JP2002078282A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary electric machine which accomplishes elongation of maintenance interval by reducing temperature of a roller bearing during the operation. SOLUTION: The rotary electric machine has a fan 18, which discharges cooling air which has cooled each part inside the machine from a cooling air exhaust outlet 2c of a frame 2, is coupled with a rotary shaft 9, and a bracket 10, which fixes a load-side roller bearing 12 which supports the rotary shaft 9 on the load-side end part of the frame 2, is assembled near the outer wall of a shroud 18a of the fan 18. A fin 18d which makes a fan action by having a prescribed space with the inner wall of the bracket 10 is fixed to the outer wall of the shroud 18a, and an air hole 10a which connects to a space on the bore side of the fin 18d is disposed near the fixing part of tie load-side roller bearing 12 on the bracket 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating electric machine suitable as a main motor for railway vehicles, which improves the cooling effect of rolling bearings, reduces the operating temperature and extends the maintenance interval of lubricating oil.

[0002]

2. Description of the Related Art A main motor for a railway vehicle is mounted in a narrow space between a vehicle body and a rail. In addition, various wirings and pipes are complicated around the motor, and the main motor is exposed to a drastic change in the outside air temperature, causing dust and brake wear. In many cases, it is placed in an environment where maintenance and inspection cannot be easily performed, such as exposure to powder or raindrops.
On-site demands for installation of motors with long maintenance intervals are persistent.

[0003] In order to meet this demand, a conventional main induction motor for a railway vehicle for reducing the temperature of a load-side rolling bearing, in particular, in which the arrangement condition is severe, is shown in a sectional side view of FIG. In FIG. 5, reference numeral 1 denotes a main induction motor for a railway vehicle, which is constituted by the following elements. 2
Is a cylindrical frame with a bottom, a bottomed portion 2a is provided on the opposite side of the load, a cooling air inlet 2b is opened, and a cooling air outlet 2c is opened on the load side. A stator core 3 is provided on the inner periphery of the frame 2 in a stacked manner.
The stator winding 4 is wound in the slot (not shown). Reference numeral 5 denotes a rotor core laminated and fitted on the rotating shaft 9, which has an air hole 5 a penetrating in the axial direction, and a rotor bar 6 in a slot (not shown) of the rotor core 5. It is inserted and both ends are short-circuited by the end ring 7. The inner diameter of the stator core 3 and the outer diameter of the rotor core 5 are separated by a required gap g. Reference numeral 8 denotes a fan fitted on the rotating shaft 9, which is composed of a shroud 8a that forms a main wall and guides exhaust, a guide ring 8b that increases the fan effect and guides exhaust, and a blade 8c that functions as a fan. .

Reference numeral 10 denotes a bracket mounted on the opening side of the frame 2. A ventilation hole 10a for ventilation is penetrated near the bearing mounting portion on the side surface thereof, and a load-side rolling bearing 12 is mounted on the central opening. ing. Reference numeral 11 denotes an anti-load side rolling bearing mounted on the center opening of the bottomed portion 2a of the frame 2, and the rotating shaft 9 is provided with each rolling bearing 11,
12 rotatably supported. Note that 11a,
12a is an inner ring of each rolling bearing 11, 12, 11b, 12
b is an outer ring. Reference numeral 13 denotes a shield plate which is attached to the inner periphery of the frame 2 with a required gap from the outer diameter of the guide ring 8b to guide exhaust air to prevent backflow, and 14 denotes a frame 2, the bracket 10 and the shield plate on the outer diameter side of the fan 8. 1
An exhaust space 15 surrounded by 3 is a cooling air introduction cover which is attached to the frame 2 above the cooling air introduction port 2b and introduces cooling air.

[0005] In the main induction motor 1 for a railway vehicle configured as described above, when a voltage is applied to the stator winding 4, a rotating magnetic field is generated and the rotor bar 6 is driven by electromagnetic induction.
, A rotating force is generated, and the rotating shaft 9 rotates in a predetermined direction together with the rotor core 5. Then, cooling air is sucked in from the cooling air introduction cover 15 by the suction force of the fan 8, and is introduced into the machine from the cooling air introduction port 2b as shown by a solid line arrow to indicate the opposite end of the stator winding 4 on the non-load side. And the other through the gap g, the other through the air hole 5a of the rotor core 5, the Joule heat generated in the stator winding 4, the rotor bar 6, the end ring 7, etc., respectively, and the stator core 3 The heat is absorbed by the iron loss generated in the rotor core 5 or the frictional heat generated by rotation, and is merged. The combined heat is discharged to the exhaust space 14 by the fan 8 and discharged to the outside of the cooling air outlet 2c. In this case, the suction force of the fan 8 causes the bracket 10
The outside air is also sucked from the ventilation hole 10a as indicated by the flow indicated by the solid line, the bearing loss heat is absorbed from the jacket near the mounting portion of the load-side rolling bearing 12, the bearing temperature is reduced, and the cooling air is exhausted by the fan 8. The air is exhausted from the outlet 2c to the outside of the machine.

[0006]

However, if the opening area of the cooling air discharge port 2c and the hydrodynamic structure around the exhaust space 14 are not appropriate, the air discharged into the exhaust space 14 by the fan 8 easily goes to the outside. It is not discharged and the internal pressure of the exhaust space 14 increases. Therefore, the high-temperature air discharged into the exhaust space 14 flows backward as indicated by a dashed line arrow and is discharged to the outside through the through hole 10a of the bracket 10, and heats the jacket of the mounting portion of the load-side rolling bearing 12. However, the temperature of the load-side rolling bearing 12 is increased. On the other hand, recently, in a main induction motor for a railway vehicle having a small size and a large capacity, a loss per heat radiation area of a loss generating portion is large, and an air temperature after cooling has a considerably high value. Even in this case, the anti-load side rolling bearing 1
1 is cooled by the low-temperature cooling air introduced from the cooling air inlet 2b, so that the temperature rise is maintained at a level without any problem, but a part of the high-temperature air discharged into the exhaust space 14 by the fan 8 flows backward. When it is discharged from the through hole 10a of the bracket 10, the effect on the temperature rise of the load-side rolling bearing 12 cannot be ignored. In this case, the load-side rolling bearing 1
2, the temperature of the bearing rises, the deterioration of the used lubricating oil is accelerated, and it becomes necessary to frequently carry out maintenance and inspection of the bearing, which may cause a problem that the maintenance interval cannot be extended.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and by improving a simple cooling structure, it is possible to easily reduce the temperature during operation of rolling bearings, including existing machines, and maintain the rolling bearings. It is an object of the present invention to provide a rotating electric machine suitable for railway vehicles, in which the interval can be lengthened.

[0008]

A rotating electric machine according to the present invention comprises:
In a rotating electric machine having a built-in fan that sucks and discharges cooling air for cooling various parts in the machine, and a rolling bearing and a bracket to which the rolling bearing is mounted near the fan, a required space is provided between the inner wall of the bracket and the rotating bearing. Fins that act as a fan with a gap are provided on the outer wall of the fan, and a communicating portion that communicates with the outside air from a space on the inner diameter side of the fin is provided on a mounting member of the rolling bearing. Further, the communication portion is a ventilation hole penetrating through a side wall of the bracket near the rolling bearing mounting portion. Further, the communication portion is a ventilation groove provided in the rolling bearing fitting portion of the rotating shaft. Further, the communication portion is provided at a mounting portion of the load-side rolling bearing.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional side view of a main induction motor for a railway vehicle according to Embodiment 1 of the present invention, and FIG. 2 is a front view as viewed from a load side in FIG. In the drawings, the same reference numerals indicate the same or equivalent components as those in the conventional example. same as below. 1 and 2, reference numeral 21 denotes a main induction motor for a railway vehicle, 18 denotes a fan fitted on the rotating shaft 9, and is disposed between the shroud 18 a, the guide ring 18 b, the blade 8 c, and the inner wall of the bracket 10. It is formed of eight fins 18d that function as fans and are provided at equal intervals on the outer wall of the shroud 18a with a required gap.

When a voltage is applied to the stator winding 4 and the rotating shaft 9 rotates in the main induction motor 21 for a railway vehicle configured as described above, the flow is indicated by a solid arrow as shown in FIG.
Cooling air is sucked in from the cooling air inlet 2b by the suction force of the fan 18 and is introduced into the machine to cool the opposite end of the stator winding 4 on the non-load side, one through the gap g and the other through the rotor core. 5, Joule heat generated in the stator winding 4, the rotor bar 6, the end ring 7, etc. through the wind hole 5a, heat generated by iron loss generated in the stator core 3 and the rotor core 5, or frictional heat generated by rotation. Are absorbed and merged, and are discharged to the exhaust space 14 by the fan 18 and the cooling air discharge port 2
The air is exhausted from c. In this case, due to the fan action of the fins 18d, the outside air is reliably sucked from the ventilation holes 10a (provided at four locations at the same pitch) penetrating through the side wall of the bracket 10 as shown by the flow indicated by the solid line arrow, and the load-side rolling bearing is provided. The bearing loss heat is absorbed from the jacket of the mounting portion 12 to reduce the bearing temperature, and is exhausted from the cooling air outlet 2c to the outside of the machine. That is, in this case, the high-temperature exhaust gas discharged into the exhaust space 14 by the blade 8c is supplied to the shroud 18a.
Flows back into the space between the outer side wall of the bracket 10 and the inner side wall of the bracket 10 and is discharged from the ventilation hole 10a and
There is no occurrence of heating the jacket of the mounting portion and increasing the temperature of the load-side rolling bearing 12.

Embodiment 2 FIG. 3 is a sectional side view of a main induction motor for a railway vehicle according to Embodiment 2 of the present invention, and FIG. 4 is a front view as viewed from the load side in FIG. 3 and 4, reference numeral 31 denotes a main induction motor for a railway vehicle;
Reference numeral 0 denotes a bracket, and other configurations in which the ventilation holes are not penetrated are the same as those in the first embodiment. 1
Reference numeral 9 denotes a rotating shaft, and a ventilation groove 19a communicating with the outside air from a space between the outer wall of the shroud 18a of the fan 18 and the inner wall of the bracket 30 has a uniform pitch at the fitting portion of the load-side rolling bearing 12. Are provided at four locations. Other configurations are the same as those in the first embodiment. Normally, the temperature of the load-side rolling bearing 12 during operation is higher in the inner ring 12a fitted to the rotating shaft 19 than in the outer ring 12b attached to the bracket 30. Therefore, in order to lower the temperature of the load-side rolling bearing 12, it is extremely effective to lower the temperature of the inner ring 12a, and the invention of the second embodiment has been made by paying attention to this point.

In the main induction motor 31 for a railway vehicle configured as described above, when a voltage is applied to the stator winding 4 and the rotating shaft 19 rotates, similar to the first embodiment,
The fan 18 generates a flow of cooling air in the machine indicated by an arrow, and cools each part. However, the fan action of the fins 18d also introduces outside air through the ventilation groove 19a provided in the rotating shaft 19, and the load-side rolling bearing 12 inner rings 12
a to cool the outer wall of the shroud 18a and the bracket 3
The air is exhausted from the cooling air outlet 2c to the outside as shown by a solid line arrow through the space between the inner wall and the inner wall of the cooling air. As a result, the operating temperature of the load-side rolling bearing 12 can be further reduced.

In the first and second embodiments,
Although the configuration in which the fan 18 is arranged on the load side is shown, the fan 18 may be arranged on the non-load side in the same manner. In addition, the configuration in which the bracket 10 provided with the ventilation hole 10a and the rotation shaft 19 provided with the ventilation groove 19a are separately applied has been described.
It is needless to say that the ventilation hole 10a and the ventilation groove 19a may be provided together. Although the main induction motor 1 for a railway vehicle has an open jacket, the present invention is not limited to this and can be similarly applied to a fully-closed internal cooling type.
Furthermore, although the description has been given of the induction motor, it goes without saying that other rotary electric machines such as a synchronous machine or a DC machine can be similarly applied as long as a similar ventilation structure is adopted.

[0014]

The present invention is configured as described above.
The following effects are obtained. Fins are provided on the outer wall of the fan incorporated in the rotating electric machine and have a required clearance between the inner wall of the bracket and the inner wall of the bracket. Since the communicating portion communicating with the bearing is provided, the rolling bearing is cooled by the outside air introduced from the communicating portion, the operating temperature is reduced, the aging of the bearing lubricating oil is reduced, and the maintenance interval can be lengthened. In addition, since a communication hole is provided in the rotating shaft to which the rolling bearing is fitted, the inner ring, which is the hottest in the rolling bearing, is effectively cooled by the outside air passing through the ventilation groove, further reducing the operating temperature of the rolling bearing. In addition, deterioration of bearing lubricating oil over time can be reduced, and maintenance intervals can be lengthened.

Further, since the communication hole is provided in the mounting portion of the load-side rolling bearing, the maintenance interval of the load-side rolling bearing, which is difficult to disassemble and inspect, is extended, so that the opportunity for disassembly and assembly during maintenance is reduced. The merit of reducing labor is great.

[Brief description of the drawings]

FIG. 1 is a sectional side view of a main induction motor for a railway vehicle according to a first embodiment of the present invention.

FIG. 2 is a front view as viewed from a load side in FIG. 1;

FIG. 3 is a sectional side view of a main induction motor for a railway vehicle according to a second embodiment of the present invention.

FIG. 4 is a front view as seen from the load side in FIG. 3;

FIG. 5 is a sectional side view of a conventional main induction motor for a railway vehicle.

[Explanation of symbols]

2, frame 2c; cooling air outlets 9, 19; rotating shafts 10, 30; brackets 10a; ventilation holes 12; load-side rolling bearings 12a; inner rings 12b; outer rings 18;
Shroud 18d; Fin 19a; Vent groove

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H605 AA01 BB05 CC01 CC02 CC03 CC04 DD07 DD11 DD12 DD31 EB10 EB17 5H609 BB02 BB18 PP02 PP11 QQ02 QQ13 QQ14 QQ18 RR03 RR10 RR18 RR22 RR24 RR27 RR33 RR35 RR36 RR36

Claims (4)

[Claims] 1. A rotating electric machine having a built-in fan for sucking and discharging cooling air for cooling various parts inside a machine, and a rolling bearing and a bracket to which the rolling bearing is mounted are disposed near the fan, wherein the inside of the bracket is provided. Fins acting as a fan with a required gap between the fins and the wall are provided on the outer wall of the fan, and a communication portion communicating from the space on the inner diameter side of the fins to the outside air is provided on the mounting member of the rolling bearing. A rotating electric machine characterized by the above-mentioned. 2. The rotating electric machine according to claim 1, wherein the communication portion is a ventilation hole that penetrates a side wall of the bracket near the rolling bearing mounting portion. 3. The rotating electric machine according to claim 1, wherein the communication portion is a ventilation groove provided in a rolling bearing fitting portion of the rotating shaft. 4. The communication part according to claim 1, wherein the communication part is provided on a mounting part of the load-side rolling bearing.
The rotating electric machine according to claim 3.