JP3346874B2 - Electric blower and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric blower used for a vacuum cleaner or the like.

[0002]

2. Description of the Related Art An electric blower of this type is disclosed in
The structures described in Japanese Patent Publication No. 21680 and Japanese Patent Publication No. 5-43880 are known.

[0003] In Fig. 6, reference numeral 1 denotes an electric blower main body, which comprises a drive motor unit 2 and a blower unit 3, both of which are brackets 4 formed by pressing a sheet metal material into a substantially disk shape.
Are classified by The drive motor unit 2 includes a stator 5 having a field coil wound around a stator core, and a rotor 6 having a coil wound around a rotating core which is rotatably fitted within the stator 5.
It consists of. The lower end of the rotating shaft 7 attached to the rotor 6 has a lower bearing holding recess formed in the center of the bottom of a frame 8 formed by pressing a sheet metal material constituting a part of the main body 1 into a bottomed cylindrical shape. It is rotatably supported by a lower bearing 10 held by the section 9. A commutator 11 is provided in the vicinity of the lower end of the rotating shaft 7, and the brush 1 held on the commutator 11 by brush holding portions 12 provided on both sides of the frame 8.
3 is urged by a spring and is in contact therewith.

The bracket 4 is attached to an opening on the upper surface of the frame 8, and an upper bearing holding portion 14 is provided in an inverted concave shape at the center thereof to fit and hold an upper bearing 15. Rotating shaft 7
Is rotatably supported by the upper bearing 15 and penetrates the bracket 4. Reference numeral 16 denotes an exhaust hole formed on a side surface of the frame 8. Reference numeral 17 denotes a ventilation hole formed around the upper bearing holding portion 14 of the bracket 4, and communicates the drive motor 2 and the blower 3. Reference numeral 18 denotes a fan casing having a suction port 19 at the center of the upper surface, the outer peripheral edge of which is fitted and fixed to the outer peripheral edge of the upper surface of the bracket 4. 20
Is a blower fan fitted and fixed to the upper end of the rotary shaft 7 in the fan casing 18, and 21 is a fixed fan formed of a plastic material, which rectifies a high-speed airflow generated by the blower fan 20 to open the ventilation hole 17. And is fixed to the bracket 4 at a position below the blower fan 4.

In FIG. 7, reference numeral 22 denotes an upper bearing holding portion 1 around a root of the upper bearing holding portion 14 of the bracket 4.
4 is an annular upper reinforcing step formed so as to project concentrically to the drive motor unit 2 side in a ∪-shaped cross section. Reference numeral 23 denotes an annular lower reinforcing step formed so as to protrude concentrically with the lower bearing holding portion 9 around the root portion of the lower bearing holding portion 9 in the frame 8 and projecting in a reverse 断面 -shaped cross section toward the drive electric unit 2. .

FIG. 8 shows a general configuration of a general bracket 4 and a frame 8 and an elastic holder 24 for holding the electric blower main body 1 in, for example, the main body of the electric vacuum cleaner. FIG. The ventilation holes 17 are divided right and left by a bridge 25 including the upper bearing holding portion 14. Reference numeral 26 denotes a holding hole formed to face left and right with the lower bearing holding portion 9 as a center, and press-fits and holds a convex portion 27 provided on the holder 24.

When power is supplied to the conventional electric blower main body 1, the rotating shaft 7 having both ends supported by the upper and lower bearings 15 and 10 rotates, and the blower fan 20 also rotates. Is sucked through the suction port 19 of
The air is rectified by the fixing fan 21 and is discharged from the exhaust hole 16 while cooling the drive motor unit 2 through the ventilation hole 17. At this time, the number of rotations is, for example, about 38,000 in the case of a vacuum cleaner that requires a high degree of vacuum to suck dust.
High speed rotation of about r / min. In order to maintain the high-speed rotation, the upper and lower bearing holding portions 1 are so arranged that the upper and lower bearings 15 and 10 do not rotate with respect to the bracket 4 or the frame 8.
4 and 9 must be securely held by frictional resistance. The dimensional relationship for obtaining this frictional resistance is based on the experimental results, and the inner diameter of the upper and lower bearing holding parts 14 and 9 is φ22
mm, the tolerance is + 0.013-0mm,
The outer diameter of the lower bearings 15 and 10 is φ22 mm and the tolerance is 0 to −−.
0.009 mm.

By the way, a bracket 4 as shown in FIG.
In the press working process, first, the upper bearing holding portion 14 having an inverted concave cross section is formed by drawing. At this time, a tensile residual stress is generated inside the sheet metal material from the outer periphery toward the center, that is, toward the upper bearing holding portion 14, but the appearance is balanced. Next, when the ventilation holes 17 are formed by punching, the tensile residual stress of the sheet metal material is reduced by the bridge 2.
The balance is lost between the fifth part and the ventilation hole 17. For this reason, the material between the upper bearing holding portion 14 and the ventilation hole 17 contracts by losing the tensile residual stress toward the center, and deforms the upper bearing holding portion 14 to a predetermined dimensional tolerance or less, thereby forming an elliptical shape. .

For this reason, in the drawing process of the upper bearing holding portion 14, the upper bearing holding portion 14 is formed into an elliptical shape larger than a specified size in consideration of a deformation dimension generated by punching in advance, so that the ventilation hole 17 is formed. A processing method is adopted in which the upper bearing holding portion 14 becomes a perfect circle when punching is performed.

When the holding hole 26 is formed outside the lower bearing holding portion 9 of the frame 8, the balance of the tensile residual stress working toward the lower bearing holding portion 9 is lost.
Since the shape of the lower bearing holding portion 9 becomes elliptical as it is, a processing method equivalent to that of the bracket 4 is employed.

[0011]

In the above-described conventional electric blower, a processing method is used in which deformation due to tensile stress during press working of the bracket 4 and the frame 8 is taken into account, and in particular, each bearing holding portion. In addition, it is difficult to secure the dimensions of the sheet metal, and it is necessary to prepare several types of punches having different dimensions for changes in the sheet thickness of the sheet metal material, and to perform very troublesome work such as dealing with each lot. Was. In addition, since it is difficult for the bearing holding portion to have a perfect circular shape as the final finished shape, the bearing is not held in close contact with the bearing holding portion over the entire circumference, and the bearing itself rotates in the holding portion and vibration due to rattling. And the occurrence of abnormal sounds.

Further, reinforcing step portions 22 and 23 each having a cross section formed at the base of the upper and lower bearing holding portions 14 and 9 and having an inverted U shape are provided.
Are formed so as to protrude toward the drive motor unit 2, the insulation distances t1 and t2 between the rotor 6 and the commutator 11 and the upper and lower reinforcing step portions 22 and 23 are reduced, which is an electrical hazard. When the required insulation distance is secured, the electric blower main body 1 is disadvantageously enlarged in the direction of the rotating shaft 7.

The present invention has been made to solve the above-mentioned problems, and a first object of the present invention is to prevent deformation of an upper bearing holding portion due to a change in residual tensile stress generated by press working. Thus, an electric blower capable of extending the life of the upper bearing and reducing the size of the main body is obtained. Also,
A second object is to provide an electric blower in which deformation of an upper bearing holding portion due to a change in residual tensile stress caused by press working is more reliably prevented.

A third object of the present invention is to provide an electric blower capable of prolonging the life of the lower bearing and reducing the size of the main body by preventing deformation of the lower bearing holding portion due to a change in residual tensile stress generated by press working. What you get. A fourth object is to prevent deformation of the upper and lower bearing holding portions due to a change in residual tensile stress generated by press working, thereby increasing the life of the upper and lower bearings and reducing the size of the main body. Obtain a blower.

[0015]

An electric blower according to the present invention is formed by press working having an inverted concave upper bearing holding portion for holding an upper bearing at the center and a ventilation hole around the upper bearing holding portion. A bracket, a fan casing mounted on the upper surface of the bracket to cover the blower fan and the fixing fan, and a bottomed bottom having a concave lower bearing holding portion fixed to the bracket and holding a lower bearing on the bottom surface. A cylindrical frame, an upper end of which is directly connected to the blower fan through the upper bearing, and a lower end is provided with a rotating shaft, a rotor, and a drive motor unit having a stator, each of which is supported by the lower bearing; A reinforcing step formed by pressing to protrude toward the non-rotor is provided between the upper bearing holding portion of the bracket and the ventilation hole.

The reinforcing step is formed concentrically with the upper bearing holding portion around the upper bearing holding portion.

Also, a bracket having an inverted concave upper bearing holding portion for holding the upper bearing at the center, a fan casing mounted on the upper surface side of the bracket so as to cover the blower fan and the fixing fan, A bottomed cylindrical frame formed by press working having a concave lower bearing holding portion fixed and holding the lower bearing on the bottom surface, a holding hole around the lower bearing holding portion, and an upper end penetrating the upper bearing. A rotating shaft directly connected to the blower fan and having a lower end supported by the lower bearing, a drive motor having a commutator, and a non-commutator side between the lower bearing holding portion and the holding hole. A reinforcing step formed by a protruding press working is provided.

Further, a bracket formed by press working having an inverted concave upper bearing holding portion for holding the upper bearing at the center and a ventilation hole around the upper bearing holding portion, and a blower fan on the upper surface side of the bracket And a fan casing mounted to cover the fixing fan, formed by pressing having a concave lower bearing holding portion fixed to the bracket and holding the lower bearing on the bottom surface, and a holding hole around the lower bearing holding portion. And a rotating shaft, a rotor, a stator, and a rectifier , the upper end of which is directly connected to the blower fan through the upper bearing and the lower end of which is supported by the lower bearing.
A drive motor unit having an armature, and a periphery of the upper bearing holding unit.
Surrounding the rotor, projecting to the opposite side to the rotor, and
Around the lifting unit, and the commutator in which the reinforcing step portion formed by press working to project on the opposite side are provided, respectively. Further, in the manufacturing method of the electric blower according to the present invention, the steps of forming a lower bearing holder for holding a bearing holder or the lower bearing part of maintaining upper bearing in each drawing, the non-rotor side or non A process of forming a reinforcing member on the commutator side by drawing, and a punching process of a ventilation hole formed around the upper bearing holding portion or a holding hole formed to face left and right around the lower bearing holding portion. And a step of forming the same.

[0019]

In the electric blower constructed as described above, the upper reinforcing step, which protrudes toward the upper surface of the bracket and is formed on the outer periphery of the upper bearing holding portion, prevents a change in tensile stress due to the formation of the ventilation hole. be able to. Therefore, the upper bearing holding portion does not change its shape, the upper bearing is securely held by the upper bearing holding portion, and the outer ring of the upper bearing does not rotate even if the rotating shaft rotates at high speed. , The rotating shaft can be smoothly rotated. In addition, the insulation distance between the upper reinforcing step and the rotor is sufficiently ensured. Even if the rotor is eccentrically rotated due to some abnormality, it does not become an electrically dangerous state.

Further, since the upper reinforcing step is formed concentrically with the upper bearing holding portion, it is possible to reliably prevent a change in tensile stress due to the formation of the ventilation hole.

Further, a lower reinforcing step projecting outward from the bottom surface of the frame and formed on the outer periphery of the lower bearing holding portion prevents a change in tensile stress caused by the formation of the holding hole. For this,
There is no change in the shape of the lower bearing holding part, the lower bearing is securely supported by the lower bearing holding part, and even if the rotating shaft rotates at high speed, the outer ring of the lower bearing does not rotate, Can be rotated smoothly. In addition, since the insulation distance between the lower reinforcing step and the commutator is sufficiently ensured, even if the commutator rotates eccentrically due to some abnormality, it does not become an electrically dangerous state.

Further, since the upper and lower reinforcing steps project from the side opposite to the drive motor, even if the rotor or commutator rotates eccentrically due to some abnormality,
A sufficient insulation distance from the lower reinforcing step is ensured.

[0023]

【Example】

Embodiment 1 FIG. Hereinafter, a first embodiment of the electric blower according to the present invention will be described with reference to FIGS. 1 is a vertical front view of an electric blower according to one embodiment of the present invention, FIG. 2 is an enlarged plan view of a bracket shown in FIG. 1, and FIG. 3 is a bottom view of a frame shown in FIG. In the drawings, the same or corresponding parts as those in FIGS. 6 to 8 are denoted by the same reference numerals, and detailed description thereof will be omitted.

Reference numeral 28 denotes a stepped part 2 formed by pressing a sheet metal material into a substantially disk shape and bent upward over the entire outer peripheral edge thereof.
9 is a bracket for forming the bracket 9. This bracket 28
Is a semi-circular vent 17 divided into two parts by a plurality of bridges 25 around the outer periphery of the upper bearing retainer 14, It is located between the upper bearing holding part 14, is concentric with the upper bearing holding part 14, has both ends extending to the respective bridges 25, and is formed in a semi-circular shape having an inverted U-shaped cross section formed to face each other. The upper reinforcement step portion 30 is formed in a shape.

Reference numeral 31 denotes a frame formed by pressing a sheet metal material into a cylindrical shape with a bottom, and an upper end opening is fixed to the bracket 28. The frame 31 has a plurality of holding holes 26 for press-fitting and holding the projections 27 of the holder 24 used when holding the lower bearing holding portion 9 and the electric blower main body 1 on the side surface, and the holding holes 26. Between the lower bearing holding portion 9 and the lower bearing holding portion 9, the lower bearing holding portion 9 is formed of an annular lower reinforcing step portion 32 having a 同 -shaped cross section formed concentrically. The frame 31 has a built-in electric drive unit 2 including a stator 5 and a rotor 6.

The blower 3 comprises a fan casing 18, a blower fan 20 fixed to the upper end of the rotating shaft 7, and a fixed fan 33 fixed to the upper surface of the bracket 28. Fixed fan 3
3. Arranged in the order of the blower fan 20, and a fan casing 18 is attached so as to cover these two fans. The central opening 34 of the fixed fan 33 is press-fitted on the outer periphery of the upper bearing holding portion 14, and the annular seal ring 35 formed on the outer periphery of the central opening 34 is
0 is pressed in the entire circumference with the upper surface of the bracket 0 to eliminate a gap with the bracket 28. For this reason, the outside air drawn into the blower 3 from the central opening of the fan casing 18 by the blower fan 20 enters the lower side from the outer periphery of the fixed fan 33, enters the frame 31 through the vent hole 17, and It is discharged from the exhaust hole 16. A blade (not shown) for sending the rectified outside air to the ventilation hole 17 is formed in a curved radial shape on the outer peripheral portion of the lower surface of the fixed fan 33.

Next, the bracket 28 and the frame 31
The general press working process will be described in the order of processes with reference to FIG. (1) Blanking each flat plate to a predetermined size. (A1, b1) (2) Each outer shape is formed by the first drawing. (A2, b2) (3) In the second drawing, the upper bearing holding portion 14 or the lower bearing holding portion 9 is formed in a perfect circle in accordance with the design dimensions. (A3, b3) (4) The upper reinforcement step 30 or the lower reinforcement step 32 is formed by the third drawing. (A4, b4) (5) The ventilation holes 17 or the holding holes 26 are respectively formed by punching. (A5, b5)

The shape of the upper bearing holding portion 14 is such that the contraction stress due to the change in the residual stress caused by the formation of the ventilation hole 17 is reduced by the upper reinforcing step portion 3.
0 protects, even if the upper bearing holding portion 14 is formed to be a perfect circle in advance, a predetermined dimension is secured without deformation, and the upper bearing 15 is attached to the upper bearing holding portion 14 of the bracket 28. When inserting and holding, the upper bearing 15 is securely held by the upper bearing holding portion 14. Also, in the lower bearing holding portion 9 of the frame 31, the lower reinforcing step portion 32 protects the contraction stress due to the change of the residual stress caused by the formation of the holding hole 26,
As described above, the lower bearing 10 is held in a true circular shape, and the lower bearing 10 is also securely held by the lower bearing holding portion 9.

In this state, even when the electric blower main body 1 is energized and the rotating shaft 7 rotates at a high speed of about 38,000 r / min, the outer rings of the upper bearing 15 and the lower bearing 10 are kept in the respective bearing holding portions. The rotation shaft 7 is smoothly rotated without being reliably held by the rotation shafts 14 and 9. In addition, since the upper reinforcing step 30 and the lower reinforcing step 32 are formed so as to protrude on the surfaces opposite to the drive electric unit 2, even if the rotating shaft 7 is eccentric and abnormally rotates, Electrically safe. Further, the height and shape of each of the upper reinforcing step 30 and the lower reinforcing step 32 can be formed relatively freely due to the strength of the residual tensile stress, since the drive electric section 2 is not located in the vicinity thereof. Further, since the seal ring 35 of the fixed fan 33 is pressed against the entire upper surface of the upper reinforcing step portion 30, the leakage airflow between the drive motor unit 2 and the blower unit 3 is cut off, and the blower efficiency is improved. Leads to.

Embodiment 2 FIG. FIG. 5 is an enlarged plan view of another embodiment of the bracket. In the figure, 30A is a semicircular vent hole 17 divided into two parts by a bridge 25 around the upper bearing holding portion 14 having an inverted concave shape at the center, and a bridge 25 around the outer periphery of the upper bearing holding portion 14; An upper reinforcing step formed in an annular shape concentrically with the upper bearing holding part 14 between the upper bearing holding part 14 and the upper bearing holding part 14.

The upper reinforcing step 30A has the same shape as the plurality of upper reinforcing steps 30 shown in the first embodiment.
Since the deformation of the upper bearing holding portion 14 due to the residual stress caused by the formation of the upper bearing holding portion 14 is prevented, the upper bearing holding portion 14 can be formed in a perfect circular shape in advance, and the processing becomes easier accordingly.

[0032]

Since the present invention is configured as described above, it has the following effects.

Since the upper reinforcing step is formed between the upper bearing holding portion and the ventilation hole so as to protrude toward the non-rotor , the upper bearing can be subjected to residual compressive stress generated by processing the sheet metal material. Since the deformation of the holding portion can be prevented, the machining itself is facilitated, and since the deformation of the upper bearing holding portion does not occur, the upper bearing is easily inserted, and the outer ring of the upper bearing is securely held. In addition, it contributes to extending the life of the bearing. Further, since the upper reinforcing step does not protrude toward the rotor, it is electrically safe.

Further, since the upper reinforcing step is formed concentrically with the upper bearing holding portion around the upper bearing holding portion, the change in the residual compressive stress caused by the formation of the ventilation holes and the bridges can be more reliably achieved. Can respond.

A non-commutator is provided between the lower bearing holding portion and the holding hole.
By forming the lower reinforcing step portion projecting to the side , the deformation of the lower bearing holding portion can be prevented from the residual compressive stress generated due to the processing of the sheet metal material, so that the processing itself becomes easy and the lower bearing Since the holding part does not deform,
Since the lower bearing is easily inserted and the outer ring of the lower bearing is securely held, the life of the bearing is prolonged. Further, since the lower reinforcing step does not protrude toward the commutator, it is electrically safe.

Since the upper reinforcing step is formed so as to protrude on the side opposite to the rotor and the lower reinforcing step is formed so as to protrude on the side opposite to the commutator, the rotor or the commutator may rotate eccentrically due to some abnormality. However, since the insulation distance between these and the upper and lower reinforcement steps is sufficiently ensured, while being electrically safe,
The size of the electric blower main body can be reduced.

[Brief description of the drawings]

FIG. 1 is a vertical sectional front view of an electric blower showing one embodiment of the present invention.

FIG. 2 is a plan view of a bracket of the electric blower.

FIG. 3 is a bottom view of a frame of the electric blower.

FIG. 4 is a view showing a schematic pressing process of a bracket and a frame of the electric blower.

FIG. 5 is a plan view of a bracket of an electric blower showing another embodiment of the present invention.

FIG. 6 is a vertical sectional front view showing a conventional electric blower.

FIG. 7 is a longitudinal sectional front view showing another conventional electric blower.

FIG. 8 is a main part configuration diagram showing another conventional electric blower.

[Explanation of symbols]

 2 Drive motor unit 3 Blower unit 7 Rotary shaft 9 Lower bearing holding unit 14 Upper bearing holding unit 17 Vent hole 25 Bridge 26 Holding hole 28 Bracket 30 Upper reinforcing step 31 Frame 32 Lower reinforcing step

Continuation of front page (56) References JP-A-4-183996 (JP, A) JP-A-51-108215 (JP, A) JP-A-5-207700 (JP, A) JP-A-4-80267 (JP) , U) Fully open sho 60-194191 (JP, U) Fully open sho 56-133998 (JP, U) Fully open sho 64-9466 (JP, U) Fully open sho 63-117274 (JP, U) (58) Field surveyed (Int.Cl. ⁷ , DB name) H02K 5/04-5/16 F04D 29/44 H02K 7/14 H02K 15/14 H02K 23/00

Claims (5)

(57) [Claims] 1. A bracket formed by press working having an inverted concave upper bearing holding portion for holding an upper bearing at the center, a ventilation hole around the upper bearing holding portion, and a blower fan on an upper surface side of the bracket. And a fan casing attached to cover the fixing fan, a bottomed cylindrical frame having a concave lower bearing holding portion fixed to the bracket and holding the lower bearing on the bottom surface, and an upper end penetrating the upper bearing. A driving motor unit having a rotating shaft, a rotor, and a stator directly connected to the blower fan and having a lower end supported by the lower bearing, between the upper bearing holding portion of the bracket and the ventilation hole. Non-rotating
An electric blower characterized by having a reinforcing step formed by press working protruding toward a child side. 2. The electric blower according to claim 1, wherein the reinforcing step portion is formed around the upper bearing holding portion so as to be concentric with the upper bearing holding portion. 3. A bracket having an inverted concave upper bearing holding portion for holding an upper bearing at the center, a fan casing mounted on the upper surface side of the bracket to cover the blower fan and the fixing fan, and A bottomed cylindrical frame formed by press working having a concave lower bearing holding portion fixed and holding the lower bearing on the bottom surface, a holding hole around the lower bearing holding portion, and an upper end penetrating the upper bearing. A rotating shaft directly connected to the blower fan and a lower end respectively supported by the lower bearing ; and a drive motor unit having a commutator, and a non-commutator side between the lower bearing holding unit and the holding hole. An electric blower comprising a reinforcing step formed by protruding press working. 4. A bracket formed by press working having an inverted concave upper bearing holding portion for holding an upper bearing at the center, a ventilation hole around the upper bearing holding portion, and a blower fan on the upper surface side of the bracket. And a fan casing mounted to cover the fixing fan, formed by pressing having a concave lower bearing holding portion fixed to the bracket and holding the lower bearing on the bottom surface, and a holding hole around the lower bearing holding portion. And a rotating shaft, a rotor, a stator, and a commutator whose upper end is directly connected to the blower fan through the upper bearing and whose lower end is respectively supported by the lower bearing.
And a drive electric unit that performs the rotation around the upper bearing holding unit, on the side opposite to the rotor.
Protruding around the lower bearing holding portion, opposite to the commutator.
Reinforcement step formed by press working protruding to the opposite side
An electric blower characterized by being provided respectively . 5. A step of forming an upper bearing holding portion for holding an upper bearing or a lower bearing holding portion for holding a lower bearing by drawing, and drawing a reinforcing member on a non -rotor side or a non-commutator side. And a step of forming through holes a hole formed around the upper bearing holding portion or a holding hole formed to face left and right with the lower bearing holding portion as the center. A method for manufacturing an electric blower, comprising: