Electric work machine

Abstract

To appropriately drive an electric working machine.SOLUTION: An electric working machine includes: a motor having a stator, a rotor rotating with respect to the stator, and a rotor shaft fixed to the rotor; an output part driven by the rotor shaft; a moto case for storing the stator and the rotor; a magnet which is arranged inside the motor case and is rotated by the rotor shaft; and a sensor substrate which is arranged inside the motor case, and supports a magnetic sensor for detecting the magnet.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The technology disclosed in this specification relates to an electric working machine.

Background Art

[0002] In the technical field related to electric working machines, an electric tool including a motor and a sensor board, as disclosed in Patent Document 1, is known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The motor has a stator and a rotor that rotates with respect to the stator. The rotation of the rotor is detected by a magnetic sensor supported by the sensor board. The motor is controlled based on the detection signal of the magnetic sensor. If the detection accuracy of the magnetic sensor decreases, there is a possibility that the electric working machine may not be properly driven.

[0005] The technology disclosed in this specification aims to ensure that the electric working machine is properly driven.

Means for Solving the Problems

[0006] This specification discloses an electric work machine. The electric work machine may include a motor and an output unit. The motor may have a stator, a rotor that rotates relative to the stator, and a rotor shaft fixed to the rotor. The output unit may be driven by the rotor shaft. The electric work machine may include a motor case housing the stator and rotor. The electric work machine may include a magnet disposed inside the motor case and rotated by the rotor. The electric work machine may include a magnetic sensor disposed inside the motor case and detecting the magnet. [Effects of the Invention]

[0007] According to the technology disclosed herein, electric work machines are driven properly. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a left-side perspective view showing an electric work machine according to the first embodiment. [Figure 2] Figure 2 is a left-side perspective view showing a motor assembly according to the first embodiment. [Figure 3] Figure 3 is a side view showing a motor assembly according to the first embodiment. [Figure 4] Figure 4 is a longitudinal cross-sectional view showing a motor assembly according to the first embodiment. [Figure 5] Figure 5 is a cross-sectional view showing a motor assembly according to the first embodiment. [Figure 6] Figure 6 is an enlarged longitudinal cross-sectional view of a portion of the motor assembly according to the first embodiment. [Figure 7] Figure 7 is an enlarged longitudinal cross-sectional view of a portion of the motor assembly according to the second embodiment. [Figure 8] Figure 8 is an exploded perspective view showing the sensor substrate and heat insulating plate according to the second embodiment. [Figure 9] Figure 9 is an enlarged longitudinal cross-sectional view of a part of the motor assembly according to the third embodiment. [Figure 10]Figure 10 is a longitudinal cross-sectional view showing a motor assembly according to the fourth embodiment. [Figure 11] Figure 11 is an enlarged longitudinal cross-sectional view of a portion of the motor assembly according to the fourth embodiment. [Figure 12] Figure 12 is an enlarged longitudinal cross-sectional view of a portion of the motor assembly according to the fifth embodiment. [Figure 13] Figure 13 is a left-side perspective view showing the lid according to the fifth embodiment. [Figure 14] Figure 14 is a right-side perspective view showing the lid according to the fifth embodiment. [Modes for carrying out the invention]

[0009] In one or more embodiments, the electric work machine may include a motor and an output unit. The motor may have a stator, a rotor that rotates relative to the stator, and a rotor shaft fixed to the rotor. The output unit may be driven by the rotor shaft. The electric work machine may include a motor case housing the stator and rotor. The electric work machine may include a magnet disposed inside the motor case and rotated by the rotor. The electric work machine may include a magnetic sensor disposed inside the motor case and detecting the magnet.

[0010] In the above configuration, since the magnet is rotated by the rotor, the magnetic sensor can detect the rotation of the rotor by detecting the magnet. Further, since each of the magnet and the magnetic sensor is disposed inside the motor case, it is protected by the motor case. By protecting each of the magnet and the magnetic sensor by the motor case, a decrease in the detection accuracy of the magnetic sensor is suppressed. For example, when the magnet is disposed outside the motor case, there is a possibility that a magnetic material such as iron powder existing around the motor case adheres to the magnet. Further, when the magnetic sensor is disposed outside the motor case, the magnetic sensor may deteriorate. If a magnetic material adheres to the magnet or the magnetic sensor deteriorates, the detection accuracy of the magnetic sensor may decrease. By protecting each of the magnet and the magnetic sensor by the motor case, a decrease in the detection accuracy of the magnetic sensor is suppressed. The motor is controlled based on the detection signal of the magnetic sensor in which a decrease in the detection accuracy is suppressed. Thereby, the electric working machine is properly driven.

[0011] In one or more embodiments, the electric working machine may include a sensor substrate that supports the magnetic sensor.

[0012] In the above configuration, since the sensor substrate is disposed inside the motor case, it is protected by the motor case. By protecting the sensor substrate by the motor case, a decrease in the detection accuracy of the magnetic sensor is suppressed. For example, when the sensor substrate is disposed outside the motor case, the magnetic sensor may deteriorate. By protecting the sensor substrate by the motor case, a decrease in the detection accuracy of the magnetic sensor is suppressed.

[0013] In one or more embodiments, in the axial direction parallel to the rotation axis of the rotor, the sensor substrate may be disposed between at least a part of the motor case and the magnet.

[0014] In the above configuration, an increase in the size of the motor assembly including the motor case, the magnet, and the sensor substrate is suppressed.

[0015] In one or more embodiments, the sensor substrate may be fixed to the motor case.

[0016] In the above configuration, a change in the relative position between the motor case and the sensor substrate is suppressed.

[0017] In one or more embodiments, the motor case may include a main body portion having an opening and accommodating a stator and a rotor, and a lid portion fixed to the main body portion so as to close the opening. The sensor substrate may be fixed to the lid portion.

[0018] In the above configuration, with the sensor substrate fixed to the lid portion and the lid portion fixed to the main body portion, the sensor substrate is disposed inside the motor case.

[0019] In one or more embodiments, the sensor substrate may be made of metal or heat-dissipating resin.

[0020] In the above configuration, since the sensor substrate is formed of a material that easily dissipates heat, even if the heat of the rotor is transmitted to the sensor substrate, an increase in the temperature of the sensor substrate is suppressed. Further, since the sensor substrate is connected to the motor case, the heat of the sensor substrate is transmitted to the motor case and dissipated around the motor case. Therefore, the magnetic sensor can operate properly.

[0021] In one or more embodiments, the electric working machine may include a rotating member fixed to the rotor shaft inside the motor case. The magnet detected by the magnetic sensor may be a sensor magnet fixed to the rotating member.

[0022] In the above configuration, the sensor magnet fixed to the rotating member is detected by a magnetic sensor, thus suppressing the effect of rotor heat on the magnetic sensor. The rotor may become hot when the motor is driven, potentially generating heat. If the rotor magnet is detected by a magnetic sensor, it may be necessary to place the sensor substrate close to the rotor. If the sensor substrate is placed close to the rotor, the heat from the rotor may prevent the magnetic sensor from functioning properly. The rotating member is unlikely to become hot. Therefore, if the sensor magnet is detected by a magnetic sensor, the magnetic sensor can function properly even if the sensor substrate is placed close to the rotating member. Furthermore, since both the rotating member and the rotor are located inside the motor case, the sensor magnet and rotor magnet can be magnetized simultaneously during their production. That is, with both the rotating member and the rotor fixed to the rotor shaft, the rotating member and the rotor can be simultaneously fed into the magnetization device. Therefore, misalignment between the sensor magnet and the rotor magnet in the rotational direction is suppressed. As a result, the motor is properly controlled based on the detection signal from the magnetic sensor that detected the sensor magnet.

[0023] In one or more embodiments, the rotating member may be positioned between the magnetic sensor and the rotor in an axial direction parallel to the rotor's axis of rotation.

[0024] In the above configuration, the distance between the magnetic sensor and the rotor is increased. Therefore, the effect of the rotor's heat on the magnetic sensor is suppressed. In addition, since a rotating member is placed between the magnetic sensor and the rotor, the radiant heat from the rotor is blocked by the rotating member and its transmission to the magnetic sensor is suppressed. As a result, the magnetic sensor can operate properly.

[0025] In one or more embodiments, the electric work machine may be equipped with an insulating plate that covers the magnetic sensor.

[0026] In the above configuration, the heat from the rotor is blocked by the heat-insulating plate, preventing it from being transferred to the magnetic sensor. Furthermore, the magnetic sensor is protected by the heat-insulating plate. Therefore, the magnetic sensor can function properly.

[0027] In one or more embodiments, the electric work machine may include a heat insulating member positioned between the magnetic sensor and the rotor in an axial direction parallel to the rotor's axis of rotation.

[0028] In the above configuration, the heat from the rotor is blocked by the insulating material, preventing it from being transferred to the sensor substrate. As a result, the magnetic sensor can operate properly.

[0029] In one or more embodiments, the heat insulating member may be fixed to the end face of the rotor facing the magnetic sensor.

[0030] In the above configuration, the heat insulating material can rotate together with the rotor. Furthermore, the size of the motor assembly is kept from increasing.

[0031] In one or more embodiments, the electric work machine may include a stirring fan located inside a motor case and rotated by a rotor shaft.

[0032] In the above configuration, the agitator fan agitates the air inside the motor case, making it easier for heat from the air inside the motor case to be transferred to the motor case. The heat transferred to the motor case is then dissipated to the surrounding area. This suppresses the temperature rise inside the motor case. Because the temperature rise inside the motor case is suppressed, the magnetic sensor can operate properly.

[0033] In one or more embodiments, the stirring fan may be fixed to the rotor shaft inside the motor case.

[0034] In the above configuration, the stirring fan can rotate together with the rotor shaft inside the motor case.

[0035] In one or more embodiments, the electric work machine may include a cooling fan located outside the motor case and rotated by the rotor shaft.

[0036] In the above configuration, the motor case is cooled by the rotation of the cooling fan by the rotor shaft. Therefore, the temperature rise of the sensor board is suppressed. Consequently, the magnetic sensor can operate properly. In addition, because the motor case is cooled, the temperature rise of the motor is suppressed, so the motor can operate properly. Furthermore, malfunctions of electronic equipment housed in the motor case due to heat and deterioration of components housed in the motor case due to heat are suppressed. Consequently, the electric work machine is driven properly.

[0037] In one or more embodiments, the cooling fan may be fixed to the end of the rotor shaft located outside the motor case.

[0038] In the above configuration, the cooling fan can rotate together with the rotor shaft outside the motor case.

[0039] In one or more embodiments, the cooling fan may face at least a portion of the outer surface of the motor case.

[0040] In the above configuration, the cooling fan can efficiently direct air to the outer surface of the motor case.

[0041] In one or more embodiments, the electric work machine may include internal heat dissipation fins located on the inner surface of the motor case.

[0042] In the above configuration, the motor case is efficiently cooled by the internal heat dissipation fins.

[0043] The embodiments of this disclosure will be described below with reference to the drawings, but this disclosure is not limited to these embodiments. The components of the embodiments described below can be combined as appropriate. In addition, some components may not be used.

[0044] In the embodiments, the positional relationships of each part will be described using the terms "left," "right," "front," "rear," "up," and "down." These terms indicate relative positions or directions with respect to the center of the electric work machine 1.

[0045] The electric work machine 1 has a motor 12. In this embodiment, the direction parallel to the rotation axis AX of the motor 12 is appropriately referred to as the axial direction. The radial direction of the rotation axis AX of the motor 12 is appropriately referred to as the radial direction. The direction around the rotation axis AX of the motor 12 is appropriately referred to as the circumferential direction or rotational direction.

[0046] In the axial direction, positions close to or approaching the center of the motor 12 are appropriately referred to as the axial inner direction, and positions far from or away from the center of the motor 12 are appropriately referred to as the axial outer direction. In the radial direction, positions close to or approaching the rotation axis AX of the motor 12 are appropriately referred to as the radial inner direction, and positions far from or away from the rotation axis AX of the motor 12 are appropriately referred to as the radial outer direction. In the circumferential direction, positions or directions on one side are appropriately referred to as the circumferential one side, and positions or directions on the other side in the circumferential direction are appropriately referred to as the circumferential other side.

[0047] [First Embodiment] The first embodiment will be described.

[0048] <Electric working equipment> Figure 1 is a left-side perspective view showing the electric work machine 1 according to this embodiment. In this embodiment, the electric work machine 1 is a chainsaw, which is a type of outdoor power equipment.

[0049] The electric work implement 1 comprises a housing 2, a front grip section 3, a handguard 4, a battery cover 5, a controller 6, a trigger lock lever 7, a trigger switch 8, a guide bar 9, a saw chain 10, and a motor assembly 11A.

[0050] The housing 2 is made of synthetic resin. The housing 2 has a motor housing section 14, a battery holding section 15, and a rear grip section 16.

[0051] The motor housing section 14 houses the motor assembly 11A. The motor assembly 11A has a motor 12.

[0052] The battery holder 15 holds the battery pack (not shown). The battery holder 15 has a battery mounting section into which the battery pack is attached. The battery holder 15 holds the battery pack via the battery mounting section. The battery holder 15 is connected to the rear end of the motor housing 14. The battery cover 5 is positioned to cover the battery pack held by the battery holder 15.

[0053] The battery pack is detachable from the battery holder 15. The battery pack includes a secondary battery. In this embodiment, the battery pack includes a rechargeable lithium-ion battery. The battery pack functions as a power supply for the electric work machine 1. By being held in the battery holder 15, the battery pack can supply power to the electric work machine 1.

[0054] The rear grip portion 16 is held in the hand of the user of the electric work implement 1. The rear grip portion 16 is connected to the rear end of the battery holder portion 15. A portion of the rear grip portion 16 is connected to the upper part of the rear end of the battery holder portion 15. A portion of the rear grip portion 16 is connected to the lower part of the rear end of the battery holder portion 15.

[0055] An air intake port 2A is provided on the left side of the motor housing 14. An exhaust port 2B is provided on the front side of the motor housing 14. Air from outside the housing 2 can flow into the housing 2 through the air intake port 2A. Air from inside the housing 2 can flow out to the outside of the housing 2 through the exhaust port 2B.

[0056] The front grip portion 3 is held in the hand of the user of the electric work machine 1. The front grip portion 3 is made of synthetic resin. The front grip portion 3 is a pipe-shaped member. The front grip portion 3 is connected to the housing 2. The left end of the front grip portion 3 is connected to the left side of the motor housing portion 14. The right end of the front grip portion 3 is connected to the right side of the battery holder portion 15.

[0057] The handguard 4 protects the user's hand when gripping the front grip 3. The handguard 4 is positioned in front of the front grip 3. The handguard 4 is connected to the top of the motor housing 14.

[0058] The controller 6 outputs control signals to control the electric work implement 1. The controller 6 controls the drive current supplied from the battery pack to the motor 12. The controller 6 is housed in the motor housing 14.

[0059] The trigger lock lever 7 is operated by the user of the electric work implement 1 to enable the trigger switch 8. The trigger lock lever 7 is located on the rear grip portion 16.

[0060] The trigger switch 8 is operated by the user of the electric work implement 1 to drive the motor 12 of the motor assembly 11A. The trigger switch 8 is located on the rear grip portion 16. The user of the electric work implement 1 can operate the trigger switch 8 with their finger after gripping the rear grip portion 16 with their hand and operating the trigger lock lever 7. When the trigger switch 8 is operated, a drive current is supplied to the motor 12, and the motor 12 is driven.

[0061] The guide bar 9 guides the saw chain 10. The guide bar 9 is a long, plate-shaped member in the front-to-back direction. The guide bar 9 extends forward from the housing 2.

[0062] The saw chain 10 is the output unit of the electric work implement 1, which is driven by the motor 12. The saw chain 10 includes multiple interconnected cutters. The saw chain 10 is positioned around the periphery of the guide bar 9. The motor 12 and the saw chain 10 are connected via a power transmission mechanism (not shown) including a sprocket. When the trigger switch 8 is operated and the motor 12 is driven, the saw chain 10 moves around the periphery of the guide bar 9.

[0063] <Motor Assembly> Figure 2 is a left-side perspective view showing the motor assembly 11A according to this embodiment. Figure 3 is a side view showing the motor assembly 11A according to this embodiment. Figure 4 is a longitudinal cross-sectional view showing the motor assembly 11A according to this embodiment. Figure 5 is a transverse cross-sectional view showing the motor assembly 11A according to this embodiment. Figure 6 is an enlarged longitudinal cross-sectional view of a part of the motor assembly 11A according to this embodiment.

[0064] The motor assembly 11A includes a motor 12, a motor case 13, a bearing 18, a heat transfer resin part 19, a cooling fan 20, a rotating member 64, a sensor substrate 22, a sealing member 23, a pressing mechanism 24, a sealing member 25, and a sealing member 26.

[0065] Motor 12 is the power source for the electric work machine 1. Motor 12 is an electric motor that is driven based on the drive current supplied from the battery pack.

[0066] The motor 12 is an inner-rotor type brushless motor. The motor 12 has a stator 27, a rotor 28 that rotates relative to the stator 27, and a rotor shaft 29 fixed to the rotor 28. The stator 27 is positioned to surround at least a portion of the rotor 28. The rotor 28 rotates around a rotation axis AX. The saw chain 10 is driven by the rotor shaft 29.

[0067] In this embodiment, the rotation axis AX of the rotor 28 extends in the left-right direction. The axial direction parallel to the rotation axis AX of the rotor 28 coincides with the left-right direction.

[0068] The stator 27 includes a stator core 30, an insulator 31, a coil 32, and a busbar unit 33.

[0069] The stator core 30 includes a plurality of laminated steel plates. The steel plates are metal plates mainly composed of iron. The stator core 30 has an annular yoke 34 and teeth 35 that project radially inward from the inner surface of the yoke 34. The yoke 34 is arranged to surround the rotation axis AX. Multiple teeth 35 are arranged in the circumferential direction. In this embodiment, 12 teeth 35 are arranged. The multiple teeth 35 are arranged at equal intervals in the circumferential direction.

[0070] The insulator 31 covers at least a portion of the surface of the stator core 30. The insulator 31 covers at least the outer circumferential surface of the teeth 35. The insulator 31 is made of synthetic resin. The insulator 31 is fixed to the stator core 30. The insulator 31 is integrally molded with the stator core 30. The insulator 31 is fixed to the stator core 30 by insert molding.

[0071] The coil 32 is wound around the teeth 35 via an insulator 31. The coil 32 and the stator core 30 are insulated by the insulator 31. Multiple coils 32 are provided in the circumferential direction. In this embodiment, 12 coils 32 are provided.

[0072] The busbar unit 33 is fixed to the insulator 31 by screws 53. The drive current from the battery pack is supplied to the busbar unit 33 via the controller 6.

[0073] The busbar unit 33 includes an external terminal 42, a short-circuiting member 44, and an insulating member 45.

[0074] External terminal 42 is connected to short-circuit member 44 and connection terminal 47, respectively. External terminal 42 is connected to coil 32 via short-circuit member 44. Short-circuit member 44 connects (short-circuits) a pair of radially opposing coils 32. External terminal 42 is connected to battery pack via connection terminal 47, power line 46, and controller 6. External terminal 42 and connection terminal 47 are fixed together by screws 52. Connection terminal 47 is connected to power line 46. Power line 46 is a lead wire connected to coil 32 via connection terminal 47, external terminal 42, and short-circuit member 44. Drive current from battery pack is supplied to coil 32 via controller 6, power line 46, connection terminal 47, external terminal 42, and short-circuit member 44.

[0075] The insulating member 45 is made of synthetic resin. The insulating member 45 is provided so as to surround the rotating shaft AX. The short-circuiting member 44 is located inside the insulating member 45. The insulating member 45 supports the external terminal 42 and the short-circuiting member 44.

[0076] The controller 6 controls the drive current supplied from the battery pack to the busbar unit 33. The drive current from the battery pack is supplied to the external terminal 42 of the busbar unit 33 via the controller 6, power line 46, and connection terminal 47. The drive current supplied from the battery pack to the external terminal 42 flows through the short-circuit member 44 and is then supplied to the coil 32.

[0077] The rotor 28 has a rotor core 54 and a rotor magnet 55.

[0078] The rotor core 54 includes multiple laminated steel plates. The steel plates are metal plates mainly composed of iron. The rotor core 54 is arranged to surround the rotating shaft AX. The stator core 30 is arranged around the rotor core 54.

[0079] The rotor magnets 55 are permanent magnets. The rotor magnets 55 are supported by the rotor core 54. The rotor magnets 55 are arranged inside the rotor core 54. Multiple rotor magnets 55 are provided in the circumferential direction. In this embodiment, eight rotor magnets 55 are provided.

[0080] The rotor core 54 has a plurality of magnet holes 56 that are spaced apart in the circumferential direction. The magnet holes 56 are formed to penetrate the left end face and the right end face of the rotor core 54. The rotor magnets 55 are placed in the magnet holes 56.

[0081] In this embodiment, the rotor core 54 has a plurality of hollow holes 57 spaced apart in the circumferential direction. The hollow holes 57 are formed to penetrate the left end face and the right end face of the rotor core 54. The hollow holes 57 are located radially inward from the magnet holes 56. In this embodiment, four hollow holes 57 are provided. The hollow holes 57 reduce the weight of the rotor core 54.

[0082] The rotor shaft 29 extends in the axial direction. The central axis of the rotor shaft 29 coincides with the axis of rotation AX. The rotor shaft 29 is positioned inside the rotor core 54. The rotor core 54 and the rotor shaft 29 are fixed together. In this embodiment, a cylindrical member 58 is positioned around the rotor shaft 29. The cylindrical member 58 is made of an electrically insulating material. The rotor shaft 29 is fixed to the rotor core 54 via the cylindrical member 58. The left portion of the rotor shaft 29 protrudes to the left from the left end face of the rotor core 54. The right portion of the rotor shaft 29 protrudes to the right from the right end face of the rotor core 54.

[0083] When drive current is supplied from the battery pack to the coil 32 via the controller 6, a rotating magnetic field is generated in the stator 27. As a result of the generation of the rotating magnetic field, the rotor 28 and rotor shaft 29 rotate around the rotation axis AX.

[0084] The motor case 13 houses at least a portion of the motor 12. In this embodiment, the motor case 13 houses at least the stator 27 and the rotor 28. The motor case 13 has an internal space in which the stator 27 and the rotor 28 are arranged. Within the internal space of the motor case 13, the stator 27 is arranged to surround at least a portion of the rotor 28. The internal space is a closed space. In this embodiment, the internal space is a substantially sealed space. A portion of the rotor shaft 29 is arranged within the internal space.

[0085] The motor case 13 is made of metal. In this embodiment, the motor case 13 is made of aluminum. The motor case 13 may also be made of die-cast aluminum (ADC12).

[0086] The motor case 13 includes a main body 60, a heat dissipation fin 61, and a cover 62.

[0087] The main body 60 houses the stator 27 and rotor 28. The stator 27 and rotor 28 are positioned inside the main body 60.

[0088] The main body 60 includes a cylindrical portion 60A, a protruding portion 60B, and a wall portion 60C. The cylindrical portion 60A is provided to surround the rotation axis AX. The protruding portion 60B is provided to project forward from the cylindrical portion 60A. The wall portion 60C is connected to the right end of the cylindrical portion 60A. Openings 63 are provided at the left ends of the main body 60 and the protruding portion 60B. The stator 27 is inserted into the inside of the main body 60 through the openings 63.

[0089] The heat dissipation fins 61 are provided on the outer surface of the cylindrical portion 60A. The heat dissipation fins 61 are provided so as to protrude radially outward from the outer surface of the cylindrical portion 60A. The heat dissipation fins 61 are arranged so as to extend axially on the outer surface of the cylindrical portion 60A. Multiple heat dissipation fins 61 are provided at intervals in the circumferential direction.

[0090] The cover portion 62 is fixed to the main body portion 60 so as to close the opening 63 of the main body portion 60. By connecting the main body portion 60 and the cover portion 62 so that the opening 63 is closed by the cover portion 62, an internal space is formed between the main body portion 60 and the cover portion 62. After at least a portion of the motor 12, including the stator 27, is placed inside the main body portion 60, the opening 63 of the main body portion 60 is closed by the cover portion 62, so that at least a portion of the motor 12 is placed in the internal space.

[0091] Multiple screw bosses 69 are provided around the opening 63 in the main body 60. In this embodiment, four screw bosses 69 are provided at intervals in the circumferential direction. A screw hole is provided in each of the multiple screw bosses 69. Multiple screw bosses 70 are provided on the periphery of the lid 62. In this embodiment, four screw bosses 70 are provided at intervals in the circumferential direction. An opening is provided in each of the multiple screw bosses 70. With the middle portion of a screw 71 positioned in the opening of the screw boss 70, the tip of the screw 71 is connected to the screw hole of the screw boss 69, thereby fixing the main body 60 and the lid 62 together.

[0092] The lid portion 62 includes a disc portion 62A and a protruding portion 62B. The disc portion 62A is connected to the cylindrical portion 60A. The protruding portion 62B is connected to the protruding portion 60B. The protruding portion 62B is provided to protrude forward from the disc portion 62A.

[0093] The bearing 18 supports the rotor shaft 29. The rotor shaft 29 is rotatably supported by the bearing 18. The bearing 18 is supported by the motor case 13.

[0094] The motor case 13 has a shaft hole 72 in which at least a portion of the rotor shaft 29 is positioned. The shaft hole 72 is provided to connect the internal space of the motor case 13 with the external space of the motor case 13. The shaft hole 72 includes a shaft hole 72L in which the left portion of the rotor shaft 29 is positioned, and a shaft hole 72R in which the right portion of the rotor shaft 29 is positioned. The shaft hole 72L is provided in the disc portion 62A of the lid portion 62. The shaft hole 72R is provided in the wall portion 60C of the main body portion 60.

[0095] The motor case 13 has a peripheral wall portion 101 that defines the shaft hole 72. The peripheral wall portion 101 is substantially cylindrical. The peripheral wall portion 101 includes a peripheral wall portion 101L that defines the shaft hole 72L and a peripheral wall portion 101R that defines the shaft hole 72R. The peripheral wall portion 101L is provided on the disc portion 62A of the lid portion 62. The peripheral wall portion 101L protrudes to the left from the left surface of the disc portion 62A. The peripheral wall portion 101R is provided on the wall portion 60C of the main body portion 60. The peripheral wall portion 101R protrudes to the right from the right surface of the wall portion 60C.

[0096] The bearing 18 includes a left bearing 18L that supports the left portion of the rotor shaft 29 and a right bearing 18R that supports the right portion of the rotor shaft 29. The left bearing 18L is located in the shaft hole 72L. The right bearing 18R is located in the shaft hole 72R.

[0097] The left and right ends of the rotor shaft 29 are located outside the motor case 13. The right end of the rotor shaft 29 is connected to the saw chain 10 via a power transmission mechanism (not shown) including a sprocket. The saw chain 10 is driven by the rotor shaft 29. The rotation of the rotor shaft 29 drives the saw chain 10.

[0098] The heat transfer resin part 19 is housed in the motor case 13. The heat transfer resin part 19 is in contact with the coil 32 and the motor case 13, respectively. The heat transfer resin part 19 is positioned to cover the coil 32. In this embodiment, the heat transfer resin part 19 is in contact with the stator core 30 and the insulator 31, respectively.

[0099] The heat transfer resin part 19 is made of synthetic resin. The heat transfer resin part 19 has high thermal conductivity and electrical insulation properties. For example, if the insulator 31 is made of nylon resin and the thermal conductivity of nylon resin is 0.2 [W / m·K], the thermal conductivity of the synthetic resin used in the heat transfer resin part 19 is higher than 0.2 [W / m·K].

[0100] An example of an insulating synthetic resin with a thermal conductivity higher than 0.2 [W / m·K] is unsaturated polyester resin. The heat transfer resin part 19 may also be made of nylon resin containing an insulating thermal conductive filler.

[0101] After the stator 27 is inserted into the main body 60 through the opening 63, heated and melted synthetic resin is supplied to the inside of the main body 60 through the opening 63. The heat transfer resin part 19 is formed when the synthetic resin supplied to the inside of the main body 60 solidifies.

[0102] The cooling fan 20 is located outside the motor case 13. The cooling fan 20 faces at least a portion of the outer surface of the motor case 13. The cooling fan 20 is fixed to the rotor shaft 29. The cooling fan 20 is rotated by the rotor shaft 29.

[0103] In this embodiment, the cooling fan 20 is positioned to the left of the motor case 13. The cooling fan 20 is fixed to the left end of the rotor shaft 29, which is located outside the motor case 13. The cooling fan 20 faces at least a portion of the outer surface of the motor case 13. In this embodiment, the cooling fan 20 is positioned to face at least a portion of the cover portion 62.

[0104] In this embodiment, the cooling fan 20 is a centrifugal fan. The cooling fan 20 has an intake port 20A provided at the left end of the cooling fan 20 and an outlet port 20F provided at the periphery of the cooling fan 20. The cooling fan 20 generates an airflow that cools the motor case 13. When the rotor shaft 29 rotates, the cooling fan 20 rotates together with the rotor shaft 29. As the cooling fan 20 rotates, the air around the cooling fan 20 is drawn into the intake port 20A. The air drawn into the intake port 20A is blown out from the outlet port 20F. At least a portion of the air blown out from the outlet port 20F hits the outer surface of the motor case 13. This cools the motor case 13.

[0105] In this embodiment, the cooling fan 20 is fixed to the rotor shaft 29 via a fan bush 73. The fan bush 73 is an intermediate member connecting the rotor shaft 29 and the cooling fan 20. The fan bush 73 is positioned outside the motor case 13 to connect the left end of the rotor shaft 29 and the cooling fan 20. When the cooling fan 20 rotates, the fan bush 73 rotates together with the cooling fan 20.

[0106] The rotating member 64 supports the sensor magnet 21. The rotating member 64 is located inside the motor case 13. Inside the motor case 13, the rotating member 64 is fixed to the rotor shaft 29.

[0107] In this embodiment, a sleeve 113 is positioned around the rotor shaft 29. The sleeve 113 is fixed to the rotor shaft 29. The sleeve 113 is made of a metal such as brass. The sleeve 113 functions as a rotational balancer to correct the rotational imbalance of the rotor 28.

[0108] The rotating member 64 is positioned around the sleeve 113. The rotating member 64 is fixed to the sleeve 113. The rotating member 64 is fixed to the rotor shaft 29 via the sleeve 113. As the rotor shaft 29 rotates, the rotating member 64 rotates together with the rotor shaft 29.

[0109] The sensor magnets 21 are fixed to the rotating member 64. The sensor magnets 21 are permanent magnets. Multiple sensor magnets 21 are provided at intervals in the circumferential direction. In this embodiment, eight sensor magnets 21 are provided. In the circumferential direction, the positions of the sensor magnets 21 and the rotor magnets 55 coincide.

[0110] The sensor magnet 21 is positioned inside the rotating member 64. In this embodiment, the rotating member 64 has a plurality of magnet holes 65 spaced apart in the circumferential direction. The magnet holes 65 are formed to penetrate the left end face and the right end face of the rotating member 64. The sensor magnet 21 is positioned in the magnet holes 65.

[0111] The sensor magnet 21 is rotated by the rotor 28. The rotation of the rotating member 64 by the rotor 28 and rotor shaft 29 causes the sensor magnet 21 to rotate.

[0112] The sensor substrate 22 supports the magnetic sensor 74. The sensor substrate 22 is located inside the motor case 13. The sensor substrate 22 is annular in shape. The sensor substrate 22 is positioned around the rotor shaft 29. The sensor substrate 22 includes a printed wiring board (PWB). Epoxy resin is an example of a material used to form the sensor substrate 22. However, the sensor substrate 22 may also be made of a metal such as aluminum, or a heat-dissipating resin with a higher thermal conductivity than epoxy resin.

[0113] In the axial direction, the sensor substrate 22 is positioned between at least a portion of the motor case 13 and the sensor magnet 21. The sensor substrate 22 is fixed to the motor case 13. The sensor substrate 22 is fixed to the cover portion 62 by screws 78.

[0114] The magnetic sensor 74 detects the sensor magnet 21. A Hall element is exemplified as the magnetic sensor 74. The magnetic sensor 74 detects the rotation of the rotor 28 by detecting the sensor magnet 21. Signal lines 75 are connected to the sensor substrate 22. Five signal lines 75 are arranged. The detection signal from the magnetic sensor 74 is transmitted to the controller 6 via the signal lines 75. In this embodiment, the five signal lines 75 are integrated by a tube 115.

[0115] In the axial direction, the rotating member 64 is positioned between the sensor substrate 22 and the rotor 28. The magnetic sensor 74 is supported on the sensor substrate 22 so as to face the sensor magnet 21.

[0116] In this embodiment, at least a portion of the surface of the magnetic sensor 74 and the sensor substrate 22 is covered with a resin film 76. The resin film 76 functions as a heat insulating film.

[0117] The motor case 13 has a wiring passage 79 that connects the internal space of the motor case 13 to the external space of the motor case 13. The wiring passage 79 is provided in the protruding portion 60B of the main body 60. The wiring passage 79 has an insertion end opening 80 that faces the external space of the motor case 13. The insertion end opening 80 is located at the front end of the wiring passage 79.

[0118] Power lines 46 are placed in the wiring passage 79. Power lines 46 are connected to coil 32 via connection terminals 47 and busbar unit 33.

[0119] The sealing member 23 seals the boundary between the power line 46 and the motor case 13. The sealing member 23 seals the boundary between the tube 115 and the motor case 13. The sealing member 23 is substantially cylindrical. The sealing member 23 is made of rubber. The sealing member 23 is placed in the wiring passage 79. The sealing member 23 is inserted into the wiring passage 79 from the insertion end opening 80.

[0120] The sealing member 23 has holes 81 in which the power lines 46 and the tube 115 are respectively placed. There are four holes 81. The four holes 81 are arranged parallel to each other. There are three power lines 46. A power line 46 is placed in each of the three holes 81. There is one tube 115. The tube 115 is placed in one of the holes 81. The outer surface of the power line 46 and the inner surface of the hole 81 are in close contact. The outer surface of the tube 115 and the inner surface of the hole 81 are in close contact.

[0121] The press mechanism 24 applies pressure to the sealing member 23 positioned in the wiring passage 79. The press mechanism 24 tightens the sealing member 23 so that the outer surface of the power line 46 and the inner surface of the hole 81 in the sealing member 23 are in close contact. The press mechanism 24 tightens the sealing member 23 so that the outer surface of the tube 115 and the inner surface of the hole 81 are in close contact. The press mechanism 24 presses the sealing member 23 against the motor case 13 so that the sealing member 23 and at least a portion of the motor case 13 are in close contact.

[0122] The press mechanism 24 includes a press member 91 and a cover member 92. The press member 91 has a ring portion 93 arranged around the seal member 23 and a plurality of claw portions 94 connected to the ring portion 93.

[0123] The ring portion 93 is arranged around the sealing member 23. The claw portion 94 is connected to the front of the ring portion 93. Multiple claw portions 94 are arranged around the sealing member 23. Multiple claw portions 94 can be elastically deformed so that they move closer to each other. That is, the press member 91 can be elastically deformed so that its diameter is reduced at the claw portion 94.

[0124] The cover member 92 is fixed to the motor case 13 while in contact with the press member 91. The cover member 92 has a peripheral wall portion 95 arranged around the claw portion 94 and a fixing portion 96 that is fixed to the motor case 13.

[0125] When the cover member 92 is fixed to the motor case 13 by the screw 99 with the inner surface of the peripheral wall 95 and the claw portion 94 in contact, the cover member 92 moves backward to approach the motor case 13. As the cover member 92 moves backward, the multiple claw portions 94 elastically deform so that they move closer to each other by the peripheral wall 95. As a result, the sealing member 23 is tightened by the multiple claw portions 94. As the sealing member 23 is tightened by the multiple claw portions 94, the outer surface of the power line 46 and the inner surface of the hole 81 come into close contact, and the outer surface of the tube 115 and the inner surface of the hole 81 come into close contact.

[0126] Furthermore, as the cover member 92 moves backward, the press member 91 moves backward together with the cover member 92. As the press member 91 moves backward, the seal member 23 moves backward together with the press member 91 and is pressed against at least a portion of the motor case 13. As the seal member 23 is pressed against at least a portion of the motor case 13, the seal member 23 and the motor case 13 become tightly sealed together.

[0127] The boundary between the power line 46 and the sealing member 23 is sealed by the close contact between the outer surface of the power line 46 and the inner surface of the hole 81. The boundary between the tube 115 and the sealing member 23 is sealed by the close contact between the outer surface of the tube 115 and the inner surface of the hole 81. The boundary between the sealing member 23 and the motor case 13 is sealed by the close contact between the sealing member 23 and the motor case 13. As a result, the boundary between the power line 46 and the motor case 13 is sealed by the sealing member 23, and the boundary between the tube 115 and the motor case 13 is sealed by the sealing member 23.

[0128] The sealing member 25 seals the boundary between the rotor shaft 29 and the motor case 13. The sealing member 25 includes an oil seal. The sealing member 25 is positioned in the shaft hole 72. The sealing member 25 is press-fitted between the rotor shaft 29 and the peripheral wall portion 101. The sealing member 25 is supported by the peripheral wall portion 101. The sealing member 25 includes a sealing member 25L that seals the boundary between the left side of the rotor shaft 29 and the motor case 13, and a sealing member 25R that seals the boundary between the right side of the rotor shaft 29 and the motor case 13. The sealing member 25L is positioned in the shaft hole 72L. The sealing member 25R is positioned in the shaft hole 72R.

[0129] A stopper member 108L is positioned to the left of the sealing member 25L. A stopper member 108R is positioned to the right of the sealing member 25R. The stopper member 108L prevents the sealing member 25L from coming out of the shaft hole 72L. The stopper member 108R prevents the sealing member 25R from coming out of the shaft hole 72R. A circlip is exemplified as the stopper members 108L and 108R.

[0130] The sealing member 26 seals the boundary between the main body 60 and the lid 62. The sealing member 26 includes an O-ring. The main body 60 has a recess 109 that surrounds the opening 63. The sealing member 26 is positioned in the recess 109.

[0131] <Effects> As described above, in this embodiment, the electric work implement 1 comprises a motor 12 and a saw chain 10 which is an output unit. The motor 12 has a stator 27, a rotor 28 that rotates relative to the stator 27, and a rotor shaft 29 fixed to the rotor 28. The saw chain 10 is driven by the rotor shaft 29. The electric work implement 1 comprises a motor case 13 that houses the stator 27 and the rotor 28. The electric work implement 1 comprises a sensor magnet 21 which is a magnet located inside the motor case 13 and rotated by the rotor 28. The electric work implement 1 comprises a sensor substrate 22 located inside the motor case 13 that supports a magnetic sensor 74 which detects the sensor magnet 21.

[0132] In the above configuration, the sensor magnet 21 is rotated by the rotor 28, so the magnetic sensor 74 can detect the rotation of the rotor 28 by detecting the sensor magnet 21. Furthermore, since the sensor magnet 21 and the sensor substrate 22 are each placed inside the motor case 13, they are protected by the motor case 13. The protection of the sensor magnet 21 and the sensor substrate 22 by the motor case 13 suppresses a decrease in the detection accuracy of the magnetic sensor 74. For example, if the sensor magnet 21 is placed outside the motor case 13, magnetic materials such as iron powder present around the motor case 13 may adhere to the sensor magnet 21. Also, if the sensor substrate 22 is placed outside the motor case 13, the magnetic sensor 74 may deteriorate. If magnetic materials adhere to the sensor magnet 21 or the magnetic sensor 74 deteriorates, the detection accuracy of the magnetic sensor 74 may decrease. The protection of the sensor magnet 21 and the sensor substrate 22 by the motor case 13 suppresses a decrease in the detection accuracy of the magnetic sensor 74. The controller 6 can control the motor 12 based on the detection signal from the magnetic sensor 74, which has suppressed a decrease in detection accuracy. This ensures that the electric work machine 1 is driven properly.

[0133] In this embodiment, the sensor substrate 22 is positioned between at least a portion of the motor case 13 and the sensor magnet 21 in an axial direction parallel to the rotation axis AX of the rotor 28.

[0134] In the above configuration, the size of the motor assembly 11A, which includes the motor case 13, sensor magnet 21, and sensor substrate 22, is suppressed.

[0135] In this embodiment, the sensor substrate 22 is fixed to the motor case 13.

[0136] In the above configuration, changes in the relative position between the motor case 13 and the sensor board 22 are suppressed.

[0137] In this embodiment, the motor case 13 includes a main body 60 having an opening 63 and housing the stator 27 and rotor 28, and a lid 62 fixed to the main body 60 so as to close the opening 63. The sensor substrate 22 is fixed to the lid 62.

[0138] In the above configuration, the sensor board 22 is fixed to the lid 62, and the lid 62 is fixed to the main body 60, so that the sensor board 22 is positioned inside the motor case 13.

[0139] In this embodiment, the electric work machine 1 includes a rotating member 64 fixed to the rotor shaft 29 inside the motor case 13. The sensor magnet 21 detected by the magnetic sensor 74 is fixed to the rotating member 64.

[0140] In the above configuration, the sensor magnet 21 fixed to the rotating member 64 is detected by the magnetic sensor 74, thus suppressing the effect of heat from the rotor 28 on the magnetic sensor 74. The rotor 28 may become hot when the motor 12 is driven, potentially generating heat. If the rotor magnet 55 is detected by the magnetic sensor 74, it may be necessary to place the sensor substrate 22 close to the rotor 28. If the sensor substrate 22 is placed close to the rotor 28, the heat from the rotor 28 may prevent the magnetic sensor 74 from functioning properly. The rotating member 64 is unlikely to become hot. Therefore, if the sensor magnet 21 is detected by the magnetic sensor 74, the magnetic sensor 74 can function properly even if the sensor substrate 22 is placed close to the rotating member 64. Furthermore, since both the rotating member 64 and the rotor 28 are located inside the motor case 13, the sensor magnet 21 and the rotor magnet 55 can be magnetized simultaneously during their production. In other words, with both the rotating member 64 and the rotor 28 fixed to the rotor shaft 29, the rotating member 64 and the rotor 28 can be simultaneously fed into the magnetization device. Therefore, misalignment between the sensor magnet 21 and the rotor magnet 55 in the rotational direction is suppressed. As a result, the controller 6 can properly control the motor 12 based on the detection signal from the magnetic sensor 74 that detects the sensor magnet 21.

[0141] In this embodiment, the rotating member 64 is positioned between the sensor substrate 22 and the rotor 28 in an axial direction parallel to the rotation axis AX of the rotor 28.

[0142] In the above configuration, the distance between the sensor substrate 22 and the rotor 28 is increased. Therefore, the effect of heat from the rotor 28 on the magnetic sensor 74 is suppressed. In addition, since the rotating member 64 is placed between the sensor substrate 22 and the rotor 28, the radiant heat from the rotor 28 is blocked by the rotating member 64 and its transmission to the sensor substrate 22 is suppressed. As a result, the magnetic sensor 74 can operate properly.

[0143] In this embodiment, the sensor substrate 22 may be made of metal or heat-dissipating resin.

[0144] In the above configuration, since the sensor substrate 22 is made of a material that easily dissipates heat, even if heat from the rotor 28 is transferred to the sensor substrate 22, the temperature rise of the sensor substrate 22 is suppressed. Furthermore, because the sensor substrate 22 is connected to the motor case 13, the heat from the sensor substrate 22 is transferred to the motor case 13 and dissipated around the motor case 13. As a result, the magnetic sensor 74 can operate properly.

[0145] In this embodiment, the electric work machine 1 includes a cooling fan 20 located outside the motor case 13 and rotated by the rotor shaft 29.

[0146] In the above configuration, the motor case 13 is cooled by the rotation of the cooling fan 20 by the rotor shaft 29. As a result, the temperature rise of the sensor board 22 is suppressed. Therefore, the magnetic sensor 74 can operate properly. In addition, since the motor case 13 is cooled, the temperature rise of the motor 12 is suppressed, so the motor 12 can operate properly. Furthermore, malfunctions of electronic equipment housed in the motor case 13 due to heat and deterioration of components housed in the motor case 13 due to heat are suppressed. Therefore, the electric work machine 1 is driven properly.

[0147] In this embodiment, the cooling fan 20 is fixed to the end of the rotor shaft 29, which is located outside the motor case 13.

[0148] In the above configuration, the cooling fan 20 can rotate together with the rotor shaft 29 outside the motor case 13.

[0149] In this embodiment, the cooling fan 20 faces at least a portion of the outer surface of the motor case 13.

[0150] In the above configuration, the cooling fan 20 can efficiently direct air onto the outer surface of the motor case 13.

[0151] [Second Embodiment] A second embodiment will now be described. In the following description, components that are the same as or equivalent to those in the above-described embodiment will be denoted by the same reference numerals, and the descriptions of those components will be simplified or omitted.

[0152] Figure 7 is an enlarged longitudinal cross-sectional view of a part of the motor assembly 11B according to this embodiment. As shown in Figure 7, the motor assembly 11B has a sensor substrate 22 located inside the motor case 13. The sensor substrate 22 supports a magnetic sensor 74. Similar to the first embodiment described above, the sensor substrate 22 may be made of epoxy resin, metal, or a heat-dissipating resin with a higher thermal conductivity than epoxy resin.

[0153] In this embodiment, the motor assembly 11B does not have a rotating member (64) and a sensor magnet (21). The magnetic sensor 74 detects the rotor magnet 55 which is rotated by the rotor 28. The rotor 28, which includes the rotor magnet 55, is located inside the motor case 13.

[0154] In this embodiment, the motor assembly 11B has a heat insulating plate 760 that covers at least a portion of the surface of the magnetic sensor 74 and the sensor substrate 22. The heat insulating plate 760 is made of synthetic resin.

[0155] Figure 8 is an exploded perspective view showing the sensor substrate 22 and the heat insulating plate 760 according to this embodiment. The heat insulating plate 760 includes a first heat insulating plate 760A that covers the left side of the sensor substrate 22 and a second heat insulating plate 760B that covers the right side of the sensor substrate 22. The magnetic sensor 74 is located on the right side of the sensor substrate 22. In addition to the magnetic sensor 74, a plurality of electronic components 77 are also located on the right side of the sensor substrate 22. Examples of electronic components 77 located on the sensor substrate 22 include capacitors, resistors, diodes, and thermistors. The second heat insulating plate 760B is located so as to cover the magnetic sensor 74 and the electronic components 77, respectively.

[0156] As described above, in this embodiment, the motor assembly 11B has a heat insulating plate 760 that covers at least a portion of the surface of the magnetic sensor 74 and the sensor substrate 22.

[0157] In the above configuration, the heat from the rotor 28 is shielded by the heat-insulating plate 760, preventing it from being transferred to the magnetic sensor 74 and the sensor substrate 22. Furthermore, the magnetic sensor 74 and the sensor substrate 22 are protected by the heat-insulating plate 760. Therefore, the magnetic sensor 74 can operate properly.

[0158] [Third Embodiment] A third embodiment will now be described. In the following description, components that are the same as or equivalent to those in the embodiments described above will be denoted by the same reference numerals, and the descriptions of those components will be simplified or omitted.

[0159] Figure 9 is an enlarged longitudinal cross-sectional view of a part of the motor assembly 11C according to this embodiment. As shown in Figure 9, the motor assembly 11C has a sensor substrate 22 located inside the motor case 13. The sensor substrate 22 supports a magnetic sensor 74. Similar to the first embodiment described above, the sensor substrate 22 may be made of epoxy resin, metal, or a heat-dissipating resin with a higher thermal conductivity than epoxy resin.

[0160] The motor assembly 11C has a heat insulating member 770 positioned axially between the sensor substrate 22 and the rotor 28. The heat insulating member 770 is a plate-shaped member made of synthetic resin. The heat insulating member 770 is fixed to the left end face of the rotor 28 facing the sensor substrate 22.

[0161] As described above, in this embodiment, the motor assembly 11C has a heat insulating member 770 that is positioned between the sensor substrate 22 and the rotor 28 in an axial direction parallel to the rotation axis AX of the rotor 28.

[0162] In the above configuration, the heat from the rotor 28 is blocked by the heat insulating member 770, and its transfer to the sensor substrate 22 is suppressed. As a result, the magnetic sensor 74 can operate properly.

[0163] In this embodiment, the heat insulating member 770 is fixed to the left end face of the rotor 28 facing the sensor substrate 22.

[0164] In the above configuration, the heat insulating member 770 can rotate together with the rotor 28. Furthermore, the size of the motor assembly 11C is kept from increasing.

[0165] [Fourth Embodiment] A fourth embodiment will now be described. In the following description, components that are the same as or equivalent to those in the embodiments described above will be denoted by the same reference numerals, and the descriptions of those components will be simplified or omitted.

[0166] Figure 10 is a longitudinal cross-sectional view showing the motor assembly 11D according to this embodiment. Figure 11 is an enlarged longitudinal cross-sectional view of a part of the motor assembly 11D according to this embodiment. As shown in Figures 10 and 11, the motor assembly 11D has a sensor substrate 22 located inside the motor case 13. The sensor substrate 22 supports a magnetic sensor 74. Similar to the first embodiment described above, the sensor substrate 22 may be made of epoxy resin, metal, or a heat-dissipating resin with a higher thermal conductivity than epoxy resin.

[0167] The motor assembly 11D has a stirring fan 220 located inside the motor case 13 and rotated by the rotor shaft 29. The stirring fan 220 is fixed to the rotor shaft 29 inside the motor case 12. In this embodiment, the stirring fan 220 includes a stirring fan 220L fixed to the left side of the rotor shaft 29 and a stirring fan 220R fixed to the right side of the rotor shaft 29. As the rotor shaft 29 rotates, the stirring fan 220 can rotate together with the rotor shaft 29 inside the motor case 13. As the stirring fan 220 rotates, the air inside the motor case 13 is stirred.

[0168] As described above, in this embodiment, the motor assembly 11D has a stirring fan 220 located inside the motor case 13 and rotated by the rotor shaft 29.

[0169] In the above configuration, the agitation fan 220 agitates the air inside the motor case 13, making it easier for heat from the air inside the motor case 13 to be transferred to the motor case 13. The heat transferred to the motor case 13 is dissipated to the surrounding area. This suppresses the temperature rise inside the motor case 13. Because the temperature rise inside the motor case 13 is suppressed, the magnetic sensor 74 can operate properly.

[0170] In this embodiment, the stirring fan 220 is fixed to the rotor shaft 29 inside the motor case 13.

[0171] In the above configuration, the stirring fan 220 can rotate together with the rotor shaft 29 inside the motor case 13.

[0172] [Fifth Embodiment] A fifth embodiment will now be described. In the following description, components that are the same as or equivalent to those in the embodiments described above will be denoted by the same reference numerals, and the descriptions of those components will be simplified or omitted.

[0173] Figure 12 is a longitudinal cross-sectional view showing the motor assembly 11E according to this embodiment. Figure 13 is a left-side perspective view showing the cover portion 620 according to this embodiment. Figure 14 is a right-side perspective view showing the cover portion 620 according to this embodiment.

[0174] As shown in Figure 12, the motor assembly 11E has a sensor substrate 22 located inside the motor case 13. The sensor substrate 22 supports a magnetic sensor 74. Similar to the first embodiment described above, the sensor substrate 22 may be made of epoxy resin, metal, or a heat-dissipating resin with a higher thermal conductivity than epoxy resin.

[0175] As shown in Figure 14, the motor assembly 11E has internal heat dissipation fins 612 arranged on the inner surface of the motor case 13. The inner surface of the motor case 13 faces the internal space of the motor case 13. In this embodiment, the internal heat dissipation fins 612 are arranged on the inner surface of the lid portion 620. The internal heat dissipation fins 612 are provided so as to protrude to the right from the inner surface (right surface) of the lid portion 620. The internal heat dissipation fins 612 are provided so as to extend radially. Multiple internal heat dissipation fins 612 are provided spaced apart in the circumferential direction.

[0176] As shown in Figure 13, the lid 620 has external heat dissipation fins 611. The external heat dissipation fins 611 are arranged on the outer surface of the lid 620. The external heat dissipation fins 611 are provided so as to protrude to the left from the outer surface (left side) of the lid 620. The external heat dissipation fins 611 are provided so as to extend radially. Multiple external heat dissipation fins 611 are provided at intervals in the circumferential direction.

[0177] As described above, in this embodiment, the motor assembly 11E has internal heat dissipation fins 612 located on the inner surface of the motor case 13.

[0178] In the above configuration, the motor case 13 is efficiently cooled by the internal heat dissipation fins 612.

[0179] In this embodiment, the internal heat dissipation fins 612 are arranged on the inner surface of the lid portion 620.

[0180] In the above configuration, the internal heat dissipation fins 612 are positioned on the lid portion 620 facing the cooling fan 20, so the motor case 13 is cooled efficiently.

[0181] In this embodiment, the motor assembly 11E has external heat dissipation fins 611 located on the outer surface of the cover portion 620.

[0182] In the above configuration, the external heat dissipation fins 611 are positioned on the lid portion 620 facing the cooling fan 20, so the motor case 13 is cooled efficiently.

[0183] [Other embodiments] In the above embodiment, the magnetic sensor 74 is provided on the sensor substrate 22. The magnetic sensor 74 does not have to be provided on the sensor substrate 22. The magnetic sensor 74 may be provided directly on the resin member or directly connected to the lead wire (signal wire).

[0184] In the above-described embodiment, the motor 12 is an inner rotor type brushless motor. The motor 12 may also be an outer rotor type brushless motor. In an outer rotor type brushless motor, the teeth protrude radially outward from the annular yoke.

[0185] In the above embodiment, the electric work implement 1 is a chainsaw, which is a type of gardening tool. Gardening tools are not limited to chainsaws. Examples of gardening tools include hedge trimmers, lawnmowers, brush cutters, and blowers. The electric work implement 1 may also be an electric power tool. Examples of electric power tools include driver drills, impact driver drills, angle drills, impact drivers, grinders, hammers, hammer drills, circular saws, and reciprocating saws.

[0186] In the above-described embodiment, a battery pack mounted on the battery mounting section is used as the power source for the electric work machine. Commercial power (AC power) may also be used as the power source for the electric work machine. [Explanation of Symbols]

[0187] 1…Electric work implement, 2…Housing, 2A…Air intake, 2B…Exhaust, 3…Front grip section, 4…Handguard, 5…Battery cover, 6…Controller, 7…Trigger lock lever, 8…Trigger switch, 9…Guide bar, 10…Saw chain (output section), 11A…Motor assembly, 11B…Motor assembly, 11C…Motor assembly, 11D…Motor assembly, 11E…Motor assembly, 12…Motor, 13…Motor case, 14…Motor housing, 15…Battery holder, 16…Rear grip section, 18…Bearing, 18L…Left Bearing, 18R...Right bearing, 19...Heat transfer resin part, 20...Cooling fan, 20A...Intake port, 20F...Outlet port, 21...Sensor magnet, 22...Sensor circuit board, 23...Sealing member, 24...Pressing mechanism, 25...Sealing member, 25L...Sealing member, 25R...Sealing member, 26...Sealing member, 27...Stator, 28...Rotor, 29...Rotor shaft, 30...Stator core, 31...Insulator, 32...Coil, 33...Busbar unit, 34...Yoke, 35...Teeth, 42...External terminal, 44...Short-circuiting member, 45...Insulating member, 46...Power line, 47...Connection terminal 52...screw, 53...screw, 54...rotor core, 55...rotor magnet, 56...magnet hole, 57...hollow hole, 58...cylindrical member, 60...main body, 60A...cylindrical part, 60B...protruding part, 60C...wall part, 61...heat dissipation fin, 62...lid part, 62A...disc part, 62B...protruding part, 63...opening, 64...rotating member, 65...magnet hole, 69...screw boss part, 70...screw boss part, 71...screw, 72...shaft hole, 72L...shaft hole, 72R...shaft hole, 73...fan bush, 74...magnetic sensor, 75...signal line, 76...resin film, 77...electronic component, 78...screw, 79...wiring passage ,80...Insertion end opening, 81...Hole, 91...Pressed member, 92...Cover member, 93...Ring part, 94...Claw part, 95...Peripheral wall part, 96...Fixing part, 99...Screw, 101...Peripheral wall part, 101L...Peripheral wall part, 101R...Peripheral wall part, 108L...Stopper member, 108R...Stopper member, 109...Recess, 113...Sleeve, 115...Tube, 220...Agitation fan, 220L...Agitation fan, 220R...Agitation fan, 611...External heat dissipation fin, 612...Internal heat dissipation fin, 620...Lid part, 760...Insulation plate, 760A...First insulation plate, 760B...Second insulation plate, 770...Insulation member.

Claims

1. A motor comprising: a stator having a stator core and coils wound around the teeth of the stator core via an insulator; a rotor that rotates relative to the stator and includes a rotor core and rotor magnets supported by the rotor core; and a rotor shaft fixed to the rotor; The output unit is driven by the rotor shaft, A motor case housing the stator and rotor, and having wiring passages through which power lines carrying drive current supplied to the coil are arranged, A rotating member is disposed inside the motor case and fixed to the rotor shaft, A sensor magnet fixed to the aforementioned rotating member, A magnetic sensor is disposed inside the motor case to detect the sensor magnet, A cooling fan is provided, which is located outside the motor case, fixed to the end of the rotor shaft located outside the motor case, and facing at least a portion of the outer surface of the motor case. In an axial direction parallel to the rotation axis of the rotor, the rotating member is positioned between the magnetic sensor and the rotor. The rotor magnet is placed in a first magnet hole formed to penetrate one end face and the other end face of the rotor core. The sensor magnet is placed in a second magnet hole formed to penetrate one end face and the other end face of the rotating member. In the circumferential direction, the number of sensor magnets and the number of rotor magnets coincide, and the positions of the sensor magnets and the positions of the rotor magnets coincide. In the radial direction, the position of the sensor magnet and the position of the rotor magnet coincide. The rotor magnet and the sensor magnet are opposite each other. Electric work equipment.

2. The sensor includes a sensor substrate that supports the aforementioned magnetic sensor, The electric work machine according to claim 1.

3. In an axial direction parallel to the rotation axis of the rotor, the sensor substrate is positioned between at least a part of the motor case and the sensor magnet. The electric work machine according to claim 2.

4. The sensor board is fixed to the motor case. The electric work machine according to claim 2 or claim 3.

5. The motor case includes a main body having an opening and housing the stator and the rotor, and a lid fixed to the main body so as to close the opening. The sensor substrate is fixed to the lid portion. The electric work machine according to claim 4.

6. The sensor substrate is made of metal or heat-dissipating resin. An electric work machine according to any one of claims 2 to 5.

7. The magnetic sensor is covered by an insulating plate, An electric work machine according to any one of claims 1 to 6.

8. The rotor is provided with a heat insulating member positioned between the magnetic sensor and the rotor in an axial direction parallel to the rotor's rotation axis. An electric work machine according to any one of claims 1 to 7.

9. The heat insulating member is fixed to the end face of the rotor facing the magnetic sensor. The electric work machine according to claim 8.

10. The motor case is housed inside the motor case and includes a stirring fan that is rotated by the rotor shaft, An electric work machine according to any one of claims 1 to 9.

11. The stirring fan is fixed to the rotor shaft inside the motor case. The electric work machine according to claim 10.

12. The motor case is equipped with internal heat dissipation fins arranged on its inner surface. An electric work machine according to any one of claims 1 to 11.

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