JPH109276A - Bearing cooling device for rotating electric machines - Google Patents

Abstract

(57) [Summary] [PROBLEMS] A highly reliable rotating electric machine capable of effectively dissipating heat to the outside air and reducing the amount of heat transferred from the rotating shaft to the bearing without increasing the temperature rise of the bearing. A bearing cooling device is provided. A housing provided on a bracket (2).
And a bearing cooling device for a rotating electrical machine having a bearing 4 fitted to the housing 21 and a rotating shaft 3 fixed to the rotor and supported by the bearing 4, dissipates heat between the bearing inner ring 4 b and the rotating shaft 3. A ring 5 is fitted, a first fin 51 provided on the bearing inner ring 4b side and inclined in the circumferential direction as viewed from the shaft end side, and provided on the rotation shaft 3 side on the rotation shaft end side of the heat radiation ring 5. Since a plurality of second fins 52 are arranged in a direction opposite to the first fins 51 when viewed from the shaft end side, forced air cooling is performed by both the fins and the heat radiating ring 5 with rotation. Thereby, heat radiation from the rotating shaft 3 is promoted, and the amount of heat transfer to the bearing 4 is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a bearing cooling device for a rotating electric machine.

[0002]

2. Description of the Related Art Conventionally, a rotating electric machine is, for example, shown in FIG. A stator 10 is fixed inside a hollow cylindrical frame 1, a bracket 2 having a heat radiating portion is provided at an end of the frame 1, and a bearing 4 for supporting a rotating shaft 3 is housed in the bracket 2. A housing 21 is provided. An outer ring 4a of the bearing 4 is fixed to an inner periphery of the housing 21,
The rotating shaft 3 is directly supported and fixed to the inner ring 4 b of the bearing 4. The rotor 30 is fixed to the rotating shaft 3.

[0003]

However, the rotating electric machine shown in the prior art has a structure in which the temperature of the bearing is greatly increased because the rotating shaft is in direct contact with the bearing inner ring. In addition, the heat transfer path of the heat generated by the stator and the rotor of the rotating electric machine is at least the path that is directly transmitted from the heat generating section to the rotating shaft and then transferred to the bearing, and the heat generating section warms the inside air and heats the inside air. There are three paths: a path that transfers heat to the bearing, and a path that transfers heat to the bearing by radiation of generated heat. As described above, there is a problem that the generated heat is transmitted to the bearing, and the temperature rise is large. As a result, as the temperature of the bearing increases, the life of the grease filled in the bearing decreases, and the bearing gap decreases due to thermal expansion. It was an obstacle to cause poor rotation. Therefore, the present invention effectively reduces the amount of heat transferred from the rotating shaft to the bearing by effectively radiating heat to the outside air so as not to increase the temperature rise of the bearing. Does not cause reduction in bearing clearance due to thermal expansion,
An object of the present invention is to provide a highly reliable bearing cooling device for a rotating electric machine.

[0004]

SUMMARY OF THE INVENTION To solve the above problems, the present invention provides a hollow frame having a stator mounted thereon,
A bracket having a heat radiating portion attached to an end of the frame, a housing provided on the bracket, a bearing fitted to the housing, and a rotor facing the stator via a gap are fixed. In a bearing cooling device for a rotating electric machine having a rotating shaft supported by the bearing, heat from the rotor side is supplied to an outside air side of the rotating shaft between an inner ring of the bearing and an outer periphery of the rotating shaft. A heat dissipating ring for dissipating heat is fitted. The heat dissipating ring has a configuration in which a U-shaped groove is provided on the end of the rotating shaft. The heat dissipating ring includes a first fin provided on the rotating shaft end side, provided on the bearing side, and inclined in a circumferential direction when viewed from the rotating shaft end side, and a first fin provided on the rotating shaft side. And a plurality of radial fins including a second fin inclined in the opposite direction. Further, a plurality of rods protruding into the rotor and the end of the rotating shaft are inserted into the heat radiation ring, and a heat insulating cover made of a low heat conductive material is provided in a penetrating portion between the rod and the heat radiation ring. Is fitted to the outer periphery of the rod. The heat dissipating ring may have a structure in which a member having low thermal conductivity is provided on the rotor-side surface or a mirror finish is applied.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view showing a first embodiment of the present invention. The bearing and frame surrounding structure of the rotating electric machine are almost the same as those in FIG. 5 used in the description of the conventional example. In the figure, 2 is a bracket attached to the end of the hollow frame 1 shown in FIG. 5, 21 is a housing provided on the bracket 2, 3 is a rotating shaft to which the rotor 30 shown in FIG. 5 is fixed, 4 is a bearing mounted on the inner periphery of the housing 21;
Is an outer ring of the bearing 4; 4b is an inner ring of the bearing 4; 5 is a heat dissipating ring provided between the inner ring 4b and the outer periphery of the rotary shaft 3; 5a is an inner ring support portion on which the heat dissipating ring 5 and the bearing inner ring 4b are fitted; Is a rotating shaft support portion on which the heat radiating ring 5 and the rotating shaft 3 are fitted;
Reference numeral 5c denotes an inner ring rotating shaft joint to which the inner ring supporting portion 5a and the rotating shaft supporting portion 5b are connected. Inner ring 4b of bearing 4 and rotating shaft 3
Inner ring 4 of the bearing via a heat radiating ring 5 fitted between
b, the rotating shaft 3 is rotatably supported.
In this structure, the distance from the shaft to the bearing 4 is large. With such a configuration, the heat of the rotating shaft 3 is transferred from the rotating shaft supporting portion 5b to the heat radiating ring 5 and a part thereof is
The heat is transmitted from the outside air side to the bearing 4 via the inner ring support 5a. Further, by disposing a member having low thermal conductivity on the inside air side surface of the heat radiating ring 5, the influence of heat from the inside air side can be reduced. Alternatively, if the inside air side surface of the heat radiating ring 5 is mirror-finished in place of the low heat conductive member, the surface absorptivity decreases, so that the influence of the inside air side radiation can be reduced. Further, the heat transfer amount from the rotating shaft to the bearing can be reduced by the heat radiating ring 5 configured as a heat radiating portion.

FIG. 2 is a side sectional view showing a second embodiment of the present invention. This is formed by cutting out a part of the heat radiation ring 5 shown in FIG. As described above, in the present embodiment, compared to the first embodiment, the heat dissipation ring 5 is provided with the groove, so that the heat dissipation area of the heat dissipation ring 5 to the outside air is increased.
With such a configuration, heat from the rotating shaft 3 is transmitted from the rotating shaft supporting portion 5b to the heat radiating ring 5, and a part thereof is
While the heat is radiated from the outside air side, the other components are transmitted to the bearing 4 through the inner ring support 5a through the inner ring rotating shaft joint 5c.
Therefore, since the heat radiating area from the heat radiating ring 5 to the outside air is increased, heat is radiated from the heat radiating ring 5 and the amount of heat transferred from the rotating shaft 3 to the bearing 4 can be reduced. In the same manner as in the first embodiment, a member having low thermal conductivity is provided on the inside air side surface of the heat radiating ring 5, or the inside air side surface is mirror-finished to generate heat or radiation from the inside air side. May be reduced.

FIG. 3A is a side sectional view showing a third embodiment of the present invention, and FIG. 3B is a front view of FIG. This is in addition to the configuration of the U-shaped groove provided on the outside air side of the heat radiating ring 5 shown in FIG. 2, and a position extending radially from the center of the shaft when viewed from the end of the rotating shaft on the bearing inner ring 4b side in the groove. First fin 51 provided so as to be inclined in the circumferential direction
And a second fin 52 provided on the outer peripheral side of the rotating shaft 3 so as to be inclined in a direction opposite to the first fin 51 at a position radially extending from the center of the shaft when viewed from the rotating shaft end side.
And the second fin 52 are arranged as a plurality of radial fins. Note that the fins may be provided on the rotation shaft end side of the heat radiating ring 5 shown in the first embodiment. Also, the cross-sectional shape of both fins should be a uniform rectangular cross-section from the mounting part in the U-shaped groove to the fin tip, or a rectangular cross-section tapering from the mounting part in the groove to the fin tip. It may be shaped. Further, the fin may have a cross-sectional shape having a curvature instead of the rectangular cross-sectional shape, and the extension of the fin attachment portion may not necessarily be arranged to pass through the center of the rotation axis. The fin mounting portion may be arranged such that both fins are close to each other or the distance between the fins is slightly apart. With such a configuration, the heat of the rotating shaft 3 is transmitted from the rotating shaft supporting portion 5b to the heat radiating ring 5, passes through the inner ring rotating shaft joining portion 5c through the inner ring supporting portion 5a while partially radiating heat to the outside air, and the bearing 4 Transmitted to In FIG. 8B, when the rotation direction of the rotating shaft 3 is, for example, clockwise, the outside air sucked from the outer first fins 51 is discharged from the inner second fins 52, and the rotation direction is reversed. In the clockwise direction, the outside air sucked from the second fin 52 is discharged from the first fin 51. Therefore, the first portion provided in the groove of the heat radiating ring 5
Fin 51, second fin 52, and heat radiating ring 5
By performing forced air cooling by the surface exposed to the outside air, heat radiation from the heat radiating ring 5 is promoted, and the amount of heat transfer from the rotating shaft 3 to the bearing 4 can be reduced. In addition, by reducing the amount of heat transfer to the bearing, the bearing temperature is reduced and the grease life is extended, and at the same time, the reduction of the bearing gap due to the thermal expansion of the bearing inner ring can be prevented, and rotation failure and burnout can be prevented. As in the first embodiment, a member having low thermal conductivity is disposed on the inside air side surface of the heat radiating ring 5, or the inside air side surface is mirror-finished so that heat or radiation from the inside air side is generated. It is even better to reduce the effect of

FIG. 4A is a side sectional view showing a fourth embodiment of the present invention, and FIG. 4B is a front view of FIG. In the figure, the heat radiating rod 53 is inserted inside the heat radiating ring 5 so as to protrude from both the rotor side and the rotating shaft end side of the heat radiating ring 5, and a plurality of heat radiating bars 53 are provided in the circumferential direction and the radial direction of the heat radiating ring 5. ing. The heat radiating rod 53 includes a heat absorbing portion 53a protruding toward the inside air, which is the rotor side of the heat radiating ring 5, and a heat transfer portion 53b, which is a penetrating portion of the heat radiating ring 5.
And a heat radiating portion 53c protruding toward the outside air, which is the end of the heat radiating ring 5 on the rotating shaft side.
a, 53b and 53c are integrated members. A cylindrical heat-insulating cover 54 made of a low heat conductive material is fitted on the outer periphery of the heat radiating rod 53 and accommodated in a penetrating portion between the heat radiating rod 53 and the heat radiating ring 5. The heat insulating cover 54 is preferably made of a low heat conductive material such as ceramic, rubber, or plastic. In such a configuration, the heat of the rotating shaft 3 is transmitted from the rotating shaft supporting portion 5b to the heat radiating ring 5, and a part of the heat is radiated to the outside air through the inner ring rotating shaft joining portion 5c via the inner ring supporting portion 5a. The process of transmitting the heat to the bearing 4 is substantially the same as that of the above-described embodiment, except that heat generated from the stator and the rotor is effectively radiated to the outside air. With this configuration, the heat on the inside air side is absorbed by the heat absorbing portion 53a of the heat radiating rod 53, transmitted to the heat radiating portion 53c via the heat transfer portion 53b insulated by the heat insulating cover 54, and radiated to the outside air. Note that the heat radiating rod 53 may have a configuration in which a U-shaped groove portion, which is partially cut out and provided on the outside air side of the heat radiating ring 5 shown in the second embodiment, penetrates. Further, similarly to the first embodiment, a member having low thermal conductivity is provided on the inside air side surface of the heat radiating ring 5, or the inside air side surface is mirror-finished so that heat or radiation from the inside air side is generated. It is even better to reduce the effect of

With the above-described means shown in the first to fourth embodiments, the distance between the rotating shaft and the bearing inner ring is increased by employing a heat radiating ring, and a heat radiating area is secured by a U-shaped groove or a fin. By doing so, the amount of heat transferred from the rotating shaft to the bearing inner ring can be reduced. Further, the heat radiation rod inserted into the heat radiation ring, a low heat conductive heat insulating material provided on the inside air side of the heat radiation ring, and a mirror-finished configuration can reduce the effects of radiation and heat from the heat generating portion. Therefore, the temperature rise of the bearing is small, and the life of the grease filled in the bearing is not reduced, and the bearing gap does not decrease due to thermal expansion.

[0010]

As described above, according to the present invention, a heat radiating ring, a fin or a heat radiating ring provided with a heat radiating rod is provided between the rotating shaft and the bearing, so that heat is effectively radiated to the outside air. The amount of heat transfer from the rotating shaft to the bearing can be reduced, without reducing the grease life due to the temperature rise of the bearing or reducing the bearing gap due to thermal expansion.
There is an effect of obtaining a highly reliable bearing cooling device for a rotating electric machine.

[Brief description of the 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. 3A is a side sectional view showing a third embodiment of the present invention, and FIG. 3B is a front view.

FIG. 4A is a side sectional view showing a fourth embodiment of the present invention, and FIG. 4B is a front view.

FIG. 5 is a side sectional view showing an entire configuration of a rotating electric machine as a conventional example.

[Explanation of symbols]

1: frame, 10: stator, 2: bracket, 21:
Housing, 3: rotating shaft, 30: rotor 4: bearing, 4a: outer ring, 4b: inner ring, 5: heat dissipation ring,
5a: inner ring supporting portion, 5b: rotating shaft supporting portion, 5c: inner ring rotating shaft joining portion, 51: first fin, 52: second fin, 53: heat radiating rod, 53a: heat absorbing portion, 53b: heat transfer portion ,
53c: heat radiation part, 54: heat insulation cover

Claims (6)

[Claims] 1. A hollow frame having a stator attached thereto, a bracket having a heat radiating portion attached to an end of the frame, a housing provided on the bracket, and fitted to the housing. A bearing cooling device for a rotating electrical machine, comprising: a bearing; and a rotating shaft supported by the bearing, the rotor being fixed to the stator with an air gap therebetween, wherein an inner ring of the bearing and an outer periphery of the rotating shaft are provided. A bearing cooling device for a rotating electric machine, wherein a heat radiating ring for radiating heat from the rotor side to the outside air side of the rotating shaft is fitted therebetween. 2. The bearing cooling device for a rotating electric machine according to claim 1, wherein the heat radiating ring has a U-shaped groove provided on an end side of the rotating shaft. 3. The heat dissipating ring is provided on the rotating shaft end side with a first fin provided on the bearing side and inclined in a circumferential direction when viewed from the rotating shaft end side, and provided on the rotating shaft side. 3. A plurality of radial fins comprising the first fin and a second fin inclined in the opposite direction are arranged.
A bearing cooling device for a rotating electric machine according to the above. 4. A plurality of rods projecting toward the rotor and the end of the rotating shaft are inserted into the heat radiation ring, and a low heat conductive material is inserted into a penetrating portion between the rod and the heat radiation ring. 3. The bearing cooling device for a rotating electric machine according to claim 1, wherein a heat insulating cover is fitted around the rod. 5. The bearing cooling device for a rotating electric machine according to claim 1, wherein the heat radiating ring has a member having low thermal conductivity disposed on the rotor side surface. 6. The bearing cooling device for a rotating electrical machine according to claim 1, wherein the heat radiating ring is mirror-finished on the rotor side surface.