JP2007205285A - Electric blower - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric blower which restrains sliding resistance between a centrifugal fan and a seal member and capable of restraining the whole length in an axial direction. <P>SOLUTION: An outer side of the seal member 96 in a peripheral direction is formed to be thinner than an inner side. A contact area of a tilted protruding part 88 of a front surface shroud 76 of the centrifugal fan 5 slidably brought into contact with the seal member 96 and the seal member 96 is restrained, and the sliding resistance between the centrifugal fan 5 and the seal member 96 is reduced. Even when the protruding part 88 of the centrifugal fan 5 is tilted, the sliding resistance is not increased, and the whole length of the electric blower in the axial direction is thereby restrained. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electric blower including an annular seal member in which a protruding portion of a centrifugal fan is slidably contacted to the outside to close a gap between a peripheral edge of a suction port and a fan cover.

  2. Description of the Related Art Conventionally, for example, an electric blower used for a vacuum cleaner or the like has a motor having a rotating shaft in a substantially cylindrical main body case, and the rotating shaft of the motor has a ventilation hole formed in a central portion thereof. It has a front plate part in which the peripheral part of the hole protrudes in an inclined manner toward the front side, and a rear plate part spaced rearward from the front plate part, and a fan blade is formed between these plate parts A centrifugal fan is installed.

A rectifying plate is provided between the motor and the centrifugal fan to rectify the air blown from the centrifugal fan in a spiral shape in the direction of the central axis on the motor side. Furthermore, a fan cover that covers the centrifugal fan is attached to the main body case. A suction port communicating with the ventilation hole is opened at the center of the fan cover. Furthermore, an annular seal member is attached to the peripheral edge of the suction port on the inner surface of the fan cover so that the protrusion of the front plate portion of the centrifugal fan is in sliding contact with the rear end surface. The sealing member has a substantially quadrangular cross section, and the projecting portion of the centrifugal fan is pressure-contacted at the manufacturing stage, and the rear end surface side is cut by the projecting portion when the centrifugal fan is rotated. It is comprised so that a suction inlet and the ventilation hole of a centrifugal fan may be connected airtight (for example, refer patent document 1).
JP 2000-175850 A (page 3, FIG. 1)

  However, in the electric blower described above, since the cross section of the sealing member is formed in a square shape, when using a so-called mixed flow type centrifugal fan in which the peripheral edge of the ventilation hole is curved toward the fan cover side. Since the peripheral edge of the ventilation hole slides in contact with the sealing member on the surface in an inclined manner, the pressure on the sealing member of the projecting portion of the centrifugal fan that is in pressure contact cannot be secured sufficiently, and the sealing member cannot be cut efficiently. There is a problem that the sliding resistance between the centrifugal fan and the seal member is increased. And if sliding resistance becomes large like this, it will become a load at the time of operation of an electric blower, and the improvement of the performance of an electric blower cannot be aimed at.

  On the other hand, in order to suppress the sliding resistance, the protruding portion of the centrifugal fan must be substantially perpendicular to the rear end surface of the sheet member. Therefore, the entire thickness of the centrifugal fan is increased by the amount that the protruding portion protrudes vertically. There is also a problem that it is not easy to suppress the overall length of the electric blower in the axial direction.

  This invention is made | formed in view of such a point, and it aims at providing the electric blower which can suppress the sliding resistance of a centrifugal fan and a sealing member, and can suppress the full length of an axial direction.

  The present invention includes a plate that has an opening at the suction port, and has a plate portion that protrudes in an inclined manner toward the center side of the suction port at the peripheral portion of the suction port, and is attached to one end side of the rotating shaft. A fan, a fan cover that covers the centrifugal fan and is attached to the main body case, and an annular seal member that slides in contact with the protrusion of the centrifugal fan and closes a gap between the peripheral edge of the suction port and the fan cover. The outer side in the circumferential direction of the seal member is formed thinner than the inner side.

  According to the present invention, by forming the outer side in the circumferential direction of the seal member thinner than the inner side, the contact area between the inclined protruding portion of the plate portion of the centrifugal fan that is in sliding contact with the seal member and the seal member is suppressed. The sliding resistance can be reduced, the amount of protrusion of the protruding portion of the centrifugal fan can be suppressed, and the total length in the axial direction can be suppressed.

  Hereinafter, the configuration of an electric blower according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

  FIG. 2 shows an electric blower 1, and this electric blower 1 is used, for example, in a vacuum cleaner (not shown) or an industrial blower. In the electric blower 1, a motor 2 is disposed in a substantially bottomed cylindrical main body case 3, and is rotated outside the main body case 3 by a rectifying current plate 4 and a motor 2. The centrifugal fan 5 is sequentially attached from the motor 2 side, and the centrifugal fan 5 is covered with a fan cover 6.

  In the following description, the motor 2 side is the rear side and the fan cover 6 side is the front side.

  The motor 2 is a rotating shaft 11 disposed along the central axis of the main body case 3, a commutator 12 as a cylindrical commutator provided on the outer peripheral surface of the rotating shaft 11, and an armature as a rotor. An armature 13, a stator 14 as a stator, and carbon brush assemblies 15 and 15 as a pair of brush mechanism portions are provided.

  The rotary shaft 11 has a front end portion that is the other end portion in the axial direction inserted through the rectifying plate 4, and a centrifugal fan 5 is attached to the front end portion.

  The commutator 12 has conductivity, is fixed to the outer peripheral surface of the rotating shaft 11 and rotates integrally with the rotating shaft 11, and the tip portions of the carbon brush assemblies 15, 15 are in sliding contact with the outer peripheral surface.

  The armature 13 is fixed to the outer peripheral surface of the rotary shaft 11 ahead of the commutator 12 and is disposed on the inner peripheral side of the stator 14 and is electrically connected to the commutator 12.

  The stator 14 has a square plate-like stator core 21 in plan view in which a large number of iron plates are stacked, and a substantially square insertion hole 22 into which the armature 13 is inserted is formed at the center of the stator core 21. The insertion hole portion 22 has an inner peripheral portion facing the outer peripheral surface of the armature 13 with a predetermined gap. A plurality of fixed poles, that is, an N pole and an S pole are formed on the inner peripheral portion of the stator core 21.

  Each carbon brush assembly 15 is fixed by inserting a tip portion into a pair of brush portion mounting holes 24 (only one is shown) formed in the main body case 3. Each carbon brush assembly 15 is provided in a carbon brush 25, a brush holder 26 that holds the carbon brush 25, a spring 27 as an urging member accommodated in the brush holder 26, and the brush holder 26. And a terminal 28.

  The carbon brush 25 has one end portion in the longitudinal direction protruding from the brush holder 26 in the direction of the central axis of the main body case 3 to be in sliding contact with the outer peripheral surface of the commutator 12 and being electrically connected to the commutator 12, and the other end in the longitudinal direction. The part is inserted into the brush holder 26.

  The brush holder 26 has one end portion in the longitudinal direction of the carbon brush 25 inserted into the brush portion mounting hole 24, and the other end portion in the longitudinal direction protrudes outward from the main body case 3.

  The spring 27 presses the carbon brush 25 against the outer peripheral surface of the commutator 12.

  The terminal 28 protrudes from the other end of the brush holder 26 in the longitudinal direction, and is electrically connected to a household commercial AC power source or a power source unit (not shown) such as a battery.

  The main body case 3 includes a body frame 31 as a substantially bottomed cylindrical case body, and a frame 32 as a rotor support plate attached to the front end of the body frame 31 and supporting the armature 13 in the axial direction. ing.

  The body frame 31 is provided with a cylindrical motor head portion 34 protruding rearward at the rear end surface, ie, the center of the bottom surface, which is one end in the axial direction. Further, an opening 35 to which the frame 32 is attached is formed at the front end portion of the body frame 31, and a flange portion 36 to which both ends of the frame 32 are fixed protrudes from the peripheral portion of the opening 35. ing. Further, on the outer peripheral surface near the front end portion of the body frame 31, a pair of brush portion mounting holes 24 (only one is shown) to which the carbon brush assemblies 15, 15 are respectively attached, and air blown from the centrifugal fan 5 are externally provided. A plurality of square hole-like exhaust ports 38 (only one is shown) are formed in the respective holes.

  The motor head portion 34 is provided with a bearing 41 as a bearing that is press-fitted and rotatably supported by a rear end portion that is one end portion of the rotating shaft 11 of the motor 2 in the axial direction. A thrust spring 43 for applying a preload to the bearing 41 is accommodated in the rear part of the bearing 41.

  Each brush portion mounting hole 24 is provided through the body frame 31 in the central axis direction.

  On the other hand, the frame 32 includes a frame main body 45 formed in a longitudinal shape, and screwing portions 46 provided integrally at both ends of the frame main body 45.

  The frame main body 45 is formed with a mounting recess 47 in the center, and is inclined from the mounting recess 47 to the screwing portions 46 at both ends and opposite to the protruding direction of the mounting recess 47. The frame main body 45 is formed with a pair of rectifying plate screw retaining holes 48 and 48 for screwing the rectifying plate 4 around the mounting recess 47.

  The mounting recess 47 has a bearing 53 that is rotatably supported by press-fitting a front end portion that is the other end portion in the axial direction of the rotating shaft 11 of the motor 2, and an outer peripheral portion of the mounting recess 47. Is inserted. A projecting hole 54 through which the rotating shaft 11 projects forward is formed in the center of the bottom of the mounting recess 47.

  Screws 56 (only one is shown) are inserted through the current plate screwing holes 48 and 48.

  Each screwing portion 46 has a pair of screw holes 58, 58. A screw 59 (only one is shown) is inserted through these screw holes 58, 58, and this screw 59 is screwed and fixed to a screw fixing hole 61 formed in the flange portion 36 of the body frame 31.

  The rectifying plate 4 is also called a diffuser and rectifies the air blown from the centrifugal fan 5 to flow to the motor 2 side. The rectifying plate 4 is located between the motor 2 and the centrifugal fan 5 and It is attached to close the front end. The rectifying plate 4 includes a disc-shaped rectifying plate main body 63 and a plurality of front blades 64 and rear blades 65 as fixed wings protruding from the rectifying plate main body 63.

  The rectifying plate main body 63 is provided coaxially with the central axis of the main body case 3, and a concave portion 67 protruding toward the motor 2 is provided at the central portion. An insertion hole 68 through which the screw 56 is inserted is formed, and a screw hole 69 through which the screw 56 is screwed is formed around the insertion hole 68.

  The front blade 64 protrudes from the rectifying plate main body 63 to the front side, and is provided on the outer peripheral edge of the rectifying plate main body 63 in a plane spiral shape toward the outer peripheral direction, and is separated from each other in the circumferential direction of the rectifying plate main body 63 Has been. For this reason, between the front blades 64, a front guide air passage 71 that is continuous with the outer periphery of the current plate main body 63 is defined. The front guide air passage 71 guides the air blown out from the centrifugal fan 5 in a spiral manner from the rotating shaft 11 side to the outer peripheral direction. Further, the front blades 64 are located outside the outer periphery of the centrifugal fan 5 and face the outer periphery of the centrifugal fan 5.

  The rear blade 65 protrudes from the current plate main body 63 to the rear side, and is provided in a plane spiral shape in the opposite direction to the front blade 64 so as to go from the center side to the outer peripheral direction. Are spaced apart from each other in the direction. For this reason, a rear guide air passage 73 is formed between the rear blades 65 so as to be continuous with the outer peripheral portion of the current plate main body 63. The rear guide air passage 73 communicates with the front guide air passage 71 at the outer peripheral edge of the rectifying plate main body 63, and the suction air guided in the outer peripheral direction by the front guide air passage 71 is used as the rear of the rectifying plate 4. The guide is spirally guided to the rotating shaft 11 side.

  Further, the front guide air passage 71 and the rear guide air passage 73 communicate with each other through a communication notch (not shown) formed in the outer peripheral edge of the rectifying plate 4.

  The centrifugal fan 5 rotates integrally with the rotating shaft 11 of the motor 2 and has a rear shroud 75 as a plate portion provided in a disk shape, and a front shroud as a plate portion located in front of the rear shroud 75. 76 and a fan blade 77 as a blade portion integrally provided between the shrouds 75 and 76.

  The rear shroud 75 is formed with a fitting insertion hole 81 into which the rotating shaft 11 of the motor 2 is fitted. Further, the rear shroud 75 is sandwiched forward and backward by an annular rear fan washer 83 and a front fan washer 84 through which the rotary shaft 11 is inserted. The front fan washer 84 is fixed to the front end side of the rotating shaft 11 by a nut 85.

  On the other hand, the front shroud 76 is provided with a ventilation hole 87 as a round hole-like suction port in the center, and is formed in an inclined shape around the ventilation hole 87 so that the diameter is reduced from the rear shroud 75 side. Thus, a projecting portion 88 projecting forward is continuously formed.

  The fan blades 77 are provided in a plane spiral shape in a direction opposite to the front blade 64 of the rectifying plate 4 so as to extend from the vicinity of the peripheral edge of the ventilation hole 87 toward the outer periphery of the centrifugal fan 5 in plan view. It is formed in a wall shape that defines 89. These intake air passages 89 communicate with the front guide air passage 71 of the rectifying plate 4.

  The fan cover 6 includes a cover body 91 having a circular shape in plan view that substantially corresponds to the outer diameter of the centrifugal fan 5, a frame portion 92 formed in a frame shape on the outer peripheral edge of the cover body 91, and the frame A fitting portion 93 projecting from the outer peripheral edge of the portion 92 to the rear side.

  A round hole-like suction port 95 is formed in the center of the cover body 91, and is inclined from the periphery of the suction port 95 toward the outer periphery in correspondence with the shape of the front shroud 76 of the centrifugal fan 5. Is formed. In addition, an annular seal member that slidably contacts the projecting portion 88 of the ventilation hole 87 of the centrifugal fan 5 and connects the ventilation hole 87 to the suction port 95 in an airtight manner on the outer peripheral edge of the suction port 95 on the rear surface of the cover body 91. 96 is installed.

  The seal member 96 is a member having low frictional resistance and slippery, and is formed of a member that is not easily worn or thermally deformed by friction, such as Gore-Tex (registered trademark), as shown in FIG. There is an inclined surface 96a at the outer peripheral edge on the rear end side (centrifugal fan 5 side), and the thickness is reduced from the center side to the outer peripheral side, that is, the outer thickness in the circumferential direction is thinner than the inner thickness. It is formed to become. Specifically, for example, the rear corner portion of the outer side of the seal member 96 is cut into an inclined shape so as to be thinner than the inner side. Further, the seal member 96 is cut by sliding the tip of the projecting portion 88 of the centrifugal fan 5 so that a cut recess 96b is formed at the rear portion. Therefore, in the state where the cutting recess 96b is formed, the seal member 96 is formed such that the outer side in the circumferential direction is thinner than the inner side in the portion excluding the cutting recess 96b.

  The inclined surface 96a is formed at an inclination angle substantially orthogonal to the inclination angle of the protrusion 88 of the ventilation hole 87. For this reason, the projecting portion 88 of the ventilation hole 87 is configured to come into contact with the inclined surface 96a substantially perpendicularly.

  The cutting recess 96b is formed in a part of the inclined surface 96a, and includes a front sliding contact surface 96c in which the tip of the protruding portion 88 is in sliding contact and a side sliding contact surface 96d in which the outer surface of the protruding portion 88 is in sliding contact. Have.

  The front sliding contact surface 96c is an annular plane that is substantially orthogonal to the axial direction of the seal member 96.

  Further, the side sliding surface 96d is a surface continuous to the inclined surface 96a side, and the area is suppressed by the inclined shape of the seal member 96.

  Further, returning to FIG. 2, the frame portion 92 is formed in a stepped shape on the rear side with respect to the outer peripheral edge portion of the cover body 91, and the front end portions of the respective front blades 64 of the rectifying plate 4 are welded to the inner side. .

  The fitting portion 93 is formed so as to face the outer peripheral surface of the current plate 4, and the rear end portion is fitted to the outer peripheral edge portion of the flange portion 36 of the body frame 31.

  Next, the operation of the above embodiment will be described.

  When assembling the electric blower 1, the motor 2 is accommodated in the body frame 31 of the main body case 3, and the carbon brush assemblies 15 and 15 are attached to the brush portion mounting holes 24 from the outside of the body frame 31. The frame 32 and the rectifying plate 4 are sequentially inserted on the front side of the rotating shaft 11, and the centrifugal fan 5 is attached to the rotating shaft 11 protruding to the front side of the rectifying plate 4 via the fan washers 83 and 84, and tightened with the nut 85. Fix it.

  Thereafter, the fan cover 6 having the sealing member 96 attached around the suction port 95 on the inner surface is fitted to the front end portion of the body frame 31 of the main body case 3, and the centrifugal fan 5 is rotated by the motor 2.

  Then, the projecting portion 88 of the centrifugal fan 5 rotates in contact with the inclined surface 96a of the seal member 96, and the inclined surface 96a is cut and the projecting portion 88 bites into the seal member 96 to form a cutting recess 96b. The ventilation hole 87 and the suction port 95 are airtightly connected.

  Then, when the motor 2 is driven by supplying power to the terminal 28 and the rotating shaft 11 rotates integrally with the centrifugal fan 5, the electric blower 1 is driven by the negative pressure generated by the rotation of the centrifugal fan 5. Air is sucked into the electric blower 1 from the suction port 95. The sucked air flows into the intake air passage 89 of the centrifugal fan 5 through the ventilation holes 87 and then blows out along the fan blades 77 toward the outer periphery of the centrifugal fan 5.

  The air blown out from the centrifugal fan 5 flows into the front guide air passage 71 of the rectifying plate 4 and is spirally guided along the front blade 64 from the central axis side to the outer peripheral direction on the front side of the rectifying plate 4. The

  At this time, the air blown from the centrifugal fan 5 is prevented from circulating to the ventilation hole 87 side by the seal member 96.

  Thereafter, the air flows into the rear guide air passage 73 from the outer peripheral portion of the rectifying plate 4 through a communication notch (not shown), and the rear surface side of the rectifying plate 4 is moved from the outer peripheral side toward the central axis along the rear blade 65. It is guided in a spiral shape to be hydrostatic, and flows into the main body case 3 from the opening 35 of the body frame 31 via both sides of the frame 32.

  The air that has flowed into the main body case 3 to the motor 2 side is blown to the stator 14 to cool the stator 14, and further to cool the carbon brush 25 of the carbon brush assembly 15, while cooling the electric blower 1 from the exhaust port 38. Exhausted to the outside.

  As described above, according to the above-described embodiment, by forming the outer side in the circumferential direction of the seal member 96 thinner than the inner side, the slanted protrusion of the front shroud 76 of the centrifugal fan 5 slidably contacting the seal member 96. The contact area between the portion 88 and the seal member 96, that is, the area of the side sliding contact surface 96d, can be reduced, and the sliding resistance between the centrifugal fan 5 and the seal member 96 can be reduced. However, since the sliding resistance does not increase even when inclined, the amount of protrusion of the protrusion 88 can be suppressed as compared with the conventional centrifugal fan in which the protrusion protrudes linearly along the axial direction. The total length in the axial direction can be suppressed.

  In particular, the inclined surface 96a is inclined so as to be substantially perpendicular to the inclination direction of the protruding portion 88, whereby the sliding resistance between the seal member 96 and the protruding portion 88 can be most suppressed, and the protruding portion of the centrifugal fan 5 can be suppressed. The pressure with which 88 is pressed against the inclined surface 96a can be secured, and the cutting efficiency of the seal member 96 is improved.

  In addition, since the sliding resistance between the projecting portion 88 and the seal member 96 can be suppressed, the centrifugal fan 5 can be smoothly rotated, and the electric blower 1 can have a high output, and the overall length can be suppressed. Miniaturization is possible.

  In the above embodiment, the inclination angle of the inclined surface 96a is appropriately set corresponding to the inclination angle of the protruding portion 88, and if the sliding resistance with the protruding portion 88 can be reduced, the inclination angle of the protruding portion 88 is set. However, it is not necessarily required to be substantially vertical.

  Moreover, the detail of the electric blower 1 is not limited to the said structure.

  Furthermore, the electric blower 1 can be applied to various things besides a vacuum cleaner and an industrial blower.

It is a longitudinal cross-sectional view which expands and shows the sliding contact part of the centrifugal fan and sealing member of the electric blower of one embodiment of this invention. It is a longitudinal cross-sectional view which shows an electric blower same as the above.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric blower 2 Motor 3 Body case 4 Current plate 5 Centrifugal fan 6 Fan cover
11 Rotation axis
76 Front shroud as plate
87 Ventilation hole as a suction port
88 Protrusion
96 Seal member

Claims (1)

A motor with a rotating shaft;
A substantially cylindrical main body case for housing the motor;
A centrifugal fan attached to one end side of the rotating shaft, having a plate portion having a projecting portion projecting in an inclined manner toward the center side of the suction port at the peripheral portion of the suction port while opening the suction port,
A fan cover that covers the centrifugal fan and is attached to the main body case;
An annular seal member that slidably contacts the protruding portion of the centrifugal fan and closes a gap between the peripheral edge of the suction port and the fan cover;
The electric blower characterized in that the sealing member is formed so that the outer side in the circumferential direction is thinner than the inner side.

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