions. Each position corresponds to a different motor configuration of a plurality of motor configurations of the electric motor. The electric motor also includes a rotor configured to rotate with respect toAttorney Docket No. 066042-1957-W001 the stator assembly and the switch housing. The rotor includes a rotor core and a plurality of permanent magnets.

[0005] In some aspects, the plurality of motor configurations includes at least two selected from the group consisting of a parallel delta configuration, a parallel wye configuration, a series delta configuration, and a series wye configuration.

[0006] In some aspects, the at least two of the plurality of motor configurations each correspond to a different winding voltage.

[0007] In some aspects, a first configuration of the plurality of motor configurations corresponds to a 20V winding voltage, and a second configuration of the plurality of motor configurations corresponds to a 60V winding voltage.

[0008] In some aspects, the power tool further includes a locking interface configured to lock the stator assembly in a current position within the switch housing.

[0009] In some aspects, the locking interface is a user-actuable switch.

[0010] In some aspects, the locking interface automatically engages in response to the electric motor being operated by a user.

[0011] In some aspects, the first contact end is welded to the first electrical contact terminal and the second contact end is welded to the second electrical contact terminal.

[0012] Electric motors described herein include a stator assembly switchable between a plurality of different motor configurations, the stator assembly including a plurality of stator segments connected to each other, each stator segment including a stator core, a first electrical contact terminal, a second electrical contact terminal, and a stator winding received by the stator core and including a first contact end connected to the first electrical contact terminal and a second contact end connected to the second electrical contact terminal, a switch housing configured to receive the stator assembly, the switch housing including a plurality of pairs of female contact terminals, each pair of female contact terminals being configured to receive the first electrical contact terminal and the second electrical contact terminal of a respective stator segment of the plurality of stator segments, wherein the switch housing and the stator assembly are rotationally movable with respect to one another between a plurality of positions, each position corresponding to a different motor configuration of a plurality of motor configurationsAttorney Docket No. 066042-1957-W001 of the electric motor, and a rotor configured to rotate with respect to the stator assembly and the switch housing, the rotor including: a rotor core, and a plurality of permanent magnets.

[0013] In some aspects, the plurality of motor configurations includes at least two selected from the group consisting of a parallel delta configuration, a parallel wye configuration, a series delta configuration, and a series wye configuration.

[0014] In some aspects, at least two of the plurality of motor configurations each correspond to a different winding voltage.

[0015] In some aspects, a first configuration of the plurality of motor configurations corresponds to a 20V winding voltage, and a second configuration of the plurality of motor configurations corresponds to a 60V winding voltage.

[0016] In some aspects, the electric motor further includes a locking interface configured to lock the stator assembly in a current position within the switch housing.

[0017] In some aspects, the locking interface is a user-actuable switch.

[0018] In some aspects, the locking interface automatically engages in response to the electric motor being operated by a user.

[0019] In some aspects, the first contact end is welded to the first electrical contact terminal and the second contact end is welded to the second electrical contact terminal.

[0020] Methods of changing a motor configuration of an electric motor described herein include operating the electric motor in a first motor configuration according to a first position of a stator assembly of the electric motor within a switch housing, rotating, within the switch housing, the stator assembly from the first position corresponding to the first motor configuration to a second position corresponding to a second motor configuration different from the first motor configuration, the stator assembly including a plurality of stator segments connected to each other, each stator segment including a stator core, a first electrical contact terminal, a second electrical contact terminal, and a stator winding received by the stator core and including a first contact end connected to the first electrical contact terminal and a second contact end connected to the second electrical contact terminal, and operating the electric motor in the second motor configuration according to the second position of the stator assembly within the switch housing, wherein, in the first position, the first electrical contact terminal and the second electrical contactAttorney Docket No. 066042-1957-W001 terminals are received by a first pair of female contact terminals of the switch housing and, in the second position, the first electrical contact terminals and the second electrical contact terminals are received by a second pair of female contact terminals of the switch housing.

[0021] In some aspects, each of the first motor configuration and the second motor configuration includes at least one selected from the group consisting of a parallel delta configuration, a parallel wye configuration, a series delta configuration, and a series wye configuration.

[0022] In some aspects, the rotation of the stator assembly within the switch housing is bidirectional.

[0023] In some aspects, the first motor configuration and the second motor configuration each corresponds to a different winding voltage.

[0024] Before any embodiments are explained in detail, it is to be understood that the embodiments are not limited in application to the details of the configurations and arrangements of components set forth in the following description or illustrated in the accompanying drawings. The embodiments are capable of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof are meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings.

[0025] Unless the context of their usage unambiguously indicates otherwise, 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.” Likewise, 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 usage unambiguously indicates otherwise.Attorney Docket No. 066042-1957-W001

[0026] In addition, it should be understood that embodiments may include hardware, software, and electronic components or modules that, for purposes of discussion, may be illustrated and described as if the majority of the components were implemented solely in hardware. However, one of ordinary skill in the art, and based on a reading of this detailed description, would recognize that, in at least one embodiment, the electronic-based aspects may be implemented in software (e.g., stored on non-transitory computer-readable medium) executable by one or more processing units, such as a microprocessor and / or application specific integrated circuits (“ASICs”). As such, it should be noted that a plurality of hardware and software based devices, as well as a plurality of different structural components, may be utilized to implement the embodiments. For example, “servers,” “computing devices,” “controllers,” “processors,” etc., described in the specification can include one or more processing units, one or more computer-readable medium modules, one or more input / output interfaces, and various connections (e.g., a system bus) connecting the components.

[0027] Relative terminology, such as, for example, “about,” “approximately,” “substantially,” etc., used in connection with a quantity or condition would be understood by those of ordinary skill to be inclusive of the stated value and has the meaning dictated by the context (e.g., the term includes at least the degree of error associated with the measurement accuracy, tolerances [e.g., manufacturing, assembly, use, etc.] associated with the particular value, etc.). Such terminology should also be considered as disclosing the range defined by the absolute values of the two endpoints. For example, the expression “from about 2 to about 4” also discloses the range “from 2 to 4”. The relative terminology may refer to plus or minus a percentage (e.g., 1%, 5%, 10%) of an indicated value.

[0028] It should be understood that although certain drawings illustrate hardware and software located within particular devices, these depictions are for illustrative purposes only. Functionality described herein as being performed by one component may be performed by multiple components in a distributed manner. Likewise, functionality performed by multiple components may be consolidated and performed by a single component. In some embodiments, the illustrated components may be combined or divided into separate software, firmware and / or hardware. For example, instead of being located within and performed by a single electronic processor, logic and processing may be distributed among multiple electronic processors. Regardless of how they are combined or divided, hardware and software components may beAttorney Docket No. 066042-1957-W001 located on the same computing device or may be distributed among different computing devices connected by one or more networks or other suitable communication links. Similarly, a component described as performing particular functionality may also perform additional functionality not described herein. For example, a device or structure that is “configured” in a certain way is configured in at least that way but may also be configured in ways that are not explicitly listed.

[0029] Accordingly, in the claims, if an apparatus, method, or system is claimed, for example, as including a controller, control unit, electronic processor, computing device, logic element, module, memory module, communication channel or network, or other element configured in a certain manner, for example, to perform multiple functions, the claim or claim element should be interpreted as meaning one or more of such elements where any one of the one or more elements is configured as claimed, for example, to make any one or more of the recited multiple functions, such that the one or more elements, as a set, perform the multiple functions collectively.

[0030] Other aspects of the embodiments will become apparent by consideration of the detailed description and accompanying drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG. 1 A illustrates a perspective view of a power tool, according to some embodiments.

[0032] FIG. IB illustrates a top-down perspective view of a stator rotation interface and stator locking interface of the power tool of FIG. 1A, according to some embodiments.

[0033] FIG. 2 illustrates a block diagram of a control system of the power tool of FIG. 1A, according to some embodiments.

[0034] FIG. 3 illustrates a battery pack for use with the power tool of FIG. 1 A, according to some embodiments.

[0035] FIG. 4 illustrates a block diagram of a control system of the battery pack of FIG. 3, according to some embodiments.

[0036] FIG. 5A illustrates a stator assembly and a switch housing of an electric motor of the power tool of FIG. 1A, according to some embodiments.Attorney Docket No. 066042-1957-W001

[0037] FIG. 5B illustrates a partial side view of the stator assembly and switch housing of FIG. 5A, according to some embodiments.

[0038] FIG. 6 illustrates a perspective view of the stator assembly of FIG. 5 A, according to some embodiments.

[0039] FIG. 7 illustrates a perspective view of a stator segment of the stator assembly of FIG. 6, according to some embodiments.

[0040] FIG. 8 illustrates a perspective view of the switch housing of FIG. 5 A, according to some embodiments.

[0041] FIG. 9A illustrates a perspective view of a female contact terminal of the switch housing of FIG. 8, according to some embodiments.

[0042] FIG. 9B illustrates a perspective view of a female contact terminal of the switch housing of FIG. 8, according to some embodiments.

[0043] FIG. 10 illustrates a section of the switch housing of FIG. 8, according to some embodiments.

[0044] FIG. 11 A illustrates a stator wiring diagram for a first motor configuration according to a first relative position of the stator assembly of FIG. 6, according to some embodiments.

[0045] FIG. 1 IB illustrates a schematic diagram corresponding to the motor configuration of FIG. HA, according to some embodiments.

[0046] FIG. 12A illustrates a stator wiring diagram for a second motor configuration according to a second relative position of the stator assembly of FIG. 6, according to some embodiments.

[0047] FIG. 12B illustrates a schematic diagram corresponding to the motor configuration of FIG. 12A, according to some embodiments.

[0048] FIG. 13 A illustrates a stator wiring diagram for a third motor configuration according to a third relative position of the stator assembly of FIG. 6, according to some embodiments.

[0049] FIG. 13B illustrates a schematic diagram corresponding to the motor configuration of FIG. 13 A, according to some embodiments.Attorney Docket No. 066042-1957-W001

[0050] FIG. 14A illustrates a stator wiring diagram for a fourth motor configuration according to a fourth relative position of the stator assembly of FIG. 6, according to some embodiments.

[0051] FIG. 14B illustrates a schematic diagram corresponding to the motor configuration of FIG. 14A, according to some embodiments.

[0052] FIG. 15 illustrates a position detection system for the stator assembly of FIG. 6, according to some embodiments.DETAILED DESCRIPTION

[0053] FIG. 1A illustrates 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 motor housing portion 106. The power tool 100 further includes an output driver 108 (illustrated as a chuck), a trigger 110, and a battery pack interface 112. The battery pack interface 112 is configured to mechanically and electrically connect to or receive a power tool battery pack. Although FIG. 1A illustrates 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, vacuums, and the like. In a permanent magnet motor power tool, 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 an electric motor (for example, a permanent magnet motor). In some embodiments, the power tool 100 can be any power tool including a permanent magnet motor that is configured to be operated at, for example, 20,000 rotations per minute or less.

[0054] FIG. IB illustrates a top-down perspective view of a stator locking interface 114A and stator rotation interface 114B of the power tool 100, according to some embodiments. In some embodiments, the stator locking interface 114A and the stator rotation interface 114B are positioned on a top surface of the power tool 100. In other embodiments, the stator locking interface 114A and the stator rotation interface 114B are positioned at another location on the power tool 100. The stator rotation interface 114B is configured to allow a user of the power tool 100 to change a rotational position of a stator assembly to change the motor configuration ofAttorney Docket No. 066042-1957-W001 an electric motor. In some embodiments, operation of the stator rotation interface 114B causes a purely mechanical rotation of the stator assembly. For example, the stator rotation interface 114B may be connected to the stator assembly (e.g., separate from the housing 102 of the power tool) such that a user is able to actuate the stator rotation interface 114B to directly rotate the stator assembly 600 (e.g., move the stator rotation interface 114B left or right in FIG. IB). In some embodiments, operation of the stator rotation interface 114B causes the stator assembly 600 to be rotated into a particular position electronically. For example, in some embodiments the controller 202 is configured to, in response to detecting an operation of the stator rotation interface 114B, rotate the stator assembly (for example, via a separate motor). In other embodiments, the stator rotation interface 114B is configured to rotate a component other than the stator, such as a switch housing that is adjacent to the stator. In such embodiments, the switch housing is configured to be rotated relative to the stator in order to change electrical connections between the windings of the stator. In any of the embodiments, the stator and the switch housing are configured for relative movement with respect to one another in order to control the configuration of the stator windings.

[0055] The stator locking interface 114A is configured to mechanically secure or lock the stator assembly into its current rotational position. For example, in the illustrated embodiment, the stator locking interface 114A is a switch that can be moved between a stator lock position and a stator unlock position (e.g., the stator locking interface 114A can be moved up and down in FIG. IB). In some embodiments, the stator locking interface 114A is a user-actuable locking mechanism. In some embodiments, the stator locking interface 114A is electronically controlled (for example, by a controller 202 [see FIG. 2]). For example, in some embodiments, the controller 202 is configured to automatically lock the stator assembly 600 in place in response to detecting a user operation of the power tool 100. In some embodiments, the movement of the stator locking interface 114A is perpendicular to the movement of the stator rotation interface 114B.

[0056] Switching motor configurations by physically changing the rotational position of the stator assembly 600 (as opposed to a solely electrical circuit approach) may be advantageous as fewer switching components (for example, FETs) are required and power losses and component costs are reduced. Furthermore, such a configuration may enable more efficient transitions between configurations of different winding voltages (for example, 20V and 60V).Attorney Docket No. 066042-1957-W001

[0057] FIG. 2 illustrates a control system 200 for the power tool 100. The control system 200 includes a controller 202. The controller 202 is electrically and / or communicatively connected to a variety of modules or components of the power tool 100. For example, the illustrated controller 202 is electrically connected to a motor 204, a battery pack interface 206, a trigger switch 208 (connected to a trigger 210), one or more sensors or sensing circuits 212, one or more indicators 214, a user input module 216, a power input module 218, an inverter bridge or FET switching module 220 (e.g., including a plurality of switching FETs), and gate drivers 224 for driving the FET switching module 220. In some embodiments, motor 204 is a permanent magnet motor. The controller 202 includes combinations of hardware and software that are operable to, among other things, control the operation of the power tool 100, monitor the operation of the power tool 100, activate the one or more indicators 214 (e.g., an LED), etc.

[0058] The controller 202 includes a plurality of electrical and electronic components that provide power, operational control, and protection to the components and modules within the controller 202 and / or the power tool 100. For example, the controller 202 includes, among other things, a processing unit 226 (e.g., a microprocessor, a microcontroller, an electronic controller, an electronic processor, or another suitable programmable device), a memory 228, input units 230, and output units 232. The processing unit 226 includes, among other things, a control unit 234, an arithmetic logic unit (“ALU”) 236, and a plurality of registers 238, and is implemented using a known computer architecture (e.g., a modified Harvard architecture, a von Neumann architecture, etc.). The processing unit 226, the memory 228, the input units 230, and the output units 232, as well as the various modules or circuits connected to the controller 202 are connected by one or more control and / or data buses (e.g., common bus 240). The control and / or data buses are shown generally in FIG. 2 for illustrative purposes. The use of one or more control and / or data buses for the interconnection between and communication among the various modules, circuits, and components would be known to a person skilled in the art in view of the embodiments described herein.

[0059] The memory 228 is a non-transitory computer readable medium and includes, for example, a program storage area and a data storage area. The program storage area and the data storage area can include combinations of different types of memory, such as a ROM, a RAM (e.g., DRAM, SDRAM, etc ), EEPROM, flash memory, a hard disk, an SD card, or other suitable magnetic, optical, physical, or electronic memory devices. The processing unit 226 is connectedAttorney Docket No. 066042-1957-W001 to the memory 228 and executes software instructions that are capable of being stored in a RAM of the memory 228 (e.g., during execution), a ROM of the memory 228 (e.g., on a generally permanent basis), or another non-transitory computer readable medium such as another memory or a disc. Software included in the implementation of the power tool 100 can be stored in the memory 228 of the controller 202. The software includes, for example, firmware, one or more applications, program data, filters, rules, one or more program modules, and other executable instructions. The controller 202 is configured to retrieve from the memory 228 and execute, among other things, instructions related to the control processes and methods described herein. In other constructions, the controller 202 includes additional, fewer, or different components.

[0060] 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 to and operable for interfacing (e.g., mechanically, electrically, and communicatively connecting) with a battery pack. For example, power provided by a battery pack 300 (see FIG. 3) to the power tool 100 is provided through the battery pack interface 206 to the power input module 218. The power input module 218 includes combinations of active and passive components to regulate or control the power received from the battery pack 300 prior to power being provided to the controller 202. The battery pack interface 206 also supplies power to the FET switching module 220 to be switched by the switching FETs to selectively provide power to the motor 204. The battery pack interface 206 also includes, for example, a communication line 242 for providing a communication line or link between the controller 202 and the battery pack 300.

[0061] The sensor circuits 212 include one or more current sensors, one or more speed sensors, one or more Hall effect sensors, one or more temperature sensors, etc. The indicators 214 include, for example, one or more light-emitting diodes (“LEDs”). The indicators 214 can be configured to display conditions of, or information associated with, the power tool 100. For example, the indicators 214 are configured to indicate measured electrical characteristics of the power tool 100, the status of the power tool, the status of the motor 204, etc. The user input module 216 is operably coupled to the controller 202 to, for example, select a forward mode of operation or a reverse mode of operation, a torque and / or speed setting for the power tool 100 (e.g., using torque and / or speed switches), etc. In some embodiments, the user input module 216 includes a combination of digital and analog input or output devices required to achieve a desiredAttorney Docket No. 066042-1957-W001 level of operation for the power tool 100, such as one or more knobs, one or more dials, one or more switches, one or more buttons, etc. In some embodiments, the user input module 216 includes the stator locking interface 114A and the stator rotation interface 114B.

[0062] FIG. 3 illustrates a 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.

[0063] FIG. 4 illustrates 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 a variety of modules or components of the battery pack 300. For example, the illustrated controller 400 is connected to one or more battery cells 402 and an interface 404 (e.g., the interface portion 304 of the battery pack 300 illustrated in FIG. 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 combinations of hardware and software that are operable to, among other things, control the operation of the battery pack 300, monitor a condition of the battery pack 300, enable or disable charging of the battery pack 300, enable or disable discharging of the battery pack 300, etc.

[0064] The controller 400 includes a plurality of electrical and electronic components that provide power, operational control, and protection to the components and modules within the controller 400 and / or the battery pack 300. For example, the controller 400 includes, among other things, a processing unit 412 (e.g., a microprocessor, a microcontroller, an electronic processor, an electronic controller, or another suitable programmable device), a memory 414, input units 416, and output units 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 units 416, and the output units 418, as well as the various modules or circuits connected to the controller 400 are connected by one or more control and / or data buses (e.g., common bus 426). The control and / or data buses are shown generally in FIG. 4 for illustrative purposes. The use of one or more control and / or data buses for the interconnection between and communication among the variousAttorney Docket No. 066042-1957-W001 modules, circuits, and components would be known to a person skilled in the art in view of the embodiments described herein.

[0065] The memory 414 is a non-transitory computer readable medium and includes, for example, a program storage area and a data storage area. The program storage area and the data storage area can include combinations of different types of memory, such as a ROM, a RAM (e.g., DRAM, SDRAM, etc ), EEPROM, flash memory, a hard disk, an SD card, or other suitable magnetic, optical, physical, or electronic memory devices. The processing unit 412 is connected to the memory 414 and executes software instructions that are capable of being stored in a RAM of the memory 414 (e.g., during execution), a ROM of the memory 414 (e.g., on a generally permanent basis), or another non-transitory computer readable medium such as another memory or a disc. Software included in the implementation of the battery pack 300 can be stored in the memory 414 of the controller 400. The software includes, for example, firmware, one or more applications, program data, filters, rules, one or more program modules, and other executable instructions. The controller 400 is configured to retrieve from the memory 414 and execute, among other things, instructions related to the control processes and methods described herein. In other constructions, the controller 400 includes additional, fewer, or different components.

[0066] The interface 404 includes a combination of mechanical components (e.g., rails, grooves, latches, etc.) and electrical components (e.g., one or more terminals) configured to and operable for interfacing (e.g., mechanically, electrically, and communicatively connecting) the battery pack 300 with another device (e.g., a power tool, a battery pack charger, etc.). For example, the interface 404 is configured to communicatively connect to the controller 400 via a communications line 428.

[0067] FIG. 5 A illustrates an electric motor 500 for use in the power tool 100. The electric motor 500 includes a stator assembly 600, which includes a plurality of stator core elements / segments 700, and a switch housing 800 configured to receive the stator assembly 600. As explained in more detail below, the stator assembly 600 is rotationally movable between a plurality of positions within the switch housing 800. Each rotational position of the stator assembly 600 (with respect to the switch housing 800) corresponds to a different motor configuration of a plurality of motor configurations of the electric motor 500. It should be understood that, although the embodiments and examples described below are with respect to theAttorney Docket No. 066042-1957-W001 stator assembly 600 being rotatable while the switch housing 800 is fixed in position, that, in some embodiments, the switch housing 800 is rotatable and the stator assembly 600 is fixed in position with respect to the switch housing 800.

[0068] FIG. 5B illustrates a partial side view of the electric motor 500. In the illustrated example, the stator segments 700 of the stator assembly 600 form one or more grooves 502A and 502B when assembled (e.g., welded) together. The one or more grooves 502A, 502B each receive an inner feature (for example, of the housing 102), allowing rotation of the stator assembly 600 with respect to the switch housing 800. In some embodiments, a seal (for example, a rubber seal) may be positioned in a space 504 between the stator assembly 600 and the switch housing 800.

[0069] FIG. 6 illustrates the stator assembly 600 without the switch housing 800. The stator assembly 600, as described above, includes the plurality of stator segments 700 connected (for example, welded) to each other to form the stator assembly 600. As illustrated in FIG. 7, each stator segment 700 includes a first and a second electrical contact terminal 702A and 702B, a stator core 704, and a stator winding 706 received by the stator core 704. In some embodiments, the stator core 704 is made of steel (e.g., steel laminations). In other embodiments, the stator core 704 is made of a soft magnetic composite (“SMC”) material. For each stator segment 700, a first contact end of the stator winding 706 is connected to the first electrical contact terminal 702A and a second contact end of the stator winding 706 is connected to the second electrical contact terminal 702B. Both the contact ends of the stator winding 706 are connected (e.g., welded) directly to the respective contact terminal 702A and 702B.

[0070] The stator segments 700 are configured to be connected together (e g., welded) to form a surface that is radially aligned with a rotor positioned within the stator assembly 600. The rotor is configured to rotate along a rotational axis and with respect to the plurality of stator segments 700 and stator assembly 600. The rotor includes a rotor core and a plurality of permanent magnets. The plurality of permanent magnets are fastened or secured (e.g., adhered) to the rotor. As illustrated in FIG. 6, the contact terminals (collectively referred to herein as contact terminals 702) extend from a first end of the stator assembly 600.

[0071] FIG. 8 illustrates the switch housing 800. The switch housing 800 includes a housing 802 supporting a plurality of pairs of female contact terminals 900. As illustrated in FIGS. 9AAttorney Docket No. 066042-1957-W001 and 9B, each female contact terminal 900 includes a stator contact terminal 902 for receiving a respective contact terminal 702 of the stator assembly 600. The female contact terminal 900 is configured to electrically connect with the respective contact terminal 702 of the stator assembly 600 when a contact terminal 702 is positioned within the stator contact terminal 902. The stator contact terminal 902 includes open ends on both sides that allow for bidirectional rotation of the stator assembly 600 (and thus, movement of the contact terminal 702) relative to the switch housing 800.

[0072] The female contact terminals 900 also include a rear contact terminal 904 (electrically coupled to the stator contact terminal 902) for receiving one or more configuration wires (for example, the configuration wire 1002 as illustrated in FIG. 10). Each of the configuration wires 1002 are electrically coupled to and configured to provide power sourced from the FET switching module 220 to the respective stator contact terminal 902 (and, thus, any contact terminal 702 presently in electrical contact with the respective stator contact terminal 902) depending on the position of the stator assembly 600 within the switch housing 800. One or more configuration wires may additionally be connected to one or more other rear contact terminals 904 of one or more other female contact terminals 900.

[0073] As previously described above, the operation of the electric motor 500 changes depending on the position of the stator assembly 600 relative to the switch housing 800. As the stator assembly 600 (or alternatively, in some embodiments, the switch housing 800) is rotated, each of the contact terminals 702 are received by a respective female contact terminal 900 (i.e., the respective stator contact terminal 902), connecting one or more of the stator windings 706 to a particular phase line output by the FET switching module 220 via the respective rear contact terminal 904 and connection wires (for example, wire 1002). Accordingly, the electrical connections of the stator windings 706 of the stator assembly 600 (i.e. the resulting stator wiring circuit) are changed depending on the particular position of the stator assembly 600 (thus changing the operation mode of the electric motor 500). In some embodiments, the winding voltage between motor operations differs. For example, in some embodiments a first configuration of the plurality of motor configurations corresponds to a 20V winding voltage and a second configuration of the plurality of motor configurations corresponds to a 60V winding voltage.Attorney Docket No. 066042-1957-W001

[0074] FIGS. 11 A, 12A, 13 A, and 14A each illustrate a different motor configuration of the electric motor 500 according to different positions of the stator assembly 600 relative to the switch housing 800. The embodiments described below are with respect to the example stator assembly 600 of FIG. 6. The stator assembly 600 of FIG. 6 includes twelve stator segments 700 (and, thus, twenty -four contact terminals 702) and a 15° stator rotation. Such a configuration of the stator assembly 600 allows for the motor 500 to operate at least two of the four motor configurations illustrated in FIGS. 11A, 12A, 13A, and 14A below. It should be understood, however, that, in some embodiments, the stator assembly 600 includes a different number of stator segments 700. A greater number of stator segments 700 allows for a greater number of selectable motor configurations of the motor 500. For example, in embodiments where the stator assembly 600 includes eighteen stator segments 700 (thus, thirty-six contacts) and a 10° stator rotation, the motor 500 is configured to operate in any three of the four motor configurations illustrated in FIGS. 11A, 12A, 13A, and 14A. In each of the examples illustrated in FIGS. 11A, 12 A, 13 A, and 14A, each of the connections 10A-10G correspond to a respective configuration wire of the switch housing 800, three of which (connections 10A - 10C) are each connected to a respective motor power phase supply 9A-0C provided from battery pack interface 206 through the FET switching module 220 (see FIG. 2).

[0075] FIG. 11 A illustrates a first motor configuration 1100A of the stator assembly 600. In the illustrated example, the stator assembly 600 is configured to operate in a parallel delta 18V mode. A corresponding stator winding schematic diagram 1100B is illustrated in FIG. 1 IB.

[0076] FIG. 12A illustrates a second motor configuration 1200A of the stator assembly 600. In the illustrated example, the stator assembly 600 is configured to operate in a parallel wye 31V mode. A corresponding stator winding schematic diagram 1200B is illustrated in FIG. 12B.

[0077] FIG. 13A illustrates a third motor configuration 1300A of the stator assembly 600. In the illustrated example, the stator assembly 600 is configured to operate in a series delta 36V mode. A corresponding stator winding schematic diagram 1300B is illustrated in FIG. 13B.

[0078] FIG. 14A illustrates a fourth motor configuration 1400A of the stator assembly 600. In the illustrated example, the stator assembly 600 is configured to operate in a series wye 62V mode. A corresponding stator winding schematic diagram 1400B is illustrated in FIG. 14B.Attorney Docket No. 066042-1957-W001

[0079] In some embodiments, the power tool 100 includes a stator position sensor 1502, as illustrated in FIG. 15. In the illustrated embodiment, the stator position sensor 1502 includes non-contact sensors 1504A and 1504B (e.g., Hall effect sensors, optical sensors, etc.) and one or more magnets 1506 attached to the stator assembly 600. The controller 202 is configured to receive signals from the sensors 1504A and 1504B and determine, based on the signals, a rotational position of the stator assembly 600 relative to the switch housing 800. Based on the determined rotational position, the controller 202 may further determine a current motor configuration of the electric motor 500. The controller 202 may use this information, for example, to adjust an operation of the FET switching module 220 and / or the gate drivers 224. As another example, the controller 202 may be configured to provide an indication (for example, via the indicators] 214) as to which motor configuration the motor 500 currently is in. As yet another example, the controller 202 may be configured to automatically engage the stator assembly 600 (or, alternatively, the switch housing 800) in a particular rotational position (for example, in response to detecting the measured rotational position corresponds to a predetermined threshold) to lock the stator assembly 600 in position. In such embodiments, the controller 202 may be configured to automatically actuate the stator locking interface 114A (see FIG. IB).REPRESENTATIVE FEATURES

[0080] Representative features are set out 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 the specification.Clause 1. A power tool comprising: an electric motor including: a stator assembly including a plurality of stator segments connected to each other, each stator segment including a stator core, a first electrical contact terminal, a second electrical contact terminal, and a stator winding received by the stator core and including a first contact end connected to the first electrical contact terminal and a second contact end connected to the second electrical contact terminal, a switch housing configured to receive the stator assembly, the switch housing including a plurality of pairs of female contact terminals, each pair of female contact terminals being configured to receive the first electrical contact terminal and the second electrical contact terminal of a respective stator segment of the plurality of stator segments, wherein the switchAttorney Docket No. 066042-1957-W001 housing and the stator assembly are rotationally movable with respect to one another between a plurality of positions, each position corresponding to a different motor configuration of a plurality of motor configurations of the electric motor, and a rotor configured to rotate with respect to the stator assembly and the switch housing, the rotor including: a rotor core, and a plurality of permanent magnets.Clause 2. The power tool of clause 1, wherein the plurality of motor configurations includes at least two selected from the group consisting of a parallel delta configuration, a parallel wye configuration, a series delta configuration, and a series wye configuration.Clause 3. The power tool of any preceding clause, wherein at least two of the plurality of motor configurations each correspond to a different winding voltage.Clause 4. The power tool of clause 3, wherein: a first configuration of the plurality of motor configurations corresponds to a 20V winding voltage; and a second configuration of the plurality of motor configurations corresponds to a 60V winding voltage.Clause 5. The power tool of any preceding clause, the power tool further comprising a locking interface configured to lock the stator assembly in a current position within the switch housing.Clause 6. The power tool of clause 5, wherein the locking interface is a user-actuable switch.Clause 7. The power tool of clause 5, wherein the locking interface automatically engages in response to the electric motor being operated by a user.Clause 8. The power tool of any preceding clause, wherein the first contact end is welded to the first electrical contact terminal and the second contact end is welded to the second electrical contact terminal.Clause 9. An electric motor comprising: a stator assembly switchable between a plurality of different motor configurations, the stator assembly including a plurality of stator segments connected to each other, each stator segment including: a stator core, a first electrical contact terminal, a second electrical contact terminal, and a stator winding received by the stator core and including a first contact end connected to the first electrical contact terminal and a second contact end connected to the second electrical contact terminal, a switch housing configured to receive the stator assembly, the switch housing including a plurality of pairs of female contact terminals, each pair of female contact terminals being configured to receive the first electricalAttorney Docket No. 066042-1957-W001 contact terminal and the second electrical contact terminal of a respective stator segment of the plurality of stator segments, wherein the switch housing and the stator assembly are rotationally movable with respect to one another between a plurality of positions, each position corresponding to a different motor configuration of a plurality of motor configurations of the electric motor, and a rotor configured to rotate with respect to the stator assembly and the switch housing, the rotor including: a rotor core, and a plurality of permanent magnets.Clause 10. The electric motor of clause 9, wherein the plurality of motor configurations includes at least two selected from the group consisting of a parallel delta configuration, a parallel wye configuration, a series delta configuration, and a series wye configuration.Clause 11. The electric motor of clauses 9 or 10, wherein at least two of the plurality of motor configurations each correspond to a different winding voltage.Clause 12. The electric motor of clause 11, wherein: a first configuration of the plurality of motor configurations corresponds to a 20V winding voltage; and a second configuration of the plurality of motor configurations corresponds to a 60V winding voltage.Clause 13. The electric motor of any of clauses 9 to 12, further comprising a locking interface configured to lock the stator assembly in a current position within the switch housing.Clause 14. The electric motor of clause 13, wherein the locking interface is a user-actuable switch.Clause 15. The electric motor of clause 13, wherein the locking interface automatically engages in response to the electric motor being operated by a user.Clause 16. The electric motor of any of clauses 9 to 15, wherein the first contact end is welded to the first electrical contact terminal and the second contact end is welded to the second electrical contact terminal.Clause 17. A method of changing a motor configuration of an electric motor, the method comprising: operating the electric motor in a first motor configuration according to a first position of a stator assembly of the electric motor within a switch housing; rotating, within the switch housing, the stator assembly from the first position corresponding to the first motor configuration to a second position corresponding to a second motor configuration different from the first motor configuration, the stator assembly including a plurality of stator segmentsAttorney Docket No. 066042-1957-W001 connected to each other, each stator segment including a stator core, a first electrical contact terminal, a second electrical contact terminal, and a stator winding received by the stator core and including a first contact end connected to the first electrical contact terminal and a second contact end connected to the second electrical contact terminal; and operating the electric motor in the second motor configuration according to the second position of the stator assembly within the switch housing, wherein, in the first position, the first electrical contact terminal and the second electrical contact terminal are received by a first pair of female contact terminals of the switch housing and, in the second position, the first electrical contact terminal and the second electrical contact terminal are received by a second pair of female contact terminals of the switch housing.Clause 18. The method of clause 17, wherein each of the first motor configuration and the second motor configuration includes at least one selected from the group consisting of a parallel delta configuration, a parallel wye configuration, a series delta configuration, and a series wye configuration.Clause 19. The method of clauses 17 or 18, wherein the rotation of the stator assembly within the switch housing is bidirectional.Clause 20. The method of any of clause 17 to 19, wherein the first motor configuration and the second motor configuration each corresponds to a different winding voltage.

[0081] Thus, embodiments described herein provide, among other things, power tools including mechanically-switchable motor configurations. Various features and advantages are set forth in the following claims.

Claims

Attorney Docket No. 066042-1957-W001CLAIMSWe claim:

1. A power tool comprising: an electric motor including: a stator assembly including a plurality of stator segments connected to each other, each stator segment including: a stator core, a first electrical contact terminal, a second electrical contact terminal, and a stator winding received by the stator core and including a first contact end connected to the first electrical contact terminal and a second contact end connected to the second electrical contact terminal, a switch housing configured to receive the stator assembly, the switch housing including a plurality of pairs of female contact terminals, each pair of female contact terminals being configured to receive the first electrical contact terminal and the second electrical contact terminal of a respective stator segment of the plurality of stator segments, wherein the switch housing and the stator assembly are rotationally movable with respect to one another between a plurality of positions, each position corresponding to a different motor configuration of a plurality of motor configurations of the electric motor, and a rotor configured to rotate with respect to the stator assembly and the switch housing, the rotor including: a rotor core, and a plurality of permanent magnets.

2. The power tool of claim 1, wherein the plurality of motor configurations includes at least two selected from the group consisting of a parallel delta configuration, a parallel wye configuration, a series delta configuration, and a series wye configuration.

3. The power tool of claim 1, wherein at least two of the plurality of motor configurations each correspond to a different winding voltage.Attorney Docket No. 066042-1957-W0014. The power tool of claim 3, wherein: a first configuration of the plurality of motor configurations corresponds to a 20V winding voltage; and a second configuration of the plurality of motor configurations corresponds to a 60V winding voltage.

5. The power tool of claim 1, the power tool further comprising a locking interface configured to lock the stator assembly in a current position within the switch housing.

6. The power tool of claim 5, wherein the locking interface is a user-actuable switch.

7. The power tool of claim 5, wherein the locking interface automatically engages in response to the electric motor being operated by a user.

8. The power tool of claim 1, wherein the first contact end is welded to the first electrical contact terminal and the second contact end is welded to the second electrical contact terminal.

9. An electric motor comprising: a stator assembly switchable between a plurality of different motor configurations, the stator assembly including a plurality of stator segments connected to each other, each stator segment including: a stator core, a first electrical contact terminal, a second electrical contact terminal, and a stator winding received by the stator core and including a first contact end connected to the first electrical contact terminal and a second contact end connected to the second electrical contact terminal, a switch housing configured to receive the stator assembly, the switch housing including a plurality of pairs of female contact terminals, each pair of female contact terminals being configured to receive the first electrical contact terminal and the second electrical contact terminal of a respective stator segment of the plurality of stator segments, wherein the switchAttorney Docket No. 066042-1957-W001 housing and the stator assembly are rotationally movable with respect to one another between a plurality of positions, each position corresponding to a different motor configuration of a plurality of motor configurations of the electric motor, and a rotor configured to rotate with respect to the stator assembly and the switch housing, the rotor including: a rotor core, and a plurality of permanent magnets.

10. The electric motor of claim 9, wherein the plurality of motor configurations includes at least two selected from the group consisting of a parallel delta configuration, a parallel wye configuration, a series delta configuration, and a series wye configuration.

11. The electric motor of claim 9, wherein at least two of the plurality of motor configurations each correspond to a different winding voltage.

12. The electric motor of claim 11, wherein: a first configuration of the plurality of motor configurations corresponds to a 20V winding voltage; and a second configuration of the plurality of motor configurations corresponds to a 60V winding voltage.

13. The electric motor of claim 9, further comprising a locking interface configured to lock the stator assembly in a current position within the switch housing.

14. The electric motor of claim 13, wherein the locking interface is a user-actuable switch.

15. The electric motor of claim 13, wherein the locking interface automatically engages in response to the electric motor being operated by a user.

16. The electric motor of claim 9, wherein the first contact end is welded to the first electrical contact terminal and the second contact end is welded to the second electrical contact terminal.Attorney Docket No. 066042-1957-W00117. A method of changing a motor configuration of an electric motor, the method comprising: operating the electric motor in a first motor configuration according to a first position of a stator assembly of the electric motor within a switch housing; rotating, within the switch housing, the stator assembly from the first position corresponding to the first motor configuration to a second position corresponding to a second motor configuration different from the first motor configuration, the stator assembly including a plurality of stator segments connected to each other, each stator segment including a stator core, a first electrical contact terminal, a second electrical contact terminal, and a stator winding received by the stator core and including a first contact end connected to the first electrical contact terminal and a second contact end connected to the second electrical contact terminal; and operating the electric motor in the second motor configuration according to the second position of the stator assembly within the switch housing, wherein, in the first position, the first electrical contact terminal and the second electrical contact terminal are received by a first pair of female contact terminals of the switch housing and, in the second position, the first electrical contact terminal and the second electrical contact terminal are received by a second pair of female contact terminals of the switch housing.

18. The method of claim 17, wherein each of the first motor configuration and the second motor configuration includes at least one selected from the group consisting of a parallel delta configuration, a parallel wye configuration, a series delta configuration, and a series wye configuration.

19. The method of claim 17, wherein rotation of the stator assembly within the switch housing is bidirectional.

20. The method of claim 17, wherein the first motor configuration and the second motor configuration each corresponds to a different winding voltage.

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