Electric power shovel and method for manufacturing electric power shovel

Abstract

The present application is used for inhibiting the production cost of an electric working machine. An electric working machine (1) has a first brushless motor (6001) and a controller (9), the first brushless motor (6001) has a first stator (201) and a first rotor (3001), the first stator (201) has a first stator core (211) and a plurality of first coils (241) wound on each tooth of a plurality of tooth portions (21T) of the first stator core (211) respectively; the first rotor (3001) is combined with the first stator (201); the controller (9) excites the tooth portion (21T) to rotate the first rotor (3001) around the rotation axis. In a plane orthogonal to the rotation axis, the shape of the first stator core (3211) is the same as the shape of a second stator core (212) of a second stator (3202) used by a second brushless motor (6002) of another electric working machine (101). The first rotor (3001) can be combined with the second stator (3202). The pole number of the first rotor (33001) is different from the pole number of a second rotor (3002) used by the second brushless motor (6002).

Description

TECHNICAL FIELD

[0001] The present application relates to an electric power tool and a manufacturing method of an electric power tool. BACKGROUND

[0002] In the technical field of electric power tools, an electric power tool having a brushless motor is known, such as Japanese Patent Application Publication No. 2019-180165. The brushless motor has a stator and a rotor, wherein the stator has a stator core and a coil supported to the stator core; the rotor has a rotor core and a permanent magnet supported to the rotor core. SUMMARY

[0003] Depending on the kind of electric power tool, the output characteristics required for the brushless motor differ. In a case where different brushless motors are produced depending on the kind of electric power tool according to the output characteristics required for the brushless motor, the production cost can increase.

[0004] An object of the present application is to suppress (control) the production cost of an electric power tool.

[0005] A first aspect of the present application is an electric power tool,

[0006] having a first brushless motor, a second brushless motor, and a controller, wherein

[0007] the first brushless motor has a first stator and a first rotor,

[0008] the first stator has a first stator core and a plurality of first coils, wherein

[0009] the first stator core has a plurality of first tooth portions;

[0010] the plurality of first coils are respectively wound around each of the plurality of first tooth portions;

[0011] the first rotor is combined with the first stator;

[0012] the second brushless motor has a second stator and a second rotor,

[0013] the second stator is capable of being combined with the first rotor, and has a second stator core and a plurality of second coils, wherein

[0014] the second stator core has a plurality of second tooth portions, and has the same shape as the first stator core in a plane orthogonal to the rotational axis;

[0015] the plurality of second coils are respectively wound around each of the plurality of second tooth portions;

[0016] The second rotor is combined with the second stator and has a different number of poles than the first rotor.

[0017] The controller excites the first tooth portion to rotate the first rotor about the rotational axis.

[0018] The second method of the present application is a manufacturing method of an electric working machine,

[0019] A first stator core is manufactured by stacking first steel plates,

[0020] A first stator is manufactured by winding a plurality of first coils on a plurality of first tooth portions of the first stator core in a first wiring pattern,

[0021] A first brushless motor is manufactured by combining the first stator and a first rotor having a first number of poles,

[0022] A second stator core is manufactured by stacking second steel plates having the same shape as the first steel plates,

[0023] A second stator is manufactured by winding a plurality of second coils on a plurality of second tooth portions of the second stator core in a second wiring pattern identical to the first wiring pattern,

[0024] A second brushless motor is manufactured by combining the second stator and a second rotor having a second number of poles that can be combined with the first stator,

[0025] A first electric working machine is manufactured using the first brushless motor,

[0026] A second electric working machine is manufactured using the second brushless motor.

[0027] [Effects of the Invention]

[0028] According to the present application, it is possible to suppress (control) the production cost of an electric working machine. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a perspective view of an electric working machine of the first embodiment as viewed from the front.

[0030] Figure 2 is a perspective exploded view of an electric machine of the first embodiment as viewed from the rear.

[0031] Figure 3 is a perspective exploded view of an electric machine of the first embodiment as viewed from the front.

[0032] Figure 4 is a perspective exploded view of a stator and a rotor of the first embodiment as viewed from the rear.

[0033] Figure 5is a perspective exploded view of the stator and the rotor of the first embodiment, viewed from the front.

[0034] Figure 6 is a diagram schematically showing the stator of the first embodiment.

[0035] Figure 7 is a diagram schematically showing the connection state of the coils of the first embodiment.

[0036] Figure 8 is a diagram of the rotor of the first embodiment, viewed from the left side.

[0037] Figure 9 is a diagram of the rotor of the first embodiment, viewed from the front.

[0038] Figure 10 is a diagram of the rotor core of the first embodiment, viewed from the left side.

[0039] Figure 11 is a perspective exploded view of the rotor core and the permanent magnets of the first embodiment, viewed from the back.

[0040] Figure 12 is a perspective exploded view of the rotor core and the permanent magnets of the first embodiment, viewed from the front.

[0041] Figure 13 is a diagram of the rotor core of the first embodiment, viewed from the front.

[0042] Figure 14 is a diagram of the rotor core of the first embodiment, viewed from the back.

[0043] Figure 15 is a sectional view of the first core of the first embodiment.

[0044] Figure 16 is a partially enlarged sectional view of the first core of the first embodiment.

[0045] Figure 17 is a sectional view of the second core of the first embodiment.

[0046] Figure 18 is a partially enlarged sectional view of the second core of the first embodiment.

[0047] Figure 19 is a diagram showing the relationship between the size of the passage of the magnetic flux of the rotor core, the magnetic flux detected by the magnetic sensor, and the rotation angle of the rotor.

[0048] Figure 20 is a perspective view of the rotor of another embodiment of the first embodiment, viewed from the back.

[0049] Figure 21is a perspective view of the electric power working machine of the second embodiment.

[0050] Figure 22 is a perspective view of the rotor of the second embodiment, viewed from the rear.

[0051] Figure 23 is a perspective view of the rotor of the second embodiment, viewed from the front.

[0052] Figure 24 is a perspective view of the rotor core of the second embodiment, viewed from the front.

[0053] Figure 25 is a view of the rotor core of the second embodiment, viewed from the front.

[0054] Figure 26 is a view of the rotor core of the second embodiment, viewed from the rear.

[0055] Figure 27 is a sectional view of the first core of the second embodiment.

[0056] Figure 28 is a sectional view of the first core of the second embodiment, partially enlarged.

[0057] Figure 29 is a sectional view of the second core of the second embodiment.

[0058] Figure 30 is a sectional view of the second core of the second embodiment, partially enlarged.

[0059] Figure 31 is a view schematically showing the relationship between the stator and the rotor of the third embodiment.

[0060] Figure 32 is a view schematically showing the electric power working machine set of the third embodiment.

[0061] Figure 33 is a view showing the relationship between the number of poles of the rotor, the drive current supplied to the coil, and the rotational speed of the output portion of the rotor of the third embodiment.

[0062] Figure 34 is a view showing the relationship between the number of tooth portions of the stator and the number of poles of the rotor that can be combined with the stator of the third embodiment.

[0063] Figure 35 is a view schematically showing the relationship between the stator and the rotor of another embodiment of the third embodiment.

[0064] Figure 36 is a flowchart of the manufacturing method of the electric power working machine set of another embodiment of the third embodiment.

[0065] Figure 37 Fig. 6 is a diagram schematically showing a connection state of a coil of another embodiment of the third embodiment.

[0066] Figure 38 Fig. 6 is a diagram schematically showing a connection state of a coil of another embodiment of the third embodiment.

[0067] Figure 39 Fig. 6 is a diagram schematically showing a connection state of a coil of another embodiment of the third embodiment.

[0068] Figure 40 Fig. 7 is a cross-sectional view partially enlarges a first core of another embodiment.

[0069] Figure 41 Fig. 8 is a cross-sectional view partially enlarges a second core of another embodiment. DETAILED DESCRIPTION

[0070] Hereinafter, an embodiment of the present application will be described with reference to the drawings, but the present application is not limited to the embodiment. Structural elements of the embodiment described below can be appropriately combined. In addition, there are cases where a part of the structural elements is not used. Figure 1 In the embodiment, the terms "left", "right", "front", "back", "upper", and "lower" and the like are used to describe positional relationships of the parts. These terms indicate relative positions or directions with the center of the electric power tool as a reference.

[0071] The electric power tool has a motor. In the embodiment, a direction parallel to an axis of rotation AX of the motor is appropriately referred to as an axial direction. A radial direction of the axis of rotation AX of the motor is appropriately referred to as a radial direction. A direction around the axis of rotation AX of the motor is appropriately referred to as a circumferential direction or a rotational direction. A direction parallel to a tangent line of an imaginary circle centered on the axis of rotation AX of the motor is appropriately referred to as a tangential direction.

[0072] In the radial direction, a position closer to the axis of rotation AX of the motor or a direction approaching the axis of rotation AX of the motor is appropriately referred to as a radially inner side, and a position farther from the axis of rotation AX of the motor or a direction away from the axis of rotation AX of the motor is appropriately referred to as a radially outer side. A position on one side in the circumferential direction or a direction on one side is appropriately referred to as a circumferential one side, and a position on the other side in the circumferential direction or a direction on the other side is appropriately referred to as a circumferential other side. A position on one side in the tangential direction or a direction on one side is appropriately referred to as a tangential one side, and a position on the other side in the tangential direction or a direction on the other side is appropriately referred to as a tangential other side.

[0073] [First Embodiment]

[0074] [First Embodiment]

[0075] Electric power tool

[0076] Figure 1 Fig. 1 is a perspective view of an electric power tool 1 according to an embodiment. The electric power tool 1 is a hammer drill as one of electric power tools. As shown in Fig. 1, the electric power tool 1 has a housing 2, a rear cover 3, a hammer case 4, a battery mounting portion 5, a motor 601, a fan 7, an anvil 8, a controller 9, a trigger switch 10, a forward-reverse switch lever 11, an operation panel 12, and a lamp 13. Figure 2

[0077] The housing 2 has a motor housing portion 2A, a grip portion 2B, and a controller housing portion 2C. The housing 2 is made of synthetic resin.

[0078] The motor housing portion 2A houses the motor 601. The motor housing portion 2A is cylindrical.

[0079] The grip portion 2B is held by an operator who uses the electric power tool 1. The grip portion 2B protrudes downward from a lower portion of the motor housing portion 2A.

[0080] The controller housing portion 2C houses the controller 9. The controller housing portion 2C is connected to a lower end portion of the grip portion 2B. The outer shape of the controller housing portion 2C is larger in size than the outer shape of the grip portion 2B in the front-rear direction and the left-right direction, respectively.

[0081] The rear cover 3 is connected to a rear portion of the motor housing portion 2A so as to cover an opening of the front portion of the motor housing portion 2A. The rear cover 3 is made of synthetic resin.

[0082] The hammer case 4 is connected to a front portion of the motor housing portion 2A so as to cover an opening of the front portion of the motor housing portion 2A. The hammer case 4 is made of metal.

[0083] The battery pack 14 is mounted to the battery mounting portion 5. The battery mounting portion 5 is provided to a lower portion of the controller housing portion 2C. The battery pack 14 is detachable with respect to the battery mounting portion 5. The battery pack 14 includes a secondary battery. The battery pack 14 includes a lithium-ion battery which is chargeable, in the embodiment. The battery pack 14 is capable of supplying electric power to the electric power tool 1 by being mounted to the battery mounting portion 5. The motor 601 is driven on the basis of the electric power supplied from the battery pack 14. The controller 9 is operated on the basis of the electric power supplied from the battery pack 14.

[0084] The motor 601 is a power source of the electric power tool 1. The motor 601 generates a rotational force which rotates the anvil 8. The motor 601 is a brushless motor. In the embodiment, a rotational axis AX of the motor 601 extends in the front-rear direction. The axial direction and the front-rear direction are parallel.

[0085] ​The fan 7 generates an airflow for cooling the motor 601. The fan 7 is rotated by the rotational force generated by the motor 601.

[0086] The motor housing portion 2A has a suction port 15. The rear cover 3 has a discharge port 16. The discharge port 16 is provided at a position further rearward than the suction port 15. The suction port 15 connects the inside space of the housing 2 and the outside space. The discharge port 16 connects the inside space of the housing 2 and the outside space. The suction port 15 is provided in the left portion and the right portion of the motor housing portion 2A, respectively. The discharge port 16 is provided in the left portion and the right portion of the rear cover 3, respectively. By the rotation of the fan 7, the air of the outside space of the housing 2 flows into the inside space of the housing 2 via the suction port 15, and the motor 601 is cooled. The air of the inside space of the housing 2 flows out to the outside space of the housing 2 via the discharge port 16.

[0087] The hammering portion housing 4 houses the reduction mechanism, the main shaft, and the striking mechanism. The reduction mechanism is disposed at a position further forward than the motor 601. At least a portion of the main shaft is disposed at a position further forward than the reduction mechanism. The reduction mechanism transmits the rotational force generated by the motor 601 to the main shaft. The main shaft rotates about the rotational axis AX by the rotational force of the motor 601 transmitted via the reduction mechanism. The rotational speed of the main shaft is reduced to be lower than the rotational speed of the motor 601 by the reduction mechanism. The striking mechanism strikes the anvil 8 in the rotational direction based on the rotation of the main shaft.

[0088] The anvil 8 rotates about the rotational axis AX based on the rotational force of the motor 601. The anvil 8 has an insertion hole 8A into which a tip tool is inserted. A chucking mechanism 17 for holding the tip tool is provided at least in a portion of the periphery of the anvil 8. The tip tool is held by the chucking mechanism 17 in a state of being inserted into the insertion hole 8A.

[0089] The controller 9 controls the motor 601. The controller 9 controls the drive current supplied from the battery pack 14 to the motor 601. The controller 9 is housed in the controller housing portion 2C. The controller 9 has a substrate on which a plurality of electronic components are mounted. The electronic components mounted on the substrate are, for example, a processor such as a CPU (Central Processing Unit), a nonvolatile memory such as a ROM (Read Only Memory) or a memory, a volatile memory such as a RAM (Random Access Memory), a field effect transistor (FET), and a resistor.

[0090] The trigger switch 10 drives the motor 601. The trigger switch 10 is provided at an upper portion of the grip portion 2B. The trigger switch 10 protrudes forward from an upper portion of a front portion of the grip portion 2B. The motor 601 is driven by moving the trigger switch 10 rearward. The motor 601 is stopped by stopping the operation of the trigger switch 10.

[0091] The forward-reverse switching lever 11 switches the rotation direction of the motor 601. The forward-reverse switching lever 11 is provided at a boundary between a lower end portion of the motor housing portion 2A and an upper end portion of the grip portion 2B. The forward-reverse switching lever 11 is moved in a left direction or a right direction. The rotation direction of the anvil 8 is switched by switching the rotation direction of the motor 601.

[0092] The operation panel 12 is configured at the controller housing portion 2C. The operation panel 12 is plate-shaped. A plurality of operation switches are configured at the operation panel 12. The operation panel 12 outputs an operation signal. The controller 9 switches the control mode of the motor 601 in accordance with the operation signal output from the operation panel 12. The control mode of the motor 601 refers to a control method or a control manner of the motor 601.

[0093] The lamp 13 emits illumination light that illuminates the front of the electric power tool 1. The lamp 13 includes a light emitting diode (LED). The lamp 13 is provided at an upper portion of a front portion of the grip portion 2B.

[0094] < Motor >

[0095] Figure 3 is a perspective view of the motor 601 of the present embodiment as viewed from the rear. Figure 4 is a perspective view of the motor 601 of the present embodiment as viewed from the front. Figure 5 is a perspective view of the stator 20 and the rotor 301 of the present embodiment as viewed from the rear. Figures 2-5 is a perspective view of the stator 20 and the rotor 301 of the present embodiment as viewed from the front.

[0096] The motor 601 of the present embodiment is an inner rotor type brushless motor. As shown in Figure 6 , the motor 601 has a stator 20 and a rotor 301 that rotates with respect to the stator 20. The stator 20 is configured around the rotor 301. The rotor 301 rotates with the rotational axis AX as a center.

[0097] (Stator)

[0098] The stator 20 has a stator core 21, a front insulator 22, a rear insulator 23, a coil 24, a power supply wire 25, a fused terminal 26, a short-circuit member 27, and an insulating member 28. The front insulator 22 and the rear insulator 23 can also be fixed to the stator core 21 by being integrally molded.

[0099] The stator core 21 has a plurality of steel sheets stacked. The steel sheet is a sheet made of a metal having iron as a main component. The stator core 21 is cylindrical. The stator core 21 has a plurality of (six in the present embodiment) tooth portions 21T that support the coils 24. The tooth portions 21T protrude from the inner surface of the stator core 21 toward the radially inner side.

[0100] The front insulator 22 is an electrically insulating member made of synthetic resin. The front insulator 22 is disposed at the front of the stator core 21. The front insulator 22 is cylindrical. The front insulator 22 has a plurality of (six in the present embodiment) protruding portions 22T that support the coils 24. The protruding portions 22T protrude from the inner surface of the front insulator 22 toward the radially inner side.

[0101] The rear insulator 23 is an electrically insulating member made of synthetic resin. The rear insulator 23 is disposed at the rear of the stator core 21. The rear insulator 23 is cylindrical. The rear insulator 23 has a plurality of (six in the present embodiment) protruding portions 23T that support the coils 24. The protruding portions 23T protrude from the inner surface of the rear insulator 23 toward the radially inner side.

[0102] The front end portions of the tooth portions 21T and the rear end portions of the protruding portions 22T are connected. The rear end portions of the tooth portions 21T and the front end portions of the protruding portions 23T are connected.

[0103] The coils 24 are mounted to the stator core 21 with the front insulator 22 and the rear insulator 23 interposed therebetween. The stator 20 has a plurality of (six in the present embodiment) coils 24. The coils 24 are wound around the plurality of tooth portions 21T via the protruding portions 22T and the protruding portions 23T, respectively. The coils 24 are disposed around the tooth portions 21T, the protruding portions 22T, and the protruding portions 23T. The coils 24 and the stator core 21 are insulated by the front insulator 22 and the rear insulator 23.

[0104] The plurality of coils 24 are formed by winding one wire. Adjacent coils 24 in the circumferential direction are connected by a connecting wire 29 that is a portion of the wire. The connecting wire 29 is the wire between one coil 24 and another coil 24. The connecting wire 29 is supported by the front insulator 22.

[0105] The power supply line 25 is connected to the battery pack 14 through the controller 9. The battery pack 14 functions as a power supply portion of the motor 601. The battery pack 14 supplies a drive current to the motor 601 through the controller 9. The controller 9 controls the drive current supplied from the battery pack 14 to the motor 601. The drive current from the battery pack 14 is supplied to the power supply line 25 through the controller 9.

[0106] The fusion terminal 26 is connected to the coil 24 by a connection line 29. The fusion terminal 26 is an electrically conductive member. A plurality of (six in the present embodiment) fusion terminals 26 are arranged around the rotational axis AX. The fusion terminal 26 is provided in the same number as the number of the coils 24.

[0107] The fusion terminal 26 is supported to the front insulator 22. The front insulator 22 of the present embodiment has a support portion 22S that supports the fusion terminal 26. Six support portions 22S are provided at intervals in the circumferential direction. The support portion 22S has a pair of protruding portions 22P that protrude forward from the front surface of the front insulator 22. The fusion terminal 26 is supported to the support portion 22S by being arranged between the pair of protruding portions 22P.

[0108] The connection line 29 is supported to the support portion 22S. The connection line 29 is supported to the outer surface of the protruding portion 22P on the radially outer side. The fusion terminal 26 is connected to the connection line 29 in a state of being arranged between the pair of protruding portions 22P. The connection line 29 is arranged on the inner side of the bent portion of the fusion terminal 26. The fusion terminal 26 and the connection line 29 are welded together. Thereby, the fusion terminal 26 is connected to the connection line 29.

[0109] The short-circuit member 27 connects the fusion terminal 26 and the power supply line 25. The short-circuit member 27 is an electrically conductive member. The short-circuit member 27 is bent in a plane orthogonal to the rotational axis AX. The stator 20 has a plurality of (three in the present embodiment) short-circuit members 27. The short-circuit member 27 short-circuits one power supply line 25 and a pair of fusion terminals 26. The short-circuit member 27 has an opening 27A for arranging the front portion of the fusion terminal 26. By arranging the front portion of the fusion terminal 26 to the opening 27A, the fusion terminal 26 and the short-circuit member 27 are connected together.

[0110] The insulating member 28 supports the power supply line 25 and the short-circuit member 27. The insulating member 28 is made of synthetic resin. The insulating member 28 has a main body portion 28A, a threaded boss portion 28B, and a support portion 28C.

[0111] The main body portion 28A is ring-shaped. In the present embodiment, at least a part of the short-circuit member 27 is arranged inside the main body portion 28A. The short-circuit member 27 is fixed to the main body portion 28A by insert molding. The fusion terminal 26 is supported to the main body portion 28A by the short-circuit member 27. The three short-circuit members 27 are insulated from each other by the main body portion 28A.

[0112] The threaded boss portion 28B protrudes radially outward from the peripheral portion of the main body portion 28A. Four threaded boss portions 28B are provided at the peripheral portion of the main body portion 28A.

[0113] The support portion 28C protrudes downward from the lower portion of the main body portion 28A. The support portion 28C supports the power supply line 25.

[0114] The power supply line 25, the fusion splice terminal 26, the short-circuit member 27, and the insulating member 28 are arranged at a position further forward than the stator core 21. At least a part of the fusion splice terminal 26 is arranged at a position further rearward than the short-circuit member 27 and the insulating member 28.

[0115] Figure 7 is a diagram schematically showing the stator 20 of the present embodiment. Figure 6 is a diagram schematically showing the connection state of the coil 24 of the present embodiment.

[0116] In the present embodiment, the six coils 24 are formed by winding one wire. As shown in Figure 7 and Figure 7 , the wire is wound on the tooth portions 21T from the start winding portion 29S. The six coils 24 are formed by sequentially winding the wire on the circumferentially adjacent tooth portions 21T, respectively. The wire is wound up at the end winding portion 29E.

[0117] As shown in Figures 4-7 , the battery pack 14 supplies a drive current to the power supply line 25 through the controller 9. The drive current supplied to the power supply line 25 is supplied to the fusion splice terminal 26 through the short-circuit member 27. The drive current supplied to the fusion splice terminal 26 is supplied to the coil 24 through the connection line 29.

[0118] The drive current of the present embodiment has a U-phase drive current, a V-phase drive current, and a W-phase drive current.

[0119] As shown in Figure 6 , the power supply line 25 has a U-phase power supply line 25U, a V-phase power supply line 25V, and a W-phase power supply line 25W. The U-phase drive current is supplied to the U-phase power supply line 25U. The V-phase drive current is supplied to the V-phase power supply line 25V. The W-phase drive current is supplied to the W-phase power supply line 25W.

[0120] The short-circuit member 27 has a U-phase short-circuit member 27U, a V-phase short-circuit member 27V, and a W-phase short-circuit member 27W. The U-phase short-circuit member 27U is connected to the U-phase power supply line 25U. The V-phase short-circuit member 27V is connected to the V-phase power supply line 25V. The W-phase short-circuit member 27W is connected to the W-phase power supply line 25W.

[0121] The fusion splice terminal 26 has a pair of U-phase fusion splice terminals 26U, a pair of V-phase fusion splice terminals 26V, and a pair of W-phase fusion splice terminals 26W. The pair of U-phase fusion splice terminals 26U is connected to the U-phase short-circuit member 27U. The pair of V-phase fusion splice terminals 26V is connected to the V-phase short-circuit member 27V. The pair of W-phase fusion splice terminals 26W is connected to the W-phase short-circuit member 27W.

[0122] The six coils 24 are respectively assigned to any one of the U (U-V) phase, the V (V-W) phase, and the W (W-U) phase.

[0123] A pair of coils 24 is assigned to the U-phase, the V-phase, and the W-phase, respectively. The six coils 24 have a pair of U-phase coils 24U assigned to the U-phase, a pair of V-phase coils 24V assigned to the V-phase, and a pair of W-phase coils 24W assigned to the W-phase.

[0124] The pair of U-phase coils 24U (U-phase coils 24U1, 24U2) is arranged facing each other in the radial direction. The pair of V-phase coils 24V (V-phase coils 24V1, 24V2) is arranged facing each other in the radial direction. The pair of W-phase coils 24W (W-phase coils 24W1, 24W2) is arranged facing each other in the radial direction. As shown in FIG. 2, the V-phase coil 24V1 is arranged next to the U-phase coil 24U1 in the circumferential direction. The W-phase coil 24W1 is arranged next to the V-phase coil 24V1. The U-phase coil 24U2 is arranged next to the W-phase coil 24W1. The V-phase coil 24V2 is arranged next to the U-phase coil 24U2. The W-phase coil 24W2 is arranged next to the V-phase coil 24V2. Figure 6

[0125] As shown in FIG. 2, one U-phase fuse terminal 26U is connected to the connecting wire 29 connecting the U-phase coil 24U1 and the V-phase coil 24V1 adjacent to each other in the circumferential direction. The other U-phase fuse terminal 26U is connected to the connecting wire 29 connecting the U-phase coil 24U2 and the V-phase coil 24V2 adjacent to each other in the circumferential direction. Figure 7

[0126] One V-phase fuse terminal 26V is connected to the connecting wire 29 connecting the V-phase coil 24V1 and the W-phase coil 24W1 adjacent to each other in the circumferential direction. The other V-phase fuse terminal 26V is connected to the connecting wire 29 connecting the V-phase coil 24V2 and the W-phase coil 24W2 adjacent to each other in the circumferential direction.

[0127] One W-phase fuse terminal 26W is connected to the connecting wire 29 connecting the W-phase coil 24W1 and the U-phase coil 24U2 adjacent to each other in the circumferential direction. The other W-phase fuse terminal 26W is connected to the connecting wire 29 connecting the W-phase coil 24W2 and the U-phase coil 24U1 adjacent to each other in the circumferential direction.

[0128] The U-phase short-circuit member 27U shorts the U-phase power supply line 25U and the pair of U-phase fuse terminals 26U, respectively. The U-phase power supply line 25U is arranged at one end portion of the U-phase short-circuit member 27U. One U-phase fuse terminal 26U is arranged at the other end portion of the U-phase short-circuit member 27U. The other U-phase fuse terminal 26U is arranged at the intermediate portion of the U-phase short-circuit member 27U.

[0129] ​​The V-phase short-circuit component 27V short-circuites the V-phase power line 25V and a pair of V-phase fusion terminals 26V. The V-phase power line 25V is located at one end of the V-phase short-circuit component 27V. A V-phase fusion terminal 26V is located at the other end of the V-phase short-circuit component 27V. The other V-phase fusion terminal 26V is located in the middle of the V-phase short-circuit component 27V.

[0130] The W-phase short-circuit component 27W short-circuites the W-phase power line 25W and a pair of W-phase fusion terminals 26W respectively. The W-phase power line 25W is located at one end of the W-phase short-circuit component 27W. One W-phase fusion terminal 26W is located at the other end of the W-phase short-circuit component 27W. The other W-phase fusion terminal 26W is located in the middle of the W-phase short-circuit component 27W.

[0131] like Figure 8 As shown, a set of U-phase coils 24U1, V-phase coils 24V1, and W-phase coils 24W1 are connected in a delta configuration. Another set of U-phase coils 24U2, V-phase coils 24V2, and W-phase coils 24W2 are also connected in a delta configuration. One delta connection and the other delta connection are configured in parallel.

[0132] When a U-phase drive current is input into the U-phase power line 25U, the U-phase drive current is supplied to a pair of U-phase fusion terminals 26U through the U-phase short-circuit component 27U. When one U-phase coil 24U1 is energized as the N pole, the other U-phase coil 24U2 is energized as the S pole. The adjacent V-phase coil 24V1 of the U-phase coil 24U1, which is energized as the N pole, is energized as the S pole. The adjacent V-phase coil 24V2 of the U-phase coil 24U2, which is energized as the S pole, is energized as the N pole.

[0133] With a V-phase drive current input to the V-phase power line 25V, the V-phase drive current is supplied to a pair of V-phase fusion terminals 26V through the V-phase short-circuit component 27V. When one V-phase coil 24V1 is energized as the N pole, the other V-phase coil 24V2 is energized as the S pole. The adjacent W-phase coil 24W1 of the V-phase coil 24V1, which is energized as the N pole, is energized as the S pole. The adjacent W-phase coil 24W2 of the V-phase coil 24V2, which is energized as the S pole, is energized as the N pole.

[0134] When a W-phase drive current is input into the W-phase power line 25W, the W-phase drive current is supplied to a pair of W-phase fusion terminals 26W through the W-phase short-circuit component 27W. When one W-phase coil 24W1 is energized as the N pole, the other W-phase coil 24W2 is energized as the S pole. The adjacent U-phase coil 24U2 of the W-phase coil 24W1, which is energized as the N pole, is energized as the S pole. The adjacent U-phase coil 24U1 of the W-phase coil 24W2, which is energized as the S pole, is energized as the N pole.

[0135] (Sensor substrate)

[0136] The electric power tool 1 has a sensor substrate 40. The sensor substrate 40 has a magnetic sensor 43 for detecting rotation of the rotor 301. The sensor substrate 40 is arranged at a position further forward than the front insulator 22. The sensor substrate 40 faces the front insulator 22. The sensor substrate 40 has a plate portion 41, a threaded boss portion 42, the magnetic sensor 43, and a signal line 44.

[0137] The plate portion 41 is annular. In the present embodiment, four threaded boss portions 42 project from a peripheral portion of the plate portion 41 to the radially outer side.

[0138] The magnetic sensor 43 detects rotation of the rotor 301. In the present embodiment, three magnetic sensors 43 are supported to the plate portion 41. The magnetic sensor 43 has a Hall element.

[0139] The detection signal of the magnetic sensor 43 is output to the controller 9 through the signal line 44. The controller 9 supplies drive current to the plurality of coils 24 in accordance with the detection signal of the magnetic sensor 43.

[0140] (Fixing of the insulating member, the sensor substrate, and the front insulator)

[0141] The insulating member 28 that supports the short-circuit member 27, the sensor substrate 40, and the front insulator 22 are fixed by four screws 18. The insulating member 28, the sensor substrate 40, and the front insulator 22 are fixed by the screws 18 in such a manner that the positions of the signal lines 44 and at least a part of the positions of the power supply lines 25 coincide in the circumferential direction.

[0142] An opening 28D for arranging an intermediate portion of the screw 18 is provided in the threaded boss portion 28B of the insulating member 28. An opening 45 for arranging an intermediate portion of the screw 18 is provided in the threaded boss portion 42 of the sensor substrate 40. Four threaded holes 22D are provided in the front surface of the front insulator 22. The top end portion of the screw 18 is combined with the threaded hole 22D in a state where the intermediate portion of the screw 18 is arranged in the opening 28D and the opening 45. Accordingly, the insulating member 28, the sensor substrate 40, and the front insulator 22 are fixed by the screw 18.

[0143] < Rotor >

[0144] Figure 9 is a view of the rotor 301 of the present embodiment as viewed from the left side. Figures 2-5 is a view of the rotor 301 of the present embodiment as viewed from the front.

[0145] As Figure 8 , Figure 9 and Figure 8As shown, rotor 301 has rotor core 31, rotor shaft 32 and permanent magnet 33. Rotor 301 rotates about the rotation axis AX.

[0146] The rotor core 31 has multiple stacked steel plates. The steel plates are made of a metal with iron as the main component. The rotor core 31 surrounds the rotation axis AX.

[0147] The rotor core 31 has a front end 31F and a rear end 31R. The front end 31F is the first end of the rotor core 31 in the axial direction. The rear end 31R is the second end of the rotor core 31 located on the opposite side of the first end in the axial direction.

[0148] The rotor shaft 32 extends axially. The rotor shaft 32 is disposed inside the rotor core 31. The rotor core 31 and the rotor shaft 32 are fixed together. The front portion of the rotor shaft 32 protrudes forward from the front end 31F of the rotor core 31. The rear portion of the rotor shaft 32 protrudes rearward from the rear end 31R of the rotor core 31. The front portion of the rotor shaft 32 is rotatably supported by a front bearing (not shown). The rear portion of the rotor shaft 32 is rotatably supported by a rear bearing (not shown). The front end of the rotor shaft 32 is connected to the aforementioned reduction gear mechanism.

[0149] Permanent magnets 33 are supported on rotor core 31. In this embodiment, the permanent magnets 33 are disposed inside rotor core 31. Motor 601 is an interior permanent magnet (IPM) motor. In this embodiment, four permanent magnets 33 are disposed around the rotation axis AX. Rotor core 31 and permanent magnets 33 are fixed together.

[0150] The permanent magnet 33 is a neodymium iron boron magnet. The remanent magnetic flux density of the permanent magnet 33 is above 1.0T and below 1.5T.

[0151] The sensor substrate 40 is positioned forward of the rotor core 31. For example... Figure 10 As shown, the plate portion 41 of the sensor substrate 40 is disposed around the front portion of the rotor shaft 32. A magnetic sensor 43 is supported on the plate portion 41. The magnetic sensor 43 is positioned facing the front end portion 31F of the rotor core 31. The magnetic sensor 43 detects the rotation of the rotor 301 when positioned facing the front end portion 31F of the rotor core 31. The magnetic sensor 43 detects the position of the rotor 301 in the rotational direction by detecting the magnetic flux of the permanent magnet 33.

[0152] The fan 7 is disposed at a position further rearward than the rotor core 31. The fan 7 is fixed to the rear portion of the rotor shaft 32. At least a portion of the fan 7 faces the rear end portion 31R of the rotor core 31. When the rotor shaft 32 rotates, the fan 7 rotates together with the rotor shaft 32.

[0153] The rotor core 31 of the present embodiment has a first core 311 and a second core 312. The first core 311 includes the front end portion 31F. The second core 312 includes the rear end portion 31R. The second core 312 is adjacent to the first core 311 in the axial direction. The second core 312 is disposed at a position further rearward than the first core 311.

[0154] Figure 10 is a view of the rotor core 31 of the present embodiment as viewed from the left. As shown in Figure 11 The first core 311 includes a plurality of first steel sheets 35 stacked. The plurality of first steel sheets 35 are stacked in the axial direction. The plurality of first steel sheets 35 are connected by riveting to form the first core 311.

[0155] The second core 312 includes a plurality of second steel sheets 36 stacked. The plurality of second steel sheets 36 are stacked in the axial direction. The plurality of second steel sheets 36 are connected by riveting to form the second core 312.

[0156] The rotor core 31 is formed by the first core 311 and the second core 312. The rotor core 31 can also be formed by riveting to connect the plurality of first steel sheets 35 stacked and the plurality of second steel sheets 36 stacked.

[0157] The plurality of first steel sheets 35 have equal thicknesses T1. The plurality of second steel sheets 36 have equal thicknesses T2. The thicknesses T1 of the first steel sheets 35 and the thicknesses T2 of the second steel sheets 36 are equal. The thickness T1 of the first steel sheet 35 refers to the dimension of the first steel sheet 35 in the axial direction. The thickness T2 of the second steel sheet 36 refers to the dimension of the second steel sheet 36 in the axial direction.

[0158] The thickness T1 of the first steel sheet 35 and the thickness T2 of the second steel sheet 36 are, for example, 0.30 mm or more and 0.40 mm or less. In the present embodiment, the thickness T1 of the first steel sheet 35 and the thickness T2 of the second steel sheet 36 are 0.35 mm.

[0159] In the axial direction, the dimension L1 of the first core 311 is smaller than the dimension L2 of the second core 312. The dimension L1 of the first core 311 is, for example, 1.0 mm or more and 2.0 mm or less. The dimension L2 of the second core 312 is, for example, 3.0 mm or more.

[0160] The plurality of first steel plates 35 are identical in shape. The plurality of first steel plates 35 are identical in diameter. The plurality of second steel plates 36 are identical in shape. The plurality of second steel plates 36 are identical in diameter. The shape of the first steel plate 35 is identical to the shape of the second steel plate 36. The diameter of the first steel plate 35 is identical to the diameter of the second steel plate 36.

[0161] The shape of the first steel plate 35 refers to the shape of the outer edge portion of the first steel plate 35 in a plane orthogonal to the rotation axis AX. The shape of the second steel plate 36 refers to the shape of the outer edge portion of the second steel plate 36 in a plane orthogonal to the rotation axis AX. The diameter of the first steel plate 35 refers to the maximum value of the diameter of the first steel plate 35. The diameter of the second steel plate 36 refers to the maximum value of the diameter of the second steel plate 36.

[0162] Figure 12 is a perspective view of the rotor core 31 and the permanent magnet 33 of the present embodiment as viewed from the rear. Figures 10-12 is a perspective view of the rotor core 31 and the permanent magnet 33 of the present embodiment as viewed from the front.

[0163] As shown in Figure 13 , the first core 311 surrounds the rotation axis AX. The second core 312 surrounds the rotation axis AX.

[0164] The first core 311 has a front surface 311F, a rear surface 311R, an outer surface 311S, and an inner surface 311T. The front surface 311F is substantially annular. The rear surface 311R is substantially annular. The outer surface 311S connects the outer edge portion of the front surface 311F and the outer edge portion of the rear surface 311R. The inner surface 311T connects the inner edge portion of the front surface 311F and the inner edge portion of the rear surface 311R. An opening 37 is formed in the central portion of the first core 311. The opening 37 extends in the axial direction. The opening 37 penetrates the front surface 311F and the rear surface 311R of the first core 311. The inner surface 311T of the first core 311 is the inner surface of the opening 37. The front end portion 31F of the rotor core 31 includes the front surface 311F of the first core 311.

[0165] The second core 312 has a front surface 312F, a rear surface 312R, an outer surface 312S, and an inner surface 312T. The front surface 312F is substantially annular. The rear surface 312R is substantially annular. The outer surface 312S connects the outer edge portion of the front surface 312F and the outer edge portion of the rear surface 312R. The inner surface 312T connects the inner edge portion of the front surface 312F and the inner edge portion of the rear surface 312R. An opening 38 is formed in the central portion of the second core 312. The opening 38 extends in the axial direction. The opening 38 penetrates the front surface 312F and the rear surface 312R of the second core 312. The inner surface 312T of the second core 312 is the inner surface of the opening 38. The rear end portion 31R of the rotor core 31 includes the rear surface 312R of the second core 312.

[0166] The rotation axis AX passes through the center of the first iron core 311. The rotation axis AX passes through the center of the second iron core 312. In the radial direction, the distance Rl from the rotation axis AX to the outer surface 311S of the first iron core 311 corresponds to the radius of the first iron core 311. In the radial direction, the distance R2 from the rotation axis AX to the outer surface 312S of the second iron core 312 corresponds to the radius of the second iron core 312. The distance Rl and the distance R2 are equal.

[0167] The distance Rl and the distance R2 are, for example, 15 mm or more and 20 mm or less. In the present embodiment, the distance Rl and the distance R2 are 18 mm.

[0168] The outer shape of the first iron core 311 and the outer shape of the second iron core 312 are equal. The outer shape of the first iron core 311 refers to the shape of the outer edge portion of the first iron core 311 in a plane orthogonal to the rotation axis AX. The outer shape of the second iron core 312 refers to the shape of the outer edge portion of the second iron core 312 in a plane orthogonal to the rotation axis AX.

[0169] The recessed portion 39A is formed in the outer surface 311S of the first iron core 311. The recessed portion 39A extends in the axial direction. The front end portion of the recessed portion 39A is connected to the front surface 311F of the first iron core 311. The rear end portion of the recessed portion 39A is connected to the rear surface 311R of the first iron core 311. A plurality of recessed portions 39A are provided in the outer surface 311S. The plurality of (four in the present embodiment) recessed portions 39A are arranged at equal intervals in the circumferential direction around the rotation axis AX.

[0170] The recessed portion 39B is formed in the outer surface 312S of the second iron core 312. The recessed portion 39B extends in the axial direction. The front end portion of the recessed portion 39B is connected to the front surface 312F of the second iron core 312. The rear end portion of the recessed portion 39B is connected to the rear surface 312R of the second iron core 312. A plurality of recessed portions 39B are provided in the outer surface 312S. The plurality of (four in the present embodiment) recessed portions 39B are arranged at equal intervals in the circumferential direction around the rotation axis AX.

[0171] The recessed portion 39A and the recessed portion 39B each suppress noise generated due to rotation of the rotor iron core 31. In addition, one or both of the recessed portion 39A and the recessed portion 39B can be omitted.

[0172] The first iron core 311 and the second iron core 312 are connected in such a manner that the rear surface 311R of the first iron core 311 and the front surface 312F of the second iron core 312 are in contact with each other. The first iron core 311 and the second iron core 312 are connected in such a manner that each of the plurality of recessed portions 39A and each of the plurality of recessed portions 39B are connected to each other.

[0173] The first core 311 has a plurality of (four in this embodiment) first holes 51. The plurality of (four in this embodiment) first holes 51 are spaced apart circumferentially. The second core 312 has a plurality of second holes 52. The plurality of second holes 52 are spaced apart circumferentially. The number of first holes 51 and the number of second holes 52 are equal.

[0174] Multiple first holes 51 are provided at intervals around the axis of rotation AX. The first holes 51 penetrate the front surface 311F and the rear surface 311R of the first iron core 311.

[0175] Multiple second holes 52 are provided at intervals around the axis of rotation AX. The second holes 52 penetrate the front surface 312F and the rear surface 312R of the second iron core 312.

[0176] Permanent magnets 33 are respectively disposed in the first hole 51 and the second hole 52. A plurality of (four in this embodiment) permanent magnets 33 are arranged around the rotation axis AX. The permanent magnets 33 are plate-shaped. The permanent magnets 33 are cuboid in shape. The permanent magnets 33 are axially elongated.

[0177] The permanent magnet 33 has an inner surface 33A, an outer surface 33B, a front surface 33C, a rear surface 33D, a first side surface 33E, and a second side surface 33F. The inner surface 33A faces radially inward. The outer surface 33B faces radially outward. The front surface 33C faces forward. The rear surface 33D faces rearward. The first side surface 33E faces one circumferential side. The second side surface 33F faces the other circumferential side.

[0178] The first iron core 311 and the second iron core 312 are connected in such a way that at least a portion of a first hole 51 and a second hole 52 overlap. A magnet hole 50 is formed by the first hole 51 and the second hole 52 overlapping at least a portion of the first hole 51. In this embodiment, four magnet holes 50 are provided on the rotor iron core 31. A permanent magnet 33 is disposed in each of the plurality of magnet holes 50.

[0179] Figure 13 This is a view of the rotor core 31 of this embodiment from the front. (See diagram.) Figure 14 The plurality of first holes 51 are arranged at equal intervals along the circumference. In a plane orthogonal to the rotation axis AX, the plurality of first holes 51 have the same shape. In a plane orthogonal to the rotation axis AX, the plurality of first holes 51 have the same size.

[0180] In the first iron core 311, a first portion 61 of the first iron core 311 is disposed between adjacent first holes 51 in the circumferential direction. The dimension of the first portion 61 in the circumferential direction is W1.

[0181] The plurality of first portions 61 are arranged equidistantly in the circumferential direction. The sizes W1 of the plurality of first portions 61 are equal.

[0182] In the radial direction, the distance from the rotation axis AX to the first portion 61 is C1. The distance C1 from the rotation axis AX to each of the plurality of first portions 61 is equal.

[0183] Figure 14 is a view of the rotor core 31 of the present embodiment as viewed from the rear. As shown in Figure 13 The plurality of second holes 52 are arranged equidistantly in the circumferential direction. In a plane orthogonal to the rotation axis AX, the shapes of the plurality of second holes 52 are identical. In the plane orthogonal to the rotation axis AX, the sizes of the plurality of second holes 52 are equal.

[0184] In the second core 312, between the second holes 52 adjacent in the circumferential direction, a second portion 62 of the second core 312 is arranged. In the circumferential direction, the size of the second portion 62 is W2.

[0185] The plurality of second portions 62 are arranged equidistantly in the circumferential direction. The sizes W2 of the plurality of second portions 62 are equal.

[0186] In the radial direction, the distance from the rotation axis AX to the second portion 62 is C2. The distance C2 from the rotation axis AX to each of the plurality of second portions 62 is equal.

[0187] As shown in Figure 14 and Figure 13 The number of first portions 61 and the number of second portions 62 are equal. In the present embodiment, four first portions 61 and four second portions 62 are arranged in the circumferential direction.

[0188] In the circumferential direction, the size W1 of the first portion 61 is smaller than the size W2 of the second portion 62.

[0189] The size W1 of the first portion 61 is equal to or greater than 0.2 mm and equal to or less than 1.0 mm. The size W2 of the second portion 62 is equal to or greater than 2.0 mm and equal to or less than 10.0 mm.

[0190] The distance C1 from the rotation axis AX to the first portion 61 and the distance C2 from the rotation axis AX to the second portion 62 are equal.

[0191] As shown in Figure 14 A first gap 71 is formed between the surface of the permanent magnet 33 arranged in the first hole 51 and at least a portion of the inner surface of the first hole 51. The first gap 71 of the present embodiment faces the first side surface 33E and the second side surface 33F, respectively. The first resin 73 is arranged in the first gap 71.

[0192] As shown in Figure 15As shown, the second gap 72 is formed between the surface of the permanent magnet 33 disposed in the second hole 52 and at least a portion of the inner surface of the second hole 52. The second gap 72 of the present embodiment faces the first side surface 33E and the second side surface 33F, respectively. The second resin 74 is disposed in the second gap 72.

[0193] The permanent magnet 33 has a first permanent magnet 331 and a second permanent magnet 332. The S pole of the first permanent magnet 331 faces the radially outer side. The N pole of the second permanent magnet 332 faces the radially outer side. In the circumferential direction, the first permanent magnet 331 and the second permanent magnet 332 are alternately disposed. Four permanent magnets 33 are disposed around the rotation axis AX. The permanent magnet 33 has two first permanent magnets 331 and two second permanent magnets 332.

[0194] Figure 10 is a cross-sectional view of the first core 311 of the present embodiment, corresponding to Figure 16 the A-A cross-sectional view. Figure 15 is a cross-sectional view of the first core 311 of the present embodiment, partially enlarged.

[0195] As shown in Figure 16 and Figure 17 , the inner surface of the first hole 51 has a first support surface 51A, a second support surface 51B, a third support surface 51E, a fourth support surface 51F, a first extension surface 51G, a first facing surface 51H, a first connecting surface 51I, a second extension surface 51J, a second facing surface 51K, and a second connecting surface 51L.

[0196] The first support surface 51A faces the radially outer side. The first support surface 51A is parallel to the tangent line of the imaginary circle centered on the rotation axis AX. The first support surface 51A faces the inner surface 33A of the permanent magnet 33.

[0197] The second support surface 51B faces the radially inner side. The second support surface 51B is parallel to the tangent line of the imaginary circle centered on the rotation axis AX. The second support surface 51B faces the outer surface 33B of the permanent magnet 33.

[0198] The third support surface 51E faces the other side in the tangent direction. The third support surface 51E is connected to the end portion on the one side in the tangent direction of the second support surface 51B. The third support surface 51E faces a portion on the radially outer side of the first side surface 33E of the permanent magnet 33.

[0199] The fourth support surface 51F faces the one side in the tangent direction. The fourth support surface 51F is connected to the end portion on the other side in the tangent direction of the second support surface 51B. The fourth support surface 51F faces a portion on the radially outer side of the second side surface 33F of the permanent magnet 33.

[0200] The permanent magnet 33 is supported on the first support surface 51A, the second support surface 51B, the third support surface 51E, and the fourth support surface 51F.

[0201] The first extension surface 51G faces the radially outer side. The first extension surface 51G extends from the end of the first support surface 51A to the tangential direction one side.

[0202] The first facing surface 51H faces the radially inner side. The first facing surface 51H faces at least a portion of the first extension surface 51G. The first facing surface 51H is connected to the end on the radially inner side of the third support surface 51E.

[0203] The first connecting surface 51I connects the end on the tangential direction one side of the first extension surface 51G and the end on the tangential direction one side of the first facing surface 51H.

[0204] The second extension surface 51J faces the radially outer side. The second extension surface 51J extends from the end of the first support surface 51A to the tangential direction other side.

[0205] The second facing surface 51K faces the radially inner side. The second facing surface 51K faces at least a portion of the second extension surface 51J. The second facing surface 51K is connected to the end on the radially inner side of the fourth support surface 51F.

[0206] The second connecting surface 51L connects the end on the tangential direction other side of the second extension surface 51J and the end on the tangential direction other side of the second facing surface 51K.

[0207] In the first hole 51, one first gap 71 is formed between the first side surface 33E of the permanent magnet 33, the first extension surface 51G, the first facing surface 51H, and the first connecting surface 51I. The other first gap 71 is formed between the second side surface 33F of the permanent magnet 33, the second extension surface 51J, the second facing surface 51K, and the second connecting surface 51L.

[0208] By disposing the first resin 73 in the first gap 71, the permanent magnet 33 can be inhibited from moving inside the magnet hole 50. In addition, the first resin 73 can also be disposed between the outer surface 33B of the permanent magnet 33 and the second support surface 51B of the first hole 51. Accordingly, the permanent magnet 33 is firmly fixed to the rotor core 31.

[0209] Figure 10 is a cross-sectional view of the second core 312 of the present embodiment, corresponding to the B-B cross-sectional view of Figure 18 . Figure 17 is a cross-sectional view of the second core 312 of the present embodiment, partially enlarged.

[0210] As Figure 18 and Figure 15As shown, the inner surface of the second hole 52 has a fifth support surface 52A, a sixth support surface 52B, a seventh support surface 52E, an eighth support surface 52F, a third extension surface 52H, a third facing surface 52G, a third connecting surface 521, a fourth extension surface 52K, a fourth facing surface 52J, and a fourth connecting surface 52L.

[0211] The fifth support surface 52A faces the radially outer side. The fifth support surface 52A is parallel to a tangent line of an imaginary circle centered on the rotational axis AX. The fifth support surface 52A faces the inner surface 33A of the permanent magnet 33.

[0212] The sixth support surface 52B faces the radially inner side. The sixth support surface 52B is parallel to a tangent line of an imaginary circle centered on the rotational axis AX. The sixth support surface 52B faces the outer surface 33B of the permanent magnet 33.

[0213] The seventh support surface 52E faces the tangent line direction other side. The seventh support surface 52E is connected to the end portion of the fifth support surface 52A on the tangent line direction one side. The seventh support surface 52E faces a portion of the radially inner side of the first side surface 33E of the permanent magnet 33.

[0214] The eighth support surface 52F faces the tangent line direction one side. The eighth support surface 52F is connected to the end portion of the fifth support surface 52A on the tangent line direction other side. The eighth support surface 52F faces a portion of the radially inner side of the second side surface 33F of the permanent magnet 33.

[0215] The permanent magnet 33 is supported by the fifth support surface 52A, the sixth support surface 52B, the seventh support surface 52E, and the eighth support surface 52F.

[0216] The third extension surface 52H faces the radially inner side. The third extension surface 52H extends from the end portion of the sixth support surface 52B to the tangent line direction one side.

[0217] The third facing surface 52G faces the radially outer side. The third facing surface 52G faces at least a portion of the third extension surface 52H. The third facing surface 52G is connected to the end portion of the seventh support surface 52E on the radially outer side.

[0218] The third connecting surface 52I connects the end portion of the third extension surface 52H on the tangent line direction one side and the end portion of the third facing surface 52G on the tangent line direction one side.

[0219] The fourth extension surface 52K faces the radially inner side. The fourth extension surface 52K extends from the end portion of the sixth support surface 52B to the tangent line direction other side.

[0220] The fourth facing surface 52J faces the radially outer side. The fourth facing surface 52J faces at least a portion of the fourth extension surface 52K. The fourth facing surface 52J is connected to the end portion of the eighth support surface 52F on the radially outer side.

[0221] The fourth connecting surface 52L connects the end portion on the other side in the tangential direction of the fourth extension surface 52K and the end portion on the other side in the tangential direction of the fourth facing surface 52J.

[0222] In one of the second holes 52, one of the second gaps 72 is formed between the first side surface 33E of the permanent magnet 33, the third extension surface 52H, the third facing surface 52G, and the third connecting surface 52I. The other of the second gaps 72 is formed between the second side surface 33F of the permanent magnet 33, the fourth extension surface 52K, the fourth facing surface 52J, and the fourth connecting surface 52L.

[0223] By providing the second resin 74 in the second gap 72, the movement of the permanent magnet 33 inside the magnet hole 50 can be suppressed. In addition, the second resin 74 can also be provided between the outer surface 33B of the permanent magnet 33 and the sixth supporting surface 52B of the second hole 52. Accordingly, the permanent magnet 33 is firmly fixed to the rotor core 31.

[0224] In the tangential direction, the size El of the first hole 51 is larger than the size E2 of the second hole 52.

[0225] In the radial direction, the size Hl of the first hole 51 and the size H2 of the second hole 52 are equal. The size Hl is the distance between the first supporting surface 51A and the second supporting surface 51B in the radial direction. The size H2 is the distance between the fifth supporting surface 52A and the sixth supporting surface 52B in the radial direction.

[0226] The first core 311 and the second core 312 are connected in such a manner that the center of the first hole 51 and the center of the second hole 52 coincide in the tangential direction or the circumferential direction. In addition, the first core 311 and the second core 312 are connected in such a manner that the center of the first hole 51 and the center of the second hole 52 coincide in the radial direction.

[0227] In the state where the first core 311 and the second core 312 are connected together, the first supporting surface 51A and the fifth supporting surface 52A are connected, and the second supporting surface 51B and the sixth supporting surface 52B are connected. The first supporting surface 51A and the fifth supporting surface 52A are coplanar. The second supporting surface 51B and the sixth supporting surface 52B are coplanar. The third supporting surface 51E is provided at a position that is radially outward of the seventh supporting surface 52E. The fourth supporting surface 51F is provided at a position that is radially outward of the eighth supporting surface 52F. In the state where the first core 311 and the second core 312 are connected, at least a part of the first gap 71 and the second gap 72 overlap. At least a part of the second gap 72 is provided at a position that is radially outward of the first gap 71.

[0228] <Operation>

[0229] Next, the operation of the motor 601 will be described. When the trigger switch 10 is operated, a drive current is supplied from the battery pack 14 to the coil 24 of the stator 20 by the controller 9. Accordingly, a rotating magnetic field is generated in the stator 20, as shown by the arrow MF in Figure 17 and Figure 15 , the magnetic flux flows in the rotor core 31. When the rotating magnetic field is generated in the stator 20, the rotor 301 rotates about the rotational axis AX.

[0230] In the motor 601, a magnetic torque and a reluctance torque are generated. The magnetic torque refers to a torque generated due to the attractive and repulsive forces of the rotating magnetic field of the stator 20 and the permanent magnet 33 of the rotor 301. The reluctance torque refers to a torque generated due to the attractive force of the rotating magnetic field of the stator 20 and the rotor core 31 of the rotor 301. The torque generated by the motor 601 is a resultant torque of the magnetic torque and the reluctance torque.

[0231] The magnetic torque becomes larger in the case where the amount of the permanent magnet 33 is large. The magnetic torque becomes smaller in the case where the amount of the permanent magnet 33 is small. The reluctance torque becomes larger in the case where the passage of the magnetic flux of the rotor core 31 is large. The reluctance torque becomes smaller in the case where the passage of the magnetic flux of the rotor core 31 is small.

[0232] As shown in Figure 17 and Figure 19 , the first portion 61 and the second portion 62 are passages of the magnetic flux of the rotor core 31, respectively. In the present embodiment, the size W2 of the second portion 62 is larger than the size Wl of the first portion 61. That is, the passage of the magnetic flux in the second core 312 is larger than the passage of the magnetic flux in the first core 311. The reluctance torque of the second core 312 with respect to the stator 20 is larger than the reluctance torque of the first core 311 with respect to the stator 20.

[0233] The passage of the magnetic flux of the second core 312, that is, the size W2 of the second portion 62 is large, and thus, even if the amount of the permanent magnet 33 is reduced, the motor 601 can generate a prescribed resultant torque. In the case where the amount of the permanent magnet 33 is small, the production cost of the motor 601 is suppressed.

[0234] The magnetic sensor 43 detects the switching of the magnetic poles of the first permanent magnet 331 and the magnetic poles of the second permanent magnet 332 that occurs along with the rotation of the rotor 301, thereby detecting the rotation of the rotor 301. That is, the magnetic sensor 43 detects the direction of the magnetic field that changes based on the rotation of the rotor 301. As described above, the S pole of the first permanent magnet 331 faces the radially outer side. The N pole of the second permanent magnet 332 faces the radially outer side.

[0235] When the rotor 30 rotates, the magnetic pole of the permanent magnet 33 that is closest to the magnetic sensor 43 switches between the S pole of the first permanent magnet 331 and the N pole of the second permanent magnet 332. The direction of the magnetic field when switching from the S pole of the first permanent magnet 331 to the N pole of the second permanent magnet 332 is different from the direction of the magnetic field when switching from the N pole of the second permanent magnet 332 to the S pole of the first permanent magnet 331. Therefore, the magnetic sensor 43 detects the direction of the magnetic field that changes based on the rotation of the rotor 301, thereby detecting the switching of the magnetic pole (S pole or N pole) of the permanent magnet 33 that occurs in conjunction with the rotation of the rotor 301. Accordingly, the magnetic sensor 43 detects the rotation of the rotor 301.

[0236] In a case where the passage of the magnetic flux of the rotor core 31 is large, the magnetic sensor 43 can have difficulty in accurately detecting the switching of the magnetic pole of the permanent magnet 33 that occurs in conjunction with the rotation of the rotor 301 due to the magnetic flux leaked from the rotor core 31. As a result, the detection accuracy of the rotation of the rotor 301 can decrease.

[0237] In the present embodiment, the size W1 of the first portion 61 is smaller than the size W2 of the second portion 62. That is, the passage of the magnetic flux in the first core 311 is smaller than the passage of the magnetic flux in the second core 312. The reluctance torque of the first core 311 with respect to the stator 20 is smaller than the reluctance torque of the second core 312 with respect to the stator 20.

[0238] The passage of the magnetic flux of the first core 311, that is, the size W1 of the first portion 61 is small, and thus the magnetic flux leaked from the rotor core 31 is suppressed. Accordingly, the magnetic sensor 43 is suppressed from being affected by the magnetic flux leaked from the rotor core 31. Therefore, the magnetic sensor 43 can accurately detect the switching of the magnetic pole of the permanent magnet 33 that occurs in conjunction with the rotation of the rotor 301. Thus, the decrease in the detection accuracy of the rotation of the rotor 301 is suppressed.

[0239] Figure 19 is a graph that shows the relationship between the size of the passage of the magnetic flux of the rotor core 31, the magnetic flux detected by the magnetic sensor 43, and the rotation angle of the rotor 301. Figure 19 indicates the magnetic flux detected by one magnetic sensor 43 when the rotor 301 rotates one revolution.

[0240] In Figure 19 , the line La indicates the magnetic flux detected by the magnetic sensor 43 in a case where the passage of the magnetic flux of the rotor core 31 is small. The line Lb indicates the magnetic flux detected by the magnetic sensor 43 in a case where the passage of the magnetic flux of the rotor core 31 is large.

[0241] The magnetic sensor 43 detects the direction of the magnetic field that changes based on the rotation of the rotor 301. In a case where the passage of the magnetic flux of the rotor core 31 is large, as shown by the line Lb, when the magnetic pole of the permanent magnet 33 detected by the magnetic sensor 43 switches from the N pole to the S pole, a magnetic field in a direction opposite to the direction of the magnetic field generated by the permanent magnet 33 can be generated due to the magnetic flux leaked from the rotor core 31, as shown by the arrow Vn. Likewise, when the magnetic pole of the permanent magnet 33 detected by the magnetic sensor 43 switches from the S pole to the N pole, a magnetic field in a direction opposite to the direction of the magnetic field generated by the permanent magnet 33 can be generated due to the magnetic flux leaked from the rotor core 31, as shown by the arrow Vs. That is, in a case where the passage of the magnetic flux of the rotor core 31 is large, the number of times of change in the direction of the magnetic field that occurs at the detection position of the magnetic sensor 43 during one rotation of the rotor 301 is larger than the number of the permanent magnets 33. As a result, the magnetic sensor 43 can not accurately detect the switching of the magnetic pole of the permanent magnet 33. The detection position of the magnetic sensor 43 includes a position facing the magnetic sensor 43.

[0242] In the present embodiment, the size W1 of the first portion 61 of the first core 311 is defined so that the number of times of change in the direction of the magnetic field that occurs at the detection position of the magnetic sensor 43 during one rotation of the rotor 301 is equal to the number of the permanent magnets 33. The number of the permanent magnets 33 of the present embodiment is four. As shown by the line La, the size W1 of the first portion 61 is defined so that the number of times of change in the direction of the magnetic field that occurs during one rotation of the rotor 301 is four, that is, a magnetic field in a direction opposite to the direction of the magnetic field generated by the permanent magnet 33 is not generated. Accordingly, the decrease in the detection accuracy of the rotation of the rotor 301 is suppressed.

[0243] As described above, according to the present embodiment, the rotor core 31 has the first core 311 including the front end portion 31F and the second core 312 adjacent to the first core 311 in the axial direction. The magnetic sensor 43 is disposed at a position facing the first core 311. The first core 311 has the first portion 61 disposed between the first holes 51 adjacent in the circumferential direction. The second core 312 has the second portion 62 disposed between the second holes 52 adjacent in the circumferential direction. The first portion 61 is a passage of the magnetic flux of the first core 311. The second portion 62 is a passage of the magnetic flux of the second core 312. In the circumferential direction, the size W1 of the first portion 61 is smaller than the size W2 of the second portion 62. Since the passage of the magnetic flux of the first core 311 facing the magnetic sensor 43 is small, the leakage of the magnetic flux from the rotor core 31 to the magnetic sensor 43 is suppressed. Therefore, the magnetic sensor 43 can accurately detect the switching of the magnetic pole of the permanent magnet 33 that occurs with the rotation of the rotor 301. Accordingly, the decrease in the detection accuracy of the rotation of the rotor 301 is suppressed.

[0244] The size W2 of the second portion 62 is larger than the size Wl of the first portion 61. The passage of the magnetic flux of the second core 312 is large, and thus a large reluctance torque is generated in the second core 312. Therefore, the shortage of the reluctance torque is suppressed. In addition, even if the amount of the permanent magnet 33 is reduced, the motor 601 is able to generate a prescribed resultant torque. In the case where the amount of the permanent magnet 33 is small, the production cost of the motor 601 is suppressed.

[0245] The plurality of first portions 61 are provided in the circumferential direction. The sizes Wl of the plurality of first portions 61 are equal. Therefore, the magnetic sensor 43 is able to accurately detect the switching of the magnetic pole of the permanent magnet 33 that occurs in conjunction with the rotation of the rotor 301.

[0246] The plurality of second portions 62 are provided in the circumferential direction. The sizes W2 of the plurality of second portions 62 are equal. Therefore, the reluctance torque that is generated in the rotation of the rotor 301 is uniformized.

[0247] The magnetic sensor 43 detects the direction of the magnetic field that changes based on the rotation of the rotor 301. As described with reference to Figure 15 The size Wl of the first portion 61 is prescribed in such a manner that the number of times of change in the direction of the magnetic field that occurs in the course of one rotation of the rotor 301 is equal to the number of the permanent magnets 33. Therefore, the magnetic sensor 43 is able to accurately detect the switching of the magnetic pole of the permanent magnet 33 that occurs in conjunction with the rotation of the rotor 301.

[0248] The size Wl of the first portion 61 is 0.2 mm or more and 1.0 mm or less. Thereby, the number of times of change in the direction of the magnetic field that occurs in the course of one rotation of the rotor 301 is equal to the number of the permanent magnets 33. The permanent magnet 33 of the present embodiment is a neodymium-iron-boron magnet. In the case where the residual magnetic flux density of the permanent magnet 33 is 1.0 T or more and 1.5 T or less, by making the size Wl 0.2 mm or more and 1.0 mm or less, the likelihood that the number of times of change in the direction of the magnetic field that occurs in the course of one rotation of the rotor 301 is equal to the number of the permanent magnets 33 is high.

[0249] The size W2 of the second portion 62 is 2.0 mm or more and 10.0 mm or less. Thereby, a sufficient reluctance torque is generated. The permanent magnet 33 of the present embodiment is a neodymium-iron-boron magnet. In the case where the residual magnetic flux density of the permanent magnet 33 is 1.0 T or more and 1.5 T or less, by making the size W2 2.0 mm or more and 10.0 mm or less, the likelihood that a sufficient reluctance torque is generated is high. In addition, even if the permanent magnet 33 is formed of a material other than a neodymium-iron-boron magnet, if it is a permanent magnet 33 having a residual magnetic flux density equal to or more than that of a neodymium-iron-boron magnet, by making the size W2 2.0 mm or more and 10.0 mm or less, the likelihood that a sufficient reluctance torque is generated is also high.

[0250] The number of the first holes 51 is equal to the number of the second holes 52. One magnet hole 50 is formed by the first hole 51 and the second hole 52 overlapping at least a portion of the first hole 51. One permanent magnet 33 is disposed in each of the plurality of magnet holes 50. Accordingly, the permanent magnet 33 can be disposed in the magnet hole 50 smoothly.

[0251] The first core 311 and the second core 312 are connected in a manner that the center of the first hole 51 coincides with the center of the second hole 52. Accordingly, the weight balance of the rotor 301 is good, and thus the rotor 301 can rotate smoothly. In addition, the permanent magnet 33 can be disposed in the magnet hole 50 smoothly.

[0252] In the radial direction, the size Hl of the first hole 51 is equal to the size H2 of the second hole 52. Accordingly, the cuboid-shaped permanent magnet 33 that is long in the axial direction is disposed stably in the first hole 51 and the second hole 52.

[0253] A first gap 71 is formed between the surface of the permanent magnet 33 and at least a portion of the inner surface of the first hole 51. A second gap 72 is formed between the surface of the permanent magnet 33 and at least a portion of the inner surface of the second hole 52. Accordingly, the magnetic flux of the permanent magnet 33 and the magnetic flux passing through the rotor core 31 are suppressed from leaking. Figure 17 and Figure 20 the magnetic flux passing through the rotor core 31 as indicated by the arrow MF.

[0254] A first resin 73 is disposed in the first gap 71. A second resin 74 is disposed in the second gap 72. Accordingly, the permanent magnet 33 is suppressed from moving inside the magnet hole 50.

[0255] The plurality of first holes 51 have the same shape and size. The plurality of second holes 52 have the same shape and size. Accordingly, the weight balance of the rotor 301 is good, and thus the rotor 301 can rotate smoothly.

[0256] In the axial direction, the size Ll of the first core 311 is smaller than the size L2 of the second core 312. When the size L2 of the second core 312 is smaller than the size Ll of the first core 311, there is a possibility that the reluctance torque occurring in the second core 312 is insufficient. Even if the size Ll of the first core 311 is short, the magnetic field in the direction opposite to the direction of the magnetic field generated by the permanent magnet 33 can be suppressed from being generated. By making the size Ll of the first core 311 smaller than the size L2 of the second core 312, the detection accuracy of the rotation of the rotor 301 can be suppressed from decreasing while suppressing the insufficiency of the reluctance torque.

[0257] The size LI of the first core 311 is 1.0 mm or more and 2.0 mm or less. When the size LI is less than 1.0 mm, the effect of suppressing the generation of a magnetic field in a direction opposite to the direction of the magnetic field generated by the permanent magnet 33 cannot be sufficiently obtained. In addition, even if the size LI is made longer than 2.0 mm, the improvement of the effect of suppressing the generation of a magnetic field in a direction opposite to the direction of the magnetic field generated by the permanent magnet 33 is attenuated. By making the size LI of the first core 311 1.0 mm or more and 2.0 mm or less, it is possible to suppress the decrease in the detection accuracy of the rotation of the rotor 301 while suppressing the insufficiency of the magnetic drag torque.

[0258] In the radial direction, the distance CI from the rotation axis AX to each of the plurality of first portions 61 is equal. In the radial direction, the distance C2 from the rotation axis AX to each of the plurality of second portions 62 is equal. By this, the weight balance of the rotor 301 is good, and thus the rotor 301 can rotate smoothly. In addition, since the distance CI from the rotation axis AX to each of the plurality of first portions 61 is equal, the detection signal of the magnetic sensor 43 is suppressed from being biased.

[0259] In the radial direction, the distance CI from the rotation axis AX to the first portion 61 and the distance C2 from the rotation axis AX to the second portion 62 are equal. By this, the weight balance of the rotor 301 is good, and thus the rotor 301 can rotate smoothly.

[0260] In the radial direction, the distance Rl from the rotation axis AX to the outer surface 311S of the first core 311 and the distance R2 from the rotation axis AX to the outer surface 312S of the second core 312 are equal. By this, the rotor core 31 can rotate smoothly in a state of being disposed inside the stator 20.

[0261] The outer shape of the first core 311 and the outer shape of the second core 312 are equal. By this, the rotor core 31 can rotate smoothly in a state of being disposed inside the stator 20.

[0262] The first core 311 has a plurality of first steel sheets 35 stacked. The second core 312 has a plurality of second steel sheets 36 stacked. The thickness Tl and the outer shape of the first steel sheet 35 and the thickness T2 and the outer shape of the second steel sheet 36 are the same. By this, the production cost of the rotor core 31 is suppressed.

[0263] <Another Embodiment>

[0264] Figure 20 is a perspective view of the rotor 301B of another embodiment of the present embodiment, as viewed from the rear. As Figure 20As shown, the rotor core 31 has a first core 311, a second core 312, and a third core 313. The first core 311 includes the front end portion 31F of the rotor core 31. The third core 313 includes the rear end portion 31R of the rotor core 31. In the axial direction, the second core 312 is disposed between the first core 311 and the third core 313.

[0265] The shape of the third core 313 is the same as the shape of the first core 311. The size of the third core 313 is equal to the size of the first core 311. That is, the first core 311 and the third core 313 are identical.

[0266] According to Figure 21 In the example shown, for example, when the rotor core 31 and the rotor shaft 32 are fixed, the same rotor 301 can be produced even if the direction in the axial direction of the rotor core 31 is reversed. Therefore, the generation efficiency of the rotor 301 is suppressed from decreasing.

[0267] [Second Embodiment]

[0268] The second embodiment will be described. In the following description, the same reference numerals are assigned to the same or equivalent structural elements as those of the above-described embodiments, and the description thereof is simplified or omitted.

[0269] <Outdoor Power Equipment>

[0270] Figure 22 is a perspective view of an outdoor power equipment 101 of the present embodiment. In the present embodiment, the outdoor power equipment 101 is a chain saw as one kind of outdoor power equipment.

[0271] The outdoor power equipment 101 has a housing 102, a guard 103, a first grip portion 104, a battery mounting portion 105, a motor 602, a trigger switch 106, a trigger lock lever 107, a guide lever 108, and a saw chain 109.

[0272] The housing 102 is formed of synthetic resin. The housing 102 has a motor housing portion 110, a battery holding portion 111, and a second grip portion 112.

[0273] The motor housing portion 110 houses the motor 602. The battery holding portion 111 is connected to the motor housing portion 110. The battery holding portion 111 has the battery mounting portion 105 for mounting the battery pack 14. The battery holding portion 111 houses the controller 9. The second grip portion 112 is connected to the battery holding portion 111. The trigger switch 106 and the trigger lock lever 107 are disposed in the second grip portion 112. The operation of the trigger switch 106 is allowed by operating the trigger lock lever 107.

[0274] The guide rod 108 is supported to the housing 102. The guide rod 108 is a plate-like member. The saw chain 109 has a plurality of cutters connected together. The saw chain 109 is arranged at a peripheral portion of the guide rod 108. When the trigger switch 106 is operated, the motor 602 is driven. The motor 602 and the saw chain 109 are connected through a power transmission mechanism (not shown) including a sprocket. By the driving of the motor 602, the saw chain 109 moves along the peripheral portion of the guide rod 108.

[0275] The sprocket is directly fixed to the rotor shaft 32 of the motor 602. That is, the motor 602 of the embodiment drives the saw chain 109 in a so-called direct drive manner. No speed reduction mechanism is arranged between the motor 602 and the sprocket. In addition, a speed reduction mechanism can also be arranged. By arranging the speed reduction mechanism, the saw chain 109 can be driven with high torque.

[0276] The first grip portion 104 is formed of synthetic resin. The first grip portion 104 is held by an operator who uses the power working machine 101. The first grip portion 104 is a tubular member. The first grip portion 104 is connected to the battery holding portion 111. One end portion and the other end portion of the first grip portion 104 are connected to the surface of the battery holding portion 111, respectively.

[0277] <rotor>

[0278] Figure 23 is a perspective view of the rotor 302 of the embodiment, as viewed from the rear. Figure 24 is a perspective view of the rotor 302 of the embodiment, as viewed from the front. Figure 25 is a perspective view of the rotor core 31 of the embodiment, as viewed from the front. Figure 26 is a view of the rotor core 31 of the embodiment, as viewed from the front. Figure 27 is a view of the rotor core 31 of the embodiment, as viewed from the rear. Figure 24 is a sectional view of the first core 311 of the embodiment, corresponding to a C-C sectional view of Figure 28 . Figure 29 is a sectional view of the first core 311 of the embodiment, partially enlarged. Figure 24 is a sectional view of the second core 312 of the embodiment, corresponding to a D-D sectional view of Figure 30 . Figures 22-30 is a sectional view of the first core 311 of the embodiment, partially enlarged.

[0279] As shown in Figure 28 , the rotor 302 has a rotor core 31, a rotor shaft 32, and a permanent magnet 33.

[0280] The rotor core 31 has a front end portion 31F and a rear end portion 31R. As with the above-described embodiment, the magnetic sensor 43 is disposed at a position facing the front end portion 31F of the rotor core 31.

[0281] The permanent magnets 33 are supported to the rotor core 31. In the present embodiment, eight permanent magnets 33 are disposed around the rotational axis AX.

[0282] The rotor core 31 has a first core 311 and a second core 312. The first core 311 has the front end portion 31F. The second core 312 is disposed at a position further rearward than the first core 311. The first core 311 is substantially cylindrical. The second core 312 is substantially cylindrical. The outer shape of the first core 311 and the outer shape of the second core 312 are the same.

[0283] The first core 311 has a plurality of (eight in the present embodiment) first holes 51 arranged at intervals in the circumferential direction. The second core 312 has a plurality of (eight in the present embodiment) second holes 52 arranged at intervals in the circumferential direction. The number of the first holes 51 and the number of the second holes 52 are equal.

[0284] The plurality of first holes 51 are arranged at intervals in the circumferential direction. In a plane orthogonal to the rotational axis AX, the shapes of the plurality of first holes 51 are the same. In the plane orthogonal to the rotational axis AX, the sizes of the plurality of first holes 51 are equal.

[0285] The plurality of second holes 52 are arranged at equal intervals in the circumferential direction. In a plane orthogonal to the rotational axis AX, the shapes of the plurality of second holes 52 are the same. In the plane orthogonal to the rotational axis AX, the sizes of the plurality of second holes 52 are equal.

[0286] The permanent magnets 33 are respectively disposed to the first holes 51 and the second holes 52. The plurality of (eight in the present embodiment) permanent magnets 33 are disposed around the rotational axis AX. The permanent magnets 33 are plate-shaped. The permanent magnets 33 are cuboid-shaped. The permanent magnets 33 are long in the axial direction.

[0287] The first core 311 and the second core 312 are connected in a manner that at least a portion of one first hole 51 and one second hole 52 overlap. One magnet hole 50 is constituted by the first hole 51 and the second hole 52 overlapping at least a portion of the first hole 51. In the present embodiment, eight magnet holes 50 are provided on the rotor core 31. One permanent magnet 33 is respectively provided in each of the plurality of magnet holes 50.

[0288] In the first core 311, a first portion 61 of the first core 311 is disposed between the circumferentially adjacent first holes 51.

[0289] The plurality of first portions 61 are arranged equidistantly in the circumferential direction. In the circumferential direction, the sizes W1 of the plurality of first portions 61 are equal.

[0290] In the radial direction, the distance C1 from the rotation axis AX to each of the plurality of first portions 61 is equal.

[0291] In the second core 312, the second portions 62 of the second core 312 are arranged between circumferentially adjacent second holes 52.

[0292] The plurality of second portions 62 are arranged equidistantly in the circumferential direction. In the circumferential direction, the sizes W2 of the plurality of second portions 62 are equal.

[0293] In the radial direction, the distance C2 from the rotation axis AX to each of the plurality of second portions 62 is equal.

[0294] The number of first portions 61 and the number of second portions 62 are equal. In the present embodiment, eight first portions 61 are arranged in the circumferential direction. Eight second portions 62 are arranged in the circumferential direction.

[0295] In the circumferential direction, the size W1 of the first portion 61 is smaller than the size W2 of the second portion 62.

[0296] The size W1 of the first portion 61 is equal to or greater than 0.2 mm and equal to or less than 1.0 mm. The size W2 of the second portion 62 is equal to or greater than 2.0 mm and equal to or less than 10.0 mm.

[0297] In the radial direction, the distance C1 from the rotation axis AX to the first portion 61 and the distance C2 from the rotation axis AC to the second portion 62 are equal.

[0298] The first gap 71 is formed between the surface of the permanent magnet 33 arranged in the first hole 51 and at least a portion of the inner surface of the first hole 51. The first resin 73 is arranged in the first gap 71.

[0299] The second gap 72 is formed between the surface of the permanent magnet 33 arranged in the second hole 52 and at least a portion of the inner surface of the second hole 52. The second resin 74 is arranged in the second gap 72.

[0300] The permanent magnet 33 has a first permanent magnet 331 and a second permanent magnet 332. The S pole of the first permanent magnet 331 faces the radially outer side. The N pole of the second permanent magnet 332 faces the radially outer side. In the circumferential direction, the first permanent magnet 331 and the second permanent magnet 332 are arranged alternately. The permanent magnet 33 has four first permanent magnets 331 and four second permanent magnets 332.

[0301] In the present embodiment, the through hole 19 is formed in the rotor core 31. The through hole 19 penetrates the front surface 311F of the first core 311 and the rear surface 312R of the second core 312. In the radial direction, the through hole 19 is formed between the opening 37 of the first core 311 and the outer surface 311S. In the radial direction, the through hole 19 is formed between the opening 38 of the second core 312 and the outer surface 312S. Four through holes 19 are formed around the rotational axis AX. In a plane orthogonal to the rotational axis AX, the through hole 19 is circular arc-shaped. The rotor core 31 is lightened by the through hole 19.

[0302] As shown in FIG. 1, the first hole 51 has a first supporting surface 51A, a second supporting surface 51B, a third supporting surface 51E, a fourth supporting surface 51F, a first extending surface 51G, a first facing surface 51H, a first connecting surface 51I, a second extending surface 51J, a second facing surface 51K, and a second connecting surface 51L. Figure 30 The first supporting surface 51A faces the radially outer side. The first supporting surface 51A is parallel to a tangent line of an imaginary circle centered on the rotational axis AX. The first supporting surface 51A faces the inner surface 33A of the permanent magnet 33.

[0303] The second supporting surface 51B faces the radially inner side. The second supporting surface 51B is parallel to a tangent line of an imaginary circle centered on the rotational axis AX. The second supporting surface 51B faces the outer surface 33B of the permanent magnet 33.

[0304] The third supporting surface 51E faces the other side in the tangent direction. The third supporting surface 51E is connected to an end portion on the one side in the tangent direction of the second supporting surface 51B. The third supporting surface 51E faces a portion on the radially inner side of the first side surface 33E of the permanent magnet 33.

[0305] The fourth supporting surface 51F faces the one side in the tangent direction. The fourth supporting surface 51F is connected to an end portion on the other side in the tangent direction of the second supporting surface 51B. The fourth supporting surface 51F faces a portion on the radially inner side of the second side surface 33F of the permanent magnet 33.

[0306] The permanent magnet 33 is supported by the first supporting surface 51A, the second supporting surface 51B, the third supporting surface 51E, and the fourth supporting surface 51F.

[0307] The first extending surface 51G faces the radially inner side. The first extending surface 51G extends from the end portion of the second supporting surface 51B to the one side in the tangent direction.

[0308] The first facing surface 51H faces the radially outer side. The first facing surface 51H faces at least a portion of the first extending surface 51G. The first facing surface 51H is connected to an end portion on the radially outer side of the third supporting surface 51E.

[0309] The second extending surface 51J faces the radially inner side. The second extending surface 51J is connected to an end portion on the radially outer side of the fourth supporting surface 51F. The second extending surface 51J faces a portion on the radially inner side of the second side surface 33F of the permanent magnet 33.

[0310] The first connecting surface 51I connects the end of the first extending surface 51G on the tangential direction side and the end of the first opposing surface 51H on the tangential direction side.

[0311] The second extension surface 51J faces radially inward. The second extension surface 51J extends from the end of the second support surface 51B to the other side in the tangential direction.

[0312] The second facing surface 51K faces radially outward. The second facing surface 51K faces at least a portion of the second extending surface 51J. The second facing surface 51K is connected to the radially outward end of the fourth support surface 51F.

[0313] The second connecting surface 51L connects the end on the other side of the tangential direction of the second extending surface 51J and the end on the other side of the tangential direction of the second opposing surface 51K.

[0314] In one of the first holes 51, a first gap 71 is formed between the first side surface 33E, the first extension surface 51G, the first opposing surface 51H, and the first connecting surface 51I of the permanent magnet 33. The other first gap 71 is formed between the second side surface 33F, the second extension surface 51J, the second opposing surface 51K, and the second connecting surface 51L of the permanent magnet 33.

[0315] By distributing the first resin 73 in the first gap 71, movement of the permanent magnet 33 inside the magnet hole 50 is suppressed. Alternatively, the first resin 73 can be disposed between the outer surface 33B of the permanent magnet 33 and the second support surface 51B of the first hole 51. Accordingly, the permanent magnet 33 is securely fixed to the rotor core 31. Alternatively, the first resin 73 can be disposed between the first side surface 33E and the third support surface 51E. The first resin 73 can also be disposed between the second side surface 33F and the fourth support surface 51F.

[0316] like Figure 31 As shown, the inner surface of the second hole 52 has a fifth support surface 52A, a sixth support surface 52B, a seventh support surface 52E, an eighth support surface 52F, a third extension surface 52H, a third opposing surface 52G, a third connecting surface 52I, a fourth extension surface 52K, a fourth opposing surface 52J, and a fourth connecting surface 52L.

[0317] The fifth support surface 52A faces radially outward. The fifth support surface 52A is parallel to the tangent of the imaginary circle centered on the axis of rotation AX. The fifth support surface 52A faces the inner surface 33A of the permanent magnet 33.

[0318] The sixth support surface 52B faces radially inward. The sixth support surface 52B is parallel to the tangent of the imaginary circle centered on the axis of rotation AX. The sixth support surface 52B faces the outer surface 33B of the permanent magnet 33.

[0319] The 7th support surface 52E faces the tangential direction other side. The 7th support surface 52E is connected to the tangential direction one side end portion of the 5th support surface 52A. The 7th support surface 52E faces a portion of the radial direction inside of the 1st side surface 33E of the permanent magnet 33.

[0320] The 8th support surface 52F faces the tangential direction one side. The 8th support surface 52F is connected to the tangential direction other side end portion of the 5th support surface 52A. The 8th support surface 52F faces a portion of the radial direction inside of the 2nd side surface 33F of the permanent magnet 33.

[0321] The permanent magnet 33 is supported by the 5th support surface 52A, the 6th support surface 52B, the 7th support surface 52E, and the 8th support surface 52F.

[0322] The 3rd extension surface 52H faces the radial direction inside. The 3rd extension surface 52H extends from the end portion of the 6th support surface 52B to the tangential direction one side.

[0323] The 3rd facing surface 52G faces the radial direction outside. The 3rd facing surface 52G faces at least a portion of the 3rd extension surface 52H. The 3rd facing surface 52G is connected to the radial direction outside end portion of the 7th support surface 52E.

[0324] The 3rd connecting surface 52I connects the tangential direction one side end portion of the 3rd extension surface 52H and the tangential direction one side end portion of the 3rd facing surface 52G.

[0325] The 4th extension surface 52K faces the radial direction inside. The 4th extension surface 52K extends from the end portion of the 6th support surface 52B to the tangential direction other side.

[0326] The 4th facing surface 52J faces the radial direction outside. The 4th facing surface 52J faces at least a portion of the 4th extension surface 52K. The 4th facing surface 52J is connected to the radial direction outside end portion of the 8th support surface 52F.

[0327] The 4th connecting surface 52L connects the tangential direction other side end portion of the 4th extension surface 52K and the tangential direction other side end portion of the 4th facing surface 52J.

[0328] In one of the 2nd holes 52, one of the 2nd voids 72 is formed between the 1st side surface 33E of the permanent magnet 33, the 3rd extension surface 52H, the 3rd facing surface 52G, and the 3rd connecting surface 52I. The other of the 2nd voids 72 is formed between the 2nd side surface 33F of the permanent magnet 33, the 4th extension surface 52K, the 4th facing surface 52J, and the 4th connecting surface 52L.

[0329] By providing the second resin 74 in the second gap 72, movement of the permanent magnet 33 inside the magnet hole 50 is suppressed. In addition, the second resin 74 can also be provided between the outer surface 33B of the permanent magnet 33 and the sixth support surface 52B of the second hole 52. In this way, the permanent magnet 33 is firmly fixed to the rotor core 31. In addition, the second resin 74 can also be provided between the first side surface 33E and the seventh support surface 52E. The first resin 73 can also be provided between the second side surface 33F and the eighth support surface 52F.

[0330] In the tangential direction, the size El of the first hole 51 is larger than the size E2 of the second hole 52.

[0331] In the radial direction, the size Hl of the first hole 51 and the size H2 of the second hole 52 are equal.

[0332] The first core 311 and the second core 312 are connected in a manner in which the center of the first hole 51 and the center of the second hole 52 coincide in the tangential direction or the circumferential direction. The first core 311 and the second core 312 are connected in a manner in which the center of the first hole 51 and the center of the second hole 52 coincide in the radial direction.

[0333] In the state in which the first core 311 and the second core 312 are connected, the first support surface 51A and the fifth support surface 52A are connected, and the second support surface 51B and the sixth support surface 52B are connected. The first support surface 51A and the fifth support surface 52A are coplanar. The second support surface 51B and the sixth support surface 52B are coplanar.

[0334] In the state in which the first core 311 and the second core 312 are connected, the third support surface 51E and the seventh support surface 52E are connected, and the fourth support surface 51F and the eighth support surface 52F are connected. The third support surface 51E and the seventh support surface 52E are coplanar. The fourth support surface 51F and the eighth support surface 52F are coplanar. In the state in which the first core 311 and the second core 312 are connected, at least a portion of the first gap 71 and the second gap 72 overlap.

[0335] As explained above, even in the case in which the rotor core 31 supports eight permanent magnets 33, it is possible to suppress a decrease in detection accuracy of the rotation of the rotor 301 while suppressing a shortage of reluctance torque.

[0336] [Third Embodiment]

[0337] The third embodiment will be explained. In the following explanation, the same reference numerals are attached to structural elements that are the same as or equivalent to those of the above-described embodiments, and the explanation thereof is simplified or omitted.

[0338] <Commonalization of Stator>

[0339] Figure 31 is a diagram schematically showing the relationship between the stator 200 and the rotors 300 of the present embodiment. The stator 200 is the same as the stator 20 explained in the above-described first embodiment, which has a stator core 21 having six tooth portions 21T and six coils 24 wound around the six tooth portions 21T of the stator core 21, respectively.

[0340] As shown in Figure 31 , the stator 200 can be combined with a plurality of rotors 300. The combination of the stator and the rotors means that the rotors can rotate relative to the stator by the excitation of the coils (tooth portions) of the stator. In the example shown in Figure 32 , the rotors 300 that can be combined with the stator 200 include a first rotor 3001 and a second rotor 3002.

[0341] The first rotor 3001 is the same as the rotor 301 explained in the above-described first embodiment, which has four magnet holes 50 and four permanent magnets 33 arranged in the four magnet holes 50, respectively. The second rotor 3002 is the same as the rotor 302 explained in the above-described second embodiment, which has eight magnet holes 50 and eight permanent magnets 33 arranged in the eight magnet holes 50, respectively.

[0342] The outer diameter of the first rotor 3001 is equal to the outer diameter of the second rotor 3002. The outer diameter of the first rotor 3001 is the outer diameter of the rotor core 31 of the first rotor 3001. The outer diameter of the second rotor 3002 is the outer diameter of the rotor core 31 of the second rotor 3002.

[0343] In the axial direction, the size of the first rotor 3001 is equal to the size of the second rotor 3002. The size of the first rotor 3001 in the axial direction is the size of the rotor core 31 of the first rotor 3001 in the axial direction. The size of the second rotor 3002 in the axial direction is the size of the rotor core 31 of the second rotor 3002 in the axial direction.

[0344] The number of poles of the first rotor 3001 is different from the number of poles of the second rotor 3002. The number of poles of the first rotor 3001 is four. The number of poles of the second rotor 3002 is eight. The first rotor 3001 can be combined with the stator 200. The second rotor 3002 can also be combined with the stator 200. The first rotor 3001 can rotate by the rotating magnetic field of the stator 200 in a state of being arranged inside the stator 200. The second rotor 3002 can also rotate by the rotating magnetic field of the stator 200 in a state of being arranged inside the stator 200.

[0345] <Power tool set>

[0346] Figure 33is a diagram schematically showing an electric power tool set 1000 of the present embodiment. The electric power tool set 1000 includes an electric power tool 1 and an electric power tool 101. The electric power tool 1 is an impact driver as one of electric power tools described in the above-described first embodiment. The electric power tool 101 is a chain saw as one of garden tools described in the above-described second embodiment.

[0347] The electric power tool 1 has a first motor 6001. The first motor 6001 is the same as the motor 601 described in the above-described first embodiment. The first motor 6001 has the stator 200 and a first rotor 3001 combined with the stator 200.

[0348] The electric power tool 101 has a second motor 6002. The second motor 6002 is the same as the motor 602 described in the above-described second embodiment. The second motor 6002 has the stator 200 and a second rotor 3002 combined with the stator 200.

[0349] The number of poles of the first rotor 3001 is set according to an output condition required for a first output portion 701 of the first motor 6001. The number of poles of the second rotor 3002 is set according to an output condition required for a second output portion 702 of the second motor 6002. The first output portion 701 of the first motor 6001 includes the rotor shaft 32 of the first rotor 3001. The second output portion 702 of the second motor 6002 includes the rotor shaft 32 of the second rotor 3002.

[0350] The output condition of the first output portion 701 includes a rotational speed of the first output portion 701. The output condition of the second output portion 702 includes a rotational speed of the second output portion 702.

[0351] In a case where the rotational speed required for the first output portion 701 of the first motor 6001 is higher than the rotational speed required for the second output portion 702 of the second motor 6002, the number of poles of the first rotor 3001 is set to a value smaller than the number of poles of the second rotor 3002. In a case where the rotational speed required for the first output portion 701 of the first motor 6001 is lower than the rotational speed required for the second output portion 702 of the second motor 6002, the number of poles of the first rotor 3001 is set to a value larger than the number of poles of the second rotor 3002.

[0352] In the present embodiment, the rotational speed required for the first output portion 701 of the first motor 6001 is higher than the rotational speed required for the second output portion 702 of the second motor 6002. Therefore, the number of poles of the first rotor 3001 is smaller than the number of poles of the second rotor 3002. That is, as described above, the number of poles of the first rotor 3001 is set to 4, and the number of poles of the second rotor 3002 is set to 8.

[0353] Figure 33is a graph showing the relationship of the number of poles of the rotor 300 of the embodiment, the driving current supplied to the coil 24, and the rotational speed of the output portion (the first output portion 701 and the second output portion 702) of the rotor 300.

[0354] In Figure 33 , the line Lc shows the relationship of the driving current and the rotational speed of the first motor 6001 having the first rotor 3001 with the number of poles of 4. The line Ld shows the relationship of the driving current and the rotational speed of the second motor 6002 having the second rotor 3002 with the number of poles of 8. As Figure 34 indicated, in the case where a prescribed driving current is supplied to the coil 24, the rotational speed of the first output portion 701 of the first motor 6001 with the number of poles of 4 is higher than the rotational speed of the second output portion 702 of the second motor 6002 with the number of poles of 8.

[0355] In addition, the output condition of the first output portion 701 can also include the torque of the first output portion 701. The output condition of the second output portion 702 can also include the torque of the second output portion 702.

[0356] In the case where the torque required for the first output portion 701 of the first motor 6001 is higher than the torque required for the second output portion 702 of the second motor 6002, the number of poles of the first rotor 3001 is set to a value larger than the number of poles of the second rotor 3002. In the case where the torque required for the first output portion 701 of the first motor 6001 is lower than the torque required for the second output portion 702 of the second motor 6002, the number of poles of the first rotor 3001 is set to a value smaller than the number of poles of the second rotor 3002.

[0357] In the embodiment, the torque required for the first output portion 701 of the first motor 6001 is lower than the torque required for the second output portion 702 of the second motor 6002. Therefore, the number of poles of the first rotor 3001 is smaller than the number of poles of the second rotor 3002. That is, as described above, the number of poles of the first rotor 3001 is set to 4, and the number of poles of the second rotor 3002 is set to 8.

[0358] In addition, the number of tooth portions 21T of the stator 200 (the number of coils 24) can also not be six.

[0359] Figure 34 is a graph showing the relationship of the number of tooth portions 21T of the stator 200 of the embodiment and the number of poles of the rotor 300 that can be combined with the stator 200. The number of tooth portions 21T is equal to the number of coils 24. As Figure 35 indicated, when the number of tooth portions 21T is set to T, and when a natural number is set to N, the stator core 21 of the stator 200 satisfies the condition T = 3 x N. The number of poles of the rotor 300 that can be combined with the stator 200 is an even number.

[0360] In a case where the stator core 21 of the stator 200 satisfies the condition T = 3 x N and the natural number N is 1, that is, in a case where the number T of the tooth portions 21T of the stator 200 is 3 (= 3 x N), the number of poles of the rotor 300 that can be combined with the stator 200 is 2 (= 2 x N) and 4 (= 4 x N). In a case where the number T of the tooth portions 21T is 3, when the number of poles of the first rotor 3001 is set to any one of 2 and 4, the number of poles of the second rotor 3002 is set to the number of poles different from the number of poles of the first rotor 3001 among 2 and 4. For example, in a case where the required rotation speed of the first output portion 701 is higher than the required rotation speed of the second output portion 702, the number of poles of the first rotor 3001 is set to 2, and the number of poles of the second rotor 3002 is set to 4.

[0361] In a case where the stator core 21 of the stator 200 satisfies the condition T = 3 x N and the natural number N is 2, that is, in a case where the number T of the tooth portions 21T of the stator 200 is 6 (= 3 x N), the number of poles of the rotor 300 that can be combined with the stator 200 is 4 (= 2 x N) and 8 (= 4 x N). In a case where the number T of the tooth portions 21T is 6, when the number of poles of the first rotor 3001 is set to any one of 4 and 8, the number of poles of the second rotor 3002 is set to the number of poles different from the number of poles of the first rotor 3001 among 4 and 8. For example, in a case where the required rotation speed of the first output portion 701 is higher than the required rotation speed of the second output portion 702, the number of poles of the first rotor 3001 is set to 4, and the number of poles of the second rotor 3002 is set to 8.

[0362] In a case where the stator core 21 of the stator 200 satisfies the condition T = 3 x 3 x N and the natural number N is 1, that is, in a case where the number T of the tooth portions 21T of the stator 200 is 9 (= 3 x 3 x N), the number of poles of the rotor 300 that can be combined with the stator 200 is 6 (= 6 x N), 8 (= 8 x N), 10 (= 10 x N), and 12 (= 12 x N). In a case where the number T of the tooth portions 21T is 9, when the number of poles of the first rotor 3001 is set to any one of 6, 8, 10, and 12, the number of poles of the second rotor 3002 is set to the number of poles different from the number of poles of the first rotor 3001 among 6, 8, 10, and 12. For example, in a case where the required rotation speed of the first output portion 701 is higher than the required rotation speed of the second output portion 702, the number of poles of the first rotor 3001 is set to 6, and the number of poles of the second rotor 3002 is set to any one of 8, 10, and 12.

[0363] In a case where the stator core 21 of the stator 200 satisfies the condition T = 3 x 4 x N and the natural number N is 1, that is, in a case where the number T of the tooth portions 21T of the stator 200 is 12 (= 3 x 4 x N), the number of poles of the rotor 300 that can be combined with the stator 200 is 8 (8 x N), 10 (= 10 x N), 14 (= 14 x N), and 16 (= 16 x N). In a case where the number T of the tooth portions 21T is 12, when the number of poles of the first rotor 3001 is set to any one of 8, 10, 14, and 16, the number of poles of the second rotor 3002 is set to a number of poles different from the number of poles of the first rotor 3001 among 8, 10, 14, and 16. For example, in a case where the required rotation speed of the first output portion 701 is higher than the required rotation speed of the second output portion 702, the number of poles of the first rotor 3001 is set to 8, and the number of poles of the second rotor 3002 is set to any one of 10, 14, and 16.

[0364] In a case where the stator core 21 of the stator 200 satisfies the condition T = 3 x 5 x N and the natural number N is 1, that is, in a case where the number T of the tooth portions 21T of the stator 200 is 15 (= 3 x 5 x N), the number of poles of the rotor 300 that can be combined with the stator 200 is 10 (10 x N), 14 (= 14 x N), 16 (= 16 x N), and 20 (= 20 x N). In a case where the number T of the tooth portions 21T is 15, when the number of poles of the first rotor 3001 is set to any one of 10, 14, 16, and 20, the number of poles of the second rotor 3002 is set to a number of poles different from the number of poles of the first rotor 3001 among 10, 14, 16, and 20. For example, in a case where the required rotation speed of the first output portion 701 is higher than the required rotation speed of the second output portion 702, the number of poles of the first rotor 3001 is set to 10, and the number of poles of the second rotor 3002 is set to any one of 14, 16, and 20.

[0365] In a case where the stator core 21 of the stator 200 satisfies the condition T = 3 x 3 x N and the natural number N is 2, that is, in a case where the number T of the tooth portions 21T of the stator 200 is 18 (= 3 x 3 x N), the number of poles of the rotor 300 that can be combined with the stator 200 is 12 (= 6 x N), 16 (= 8 x N), 20 (= 10 x N), and 24 (= 12 x N). In a case where the number T of the tooth portions 21T is 18, when the number of poles of the first rotor 3001 is set to any one of 12, 16, 20, and 24, the number of poles of the second rotor 3002 is set to a number of poles different from the number of poles of the first rotor 3001 among 12, 16, 20, and 24. For example, in a case where the required rotation speed of the first output portion 701 is higher than the required rotation speed of the second output portion 702, the number of poles of the first rotor 3001 is set to 12, and the number of poles of the second rotor 3002 is set to any one of 16, 20, and 24.

[0366] In a case where the stator core 21 of the stator 200 satisfies the condition T = 3 x N and the natural number N is 7, that is, in a case where the number T of the tooth portions 21T of the stator 200 is 21 (= 3 x N), the number of poles of the rotor 300 that can be combined with the stator 200 is 14 (= 2 x N) and 28 (= 4 x N). In a case where the number T of the tooth portions 21T is 21, when the number of poles of the first rotor 3001 is set to any one of 14 and 28, the number of poles of the second rotor 3002 is set to the number of poles different from the number of poles of the first rotor 3001 among 14 and 28. For example, in a case where the required rotation speed of the first output portion 701 is higher than the required rotation speed of the second output portion 702, the number of poles of the first rotor 3001 is set to 14, and the number of poles of the second rotor 3002 is set to 28.

[0367] In a case where the stator core 21 of the stator 200 satisfies the condition T = 3 x 4 x N and the natural number N is 2, that is, in a case where the number T of the tooth portions 21T of the stator 200 is 24 (= 3 x 4 x N), the number of poles of the rotor 300 that can be combined with the stator 200 is 16 (8 x N), 20 (= 10 x N), 28 (= 14 x N), and 32 (= 16 x N). In a case where the number T of the tooth portions 21T is 24, when the number of poles of the first rotor 3001 is set to any one of 16, 20, 28, and 32, the number of poles of the second rotor 3002 is set to the number of poles different from the number of poles of the first rotor 3001 among 16, 20, 28, and 32. For example, in a case where the required rotation speed of the first output portion 701 is higher than the required rotation speed of the second output portion 702, the number of poles of the first rotor 3001 is set to 16, and the number of poles of the second rotor 3002 is set to any one of 20, 28, and 32.

[0368] As described above, according to the present embodiment, it is possible to combine a plurality of rotors 300 with one stator 20. Therefore, the production cost of the first electric machine 6001 and the second electric machine 6002 is suppressed. For example, it is possible to share the production equipment of the first electric machine 6001 and the production equipment of the second electric machine 6002. By suppressing the production cost of the first electric machine 6001 and the second electric machine 6002, the production cost of the electric working machine 1 and the electric working machine 101 is suppressed. In addition, without producing different electric machines depending on the type of the electric working machine, the first electric machine 6001 and the second electric machine 6002 can also satisfy the required output characteristics, respectively, by only changing the rotor 300 combined with the stator 20.

[0369] The outer diameter of the first rotor 3001 is equal to the outer diameter of the second rotor 3002. Accordingly, the first rotor 3001 and the second rotor 3002 can each smoothly rotate in a state of being disposed inside the stator 20.

[0370] The number of poles of the first rotor 3001 is set based on the output conditions required by the first output unit 701 of the first motor 6001. By combining any one of the various rotors 300 with different numbers of poles as the first rotor 3001 into a stator 20, the first output unit 701 can output according to the required output conditions.

[0371] <Another embodiment>

[0372] Figure 35 This diagram schematically illustrates the relationship between the stator 200 and the rotor 300 in another embodiment of this invention. In the above embodiment, a single stator 200 is combined with multiple rotors 300. It is also possible to combine multiple stators 200 and multiple rotors 300.

[0373] like Figure 7 As shown, stator 200 includes a first stator 201 and a second stator 202. The first motor 6001 of the electric work machine 1 has a first stator 201 and a first rotor 3001 combined with the first stator 201. The first stator 201 includes a first stator core 211 and a plurality of first coils 241 respectively wound around a plurality of teeth 21T of the first stator core 211. The controller 9 of the electric work machine 1 supplies drive current to the first coils 241 of the first stator 201 to excite the teeth 21T of the first stator core 211, causing the first rotor 3001 to rotate around the rotation axis AX.

[0374] The structure of the first stator 201 is the same as that of a part of the second stator 202. The structure of the first stator 201 is different from that of another part of the second stator 202.

[0375] In a plane orthogonal to the rotation axis AX, the shape of the first stator core 211 is the same as the shape of the second stator core 212 of the second stator 202 used by the second motor 6002 of another electric work machine 101. The first rotor 3001 can be combined with the second stator 202.

[0376] The length of the first stator core 211, which represents the axial dimension, is different from the length of the second stator core 212.

[0377] The length of the first stator core 211 is set based on the output conditions required by the first output section 701 of the first motor 6001. The length of the second stator core 212 is set based on the output conditions required by the second output section 702 of the second motor 6002.

[0378] The output conditions of the first output unit 701 include the rotational speed of the first output unit 701. The output conditions of the second output unit 702 include the rotational speed of the second output unit 702.

[0379] In a case where the required rotational speed of the first output portion 701 of the first motor 6001 is higher than the required rotational speed of the second output portion 702 of the second motor 6002, the length of the first stator core 211 is set to a value shorter than the length of the second stator core 212. In a case where the required rotational speed of the first output portion 701 of the first motor 6001 is lower than the required rotational speed of the second output portion 702 of the second motor 6002, the length of the first stator core 211 is set to a value longer than the length of the second stator core 212.

[0380] In the present embodiment, the required rotational speed of the first output portion 701 of the first motor 6001 is higher than the required rotational speed of the second output portion 702 of the second motor 6002. Therefore, the length of the first stator core 211 is shorter than the length of the second stator core 212.

[0381] In addition, the output condition of the first output portion 701 can also include the torque of the first output portion 701. The output condition of the second output portion 702 can also include the torque of the second output portion 702.

[0382] In a case where the required torque of the first output portion 701 of the first motor 6001 is higher than the required torque of the second output portion 702 of the second motor 6002, the length of the first stator core 211 is set to a value longer than the length of the second stator core 212. In a case where the required torque of the first output portion 701 of the first motor 6001 is lower than the required torque of the second output portion 702 of the second motor 6002, the length of the first stator core 211 is set to a value shorter than the length of the second stator core 212.

[0383] In the present embodiment, the required torque of the first output portion 701 of the first motor 6001 is lower than the required torque of the second output portion 702 of the second motor 6002. Therefore, the length of the first stator core 211 is shorter than the length of the second stator core 212.

[0384] The second stator 202 has a plurality of second coils 242 wound around a plurality of tooth portions 21T of the second stator core 212, respectively. The number of tooth portions 21T of the first stator 201 and the number of tooth portions 21T of the second stator 202 are equal. The number of first coils 241 of the first stator 201 (six in the present embodiment) and the number of second coils 242 of the second stator 202 (six in the present embodiment) are equal.

[0385] The connection mode of the first coils 241 is the same as the connection mode of the second coils 242. In a case where the connection mode of the first coils 241 is the delta connection described above, the connection mode of the second coils 242 is also the delta connection. Figure 36

[0386] ​The wire diameter of the first coil 241 is equal to the wire diameter of the second coil 242. The wire diameter of the first coil 241 refers to the thickness (diameter) of the wire forming the first coil 241. The wire diameter of the second coil 242 refers to the thickness (diameter) of the wire forming the second coil 242.

[0387] The number of turns of the first coil 241 is equal to the number of turns of the second coil 242. The number of turns of the first coil 241 refers to the number of turns of the wire forming the first coil 241 around the tooth portion 21T of the first stator core 211. The number of turns of the second coil 242 refers to the number of turns of the wire forming the second coil 242 around the tooth portion 21T of the second stator core 212.

[0388] Figure 36 is a flowchart showing a manufacturing method of the electric power tool set 1000 according to another embodiment of the present embodiment. In Figure 31 The first electric power tool refers to the electric power tool 1 described above. The second electric power tool refers to the electric power tool 101 described above.

[0389] The first motor 6001 is manufactured in the manufacturing of the first electric power tool. In the case where the first motor 6001 is manufactured, the first stator core 211 is manufactured (step SA1). The first stator core 211 is manufactured by laminating a plurality of first steel sheets.

[0390] Next, a plurality of first coils 241 are wound around the plurality of tooth portions 21T of the first stator core 211, respectively. The plurality of first coils 241 are manufactured by being wound around the tooth portions 21T in the first wiring manner (step SA2).

[0391] The first stator 201 is manufactured by winding the first coils 241 around the tooth portions 21T of the first stator core 211. After the first stator 201 is manufactured, the first stator 201 and the first rotor 3001 of the first number of poles are combined. Accordingly, the first motor 6001 is manufactured (step SA3).

[0392] The first electric power tool is manufactured using the first motor 6001.

[0393] The second motor 6002 is manufactured in the manufacturing of the second electric power tool. In the case where the second motor 6002 is manufactured, the second stator core 212 is manufactured. The second stator core 212 is manufactured by laminating a plurality of second steel sheets (step SB1).

[0394] The second steel sheet for manufacturing the second stator core 212 is the same shape and the same size as the first steel sheet for manufacturing the first stator core 211. Accordingly, in a plane orthogonal to the rotational axis AX, the shape and size of the first stator core 211 and the shape and size of the second stator core 212 are the same. The length of the first stator core 211 is adjusted by adjusting the number of layers of the first steel sheet. The length of the second stator core 212 is adjusted by adjusting the number of layers of the second steel sheet.

[0395] Next, a plurality of second coils 242 are wound around the plurality of tooth portions 21T of the second stator core 212, respectively. The plurality of second coils 242 are manufactured by being wound around the tooth portions 21T in a second wiring pattern (step SB2).

[0396] The second wiring pattern for manufacturing the second coil 242 is the same as the first wiring pattern for manufacturing the first coil 241.

[0397] The second stator 202 is manufactured by winding the second coil 242 around the tooth portion 21T of the second stator core 212. After the second stator 202 is manufactured, the second stator 202 and the second rotor 3002 of the second number of poles are combined. Accordingly, the second electric machine 6002 is manufactured (step SB3).

[0398] The second number of poles of the second rotor 3002 and the first number of poles of the first rotor 3001 are different.

[0399] The second electric machine 6002 is used to manufacture a second electric working machine.

[0400] The second rotor 3002 can be combined with the first stator 201. The second rotor 3002 can rotate with respect to the second stator 202, and can rotate with respect to the first stator 20. A third electric machine can also be manufactured by combining the first stator 201 and the second rotor 3002. Similarly, the first rotor 3001 can be combined with the second stator 202. The first rotor 3001 can rotate with respect to the first stator 20, and can rotate with respect to the second stator 202. A fourth electric machine can also be manufactured by combining the second stator 202 and the first rotor 3001 (step SC).

[0401] The third electric machine can also be used in one or both of the first electric working machine and the second electric working machine. The fourth electric machine can also be used in one or both of the first electric working machine and the second electric working machine. The third electric machine can also be used in a third electric working machine different from the first electric working machine and the second electric working machine. The fourth electric machine can also be used in a fourth electric working machine different from the first electric working machine and the second electric working machine.

[0402] As explained above, even if the structure of the first stator 201 and the structure of a part of the second stator 202 are different, since the first rotor 3001 combined with the first stator 201 can be combined with the second stator 202, the production cost of the first motor 6001 and the second motor 6002 can also be suppressed. In a plane orthogonal to the rotational axis AX, the shape of the first stator core 211 and the shape of the second stator core 212 of the second stator 202 are the same. Accordingly, the first rotor 3001 combined with the first stator 201 can be combined with the second stator 202.

[0403] In addition, as explained above with reference to Figure 32 and Figure 7 , the first stator core 211 and the second stator core 212 are the same, that is, by combining one stator core 21 and the first rotor 3001 and the second rotor 3002 respectively, the production cost of the first motor 6001 and the second motor 6002 can be more effectively suppressed.

[0404] In addition, in the present embodiment, the length of the first rotor 3001 indicating the axial direction can also be equal to the length of the second rotor 3002.

[0405] In addition, in the present embodiment, the outer diameter of the first rotor 3001 can also be different from the outer diameter of the second rotor 3002.

[0406] In addition, in the present embodiment, the wire diameter of the first coil 241 and the wire diameter of the second coil 242 can also be different. The number of turns of the first coil 241 and the number of turns of the second coil 242 can also be different.

[0407] In addition, in the present embodiment, the connection method of the first coil 241 and the connection method of the second coil 242 are respectively the parallel triangle connection explained with reference to Figure 7 . The connection method of the first coil 241 and the connection method of the second coil 242 can be the same, and are not limited to the connection method explained with reference to Figures 37-39 .

[0408] Figure 37 are diagrams schematically showing the connection state of the coil 24 (241, 242) of another embodiment of the present embodiment. As shown in Figure 38 , the connection method of the coil 24 (241, 242) can also be the series triangle connection. As shown in Figure 39 , the connection method of the coil 24 (241, 242) can also be the parallel Y connection. As shown in Figure 40 , the connection method of the coil 24 (241, 242) can also be the series Y connection.

[0409] In addition, the motor of the embodiment is an interior permanent magnet (IPM) motor. The motor can also be a surface permanent magnet (SPM) motor in which permanent magnets are attached to the outer surface of a rotor core. Alternatively, for example, the first rotor 3001 can be an IPM motor, and the second rotor 3002 can be an SPM motor.

[0410] In addition, the motor of the embodiment is an interior rotor type brushless motor. The motor can also be an exterior rotor type brushless motor.

[0411] [Another Embodiment]

[0412] In addition, in the above-described embodiment, the size Wl of the first portion 61 of the first core 311 is made smaller than the size W2 of the second portion 62 of the second core 312. Thereby, the reluctance torque of the first core 311 with respect to the stator 20 is made smaller than the reluctance torque of the second core 312 with respect to the stator 20. The adjustment of the reluctance torque of the first core 311 and the adjustment of the reluctance torque of the second core 312 are not limited to the adjustment of the size Wl and the adjustment of the size W2.

[0413] Figure 41 is a cross-sectional view partially enlarging the first core 311 of another embodiment. Figure 40 is a cross-sectional view partially enlarging the second core 312 of another embodiment. As with the above-described embodiment, the first core 311 and the second core 312 are adjacent in the axial direction. As shown in Figure 41 The first core 311 has a plurality of first holes 51 arranged at intervals in the circumferential direction. As shown in Figure 40 The second core 312 has a plurality of second holes 52 arranged at intervals in the circumferential direction. The permanent magnets 33 are respectively arranged in the first holes 51 and the second holes 52. The first portion 61 of the first core 311 is arranged between the first holes 51 adjacent in the circumferential direction. The second portion 62 of the second core 312 is arranged between the second holes 52 adjacent in the circumferential direction. In the circumferential direction, the size Wl of the first portion 61 is equal to the size W2 of the second portion 62. As shown in Figure 41 A hole 63 is formed in the first portion 61. As shown in ​ No hole is formed in the second portion 62. By forming the hole 63 in the first portion 61, the reluctance torque of the first core 311 with respect to the stator 20 is made smaller than the reluctance torque of the second core 312 with respect to the stator 20.

[0414] In addition, the electric power tool 1 of the above-described embodiment is an impact driver as one of electric power tools. The electric power tool is not limited to the impact driver. The electric power tool can be, for example, a screwdriver, a vibration screwdriver, an angle drill, a screw drill, an electric hammer, a hammer drill, a circular saw, or a reciprocating saw.

[0415] The electric power tool 101 of the above-described embodiment is a chain saw as one of outdoor power equipment. The outdoor power equipment is not limited to the chain saw. The outdoor power equipment can be, for example, a hedge trimmer, a lawn trimmer, a weeder, and a blower.

[0416] In the above-described embodiment, the electric power tool can also be a cleaner.

[0417] In the above-described embodiment, the power source of the electric power tool uses the battery pack 14 mounted to the battery mounting portion. The power source of the electric power tool can also use a commercial power source (alternating current power source).

[0418] Explanation of Reference Numerals

[0419] 1: electric power tool (impact driver); 2: housing; 2A: motor housing portion; 2B: grip portion; 2C: controller housing portion; 3: rear cover; 4: hammer housing; 5: battery mounting portion; 7: fan; 8: anvil; 8A: insertion hole; 9: controller; 10: trigger switch; 11: forward / reverse switch lever; 12: operation panel; 13: lamp; 14: battery pack; 15: air intake port; 16: air exhaust port; 17: chucking mechanism; 18: screw; 19: through hole; 20: stator; 21: stator core; 21T: tooth portion; 22: front insulator; 22D: threaded hole; 22P: protruding portion; 22S: support portion; 22T: protruding portion; 23: rear insulator; 23T: protruding portion; 24: coil; 24U: U-phase coil; 24U1: U-phase coil; 24U2: U-phase coil; 24V: V-phase coil; 24V1: V-phase coil; 24V2: V-phase coil; 24W: W-phase coil; 24W1: W-phase coil; 24W2: W-phase coil; 25: power supply wire; 25U: U-phase power supply wire; 25V: V-phase power supply wire; 25W: W-phase power supply wire; 26: fuse terminal; 26U: U-phase fuse terminal; 26V: V-phase fuse terminal; 26W: W-phase fuse terminal; 27: short-circuit member; 27A: opening; 27U: U-phase short-circuit member; 27V: V-phase short-circuit member; 27W: W-phase short-circuit member; 28: insulating member; 28A: main body portion; 28B: threaded boss portion; 28C: support portion; 28D: opening; 29: connection wire; 29E: end winding portion; 29S: start winding portion; 31: rotor core; 31F: front end portion (first end portion); 31R: rear end portion (second end portion); 32: rotor shaft; 33: permanent magnet; 33A: inner surface; 33B: outer surface; 33C: front surface; 33D: rear surface; 33E: first side surface; 33F: second side surface; 35: first steel plate; 36: second steel plate; 37: opening; 38: opening; 39A: recess; 39B: recess; 40: sensor substrate; 41: plate portion; 42: threaded boss portion; 43: magnetic sensor; 44: signal wire; 45: opening; 50: magnet hole; 51: first hole; 51A: first support surface; 51B: second support surface; 51E: third support surface; 51F: fourth support surface; 51G: first extension surface; 51H: first facing surface; 51I: first connection surface; 51J: second extension surface; 51K: second facing surface; 51L: second connection surface; 52: second hole; 52A: fifth support surface; 52B: sixth support surface; 52E: seventh support surface; 52F: eighth support surface; 52G: third facing surface; 52H: third extension surface; 52I: third connection surface; 52J: fourth facing surface; 52K: fourth extension surface; 52L: fourth connection surface; 61: first portion; 62: second portion; 63: hole; 71: first gap; 72: second gap; 73: first resin; 74: second resin; 101: electric power tool;102: housing; 103: guard; 104: first grip portion; 105: battery mounting portion; 106: trigger switch; 107: trigger lock lever; 108: guide lever; 109: saw chain; 110: motor housing portion; 111: battery holding portion; 112: second grip portion; 200: stator; 201: first stator; 202: second stator; 211: first stator core; 212: second stator core; 241: first coil; 242: second coil; 300: rotor; 301: rotor; 301B: rotor; 302: rotor; 311: first core; 311F: front surface; 311R: rear surface; 311S: outer surface; 311T: inner surface; 312: second core; 312F: front surface; 312R: rear surface; 312S: outer surface; 312T: inner surface; 313: third core; 331: first permanent magnet; 332: second permanent magnet; 601: motor; 602: motor; 701: first output portion; 702: second output portion; 1000: electric power tool set; 3001: first rotor; 3002: second rotor; 6001: first motor; 6002: second motor; C1: distance; C2: distance; E1: dimension; E2: dimension; H1: dimension; H2: dimension; L1: dimension; L2: dimension; La: line; Lb: line; Lc: line; Ld: line; R1: distance; R2: distance; T1: thickness; T2: thickness; Vn: arrow; Vs: arrow; W1: dimension; W2: dimension.

Claims

1. An electric working machine characterized by comprising a first brushless motor, a second brushless motor, and a controller, wherein the first brushless motor has a first stator and a first rotor, the first stator has a first stator core and a plurality of first coils, the first stator core has a plurality of first tooth portions, the plurality of first coils are respectively wound around each of the plurality of first tooth portions, the first rotor is combined with the first stator, the second brushless motor has a second stator and a second rotor, the second stator is capable of being combined with the first rotor, has a second stator core and a plurality of second coils, the second stator core has a plurality of second tooth portions and has the same shape as the first stator core in a plane orthogonal to a rotational axis, the plurality of second coils are respectively wound around each of the plurality of second tooth portions, the second rotor is combined with the second stator and has a different number of poles from the first rotor, and the controller excites the first tooth portions to rotate the first rotor about the rotational axis.

2. The electric working machine according to claim 1, characterized in that a length of the first stator core, which is a dimension of the first stator core in an axial direction parallel to the rotational axis, is set according to an output condition required for a first output portion of the first brushless motor.

3. The electric working machine according to claim 2, characterized in that the output condition includes a rotational speed of the first output portion, and in a case where the rotational speed required for the first output portion is higher than a rotational speed required for a second output portion of the second brushless motor, the length of the first stator core is set to a value shorter than a length of the second stator core.

4. The electric working machine according to claim 2, characterized in that the output condition includes a torque of the first output portion, and in a case where the torque required for the first output portion is lower than a torque required for a second output portion of the second brushless motor, the length of the first stator core is set to a value shorter than a length of the second stator core.

5. The electric working machine according to claim 1, characterized in that the length of the first stator core, which is a dimension of the first stator core in an axial direction parallel to the rotational axis, is equal to a length of the second stator core, which is a dimension of the second stator core in an axial direction parallel to the rotational axis.

6. The electric working machine according to any one of claims 1 to 5, characterized in that a wiring pattern of the first coils is the same as a wiring pattern of the second coils.

7. The electric working machine according to claim 6, characterized in that a wire diameter and a number of turns of the first coils are equal to a wire diameter and a number of turns of the second coils.

8. The electric working machine according to any one of claims 1 to 5, 7, characterized in that an outer diameter of the first rotor is equal to an outer diameter of the second rotor. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 9. The electrically powered working machine according to any one of claims 1 to 5, 7, wherein the number of poles of the first rotor is set in accordance with an output condition required for a first output portion of the first brushless motor.

10. The electrically powered working machine according to claim 9, wherein the output condition includes a rotational speed of the first output portion, in a case where the rotational speed required for the first output portion is higher than a rotational speed required for a second output portion of the second brushless motor, the number of poles of the first rotor is set to a value smaller than the number of poles of the second rotor.

11. The electrically powered working machine according to claim 9, wherein the output condition includes a torque of the first output portion, in a case where the torque required for the first output portion is lower than a torque required for a second output portion of the second brushless motor, the number of poles of the first rotor is set to a value smaller than the number of poles of the second rotor.

12. The electrically powered working machine according to any one of claims 1 to 5, 7, 10, 11, wherein when the number of the first teeth is set to T and a natural number is set to N, the first stator core satisfies a condition T = 3 x N, and the number of poles of the first rotor is an even number.

13. The electrically powered working machine according to claim 12, wherein the number of poles of the first rotor is any one of 2 x N and 4 x N, the number of poles of the second rotor is any one of 2 x N and 4 x N different from the number of poles of the first rotor.

14. The electrically powered working machine according to claim 12, wherein the first stator core satisfies a condition T = 3 x 3 x N, the number of poles of the first rotor is any one of 6 x N, 8 x N, 10 x N, and 12 x N, the number of poles of the second rotor is any one of 6 x N, 8 x N, 10 x N, and 12 x N different from the number of poles of the first rotor.

15. The electrically powered working machine according to claim 12, wherein the first stator core satisfies a condition T = 3 x 4 x N, the number of poles of the first rotor is any one of 8 x N, 10 x N, 14 x N, and 16 x N, the number of poles of the second rotor is any one of 8 x N, 10 x N, 14 x N, and 16 x N different from the number of poles of the first rotor.

16. The electrically powered working machine according to claim 12, wherein the first stator core satisfies a condition T = 3 x 5 x N, the number of poles of the first rotor is any one of 10 x N, 14 x N, 16 x N, and 20 x N, the number of poles of the second rotor is any one of 10 x N, 14 x N, 16 x N, and 20 x N different from the number of poles of the first rotor.

17. The electrically powered working machine according to claim 12, wherein a plurality of the first coils are respectively assigned to any one of a U phase, a V phase, and a W phase.

18. The electrically powered working machine according to any one of claims 1 to 5, 7, 10, 11, 13 to 17, wherein the first rotor has a rotor core and a permanent magnet, wherein the rotor core has a first core and a second core, the first core has a plurality of teeth, and The first core includes a first end portion and has a plurality of first holes and a first portion, The plurality of first holes are disposed at intervals in a circumferential direction of the rotation axis, The first portion is disposed between the first holes adjacent in the circumferential direction, The second core is adjacent to the first core in an axial direction and has a plurality of second holes and a second portion, The plurality of second holes are disposed at intervals in the circumferential direction; The second portion is disposed between the second holes adjacent in the circumferential direction, In the circumferential direction, the size of the first portion is smaller than the size of the second portion; The permanent magnets are respectively disposed in the first holes and the second holes and are supported by the rotor core, The electric power tool has a magnetic sensor disposed in a position facing the first end portion of the rotor core in an axial direction parallel to the rotation axis, for detecting rotation of the first rotor.

19. The electric power tool according to claim 18, wherein The first core has a plurality of the first portions in the circumferential direction, The second core has a plurality of the second portions in the circumferential direction, In the circumferential direction, the sizes of the plurality of the first portions are equal, In the circumferential direction, the sizes of the plurality of the second portions are equal.

20. A manufacturing method of an electric power tool, comprising: stacking a first steel sheet to manufacture a first stator core, winding a plurality of first coils in a first wiring pattern on a plurality of first teeth of the first stator core to manufacture a first stator, combining the first stator and a first rotor having a first number of poles to manufacture a first brushless motor, stacking a second steel sheet having the same shape as the first steel sheet to manufacture a second stator core, winding a plurality of second coils in a second wiring pattern identical to the first wiring pattern on a plurality of second teeth of the second stator core to manufacture a second stator, combining the second stator and a second rotor having a second number of poles identical to the first number of poles to manufacture a second brushless motor, manufacturing a first electric power tool using the first brushless motor, manufacturing a second electric power tool using the second brushless motor.

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