Work equipment

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

Technical Field

[0001] The present invention relates to a working machine.

Background Art

[0002] As an example of a working machine, there is known a working machine including an electric motor, an output unit driven by the motor, and a transmission mechanism that transmits the power of the motor to the output unit.

[0003] As a working machine as described above, for example, Patent Document 1 discloses a working machine, also called a saber saw (reciprocating saw), including a gear case capable of accommodating the transmission mechanism.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the working machine (saber saw) described in Patent Document 1 above, a gear case (front housing) that accommodates the transmission mechanism, a motor case that accommodates the motor, and a handle case (rear housing) that accommodates electrical components other than the motor are each configured as separate components.

[0006] In such a working machine, since the motor and the transmission mechanism are accommodated in separate housings (cases), it is necessary to assemble each housing with high precision. If the relative positions of the respective housings change without being accurately assembled, the axial accuracy of the assembly deteriorates, which may interfere with the operation of the motor and the transmission mechanism.

[0007] Furthermore, since screws or other fasteners are required to assemble the separate housings, there is a risk of increased parts count and costs due to the fasteners. Additionally, there is concern that the screw bosses may lead to a larger work machine.

[0008] The object of the present invention is to provide a work machine having a suitable motor (stator) support configuration. Furthermore, to provide a work machine that can be easily assembled. Furthermore, to provide a work machine that can suppress an increase in size. [Means for solving the problem]

[0009] The present invention provides a work machine comprising: a motor having a stator and a rotor; an output unit driven by the motor and to which a cutting tool can be attached; a transmission mechanism for transmitting power from the motor to the output unit; a metal transmission mechanism housing comprising a resin positioning member made of resin that abuts against the side surface of the stator; a transmission mechanism housing for housing the transmission mechanism; and a stator support portion located on the outer circumference of the stator and supporting the stator via the positioning member; and a resin main housing that houses the stator support portion and the stator supported by the stator support portion, and has a handle portion that can be gripped by an operator, and while gripping the handle portion, the cutting tool is applied to the workpiece. Press against This makes it possible to perform the processing, and the stator is held in the stator support by press-fitting via the positioning member.

[0010] Furthermore, another work machine of the present invention comprises a motor having a stator and a rotor that rotates about an axis in a first direction; a resin main housing that houses the motor and has a handle portion and a restricting portion that can be gripped by an operator; an output portion driven by the motor and to which a tip tool can be attached; a transmission mechanism that transmits the power of the motor to the output portion; and a metal transmission mechanism housing that houses the transmission mechanism and has a fitting portion, wherein the operator grips the handle portion and moves the tip tool to the workpiece. Press againstThis makes it possible to perform the machining, and the restricting portion extends from the inner surface of the main housing and overlaps with the stator at least in part when viewed in the first direction, and the stator is fitted with the fitted portion in a direction toward one side in the first direction, and the restricting portion This is in a direction away from the transmission mechanism housing. Movement in the direction toward the other side of the first direction is restricted. [Effects of the Invention]

[0011] According to the present invention, a work machine having a suitable motor (stator) support configuration can be realized. Furthermore, assembly of the work machine can be easily performed. In addition, the size of the work machine can be suppressed. [Brief explanation of the drawing]

[0012] [Figure 1] This is a perspective view showing the structure of a work machine according to an embodiment of the present invention. [Figure 2] Figure 1 is a side view showing the internal structure of the work machine. [Figure 3] Figure 1 is a plan view showing the structure of the work machine. [Figure 4] This is a cross-sectional view showing the structure cut along line AA in Figure 3. [Figure 5] Figure 1 is a perspective view showing the structure of the transmission mechanism housing that is assembled to the work machine. [Figure 6] Figure 5 is a perspective view showing the structure of the transmission mechanism housing as seen from below. [Figure 7] This is an exploded view showing the structure of the transmission mechanism to be assembled to the work machine shown in Figure 1. [Figure 8] This is an exploded view showing the support structure for the motor that will be assembled to the work machine shown in Figure 1. [Figure 9] Figure 1 is a perspective view showing the internal structure of the left main housing as it is assembled to the work machine. [Figure 10] Figure 1 is a cross-sectional view showing the motor support structure by the main housing in the work machine, cut along the rotation axis of the motor. [Figure 11]FIG. 1 is a cross-sectional view showing a state in which the support structure of the stator by the transmission mechanism housing in the working machine is cut in a direction orthogonal to the rotation axis of the motor and viewed from below. [Figure 12] FIG. 1 is a cross-sectional view showing a state in which the support structure of the bearing holder by the transmission mechanism housing in the working machine is cut in a direction orthogonal to the rotation axis of the motor and viewed from below. [Figure 13] FIG. 1 is a cross-sectional view showing a cooling air passage in the working machine.

BEST MODE FOR CARRYING OUT THE INVENTION

[0013] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the plurality of drawings used in the description of this embodiment, the same elements are denoted by the same reference numerals. In this embodiment, as an example of a working machine, an electric working machine in which a tip tool is driven by an electric motor will be described.

[0014] The working machine 10 shown in FIGS. 1 to 4, also called a saber saw, has a blade 17 attached as a tip tool. The working machine 10 includes a motor 11 having a stator (a part of the energization unit) 11a and a rotor 11d, a resin main housing 12 that houses the motor 11, a plunger (output unit) 35 driven by the motor 11, and a transmission mechanism 40 that transmits the power of the motor 11 to the plunger 35. The motor 11 is a brushless motor.

[0015] The main housing 12 includes a main body part (upper part) 12h, a motor case (lower part) 15, a handle 14, and a mounting part (power supply part) 16. A transmission mechanism 40 is accommodated in the main body part 12h, and a motor 11 is accommodated in the motor case 15. The motor 11 has a stator 11a and a rotor 11d. The rotor 11d is integrated with a 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 on the upper side and a bearing 28 located on the lower side. The rotor 11d is located inside the stator 11a. That is, the motor 11 is an inner rotor type motor. The upper end part of the motor case 15 and the upper end part of the handle 14 are respectively connected to the main body part 12h, while the lower end part of the motor case 15 and the lower end part of the handle 14 are respectively connected to the mounting part 16. That is, the motor case 15 and the handle 14 extend from above to below substantially parallel to each other. A trigger 20 is provided at the upper end part of the handle 14, and the mounting part 16 is configured such that a battery pack 13 can be mounted.

[0016] The blade 17, which is a tip tool, is attached to a blade attachment part 19 provided at the tip of a plunger 35. A base 18 is provided rotatably at the tip of the main body part 12h, and during cutting, the workpiece is pressed against the base 18 for cutting.

[0017] The mounting part 16 connected below the motor case 15 is provided with a plurality of intake ports 15a as air inlets, while the main body part 12h connected above the motor case 15 is provided with a plurality of exhaust ports 15b as air outlets. Therefore, the air taken in from the intake ports 15a as cooling air is discharged to the outside from the exhaust ports 15b through the inside of the motor case 15.

[0018] The main housing 12 consists of a hard resin part 12a and a soft resin part 12b, which are formed by integral molding. The hard resin part 12a is made of a synthetic resin such as polycarbonate. On the other hand, the soft resin part 12b is mainly placed on the surface of areas that require gripping force, such as the handle 14, and areas where there is a concern that the main housing 12 or the object it comes into contact with may be damaged by contact with materials or the ground, and is made of an elastomer material such as. Furthermore, as shown in Figure 3, the main housing 12 has two housing halves, a right main housing 12c and a left main housing 12d, and the main housing 12 is assembled by joining these two housing halves together. As shown in Figure 9, the main body part 12h of the main housing 12 and the inner wall of the motor case 15 are provided with support parts 12e, 12f, and 12i that protrude inward (towards the transmission mechanism housing 23). The support portion 12e, which protrudes from the inner surface of the main body portion 12h, is located outside the transmission mechanism housing 23, which is located radially outside the gear 29 housed in the transmission mechanism housing portion 23a. The support portion 12e abuts against the outer surface of the transmission mechanism housing 23 to position the transmission mechanism housing 23 relative to the main housing 12. The transmission mechanism housing 23, located radially outside the gear 29, is partially circular to match the outer shape of the gear 29. The support portion 12e, which consists of multiple ribs spaced apart in the front-rear and upper-lower directions, supports this portion, thereby optimally positioning the transmission mechanism housing 23. Air passages are formed between the ribs in the support portion 12e. In addition, a partition wall 12g is provided on the inner surface of the main housing 12. The partition wall 12g is a wall (rib) that supports the transmission mechanism housing 23. The partition wall 12g also functions as a wall that divides the internal space of the main housing 12 in the front-rear direction. Although Figure 9 only shows the support sections 12e, 12f, 12i, and partition wall 12g of the left main housing 12d, the right main housing 12c also has similar support sections 12e, 12f, 12i, and partition wall 12g.

[0019] Furthermore, as shown in Figure 2, the work machine 10 is provided with a metal transmission mechanism housing 23 that houses a transmission mechanism 40 that transmits power from the motor 11 shown in Figure 4 to the plunger 35. The transmission mechanism housing 23 is a single part formed from a metal such as an aluminum alloy. The transmission mechanism housing 23 comprises a transmission mechanism housing portion 23a that houses the transmission mechanism 40, and a stator support portion (fitted portion) 23b that is located on the outer circumference of the stator 11a and supports the stator 11a. In detail, the transmission mechanism housing portion 23a and the stator support portion 23b are integrally molded, and the stator support portion 23b is a support portion that extends from the transmission mechanism housing portion 23a toward the stator 11a side (downward side). Therefore, the transmission mechanism housing 23 is a housing with a substantially L-shape. The transmission mechanism housing 23a, which houses the transmission mechanism 40, is located within the main body 12h of the main housing 12, and the stator support 23b, which supports the stator 11a, is located within the motor case 15 of the main housing 12. As will be described in detail later, the stator support 23b is also configured to perform axial positioning with respect to the rotor 11d and the rotation shaft 11e. Therefore, the stator support 23b can be said to be both a motor support and a rotor support. In addition, a trigger switch 20a that operates in conjunction with the trigger 20 is provided at the upper end of the handle 14, and a controller (power supply unit) 21 that controls the drive of the motor 11 is provided in the mounting unit 16 connected to the lower part of the motor case 15. The trigger switch 20a and the controller 21 are electrically connected by wiring 22 that is routed through the inside of the handle 14 and the mounting unit 16, respectively.

[0020] In the work machine 10, as shown in Figure 2, the transmission mechanism housing portion 23a of the transmission mechanism housing 23 is located within the main body portion 12h, and the stator support portion 23b of the transmission mechanism housing 23 is located within the motor case 15 connected to the lower part of the main body portion 12h. Meanwhile, electrical components (powered parts) such as wiring 22, controller 21, and stator 11a are arranged within the handle 14, mounting portion 16, and motor case 15. Therefore, the transmission mechanism housing region 24, where the transmission mechanism housing 23 is located, and the electrical component housing region 25, where the controller 21 and stator 11a are located, overlap within the motor case 15. In other words, the transmission mechanism housing 23 covers the powered parts, including at least one of the stator 11a or controller 21 (in the work machine 10 of this embodiment, the stator 11a is covered by the stator support portion 23b of the transmission mechanism housing 23). Therefore, at least a portion of the stator 11a is covered by the transmission mechanism housing 23 and also by the main housing 12. Furthermore, the transmission mechanism housing 23 is entirely covered by the main housing 12. Note that the overlap between a portion of the transmission mechanism housing area 24 and a portion of the electrical component housing area 25 within the motor case 15 helps to prevent the work machine 10 from becoming larger. In this embodiment, the entire transmission mechanism housing 23 is covered by the main housing 12, but it is also possible to configure the transmission mechanism housing 23 so that a portion is covered by the main housing 12 and the other portion is housed in a separate housing, or for the entire transmission mechanism housing 23 to be housed in a separate housing that is a separate part (separate component) from the main housing 12. Note that in this embodiment, since the entire transmission mechanism housing 23 is covered by the main housing 12, the number of parts can be reduced.

[0021] As shown in Figure 4, the stator support portion 23b of the transmission mechanism housing 23 is provided with a stator 11a, which includes a stator core 11b around which a stator coil 11c is wound, and an insulator 11h made of an insulating material. A sensor board 21a equipped 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). Therefore, the sensor board 21a is configured to be held by the transmission mechanism housing 23 (stator support portion 23b). The rotating shaft 11e, which is configured to rotate integrally with the rotor 11d, is provided with a pinion (not shown) at its upper end, and this pinion meshes with a gear 29. The upper part of the rotating shaft 11e is held by an upper bearing 27, and the lower part is held by a lower bearing 28. In other words, the lower bearing 28 provided on the rotating shaft 11e is supported by a resin bearing holder 26. Furthermore, a centrifugal fan (fan) 51 is provided on the rotating shaft 11e of the motor 11 to supply air in the radial direction of the rotating shaft 11e. A fan guide 50 is provided on the stator 11a side of the centrifugal fan (fan) 51 to guide the airflow.

[0022] The gear 29 that meshes with the motor 11's rotating shaft 11e rotates around a rotating shaft 30 supported by the transmission mechanism housing 23a. The gear 29 is equipped with a crank 34 that rotates together with the gear 29, and the crank 34 rotates eccentrically with the rotation of the gear 29. The crank 34 is also equipped with a plunger (output part) 35, and when the crank 34 rotates eccentrically, the plunger 35 reciprocates. Furthermore, the reciprocating motion of the plunger 35 causes the blade 17 attached to the blade mounting part 19 at the tip of the plunger 35 to reciprocate. The reciprocating motion of the plunger 35 is guided by two rollers 36 provided within the main body 12h.

[0023] Furthermore, 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 set to operate with a phase difference of 180° from each other. For example, when the plunger 35 moves forward, the counterweight 37 moves backward, and when the plunger 35 moves backward, the counterweight 37 moves forward. In this way, the counterweight 37 cancels out the vibrations caused by the movement of the plunger 35.

[0024] Furthermore, the gear 29 has multiple steel balls 31 arranged on its underside, and these steel balls 31 are supported by a strut washer 32. In addition, a damper 33 is provided at the bottom of the strut washer 32. Therefore, although the gear 29 tilts when subjected to a reaction force, the damper 33 is designed to absorb that reaction force, thereby suppressing the tilting of the gear 29.

[0025] Furthermore, the rotating shaft 11e of the motor 11 and the gear 29 are meshed by a helical gear, and when the load on the plunger 35 increases rapidly, the rotating shaft 11e is configured to be pulled upward. In the work machine 10, the lower end of the rotating shaft 11e of the motor 11 is supported by a bearing holder 26 via a lower bearing 28, but under high load, the rotating shaft 11e is pulled upward, so the bearing holder 26 is biased downward and does not come off, and the support structure of the motor 11 is designed not to be easily disassembled.

[0026] Furthermore, the battery pack 13 contains multiple battery cells 13a, and power is supplied from the battery pack 13 to the motor 11. When the operator operates the trigger 20 on the handle 14, the trigger switch 20a built into the handle 14 is activated, and power for the cutting operation is output from the controller 21, supplying motor current to the motor 11. As a result, the motor 11 operates, and the crank 34 rotates eccentrically due to the rotation of the gear 29, causing the plunger 35 to reciprocate (move back and forth). Consequently, the blade 17 attached to the tip of the plunger 35 reciprocates (move back and forth), and cutting is performed. The motor 11 is a brushless motor, and the controller 21 is equipped with multiple switching elements (inverter circuits) for controlling the motor 11, and a control unit (microcontroller) for controlling the switching elements on and off.

[0027] Next, the detailed structure of the transmission mechanism housing 23, which is assembled to the work machine 10, will be described. As shown in Figures 5 and 6, the transmission mechanism housing 23 is a metal housing in which a transmission mechanism housing 23a located at the top and a stator support 23b located at the bottom are integrally formed. It consists of a box-shaped (container-shaped) transmission mechanism housing 23a and an annular (cylindrical) stator support 23b. In other words, the transmission mechanism housing 23a and the stator support 23b are each part of a single component (transmission mechanism housing 23) and are configured to be inseparable. The stator support 23b extends downward from the transmission mechanism housing 23a, and the transmission mechanism 40 is housed in the transmission mechanism housing 23a, while the stator 11a is supported in the stator support 23b. As shown in Figure 5, the side wall 23c of the transmission mechanism housing 23a is provided with a plurality of screw bosses 23d, and the transmission mechanism housing 23 is screw-fixed to these screw bosses 23d with the upper cover 49 (see Figure 7), which will be described later. In addition, a plurality of ribs 23c1 are formed on the side wall 23c. Furthermore, as shown in Figure 6, the bottom of the transmission mechanism housing 23a is provided with 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. The bearing portion 23j has a circular motor shaft opening 23g in which the rotating shaft 11e is arranged, and the bearing portion 23k has a circular transmission mechanism shaft opening 23h in which the rotating shaft 30 is arranged. The bearing sections 23j and 23k are provided with multiple ribs 23e and 23f extending in the radial direction of their respective rotating shafts 11e and 30, respectively, ensuring with high precision that the center positions of the circular motor shaft opening 23g and the circular transmission mechanism shaft opening 23h do not shift.

[0028] Next, the structure of the transmission mechanism 40 in the work machine 10 will be described in detail with reference to Figure 7. The transmission mechanism housing 23a of the transmission mechanism housing 23 is provided with at least a gear 29 and an eccentrically rotating crank 34 attached to the gear 29 as the transmission mechanism 40. The crank 34 is also provided with a plunger 35 as an output part via a sleeve 41. Specifically, the crank 34 engages 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 mounting 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 mounting portion 19, which is covered by a dust guard 38. The plunger 35 reciprocates with its tip guided by a roller 36. The O-ring 39 is held in place by fitting into a groove formed in the front end portion of the transmission mechanism housing 23.

[0029] Multiple steel balls 31 are arranged in a circular pattern on the underside of the gear 29. These steel balls 31 are supported by a strut washer 32 and are in contact with the underside of the gear 29. Furthermore, a damper 33 is provided below the strut washer 32. This allows the damper 33 to absorb the reaction force received by the gear 29, thereby suppressing tilting of the gear 29.

[0030] The plunger 35 is supported by guide members 42 positioned on both the left and right sides, so as to be able to reciprocate on guide members 42 to which it is attached via bolts 35b. Grooves are formed on the inside of the guide members 42, and the sides of the plunger 35 fit into these grooves. In this way, the plunger 35 is supported by the left and right guide members 42 so as to be able to reciprocate (move back and forth).

[0031] Furthermore, a counterweight 37 is provided at the upper end of the crank 34, which operates 180° out of phase with the plunger 35. That is, when the crank 34 rotates eccentrically, the counterweight 37 also reciprocates, thereby canceling out the vibrations caused by the movement of the plunger 35. The counterweight 37 is supported so as to be able to reciprocate by metal guides 46 located on both the left and right sides, and each guide 46 is supported by a rubber damper 47. As a result, vibrations during the movement of the counterweight 37 are absorbed by the damper 47. In addition, the left and right guides 46 are each supported by spacers 43, and a metal plate 44 that presses down on the guide member 42 of the plunger 35 is tightened and fixed from above by bolts 44a. The counterweight 37 is supported by the guides 46 via a plurality of steel balls 45 located in grooves 37b formed on the side surface of the counterweight 37. Specifically, multiple steel balls 45 are sandwiched between the counterweight 37 and guides 46 provided on both the left and right sides of the counterweight 37, and are supported by the guides 46 so as to be able to reciprocate (move back and forth) via these steel balls 45. In addition, multiple steel balls 45 are also arranged in the holes 37a 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 by multiple bolts 49a via a frame-shaped sealing material 48, the multiple 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.

[0032] As described above, in the work machine 10, the stator 11a is directly supported by the metal transmission mechanism housing 23, so that the positional accuracy of the stator 11a relative to the transmission mechanism housing 23 can be ensured. As a result, high assembly precision is not required when assembling the housing, and assembly can be easily performed.

[0033] Furthermore, since the transmission mechanism housing section 23a, which houses the transmission mechanism 40, and the stator support section 23b, which supports the stator 11a, are integrally molded, screws are not required to assemble these two housings. Consequently, the number of screw bosses can also be reduced, thus preventing the work machine 10 from becoming larger due to the presence of screw bosses. Moreover, since the number of screws can be reduced, the cost of the work machine 10 can be reduced.

[0034] The stator support portion 23b includes a plurality of extending portions 23b1 extending downward (towards the stator 11a) from the transmission mechanism housing portion 23a, a connecting portion 23b2 that connects two extending portions 23b1 to each other, an opening 23b3 surrounded by the extending portions 23b1 and the connecting portions 23b2, ribs 23b4 provided on the outer portion of the extending portions 23b1, and a fitting portion 23b5 provided on the inner side of the extending portions 23b1. A total of four extending portions 23b1 are formed on the transmission mechanism housing 23, two on the left side and two on the right side. The connecting portion 23b2 is connected to the lower ends of two extending portions 23b1 that are spaced apart in the front-rear direction and located on the left or right side. The connecting portion 23b2 is formed in a substantially arc shape (partially annular). The opening 23b3 is a space that connects the inside and outside of the stator support portion 23b. The opening 23b3 serves as a passage for air supplied from the centrifugal fan 51. The opening 23b3 is also an opening (space) that extends along a direction parallel to the rotation axis 11e, surrounded by the extended portion 23b1 and the connecting portion 23b2. The opening 23b3 also functions as a thinning portion to reduce the weight of the transmission mechanism housing 23. The rib 23b4 is the part that engages with the main housing 12. The rib 23b4 also functions as a reinforcing rib to prevent the extended portion 23b1 from bending in the left-right direction. The fitted portion 23b5 is the part of the extended portion 23b1 that is recessed outward and is the part that fits (engages) directly or indirectly with the stator 11a. The recessed fitted portion 23b5 creates a step at the upper end of the fitted portion 23b5, and this part becomes the abutment portion 23b6 against which the fan guide 50, described later, strikes. The abutment portion 23b6 is provided on each of the four extending portions 23b1.

[0035] Next, the assembly of the stator 11a and rotor 11d (rotating shaft portion) from the transmission mechanism housing 23 to the stator support portion 23b will be explained using Figures 8 to 10. First, the rotor 11d, the rotating shaft 11e, the centrifugal fan 51, bearing 27, and bearing 28 are unitized (as the rotating shaft portion). Next, the unitized bearing 27 is attached to the transmission mechanism housing 23. In this way, the rotor 11d, the rotating shaft 11e, and the centrifugal fan 51 are held in the transmission mechanism housing 23. Next, with the fan guide (positioning member) 50 fitted to the outer circumference of the stator 11a, the fan guide 50 is fitted into the mating portion 23b5 from the lower side of the stator support portion 23b. In other words, the stator 11a is inserted in the direction along the rotating shaft 11e of the motor 11 (vertical direction) and mated with the stator support portion 23b (matting portion 23b5). Specifically, the four support portions 50a of the ring-shaped fan guide 50, which guides the airflow generated by the centrifugal fan 51, are press-fitted into the inside of the stator support portion 23b (fitted portion 23b5), and the stator 11a is fitted into the fan guide 50 (support portions 50a) fitted into the stator support 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 to facilitate fitting into the stator support portion 23b. In addition, a notch 50b for airflow is formed in a part of the ring-shaped fan guide 50. As shown in Figure 10, the fan guide 50 inserted (fitted) into the stator support portion 23b (fitted portion 23b5) comes into contact with the abutment portion 23b6 of the stator support portion 23b, thereby restricting its upward movement.

[0036] After fitting the support portion 50a of the fan guide 50 and the stator 11a into the inside of the stator support portion 23b, the resin bearing holder 26 is fitted into the inside of 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 to facilitate fitting into the stator support portion 23b (fitted portion 23b5). As described above, the stator support portion 23b is provided so as to overlap the support portion 50a of the fan guide 50 and the support portion 26a 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, it becomes a metal-to-metal fitting, which may make it difficult to insert the stator core 11b into the stator support portion 23b by hand. The support portion 50a of the fan guide 50 and the support portion 26a of the bearing holder 26 are both made of resin, and are easier to crush and form compared to the transmission mechanism housing 23 and the stator core 11b. In this embodiment, a resin positioning member (fan guide 50) is interposed between the stator support portion 23b (transmission mechanism housing 23) and the stator 11a, so that the positioning member can be easily pressed in by crushing it, making it easy to insert the stator core 11b into the stator support portion 23b by hand. Furthermore, since chamfered portions 50c and 26b are formed, the fitting with the stator support portion 23b can be performed smoothly. Also in this embodiment, an electrically insulating (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 11a and the transmission mechanism housing 23. This allows for electrical isolation between the stator 11a, which has energized parts, and the metal transmission mechanism housing 23, while the stator 11a is supported by the transmission mechanism housing 23.Furthermore, by fitting (press-fitting) the stator 11a with the stator support portion 23b, the extended portion 23b1 of the stator support portion 23b is biased in the radial direction (direction along the plane extending in the front, back, left, and right directions) around the rotation axis 11e, and therefore tends to deform in this direction. However, since the connecting portion 23b2 connects the extended portions 23b1 to each other, it suppresses the relative separation of the extended portions 23b1 to each other, thereby suppressing the separation of the extended portions 23b1 (fitted portion 23b5) from the stator 11a.

[0037] After fitting the stator 11a to the stator support portion 23b, the bearing holder 26 is fitted into the inside of the stator support portion 23b from below, causing the upper end of the support portion 26a of the bearing holder 26 to abut against the stator core 11b (see Figure 10). This positions the bearing holder 26, and as a result, positions the stator 11a on the stator support portion 23b. In addition, the bearing 28 is fitted into the bearing holder 26 by this fitting, thereby positioning the rotating shaft 11e and the bearing 28 in the axial direction. That is, the bearing 28 is held by the bearing holder 26, which is held by the stator support portion 23b, and the rotating shaft 11e is positioned in the axial and radial directions.

[0038] As described above, in the work machine 10, a positioning member is provided on the outer circumference of the stator 11a to position 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. Furthermore, in the work machine 10, a fan guide 50, which 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. In other words, the stator 11a is supported by the stator support portion 23b of the transmission mechanism housing 23 without the use of fasteners such as screws. To put it another way, the stator 11a is supported by fitting into the stator support portion 23b of the transmission mechanism housing 23. By using the fan guide 50 and bearing holder 26 as positioning members for the stator 11a, parts can be shared, which can reduce the cost of the work machine 10. In addition, there is no need to provide an anti-rotation structure for the stator 11a or the transmission mechanism housing 23, which simplifies the structure around the motor. The upper bearing 27 is fixed in place by a bearing lock 27a, and the lower bearing 28 is fixed in place by a bearing lock 28a. The stator 11a and the rotating shaft portion (rotor 11d, rotating shaft 11e, etc.) are held in place by the transmission mechanism housing 23 with a certain degree of holding force in the axial direction (up and down direction) by press-fitting and bearing locks, but they will fall out of the stator support portion 23b if strongly biased downwards. In other words, at this stage (before being housed in the main housing 12), the stator 11a and the rotating shaft portion (rotor 11d, rotating shaft 11e, etc.) will come out of the transmission mechanism housing 23 if strongly pulled downwards. In this invention, the axial movement of the stator 11a and the rotating shaft portion (rotor 11d, rotating shaft 11e, etc.) is restricted by the main housing 12 as described below.

[0039] After fitting the bearing holder 26, when the right main housing 12c and the left main housing 12d shown in Figure 3 are assembled, the support portion 12f provided on the inner wall of the main housing 12 fits into the lower side of the bearing holder 26, as shown in Figure 10. That is, the support portion 12f of the main housing 12 abuts against the lower end of the bearing holder 26. As a result, the bearing holder 26 cannot be removed downwards (downward movement is restricted). Here, the support portion 12f of the main housing 12 is a restricting portion that restricts the movement of the stator 11a in the direction away from the transmission mechanism 40 (downward direction). Also, the lower end of the stator support portion 23b abuts against 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. The bearing holder 26 supports the bearing 28 that supports the rotating shaft 11e in the axial direction, and also supports the stator 11a (stator core 11b) in the axial direction from bottom to top. Therefore, if 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, the position fixing of the stator 11a and rotor 11d is completed. To put it another way, the screws used to assemble the right main housing 12c and the left main housing 12d fix the stator 11a to the transmission mechanism housing 23.

[0040] Next, the mechanism for preventing rotation of the stator 11a in the work machine 10 will be described. Figure 11 is a view from below of a cross-section of the area around the stator support portion 23b in the front-rear and left-right directions, at a position below the support portion 12f. As shown in Figure 11, the outer circumference of the stator 11a has four outwardly protruding protrusions 11f formed at its circumferential direction. The support portion 50a of the fan guide 50 fits over each of these four protrusions 11f and engages in the clockwise and counterclockwise directions in Figure 11 (rotation prevention portion S2). Furthermore, the stator support portion 23b of the transmission mechanism housing 23 fits over each of the four support portions 50a and engages in the clockwise and counterclockwise directions in Figure 11. 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. Furthermore, the ribs 23b4 provided on the outside of the extended portion 23b1 engage with the support portion 12f (or its recess), thereby preventing the transmission mechanism housing 23 from rotating relative to the main housing 12. Ribs 23b4 are provided on each of the four extended portions 23b1, and engage with the support portion 12f at a total of four locations, two on each side.

[0041] Furthermore, the fan guide 50 is provided with a projection 50d, and the stator 11a is provided with a recess 11g on its outer circumference. The projection 50d fits into the recess 11g, preventing the stator 11a from rotating relative to the fan guide 50 and preventing incorrect assembly of the stator 11a to the fan guide 50 (anti-rotation part S1).

[0042] Next, the mechanism for preventing rotation of the bearing holder 26 in the work machine 10 will be described. Figure 12 is a view from below of a cross-section in the front-rear, left-right, and right-hand directions at a position just above the bearing 28. As shown in Figure 12, chamfered portions 26b are formed on each of the four support portions 26a of the bearing holder 26. On the other hand, projections 23b7 are formed on four locations (fitted portions 23b5) of the stator support portion 23b of the transmission mechanism housing 23 that correspond to the circumferential support portions 26a. The bearing holder 26 can be prevented from rotating by engaging the support portions 26a of the bearing holder 26 and the projections 23b7 of the stator support portion 23b at four locations (anti-rotation portions S3). More specifically, the front left and rear right projections 23b7 restrict the clockwise rotation of the bearing holder 26 in Figure 12 relative to the rotation axis 11e, and the front right and rear left projections 23b7 restrict the counterclockwise rotation of the bearing holder 26 in Figure 12 relative to the rotation axis 11e.

[0043] Next, the cooling air passage in the work machine 10 will be described. As shown in Figure 13, the rotation of the centrifugal fan 51, which is provided on the rotating shaft 11e of the motor 11, generates negative pressure below the centrifugal fan 51, drawing air (outside air) into the work machine 10. Specifically, the air is taken in from the intake port 15a of the main housing 12 (air passage 52), passes mainly inside the stator 11a, and reaches the centrifugal fan 51. The air that reaches the centrifugal fan 51 is then blown radially outward by the centrifugal fan 51. The air blown radially outward by the centrifugal fan 51 is guided in direction by hitting the inner wall of the main housing 12. Here, a support part 12i and a fan guide 50 are provided below the centrifugal fan 51, so that the air hitting the inner wall of the main housing 12 does not flow downward. Therefore, the air hitting the inner wall of the main housing 12 flows mainly upward. The air blown upward from the centrifugal fan 51 passes through the side of the transmission mechanism housing 23 and then exits to the outside through the exhaust port 15b of the main housing 12 (air passage 54). The space on the left and right outer sides of the transmission mechanism housing 23a is partitioned in the front-to-back direction by a partition wall 12g, so that the air blown from the centrifugal fan 51 does not flow forward. In addition, a notch 50b is formed in the fan guide 50, so that air passing over the outer circumference of the stator 11a can be drawn into the centrifugal fan 51 through the notch 50b (air passage 53).

[0044] Here, in order to allow air to flow from the centrifugal fan 51, which is covered by the stator support portion 23b, to the outside of the transmission mechanism housing 23, an air passage is necessary. Therefore, in this embodiment, an opening 23b3 is provided in the stator support portion 23b, which is an opening that penetrates radially (left and right). For example, if the stator support portion 23b is a cylindrical shape without holes, it becomes difficult to allow air to flow to the outside of the transmission mechanism housing 23, but in this embodiment, an air passage can be created by the opening 23b3. In particular, since the opening 23b3 is located radially outside the centrifugal fan 51, the air from the centrifugal fan 51 is immediately sent to the outside of the transmission mechanism housing 23, resulting in a smooth airflow. Alternatively, the air from the centrifugal fan 51 may first pass inside 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 conceivable to provide a through-hole above the centrifugal fan 51 to serve as an air passage. However, since the transmission mechanism housing 23a, which is filled with lubricant (grease), is located directly above the stator support 23b, it is necessary to slightly offset the position of the stator support 23b (stator 11a) downwards, which may lead to an increase in the size of the main body. Therefore, the present invention, in which the opening 23b3 is located radially outward of the centrifugal fan 51, is more preferable for a work machine.

[0045] This allows the stator 11a and the transmission mechanism housing 23 to be cooled. The intake port 15a and exhaust port 15b are provided on the right main housing 12c and the left main housing 12d, respectively, so that cooling air can be supplied to both the left and right sides of the stator 11a and the transmission mechanism housing 23. In addition, multiple ribs 23c1 are formed on the side wall 23c of the transmission mechanism housing 23, which function as heat dissipation fins, and air flows outside the ribs 23c1, so the transmission mechanism housing 23 can be cooled effectively.

[0046] The present invention is not limited to the above embodiments and can be modified in various ways without departing from its essence. For example, in the above embodiments, the case in which the stator support portion 23b is located below the transmission mechanism housing 23 was described, but the stator support portion 23b (stator 11a) may be configured to be located behind the transmission mechanism housing 23. Also, although the form of a reciprocating saw was described as the work machine, the present invention can be applied to work machines that use a metal transmission mechanism housing, such as grinders and jigsaws. Furthermore, the present invention can also be applied to systems that use an AC power source instead of a battery pack (battery), that is, systems that have a power cord. Also, although there are four extended portions 23b1, there may be more or fewer. Also, although the main housing 12 is composed of a hard resin portion 12a and a soft resin portion 12b, it is also possible to compose it using only a hard resin portion. [Explanation of Symbols]

[0047] 10...Work implement, 11...Motor, 11a...Stator (electrical part), 11b...Stator core, 11c...Stator coil, 11d...Rotor, 11e...Rotating shaft, 11f...Convex part, 11g...Concave part, 12...Main housing, 12a...Hard resin part, 12b...Soft resin part, 12c...Right main housing, 12d...Left main housing, 12e...Support part, 12f...Support part (regulating part), 12g...Bulkhead, 12h...Main body, 12i...Support part, 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 (powered part), 21a...Sensor board, 22...Wiring, 23...Transmission mechanism housing, 23a...Transmission mechanism housing part, 23b...Stator support part (fitted part), 23c...Side wall, 23d...Screw boss, 23e, 23f...Ribs, 23g...Opening for motor shaft, 23h...Opening for transmission mechanism shaft, 23b7...Protrusion, 23j, 23k...Bearings 24...Transmission mechanism housing area, 25...Electrical 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...Strass 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…upper cover, 49a…bolt, 50…fan guide (positioning member), 50a…support part, 50b…notch, 50c…chamfered part, 50d…projection, 51…centrifugal fan (fan), 52,53,54…air passage, S1,S2,S3…anti-rotation part

Claims

1. A motor having a stator and a rotor, Driven by the aforementioned motor, the output unit to which a cutting tool can be attached, The output unit includes a transmission mechanism for transmitting power from the motor, A resin positioning member made of resin that contacts the side surface of the stator, A metal transmission mechanism housing comprising a transmission mechanism housing portion for housing the transmission mechanism, and a stator support portion located on the outer circumference of the stator and supporting the stator via the positioning member, It comprises a resin main housing that houses the stator support portion and the stator supported by the stator support portion, and has a handle portion that can be gripped by an operator, By gripping the handle portion and pressing the tip tool against the workpiece, machining can be performed. The stator is held in place by press-fitting via the positioning member in the work machine.

2. A motor having a stator and a rotor that rotates about a first axis, A resin main housing that houses the motor and is equipped with a handle and a restricting part that can be gripped by an operator, Driven by the aforementioned motor, the output unit to which a cutting tool can be attached, The output unit includes a transmission mechanism for transmitting power from the motor, A metal transmission mechanism housing that houses the transmission mechanism and has a fitting portion, A work machine having, By gripping the handle portion and pressing the tip tool against the workpiece, machining can be performed. The regulating portion extends from the inner surface of the main housing and, when viewed in the first direction, at least a portion of it overlaps with the stator. A work machine in which the stator is fitted with the fitting portion in a direction toward one side of the first direction, and movement toward the other side of the first direction toward the other side toward the transmission mechanism housing is restricted by the restricting portion.

3. The work machine according to claim 1, wherein the main housing includes a restricting portion that restricts the stator from moving away from the transmission mechanism.

4. The work machine according to claim 1, wherein the stator support portion extends from the transmission mechanism housing portion toward the stator side.

5. It has a controller that controls the drive of the motor, The work machine according to claim 1 or 2, wherein the transmission mechanism housing covers an energized portion including at least one of the stator or the controller.

6. The work machine according to claim 1 or 2, wherein at least a portion of the stator is covered by the transmission mechanism housing and is also covered by the main housing.

7. The work machine according to claim 6, wherein part or all of the transmission mechanism housing is covered by the main housing.

8. A positioning member for positioning the stator is provided on the outer circumference of the stator. The work machine according to claim 2, wherein the stator is supported by the transmission mechanism housing via the positioning member.

9. A fan is provided on the rotating shaft of the aforementioned motor. The work machine according to claim 1 or 8, wherein the positioning member has a fan guide that guides the airflow generated by the fan.

10. A bearing is provided on the rotating shaft of the motor. The work machine according to claim 1 or 8, wherein the positioning member has a bearing holder for holding the bearing.

11. The work machine according to claim 8, wherein the positioning member is a resin member.

12. The work machine according to claim 1 or 2, wherein the stator is supported in the transmission mechanism housing via an insulating member.

13. The work machine according to claim 1, wherein the stator support portion is provided with an opening that penetrates the stator in the radial direction.

14. It has a fan that is rotated by the aforementioned motor, The work machine according to claim 13, wherein the opening is configured to serve as a passage for air when the fan rotates.

15. The work machine according to claim 1 or 2, wherein the stator, covered by the transmission mechanism housing, is configured to be housed in the main housing.

16. The work machine according to claim 1 or 8, wherein the positioning member includes a first support component that abuts against the side surface of the stator on one axial side of the rotor, and a second support component, which is a separate component from the first support component and abuts against the side surface of the stator on the other axial side of the rotor.

17. The rotor rotates about the first direction as its axis, The work machine according to claim 1, wherein the positioning member restricts the rotation of the stator about the first direction relative to the stator support.

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