WO2021111990A1

WO2021111990A1 - Air blower

Info

Publication number: WO2021111990A1
Application number: PCT/JP2020/044111
Authority: WO
Inventors: 文年沼田
Original assignee: 株式会社マキタ
Priority date: 2019-12-06
Filing date: 2020-11-26
Publication date: 2021-06-10
Also published as: JP2021092162A

Abstract

According to the present invention, an air duster 1 comprises a motor 4, a compression mechanism 6, a tubular part 21, and a support body 5. The motor 4, which is a brushless motor, comprises a stator 1, a rotor 45, and a motor shaft 471 that can rotate around a rotary shaft A1 integrally with the rotor 45. The compression mechanism 6 is configured to be driven by the motor 4 to generate compressed air. The tubular part 21 is made of metal and accommodates at least the motor 4. The support body 5 is made of synthetic resin and is disposed between the stator 41 and the tubular part 21 in the radial direction of the stator 41. The stator 41 is supported by the tubular part 21 via the support body 5.

Description

Blower

The present disclosure relates to a blower, and more particularly to an electric blower capable of discharging compressed air.

A blower that can blow off dust and the like by discharging compressed air from a nozzle is known. Such a blower is generally called an air duster. For example, Japanese Patent Application Laid-Open No. 2011-117442 discloses an air duster configured to generate compressed air by a five-stage centrifugal fan rotated by a motor and inject the generated compressed air. The motor is housed in a tubular housing and fixed to the housing by an appropriate rib structure.

In an air duster that uses compressed air as described above, it is conceivable to drive the motor at a higher speed in order to increase the wind power. When the speed of the motor is increased, further improvement is desired in the housing for accommodating the motor and the support structure of the motor.

It is an object of the present disclosure to provide improvements in the housing of a blower capable of discharging compressed air and the support structure of a motor in view of such a situation.

According to one aspect of the present disclosure, an electric blower configured to discharge compressed air from a discharge port is provided. The blower includes a motor, a compression mechanism, a housing, and a support. The motor is a brushless motor and includes a stator, a rotor, and an output shaft that is integrally rotatable about a first axis with the rotor. The compression mechanism is driven by a motor and is configured to generate compressed air. The housing is made of metal and has a tubular shape. The housing houses at least the motor. The support is made of synthetic resin. The support is arranged between the stator and the housing in the radial direction of the stator. The stator is supported by the housing via a support.

According to this aspect, by making the housing for accommodating the motor made of metal, it is possible to maintain good durability of the housing even when the motor is driven at high speed. In addition, by arranging a synthetic resin support between the stator and the metal housing, a sufficient distance is secured between the conductor of the stator and the metal housing, and the housing affects the motor. The possibility of giving can be reduced.

In one aspect of the present disclosure, at least one of the housing and the support may include a first positioning portion configured to position the housing and the support in a circumferential direction around the first axis. According to this aspect, the support can be easily assembled to the housing.

In one aspect of the present disclosure, at least one of the support and the stator may include a second positioning portion configured to position the support and the stator in the circumferential direction around the first axis. According to this aspect, the support can be easily assembled to the stator.

In one aspect of the present disclosure, the support may be configured to form a ventilation path between the support and the stator. According to this aspect, the motor can be effectively cooled by the air passing through the ventilation passage formed on the radial outer side of the stator.

In one aspect of the present disclosure, the support may be a tubular body. The support may include at least one first wall and at least one second wall. At least one first wall portion may abut on the outer peripheral surface of the stator. At least one second wall may project radially outward of the support than at least one first wall. The ventilation passage may be formed by a gap formed between the outer peripheral surface of the stator and the inner peripheral surface of at least one second wall portion.

In one aspect of the present disclosure, the housing may include at least one protrusion. At least one protrusion may project radially inwardly of the housing and abut on the outer peripheral surface of the support to support the support radially substantially immovably. At least one protrusion is arranged adjacent to at least one shoulder portion between at least one first wall portion and at least one second wall portion of the support in the circumferential direction around the first axis. May be good.

In one aspect of the present disclosure, at least one protrusion may have a protrusion that abuts the support in the axial direction of the output shaft.

In one aspect of the present disclosure, the support may be composed of a plurality of members. In this embodiment, the support may be formed by connecting a plurality of members in the circumferential direction around the axis. The term "connected" as used herein may include not only inseparably fixing a plurality of members from each other but also maintaining them in contact with each other. According to this aspect, assembling the support to the stator becomes easier.

In one aspect of the present disclosure, the blower further comprises a bearing that rotatably supports one end of the output shaft and a metal cover that holds the bearing and is configured to cover the opening at one end of the housing. You may. According to this aspect, a rational configuration is realized in which the cover of the housing also serves as the holding member of the bearing.

In one aspect of the present disclosure, the cover may have an abutting portion configured to abut the support and restrict the support from moving toward the cover in the axial direction of the output shaft. According to this aspect, a rational configuration is realized in which the housing cover can regulate the movement of the support.

In one aspect of the present disclosure, the contact portion may be configured as a protrusion protruding toward the stator side in the axial direction of the output shaft. According to this aspect, the possibility that the cover affects the motor can be reduced by making the portion of the metal cover close to the motor as small as possible.

In one aspect of the present disclosure, the compression mechanism may include a plurality of centrifugal fans arranged coaxially with the output shaft in multiple stages and configured to rotate about an axis as the motor is driven. In other words, the blower may be configured as a multi-stage centrifugal blower. According to this aspect, the wind force of the discharged compressed air can be efficiently increased according to the setting of the specifications of the plurality of fans.

In one aspect of the present disclosure, the housing may house a compression mechanism. According to this aspect, the metal tubular housing accommodates both the motor and the compression mechanism, so that air leakage from the housing can be suppressed. As a result, it is possible to suppress a decrease in pressure inside the housing.

It is a left side view of the air duster. It is sectional drawing of the air duster. It is a partial rear view of the air duster. It is a part of the cross-sectional view taken along the line IV-IV of FIG. It is a part of the cross-sectional view taken along the line VV of FIG. It is a partially enlarged view of FIG. It is a partially enlarged view of FIG. FIG. 3 is a cross-sectional view taken along the line VIII-VIII of FIG. FIG. 3 is a cross-sectional view taken along the line IX-IX of FIG. It is a perspective view of the support. It is an exploded perspective view of the support. It is a rear view of the support. It is a perspective view of a rear cover.

Hereinafter, the air duster 1 according to the embodiment of the present disclosure will be described with reference to the drawings. The air duster 1 is a kind of blower capable of blowing off dust and the like by discharging compressed air, and is configured as a hand-held electric tool that the user grips and uses.

First, the outline configuration of the air duster 1 will be described.

As shown in FIGS. 1 to 3, the air duster 1 includes a main body housing 2 and a handle housing 3.

The main body housing 2 is a substantially cylindrical hollow body with both ends covered. The air duster 1 is configured as an electric multi-stage blower. A motor 4 and a compression mechanism 6 including a plurality of fans 60 are housed in the main body housing 2. The motor 4 and the fan 60 are arranged coaxially. The rotation shaft A1 of the motor 4 and the fan 60 extends along the shaft of the main body housing 2. The main body housing 2 has a suction port 201 (see FIG. 3) at one end in the axial direction thereof, and a discharge port 203 at the other end in the axial direction thereof.

As shown in FIGS. 1 and 2, the handle housing 3 covers the outer peripheral surface of the main body housing 2 and protrudes from the main body housing 2 in a direction intersecting the rotation axis A1. A portion of the handle housing 3 extending in a direction intersecting the rotation axis A1 constitutes a grip portion 33. A trigger 331 that allows a user to perform a pressing operation (pulling operation) is provided at a base end portion (end portion on the main body housing 2 side) of the grip portion 33. Further, a battery (also referred to as a battery pack) 370 is detachably mounted on the protruding end (tip) of the handle housing 3 via the battery mounting portion 37.

When the trigger 331 is pulled by the user, the motor 4 is driven and air is sucked into the main body housing 2 from the suction port 201. The sucked air is compressed by the compression mechanism 6. The compressed air (hereinafter referred to as compressed air) is discharged from the discharge port 203.

The detailed configuration of the air duster 1 will be described below. In the following, for convenience of explanation, the extending direction of the rotating shaft A1 of the motor 4 (specifically, the motor shaft 471) and the fan 60 (which can also be said to be the axial direction of the main body housing 2) is defined as the front-rear direction of the air duster 1. .. In the front-rear direction, the side where the discharge port 203 is arranged is defined as the front side, and the opposite side (the side where the suction port 201 is arranged) is defined as the rear side. The direction orthogonal to the rotation axis A1 and corresponding to the extending direction of the handle housing 3 is defined as the vertical direction. In the vertical direction, the base end side of the grip portion 33 is defined as the upper side, and the protruding end side of the grip portion 33 (the side to which the battery 370 is attached / detached) is defined as the lower side. The direction orthogonal to the front-back direction and the up-down direction is defined as the left-right direction.

First, the main body housing 2 and the handle housing 3 will be described.

As shown in FIGS. 2 and 3, the main body housing 2 is formed by connecting the tubular portion 21, the front cover 23, and the rear cover 25.

The tubular portion 21 is a substantially cylindrical member and has openings at both ends in the axial direction. The front cover 23 is a tapered funnel-shaped (conical) member formed separately from the tubular portion 21. The front cover 23 is screwed into the front end portion of the tubular portion 21 and covers the opening at the front end of the tubular portion 21. The cylindrical tip of the front cover 23 is referred to as a nozzle 231. The opening of the nozzle 231 constitutes a discharge port 203 in which the air compressed in the main body housing 2 is discharged to the outside of the main body housing 2. The discharge port 203 is arranged on the rotation shaft A1. The rear cover 25 is a member having a circular shape when viewed from the rear, which is formed separately from the tubular portion 21. The rear cover 25 is fixed to the rear end of the tubular portion 21 with screws. The rear cover 25 constitutes a rear wall that covers the opening at the rear end of the tubular portion 21. The rear cover 25 has a plurality of through holes. These through holes function as a suction port 201 for allowing air to flow into the tubular portion 21. In the present embodiment, the tubular portion 21, the front cover 23, and the rear cover 25 are all made of metal (for example, aluminum alloy or magnesium alloy).

The air that has flowed into the main body housing 2 from the suction port 201 flows forward in the main body housing 2, is compressed by the compression mechanism 6, and is discharged from the discharge port 203. Although details are not shown, a cylindrical attachment having an inner diameter larger or smaller than the nozzle diameter can be attached to and detached from the nozzle 231. When the attachment is attached to the nozzle 231 the air discharged from the discharge port 203 passes through the attachment and is discharged from the opening at the tip of the attachment.

As shown in FIGS. 3 to 5, the handle housing 3 is formed by connecting the left shell (left housing portion) 301 and the right shell (right housing portion) 302 formed as separate bodies from each other. There is. The left side shell 301 and the right side shell 302 are connected by screws at a plurality of places with a part of the main body housing 2 (specifically, the tubular portion 21 and the rear side cover 25) sandwiched from the left and right sides. As a result, the main body housing 2 and the handle housing 3 are fixedly connected and integrated. In the present embodiment, the left shell 301 and the right shell 302 are formed substantially symmetrically (including the rotation axis A1 and symmetrical with respect to the plane P extending in the vertical direction) except for the portion connected by the screw. Has been done. In this embodiment, the handle housing 3 (left side shell 301 and right side shell 302) is made of synthetic resin.

Further, as shown in FIGS. 1 and 2, the handle housing 3 includes a cover portion 31, a grip portion 33, and a controller accommodating portion 35. The cover portion 31 is a substantially cylindrical portion of the handle housing 3 that covers the outer peripheral surfaces of a part of the main body housing 2 (specifically, the tubular portion 21 and the rear cover 25). The grip portion 33 is a long tubular portion that connects to the lower end portion of the cover portion 31 and extends downward. The grip portion 33 is gripped by the user when the air duster 1 is in use (during operation). The controller accommodating portion 35 is a rectangular box-shaped portion connected to the lower end portion of the grip portion 32. The controller accommodating portion 35 constitutes the lower end portion of the handle housing 3.

The internal structure of the main body housing 2 will be described below.

As shown in FIG. 6, the main body housing 2 houses the motor 4 and the compression mechanism 6. More specifically, the stator 41 of the motor 4 is arranged in the rear portion of the main body housing 2. The compression mechanism 6 is arranged on the front side of the stator 41. That is, the motor 4 is located between the suction port 201 and the compression mechanism 6 (in the air flow direction, the compression mechanism 6) in the air flow path in the main body housing 2 from the suction port 201 (see FIG. 3) to the discharge port 203. It is located on the upstream side of).

The motor 4 will be described. In this embodiment, an inner rotor type DC brushless motor is adopted as the motor 4. The motor 4 includes a motor main body 40, a motor shaft 471, and a sensor substrate 48. The motor body 40 includes a stator 41 and a rotor 45. Since the motor 4 having such a configuration is well known, it will be briefly described below.

The stator 41 includes a stator core, a coil, and an insulator. A terminal mounting portion (terminal block) 417 for external terminals is provided at the rear end of the stator 41. The terminal mounting portion 417 is arranged on the outer side in the radial direction of the lower end portion of the stator 41. The rotor 45 has a magnet and is arranged inside the stator 41 in the radial direction.

The motor shaft 471 extends in the front-rear direction. The rotor 45 is fixed to the rear end of the motor shaft 471. The motor shaft 471 rotates integrally with the rotor 45 around the rotation shaft A1. The motor shaft 471 extends forward of the stator 41. In the present embodiment, the extension shaft 473 is coaxially connected to the front end portion of the motor shaft 471. The extension shaft 473 rotates integrally with the motor shaft 471 around the rotation shaft A1. Hereinafter, the integrated motor shaft 471 and the extension shaft 473 are collectively referred to as a drive shaft 47. The front and rear ends of the drive shaft 47 are supported by

bearings

477 and 478, respectively, held in the body housing 2. As a result, the drive shaft 47 is rotatably supported around the rotation shaft A1 with respect to the main body housing 2. The support structure of the motor 4 (specifically, the stator 41 and the drive shaft 47) will be described in detail later.

The sensor substrate 48 is formed in an annular shape and is fixed to the rear end of the stator 41 with screws so as to partially cover the opening at the rear end of the stator 41. A hall sensor (not shown) for detecting the rotation position (rotation angle) of the rotor 45 is mounted on the sensor board 48.

The compression mechanism 6 will be described.

As shown in FIG. 6, in the present embodiment, the compression mechanism 6 includes three fans (also referred to as impellers) 60. The fan 60 is fixed on the drive shaft 47 and is configured to rotate around the rotation shaft A1 integrally with the drive shaft 47 as the motor 4 is driven. The fan 60 is a centrifugal fan that sucks air in the direction of the rotation axis A1 and sends it out in the radial direction.

The three fans 60 are arranged in three areas (also referred to as rooms) partitioned by three partition plates 71, respectively. More specifically, three circular partition plates 71 having a through hole in the central portion are arranged in the main body housing 2. The partition plates 71 are arranged on the rear side (which can also be said to be the front stage side or the suction port 201 side) of the three fans 60, respectively. The rearmost partition plate 71 divides the internal space of the main body housing 2 into an accommodation area of the motor 4 and an accommodation area of the fan 60. The outer diameter of the partition plate 71 is substantially equal to the inner diameter of the main body housing 2 (cylindrical portion 21). A through hole at the center of each partition plate 71 is arranged on the rotation axis A1. Each partition plate 71 through hole constitutes a vent for communicating the region of the front stage (rear side) and the region of the next stage (front side).

Further, a rectifying member 73 is arranged on the front side (which can be said to be the next stage side and the discharge port 203 side) of each of the two fans 60 in the first stage and the second stage. Each rectifying member 73 is configured to direct the air sent out by the fan 60 inward in the radial direction and guide the air to the next stage through the vent of the next partition plate 71. The two rectifying members 73 have the same configuration. Further, a rectifying member 75 is arranged on the front side of the fan 60 in the third stage (frontmost). The rectifying member 75 is configured to direct the air sent out radially outward by the fan 60 to the radial inward and guide it to the discharge port 203. The rectifying member 75 also serves as a holding member for the bearing 477, and has a bottomed cylindrical bearing holding portion 755. The partition plate 71 and the rectifying

members

73, 75 are positioned in the front-rear direction and are fixedly held with respect to the tubular portion 21.

When the motor 4 is driven and the three fans 60 rotate integrally with the drive shaft 47, air is sucked into the main body housing 2 from the suction port 201 (see FIG. 3). The sucked air passes through the accommodating area of the motor 4 while cooling the motor 4, and flows into the accommodating area of the fan 60 from the vent of the rearmost (uppermost stream side) partition plate 71. In the two regions of the first stage and the second stage, the air sucked in the rotation axis A1 direction by the fan 60 and sent out in the radial direction is guided in the radial direction by the rectifying member 73, and is guided to the next section. It flows into the next region from the vent of the plate 71. Further, in the third stage region, the air sucked in the rotation axis A1 direction by the fan 60 and sent out radially outward is guided in the radial direction by the rectifying member 75, and the nozzle 231 of the front cover 23 is guided. It passes through and is discharged from the discharge port 203.

The compression mechanism 6 is configured to compress the air sucked from the suction port 201 by the three centrifugal fans 60 arranged in multiple stages in this way and discharge the air from the discharge port 203. In the compression mechanism 6 having such a configuration, the specifications of the fan 60 (for example, the number of fans 60, the outer diameter of the blades of the fan 60, etc.), the rotation speed of the fan 60 (that is, the rotation speed of the motor 4), and the like are appropriate. Depending on the setting, the wind force of the discharged compressed air can be efficiently increased. In the present embodiment, the outer diameter of the blade of the fan 60 is set to 50 mm (mm). The maximum number of revolutions of the motor 4 is set to 50,000 revolutions per minute (50,000 rpm). The air duster 1 is configured to be capable of exerting a wind force of about 1.5 Newton (N) when the motor 4 is driven at the maximum rotation speed. This wind power is sufficient to blow off dust and the like. The value of this wind power is a value measured according to the "ANSI B175.2 standard" defined by the American National Standards Institute (abbreviated as ANSI).

The internal structure of the handle housing 3 will be described below.

As shown in FIG. 2, the switch 333 is housed in the grip portion 33. The switch 333 is always kept in the off state, and is turned on in response to the pulling operation of the trigger 331. The switch 333 is connected to the controller 351 via a wiring (not shown). When the switch 333 is turned on, the switch 333 is configured to output a signal corresponding to the operation amount (pull amount) of the trigger 331 to the controller 351.

The controller 351 is housed in the controller housing section 35. The controller 351 is configured to control various operations of the air duster 1 such as drive control of the motor 4. In the present embodiment, the controller 351 is configured as a microcomputer including a CPU, ROM, RAM, and memory. In the present embodiment, the controller 351 is configured to steplessly control the rotation speed of the motor 4 according to the signal output from the switch 333 (that is, the operation amount of the trigger 331).

A battery mounting portion 37 is provided at the lower end of the controller accommodating portion 35. The battery mounting portion 37 has an engaging structure in which the rechargeable battery 370 can be slidably engaged, and a terminal that can be connected to the terminal of the battery 370 as the battery 370 is engaged. Since the configurations of the battery mounting portion 37 and the battery 370 are well known, the description thereof will be omitted here.

Hereinafter, the support structure of the motor 4 inside the main body housing 2 will be described.

First, the support structure of the stator 41 will be described.

As shown in FIGS. 4 and 5, the stator 41 is fixedly supported by the main body housing 2 via a support 5 arranged between the stator 41 and the tubular portion 21 in the radial direction of the stator 41. ing.

Hereinafter, the overall configuration of the support 5 will be described. Even when the support 5 is shown alone, the direction of the support 5 shall be the same as the direction of the air duster 1 when assembled to the main body housing 2 together with the stator 41.

As shown in FIGS. 4, 5 and 7 to 9, the support 5 is a tubular body as a whole, and includes a wall portion surrounding the stator 41 in the circumferential direction around the rotation axis A1. The thickness of the support 5 (wall portion) is set to approximately 3.5 mm. The support 5 includes a stator holding portion 51 and a gap forming portion 55.

The stator holding portion 51 is a wall portion having an inner peripheral surface that matches the outer peripheral surface of the stator 41. The stator holding portion 51 is configured to come into contact with the outer peripheral surface of the stator 41 and hold the stator 41 so as to be immovable in the radial direction. The stator holding portion 51 includes an upper holding portion 52 forming an upper wall portion of the support 5, and a lower holding portion 53 forming a lower wall portion of the support 5. The gap forming portion 55 is a wall portion that protrudes radially outward from the stator holding portion 51. The inner peripheral surface of the gap forming portion 52 is separated radially outward from the outer peripheral surface of the stator 41. That is, a gap is formed between the outer peripheral surface of the stator 41 and the inner peripheral surface of the gap forming portion 55. This gap extends from the front end to the rear end of the support 5 in the extending direction (front-back direction) of the rotating shaft A1 and functions as a ventilation passage 56 through which air can pass. The gap forming portion 55 has a left wall portion connecting the left ends of the upper holding portion 52 and the lower holding portion 53, and a right wall portion connecting the right ends of the upper holding portion 52 and the lower holding portion 53, respectively. Including.

As described above, in the support 5 of the present embodiment, the two stator holding portions 51 and the two gap forming portions 55 are alternately arranged in the circumferential direction. As shown in FIG. 10, the front end of the gap forming portion 55 is on the same surface as the front end of the stator holding portion 51, but the rear end of the gap forming portion 55 is behind the rear end of the stator holding portion 51. Located on the side. That is, the gap forming portion 55 projects rearward from the stator holding portion 51.

In this embodiment, the support 5 is made of synthetic resin. The support 5 is preferably made of a synthetic resin having high heat resistance and low water absorption. An example of such a synthetic resin is POM (polyoxymethylene) (also referred to as polyacetal resin). Further, as shown in FIGS. 10 to 12, in the present embodiment, the support 5 is formed by connecting the left side member 501 and the right side member 502, which are formed as separate bodies from each other. The left side member 501 and the right side member 502 are formed substantially symmetrically (including the rotation axis A1 and symmetrically with respect to the plane P extending in the vertical direction). That is, it can be said that the support 5 is formed by connecting half-split bodies divided into left and right on a plane including the rotation axis A1.

Hereinafter, the details of the holding structure of the stator 41 by the support 5 will be described.

In the present embodiment, the support 5 holds the stator 41 in a state of being positioned in the front-rear direction and the circumferential direction. Therefore, the support 5 and the stator 41 have a configuration for positioning.

First, the positioning of the stator 41 in the front-rear direction will be described. As shown in FIGS. 7, 11 and 12,

protrusions

521 and 531 are provided on the inner circumferences of the front ends of the upper holding portion 52 and the lower holding portion 53 of the support 5. The protrusions 521 and 513 project inward in the radial direction, and by abutting the front ends of the upper end portion and the lower end portion of the stator 41, respectively, the position of the stator 41 with respect to the support 5 is defined in the front-rear direction.

Next, the positioning of the stator 41 in the circumferential direction will be described.

As shown in FIGS. 5, 7 and 12, a groove 522 is formed on the inner circumference of the central portion of the upper holding portion 52 of the support 5 in the left-right direction. The groove 522 is a linear groove extending forward from the rear end of the support 5 to the protrusion 521. On the other hand, a ridge 423 is provided on the outer periphery of the central portion of the upper end portion of the stator 41 in the left-right direction. The ridge 423 has a semicircular cross section and extends linearly in the front-rear direction. At the rear end of the ridge 423, a screw hole for fixing the sensor substrate 48 to the stator 41 is provided. Further, as described above, the terminal mounting portion 417 is arranged on the radial outer side of the lower rear end portion of the stator 41. Therefore, as shown in FIGS. 5, 7 and 10, the lower holding portion 53 is provided with a recess 537 for securing a space in which the terminal mounting portion 417 can be arranged. The recess 537 is a recess that is recessed forward from the rear end of the lower holding portion 53.

Further, as shown in FIGS. 5 and 12, a part of the inner peripheral surface of the upper holding portion 52 includes a plane 523 parallel to the rotation axis A1. On the other hand, a part of the outer peripheral surface of the upper end portion of the stator 41 includes a plane 421 that is aligned with the plane 523.

In the support 5, the ridge 423 is arranged in the groove 522, the terminal mounting portion 417 is arranged in the recess 537, and the flat surface 421 faces the flat surface 523 with a slight gap. Arranged on the outside in the radial direction. Thereby, the position of the stator 41 with respect to the support 5 is defined in the circumferential direction. Further, the rotation of the stator 41 with respect to the support 5 in the circumferential direction is restricted.

Hereinafter, the details of the support structure of the support 5 by the main body housing 2 will be described.

In the present embodiment, the main body housing 2 supports the support 5 in a state of being positioned in the front-rear direction and the circumferential direction. Therefore, the main body housing 2 and the support 5 have a configuration for positioning.

First, the positioning of the support 5 in the front-rear direction will be described.

As shown in FIGS. 4 and 5, the tubular portion 21 has four ribs 211 protruding radially inward (toward the rotation axis A1) from the inner peripheral surface. The four ribs 211 are arranged at substantially equal intervals in the circumferential direction, and project from diagonally upward and diagonally downward on the left and right with respect to the rotation axis A1. Further, as shown in FIG. 8, the rib 211 extends forward from the rear end of the tubular portion 21 to a position slightly rearward of the central portion. The length of the rib 211 in the front-rear direction is larger than the maximum length of the support 5 (the length of the gap forming portion 55 in the front-rear direction). A protrusion 212 that further protrudes inward in the radial direction is provided at the front end of the rib 211. A screw hole is provided at the rear end of the rib 211.

Of the four ribs 211, the protruding height (length in the radial direction) of the portion other than the protrusion 212 is set so that the support 5 (specifically, the stator holding portion 51) can be press-fitted inward in the radial direction of the rib 211. Has been done. On the other hand, the protruding height of the protrusion 212 is set so that the protruding end (radial inner end) of the protrusion 212 is located radially inside the outer circumference of the support 5.

The four ribs 211 configured as described above support the support 5 so as not to move in the radial direction, and define the position of the support 5 with respect to the main body housing 2 in the front-rear direction. More specifically, as shown in FIGS. 4, 5 and 8, the protruding end faces of the four ribs 211 other than the protrusion 212 come into contact with the outer peripheral surface of the stator holding portion 51 from the radial outside to support the support. Supports 5 immovably in the radial direction. Further, the rear end surfaces of the protrusions 212 of the four ribs 211 come into contact with the front end surfaces of the stator holding portion 51 from the front, and define the position of the support 5 with respect to the main body housing 2 in the front-rear direction. As shown in FIG. 8, the front end surface of the rib 211 abuts on the rear surface of the rearmost partition plate 71 from the rear, and also defines the position of the partition plate 71 in the front-rear direction.

Further, as shown in FIG. 13, the rear cover 25 has two projecting pieces 251. The projecting pieces 251 are provided at the left end and the right end of the rear cover 25, and project forward in parallel with the rotation axis A1. Further, the rear cover 25 has four through holes through which screws can be inserted. As shown in FIG. 8, the rear cover 25 is fitted into the rear end portion of the tubular portion 21, and the screw is screwed into the screw hole of the rib 211 through the through hole to form the tubular portion 21. It is fixed. As shown in FIG. 9, the protruding ends (front end faces) of the two protruding pieces 251 are supported by abutting on the rear ends (specifically, the rear end faces of the pair of left and right gap forming portions 55) of the support body 5. Regulate the backward movement of body 5. As a result, the support 5 is held by the rib 211 and the projecting piece 251 so as not to be movable in the front-rear direction with respect to the main body housing 2. As described above, in the present embodiment, the rear cover 25 also functions as a rearward movement restricting portion of the support 5 while covering the opening at the rear end of the tubular portion 21.

Next, the positioning of the support 5 in the circumferential direction will be described.

As shown in FIGS. 4 and 5, the four ribs 211 of the tubular portion 21 are formed at the boundary between the upper and lower stator holding portions 51 and the left and right gap forming portions 55 of the support 5 (stator). It projects so as to be adjacent to four shoulder portions (step portions) 57 (connecting the holding portion 51 and the gap forming portion 55). Further, as shown in FIGS. 4, 5 and 7, the upper rear end portion and the lower rear end portion of the tubular portion 21 are provided with protruding

portions

214 and 215 protruding downward and upward, respectively. .. The protrusion 215 is arranged in front of the protrusion 214. The lower end surface of the projecting portion 214 and the upper end surface of the projecting portion 215 are configured as a pair of

planes

216 and 217 parallel to the rotation axis A1 and parallel to each other, respectively. On the other hand, a part of the outer peripheral surface of the upper holding portion 52 of the support 5 and a part of the outer peripheral surface of the lower holding portion 53 include a pair of

planes

525 and 535 consistent with the pair of

planes

216 and 217.

The support 5 has a tubular portion in which four ribs 211 and four shoulder portions 57 are adjacent to each other, and planes 216 and 217 face each other with a slight gap between

planes

525 and 535. It is arranged in 21. Thereby, the position of the support 5 with respect to the main body housing 2 is defined in the circumferential direction. Further, the rotation of the support 5 with respect to the main body housing 2 in the circumferential direction is restricted.

As described above, in the present embodiment, the support 5 is formed by the left side member 501 and the right side member 502 (see FIG. 11). Therefore, the operator assembles the stator 41 to the main body housing 2 in the following procedure.

First, the operator holds the stator 41 with the support 5. At this time, according to the above configuration, the operator can easily position the support 5 and the stator 41 in the front-rear direction and the circumferential direction. In particular, since the operator only needs to sandwich the stator 41 from the left and right between the left side member 501 and the right side member 502, which are separate members, it is very easy to hold the stator 41 by the support 5. Further, the operator pushes the support 5 holding the stator 41 forward along the protruding end faces of the four ribs 211 through the opening at the rear end of the tubular portion 21, and press-fits the support 5 forward. At this time, according to the above configuration, the operator can easily position the tubular portion 21 and the support 5 in the front-rear direction and the circumferential direction.

The support 5 holding the stator 41 is pressed by the ribs 211 so that the left side member 501 and the right side member 502 are in close contact with each other, and the inner peripheral surface of the stator holding portion 51 is in close contact with the outer peripheral surface of the stator 41. .. As a result, the stator 41 is firmly held by the support 5, and is supported by the tubular portion 21 via the support 5. Further, the operator fixes the rear cover 25 to the tubular portion 21 with screws. By the above procedure, the stator 41 is fixedly supported by the main body housing 2 via the support body 5.

The details of the support structure of the motor shaft 471 will be described below.

As described above, the motor shaft 471 constitutes the integrated drive shaft 47 together with the extension shaft 473. As shown in FIG. 6, the drive shaft 47 is rotatably supported by

bearings

477 and 478.

In the present embodiment, the bearing 477 that supports the front portion of the drive shaft 47 (specifically, the extension shaft 473) is fitted into the bearing holding portion 755 of the rectifying member 75, and the tubular portion 21 is fitted via the rectifying member 75. It is held in. The bearing 478 that supports the rear end of the drive shaft 47 (specifically, the motor shaft 471) is held by the rear cover 25. That is, the rear cover 25 also functions as a holding member for the bearing 478. More specifically, a bottomed cylindrical bearing holding portion 255 is provided at the center of the rear cover 25. The bearing 478 is fitted in the bearing holding portion 255 and is held by the rear cover 25.

As described above, in the air duster 1 of the present embodiment, the tubular portion 21 of the main body housing 2 accommodating the motor 4 is made of metal having higher strength than the synthetic resin. Therefore, even if a high-speed motor 4 having a maximum rotation speed of 50,000 rpm is adopted in order to obtain a large amount of wind power, the durability of the tubular portion 21 can be maintained satisfactorily. In particular, in the present embodiment, the compression mechanism 6 (fan 60) is also housed in the tubular portion 21. By accommodating the motor 4 and the compression mechanism 6 in a single metal tubular member in this way, the leakage of air from the tubular portion 21 is suppressed, and the decrease in pressure inside the main body housing 2 is suppressed. be able to.

Further, in the present embodiment, the stator 41 is supported by the tubular portion 21 via a support 5 arranged on the radial outer side of the stator 41. By arranging the support 5 made of synthetic resin between the stator 41 and the metal tubular portion 21 in this way, a sufficient distance can be provided between the conductor of the stator 41 and the tubular portion 21. It can be secured and the possibility that the tubular portion 21 affects the motor 4 can be reduced. For example, as shown in FIG. 5, the stator 41 is provided with a metal terminal 415 to which the lead wire of the coil is connected. An insulating distance is secured between the terminal 415 and the tubular portion 21 by the support 5.

Further, in the present embodiment, the rear cover 25 that covers the opening at the rear end of the tubular portion 21 is also made of metal, so that a rational configuration that also serves as a holding member for the bearing 478 is realized. Further, the rear cover 25 can regulate the movement of the support 5 by the protruding piece 251, and a more rational configuration is realized. There are only two projecting pieces 251 and they come into contact with the rear end of the gap forming portion 55 of the support 5, which projects rearward from the stator holding portion 51. As a result, the influence of the metal rear cover 25 on the motor 4 can be suppressed.

Further, in the present embodiment, the support 5 has a gap forming portion 55 that forms a ventilation passage 56 between the support 5 and the stator 41. As a result, the motor 4 can be effectively cooled by the air passing through the ventilation path. In particular, in the present embodiment, the support 5 is provided on the front side of the rear cover 25 having the suction port 201, and the ventilation passage 56 extends in the front-rear direction. Further, a compression mechanism 6 including three fans (centrifugal fans) 60 is provided on the front side of the support 5. Therefore, the air that has flowed into the tubular portion 21 from the suction port 201 passes through the ventilation passage 56 from the rear to the front and reaches the compression mechanism 6. In this way, the support 5 realizes an efficient flow path that quickly guides the air flowing into the tubular portion 21 to the compression mechanism 6 while using it for cooling the motor 4.

The correspondence between each component of the above embodiment and each component of the present invention is shown below. However, each component of the embodiment is merely an example, and does not limit each component of the present invention. The air duster 1 is an example of a "blower". The motor 4, the stator 41, the rotor 45, and the motor shaft 471 are examples of a "motor", a "stator", a "rotor", and an "output shaft", respectively. The compression mechanism 6 is an example of a “compression mechanism”. The tubular portion 21 is an example of a “housing”. The support 5 is an example of a “support”.

The rib 211 and the shoulder portion 57 are examples of the "first positioning portion". Plane 216 and plane 525 are another example of the "first positioning unit". Plane 217 and plane 535 are another example of the "first positioning unit". The groove 522 and the ridge 423 are examples of the "second positioning portion". Plane 523 and plane 421 are another example of a "second positioning unit". The ventilation path 56 is an example of a “ventilation path”. The stator holding portion 51 and the gap forming portion 55 are examples of the “first wall portion” and the “second wall portion”, respectively. The rib 211 and the shoulder portion 57 are examples of the “protruding portion” and the “shoulder portion”, respectively. The protrusion 212 is an example of a “protrusion”. The left side member 501 and the right side member 502 are examples of "plurality of members". Bearing 478 is an example of a "bearing". The rear cover 25 is an example of a “cover”. The protruding piece 251 is an example of a "contact portion". The fan 60 is an example of a “centrifugal fan”.

Note that the above embodiment is merely an example, and the blower according to the present disclosure is not limited to the illustrated air duster 1. For example, the changes illustrated below can be made. It should be noted that only one or a plurality of these changes may be adopted in combination with the air duster 1 shown in the embodiment or the features described in each claim.

For example, the numerical values of the specifications of the air duster 1 (the wind force of the compressed air discharged from the discharge port 203, the outer diameter of the blades of the fan 60, the maximum rotation speed of the motor 4, etc.) exemplified in the above embodiment are merely examples. Different numbers may be adopted. The wind speed of the compressed air discharged from the discharge port 203 is preferably in the range of 1N to 3N. In this case, the air duster 1 can exert sufficient wind power to blow off dust and the like. Further, in order to increase the wind power, the maximum rotation speed of the motor 4 is preferably 50,000 rpm or more.

The power source of the air duster 1 is not limited to the rechargeable battery 370, and may be a disposable battery or an external AC power source. Further, the air duster 1 may have a built-in rechargeable battery.

The configuration of the support 5, the support structure of the support 5 by the main body housing 2, and the holding structure of the stator 41 by the support 5 can be changed as appropriate. The changes that can be adopted are illustrated below.

For example, the support 5 may be configured as a single tubular body instead of being composed of a plurality of members. In the above embodiment, the left side member 501 and the right side member 502 are fitted into the tubular portion 21 and are connected in the circumferential direction (held in close contact with each other). However, the left side member 501 and the right side member 502 may be engaged with each other and inseparably connected, or may be connected and fixed with screws. Further, the support 5 is not a half-split body divided into two on the left and right (left side member 501 and right side member 502), but a half-split body (for example, an upper member and a lower member) divided into two in different directions. It may be formed by being connected. The plurality of members constituting the support 5 may not be evenly divided in the circumferential direction, or may be asymmetric with respect to the plane including the rotation axis A1. Further, the support 5 may be composed of a plurality of members that do not come into contact with each other. The number of the plurality of members may be 3 or more.

The support 5 does not need to have the gap forming portion 55 forming the ventilation passage 56, and the support 5 may be configured so that substantially the entire support 5 abuts on the outer peripheral surface of the stator 41. Further, the number of gap forming portions 55 may be 1 or 3 or more. The circumferential positioning of the stator 41 by the support 5 may be performed at only one location (for example, only the groove 522 and the ridge 423), or another positioning configuration may be adopted.

The shape of the tubular portion 21 may be changed to a rectangular tubular shape or the like instead of a cylindrical shape. The number of ribs 211 that support the support 5 may be a number other than 4. In the above embodiment, the rib 211 is configured so that the support 5 can be positioned in the front-rear direction and the circumferential direction with respect to the tubular portion 21, but only one of the front-rear direction and the circumferential direction can be positioned. There may be. Another positioning configuration may be adopted. Further, the rib 211 may be omitted, and the inner peripheral portion of the rear end portion of the tubular portion 21 may be configured so that the support 5 can be fitted. Further, a groove extending in the front-rear direction may be provided in the tubular portion 21, and a ridge that can be fitted into the groove may be provided on the outer periphery of the support 5.

Further, the configuration of the main body housing 2 and the handle housing 3 and the arrangement of the internal structure can be changed as appropriate. For example, the size, shape, arrangement, etc. of the suction port 201 and the discharge port 203 may be appropriately changed from the example of the above embodiment. For example, the motor 4 may be arranged not between the suction port 201 and the first stage fan 60 but between the final stage fan 60 and the discharge port 203. The rear cover 25 may only have a function of covering the opening at the rear end of the tubular portion 21. In this case, the bearing 478 can be held in the main body housing 2 via a member different from the rear cover 25. Further, the rear cover 25 may be made of resin instead of metal.

The compression mechanism 6 for generating compressed air can be changed as appropriate. For example, the number of fans 60 (that is, the number of stages), the shape, number, outer diameter, and the like of the blades of the fan 60 can be appropriately selected according to, for example, the wind power required for the air duster 1. Further, the arrangement of the fan 60, the partition plate 71, and the rectifying

members

73, 75 in the main body housing 2 and the configuration of the partition plate 71, the rectifying

members

73, 75 can be changed as appropriate.

Further, in view of the purpose of the present invention, the above-described embodiment, and its modifications, the following aspects are constructed. Only one or more of these can be employed in combination with the Air Duster 1 shown in the embodiments and the modifications described above, or the features described in each claim.

[Aspect 1]
The first positioning portion is provided on one of the inner peripheral portion of the housing and the outer peripheral portion of the support, and the inner peripheral portion of the housing and the other of the supports, and the peripheral portion is provided. Includes a contact portion capable of contacting the protruding portion in the direction.
The rib 211 and the shoulder portion 57 are examples of the “protruding portion” and the “contact portion” in this embodiment, respectively.
[Aspect 2]
A first cover that covers the opening at one end of the housing and has a suction port for sucking air into the housing.
A second cover having the discharge port is further provided while covering the opening at the other end of the housing.
The stator and the rotor of the motor are arranged between the first cover and the first-stage centrifugal fan among the plurality of centrifugal fans.
The rear cover 25 and the front cover 23 are examples of the "first cover" and the "second cover" in this embodiment, respectively.
[Aspect 3]
The ventilation path extends in the axial direction of the output shaft.
[Aspect 4]
The second positioning portion is provided on one of the inner peripheral portion of the support and the outer peripheral portion of the stator, and the other of the inner peripheral portion of the support and the outer peripheral portion of the stator. , Including a concave portion that can be engaged with the convex portion.
The ridge 423 and the groove 522 are examples of the "convex portion" and the "concave portion" of this embodiment, respectively.
[Aspect 5]
At least one of the housing and the support includes a third positioning portion configured to position the housing and the support in the axial direction of the output shaft.
The rib 211 (projection 212) is an example of the “third positioning portion” of this embodiment.
[Aspect 6]
At least one of the support and the stator includes a fourth positioning portion configured to position the support and the stator in the axial direction of the output shaft.
Each of the

protrusions

521 and 531 is an example of the "fourth positioning portion" of this embodiment.
[Aspect 7]
The support includes a short wall portion having a first length in the axial direction of the output shaft and a long wall portion having a second length longer than the first length in the axial direction. The contact portion of the cover abuts on the long wall portion.
The stator holding portion 51 and the gap forming portion 55 are examples of the “short wall portion” and the “long wall portion” of this embodiment, respectively.
[Aspect 8]
The blower further comprises an outer cover made of synthetic resin that covers at least a portion of the housing.
The cover portion 31 is an example of the “outer cover” of this embodiment.

1: Air duster 2: Main body housing, 201: Suction port, 203: Discharge port, 21: Cylindrical part, 211: Rib, 212: Projection, 214: Projection part, 215: Projection part, 216: Flat surface, 217: Flat surface , 23: Front cover, 231: Nozzle, 25: Rear cover, 251: Projection piece, 255: Bearing holder 3: Handle housing, 301: Left shell, 302: Right shell, 31: Cover, 32: Gripping Part, 33: Grip part, 331: Trigger, 333: Switch, 35: Controller housing part, 351: Controller, 37: Battery mounting part, 370: Battery, 4: Motor, 41: Stator, 415: Terminal, 417: Terminal Mounting part, 421: flat surface, 423: ridge, 45: rotor, 47: drive shaft, 471: motor shaft, 473: extension shaft, 477: bearing, 478: bearing, 48: sensor board, 5: support, 501: Left side member, 502: Right side member, 51: Stator holding part, 52: Upper holding part, 521: Protrusion, 522: Groove, 523: Flat surface, 525: Flat surface, 53: Lower holding part, 531: Protrusion, 535 : Flat surface, 537: Concave, 55: Gap forming part, 56: Ventilation path, 57: Shoulder part, 6: Compression mechanism, 60: Fan, 71: Partition plate, 73: Rectifying member, 75: Rectifying member, 755: Bearing Holding part, A1: Rotation axis, P: Plane

Claims

An electric blower configured to discharge compressed air from the discharge port.
A brushless motor including a stator, a rotor, and an output shaft that can rotate around a first axis integrally with the rotor.
A compression mechanism driven by the motor and configured to generate the compressed air,
At least a metal tubular housing that houses the motor,
A synthetic resin support arranged between the stator and the housing in the radial direction of the stator is provided.
A blower characterized in that the stator is supported by the housing via the support.
The blower according to claim 1.
A blower characterized in that at least one of the housing and the support includes a first positioning portion configured to position the housing and the support in a circumferential direction around the first axis.
The blower according to claim 1 or 2.
A blower characterized in that at least one of the support and the stator includes a second positioning portion configured to position the support and the stator in a circumferential direction around the first axis.
The blower according to any one of claims 1 to 3.
The blower is characterized in that the support is configured to form a ventilation path between the support and the stator.
The blower according to claim 4.
The support is a tubular body and has a tubular body.
The support
At least one first wall portion that comes into contact with the outer peripheral surface of the stator,
It includes at least one second wall portion that protrudes radially outward of the at least one first wall portion.
The blower is characterized in that the ventilation passage is formed by a gap formed between the outer peripheral surface of the stator and the inner peripheral surface of the at least one second wall portion.
The blower according to claim 5.
The housing comprises at least one protrusion that projects radially inwardly of the housing, abuts on the outer peripheral surface of the support, and supports the support substantially immovably in the radial direction.
The at least one protrusion is formed on at least one shoulder portion between the at least one first wall portion and the at least one second wall portion of the support in the circumferential direction around the first axis. A blower characterized by being arranged adjacent to each other.
The blower according to claim 6.
The blower, wherein the at least one protrusion has a protrusion that abuts on the support in the axial direction of the output shaft.
The blower according to any one of claims 1 to 7.
The support is a blower characterized by being composed of a plurality of members.
The blower according to any one of claims 1 to 8.
A bearing that rotatably supports one end of the output shaft,
A blower that holds the bearing and further comprises a metal cover configured to cover an opening at one end of the housing.
The blower according to claim 9.
The cover is a blower that comes into contact with the support and has a contact portion configured to restrict the support from moving toward the cover in the axial direction of the output shaft.
The blower according to claim 10.
The blower is characterized in that the contact portion is configured as a protrusion protruding toward the stator side in the axial direction of the output shaft.
The blower according to any one of claims 1 to 11.
The blower is characterized in that the compression mechanism is arranged in multiple stages coaxially with the output shaft, and includes a plurality of centrifugal fans configured to rotate around the first axis as the motor is driven.
The blower according to claim 12.
The housing is a blower that houses the compression mechanism.