JP7549494B2 - Electric work machine - Google Patents

Description

The technology disclosed in this specification relates to electric work machines.

Patent Document 1 discloses an electric work machine. The electric work machine includes an electric motor having a rotor and a stator surrounding the rotor, and a motor housing having an opening through which the electric motor is housed.

JP 2016-78005 A

In the electric work machine described above, a washer may be fixed to the motor housing using a fastener to prevent the stator of the electric motor from coming off the motor housing. The washer abuts against the stator and the motor housing from a first direction from the opening toward the electric motor, and restricts the stator from moving relative to the motor housing in a direction opposite to the first direction.

A typical washer has a circular shape, and the through hole into which the fastener is inserted is located at the center of the circle. Therefore, when the washer fixed to the motor housing is viewed in the first direction, the distance from the center of the through hole in the radial direction of the rotor to the outer end of the washer is the same as the distance from the center of the through hole in the radial direction of the rotor to the inner end of the washer. Since the motor housing is formed to have dimensions as small as possible in the radial direction of the rotor, if a circular washer is used, it becomes necessary to make the part of the motor housing that abuts against the washer a shape that protrudes outward. This specification discloses a technology that can further simplify the shape of the motor housing.

This specification discloses an electric working machine. The electric working machine includes an electric motor having a rotor and a stator surrounding the rotor, a motor housing having an opening through which the electric motor is accommodated, a washer having a through hole that abuts against the stator and the motor housing from a first direction from the opening toward the electric motor and restricts the stator from moving in the opposite direction to the first direction relative to the motor housing, and a fastener that is inserted into the through hole and fixes the washer to the motor housing. When the washer fixed to the motor housing is viewed in the first direction, the distance from the center of the through hole in the radial direction of the rotor to the outer end of the washer is shorter than the distance from the center of the through hole in the radial direction of the rotor to the inner end of the washer.

In the above configuration, the portion of the motor housing that contacts the washer can be made to protrude outward less than when a circular washer is used. This allows the shape of the motor housing to be simplified.

1 is a perspective view of an electric operating machine 2 of a first embodiment as viewed from the rear right side. FIG. 1 is a perspective view of an electric working machine 2 of a first embodiment as viewed from the front left side. FIG. 1 is a view of the vicinity of a trigger 14 of an electric working machine 2 with a right grip housing 20 removed according to a first embodiment, as viewed from the right side. FIG. FIG. 2 is a perspective view of the electric working machine 2 of the first embodiment with the right grip housing 20 removed, as viewed from the rear right side. 1 is a cross-sectional view of an electric working machine 2 with a grip housing 10 of a first embodiment removed. FIG. 13 is a rear view of the electric motor 106 of the first embodiment, the motor housing 66 with the cover member 100 removed, the washer 130, and the fastener 132. FIG. 2 is a perspective view of a washer 130 according to the first embodiment. FIG. 2 is a perspective view of the electric motor 106 and the motor housing 66 of the first embodiment as viewed from the rear right side. FIG. 11 is a view of the electric operating machine 2 of the second embodiment as seen from the right side.

Representative and non-limiting examples of the present invention are described in detail below with reference to the drawings. This detailed description is intended simply to provide those skilled in the art with details for implementing preferred examples of the present invention, and is not intended to limit the scope of the present invention. Additionally, the additional features and inventions disclosed can be used separately or together with other features and inventions to provide further improved electric operating machines.

In addition, the combinations of features and steps disclosed in the following detailed description are not essential to the implementation of the present invention in the broadest sense, but are described only to specifically illustrate representative examples of the present invention. Furthermore, the various features of the following representative examples, as well as the various features described in the claims, do not have to be combined in the exact order of the examples described herein or in the order listed to provide additional and useful embodiments of the present invention.

All features described in the specification and/or claims are intended to be disclosed individually and independently of one another as limitations to the specific features described in the original disclosure and claims, apart from the configuration of features described in the examples and/or claims. Furthermore, all numerical ranges and group or collective descriptions are intended to disclose intermediate configurations thereof as limitations to the specific features described in the original disclosure and claims.

In one or more embodiments, the washer may include a first portion in which the through hole is located and a second portion located radially inward of the first portion. The width of the second portion in the circumferential direction of the rotor may be greater than the width of the first portion in the circumferential direction of the rotor.

In the above configuration, compared to when the width of the second portion is the same as the width of the first portion, the area of the washer facing the stator can be sufficiently secured, and the stator can be sufficiently prevented from slipping out of the motor housing.

In one or more embodiments, the motor housing may have a first recess having a shape corresponding to a shape of the first portion. The stator may have a second recess having a shape corresponding to a shape of the second portion. When the washer is secured to the motor housing, the first portion may be disposed in the first recess and the second portion may be disposed in the second recess.

In the above configuration, when fixing the washer to the motor housing, it is necessary to adjust the orientation of the washer so that the first portion abuts against the motor housing and the second portion abuts against the stator. By placing the first portion in the first recess and the second portion in the second recess, the orientation of the washer can be easily adjusted.

In one or more embodiments, the electric work machine may further include a fan driven by the electric motor and a blowing nozzle through which air blown by the fan flows. The air blown by the rotation of the fan may flow along the motor housing.

The above electric work machine functions as a blower. Air caused by the rotation of the fan flows along the motor housing, so if the motor housing has a shape that protrudes outward, this causes turbulence in the air flow. With the above configuration, the amount of protrusion at the point of the motor housing that abuts against the washer can be reduced, preventing turbulence in the air flow.

(First embodiment)
An electric working machine 2 according to a first embodiment will be described with reference to Figures 1 to 8. The electric working machine 2 is a blower used to blow away fallen leaves and the like. As shown in Figures 1 and 2, the electric working machine 2 includes a grip housing 10, a power cord 12, a trigger 14, a cruise control lever 16, and a control unit 18 (see Figure 4). In the following description, the longitudinal direction of the electric working machine 2 is referred to as the front-rear direction, the direction perpendicular to the front-rear direction is referred to as the up-down direction of the electric working machine 2, and the direction perpendicular to the front-rear direction and the up-down direction is referred to as the left-right direction of the electric working machine 2.

The grip housing 10 is composed of a right grip housing 20 and a left grip housing 22. The right grip housing 20 defines the outer shape of the right half of the grip housing 10, and the left grip housing 22 defines the outer shape of the left half of the grip housing 10. The grip housing 10 comprises a first housing 26, a second housing 28, a third housing 30, and a fourth housing 32. The first housing 26, the second housing 28, the third housing 30, and the fourth housing 32 are integrally formed. The first housing 26 extends in the longitudinal direction.

The second housing 28 extends from the front of the top surface of the first housing 26 toward the rear and upper side. The third housing 30 extends from the rear of the top surface of the first housing 26 toward the rear and upper side. The fourth housing 32 extends from the upper part of the rear surface of the second housing 28 toward the upper part of the front surface of the third housing 30. The cross-sectional shape of the fourth housing 32 is approximately circular. The fourth housing 32 is held by the operator. The power cord 12 is connected to the rear surface of the third housing 30. Power is supplied to the electric work machine 2 via the power cord 12. The power cord 12 is connected, for example, to a backpack battery carried on the back of the operator or to an external power source.

A main power switch 36 and a main power LED 38 are arranged on the top surface of the third housing 30. The main power switch 36 accepts operation by the operator to switch the electric work machine 2 between the on and off states. The main power LED 38 indicates the on and off states of the electric work machine 2.

The trigger 14 is attached to the front lower part of the fourth housing 32. The operator can operate the trigger 14 with the fingers of the hand holding the fourth housing 32. As shown in FIG. 3, the trigger 14 includes a trigger operating portion 42, a trigger protrusion 44, and a switch pressing portion 46. The trigger operating portion 42, the trigger protrusion 44, and the switch pressing portion 46 are integrally formed. The trigger operating portion 42 is supported by the second housing 28 so as to be rotatable around a rotation axis AX1. When the trigger operating portion 42 is pressed by the operator, the trigger operating portion 42 rotates around the rotation axis AX1. The rotation axis AX1 is disposed at the front end of the trigger operating portion 42. Even when the trigger 14 is completely pressed by the operator, the trigger operating portion 42 protrudes downward from the bottom surface of the fourth housing 32.

The trigger protrusion 44 and the switch pressing portion 46 are disposed inside the second housing 28. The trigger protrusion 44 is disposed at the front end of the trigger operating portion 42. The trigger protrusion 44 extends in a direction substantially perpendicular to the upper surface of the trigger operating portion 42. The switch pressing portion 46 is disposed at the front end of the trigger operating portion 42. The switch pressing portion 46 extends from the trigger operating portion 42 toward the front side. The trigger protrusion 44 and the switch pressing portion 46 rotate together with the trigger operating portion 42 around the rotation axis AX1. When the switch pressing portion 46 rotates, the switch pressing portion 46 presses the first switch 118 downward. Also, when the trigger protrusion 44 rotates beyond a predetermined position, the plate member 124 is pushed toward the rear side, and the second switch 120 is pressed.

As shown in FIG. 2, the cruise control lever 16 is attached to the second housing 28 near the connection point between the second housing 28 and the fourth housing 32. The cruise control lever 16 can rotate around the rotation axis AX2. The cruise control lever 16 includes a lever operating part 50 and a stopper part 56 (see FIG. 3). The lever operating part 50 is disposed outside the second housing 28. The lever operating part 50 is operated by an operator. As shown in FIG. 3, the stopper part 56 is disposed inside the second housing 28. When the lever operating part 50 is operated, the stopper part 56 rotates around the rotation axis AX2. The stopper part 56 can abut against the trigger protrusion 44 from the rear side. When the stopper part 56 abuts against the trigger protrusion 44 and is fixed at the desired position, the trigger protrusion 44 cannot return to the rear side. This maintains the trigger 14 in a pressed-in state.

As shown in FIG. 4, an opening 62 is formed on the front surface of the first housing 26. The opening 62 is located near the connection point between the first housing 26 and the second housing 28. The opening 62 connects the inside and outside of the grip housing 10.

The control unit 18 is disposed inside the first housing 26. The control unit 18 is disposed along the front-rear and left-right directions. The control unit 18 is disposed near the connection point between the first housing 26 and the second housing 28. In the up-down direction, the control unit 18 is disposed above the opening 62. Although not shown in the figure, the control unit 18 is composed of a control board having a microcomputer and multiple switching elements, and a case to which the control board is attached. The switching elements are, for example, IGBTs or MOSFETs. The switching elements are switched between an on state and an off state by being controlled by the microcomputer.

The electric work machine 2 further includes a motor housing 66, a rear housing 68, a jet nozzle 70, and a cover member 72. The motor housing 66 is disposed inside the first housing 26. The rear housing 68 is connected to the rear end of the motor housing 66 and protrudes rearward from the rear end of the first housing 26. The rear housing 68 is also fixed to the first housing 26. The jet nozzle 70 is connected to the front end of the motor housing 66 and protrudes forward from the front end of the first housing 26. The jet nozzle 70 is also fixed to the first housing 26.

As shown in FIG. 5, the rear housing 68 has a cylindrical shape in which the diameter of the inner circumferential surface decreases from the rear side to the front side. The rear housing 68 has an upstream passage 84 inside. A cover member 72 is attached to the rear end of the rear housing 68. The cover member 72 covers the rear end opening of the rear housing 68. The cover member 72 has multiple air intake holes 72a. The multiple air intake holes 72a penetrate the cover member 72 in the front-rear direction. The multiple air intake holes 72a communicate between the outside of the electric work machine 2 and the upstream passage 84 of the rear housing 68.

The ejection nozzle 70 includes a first ejection nozzle 86 and a second ejection nozzle 88 (see FIG. 1). The second ejection nozzle 88 is removably attached to the front of the first ejection nozzle 86. The first ejection nozzle 86 and the second ejection nozzle 88 have a cylindrical shape. The first ejection nozzle 86 and the second ejection nozzle 88 have a downstream passage 90 therein. An opening 86a is formed at the upper end of the first ejection nozzle 86. The opening 86a is located below the control unit 18.

The motor housing 66 includes an outer tubular member 80, a plurality of fins 96, an inner tubular member 98, and a cover member 100. The outer tubular member 80, the plurality of fins 96, and the inner tubular member 98 are integrally formed. The outer tubular member 80 has a cylindrical shape extending in the front-rear direction. The outer tubular member 80 has an air passage 82 therein. The upstream end of the air passage 82 is connected to the upstream passage 84 of the rear housing 68, and the downstream end of the air passage 82 is connected to the downstream passage 90 of the ejection nozzle 70. The plurality of fins 96 extend from the inner peripheral surface of the outer tubular member 80 toward the central axis of the outer tubular member 80. As shown in FIG. 6, the plurality of fins 96 are arranged at equal intervals from each other in the circumferential direction of the inner peripheral surface of the outer tubular member 80.

As shown in FIG. 5, the inner tubular member 98 is disposed inside the outer tubular member 80. The inner tubular member 98 extends in the front-rear direction. A plurality of fins 96 extending from the inner circumferential surface of the outer tubular member 80 are connected to the outer peripheral surface of the inner tubular member 98. A lid member 100 is attached to the rear end of the inner tubular member 98. The lid member 100 closes the rear end opening 102 of the inner tubular member 98. A plurality of holes 161 (see FIG. 8) are formed in the rear end of the lid member 100. The detailed configuration of the lid member 100 will be described later. A cone 104 is attached to the front end of the inner tubular member 98. The diameter of the outer peripheral surface of the cone 104 decreases from the rear side to the front side. A tip opening is formed at the tip of the cone 104.

The electric work machine 2 further includes an electric motor 106 and a fan 108. The electric motor 106 is, for example, an inner rotor type brushless motor. The electric motor 106 rotates by power supplied via the power cord 12. The electric motor 106 includes a rotor 110, a stator 112, and a shaft 114. The rotor 110 and the stator 112 are disposed inside the inner cylindrical member 98. The rotor 110 extends in the front-rear direction. The center of rotation of the rotor 110 is the same as the center of the inner peripheral surface of the outer cylindrical member 80. The stator 112 surrounds the outer peripheral surface of the rotor 110. The shaft 114 extends from the inside of the inner cylindrical member 98 toward the rear, and then extends through the cover member 100 to the outside of the inner cylindrical member 98. The shaft 114 is rotatably supported by the motor housing 66 via bearing 115a, and is rotatably supported by the cover member 100 via bearing 115b. The shaft 114 rotates together with the rotor 110.

The operation of the electric motor 106 is controlled by a microcomputer (not shown) of the control unit 18 executing control to switch a switching element (not shown) between an on state and an off state. When the first switch 118 is pressed, the electric motor 106 is controlled to a rotation speed according to the amount of pressing of the first switch 118. Note that the rotation speed of the electric motor 106 increases as the amount of pressing of the first switch 118 increases. On the other hand, when the second switch 120 is pressed, the electric motor 106 is controlled to a predetermined rotation speed. In this embodiment, the rotation speed of the electric motor 106 when the second switch 120 is pressed is greater than the maximum rotation speed of the electric motor 106 when the first switch 118 is pressed.

The fan 108 is attached to the rear end of the shaft 114. The fan 108 is, for example, an axial fan. The fan 108 rotates by being driven by the electric motor 106. When the fan 108 rotates, negative pressure is generated behind the fan 108. As a result, air flows from the multiple intake holes 72a of the cover member 72 into the upstream passage 84 of the rear housing 68 and flows into the air passage 82 of the outer tubular member 80. The air is then sent to the front side by the fan 108, flows through the air passage 82 and the downstream passage 90 in order, and flows out from the tip opening of the second ejection nozzle 88. In addition, a part of the air sent to the front side by the fan 108 enters the inside of the inner tubular member 98 from the multiple holes 161 formed in the rear end of the cover member 100, flows inside the inner tubular member 98 toward the front side, and then flows from the tip opening of the cone 104 to the downstream passage 90. This cools the electric motor 106. Furthermore, a portion of the air flowing through the downstream passage 90 passes through the opening 86a and flows out of the first ejection nozzle 86. The air flows between the bottom surface of the control unit 18 and the outer circumferential surface of the first ejection nozzle 86, and flows out of the grip housing 10 through the opening 62. This cools the control unit 18.

As shown in FIG. 6, the electric operating machine 2 further includes two washers 130 and two fasteners 132. The washer 130 is fixed to the inner tubular member 98 using the fastener 132. As shown in FIG. 7, the washer 130 includes a first portion 136 and a second portion 138. The washer 130 also has a through hole 140. The fastener 132 is inserted into the through hole 140. The first portion 136 includes a semicircular portion 142 and a rectangular portion 144. The through hole 140 is disposed across the semicircular portion 142 and the rectangular portion 144. The cross section of the semicircular portion 142 has a semicircular shape. The outer peripheral surface 142a of the semicircular portion 142 overlaps with the circumference of a virtual circle centered on the center CP of the through hole 140. As shown in FIG. 6, the outer peripheral surface 142a of the semicircular portion 142 faces radially outward of the rotor 110. The outer end of the washer 130, which is radially outward of the rotor 110 from the center CP of the through hole 140 (see FIG. 7), is located on the outer peripheral surface 142a. As shown in FIG. 7, the cross section of the rectangular portion 144 has a rectangular shape.

The second part 138 is connected to the rectangular part 144. The second part 138 sandwiches the rectangular part 144 between the semicircular part 142 and the second part 138. The second part 138 has an outer peripheral surface 138a and a connection surface 138b that connects the outer peripheral surface 138a and the outer surface of the rectangular part 144. The outer peripheral surface 138a overlaps with the circumference of a virtual circle centered on the center CP of the through hole 140. As shown in FIG. 6, the outer peripheral surface 138a faces the radially inward direction of the rotor 110. The inner end of the washer 130, which is located radially inward of the rotor 110 from the center CP of the through hole 140 (see FIG. 7), is located on the outer peripheral surface 138a. The second part 138 is disposed radially inward of the first part 136 in the radial direction of the rotor 110. When the washer 130 is viewed from the rear side, the second portion 138 has a wider shape than the first portion 136 in the circumferential direction of the inner circumferential surface of the inner tubular member 98. The width of the second portion 138 in the circumferential direction of the rotor 110 is larger than the width of the first portion 136 in the circumferential direction of the rotor 110. A second distance L2 from the center CP (see FIG. 7) of the through hole 140 to the inner end of the second portion 138 in the radial direction of the rotor 110 is longer than a first distance L1 from the center CP (see FIG. 7) of the through hole 140 to the outer end of the first portion 136 in the radial direction of the rotor 110. In other words, as shown in FIG. 7, the first distance L1 from the center CP of the through hole 140 to the outer peripheral surface 142a of the semicircular portion 142 is shorter than the second distance L2 from the center CP of the through hole 140 to the outer peripheral surface 138a of the second portion 138. In this embodiment, the first distance L1 is half the second distance L2. In a modified example, the first distance L1 may be greater than half the second distance L2 or less than half the second distance L2.

As shown in FIG. 6, the inner tubular member 98 is formed with first recesses 148, 150 and protruding portions 152, 154. The first recesses 148, 150 are disposed on the rear end opening 102 side of the inner tubular member 98. The first recesses 148, 150 are recessed from the rear end surface of the inner tubular member 98 toward the front side. When the inner tubular member 98 is viewed from the rear side, the first recesses 148, 150 have a shape corresponding to the first portion 136 of the washer 130. The first recesses 148, 150 are disposed at intervals of 180 degrees from each other in the circumferential direction of the inner circumferential surface of the inner tubular member 98.

The overhanging portions 152, 154 overhang from the outer peripheral surface of the inner tubular member 98 toward the inner peripheral surface of the outer tubular member 80. As shown in FIG. 8, the overhanging amount of the overhanging portions 152, 154 decreases from the rear side to the front side. This makes it possible to suppress turbulence in the air flow along the outer peripheral surface of the inner tubular member 98. As shown in FIG. 6, each of the overhanging portions 152, 154 is disposed at a position corresponding to each of the first recesses 148, 150 in the circumferential direction of the inner peripheral surface of the inner tubular member 98. Each of the inner surfaces of the overhanging portions 152, 154 is formed to correspond to the shape of each of the first recesses 148, 150. The inner surfaces of the overhanging portions 152, 154 face the outer peripheral surface 142a of the semicircular portion 142.

Second recesses 156, 158 are formed on the rear end surface of the stator 112. The second recesses 156, 158 are recessed from the rear end surface of the stator 112 toward the front side. When the stator 112 is viewed from the rear side, the second recesses 156, 158 have a shape corresponding to the second portion 138 of the washer 130. The second recesses 156, 158 are arranged at intervals of 180 degrees from each other in the circumferential direction of the outer circumferential surface of the stator 112. The inner wall portions of the second recesses 156, 158 face the outer circumferential surface 138a of the second portion 138.

As shown in FIG. 8, the cover member 100 has a bottom portion 160, a side portion 162, protrusions 164, 166, and short fin portions 168, 170. The bottom portion 160 abuts against the rear end portion of the inner cylindrical member 98 from the rear side. As shown in FIG. 5, the bottom portion 160 closes the rear end opening 102 of the inner cylindrical member 98. The shaft 114 of the electric motor 106 penetrates the bottom portion 160. As shown in FIG. 8, a plurality of holes 161 are formed in the bottom portion 160. The side portion 162 extends from the periphery of the bottom portion 160 toward the front side. When the cover member 100 is attached to the inner cylindrical member 98, the side portion 162 is disposed outside the outer circumferential surface of the inner cylindrical member 98 and covers a part of the outer circumferential surface of the inner cylindrical member 98. The protrusions 164, 166 protrude from the vicinity of the front end of the outer peripheral surface of the side portion 162 toward the inner peripheral surface of the outer tubular member 80. The protrusions 164, 166 are arranged at intervals of 180 degrees in the circumferential direction of the outer peripheral surface of the side portion 162. The protrusions 164, 166 abut against the rear ends of the overhanging portions 152, 154 from the rear side. As a result, when the cover member 100 is attached to the inner tubular member 98, the first recesses 148, 150 and the rear ends of the overhanging portions 152, 154 are hidden and cannot be seen. The short fin portions 168, 170 are connected to the outer peripheral surface of the side portion 162 and the rear surfaces of the protrusions 164, 166. The short fin portions 168, 170 extend from the outer peripheral surface of the side portion 162 toward the inner peripheral surface of the outer tubular member 80. The short fins 168, 170 are disposed on the extension of the fins 96 that extend from the inner peripheral surface of the outer tubular member 80 toward the outer peripheral surface of the inner tubular member 98. Air flowing along the outer peripheral surface of the inner tubular member 98 flows along the multiple fins 96 and the short fins 168, 170, which helps prevent the air flow from becoming turbulent.

Next, a method of assembling the electric motor 106 to the motor housing 66 will be described. First, the manufacturer inserts the stator 112 into the inside of the inner tubular member 98 in a first direction (toward the front in this embodiment) from the rear end opening 102 of the inner tubular member 98. Next, as shown in FIG. 6, the manufacturer moves the stator 112 to a position where the second recesses 156, 158 face the first recesses 148, 150, respectively. Next, the manufacturer places the first portion 136 in the first recesses 148, 150, and places the second portion 138 in the second recesses 156, 158. Next, the manufacturer inserts the fastener 132 into the through hole 140 of the washer 130 and screws it into the inner tubular member 98. This fixes the washer 130 to the inner tubular member 98, and restricts the stator 112 from moving in the direction opposite the first direction from the rear end opening 102 of the inner tubular member 98 (toward the rear in this embodiment). Finally, the manufacturer inserts the rotor 110 and the shaft 114 into the inner tubular member 98, abuts the protrusions 164, 166 of the cover member 100 against the protrusions 152, 154, respectively, and screws the cover member 100 to the inner tubular member 98.

(effect)
The electric working machine 2 of this embodiment is equipped with an electric motor 106 having a rotor 110 and a stator 112 surrounding the rotor 110, a motor housing 66 having a rear end opening 102 in which the electric motor 106 is accommodated from the rear end opening 102, a washer 130 having a through hole 140 and abutting the stator 112 and the motor housing 66 from a first direction from the rear end opening 102 toward the electric motor 106, and restricting the stator 112 from moving in the direction opposite to the first direction relative to the motor housing 66, and a fastener 132 that is inserted into the through hole 140 to fix the washer 130 to the motor housing 66. 6 and 7, when the washer 130 fixed to the motor housing 66 is viewed in a first direction, a first distance L1 from the center CP of the through hole 140 to the outer end of the washer 130 in the radial direction of the rotor 110 is shorter than a second distance L2 from the center CP of the through hole 140 to the inner end of the washer 130 in the radial direction of the rotor 110. In this configuration, the amount by which the portion of the motor housing 66 that abuts against the washer 130 protrudes outward can be reduced compared to when a circular washer 130 is used. This allows the shape of the motor housing 66 to be further simplified.

6 and 7, the washer 130 includes a first portion 136 in which the through hole 140 is disposed, and a second portion 138 disposed radially inward of the first portion 136 in the rotor 110. The width of the second portion 138 in the circumferential direction of the rotor 110 is greater than the width of the first portion 136 in the circumferential direction of the rotor 110. In this configuration, compared to a case in which the width of the second portion 138 is the same as the width of the first portion 136, the area of the portion of the washer 130 facing the stator 112 can be sufficiently secured, and the stator 112 can be sufficiently prevented from slipping out of the motor housing 66.

As shown in FIG. 6, the motor housing 66 has first recesses 148, 150 having a shape corresponding to the shape of the first portion 136. The stator 112 has second recesses 156, 158 having a shape corresponding to the shape of the second portion 138. When the washer 130 is fixed to the motor housing 66, the first portion 136 is disposed in the first recesses 148, 150, and the second portion 138 is disposed in the second recesses 156, 158. In this configuration, when the washer 130 is fixed to the motor housing 66, it is necessary to adjust the orientation of the washer 130 so that the first portion 136 abuts against the motor housing 66 and the second portion 138 abuts against the stator 112. By disposing the first portion 136 in the first recesses 148, 150 and disposing the second portion 138 in the second recesses 156, 158, the orientation of the washer 130 can be easily adjusted.

The electric work machine 2 further includes a fan 108 driven by an electric motor 106, and an ejection nozzle 70 through which the air blown out by the fan 108 flows. The air caused by the rotation of the fan 108 flows along the motor housing 66. This electric work machine 2 functions as a blower. Since the air caused by the rotation of the fan 108 flows along the motor housing 66, if the motor housing 66 has a shape that protrudes outward, turbulence will occur in the air flow. With the above configuration, the amount of protrusion at the part of the motor housing 66 that abuts against the washer 130 can be reduced, thereby suppressing turbulence in the air flow.

(Correspondence)
The rear end opening 102 is an example of an "opening", and the front side is an example of a "first direction".

Second Example
A second embodiment will be described with reference to FIG. 9. In the second embodiment, only the points different from the first embodiment will be described, and points similar to those in the first embodiment will be denoted by the same reference numerals and will not be described. The second embodiment is different from the first embodiment in that the electric work machine 2 includes a battery pack B instead of the power cord 12. The battery pack B includes lithium ion battery cells. The power of the battery pack B is supplied to the electric motor 106. The battery pack B is detachably attached to the rear surface of the third housing 30. The battery pack B is attached to the third housing 30 by sliding the battery pack B to the right relative to the third housing 30, and is removed from the third housing 30 by sliding the battery pack B to the left relative to the third housing 30. In a modified example, the battery pack B may be attached to the third housing 30 by sliding the battery pack B downward relative to the third housing 30, and the battery pack B may be removed from the third housing 30 by sliding the battery pack B upward relative to the third housing 30. In addition, the battery pack B may be detachably attached to the first housing 26 or the second housing 28 .

In one embodiment, the inner tubular member 98 does not have to have the first recesses 148, 150. Also, the stator 112 does not have to have the second recesses 156, 158.

In one embodiment, the cross section of at least one of the first portion 136 and the second portion 138 of the washer 130 may have an elliptical, sector, or polygonal shape.

The electric work machine 2 according to one embodiment is not limited to a blower, but may be, for example, a chain saw or a lawn mower.

2: Electric work machine 10: Grip housing 14: Trigger 16: Cruise control lever 18: Control unit 66: Motor housing 68: Rear housing 70: Jet nozzle 80: Outer cylindrical member 96: Fin 98: Inner cylindrical member 100: Cover member 102: Rear end opening 106: Electric motor 108: Fan 110: Rotor 112: Stator 114: Shaft 130: Washer 132: Fastener 136: First portion 138: Second portion 138a, 142a: Outer peripheral surface 138b: Connection surface 140: Through hole 142: Semicircular portion 144: Rectangular portion 148, 150: First recess 152, 154: Protruding portion 156, 158: Second recess 160: Bottom portion 161: Hole 162 : Side portions 164, 166 : Protrusions 168, 170 : Short fin portions CP : Center

Claims (4)

An electric motor including a rotor and a stator surrounding the rotor;
a motor housing having an opening and receiving the electric motor through the opening;
two washers each having a through hole, the washers being brought into contact with the stator and the motor housing from a first direction from the opening toward the electric motor, and restricting the stator from moving relative to the motor housing in a direction opposite to the first direction;
a fastener inserted into the through hole to secure each of the two washers to the motor housing;
when each of the two washers fixed to the motor housing is viewed in the first direction, a distance from a center of the through hole in the radial direction of the rotor to an outer end of the washer is shorter than a distance from the center of the through hole in the radial direction of the rotor to an inner end of the washer,
An electric working machine, wherein when the two washers are fixed to the motor housing and viewed in the first direction, the two washers do not overlap in a direction extending radially outward from the rotational axis of the rotor. Each of the two washers comprises:
a first portion in which the through hole is disposed;
a second portion disposed radially inward of the first portion in the radial direction of the rotor,
The electric operating machine according to claim 1 , wherein a width of the second portion in a circumferential direction of the rotor is greater than a width of the first portion in the circumferential direction of the rotor. the motor housing has a first recess having a shape corresponding to a shape of the first portion,
the stator has a second recess having a shape corresponding to a shape of the second portion,
The electric operating machine according to claim 2 , wherein when the two washers are fixed to the motor housing, the first portion is disposed in the first recess and the second portion is disposed in the second recess. A fan driven by the electric motor;
and a blowout nozzle through which the air blown out by the fan flows,
The electric operating machine according to claim 1 , wherein air caused by rotation of the fan flows along the motor housing.