JPH1014161A - Bearing cooling device for fully-closed rotary electric machines - Google Patents

Abstract

(57) Abstract: Provided is a bearing cooling device for a fully-closed rotary electric machine that can reduce the bearing temperature by sufficiently transferring heat transmitted from a rotor to a bearing to a rotating shaft end. A bracket (2) attached to an end of a frame (1), a housing (21) provided on the bracket (2), a bearing (4) housed in the housing (21), a rotating shaft (3) fixed to a rotor and supported by the bearing (4). An inner cover 22 that covers the rotor side of the bearing 4 and is attached to the housing 21 side;
A bearing cooling device for a fully-closed rotary electric machine having an outer cover 23 attached to the housing 21 side and covering the outside of the rotary shaft 3 has an inlet and an outlet in the axial direction from the end of the rotating shaft 3 toward the lower side of the inner cover 22. An axial ventilation passage 31 having a hole, a rotating shaft 3
Radial ventilation path 3 communicating with axial ventilation path 31 inside
And a cooling mechanism having a screw-shaped groove or a spiral coil for circulating air on at least one inner surface of the axial ventilation passage 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a bearing cooling device for improving cooling near a bearing fitted to a rotating shaft of a fully-closed rotary electric machine.

[0002]

2. Description of the Related Art Conventionally, a bearing cooling structure of a fully-closed type rotary electric machine has a structure in which a stator 10 is fixed inside a hollow cylindrical frame 1 as shown in FIG. Is provided with a bracket 2 at an end of the housing 21, and a housing 21 for accommodating a bearing 4 supporting the rotating shaft 3 is provided on the bracket 2.
Is provided. The rotor 30 is fixed to the rotating shaft 3. A bearing 4 fitted to the rotating shaft 3 and an inner cover 22 and an outer cover 23 covering the housing 21 are attached to the housing 21, and an oil drain 24 is provided on a surface of the inner cover 22 facing the rotating shaft 3. is there. At the center of the rotating shaft 3, an axial ventilation passage 31 is provided in the axial direction, and from the circumferential portion of the rotating shaft 3 which contacts the inner ring side of the bearing 4 and the lower side of the oil drain 24, the axial ventilation passage 31 is formed. There is disclosed a structure in which a radial ventilation passage 32 communicating with the bearing 4 is provided, and the outside air is brought into contact with the bearing 4 and a part of the oil drain 24 through the two ventilation passages to cool the bearing 4 (for example, an actual open flat 5-3613).
No. 1). Further, as shown in FIG. 13 as a second conventional example, a bearing 4 fitted to the rotating shaft 3 and an inner cover 22 and an outer cover 23 that cover the housing 21 are attached to a housing 21, and the back surface of the inner cover 22 is further attached. A cover ring 5 is provided on the rotating shaft 3 to cover the inner cover 22 and the housing 21.
A space room 7 is provided between the ring 5. An oil drain 24 is provided on a surface of the inner cover 22 facing the rotation shaft 3, and an axial ventilation passage 31 and a radial ventilation passage 32 are provided inside the rotation shaft 3. The bracket 2 is provided with a communication port 25 through which the space room 7 communicates with outside air, and the ring 5 is provided with a blade 6 having a fan function. With this configuration, with the rotation of the rotating shaft 3, the outside air is supplied to the axial ventilation passage 31, the radial ventilation passage 32, the space 7, and the communication port 25.
(See, for example, Japanese Patent Application Laid-Open No. 5-106666). Alternatively, as shown in FIG. 14 as a third conventional example, a bearing 4 fitted to the rotating shaft 3 and an inner cover 22 covering the housing 21 are attached to the housing 21, and
An outer cover 23 that covers the end of the rotating shaft 3 from 1 is attached. On the outer end face side of the bracket 2, an axial flow type external fan separate from the rotating electric machine main body is provided. An axial ventilation passage 31 is provided at the center of the rotating shaft 3 from the end, and a radial ventilation passage 32 communicating with the inner end surface of the bearing 4 covered with the inner cover 22 is provided at the back of the axial ventilation passage 31. Are provided radially. The housing 21 is provided with a communication port 21a, a space room 7a is provided between the inner cover 22 and the rotating shaft 3, and a space room 7b is provided between the outer cover 23, the bearing 4 and the rotating shaft 3. I do. With such a configuration, the air circulates from the axial ventilation passage 31 to the communication hole 21a and the outer cover 23 via the radial ventilation passage 32 and the inner cover 22 by the fan action with the rotation of the rotating shaft 3, A structure for cooling the bearing 5 is disclosed (for example, Japanese Patent Application Laid-Open No. 4-185260).

[0003]

However, in the prior art 1, since the air entering the axial ventilation path and the radial ventilation path does not circulate, the temperature of the air itself rises and the bearing temperature is sufficiently reduced. There was a problem that it could not be reduced. Further, in the conventional example 2, a seal is required in a gap between the ring 5 and the bracket 2 when forming a fully closed type, and power loss and heat generation due to friction of the seal portion are required.
There was a problem such as the necessity of maintenance of the seal portion. In addition, there is a problem that a space is taken inside the rotating electric machine, which hinders miniaturization. Alternatively, in the conventional example 3, since the circulating air does not communicate with the outside, the temperature of the circulating air itself increases, and there is a problem that the bearing temperature cannot be sufficiently reduced. Accordingly, an object of the present invention is to provide a highly reliable bearing cooling device for a fully-closed rotating electric machine which does not require a seal or space and can effectively reduce the bearing temperature.

[0004]

In order to solve the above-mentioned problems, the present invention provides 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 rotor supported by the bearing by fixing a rotor facing the stator via a gap. A bearing cooling device for a fully-closed rotary electric machine comprising: a shaft; 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. An axial ventilation path having an inlet and an exhaust hole in the axial direction from the end of the rotating shaft toward the lower side of the inner cover, and a radially extending passage communicating with the axial ventilation path inside the rotating shaft. And a cooling mechanism having a threaded groove or a spiral coil on at least one inner surface of the axial ventilation path. That. In addition, a hollow hole larger than the outer periphery of the axial ventilation passage is formed inside the rotary shaft, and a ventilation passage member having the cooling mechanism formed therein is fitted into the hollow hole. Also, in place of the ventilation path member, a spiral-shaped metal pipe formed by folding the ventilation path on the air inlet side and the exhaust hole side at the back of the ventilation path is provided, and the gap of the pipe is made of copper alloy or This is a configuration in which a member integrated with an aluminum alloy casting is provided. Further, an adapter having a radial hole communicating with the axial ventilation passage may be provided at an end of the rotating shaft, or an external air may be communicated with the rotating shaft between an end surface of the rotating shaft and the outer cover side. It is more preferable to provide a configuration in which radial holes are provided.

[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 of a bearing cooling device for a fully-closed rotating electric machine according to a first embodiment of the present invention, and FIG. 2 is a front view of a rotating shaft of FIG. The structure showing the bearing and frame structure around the rotating electric machine is almost the same as that of FIG. 10 used in the description of the conventional example. In the figure, a housing 21 is provided on a bracket 2, and a bearing 4 for rotatably supporting a rotating shaft 3 and an inner cover 22 and an outer cover 23 covering the housing 21 are attached. The rotating shaft 3 is provided with an axial ventilation passage 31 in the axial direction from the end to the rotor side through the lower side of the inner cover 22, and the axial ventilation passage 31 is an inlet for circulating air inside the rotating shaft 3. It has two openings, a pore and an exhaust hole. Further, a radial ventilation passage 32 is provided to communicate radially from the circumferential side of the rotating shaft 3 toward the depth of the axial ventilation passage 31, and the inner cover 22 is provided on the rotating shaft surface side of the radial ventilation passage 32. A blind lid 32a is provided so as not to contact the air on the back side.

FIG. 3 shows the structure of an axial ventilation passage. FIG. 7A shows a configuration in which at least one of the air passages of the air passage and the exhaust hole of the axial ventilation passage 31 is provided with a female thread 33 by forming a threaded groove inside the ventilation passage. A groove having a trapezoidal groove may be used instead of the groove. FIG. 2B shows a configuration in which a coil wound spirally is inserted into at least one of the ventilation passages 31 in the axial direction, so that air flows through the ventilation passage between the coils. In addition, instead of a coil wound in a spiral shape, a copper or aluminum alloy pipe formed by winding in a spiral shape is inserted into the air passage,
The gap between the pipe and the ventilation passage may be cast with an alloy. In this case, air flows through the pipe. With such a configuration, when the rotating shaft 3 is rotated, cold air outside the rotating electric machine is sucked into the air inlet of the axial ventilation passage 31 provided in the rotating shaft 3 with the rotation, and Radial ventilation passage 32 communicated with the section
Through the rotary shaft 3. Here, the air sucked toward the inner part of the rotary shaft 3 takes warm heat in the vicinity of the bearing 4 and the rotor side and circulates while being discharged to the exhaust hole side of the axial ventilation passage 31. The temperature of the bearing 4 fitted to the bearing 3 can be effectively reduced. Since the circulation of the air is performed only inside the rotating shaft 3 as described above, it does not leak into the rotating electric machine as shown in the conventional example, and the fully closed type can be easily configured. In both forward and reverse rotation directions of the rotating shaft 3, the effect of pumping the external air by the screw action of the screw portion or the helical portion has a large effect, and the flow in the ventilation passage is generated, so that the bearing temperature can be reduced. If spiral processing is performed on both the inlet and exhaust holes in opposite directions, the wind speed increases, and the bearing temperature can be further reduced.

[0007] Further, various arrangements of the axial ventilation path are conceivable. By increasing the number of the axial ventilation passages 31,
Can make the internal temperature in the radial direction uniform. For example, although not shown, when four axial ventilation passages are provided, one inlet hole and one exhaust hole may be connected, or four air holes may be connected simultaneously. FIG. 4 is a side sectional view of a bearing cooling device of a fully-closed rotating electric machine according to a second embodiment, and FIG. 5 is a front view of a rotating shaft of FIG. As shown in FIG.
One ventilation hole is provided, and four ventilation holes on the side of the exhaust hole are provided therearound, and these axial ventilation passages are communicated with a radial ventilation passage 32 provided in the inner part in the radial direction. hand,
The flow of the outside air is branched and circulated. With such a configuration, the axial ventilation passage 31 on the air inlet side is provided at the center of the rotating shaft 3, and the axial ventilation passage 31 on the exhaust hole side is provided therearound. The centrifugal force associated with the rotation of the air acts to further enhance the circulation of air.

FIG. 6 is a side sectional view of a bearing cooling device according to a third embodiment of the present invention. This is because the ventilation holes 31 and the ventilation holes of the axial ventilation passage 31 described in the first embodiment are provided obliquely in the axial direction from the end of the rotating shaft 3 so that the two ventilation passages communicate with each other at the back. Eliminates the need for radial ventilation paths,
In addition, the blind lid is unnecessary. With such a configuration, a radial ventilation path is not required, so that axial rigidity can be increased.

FIG. 7 is a side sectional view of a bearing cooling device showing a fourth embodiment of the present invention, and FIG. 8 is a front view of a rotating shaft of FIG. In FIG. 7, compared to the first embodiment, a cooling mechanism including an axial ventilation passage 31 and a radial ventilation passage 32 is provided on the rotor side from the end of the rotating shaft 3 to below the inner cover 22. Although the configuration is the same, the configuration is different in that a hollow hole 35 is formed inside the rotating shaft 3 and a cylindrical ventilation path member 36 having the cooling mechanism housed therein is fitted into the hollow hole 35. The ventilation path member 36 is slightly larger than the inner diameter of the hollow hole 35 and is inserted by shrink fitting or the like. Since the structure including such a ventilation path member has no notch in the circumferential surface of the rotating shaft, there is an advantage that the shaft rigidity of the rotating shaft can be kept high and there is no need to provide a blind cover. In addition, in such a configuration in which the cooling mechanism is provided inside the ventilation path member, at least one of the ventilation paths of the intake hole and the exhaust hole of the axial ventilation path 31 is configured as shown in FIG. The configuration is such that a ventilation path for generating an air flow is ensured by, for example, thread-shaped or trapezoidal groove processing or insertion of a coil formed in a spiral shape.

FIG. 9 shows the structure of an air passage provided inside the air passage member 36 as an example in which the air passage is variously changed. As shown in FIG. 3A, reference numeral 37 denotes a metal pipe made of a copper alloy or an aluminum alloy. The pipe 37 is formed by turning the air inlet side and the air outlet side at the back of the ventilation path member 36 and spirally winding them. ing. On the other hand, the ventilation path member 36 is formed as a cylindrical body by casting a copper alloy or an aluminum alloy into a gap between the pipe 37 and the rotating shaft 3 so that the opening of the pipe 37 is on the end side of the rotating shaft 3. It is inserted into the hollow hole 35 by shrink fitting. With such a configuration, the spiral pipe 3 provided in the ventilation path member 36 so as to be located at the end of the rotating shaft 3
7, the openings of the air inlet and exhaust holes secure the flow path of the external air, so that the cool air outside the rotary electric machine can pass through the ventilation path member 36 inserted into the rotary shaft 3 as the rotary shaft 3 rotates.
The air is sucked from the air inlet side, and flows spirally inside the pipe 37 toward the back of the ventilation path member 36. The air sucked into the rear part of the ventilation path member 36 takes warm heat near the bearing 4 and on the rotor side, and is discharged to the exhaust hole side at the end of the rotating shaft 3 and circulates. The temperature of the bearing 4 can be reduced effectively. FIG.
As shown in FIG. 3B, the pipe 37 is spirally wound from the end of the rotating shaft to form a circular pipe, and then the air inlet side and the exhaust side are turned back at the back of the ventilation path member 36, A double circular tube may be formed by spirally winding at a reverse pitch.

The rotating electric machine provided with the bearing cooling device described above is used for belt hanging, but in the case of a rotating electric machine for directly connecting the device to the end of the rotating shaft, the axial ventilation at the end of the rotating shaft 3 is used. Road 31 cannot communicate with the outside air. FIG. 10 shows a side sectional view of a bearing cooling device shown as a fifth embodiment of the present invention, in which a radial ventilation passage 32 is connected to the outside of the axial ventilation passage 31 for communication with outside air. May be provided to communicate with the outside air. FIG. 11 shows a side sectional view of a bearing cooling device shown as a sixth embodiment of the present invention. When an adapter 9 having a radial ventilation path at the end of the rotating shaft 3 is used, The rotating shaft 3 can be used for both a belt hanging use and a device directly connected use, and the shaft rigidity can be increased.

By the above means, the bearing cooling device operates as follows. (1) An axial ventilation path having an intake hole and an exhaust hole in the axial direction from the end of the rotation shaft toward the lower side of the inner cover, and a radius provided in the radial direction communicating with the axial ventilation passage inside the rotation shaft. A cooling mechanism having a screw-shaped groove or a spiral coil that circulates air on at least one inner surface of the axial ventilation path, so that cold air outside the rotating electric machine is It circulates through the inside of the rotating shaft with the rotation, and the temperature of the bearing fitted to the rotating shaft can be effectively lowered. Therefore, since there is no air leakage inside the rotating electric machine, it is possible to easily configure a fully closed type that does not require a seal and does not require a new space of the present apparatus. (2) Since the cooling mechanism is provided inside the ventilation passage member fitted into the hollow hole at the end of the rotating shaft, the circumferential surface of the rotating shaft has no notch, and the shaft rigidity can be kept high. (3) Since an adapter having a radial ventilation path is provided at the end of the rotating shaft, a single rotating shaft can be used for both a belt hanging application and a device direct connection, and has a high shaft rigidity. Can be enhanced.

[0013]

As described above, according to the present invention, the axial ventilation passage having the air inlet and the exhaust hole from the end of the rotating shaft toward the lower side of the inner cover and the radial direction communicating with the inner part at the back portion. As it has a cooling mechanism that secures ventilation passages and has screw-shaped grooves that cause air to flow in the axial ventilation passages,
There is an effect of obtaining a highly reliable bearing cooling device for a fully-closed rotary electric machine that does not require a seal or space and can effectively reduce the bearing temperature. In addition, when a ventilation path member having a cooling mechanism inside is inserted into a hollow hole drilled at the end of the rotating shaft, a surface notch can be eliminated, thereby maintaining a highly rigid shaft structure. There is also an effect of obtaining a possible bearing cooling device for a fully-closed rotary 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 front view of a rotation shaft of FIG. 1;

FIG. 3 is a side sectional view showing a structure of an axial ventilation passage.

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

FIG. 5 is a front view of the rotation shaft of FIG. 4;

FIG. 6 is a side sectional view showing a third embodiment of the present invention.

FIG. 7 is a side sectional view showing a fourth embodiment of the present invention.

FIG. 8 is a front view of FIG. 7;

FIG. 9 is a side sectional view showing a structure of a ventilation path member.

FIG. 10 is a side sectional view showing a fifth embodiment of the present invention.

FIG. 11 is a side sectional view showing a sixth embodiment of the present invention.

FIG. 12 is a side sectional view showing a first conventional example.

FIG. 13 is a side sectional view showing a second conventional example.

FIG. 14 is a side sectional view showing a third conventional example.

[Explanation of symbols]

1: frame, 10: stator, 2: bracket, 21:
Housing, 21a: communication port, 22: inner cover, 2
3: outer cover, 24: oil drain, 25: communication port, 3: rotating shaft, 30: rotor, 31: axial ventilation path, 31a: blind lid, 32: radial ventilation path, 32a: blind lid, 33: female screw, 34: coil, 35: hollow hole, 36: ventilation member,
37: metal pipe, 38: alloy casting, 4: bearing, 5:
Ring, 6: feather, 7: space room, 7a: space room, 7
b: Space room, 8: Outside fan, 9: Adapter

Claims (5)

[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 rotating shaft supported by the bearing and fixed to the rotor opposed thereto, an inner cover covering the rotor side of the bearing and attached to the housing side, and covering an outer side of the bearing and attached to the housing side. A bearing cooling device for a fully-closed rotary electric machine having an outer cover, wherein: an axial ventilation path having an air inlet and an exhaust hole in an axial direction from an end of the rotating shaft toward a lower side of the inner cover; A radial ventilation path provided in a radial direction communicating with the axial ventilation path inside the shaft, and a threaded groove or a spiral in at least one inner surface of the axial ventilation path Bearing cooling apparatus totally enclosed type rotational electrical machine, characterized in that a cooling mechanism having a Jo coil. 2. A hollow hole larger than the outer periphery of the axial ventilation passage is formed inside the rotary shaft, and a ventilation passage member having the cooling mechanism formed therein is fitted into the hollow hole. A bearing cooling device for a fully-closed rotary electric machine as described in the above. 3. A spiral-shaped metal pipe formed by folding the ventilation path on the air inlet side and the exhaust hole side at the back of the ventilation path instead of the ventilation path member. The bearing cooling device for a fully-closed rotating electric machine according to claim 1 or 2, further comprising a member integrated by casting of a copper alloy or an aluminum alloy. 4. An adapter having a radial hole communicating with the axial ventilation path is provided at an end of the rotating shaft.
4. The bearing cooling device for a fully-closed rotary electric machine according to any one of items 1 to 3. 5. The fully closed structure according to claim 1, wherein a radial hole is provided between the end of the rotating shaft and the outer cover side for communicating with the outside air to the rotating shaft. Cooling device for rotary electric machines.