JPH0974707A - Bearing cooling device for dynamo-electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit the temperature rise of a bearing by sufficiently transmitting heat to a bracket through a housing from a shaft. SOLUTION: In a bearing cooling device for a dynamo-electric machine with a bracket 2 installed at the end section of a frame, a housing 21 mounted on the bracket 2, a bearing 4 housed in the housing 21, a shaft 3, on which a rotor is fixed and which is borne by the bearing 4, an internal cover 22 covering the rotor side of the bearing 4 and being set up to the housing 21 and an external cover 23 covering the outside of the bearing 4 and being fitted to the housing 21, a cylinder section 22A is installed onto a face oppositely faced to the shaft 3 of the internal cover 22 in the axial direction through an air gap.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing cooling device for a fully enclosed rotary electric machine.

[0002]

2. Description of the Related Art Conventionally, as a bearing cooling structure for a rotating electric machine,
For example, as shown as a first conventional example in FIG. 5A, a stator 10 is fixed inside a hollow cylindrical frame 1, a bracket 2 is provided at an end of the frame 1, and the bracket 2 has a rotating shaft. A housing 21 for accommodating a bearing 4 supporting 3
Is provided. The rotor 30 is fixed to the rotating shaft 3. In the housing 21, as shown in FIG.
Inner cover 2 covering the bearing 4 and the housing 21 fitted in the
2 and the outer cover 23 are attached, and the space portions 6A and 6B are provided between the inner cover 22 and the bearing 4 and between the outer cover 23 and the bearing 4, respectively, and both the space portions 6A are provided in the housing 21 and the rotary shaft 3, respectively. , 6B are provided with holes 21A, 3A communicating with the air bearings 4A, 6B so that the air in both space portions 6A, 6B circulates, and the bearing 4 is cooled (for example, Japanese Patent Laid-Open No. Hei 4). -1852
No. 60). In addition, as shown as a second conventional example in FIGS. 5 (b) and 7, for example, the rotating shaft 3 is attached to the housing 21.
Inner cover 2 covering the bearing 4 and the housing 21 fitted in the
2 and the outer cover 23 are attached, and further the inner cover 2
A ring-shaped cover 50 that covers the back surface of the second cover 2 is provided, and a space 6 is provided between the inner cover 22, the housing 21, and the cover 50. An oil draining portion 24 is provided on the surface of the inner cover 22 facing the rotating shaft 3, and a hole 25 for communicating the space 6 with the outside air is provided in the housing 21 and the bracket 2. With such a structure, there is disclosed a structure in which the temperature rise of the bearing 4 is suppressed by introducing cold outside air around the bearing (for example, JP-A-5-1066639).
issue).

[0003]

However, in the above-mentioned prior art, since the cover is formed in a thin plate shape, the cross-sectional area of the passage of the heat transmitted to the housing through the cover is narrow, and the rotation shaft is However, there was a problem that the heat of the bearing was not sufficiently transmitted to the bracket and the temperature of the bearing was not sufficiently lowered.
It is an object of the present invention to provide a bearing cooling device for a rotary electric machine, which transfers heat reaching a bearing via a rotating shaft to a bracket before being transferred to the bearing, thereby suppressing an increase in temperature of the bearing. .

[0004]

In order to solve the above problems, the present invention provides a hollow frame to which a stator is attached, a bracket attached to the end of the frame, and a housing provided on the bracket. A bearing housed in the housing, a rotating shaft that fixes the rotor facing the stator through a gap and is supported by the bearing, and an inner side that covers the rotor side of the bearing and is attached to the housing. A bearing cooling device for a rotating electric machine, comprising: a cover; a space provided between the inner cover, the bearing, and the rotating shaft; and an outer cover that covers an outer side of the bearing and is attached to the housing. A cylindrical portion is provided in the axial direction on the surface of the inner cover facing the rotation axis through a gap. Also, a hollow frame to which a stator is attached, a bracket attached to the end of the frame, a housing provided on the bracket, a bearing housed in the housing, and a stator that faces the stator via a gap. A rotating shaft that fixes the rotor to be supported by the bearing, an inner cover that covers the rotor side of the bearing and is attached to the housing, and an outer cover that covers the outside of the bearing and is attached to the housing. In a bearing cooling device for a rotating electric machine, comprising: the inner cover and a cover that faces a space portion, a surface of the thermal bypass cover that faces the rotating shaft, the heat bypass cover being mounted on the bracket. A cylindrical portion is provided in the axial direction through a void. Further, ring-shaped concavities and convexities that engage with each other through a gap are provided on the surfaces of the cylindrical portion of the above-mentioned means and the rotating shaft that face each other.

[0005]

By the above means, the heat transferred from the stator or the rotor to the rotary shaft is transferred to the axially long heat bypass cover or the cylindrical portion of the inner cover which opposes the rotary shaft through the gap. Since the heat transfer area from the rotating shaft to the heat bypass cover is large and the heat resistance is small, the heat of the rotating shaft is hardly transferred to the bearings, and most of the heat is not transmitted to the bearings or the bracket through the inner cover. Transmitted to and dissipated. Further, ring-shaped concavities and convexities facing each other through a gap are provided on respective surfaces of the cylindrical portion and the rotating shaft, which face each other, to increase the area of the heat transfer surface from the rotating shaft to the cylindrical portion. The efficiency of heat transfer from the rotary shaft to the heat bypass cover or the inner cover can be increased.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view showing an essential part of a first embodiment of the present invention, and the entire structure of the rotary electric machine is the same as that used in the description of the conventional example.
Is almost the same as In the figure, 2 is a bracket attached to the end of the frame 1 shown in FIG. 5, 21 is a housing provided in the bracket 2, 3 is a rotary shaft to which the rotor 30 shown in FIG. 5 is fixed, and 4 is a housing 21. The bearing housed in rotatably supports the rotating shaft 3. An inner cover 22 is fixed to the housing 21 and covers the rotor side of the bearing 4, and a cylindrical portion 22A is provided in a portion of the inner cover 22 facing the rotating shaft 3. Reference numeral 23 is an outer cover fixed to the housing 21 and covering the outer side of the bearing 4, and 24 is an oil draining portion provided on the surface of the inner cover 22 facing the rotating shaft 3. There is a bulge between the portion of the inner cover 22 fixed to the housing 21 and the cylindrical portion 22A.
A space portion 6 is formed between the oil removing portion 24, the oil removing portion 24, and the rotating shaft 3. In this case, a heat insulating collar 26 made of a low heat conductive material such as ceramic is provided between the inner cover 22 and the bearing 4.
And a ring-shaped notch groove 27 is provided on the inner surface of the housing 21 between the inner cover 22 and the bearing 4.
With such a configuration, the heat transferred from the stator 10 and the rotor 30 to the rotary shaft 3 is applied to the cylindrical portion 2 of the inner cover 22.
2A is transmitted to the housing 21, and further the bracket 2
Is emitted from. The heat transferred from the inner cover 22 to the bearing 4 is blocked by the heat insulating collar 26, so that the bearing 4
Very little heat is transferred to the. In addition, the housing 21
Since the notch groove 27 is provided in the inner cover 22,
The heat transferred from the housing 21 to the housing 21 is blocked by the notch groove 27, and the heat transferred to the bearing 4 is reduced.

FIG. 2 is a side sectional view showing a second embodiment of the present invention. This is one in which a heat bypass cover 5 is provided on the motor side of the inner cover 22 of the first embodiment shown in FIG. 1, and the heat bypass cover 5 is made of a high heat conductive material such as copper or aluminum. It is provided on the rotor side of 22. Reference numeral 51 is a flange portion of the thermal bypass cover 5 fixed to the bracket 2, 52 is an axially long cylindrical portion facing the rotating shaft 3 with a slight gap, and 6 is between the thermal bypass cover 5 and the inner cover 22. It is a space part formed in. With such a configuration, the stator 10 and the rotor 3
The heat transferred to the rotary shaft 3 from 0 or the like is transferred to the axially long cylindrical portion 52 facing the rotary shaft 3 with a gap, so that the heat transfer portion from the rotary shaft 3 to the thermal bypass cover 5 is Since the area is large and the thermal resistance is small, most of the heat of the rotating shaft 3 is transferred to the bracket 2 via the flange portion 51. The heat transfer efficiency is increased by increasing the surface area of the heat transfer from the rotary shaft 3 to the heat bypass cover 5 by roughening the surface roughness of the inner surface of the cylindrical portion 52 of the heat bypass cover 5 facing the rotary shaft 3. Can be increased. In addition, the surfaces of the thermal bypass cover 5 and the inner cover 22 that face each other,
Also, by spraying a material having a low thermal conductivity such as ceramics on the outer surface of the thermal bypass cover 5 to form a low thermal conductive film, radiant heat from the thermal bypass cover 5 or heat transmitted through the space 6 and rotation Radiant heat from the inside of the electric machine can be blocked, and the temperature rise of the bearing 4 can be prevented.

FIG. 3 is a side sectional view showing a third embodiment of the present invention. This is one in which the inner circumference of the cylindrical portion 22A of the inner cover 22 described in the first embodiment is in close contact with the inner circumference of the cylindrical portion 52 of the thermal bypass cover 5 described in the second embodiment. With such a configuration, the heat transferred from the stator 10 and the rotor 30 to the rotary shaft 3 is transferred to the cylindrical portion 22A of the inner cover 22 that faces the rotary shaft 3 through the gap, and further the heat bypass is performed. It is transmitted to the cylindrical portion 52 of the cover 5 and then transmitted to the bracket 2. Therefore, the heat transferred from the inner cover 22 to the housing 51 is reduced as compared with the case of the first embodiment, and the temperature rise of the bearing 4 is further reduced.

FIG. 4 is a side sectional view showing a fourth embodiment of the present invention. In this case, the thermal bypass cover 5 described in the second embodiment is divided into two in the radial direction, and the cylindrical portion 52 is formed.
At least one ring-shaped convex portion 53 is provided on the inner surface of the. Further, a ring-shaped concave portion 31 is provided on the outer peripheral surface of the rotating shaft 3 facing the cylindrical portion 52 so that the ring-shaped convex portion 53 meshes with a gap. The procedure of assembling the bearing 4 on the rotary shaft 3 is performed by dividing the ring-shaped convex portion 5 of the thermal bypass cover 5 into pieces.
3 is inserted into the ring-shaped recess 31 of the rotary shaft 3, and the thermal bypass cover 5 is integrally combined. After that, the oil draining portion 24 is fitted on the rotating shaft 3, and the inner cover 22 is attached to the oil draining portion 2.
4, the bearing 4 is fitted to the rotary shaft 3, the housing 21 is fitted to the outer periphery of the bearing 4, and the thermal bypass cover 5 is attached to the bracket. Finally, the inner cover 22, the housing 21, and the outer cover 23 are fixed by tightening with bolts. With such a configuration, the heat transfer surface formed by the ring-shaped convex portion 53 provided on the cylindrical portion 52 of the thermal bypass cover 5 and the ring-shaped concave portion 31 provided on the rotating shaft 3 facing each other is the first. The heat transfer efficiency from the rotating shaft 3 to the heat bypass cover 5 can be increased because the number of cylinders is increased more than in the case of the cylindrical surface shown in the embodiment. In the above embodiment, an example in which the ring-shaped convex portion is provided on the thermal bypass cover has been described, but the effect is the same if the ring-shaped convex portion is provided on the rotating shaft and the ring-shaped concave portion is provided on the thermal bypass cover. Further, the ring-shaped uneven portion may be provided on the surfaces of the inner cover and the rotating shaft, which are described in the first and fourth embodiments, facing each other.

[0010]

As described above, according to the present invention, the area of the heat transfer surface from the rotary shaft is provided by providing the axially long cylindrical portion in the portion of the heat bypass cover or the inner cover facing the rotary shaft. Since it has a large size, it is possible to improve the efficiency of heat transfer from the rotating shaft to the heat bypass cover or the inner cover, and to reduce the amount of heat transfer to the bearings. There is an effect that the device can be provided.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a first embodiment of the present invention.

FIG. 2 is a side sectional view showing a second embodiment of the present invention.

FIG. 3 is a side sectional view showing a third embodiment of the present invention.

FIG. 4 is a side sectional view showing a fourth embodiment of the present invention.

5A is a side sectional view showing a first conventional example, and FIG. 5B is a side sectional view showing a second conventional example.

FIG. 6 is a side sectional view showing a first conventional example.

FIG. 7 is a side sectional view showing a second conventional example.

[Explanation of symbols]

1: frame, 10: stator, 2: bracket, 21:
Housing, 22: inner cover, 22A: cylindrical portion, 2
3: outer cover, 24: oil draining part, 26: heat insulating collar,
27: Notch groove, 3: Rotating shaft, 30: Rotor, 31: Ring-shaped recess, 4: Bearing, 5: Thermal bypass cover, 51:
Flange part, 52: Cylindrical part, 53: Ring-shaped convex part, 6
Space

Claims (6)

[Claims] 1. A hollow frame to which a stator is attached, a bracket attached to an end of the frame, a housing provided in the bracket, a bearing housed in the housing, and a gap in the stator. A rotor that fixes the rotors that are opposed to each other with the rotor supported by the bearing, an inner cover that covers the rotor side of the bearing and is attached to the housing, the inner cover, the bearing, and the rotating shaft. In a bearing cooling device for a rotating electric machine, comprising a space portion provided between the bearing and an outer cover that covers the outer side of the bearing and is attached to the housing, a gap is provided in a surface of the inner cover facing the rotating shaft. A bearing cooling device for a rotating electric machine, wherein a cylindrical portion is provided in an axial direction. 2. A hollow frame to which a stator is attached, a bracket attached to an end of the frame, a housing provided on the bracket, a bearing housed in the housing, and a gap in the stator. A rotor that fixes the rotors that are opposed to each other via a bearing supported by the bearing, an inner cover that covers the rotor side of the bearing and is attached to the housing, and an outer cover that covers the outside of the bearing and is attached to the housing. In a bearing cooling device for a rotating electric machine comprising an outer cover and a cover facing the inner cover via a space, the cover is attached to the bracket to form a thermal bypass cover, and the rotary shaft of the thermal bypass cover is attached to the rotary shaft. A bearing cooling device for a rotary electric machine, wherein a cylindrical portion is provided in an axial direction on opposing surfaces with a gap therebetween. 3. The inner circumference of the cylindrical portion of the inner cover and the inner circumference of the cylindrical portion of the thermal bypass cover attached to the bracket so as to face the inner cover with a space therebetween. Item 1. A bearing cooling device for a rotating electric machine according to Item 1. 4. The rotating electric machine according to claim 1, wherein ring-shaped concaves and convexes that engage with each other through a gap are provided on respective surfaces of the cylindrical portion and the rotating shaft that face each other. Bearing cooling device. 5. The heat insulating collar made of a low heat conductive material is inserted between the inner cover and the bearing.
The bearing cooling device for a rotary electric machine according to any one of items 1 to 7. 6. A low thermal conductive film is formed by spraying a material having a low thermal conductivity on at least one of the surfaces of the thermal bypass cover and the inner cover which face each other and the outer surface of the thermal bias cover. The bearing cooling device for a rotating electric machine according to any one of 2 to 5.