JPH04164199A - Motor-driven blower - Google Patents

Abstract

PURPOSE:To improve the cooling effect by forming an air passage hole at the position close to the middle part between a motor frame and a diffuser. CONSTITUTION:The air drawn from the intake port 29 of a fan cover 28 by the high speed revolution of a centrifugal fan 17 is discharged in the radial direction from the outer peripheral part of the centrifugal fan 17, and passes through the outer peripheral part of a diffuser 23 and is discharged from the discharge port 30 of the fan cover. At this time, also the air in the part between the centrifugal fan 17 and the diffuser 23 is pushed out in the outer peripheral direction of the diffuser 23 by the high speed revolution of the centrifugal fan 17. While, the cooling air forming through the high speed revolution of a cooling fan 10 intrudes into a motor frame 4 from a cooling air inlet 11, and after cooling a driving part 9, the cooling air is discharged from a cooling air outlet 12, and a part of the cooling air is drawn between the centrifugal fan and the diffuser 23 through an air passage hole 25 by the high speed revolution of the centrifugal fan 17. Accordingly, the air quantity of the cooling air increases, and the cooling effect is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a so-called wet type electric blower capable of sucking air containing moisture.

(b) Conventional technology This type of wet type electric blower was developed, for example, in
As shown in Japanese Patent No. 352, a flow path for air containing dust and moisture and a flow path for cooling air that cools the motor are separate. Therefore, as shown in FIG. 3, for example, the conventional electric blower 40 has an exhaust port 30 on the side of the fan cover 28, so that the airflow discharged from the centrifugal fan 17 passes through the outer circumference of the diffuser 41. Exhaust port 30...
On the other hand, the cooling air that cools the drive unit 9 of the motor 2 is generated by the cooling fan 10 and
It enters the motor case 5 from the cooling air inlet 11 of the rear case 3, passes through the drive section 9 and is cooled, and then the rear case 3
The cooling air is discharged from the cooling air outlet 12, and the cooling air and the intake air are passed through the electric blower 40 separately. However, centrifugal fan 17,
The cooling fans 10 are attached to both the front and rear ends of the same rotating shaft 6, and therefore, in order to increase the amount of suction air containing dust and moisture, it is necessary to reduce the amount of cooling air. Therefore, as a measure to prevent the temperature of the motor 2 from rising, it is necessary to increase the size of the core of the rotor 7 and increase the stacking thickness of the core.
There are disadvantages that the 0 becomes large and the manufacturing cost becomes high.

(c) Problems to be Solved by the Invention The present invention provides a wet-type electric blower that can suck air containing moisture, and by improving the flow path of the cooling air, it can be used without increasing the load on the cooling fan. - The amount of air passing through the motor is increased, so that the temperature does not rise even if the motor is made smaller.

(d) Means for Solving the Problems In order to solve the above problems, the electric blower of the present invention has a drive unit housed in a motor case consisting of a motor frame and a rear case, and the front and rear of the rotating shaft are separated from the motor case. A protruding motor, a centrifugal fan fixed to the front rotating shaft of the motor, a diffuser disposed between the centrifugal fan and the motor frame, an intake port in the center, and a plurality of exhaust ports on the sides. a fan cover that covers the centrifugal fan and diffuser and is attached to the motor frame; a cooling fan fixed to the rear rotating shaft of the motor; and a cooling fan provided on the bottom and side surfaces of the rear case, respectively. The cooling fan has an air inlet and a cooling air outlet, and is characterized in that an air passage hole is provided near the center of the motor frame and the diffuser to guide a part of the cooling air from the cooling fan toward the centrifugal fan. .

(E) Effect With the above configuration, the centrifugal fan and the cooling fan rotate at high speed by the drive of the motor, and the high-speed rotation of the centrifugal fan causes the air sucked in from the intake port of the fan cover to be discharged in the radial direction from the outer periphery of the centrifugal fan. After that, the air passes through the outer circumference of the diffuser and is exhausted from the exhaust port of the fan cover.

At this time, the air between the centrifugal fan and the diffuser is also pushed out toward the outer circumference of the diffuser due to the high speed rotation of the centrifugal fan. On the other hand, the cooling air generated by the high-speed rotation of the cooling fan enters the motor frame from the cooling air inlet, cools the drive part, and then is discharged from the cooling air outlet.
A part of the cooling air is drawn between the centrifugal fan and the diffuser through the air passage holes due to the high speed rotation of the centrifugal fan, thereby increasing the volume of the cooling air and increasing the cooling effect.

(f) Example The following will explain the embodiments shown in FIGS. 1 and 2.

1 is a wet-type electric blower that can suck air containing dust and moisture, and is equipped with a motor 2 at the rear. The motor 2 includes a rear case 3 and a drive section 9 consisting of a rotor 7, a stator 8, etc. with a rotating shaft 6 mounted in a motor case 5, which is composed of a motor frame 4 that closes the front opening of the rear case 3. The front and rear of the rotating shaft 6 are arranged to protrude from the front and rear of the motor case 5. A rear rotating shaft 6a located behind the rotating shaft 6 protrudes rearward from the bottom surface 3a of the rear case 3, and has a cooling fan 10 mounted thereon. A cooling air inlet 11 is formed on the bottom surface 3a of the rear case 3 facing the cooling fan 10, and a cooling air outlet 12 is formed on the side surface 3b. It is supposed to pass through.

The motor frame 4 has a disc shape, and has a diffuser contact surface 15 in which a bearing holding cylinder 14 for holding a bearing 13 of the front rotating shaft 6b of the motor 2 is formed in the center, and an annular engagement surface formed in a brim shape at the peripheral edge. It has a combined outer circumferential surface 16.

Reference numeral 17 denotes a centrifugal fan that is attached to a front rotating shaft 6b located in front of the rotating shaft 6, and has a plurality of blades arranged in the radial direction.
and the rear side fixing plate 2o by caulking, and the caulking piece 21 is formed from the front side support plate 19 and the rear side fixing plate 20.
is somewhat prominent. The high-speed rotation of the centrifugal fan 17 sucks in air from the central opening 19a and exhausts air from the peripheral opening 22 in the radial direction.

23 is the diffuser contact surface 15 of the motor frame 4
The diffuser is a disc-shaped synthetic resin diffuser that is tightened and fixed with a tightening screw and disposed between the centrifugal fan 17 and the motor frame 4.

and the motor frame 4 and the diffuser 23
A space 2 is located near the center of the motor case 5 and between the diffuser 23 and the centrifugal fan 17.
4 is provided with an air passage hole 25 that communicates with the air passage hole 25. The air passage hole 25 is connected to a motor frame hole 26 and a diffuser center hole 27.
A part of the cooling air inside the motor case 5 is guided to the space 24 on the centrifugal fan 17 side. Further, the bearing holding cylinder 14 is inserted into the diffuser center hole 27.

A metal fan cover 28 is attached to the motor frame 4 to cover the centrifugal fan 17 and the diffuser 23, and has an intake port 29 in the center and a plurality of exhaust ports 30 at predetermined intervals on the circumferential side surface 28a. The rear engaging edge of the circumferential side surface 28a is press-fitted into the outer circumferential surface 16 and fixed.

Furthermore, an outer peripheral edge 31 is provided on the outer peripheral portion of the diffuser 23.
A plurality of guide vanes 32 are formed at intervals from each other, and the exhaust port 30 is surrounded by the adjacent guide vanes 32, the outer peripheral edge 31, and the peripheral side surface 28a of the fan cover 28.
A volume chamber 33 communicating with ' is formed.

When the electric blower 1 is driven, the centrifugal fan 17 and the cooling fan 10 rotate at high speed. The high-speed rotation of the centrifugal fan 17 sucks air containing dust and moisture through the intake port 29 of the fan cover 28, and exhausts the air from around the centrifugal fan 17 in a radial direction. The discharged suction air is converted from dynamic pressure to static pressure in a volume chamber 33 on the outer periphery of the diffuser 23, and then exhausted from the exhaust port 30. At this time, the air between the centrifugal fan 17 and the diffuser 23 is also pushed out toward the outer circumference of the diffuser 23 due to the high speed rotation of the centrifugal fan 17. On the other hand, the cooling air generated by the high-speed rotation of the cooling fan 10 enters the motor case 5 from the cooling air outlet 11, cools the drive unit 9, and is then discharged from the cooling air outlet]2. Due to the high-speed rotation of the centrifugal fan 17, the wind is sucked into the space 26 between the centrifugal fan 17 and the diffuser 23 through the air passage hole 25, and is guided to the centrifugal fan 17 side, and then is sent to the exhaust port 30 together with the intake air. This increases the amount of cooling air passing through the motor case 5, thereby increasing the cooling effect of the drive unit 9. Therefore, the cooling fan 10
Since the cooling effect inside the motor case 5 can be enhanced without increasing the load on the motor 2, the temperature rise in the drive section 9 can be reduced even if the motor 2 is downsized. An electric blower 1 can be obtained.

(G) Effects of the Invention The present invention is constructed as described above, and the cooling effect can be enhanced by increasing the amount of cooling air for the motor with a simple configuration of providing an air passage hole near the center of the motor frame and the diffuser. This makes it possible to obtain an electric blower that is small, lightweight, and inexpensive to manufacture.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view of an embodiment of the electric blower of the present invention;
Figure 2 is an exploded half-sectional view showing the arrangement of the main parts;
FIG. 3 is a partially cutaway side view of the prior art. DESCRIPTION OF SYMBOLS 1... Electric blower, 2... Motor, 4... Motor frame, 5... Motor case, 17... Centrifugal fan, 23... Diffuser, 25... Air passage hole.

Claims (1)

[Claims] (1) A motor in which a drive unit is housed in a motor case consisting of a motor frame and a rear case, with the front and rear of the rotating shaft protruding from the motor case, a centrifugal fan fixed to the front rotating shaft of the motor, and the centrifugal fan. and a diffuser disposed between the motor frame and the motor frame, and an intake port in the center,
a fan cover each having a plurality of exhaust ports on a side surface and attached to the motor frame so as to cover the centrifugal fan and the diffuser; a cooling fan fixed to the rear rotating shaft of the motor; a bottom surface of the rear case; A cooling air inlet and a cooling air outlet are provided on the side surfaces, respectively, and an air passage hole is provided near the center of the motor frame and the diffuser to guide a portion of the cooling air from the cooling fan toward the centrifugal fan. An electric blower characterized by the following: