WO2023101021A1

WO2023101021A1 - Work machine

Info

Publication number: WO2023101021A1
Application number: PCT/JP2022/044624
Authority: WO
Inventors: 翔太平野; 賢伊縫; 啓伍伊勢田
Original assignee: 工機ホールディングス株式会社
Priority date: 2021-12-03
Filing date: 2022-12-02
Publication date: 2023-06-08

Abstract

The present invention allows easy assembly of a work machine. A work machine 10 comprises: a motor 11 having a stator 11a and a rotor 11d; a main housing 12 that is made of a resin, and stores the motor 11; a plunger 35 that is driven by the motor 11; a transmission mechanism 40 that transmits the power of the motor 11 to the plunger 35; and a transmission mechanism housing 23 that is made of a metal, and stores the transmission mechanism 40. A blade 17 is attached to the plunger 35. The transmission mechanism housing 23 has a stator support part that is located on an outer peripheral part of the stator 11a, and supports the stator 11a.

Description

work machine

The present invention relates to working machines.

As an example of a work machine, a work machine is known that includes an electric motor, an output section driven by the motor, and a transmission mechanism that transmits the power of the motor to the output section.

As a working machine as described above, for example, Patent Literature 1 discloses a working machine called a saver saw (also called a reciprocating saw) having a gear case capable of accommodating the transmission mechanism.

WO2019/130979

In the work machine (saber saw) described in Patent Document 1, a gear case (front housing) that houses a transmission mechanism, a motor case that houses a motor, and a handle case (rear housing) that houses electrical components other than the motor. and are configured as separate parts.

In such a work machine, the motor and the transmission mechanism are accommodated in separate housings (cases), so it is necessary to assemble the respective housings with high precision. If the housings are not assembled with high precision and the relative positions of the housings change, the axial accuracy of assembly deteriorates, and the operation of the motor and the transmission mechanism may be hindered.

In addition, since fasteners such as screws are required to assemble separate housings, there is a risk that the fasteners will increase the number of parts and increase costs. In addition, there is a concern that the work machine will become large due to the screw boss.

An object of the present invention is to provide a work machine having a suitable motor (stator) support structure. Another object of the present invention is to provide a work machine that can be easily assembled. Another object of the present invention is to provide a work machine capable of suppressing an increase in size.

A work machine according to the present invention includes a motor having a stator and a rotor, a resin main housing that houses the motor, an output section that is driven by the motor, and a transmission mechanism that transmits the power of the motor to the output section. a metal transmission mechanism housing comprising: a transmission mechanism accommodating portion that accommodates the transmission mechanism; and a stator support portion that is positioned on the outer periphery of the stator and supports the stator; and a main housing made of resin that accommodates the stator.

Another working machine of the present invention includes a motor having a stator and a rotor, a resin main housing containing the motor and having a regulating portion, an output portion driven by the motor, and the output portion. and a metal transmission mechanism housing containing the transmission mechanism and provided with a fitted portion, wherein the stator includes the motor While being fitted with the fitted portion in a direction along the rotation axis of , movement in a direction away from the transmission mechanism housing is restricted by the restricting portion.

According to the present invention, it is possible to realize a work machine having a suitable motor (stator) support structure. Furthermore, assembly can be easily performed in the work machine. Furthermore, it is possible to suppress an increase in size of the working machine.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which shows the structure of the working machine of embodiment of this invention. FIG. 2 is a side view showing the internal structure of the working machine of FIG. 1; FIG. 2 is a plan view showing the structure of the working machine of FIG. 1; FIG. 4 is a cross-sectional view showing the structure taken along line AA of FIG. 3; FIG. 2 is a perspective view showing the structure of a transmission mechanism housing assembled to the work machine of FIG. 1; FIG. 6 is a perspective view showing the structure of the transmission mechanism housing of FIG. 5 viewed from below; FIG. 2 is an exploded view showing the structure of a transmission mechanism assembled to the working machine of FIG. 1; FIG. 2 is an exploded view showing a support structure for a motor assembled to the work machine of FIG. 1; FIG. 2 is a perspective view showing the internal structure of a left main housing assembled to the work machine of FIG. 1; FIG. 2 is a cross-sectional view showing the support structure of the motor by the main housing in the work machine of FIG. 1, cut along the rotating shaft of the motor; FIG. 2 is a cross-sectional view showing a state in which the support structure of the stator by the transmission mechanism housing in the work machine of FIG. 1 is cut in a direction perpendicular to the rotating shaft of the motor and viewed from below; FIG. 2 is a cross-sectional view showing a state in which the supporting structure of the bearing holder by the transmission mechanism housing in the work machine of FIG. 1 is cut in a direction perpendicular to the rotating shaft of the motor and viewed from below; FIG. 2 is a cross-sectional view showing a cooling air passage in the work machine of FIG. 1;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same elements are denoted by the same reference numerals in a plurality of drawings used in the description of the present embodiment. In the present embodiment, as an example of a working machine, an electric working machine that drives a tip tool by an electric motor will be described.

A work machine 10 shown in FIGS. 1 to 4 is also called a saver saw, and has a blade 17 as a tip tool. The work machine 10 includes a motor 11 having a stator (a part of a current-carrying part) 11a and a rotor 11d, a main housing 12 made of resin that houses the motor 11, a plunger (output part) 35 that is driven by the motor 11, and a transmission mechanism 40 that transmits the power of the motor 11 to the plunger 35 . Motor 11 is a brushless motor.

The main housing 12 includes a body portion (upper portion) 12h, a motor case (lower portion) 15, a handle 14, and a mounting portion (power supply portion) 16. A transmission mechanism 40 is housed in the body portion 12h, and the motor case 15 The motor 11 is housed in the . The motor 11 has a stator 11a and a rotor 11d. The rotor 11d is integrated with the rotating shaft 11e, and the rotor 11d and the rotating shaft 11e are configured to rotate integrally. The rotating shaft 11e is rotatably supported by a bearing 27 located above and a bearing 28 located below. The rotor 11d is positioned inside the stator 11a. That is, the motor 11 is an inner rotor type motor. The upper end of the motor case 15 and the upper end of the handle 14 are connected to the body portion 12h, respectively, while the lower end of the motor case 15 and the lower end of the handle 14 are connected to the mounting portion 16, respectively. That is, the motor case 15 and the handle 14 extend downward from above substantially parallel to each other. A trigger 20 is provided at the upper end portion of the handle 14, and the mounting portion 16 is configured so that the battery pack 13 can be mounted thereon.

A blade 17 as a tip tool is attached to a blade attachment portion 19 provided at the tip of the plunger 35 . A base 18 is rotatably provided at the tip of the body portion 12h, and the workpiece is pressed against the base 18 during cutting.

The mounting portion 16 connected to the lower side of the motor case 15 is provided with a plurality of intake ports 15a as air inlets, while the body portion 12h connected to the upper side of the motor case 15 is provided with a plurality of air outlets. is provided with an exhaust port 15b. Therefore, the air taken in from the intake port 15a as cooling air passes through the inside of the motor case 15 and is discharged to the outside from the exhaust port 15b.

The main housing 12 is composed of a hard resin portion 12a and a soft resin portion 12b, and the hard resin portion 12a and the soft resin portion 12b are integrally formed. The hard resin portion 12a is made of synthetic resin such as polycarbonate, for example. On the other hand, the soft resin portion 12b is mainly arranged on the surface of a portion such as the handle 14 that requires gripping force, or a portion where there is concern that the main housing 12 side or the contact object may be damaged due to contact with materials or the ground. It is made of, for example, an elastomer material or the like. As shown in FIG. 3, the main housing 12 has a right main housing 12c and a left main housing 12d as left and right housing halves. Assembled. As shown in FIG. 9, support

portions

12e, 12f, and 12i that protrude inward (toward the transmission mechanism housing 23) are provided on the main body portion 12h of the main housing 12 and the inner wall of the motor case 15. As shown in FIG. The support portion 12e protruding from the inner surface of the main body portion 12h is positioned outside the transmission mechanism housing 23 radially outside the gear 29 accommodated in the transmission mechanism accommodation portion 23a. Positioning of the transmission mechanism housing 23 with respect to the main housing 12 is performed by abutting thereon. The transmission mechanism housing 23 positioned radially outwardly of the gear 29 is partially circular in conformity with the outer shape of the gear 29, and is supported by a support portion 12e consisting of a plurality of ribs spaced vertically and horizontally. Thus, the transmission mechanism housing 23 is preferably positioned. An air passage is formed between the ribs of the support portion 12e. A partition wall 12g is provided on the inner surface of the main housing 12. As shown in FIG. The partition wall 12 g is a wall (rib) that supports the transmission mechanism housing 23 . The partition wall 12g also functions as a wall portion that partitions the internal space of the main housing 12 in the front-rear direction. Although only the

support portions

12e, 12f, 12i and partition wall 12g of the left main housing 12d are shown in FIG. 9,

similar support portions

12e, 12f, 12i and partition wall 12g are formed in the right main housing 12c.

Further, as shown in FIG. 2, the work machine 10 is provided with a metal transmission mechanism housing 23 that accommodates a transmission mechanism 40 that transmits the power of the motor 11 shown in FIG. The transmission housing 23 is a single piece molded from a metal such as an aluminum alloy. The transmission mechanism housing 23 includes a transmission mechanism accommodating portion 23a that accommodates the transmission mechanism 40, and a stator support portion (fitted portion) 23b that is positioned on the outer periphery of the stator 11a and supports the stator 11a. Specifically, the transmission mechanism housing portion 23a and the stator support portion 23b are formed integrally, and the stator support portion 23b is a support portion extending from the transmission mechanism housing portion 23a toward the stator 11a side (downward side). . Therefore, the transmission mechanism housing 23 is a substantially L-shaped housing. A transmission mechanism accommodating portion 23 a that accommodates the transmission mechanism 40 is arranged inside the main body portion 12 h of the main housing 12 , and a stator support portion 23 b that supports the stator 11 a is arranged inside the motor case 15 of the main housing 12 . be. Although the details will be described later, the stator support portion 23b is also configured to position the rotor 11d and the rotating shaft 11e in the axial direction. Therefore, the stator support portion 23b can be said to be a motor support portion, and can also be said to be a rotor support portion. A trigger switch 20a is provided at the upper end of the handle 14 and operates in conjunction with the trigger 20. Further, the mounting portion 16 connected to the lower side of the motor case 15 has a trigger switch 20a for controlling the driving of the motor 11. A controller (energization section) 21 is provided. The trigger switch 20a and the controller 21 are electrically connected by a wiring 22 routed inside the handle 14 and the mounting portion 16, respectively.

In the working machine 10, as shown in FIG. 2, the transmission mechanism accommodating portion 23a of the transmission mechanism housing 23 is arranged inside the main body portion 12h, and the transmission mechanism is arranged inside the motor case 15 connected to the lower side of the main body portion 12h. A stator support portion 23b of the housing 23 is arranged. On the other hand, electrical components (current-carrying parts) such as wiring 22, controller 21, stator 11a, etc. are arranged over handle 14, mounting part 16 and motor case 15. As shown in FIG. Therefore, a transmission mechanism housing area 24 in which the transmission mechanism housing 23 is arranged and an electrical component accommodation area 25 in which electrical components such as the controller 21 and the stator 11a are arranged overlap within the motor case 15. . In other words, the transmission mechanism housing 23 covers the current-carrying section including at least one of the stator 11a and the controller 21 (in the working machine 10 of the present embodiment, the stator 11a is the transmission mechanism housing). 23 is covered by the stator support 23b). Therefore, at least part of the stator 11 a is covered by the transmission mechanism housing 23 and also covered by the main housing 12 . Further, the transmission mechanism housing 23 is entirely covered with the main housing 12 . Since a portion of the transmission mechanism housing region 24 and a portion of the electrical component housing region 25 overlap within the motor case 15, it is possible to prevent the working machine 10 from increasing in size. Further, in the case of the present embodiment, the entire transmission mechanism housing 23 is covered with the main housing 12, but a portion of the transmission mechanism housing 23 is covered with the main housing 12 and the other portion is covered with another housing. The transmission mechanism housing 23 may be configured to be housed therein, or may be configured so that the entire transmission mechanism housing 23 is housed in a separate housing that is a separate portion (separate member) from the main housing 12 . In this embodiment, since the entire transmission mechanism housing 23 is covered with the main housing 12, the number of parts can be reduced.

As shown in FIG. 4, the stator support portion 23b of the transmission mechanism housing 23 is provided with a stator 11a including a stator core 11b around which a stator coil 11c is wound and an insulator 11h made of an insulating member. A sensor substrate 21a mounted with a Hall IC for detecting the rotational position of the motor 11 (rotor 11d or rotating shaft 11e) is attached to the stator 11a (insulator 11h). Accordingly, the sensor substrate 21a is configured to be held by the transmission mechanism housing 23 (the stator support portion 23b). A pinion (not shown) is provided at the upper end of the rotating shaft 11 e configured to rotate integrally with the rotor 11 d , and the pinion is meshed with the gear 29 . The rotary shaft 11e is held by an upper bearing 27 at its upper portion and by a lower bearing 28 at its lower portion. That is, the lower bearing 28 provided on the rotating shaft 11e is supported by a bearing holder 26 made of resin. A centrifugal fan (fan) 51 for supplying air in the radial direction of the rotating shaft 11e is provided on the rotating shaft 11e of the motor 11. As shown in FIG. A fan guide 50 is provided on the stator 11a side of the centrifugal fan (fan) 51 to guide the flow of air.

A gear 29 meshing with the rotating shaft 11e of the motor 11 rotates about a rotating shaft 30 supported by the transmission mechanism accommodating portion 23a. The gear 29 is provided with a crank 34 that rotates together with the gear 29, and the crank 34 rotates eccentrically as the gear 29 rotates. Further, the crank 34 is provided with a plunger (output portion) 35, and when the crank 34 rotates eccentrically, the plunger 35 reciprocates. Further, the reciprocating motion of the plunger 35 causes the blade 17 attached to the blade attachment portion 19 at the tip of the plunger 35 to reciprocate. The reciprocating motion of the plunger 35 is guided by two rollers 36 provided inside the body portion 12h.

A counterweight 37 is provided at the upper end of the crank 34 . When the crank 34 rotates eccentrically, the counterweight 37 also reciprocates. At this time, the plunger 35 and the counterweight 37 are provided so as to operate 180 degrees out of phase with each other. For example, when the plunger 35 advances, the counterweight 37 retracts, and when the plunger 35 retracts, the counterweight 37 advances. Thereby, the counterweight 37 cancels out the vibration caused by the operation of the plunger 35 .

A plurality of steel balls 31 are arranged on the lower surface of the gear 29 , and the plurality of steel balls 31 are supported by strut washers 32 . Furthermore, a damper 33 is provided below the strut washer 32 . Therefore, the gear 29 tilts when receiving a reaction force, but the damper 33 is structured to absorb the reaction force, thereby suppressing the gear 29 from tilting.

Further, the rotating shaft 11e of the motor 11 and the gear 29 are meshed by a helical gear. configured to be granted. In the work machine 10, the lower end of the rotating shaft 11e of the motor 11 is supported by the bearing holder 26 via the lower bearing 28, but when the load is high, the rotating shaft 11e is pulled upward, so the bearing The holder 26 is not disengaged by being biased downward, and the support structure for the motor 11 is structured so as not to be easily disassembled.

Further, the battery pack 13 contains a plurality of battery cells 13a and power is supplied from the battery pack 13 to the motor 11 . When the trigger 20 of the handle 14 is operated by the operator, the trigger switch 20a incorporated in the handle 14 is actuated, the power for the cutting operation is output from the controller 21, and the motor current is supplied to the motor 11. . As a result, the motor 11 operates, and when the crank 34 rotates eccentrically due to the rotation of the gear 29, the plunger 35 reciprocates (moves back and forth). As a result, the blade 17 attached to the tip of the plunger 35 reciprocates (moves back and forth) to perform cutting. The motor 11 is a brushless motor, and the controller 21 is equipped with a plurality of switching elements (inverter circuits) for controlling the motor 11 and a control section (microcontroller) for on/off controlling the switching elements.

Next, the detailed structure of the transmission mechanism housing 23 assembled to the working machine 10 will be described. As shown in FIGS. 5 and 6, the transmission mechanism housing 23 is a metal housing integrally formed with a transmission mechanism accommodating portion 23a arranged in the upper portion and a stator support portion 23b arranged in the lower portion. It is composed of a box-shaped (container-shaped) transmission mechanism accommodating portion 23a and an annular (cylindrical)-shaped stator support portion 23b. That is, the transmission mechanism accommodating portion 23a and the stator support portion 23b are each part of a single component (the transmission mechanism housing 23) and are configured inseparably. The stator support portion 23b extends downward from the transmission mechanism housing portion 23a. The transmission mechanism housing portion 23a houses the transmission mechanism 40, and the stator support portion 23b supports the stator 11a. there is As shown in FIG. 5, a side wall 23c of the transmission mechanism accommodating portion 23a is provided with a plurality of screw bosses 23d. is screwed. A plurality of ribs 23c1 are formed on the side wall 23c. Further, as shown in FIG. 6, a bearing portion 23j that supports the rotating shaft 11e of the motor 11 and a bearing portion 23k that supports the rotating shaft 30 of the gear 29 are provided at the bottom of the transmission mechanism accommodating portion 23a. ing. The bearing portion 23j has a circular motor shaft opening 23g in which the rotary shaft 11e is arranged, and the bearing portion 23k has a circular transmission mechanism shaft opening 23h in which the rotary shaft 30 is arranged. The bearing portion 23j and the bearing portion 23k are provided with a plurality of

ribs

23e and 23f extending in the radial direction of the respective

rotating shafts

11e and 30, and have a circular motor shaft opening 23g and a circular transmission mechanism shaft opening. The center positions of the portions 23h are ensured with high accuracy so as not to shift.

Next, the structure of transmission mechanism 40 in work machine 10 will be described in detail with reference to FIG. At least a gear 29 as a transmission mechanism 40 and an eccentrically rotating crank 34 attached to the gear 29 are provided in the transmission mechanism accommodating portion 23 a of the transmission mechanism housing 23 . Further, the crank 34 is provided with a plunger 35 as an output portion via a sleeve 41 . More specifically, the crank 34 is engaged with the hole 35a of the plunger 35 via the sleeve 41, and when the crank 34 rotates eccentrically due to the rotation of the gear 29, the plunger 35 reciprocates. A blade attachment portion 19 is provided at the tip of the plunger 35 via an O-ring 39 , and a blade 17 is attached to the blade attachment portion 19 covered with a dust guard 38 . The plunger 35 reciprocates with its tip portion guided by a roller 36 . The O-ring 39 is held in a groove formed in the front end portion of the transmission mechanism housing 23 .

A plurality of steel balls 31 are arranged in a circle on the lower surface side of the gear 29 . These steel balls 31 are supported by strut washers 32 and are in contact with the lower surface of the gear 29 . Furthermore, a damper 33 is provided below the strut washer 32 . As a result, the damper 33 absorbs the reaction force that the gear 29 receives, and the inclination of the gear 29 can be suppressed.

The plunger 35 is supported by guide members 42 arranged on both left and right sides so as to be able to reciprocate on guide members 42 attached via bolts 35b. A groove is formed inside the guide member 42, and the side portion of the plunger 35 is inserted into this groove. Thereby, the plunger 35 is supported by the left and right guide members 42 so as to be able to reciprocate (back and forth).

A counterweight 37 is provided at the upper end of the crank 34 and operates 180 degrees out of phase with the plunger 35 . That is, when the crank 34 rotates eccentrically, the counterweight 37 also reciprocates, so that the counterweight 37 cancels the vibration caused by the operation of the plunger 35 . The counterweight 37 is reciprocally supported by metal guides 46 arranged on both left and right sides, and each guide 46 is supported by a rubber damper 47 . As a result, the damper 47 absorbs the vibration of the counterweight 37 when it moves. The left and right guides 46 are supported by spacers 43, respectively, and a metal plate 44 for pressing the guide member 42 of the plunger 35 is tightened from above by bolts 44a. The counterweight 37 is supported by guides 46 via a plurality of steel balls 45 arranged in grooves 37b formed on the side surfaces of the counterweight 37. As shown in FIG. That is, a plurality of steel balls 45 are sandwiched between guides 46 provided on both left and right sides of the counterweight 37, and the guides 46 can reciprocate (forward and backward) through the plurality of steel balls 45. supported by A plurality of steel balls 45 are also arranged in the holes 37 a on the upper surface of the counterweight 37 , and these steel balls 45 are pressed by the upper cover 49 of the transmission mechanism housing 23 . That is, when the upper cover 49 of the transmission mechanism housing 23 is fixed with a plurality of bolts 49a via a frame-shaped sealing member 48, the plurality of steel balls 45 arranged on the upper surface of the counterweight 37 come into contact with the upper cover 49. , thereby positioning the counterweight 37 .

As described above, in the work machine 10, the stator 11a is directly supported by the transmission mechanism housing 23 made of metal. Accordingly, assembly of the housing can be easily performed without requiring high assembly accuracy.

Further, since the transmission mechanism accommodating portion 23a that accommodates the transmission mechanism 40 and the stator support portion 23b that supports the stator 11a are integrally molded, screws for assembling these two housings are not required. Therefore, since the number of screw bosses can also be reduced, it is possible to suppress an increase in the size of work machine 10 due to the provision of screw bosses. Furthermore, since the number of screws can be reduced, cost reduction of the work machine 10 can be achieved.

The stator support portion 23b includes a plurality of extension portions 23b1 extending downward (toward the stator 11a) from the transmission mechanism housing portion 23a, a connection portion 23b2 connecting the two extension portions 23b1, and an extension portion 23b1. and a connecting portion 23b2, a rib 23b4 provided on the outer side of the extending portion 23b1, and a fitted portion 23b5 provided on the inner side of the extending portion 23b1. A total of four extending portions 23b1 are formed, two on the left side of the transmission mechanism housing 23 and two on the right side. The connection portion 23b2 is connected to the lower ends of the two extending portions 23b1 located on the left side or the right side and spaced apart in the front-rear direction. The connecting portion 23b2 is formed in a substantially arc shape (partially annular shape). The opening 23b3 is a space that communicates the inside and the outside of the stator support portion 23b. The opening 23b3 serves as a path for air sent from the centrifugal fan 51. As shown in FIG. The opening 23b3 is an opening (space) surrounded by the extending portion 23b1 and the connecting portion 23b2 and extending in a direction parallel to the rotating shaft 11e. The opening 23 b 3 also functions as a thinned portion for reducing the weight of the transmission mechanism housing 23 . The rib 23b4 is a portion that engages with the main housing 12. As shown in FIG. The rib 23b4 also functions as a reinforcing rib that makes it difficult for the extending portion 23b1 to bend in the left-right direction. The fitted portion 23b5 is a portion of the extending portion 23b1 that is recessed toward the outside, and is a portion that fits (engages) with the stator 11a directly or indirectly. Due to the recessed fitted portion 23b5, a step is generated at the upper end portion of the fitted portion 23b5, and this portion serves as an abutment portion 23b6 against which a fan guide 50 (to be described later) abuts. The abutting portion 23b6 is provided on each of the four extending portions 23b1.

Next, assembly of the stator 11a and the rotor 11d (rotary shaft portion) to the stator support portion 23b of the transmission mechanism housing 23 will be described with reference to FIGS. 8 to 10. FIG. First, the rotor 11d, the rotating shaft 11e, the centrifugal fan 51, the bearing 27, and the bearing 28 are unitized (as a rotating shaft portion). Next, the unitized bearing 27 is attached to the transmission mechanism housing 23 . Thus, the rotor 11 d , the rotating shaft 11 e and the centrifugal fan 51 are held by the transmission mechanism housing 23 . Next, with the fan guide (positioning member) 50 fitted to the outer periphery of the stator 11a, the fan guide 50 and the fitted portion 23b5 are fitted from the lower side of the stator support portion 23b. That is, the stator 11a is inserted in the direction (vertical direction) along the rotating shaft 11e of the motor 11 and fitted with the stator support portion 23b (fitted portion 23b5). Specifically, the four support portions 50a of the ring-shaped fan guide 50 that guides the air flow generated by the centrifugal fan 51 are press-fitted inside the stator support portion 23b (fitted portion 23b5). The stator 11a is fitted to the fan guide 50 (supporting portion 50a) fitted to the stator supporting portion 23b. For this reason, a chamfered portion 50c is formed on the outer surface (upper end) of the support portion 50a of the fan guide 50 so that it can be easily fitted into the stator support portion 23b. The ring-shaped fan guide 50 is partially formed with a notch 50b for an air passage. As shown in FIG. 10, the fan guide 50 inserted (fitted) into the stator support portion 23b (fitted portion 23b5) abuts against the abutting portion 23b6 of the stator support portion 23b, thereby preventing upward movement. Regulated.

After the support portion 50a of the fan guide 50 and the stator 11a are fitted inside the stator support portion 23b, the bearing holder 26 made of resin is fitted inside the annular stator support portion 23b from below. At this time, a chamfered portion 26b is also formed on the outer surface of the support portion 26a of the bearing holder 26 so that it can be easily fitted into the stator support portion 23b (fitted portion 23b5). As described above, the stator support portion 23 b is provided so as to cover the support portion 50 a of the fan guide 50 and the support portion 26 a of the bearing holder 26 . Here, both the transmission mechanism housing 23 and the stator core 11b are made of metal, and when the stator core 11b is directly press-fitted into the transmission mechanism housing 23, the metals are fitted together. can be difficult to do. The support portion 50a of the fan guide 50 and the support portion 26a of the bearing holder 26 are each made of resin, and are easily crushable compared to the transmission mechanism housing 23 and the stator core 11b. In the case of the present embodiment, since the resin positioning member (fan guide 50) is interposed between the stator support portion 23b (transmission mechanism housing 23) and the stator 11a, press fitting can be easily performed by crushing the positioning member. This makes it easier for a person to manually insert the stator core 11b into the stator support portion 23b. Furthermore, since the chamfered

portions

50c and 26b are formed, fitting with the stator support portion 23b can be performed smoothly. In the case of the present embodiment, an electrically insulating (made of resin) positioning member is interposed between the stator 11a and the transmission mechanism housing 23 (stator support portion 23b). In other words, the stator 11a is supported by the transmission mechanism housing 23 via an insulating member. More specifically, an insulating fan guide 50 is interposed between the stator 11 a and the transmission mechanism housing 23 . In this way, while the transmission mechanism housing 23 supports the stator 11a, it is possible to electrically insulate between the stator 11a having the conducting portion and the transmission mechanism housing 23 made of metal. In addition, by fitting (pressing) the stator 11a into the stator support portion 23b, the extension portion 23b1 of the stator support portion 23b moves radially around the rotation shaft 11e (a direction along a plane extending in the front, rear, left, and right directions). ), it tries to deform in this direction, but since the connecting portion 23b2 connects the extending portions 23b1, the extending portions 23b1 are restrained from being relatively separated from each other. Thus, the extension portion 23b1 (fitted portion 23b5) can be prevented from being separated from the stator 11a.

After fitting the stator 11a with the stator support portion 23b, when the bearing holder 26 is fitted into the stator support portion 23b from below, the upper end portion of the support portion 26a of the bearing holder 26 abuts against the stator core 11b (Fig. 10). Thereby, the bearing holder 26 is positioned, and as a result, the stator 11a is positioned to the stator support portion 23b. Moreover, the bearing 28 is fitted into the bearing holder 26 by this fitting, whereby the rotating shaft 11e and the bearing 28 are axially positioned. That is, the bearing 28 is held by the bearing holder 26 held by the stator support portion 23b, and the rotation shaft 11e is positioned in the axial and radial directions.

As described above, in the work machine 10, a positioning member for positioning the stator 11a is provided on the outer peripheral portion of the stator 11a, and the stator 11a is supported by the stator support portion 23b of the transmission mechanism housing 23 via the positioning member. be. In the work machine 10, a fan guide 50 that serves as a guide for the centrifugal fan 51 and a bearing holder 26 that holds the lower bearing 28 are provided as positioning members for the stator 11a. That is, the stator 11a is supported by the stator support portion 23b of the transmission mechanism housing 23 without using fasteners such as screws. In other words, the stator 11a is supported by the stator support portion 23b of the transmission mechanism housing 23 by fitting. By using the fan guide 50 and the bearing holder 26 as positioning members for the stator 11a, the parts can be shared, and the cost of the work machine 10 can be reduced. Further, there is no need to provide a detent structure for the stator 11a or the transmission mechanism housing 23, and the structure around the motor can be simplified. The upper bearing 27 is fixed by a bearing lock 27a, and the lower bearing 28 is fixed by a bearing lock 28a. The stator 11a and the rotating shaft (rotor 11d, rotating shaft 11e, etc.) are held in the transmission mechanism housing 23 by a certain amount of holding force in the axial direction (vertical direction) by press-fitting or bearing locking. When it is urged in the direction, it is detached from the stator support portion 23b. That is, at this stage (before being housed in the main housing 12), the stator 11a and the rotary shaft (rotor 11d, rotary shaft 11e, etc.) can be pulled out of the transmission mechanism housing 23 if they are strongly pulled downward. In the present application, as described below, the main housing 12 regulates axial movement of the stator 11a and the rotating shaft portion (rotor 11d, rotating shaft 11e, etc.).

After fitting the bearing holder 26, when the right side main housing 12c and the left side main housing 12d shown in FIG. 3 are assembled, as shown in FIG. The support portion 12f that has been pushed in is entered. That is, the support portion 12f of the main housing 12 abuts against the lower end of the bearing holder 26. As shown in FIG. As a result, the bearing holder 26 does not come off downward (downward movement is restricted). Here, the support portion 12f of the main housing 12 is a restricting portion that restricts movement of the stator 11a in the direction away from the transmission mechanism 40 (the downward direction). The lower end of the stator support portion 23b also abuts on the support portion 12f. Therefore, when the right main housing 12c and the left main housing 12d are assembled, the bearing holder 26 is supported from below by the support portion 12f of the main housing 12, and the transmission mechanism housing 23 is also supported by the

support portions

12e and 12i of the main housing 12. Supported by The bearing holder 26 axially supports a bearing 28 that supports the rotating shaft 11e, and axially supports the stator 11a (stator core 11b) from bottom to top. Therefore, when the bearing holder 26 is restricted from moving downward, the downward movement of the rotating shaft 11e and the stator 11a is also restricted. In other words, by assembling the right main housing 12c and the left main housing 12d, fixing the positions of the stator 11a and the rotor 11d is completed. In other words, the stator 11a is fixed to the transmission mechanism housing 23 by screws for assembling the right main housing 12c and the left main housing 12d.

Next, detents of the stator 11a in the work machine 10 will be described. FIG. 11 is a bottom view of a section around the stator support portion 23b in the front, rear, left, and right directions at a position below the support portion 12f. As shown in FIG. 11, the outer peripheral portion of the stator 11a is formed with four protrusions 11f projecting outward in the circumferential direction. The support portion 50a of the fan guide 50 is fitted so as to cover each of these four projections 11f, and is engaged in the clockwise and counterclockwise directions in FIG. 11 (rotation prevention portion S2). . Furthermore, the stator support portion 23b of the transmission mechanism housing 23 is fitted so as to cover the four support portions 50a at each of the four support portions 50a, and engages in the clockwise and counterclockwise directions in FIG. ing. As a result, the fan guide 50 is prevented from rotating by the transmission mechanism housing 23 and the stator 11a is prevented from rotating by the fan guide 50 . Further, the rotation of the transmission mechanism housing 23 with respect to the main housing 12 is also prevented by engaging the rib 23b4 provided on the outside of the extension portion 23b1 with (the concave portion of) the support portion 12f. The ribs 23b4 are provided on each of the four extending portions 23b1, and are engaged with the support portion 12f at a total of four locations, two on each side.

The fan guide 50 is provided with a protrusion 50d, and a recess 11g is provided on the outer periphery of the stator 11a. In addition, it is possible to prevent the stator 11a from being incorrectly assembled with respect to the fan guide 50 (the anti-rotation portion S1).

Next, the anti-rotation of the bearing holder 26 in the work machine 10 will be described. FIG. 12 is a bottom view of a cross section in the front, rear, left, and right directions at a position just above the bearing 28. FIG. As shown in FIG. 12, a chamfered portion 26b is formed on each of the four support portions 26a of the bearing holder 26. As shown in FIG. On the other hand, projections 23b7 are formed at four locations (fitted portions 23b5) corresponding to the circumferential support portions 26a of the stator support portion 23b of the transmission mechanism housing 23. The rotation of the bearing holder 26 can be prevented by engaging the protrusions 23b7 of the stator support portion 23b at four locations (rotation prevention portions S3). More specifically, the front left and rear right protrusions 23b7 with respect to the rotation shaft 11e restrict the clockwise rotation of the bearing holder 26 in FIG. The protrusion 23b7 restricts the counterclockwise rotation of the bearing holder 26 in FIG.

Next, the cooling air passage in work machine 10 will be described. As shown in FIG. 13, the rotation of the centrifugal fan 51 provided on the rotating shaft 11e of the motor 11 generates a negative pressure below the centrifugal fan 51, and air (outside air) is taken into the working machine 10. . Specifically, air is taken in from the intake port 15 a of the main housing 12 (air passage 52 ), mainly passes through the inside of the stator 11 a and reaches the centrifugal fan 51 . Then, the air reaching the centrifugal fan 51 is blown radially outward by the centrifugal fan 51 . The air blown radially outward by the centrifugal fan 51 hits the inner wall of the main housing 12 and is guided in the moving direction. Here, since the support portion 12i and the fan guide 50 are provided below the centrifugal fan 51, the air hitting the inner wall of the main housing 12 is suppressed from flowing downward. Therefore, the air hitting the inner wall of the main housing 12 mainly flows upward. The air that is blown upward by the centrifugal fan 51 passes through the side surface of the transmission mechanism housing 23 and then exits through the exhaust port 15b of the main housing 12 (air passage 54). The space outside the transmission mechanism accommodating portion 23a in the left-right direction is partitioned in the front-rear direction by the partition wall 12g, so that the air blown from the centrifugal fan 51 does not flow forward. Further, since the fan guide 50 is formed with the notch 50b, the air passing through the outer periphery of the stator 11a can flow into the centrifugal fan 51 through the notch 50b (air passage 53).

Here, an air passage is required to allow air to flow from the centrifugal fan 51 covered by the stator support portion 23b to the outside of the transmission mechanism housing 23 . Therefore, in the present embodiment, the stator support portion 23b is provided with an opening portion 23b3 that is an opening penetrating in the radial direction (horizontal direction). For example, if the stator support portion 23b has a tubular shape without a hole, it becomes difficult to flow air to the outside of the transmission mechanism housing 23, but in the case of the present embodiment, it is possible to create an air passage by the opening portion 23b3. can. In particular, since the opening 23b3 is positioned radially outward of the centrifugal fan 51, the air from the centrifugal fan 51 is immediately sent to the outside of the transmission mechanism housing 23, so that the air flows smoothly. Alternatively, the air from the centrifugal fan 51 may first pass through the transmission mechanism housing 23 and then be discharged to the outside of the transmission mechanism housing 23 through a through hole or the like. In this case, for example, it is assumed that a through hole serving as an air passage is provided above the centrifugal fan 51, but the transmission mechanism accommodating portion 23a filled with lubricant (grease) is positioned immediately above the stator support portion 23b. Therefore, it is necessary to offset the position of the stator support portion 23b (stator 11a) slightly downward, which may lead to an increase in the size of the main body. Therefore, the configuration of the present application in which the opening 23b3 is positioned radially outward of the centrifugal fan 51 is more suitable for the working machine.

Thereby, the stator 11a and the transmission mechanism housing 23 can be cooled. The intake port 15a and the exhaust port 15b are provided in the right main housing 12c and the left main housing 12d, respectively, so that cooling air can be supplied to the left and right sides of the stator 11a and the transmission mechanism housing 23, respectively. Further, a plurality of ribs 23c1 are formed on the side wall 23c of the transmission mechanism housing 23. These ribs function as radiating fins, and air flows outside the ribs 23c1, so that the transmission mechanism housing 23 can be cooled appropriately. can be done.

The present invention is not limited to the above embodiments, and can be modified in various ways without departing from the scope of the invention. For example, in the above embodiment, the stator support portion 23b is positioned below the transmission mechanism housing 23. However, the stator support portion 23b (stator 11a) is positioned behind the transmission mechanism housing 23. You can Also, although the form of the saber saw has been described as the work machine, the present invention can be applied to work machines such as grinders and jigsaws that use a metal transmission mechanism housing. The present invention can also be applied to a system that uses an AC power supply instead of a battery pack (battery), that is, a system that has a power cord. Also, although the number of extension portions 23b1 is four, it may be more or less. Further, although the main housing 12 is composed of the hard resin portion 12a and the soft resin portion 12b, it may be composed of only the hard resin portion.

DESCRIPTION OF SYMBOLS 10... Working machine, 11... Motor, 11a... Stator (energization part), 11b... Stator core, 11c... Stator coil, 11d... Rotor, 11e... Rotating shaft, 11f... Convex part, 11g... Concave part, 12... Main housing, 12a Hard resin portion 12b Soft resin portion 12c Right main housing 12d Left main housing 12e Supporting portion 12f Supporting portion (restriction portion) 12g Partition wall

12h Body portion

12i Supporting portion 13 Battery pack 13a Battery cell 14 Handle 15 Motor case

15a Intake port

15b Exhaust port 16 Mounting part 17 Blade 18 Base 19 Blade mounting part 20 Trigger 20a Trigger switch 21 Controller (energizing portion) 21a Sensor substrate 22 Wiring 23 Transmission mechanism housing 23a Transmission mechanism accommodating portion 23b Stator support portion (fitted portion) 23c side wall

23d screw boss

23e, 23f rib 23g motor shaft opening 23h transmission mechanism shaft opening 23b7 protrusion 23j, 23k bearing 24 transmission mechanism housing region , 25... Electric component housing area 26... Bearing holder (positioning member) 26a... Support part 26b... Chamfered part 27... Upper bearing 27a... Bearing lock 28... Lower bearing 28a... Bearing lock 29... Gear 30 Rotating shaft 31 Steel ball 32 Struct washer 33 Damper 34 Crank 35 Plunger (output part) 35a Hole 35b Bolt 36 Roller 37 Counterweight , 37a... hole, 37b... groove, 38... dust guard, 39... O-ring, 40... transmission mechanism, 41... sleeve, 42... guide member, 43... spacer, 44... metal plate, 44a... bolt, 45... steel Ball 46 Guide 47 Damper 48 Sealing material 49 Top cover 49a Bolt 50 Fan guide (positioning member) 50a Supporting part 50b Notch 50c Chamfer 50d Protrusions 51... Centrifugal fan (fan) 52, 53, 54... Air passages S1, S2, S3... Detent parts

Claims

a motor having a stator and a rotor;
an output driven by the motor;
a transmission mechanism that transmits power of the motor to the output unit;
a metal transmission mechanism housing including a transmission mechanism accommodating portion that accommodates the transmission mechanism; and a stator support portion that is positioned on the outer periphery of the stator and supports the stator;
a main housing made of resin that accommodates the stator supported by the stator support portion.
a motor having a stator and a rotor;
a resin main housing containing the motor and provided with a restricting portion;
an output driven by the motor;
a transmission mechanism that transmits power of the motor to the output unit;
a metal transmission mechanism housing containing the transmission mechanism and having a fitted portion;
A work machine having
The stator is a work machine that is fitted with the fitted portion in a direction along the rotation shaft of the motor, and is restricted from moving in a direction away from the transmission mechanism housing by the restricting portion.
The working machine according to claim 1, wherein the main housing includes a restricting portion that restricts movement of the stator in a direction away from the transmission mechanism.
The working machine according to claim 1, wherein the stator support portion extends from the transmission mechanism housing portion toward the stator side.
having a controller for controlling driving of the motor;
The work machine according to claim 1 or 2, wherein the transmission mechanism housing covers a current-carrying section including at least one of the stator and the controller.
The working machine according to claim 1 or 2, wherein at least part of said stator is covered by said transmission mechanism housing and is covered by said main housing.
The working machine according to claim 6, wherein part or all of said transmission mechanism housing is covered with said main housing.
A positioning member for positioning the stator is provided on the outer peripheral portion of the stator,
3. The working machine according to claim 1, wherein said stator is supported by said transmission mechanism housing via said positioning member.
A fan is provided on the rotating shaft of the motor,
The working machine according to claim 8, wherein the positioning member is a fan guide that supports the fan.
A bearing is provided on the rotating shaft of the motor,
The working machine according to claim 8, wherein the positioning member is a bearing holder that holds the bearing.
The work machine according to claim 8, wherein the positioning member is a resin member.
3. The working machine according to claim 1, wherein said stator is supported by said transmission mechanism housing via an insulating member.
The working machine according to claim 1, wherein the stator support portion is provided with an opening penetrating through the stator in a radial direction.
having a fan rotated by the motor;
14. The working machine according to claim 13, wherein the opening is configured to be an air passage when the fan rotates.
The work machine according to claim 1, wherein the motor supported by the transmission mechanism housing is housed in the main housing.