JP2001238395A - Fully enclosed motor fitted with cooling rib - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fully enclosed motor fitted with a cooling rib which has a simple structure and high cooling efficiency, without having to use special apparatus or a member. SOLUTION: In a fully enclosed motor fitted with a cooling rib which is equipped with a stator iron core 17, a stator frame 16 which covers this stator iron core and has a cooling rib at its periphery, and a ventilation cover 20 which is arranged around the cooling rib of this stator frame, and cools itself by circulating cooling air in the space between the ribs made between the stator frame 16 and the ventilation cover 20, a part of the stator frame 16 opposed to the outside periphery of the stator iron core is provided with a cut 27 so as to allow the outside peripheral face of the above stator iron core to directly contact the cooling air.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fully-closed electric motor with cooling ribs, and more particularly to a stator frame which covers a stator core and has cooling ribs (cooling fins) on its outer periphery, and a cooling rib outer periphery of the stator frame. The present invention relates to a fully-closed electric motor with cooling ribs, provided with a ventilation cover disposed in a portion, for cooling the motor by flowing cooling air through a gap between the ventilation cover and the stator frame.

[0002]

2. Description of the Related Art As shown in FIGS. 7 and 8, this type of fully-closed electric motor with cooling ribs, which is generally used, is provided inside a frame (stator frame) 4 having cooling ribs 10. As shown in FIG. , A stator core 9 and a rotor 30 provided therein,
The rotor 30 is configured to rotate inside the stator core 9.

[0003] To cool the fully-closed motor with cooling ribs, air (arrows) is sucked into an end cover 3 by a fan 2 mounted on a shaft 1 of a rotor. And the air is exhausted through a cover 7 attached to a directly-connected bearing bracket 6 after passing between a ventilation cover 5 provided outside the stator frame 4.

During operation of the motor, a current flows through the coil 8 to generate heat. The heat is released from the stator core 9 through the stator frame 4 and released. Conventionally, in order to increase the heat exchange efficiency at the time of this heat radiation, as shown in FIG.
Many cooling ribs 10 are provided on the outer peripheral surface of the stator frame 4,
It is formed to increase the heat exchange efficiency.

[0005] Japanese Patent Application Laid-Open Nos. Hei 6-31689, Hei 11-285204, and Hei 9-46971 disclose such a motor related to a fully-closed electric motor with cooling ribs.

[0006]

In the fully-closed electric motor with cooling ribs formed as described above, since many cooling ribs 10 are provided on the outer peripheral surface of the stator frame 4,
Heat is released through the ribs, and there is no particular problem in the case of a small-capacity motor. However, in a large-capacity motor or a motor under severe operation, the coil 8 generates the heat. The heat dissipated through the stator core 9 and the stator frame 4 has a poor cooling efficiency, and may cause the motor to burn out.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a fully-closed electric motor with a cooling rib of this type having a high cooling efficiency with a simple structure without using any special equipment or members. Is to do.

[0008]

That is, the present invention provides a stator core, a stator frame that covers the stator core and has cooling ribs on the outer peripheral portion, and a stator frame disposed on the outer periphery of the cooling ribs of the stator frame. A cooling cover that completely cools the motor by flowing cooling air through a rib gap between the stator frame and the ventilation cover. A notch is provided in a part of the stator frame facing the surface, and the outer peripheral surface of the stator core is formed so as to directly contact the cooling air to achieve an intended purpose. It is.

The present invention also includes a stator core, a stator frame that covers the stator core and has cooling ribs on the outer periphery, and a ventilation cover disposed on the outer periphery of the cooling ribs of the stator frame. In a fully-closed electric motor with cooling ribs configured to flow cooling air through a rib gap between the stator frame and the ventilation cover to cool the motor, the motor faces the outer peripheral surface of the stator core. A notch is provided in a part of the stator frame, and a projection for guiding the cooling air to the notch side is provided on an inner peripheral surface of the ventilation cover opposed to the notch, and the guided cooling air is provided. Are formed so as to directly contact the outer peripheral portion of the stator core.

In this case, the projection is formed in substantially the same shape as the notch of the stator frame. Further, the upstream side surface of the cooling air of the projection is formed as an inclined surface facing the stator core side. In addition, a plurality of the notches may be provided at predetermined intervals in the circumferential direction of the stator frame, or may be provided all around the circumferential direction of the stator frame.

That is, in the fully-closed electric motor with cooling ribs formed as described above, a notch is provided in a part of the stator frame facing the outer peripheral surface of the stator core, and the outer periphery of the stator core is Since the surface is formed so as to be in direct contact with the cooling air, the stator core, which is the heating element, directly exchanges heat with the cooling air, thus simplifying the structure without using any special equipment or members, and cooling efficiency. Can be improved.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. 1 and 2 show the fully-closed electric motor with cooling ribs in cross section. This fully-closed electric motor with cooling ribs includes a rotor 30 having a shaft 12, a rotor core 13, a fan 14, an end ring 15, and the like.
And a stator 40 including a stator frame 16, a stator core 17, a coil 18, an end cover 19, a ventilation cover 20, and the like, and further include brackets 21 and 22, bearing covers 23 and 24, bearings 25 and 26, and the like. Have been.

When the electric motor is operated, the fan 14 rotates together with the rotor, and the air is sucked from the end cover 19 by the fan 14 so that the stator frame 16 and the stator frame 16 are rotated.
Between the ventilation cover 20 provided on the outer periphery of
Air is exhausted from the opposite end cover 28.

On the other hand, in the stator, an electric current flows through the stator coil 18 to generate heat, passes through the stator core 17, and is transferred to the stator frame 16, where heat is radiated from the cooling fins (ribs) of the stator frame and cooled by the cooling air. Heat exchanged. That is, the cooling air flows in the gap between the stator frame 16 and the ventilation cover 20 and between the cooling fins (ribs), where heat exchange is performed. Thus, the cooling air from the fan 14 absorbs the heat generated in the stator frame 4 to cool the electric motor.

In this case, the electric motor is particularly configured as follows and is formed so as to perform good cooling.
That is, FIGS. 1B and 3 show the configuration in an enlarged manner, and face a part of the stator frame located on the back side of the stator core 17, that is, the outer peripheral surface of the stator core. A notch 27 penetrating the stator frame is provided in a part of the stator frame 16. That is, the outer peripheral side of the stator core 17 is formed so as to be exposed to the cooling air.

According to this structure, the cooling air passes directly through the exposed portion, so that the stator core is efficiently cooled. Therefore, the structure can be simplified without using any special equipment or members. The cooling efficiency can be increased.

FIG. 4 shows another embodiment. In this case, the cooling efficiency is further improved, and the notch 27 is provided in a part of the stator frame 16 as in the above-described embodiment.
Further, a projection (convex portion) 1 for guiding the cooling air toward the notch 27 is provided on the inner peripheral surface of the ventilation cover 20 facing the notch 27.
1 is provided to reduce the flow passage area of the cooling air in the notch 27 so that the cooling air has an appropriate wind speed and passes as close to the stator core 17 as possible.

With such a configuration, an appropriate wind speed is provided to the cooling air, and the cooling efficiency can be further increased, which can contribute to the downsizing of the electric motor.

When the projections 11 are provided, the projections may be formed simply to guide the cooling air. However, if the projections 11 are formed to have substantially the same shape as the notch 27 of the stator frame. Since a lot of cooling air comes into contact with the core surface at a predetermined speed, the cooling will be good, and FIG.
When the surface 11a of the protrusion 11 on the upstream side of the cooling air is inclined so as to face the stator core side as shown in FIG.
Cooling air flow will be smoother and windage will be less.

Further, in the case of providing the convex portion, in the above-described embodiment, another member is fixed to the inner surface of the cover. However, it is not always necessary to form the convex portion as shown in FIG. As shown, the ventilation cover 20
It may be possible to form the projection itself to form the projection.

The notches provided in the stator frame 16 have also been described as being provided at predetermined intervals in the circumferential direction in the above description. However, if a small-capacity electric motor is used, the notch is required in terms of mechanical strength. If allowed, it would be more effective to provide the stator frame 16 on the entire circumference in the circumferential direction.

[0022]

As described above, according to the present invention, this type of fully-closed motor with cooling ribs having high cooling efficiency can be obtained with a simple structure without using any special equipment or members.

[Brief description of the drawings]

FIG. 1 is a partially longitudinal side view and a main part enlarged view of a fully-closed electric motor with cooling ribs of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is an enlarged view of a main part of FIG. 2;

FIG. 4 is an enlarged sectional view showing a main part of an embodiment of the fully-closed electric motor with cooling ribs according to the present invention.

FIG. 5 is an enlarged sectional view showing a main part of another embodiment of the fully-closed electric motor with cooling ribs according to the present invention.

FIG. 6 is an enlarged sectional view showing a main part of another embodiment of the fully-closed electric motor with cooling ribs according to the present invention.

FIG. 7 is a partially longitudinal side view of a conventional fully-closed electric motor with cooling ribs.

FIG. 8 is a sectional view taken along line BB of FIG. 7;

FIG. 9 is an enlarged view of a main part of FIG. 8;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... shaft, 2 ... fan, 3 ... end cover, 4 ... stator frame, 5 ... ventilation cover, 6 ... bearing bracket,
7 ... Cover, 8 ... Coil, 9 ... Stator core, 10 ... Cooling rib (cooling fin), 11 ... Protrusion, 12 ... Shaft, 1
3 ... rotor core, 14 ... fan, 15 ... end ring,
16 ... stator frame (frame), 17 ... stator core, 18
... Coil, 19 ... Cover, 20 ... Ventilation cover, 21, 22
2 ... bracket, 23, 24 ... bearing cover, 2
5, 26 ... bearing, 27 ... notch, 28 ... cover,
30 ... rotor, 40 ... stator.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Noboru Kondo 3-1-1 Sachimachi, Hitachi-shi, Ibaraki Pref. Hitachi, Ltd. Hitachi Works (72) Inventor Kenzo Kajiwara 3-1-1 Sachimachi, Hitachi-shi, Ibaraki No. 1 Hitachi, Ltd. Hitachi Works (72) Inventor Tetsuro Fujigaki 3-1-1 Kochicho, Hitachi City, Ibaraki Prefecture Within Hitachi Works Hitachi Works, Ltd. (72) Inventor Kazuo Usami Hitachi, Ibaraki Prefecture 3-2-1 Sachimachi Hitachi Engineering Co., Ltd. F-term (reference) 5H605 AA01 BB05 BB17 CC01 DD01 DD03 DD07 DD12 EB10 EB12 5H609 BB12 BB19 PP01 PP05 PP06 PP08 QQ02 QQ12 QQ23 RR03 RR24 RR27 RR35 RR36RR RR73

Claims (6)

[Claims] 1. A stator core comprising: a stator core; a stator frame that covers the stator core and has a cooling rib on an outer peripheral portion; and a ventilation cover disposed on an outer peripheral portion of the cooling rib of the stator frame. In a fully-closed electric motor with cooling ribs configured to cool a motor by flowing cooling air through a rib gap between a child frame and the ventilation cover, a stator frame facing an outer peripheral surface of the stator core. A fully closed motor with cooling ribs, wherein a notch is provided in a part of the motor so that an outer peripheral surface of the stator core is in direct contact with the cooling air. 2. A stator core comprising: a stator core; a stator frame that covers the stator core and has a cooling rib on an outer peripheral portion; and a ventilation cover disposed on an outer peripheral portion of the cooling rib of the stator frame. In a fully-closed electric motor with cooling ribs configured to circulate cooling air through a rib gap between a child frame and the ventilation cover to cool the motor, a stator frame facing an outer peripheral surface of the stator core is provided. A notch is provided in a part of the airflow cover, and a projection for guiding the cooling air to the notch side is provided on an inner peripheral surface of the ventilation cover facing the notch, and the guided cooling air is fixed to the fixed portion. A fully-closed electric motor with cooling ribs, which is formed so as to directly contact an outer peripheral portion of a child core. 3. The fully-closed electric motor with cooling ribs according to claim 2, wherein said projection is formed in substantially the same shape as a notch of said stator frame. 4. The cooling air upstream side surface of the projection is formed on an inclined surface facing the stator core side.
Or a fully-closed electric motor with a cooling rib according to 3. 5. A plurality of notches are provided at predetermined intervals in a circumferential direction of a stator frame.
A fully-closed electric motor with a cooling rib according to 2, 3, or 4. 6. The fully-closed electric motor with cooling ribs according to claim 1, wherein the notch is provided on the entire circumference of the stator frame in the circumferential direction.