JPH1193892A - Motor-driven air blower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent leakage of air to the air blowing fan side being the negative pressure side even under high pressure by putting one of a sealing plate in a noncontact condition from an inner ring in at least one of bearings. SOLUTION: When a motor part 5 is driven, an air blowing fan 8 installed on a shaft 6 of a rotor 3 rotates, and air sucked by this air blowing fan 8 passes through the inside of the air blowing fan 8, and is straightened by a guide blade 9, and changes the direction in an outer peripheral part inner wall of a fan cover 10 and a bracket 4 while recovering pressure, and is introduced to the motor part 5, and is exhausted from an exhaust port 1a of a motor frame 1 while cooling the motor part 5. When air exhausted from the air blowing fan 8 is exhausted from the exhaust port 1a, since an anti-air blowing fan side sealing plate 7f of a bearing 7A supported by a bearing housing 4a contacts with an inner ring 7a, high pressure air does not pass through the inside the bearing 7A to the air blowing fan 8 side being the negative pressure side. Therefore, leakage of the air can be prevented, and high air blowing efficiency can be obtained.

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 FIG. 7 is a sectional view showing a main part of a conventional electric blower disclosed in, for example, Japanese Utility Model Publication No. 3-38479, and FIG. 8 is a sectional view. In the drawing, reference numeral 1 denotes a metal case main body having a substantially bottomed cylindrical shape and having an annular flat portion 1d integrally provided at one opening edge. A metal case end plate 13 is attached to one end opening side of the case main body 1, and a motor case 14 is formed by the case main body 1 and the case end plate 13. A bearing 1 is provided at the center of the bottom wall of the case body 1.
The bearing housing 16 which houses 5 is integrally provided. A bearing housing 18 having a built-in bearing 17 is also provided integrally at the center of the case end plate 13. A rotor 20 is accommodated in the motor case 14 with the rotor shaft 19 supported by bearings 15 and 17, and a stator 21 is accommodated surrounding the rotor 20.

[0003] A dust-proof disk 23 is attached to the rotor shaft 19 to cover an opening of the bearing housing 18 facing the case body 1, and is sandwiched between a retaining ring 24 and an inner ring 17 a of the bearing 17. It is adapted to rotate with the rotor shaft 19. An annular convex cover 25 is provided on the peripheral edge side of the dust-proof disc 23, and the convex cover 25 is bent over the entire annular convex portion 22 of the case end face plate 13 along the annular convex portion 22. A subtle gap g is formed between the annular convex portion 22 and the annular convex portion 22.

A commutator 26 is attached to the rotor shaft 19, and a centrifugal fan 2 is provided at an end of the rotor shaft 19 which penetrates the bearing 17 and the bearing housing 18.
7 is attached by a nut 28, and between the fan 27 and the case end plate 13, a rectifying plate 29 is provided which is screwed to the case end plate 13 or the like. 30 is the inlet 3
0a at the center of the fan cover.
And a fitting tubular portion 31 that covers the flow straightening plate 29 and continues to the annular flat portion 12. 34 is a brush device.

When the electric blower is driven in this state, the dust-proof disk 23 and the fan 2 are rotated together with the rotor shaft 19 of the rotor 20.
7, rotation of the intake port 30a,
It is possible to obtain a blowing action through the ventilation hole formed by the fan 27, the current plate 29, the inner edge of the annular flat portion 1 d and the side edge of the case end plate 13, the air passage 32 in the case and the exhaust hole 33. Further, the dust-proof disk 23 rotated together with the rotor shaft 19
Is provided so as to cover the opening of the bearing housing 18, and the annular convex portion cover 25 of the dust-proof disk 23 covers the annular convex portion 22, thereby providing dust protection for the bearing 17.

FIG. 9 is a sectional view of a main part showing another conventional dustproof bearing. In the figure, 40 is an inner ring, 41 is an outer ring, 42 is a ball, 43 is a ball retainer, 44 is grease, and 45 is a seal plate in which a metal reinforcing plate 45a is covered with a soft material 45b. Since the seal plates 45 are provided on both surfaces of the bearing, and both the seal plates 45 are provided in contact with the inner ring 40, a dustproof effect of the bearing is achieved.

[0007]

According to the conventional electric blower constructed as described above, the dust-proof disk 23 must be structured to cover the annular convex portion 22 of the case end plate 13.
Inevitably, the outer diameter increases and the imbalance of the rotor 20 increases, which causes vibration and noise to increase. In addition, since it is a press-formed product, the dustproof effect has been varied due to variations in dimensions.

Further, under high pressure, the fan 27
Since the pressure on the side is negative, air flows into the bearing 17 and dust enters, and the lubricant (grease etc.) inside the bearing 17 flows out to the outside together with the air flow. Was causing a decline.

Further, in the case of the conventional dustproof bearing shown in FIG. 9, although the dustproof effect can be achieved without using a dustproof disk, the seal plates 45 provided on both sides of the bearing are in contact with the inner ring 40 of the bearing. As a result, the load at the time of rotation increases due to the contact resistance of the contact portion, causing a decrease in performance.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and achieves high air-blowing efficiency by preventing air from leaking to a blower fan side which is a negative pressure side even under high pressure. It is an object of the present invention to provide an electric blower that can prevent dust from entering the inside of a bearing and can extend the life of the bearing.

[0011]

In an electric blower according to the present invention, a first bearing housing is formed at a center portion of a bottom surface, and a motor frame including motor parts such as a stator, a rotor, and a commutator is provided. A bracket provided on one end opening side of the motor frame and having a second bearing housing formed in a central portion, and provided on both ends of a shaft of the rotor, respectively supported by the first and second bearing housings; First and second bearings each having an outer ring, an inner ring, a ball disposed between the outer ring and the inner ring, and two seal plates for covering the upper and lower portions of the outer ring and the inner ring; and a rotation fixed to a shaft of the rotor. A blower fan that rotates together with the fan, a guide blade that guides air sucked from the blower fan to a motor unit, a fan cover that covers the blower fan and the guide blade, and is press-fitted and fixed to the bracket. In those and the first and second
At least one of the bearings has one of the seal plates disposed in non-contact with the inner ring of the bearing.

Further, the first frame supported on the motor frame side
One of the seal plates of the bearing is brought into contact with the inner ring and the other is kept out of contact with the inner ring, and a seal plate in contact with the inner ring is provided on the commutator side.

Further, one of the seal plates of the second bearing supported on the bracket side is brought into contact with the inner ring and the other is kept out of contact with the inner ring, and the seal plate in contact with the inner ring is provided on the side of the counter blower fan. Things.

Further, one of the seal plates of the first and second bearings is brought into contact with the inner ring and the other is kept out of contact with the inner ring, and the seal plate in contact with the inner ring is provided on the commutator side in the first bearing. In addition, the second bearing is provided on the side opposite to the blower fan.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. FIG. 1 is a sectional view of an electric blower according to Embodiment 1 of the present invention, FIG. 2 is an enlarged view of a main part thereof, and FIG. 3 is a sectional view of a bearing. In the drawing, reference numeral 1 denotes a motor frame having an exhaust port 1a on a side surface and a bearing housing 1b (first bearing housing) at a central portion, and has a bottomed cylindrical shape with one end opened. The motor frame 1 contains a stator 2, a rotor 3, a commutator 12, and the like. Reference numeral 4 denotes a bracket that is fixed to the opening side of the motor frame 1 and has a bearing housing 4a (second bearing housing) at the center and a ventilation port 4b around the bearing housing 4a. Axis of child 3, 7
A is a bearing on the bracket 4 side (second bearing), 7B is a bearing on the motor frame 1 side (first bearing), and is a bearing 7A.
And 7B are provided at both ends of the shaft 6, and the bearing housing 1
b, 4a. 7a is a bearing 7A,
7B, which rotates with the shaft 6. 7b is a bearing 7
A and 7B outer rings, 7c is a ball provided between the inner ring 7a and the outer ring 7b, 7d is a ball retainer, 7e is grease, 7f and 7g are seal plates covering the upper and lower openings of the inner ring 7a and the outer ring 7b. is there. The seal plate 7f on the side of the bearing 7A opposite to the blower fan is formed by covering a metal reinforcing plate 7h with a soft material 7i. The seal plate 7f is provided so as to contact the inner ring 7a. Reference numeral 8 denotes a blower fan fixed to the shaft 6 of the rotor 3 and rotates together with the rotor 3, 9 denotes guide vanes for guiding the air sucked from the blower fan 8 to the motor unit 5,
Numeral 10 covers the blower fan 8 and the guide vanes 9 and the bracket 4
The fan cover is press-fitted and fixed to the fan cover.

In the electric blower constructed as described above, when the motor section 5 is driven, the blower fan 8 attached to the shaft 6 of the rotor 3 rotates, and the air sucked from the blower fan 8 is shown in FIG. Blower fan 8 as shown by the arrow
Of the motor frame 1 while being rectified by the guide blades 9 and recovering the pressure, turning the fan cover 10 and the inner peripheral wall of the bracket 4 to be guided to the motor unit 5 and cooling the motor unit 5 to exhaust the motor frame 1. It is discharged from the mouth 1a.

According to the present embodiment, when the air discharged from the blower fan 8 is discharged from the exhaust port 1a, the seal plate 7f on the side opposite to the blower fan of the bearing 7A supported by the bearing housing 4a is connected to the inner race 7a. Because of the contact, high-pressure air does not pass through the inside of the bearing 7A to the blower fan 8 side, which is the negative pressure side, so that air leakage can be prevented and high blow efficiency can be obtained.

The seal plate 7f can prevent dust from entering the inside of the bearing 7A and also prevent the grease 7e in the bearing 7A from flowing out to the blower fan 8, so that the life of the bearing can be extended. .

As shown in FIG. 3, the internal structure of the bearing in this embodiment is such that a sealing plate 7f in which a metal auxiliary plate 7h is covered with a soft material 7i is fitted in a groove 7j provided in an inner ring 7a. It is established. Normally, the bearing is used by applying a preload by a preload spring. In the present embodiment in which the surface of the seal plate 7f in contact with the inner ring 7a is directed toward the counter blower fan, the inner ring 7a is given a preload by applying the preload. In this case, the contact between the seal plate 7f and the inner ring 7a at the contact point C increases.

FIG. 3 shows a configuration in which the groove 7j is provided at the location C where the seal plate 7f of the inner race 7a contacts, but as shown in FIG. 4, the location C where the seal plate 7f of the inner race 7a contacts is flat. The above-described effects can be obtained even with a simple structure.

Embodiment 2 FIG. FIG. 5 is a cross-sectional view of a main part of an electric blower according to Embodiment 2 of the present invention. In the drawing, 1 is a motor frame having a bearing housing 1b,
11 is a brush device attached to the motor frame 1, 11
a is a carbon brush, 12 is a commutator provided on the shaft 6 of the rotor 3, 7B is a bearing provided on the end face of the shaft 6 of the rotor 2, and supported by the bearing housing 1b. A seal plate 7f in contact with the inner ring 7a is provided.

In the electric blower constructed as described above, a part of the air guided to the motor part 5 is directly from the exhaust port 1a and a part is the end face of the motor frame 1, as indicated by the arrow in the drawing. After colliding from 1c and turning at the end face 1c, the gas is discharged from the exhaust port 1a of the motor frame 1.

According to the present embodiment, when the abrasion powder of the carbon brush 11a worn by the rotation of the commutator 12 collides with the end face 1c of the motor frame 1 together with the airflow and turns, the powder is directed toward the commutator 12 side. Seal plate 7f of bearing 7B
Is in contact with the inner ring 7a, so that the carbon brush 11a
The abrasion powder and dust contained in the airflow can be prevented from entering the inside of the bearing 7B, the grease inside the bearing 7B can be prevented from deteriorating due to the invading matter, and the life of the bearing can be extended.

Embodiment 3 FIG. FIG. 6 is a sectional view of an electric blower according to Embodiment 3 of the present invention. In the figure, the same or corresponding parts as those in the first or second embodiment are denoted by the same reference numerals, and the description is omitted. In the figure, reference numeral 7A denotes a bearing on the bracket 4 side, and 7B denotes a bearing on the motor frame 1 side. The bearings are provided at both ends of the shaft 6 of the rotor 3 and are supported by bearing housings 1b and 4a, respectively. 7f is a bearing 7A
, 7B, the seal plate 7f of the bearing 7A is arranged on the side of the counter blower fan, and the seal plate 7f of the bearing 7B is arranged on the side of the commutator 11a.

According to the electric blower constructed as described above, when the motor section 5 is driven, the blower fan 8 attached to the shaft 6 of the rotor 3 rotates, and the air sucked from the blower fan 8 is As shown by arrows, the inner wall of the fan cover 10 and the outer peripheral portion of the blanket 4 are turned to
While being guided inside and cooling the motor unit 5, a part directly collides with the end face 1c of the motor frame 1 and a part collides with the end face 1c of the motor frame 1 and turns at the end face 1c to be turned.
is discharged from a.

According to the present embodiment, when the air sucked from the blower fan 8 is exhausted from the exhaust port 1a while recovering the pressure, the air blown from the bearing 7A supported by the bearing housing 4a of the bracket 4 when the air is exhausted from the exhaust port 1a. On the fan side, the inner ring 7a and the seal plate 7f are in contact with each other, and the high-pressure air does not pass through the inside of the bearing 7A to the blower fan 8 side, which is the negative pressure side. High blowing effect can be obtained. In addition, since it is possible to prevent dust from entering the inside of the bearing 7A and prevent the grease 7e in the bearing 7A from flowing out to the blower fan 8, the life of the bearing can be extended.

Also, when abrasion powder of the carbon brush 11a, which is worn by rotation of the commutator 12, collides with the end face 1c of the motor frame 1 together with the airflow and turns, the seal plate 7f of the bearing 7B directed to the commutator 12 side. Is in contact with the inner ring 7a, so that abrasion powder of the carbon brush 11a and dust contained in the airflow do not enter the inside of the bearing, thereby preventing deterioration of grease inside the bearing due to invading objects and extending the life of the bearing. Can be.

[0028]

In the electric blower according to the present invention,
Since at least one of the first and second bearings is not in contact with the inner ring, the load at the time of rotation of the inner ring interlocking with the rotor can be reduced, and the blowing efficiency can be improved.

Further, since the seal plate on the commutator side of the bearing on the motor frame side is brought into contact with the inner race, the abrasion powder of the carbon brush, which is worn by the rotation of the commutator, collides with the end face of the motor frame together with the airflow and turns. In this case, since the abrasion powder of the carbon brush and dust contained in the airflow do not enter the inside of the bearing, deterioration of grease inside the bearing due to the invading matter is prevented, and the life of the bearing can be extended.

Also, since the seal plate on the side of the bracket side opposite to the blower fan that is in contact with the inner ring is in contact with the inner ring, the air with increased pressure does not pass through the inside of the bearing to the blower fan side that is the negative pressure side. Leakage of air can be prevented, and high air blowing efficiency can be obtained. Further, it is possible to prevent dust from entering the inside of the bearing and prevent the grease inside the bearing from flowing out to the blower fan side, so that the life of the bearing can be extended.

Since the seal plate on the side of the bracket on the side opposite to the blower fan of the bearing on the bracket side and the seal plate on the side of the commutator of the bearing on the side of the motor frame are brought into contact with the inner ring, the air having increased pressure is directed to the blower fan side on the negative pressure side. Since it does not pass through the inside of the bearing, air leakage can be prevented and high air blowing efficiency can be obtained,
Dust and the like can be prevented from entering the inside of the bearing, and grease inside the bearing can be prevented from flowing out to the blower fan side.
Further, since abrasion powder of the carbon brush and dust contained in the airflow do not enter the inside of the bearing, deterioration of the grease inside the bearing due to the invading matter is prevented, and the life of the bearing can be reliably extended.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an electric blower showing a first embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is an enlarged sectional view of a bearing.

FIG. 4 is an enlarged sectional view of a bearing.

FIG. 5 is an enlarged cross-sectional view of a main part of an electric blower according to a second embodiment of the present invention.

FIG. 6 is a cross-sectional view of an electric blower showing a third embodiment of the present invention.

FIG. 7 is a sectional view of a main part showing a conventional electric blower.

FIG. 8 is a sectional view showing a conventional electric blower.

FIG. 9 is an enlarged sectional view showing a conventional dustproof bearing.

[Description of Signs] 1 motor frame, 1b bearing housing, 2 stators, 3 rotors, 4 brackets, 4a bearing housing, 5 motor units, 6 shafts, 7A bearing, 7B bearing, 7a inner ring, 7b outer ring, 7c ball, 7d
Ball retainer, 7e grease, 7f seal plate, 7g
Seal plate, 8 blower fan, 9 guide blade, 10 fan cover, 11a carbon brush, 12 commutator.

Claims (4)

[Claims] A first bearing housing formed at a central portion of a bottom surface, a motor frame including a motor portion such as a stator, a rotor and a commutator; and a motor frame provided at one end opening side of the motor frame. And a bracket formed with a second bearing housing, and provided at both ends of a shaft of the rotor, respectively supported by the first and second bearing housings, and disposed between an outer ring and an inner ring, and between the outer ring and the inner ring. First and second bearings having a separated ball, two seal plates for covering the top and bottom of the outer ring and the inner ring, a blower fan fixed to a shaft of the rotor and rotating together with the rotor, and suction from the blower fan. And a guide blade for guiding the blown air to the motor unit, and a fan cover that covers the blower fan and the guide blade and is press-fitted and fixed to the bracket. At least one of the electric blowers is characterized in that one of the seal plates is arranged in non-contact with the inner ring of the bearing. 2. The seal plate of the first bearing supported on the motor frame side is brought into contact with the inner race, the other is kept out of contact with the inner race, and the seal plate in contact with the inner race is provided on the commutator side. The electric blower according to claim 1, wherein: 3. The seal plate of the second bearing supported on the bracket side is brought into contact with the inner ring and the other is kept out of contact with the inner ring, and the seal plate in contact with the inner ring is provided on the side of the counter blower fan. The electric blower according to claim 1, wherein: 4. The seal plate of the first and second bearings is configured such that one of the seal plates is in contact with the inner race and the other is not in contact with the inner race, and the seal plate in contact with the inner race is a commutator side in the first bearing. 2. The electric blower according to claim 1, wherein the second bearing is provided on a side opposite to the blower fan.