JPH0350119B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electric blower that makes a relatively loud noise and is suitable for use in, for example, a vacuum cleaner.

[Conventional technology]

Conventionally, this type of electric motor has been used in the electric blower shown in Fig. 3, and these will be explained based on the figure. 1 is an external blower having an impeller 2, and 3 is a bracket having an internal ventilation hole 4a. This is an AC commutator type motor having a rotor 5 and a stator 6 arranged on the opposite side of the blower 4, and the rotor 5 has an iron core 7 and a commutator 8 arranged in the axial direction of the iron core. , a winding 9 connected to the commutator and wound around the slot of the iron core 7, and fixed to a motor shaft 11 supported within a motor frame 10 having an exhaust hole 10a. On the other hand, the stator 6 has an iron core 12 and a winding 13 wound in a slot of the iron core, and is arranged at a distance 14 in the radial direction of the rotor 5. Also, 15 is brush 1
One end of the winding 13 of the stator 6 extends through the frame 10 and is connected to the terminal 17.
In addition, 18 is a fan cover, 19 is a guide vane, 20
is a bearing.

In the electric blower configured in this way, as shown by the arrow in FIG. The stator 6 is cooled and discharged to the outside from the exhaust hole 10a.

[Problem that the invention seeks to solve]

In conventional electric blowers, the exhaust hole 10 is
Since a is open at the rear of the frame, there is a problem in that the sound energy generated by the blower and the electric motor is directly emitted to the outside, increasing noise. Furthermore, since the wires from the stator to the brushes are connected to the terminals of the brush holder by passing through the frame, the wire connection work is complicated and is an obstacle to automation.

In view of such conventional examples, the present invention provides an electric blower that reduces the noise generated with exhaust gas and has good wiring workability.

[Means for Solving the Problems] In the case of the present invention, a sealed outer shell casing is configured to have a sealed structure from a large-diameter chamber-side frame, a small-diameter chamber-side bracket, and a flange portion that connects the opening edges of both. , a brush holder placed opposite the commutator is housed in the large-diameter indoor frame, and the cooling air that passes through the internal motor and is collected in the large-diameter indoor frame is reversed to provide an exhaust air provided at the flange. It is made to drain through the hole.

[Effect]

In the case of this invention, after cooling the rotor and stator, the cooling air sent from the blower is turned 180 degrees, passes through the exhaust hole provided in the flange, and is discharged into free space. Sound energy is not directly released to the outside with the exhaust gas, thereby reducing noise. Furthermore, since the brush holder is housed within the frame on the large diameter chamber side of the outer shell casing, there is no need to take out the connection between the brush holder and the stator to the outside.

〔Example〕

FIG. 1 is a sectional view showing an embodiment of an electric blower according to the present invention, and the same parts as in the conventional one shown in FIG. In the figure, reference numeral 31 denotes a small-diameter chamber A-side bracket disposed on the blower side, which has a ventilation hole 31a for cooling air blown out from the blower 1 on its end wall, and the stator 6 is housed and fixed therein by press-fitting or the like. are doing. On the other hand, a flange portion 31b larger than the outer diameter of the stator is formed in series on the edge of the opening and extends outward in a direction perpendicular to the motor shaft 11.
The opening edge of the large-diameter chamber-side frame 32 is fitted into the large-diameter chamber frame 32 by press-fitting or the like, and the flange portion 31b is provided with a plurality of exhaust holes 31d. A brush holder 33 is located within the large-diameter chamber side frame 32 and fixed to the flange portion 31b, and is provided with a brush 34 such that its tip is in contact with the commutator 8. The brush 34 has a terminal 35 to which one end of the winding 13 of the stator 6 is directly connected, and the terminal provided at the terminal has a notch 32a provided in the large diameter chamber side frame 32. An external power supply is connected using the . That is, the large-diameter chamber-side frame 32 has a substantially sealed structure except for the notch 32a, which is automatically closed by the brush holder 33. Further, 38 is a support plate that supports the blower 1.

Therefore, as shown by the arrow in FIG.
It turns 180 degrees, passes through the ventilation hole 31a, cools the rotor 5 and stator 6, passes through the gap inside these and the large-diameter room side frame 32, turns 180 degrees inside it, and passes through the flange portion 31b. is discharged into free space through the exhaust hole 31d.

Since the present invention is constructed as described above, sound energy that travels in a straight line is attenuated by reflection and absorption as it is repeatedly diverted, making it possible to reduce the noise generated with exhaust air. An example of this is shown in Figure 2 a and b, and as can be seen from these figures, when compared at 1 m to the side of the exhaust hole, the
A reduction effect of approximately 5 dB was observed when compared at a distance of 9 dB and 1 m from the side end face of the large-diameter indoor frame, and the effect was more pronounced at higher frequencies. Also, determine the area of the exhaust hole appropriately (flow rate
(area required to be 10m/sec or less),
It does not compromise the blower performance. Furthermore, since both the terminals of the brush holder and the terminals are arranged within the large-diameter chamber side frame, all the connections of the stator windings can be made before the large-diameter chamber side frame is assembled.

Note that the wind pressure generated by blower 1 is the same as that of impeller 2.
Since it is approximately determined by the circumferential velocity at the exit of
In order to obtain high wind pressure, it is necessary to increase the rotation speed or to increase the outer diameter Di of the impeller 2. However, when the number of rotations is increased, there are restrictions on the rotational strength of the rotor 5, the fan, etc., the life of the bearing 20, etc., and therefore there is a general tendency to increase the outer diameter Di of the impeller 2.

As a result, in a conventional electric blower using an electric motor, the outer diameter Db of the blower 1 is larger than the outer diameter Dm of the motor portion, and a so-called dead space C is formed in the radial direction of the motor portion.

On the other hand, in the case of the present invention, the dead space C can be effectively used for changing the wind direction as long as it is within the blower outer diameter Db, and this allows the outer diameter Df of the large-diameter indoor frame 32 to be relatively freely adjusted. Can be set to . Therefore, the above exhaust hole 3
It also becomes easy to set the area of 1d and the length dimensions of the brush and brush holder.

[Effects of the Invention] As described above, the electric blower of the present invention has an outer shell casing arranged between a frame on the large-diameter chamber side, a bracket on the small-diameter chamber side, and a large-diameter chamber provided at the opening edge of the bracket so as to be larger than the outer diameter of the stator. A connecting flange with the side frame opening edge is formed, and an exhaust hole is provided in this connecting flange to reverse the cooling air by 180 degrees within the large diameter room side frame, which may impair blower performance. Noise can be reduced without
Furthermore, since the brush holder is provided within the frame on the large-diameter chamber side, wiring can be connected before assembling the frame, which also improves assembly work efficiency.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the electric blower of the present invention, and FIGS. 2a and 2b are comparison data between the present invention and a conventional example showing noise measurement results. Third
The figure is a sectional view showing a conventional electric blower. In the figure, 1 is a blower, 6 is a stator, 8 is a commutator, 31 is a small diameter chamber side bracket, 31a is a ventilation hole, 31b is a flange part, 31d is an exhaust hole, 32
33 is a brush holder, A is a small diameter chamber, and B is a large diameter chamber. In other figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A large-diameter chamber side frame that houses the commutator and the brush holder placed opposite to it, and a stator that is housed and fixed.
A small-diameter chamber-side bracket with a ventilation hole from an external blower in its end wall, and a flange portion that connects the opening edges of the large-diameter chamber-side frame and the small-diameter chamber-side bracket to form a sealed outer shell casing. The electric blower is characterized in that the flange portion is provided with an exhaust hole for cooling air which is blown out from the ventilation hole, passes through an internal blower driving electric motor, and is reversed within the large-diameter indoor frame.