JPH04127855A - Motor fan - Google Patents

Abstract

PURPOSE:To cool a rotor efficiently without sacrifice of aerodynamic performance of a motor fan by disposing a substantially semicircular cooling board in a cooling air path between a fan and a motor. CONSTITUTION:Air flow delivered from a centrifugal impeller 32 secured to the shaft 26 at a fan section 3 is introduced by a fixed guide vane 31 into a housing 21 through a vent 27b in an end bracket 27 and discharged through a discharge port 21b while cooling a stator 22 and a rotor 23. Flow path in the housing 21 comprises outer peripheral flow paths 41a-41d of the stator 22 and an air gap between the stator 22 and the rotor 23, and a substantially semicircular detecting circuit 25 is disposed, as a cooling board, in the upstream of the flow path such that the detecting circuit 25 chokes the outer peripheral flow paths 41a, 41b. According to the constitution, cooling air flowing to the air gap side is increased and the rotor is cooled sufficiently without sacrifice of the cooling effect of the stator, and thereby degradation of motor performance due to temperature rise can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION r Industrial Application Field The present invention relates to an improvement in aerodynamic performance and a motor cooling structure in an electric blower.

[Conventional technology]

Conventionally, in electric blowers with brushless motors,
As seen in Japanese Patent Laid-Open No. 61-15555, the cooling air passage structure of the electric motor was constructed so that the cooling air flowed through an air gap between the stator and rotor within the electric motor. In other examples, the rotor and stator are housed in a housing, and a flow path is provided in the gap between the inner circumference of the housing and the outer circumference of the stator.

[Problems to be Solved by the Invention] In the above-mentioned prior art, in the first example, the air gap between the rotor and the stator is usually configured to be very small in order to prevent leakage of magnetic flux in view of the performance of the electric motor. Therefore, the flow path area is small, that is, the airflow resistance is large, so the aerodynamic performance of the blower may be reduced.

In addition, when a flow path is provided on the outer circumferential side of the stator in the second example,
Normally, the area is larger than the above air gap, so the cooling air concentrates on the outer circumferential side of the stator, and the cooling air on the air gap side decreases, resulting in an increase in rotor temperature due to insufficient cooling, and rotor permanent magnets. 9. There was a risk of deterioration of motor performance due to decrease in magnetic flux, etc.

The present invention aims to prevent deterioration of the cooling structure and aerodynamic performance of an electric blower.

[Means for Solving the Problems] In order to achieve the above object, cooling air passages are provided in the air gap between the rotor and stator and on the outer circumferential side of the stator in the electric blower, and cooling air passages between the blower and the electric motor are provided. On the road,
A roughly semicircular cooling plate was arranged.

Furthermore, in an electric blower using a brushless motor as an electric motor, the cooling plate is constituted by a detection circuit board that detects the magnetic poles of the rotor permanent magnets.

[Function] The cooling plate blocks approximately 1/2 of the flow path formed on the outer circumferential side of the stator, so the amount of air flowing into the air gap between the rotor and stator increases, and the rotor This can prevent insufficient cooling. Therefore, it is possible to prevent a decrease in motor performance due to a rise in rotor temperature.

In addition, 1/2 of the cooling air passage remains on the outer circumferential side of the stator,
Unlike the conventional example, this does not cause a decrease in aerodynamic performance.

As described above, according to the present invention, the rotor can be effectively cooled without deteriorating the aerodynamic performance of the electric blower.

[Example〕 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the overall configuration of an electric blower for a vacuum cleaner showing one embodiment of the present invention. In the figure, the electric blower 1 is
Electric motor section 2 and blower section 3 consisting of a brushless motor
Consisted of. The electric motor unit 2 houses a stator 22 , a rotor 23 having a permanent magnet 24 , and a detection circuit 25 for detecting the magnetic pole position of the rotor 23 in a housing 21 . It is supported by bearing parts 21a and 27a of the end bracket 27. The blower 3 includes a fan casing 33 on which fixed guide vanes 31 are arranged on the end bracket 27 and covers a centrifugal impeller 32 integrally fixed to the shaft 26 .

The airflow discharged by the centrifugal impeller 32 is guided by the fixed guide vane 31 and passes through the air hole 2 of the end bracket 27.
7b, it passes through the housing 21 and is discharged from the exhaust port 21b while cooling the stator 22 and rotor 23.

Here, the flow path in the housing 21 is the outer peripheral side flow path 40a of the stator 22, as shown in FIG.

40b, c, and d, and an air gap is formed between the stator 22 and the rotor 23, and on the upstream side of the flow path, a detection circuit 25 having a substantially semicircular shape shown in FIG.
, 40b.

On the detection circuit 25, there are Hall ICs, 25a, and 25b.

25c is provided and is located on the outer periphery of the rotor 23 to detect the magnetic poles of the rotor 23. The rotor 23 is connected to the shaft 2
6, a press-fitted core 28, a plurality of permanent magnets 24 around its outer periphery, and a cylindrical cover 29 made of a non-magnetic material covers the outer periphery. The cover 29 has a permanent magnet 2
In order to prevent breakage etc. of 4, it is made of metal for strength reasons.

When the electric blower 1 is operated, there is a copper loss in the stator winding 22a, an iron loss in the stator core 22b, a loss in the cover 29 of the rotor 23, or a loss in the bearing portion 21a.

Temperature rise occurs due to mechanical loss etc. at 27a.

In order to cool this, the exhaust flow from the blower section 3 is guided into the electric motor 2, but normally the rotor 23 and stator 2 are
Since the air gap between the outer peripheral side flow paths 40a, 40b, and 40c is minute.

40d has a larger area, and the above-mentioned exhaust flow, that is, cooling air, flows through these outer peripheral side flow paths 40a, 40b, and 40c.

40d, and hardly flows into the air gap. Therefore, the rotor 23 may not be cooled sufficiently, resulting in an increase in loss in the cover 29, a decrease in the magnetic flux of the permanent magnets 24, etc., which may lead to a decrease in the performance of the electric motor 2.

In the present invention, the detection circuit 25 detects the outer flow path 40a.
, 40b are closed to increase the amount of cooling air flowing to the air gap side, thereby preventing insufficient cooling of the rotor 23. Outer circumferential flow paths 40a, 40b.

If 40c and 40d are all closed, the cooling effect of the rotor 23 will be:
However, in that case, the aerodynamic performance of the electric blower 1 will decrease due to insufficient cooling of the stator 22 and increased ventilation resistance, so it is difficult to cool the rotor 23 without causing these problems. The configuration of the present invention is effective.

Further, since the detection circuit 25 is a necessary component of the brushless motor that constitutes the electric motor unit 2, the above-mentioned cooling effect can be obtained without increasing the number of special parts.

FIGS. 4 and 5 show an example of use in an electric blower 1 using a commutator motor.

In the case of a commutator motor, like the brushless motor described above, the detection circuit 25 is not required as a component and the cooling plate 4
5 are similarly arranged.

In the commutator motor, the winding 23a is also wound around the rotor 23, which causes a rise in temperature.

Therefore, the present invention is more effective as the necessity of cooling is increased.

[Advantageous Effects of the Invention 1] According to the present invention, the rotor 23 is sufficiently cooled without deteriorating the aerodynamic performance of the electric blower 1 and without impairing the cooling effect of the stator 22. 2 can be prevented from deteriorating in performance. Further, when the electric motor section 2 is configured by a brushless motor, the cooling effect described above can be obtained without increasing the number of parts by configuring the cooling plate by a detection circuit.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of an electric blower according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the electric motor section 2, FIG. 3 is a perspective view of a detection circuit, and FIG. 4 is an electric blower according to another embodiment of the present invention. Longitudinal cross-sectional view of the blower, No. 5
The figure is a perspective view. 2... Electric motor section, 22... Stator, 23... Rotor, 25... Detection circuit, 45 ・= Cooling plate, 40 a
, 40b, 40c. Kusazu Hayabusa? The first stop

Claims (1)

[Claims] 1. In an electric blower that consists of an electric motor and a blower attached to the rotating shaft of the electric motor, and that cools the electric motor using the airflow discharged from the blower, a flow path between the blower and the electric motor has a substantially semicircular shape. An electric blower characterized by being equipped with a cooling plate. 2. In claim 1, the electric motor has a rotor and a stator in a housing, and the cooling plate is disposed in the housing and blocks approximately 1/2 of one side of the flow path in the housing. An electric blower that is characterized by 3. The electric motor according to claim 2, wherein the electric motor is a brushless motor having a rotor made of a permanent magnet, and the cooling plate constitutes a detection circuit for detecting magnetic poles of the rotor. Blower.