JPH05300698A - Ventilation cooling-type rotating electric machine - Google Patents

Abstract

PURPOSE:To provide a high-performance and highly reliable ventilation cooling- type rotating electric machine wherein ventilation cooling in the equipment is ensured and electrolytic corrosion of a bearing is prevented accurately despite a bypass duct is provided. CONSTITUTION:On both sides of a stator 5, bearing housings 6, 7 are installed through an electrolytic corrosion preventing insulator 21. On one bearing housing 6, a cooled water inlet 14 which allows air from a filter 15 to flow into one side of the machine and a bypass dust which allows part of the air from the filter 15 to flow into the other end of the machine are installed. In order to eliminate air coming inside through the bypass duct and air coming inside from one end of the machine altogether from the machine through the other end of the machine, an exhaust port 16 is installed. The bypass duct is installed apart from the stator 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ventilation cooling type rotary electric machine which is mainly used as a main motor of a railway vehicle.

[0002]

2. Description of the Related Art As shown in FIG. 4, a main electric motor for a railway vehicle (hereinafter simply referred to as a rotating electric machine) 1 is mounted between a bogie underframe 2 and an axle 3 of a vehicle via a mounting nose 4 for suspension. .. This rotating electrical machine 1 supports a rotor shaft 9a through a stator 5 having a stator core 5a and a stator coil 5b, and bearings 8 mounted on bearing housings 6 and 7 at both ends of the stator 5 to support the rotor 5a. And a rotor 9 rotatably provided inside thereof. A gear unit 11 is provided on a rotor shaft 9a protruding toward one end of the rotary electric machine 1 through a joint 10 to interlock with the axle 3 to drive the wheels 12 to rotate.

Such a rotary electric machine 1 cools the external air with a cooling air for the purpose of preventing heat generated inside the rotary electric machine (hereinafter simply referred to as "inside the machine") by energization and releasing it to the outside to prevent overheating in the machine. As a general example, a ventilation cooling type is adopted in which the air is taken in from one end side and discharged from the other end side. Even in this ventilation cooling type, the rotor shaft 9a is provided on the other end side in the machine.
There are many self-ventilated cooling types in which a fan 13 that rotates integrally with the is attached.

Further, in such a ventilation cooling type rotary electric machine,
If a large amount of dust-containing air (outside air) near the underfloor of a vehicle is taken into the machine as cooling air as it is, the dust adheres to and accumulates on the rotor and the like inside the machine, which causes a functional failure. As shown in FIG. 3, a filter 15 is attached on the cooling air inlet 14 provided in one bearing housing 6 of the rotary electric machine 1. In order to eliminate the need for cleaning and maintenance such as filter clogging, the filter 15 has recently adopted an automatic separation type filter (MF filter) that separates dust using maintenance-free centrifugal force and gravity. ing.

The automatic separation type filter 15 purifies the air sucked from the outside air intake port 15a by centrifugal action in the filter and automatically separates it into clean air A and dust-containing air B containing much dust. It is a composition. The clean air A is introduced from the cooling air introduction port 14 to one end side of the machine, is conducted to the other end side while cooling each part of the machine (taking heat away), and is discharged by the fan 13 to the exhaust port 16 More released to the outside. Further, the dust-containing air B is not directly passed through the inside of the machine but is passed through the bypass duct 17, and is introduced from the bypass duct 17 to the vicinity of the fan 13 on the other end side of the machine through the connection port 18,
From there, the air is discharged to the outside together with the clean air A that has cooled the inside of the machine by the discharge action of the fan 13.

On the other hand, in recent years, the electric corrosion of the bearing of the rotating electric machine due to the return current peculiar to the vehicle has increased, and countermeasures against it have become necessary. In other words, the electric current taken in from the overhead wire via the pantograph for energizing the electrical equipment of the vehicle is transmitted from the vehicle body through each electric device of the vehicle through the sliding brush 19 as shown in FIG. Flow to. However, a part of the current flows from the axle 3 through the bogie underframe 2 to the stator 5 from the mounting nose 4 of the rotary electric machine 1 as shown by an arrow C in FIG. , 7 to the bearings 8 and 8 and then from the bearing 8 to the axle 3 through the rotor shaft 9a, the joint 10 and the gear unit 11, and then from the axle 3 to the rail 20 via the wheels 12. It becomes a stray current. The stray current due to such a return current is a cause of causing electrolytic corrosion on the bearings 8, 8. Therefore, as the most effective method for preventing the electrolytic corrosion, the stator 5 and the bearing housings 6, 6 on both sides of the stator 5 are usually provided as shown in FIGS. An electrical insulator 21 is interposed between the electrical conductors 7 and 7 and in the middle of the bypass duct 17 for electrical insulation.

[0007]

By the way, in the above-mentioned conventional ventilation cooling type rotary electric machine, the automatic separation type filter 15 is attached for cooling the inside of the machine, and the dust-containing air B from this filter 15 is bypassed. While bypassing to the other end side in the machine through 17, the circuit of the stray current due to the return current is blocked by the insulator 21 in order to prevent the electrolytic corrosion of the bearings 8 and 8, but such an automatic separation type filter 15 is used. The electrolytic corrosion prevention structure provided with the following problems has the following problems.

First, as shown in FIG. 5, first, the filter 15 is used.
The dust D contained in the dust-containing air B gradually adheres and accumulates in the bypass duct 17 through which the dust-containing air B from the above flows, and based on the slight metal powder contained in this dust. The insulator 21 is short-circuited, and the electrical insulation between the stator 5 and the bearing housings 6 and 7 on both sides of the stator is lost. As a result, stray current due to retrace current flows to the bearings 8 and 8 There is a problem that causes corrosion.

Second, the bypass duct 1 made of a thin plate
It is quite difficult in structure to interpose the insulator 21 in the seam part in the middle of 7, and the insulator 21 is easily displaced or disengaged immediately due to traveling vibration or the like, and the reliability of the insulation performance is poor.

The present invention has been made in view of the above circumstances, and an object of the present invention is to achieve a very high performance because it is possible to surely prevent ventilation cooling in the machine and prevent electrolytic corrosion of the bearing, even though the bypass duct is provided. In order to provide a highly reliable draft cooling type rotating electric machine.

[0011]

In order to achieve the above object, a ventilation cooling type rotary electric machine of the present invention is provided with a bearing housing on both ends of a stator with an electrolytic corrosion preventing insulator interposed therebetween. The bearing housing of is provided with a cooling air inlet for allowing air from the filter to flow into one end of the machine, and a bypass duct for allowing a part of the air from the filter to flow into the other end of the machine. A structure is provided in which an exhaust port is provided for discharging the air that has come in through and the air that has passed through the inside of the machine from one end side to the outside of the machine from the other end side inside the machine, and the bypass duct is separated from the stator independently. It is characterized by being provided.

[0012]

According to the ventilation cooling type rotary electric machine having the above structure, the air from the filter flows into the one end of the inside of the machine through the cooling air introduction port of the one bearing housing, and a part of the air from the filter is bypassed. The air flowing into the other end of the machine via the bypass duct and the air coming from the one end to the inside of the machine are discharged together from the exhaust port to the outside of the other end of the machine. To be done. The ventilation of the air cools the inside of the machine to prevent overheating.

Further, since bearing housings are provided on both ends of the stator with an insulating material for preventing electrolytic corrosion, and the bypass duct is provided separately from the stator, the inside of the bypass duct is not provided. Even if dust adheres to and accumulates on the housing, it has never been said that an electrical short circuit will occur between the stator and the bearing housings on both sides, causing insulation breakdown, and the circuit for stray current due to return current can be maintained in the cutoff state. As a result, the electrolytic corrosion of the bearing can be reliably prevented.

In addition, since it is not necessary to provide a structurally difficult structure such as interposing an insulator in the middle of the bypass duct made of a thin plate, the assembling workability is good, and the ventilation cooling inside the machine and the electrolytic corrosion prevention of the bearing are prevented. It is a high-performance and highly reliable product that can reliably achieve both.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the ventilation cooling type rotary electric machine of the present invention will be described below with reference to FIG. In the figure, the same components as those shown in FIGS. 4 to 6 are designated by the same reference numerals to simplify the description.

First, similarly to the conventional case, the bearing housings 6 and 7 are provided on both ends of the stator 5 with the electrolytic corrosion preventing insulators 21 interposed therebetween. An automatic separation type filter (MF filter) 15 for separating dust by using maintenance-free centrifugal force is mounted on a cooling air inlet 14 provided in one of the bearing housings 6. The clean air A purified by the filter 15 is introduced as it is from the cooling air introduction port 14 to one end side of the inside of the machine, and is conducted to the other end side while cooling each part of the inside of the machine (taking away heat), and the fan 13 Is discharged to the outside through the exhaust port 16. Further, the dust-containing air B is not directly passed through the inside of the machine but is passed through the bypass duct 27, is introduced from the bypass duct 27 to the vicinity of the fan 13 on the other end side of the inside of the machine through the connection port 18, and is discharged by the fan 13 from there. It is discharged to the outside together with the clean air A coming while cooling the inside of the machine.

Here, the bypass duct 27 is provided separately from the stator 5. That is, FIG.
The conventional bypass duct 17 shown in FIG. 1 is constructed integrally with the stator 5 and the bearing housing 7 by affixing a laterally long channel material to the outer periphery thereof.
Includes a metal straight pipe 27a and an elbow pipe 27b, and one end of the straight pipe 27a is fitted and connected to the dust-containing air discharge port 15b of the filter 15 and the straight pipe 27a.
The other end of the elbow pipe 27b is fitted and connected, and the other end of the elbow pipe 27b is connected to the connection port 1 of the bearing housing 7 on the other end side.
8 is connected by welding or the like, and is arranged so as to straddle the bearing housings 6 and 7 on both sides, and is completely separated and independent from the stator 5.

Therefore, even if a stray current due to a return current flows from the bogie frame to the stator 5 via the mounting nose 4, it does not flow from the stator 5 to the bypass duct 27, and the stator 5 and both sides The bearing housings 6 and 7 are reliably electrically insulated by the insulator 21 to interrupt the circuit of the stray current. Further, even if dust adheres and deposits on the inner surface of the bypass duct 27 due to the dust-containing air from the filter 15, the insulator 21 that interrupts the circuit of the stray current is not polluted, and the stator 5 and the bearing housings 6 and 7 on both sides are not polluted. The short circuit between the bearings 8 and 8 will not cause dielectric breakdown, and the electrolytic corrosion of the bearings 8, 8 can be reliably prevented forever. In addition, since it is not necessary to provide a structurally difficult structure, such as interposing an insulator in the middle of the bypass duct 27 made of a thin plate, assembly workability is improved.

The clean air A from the filter 15 flows into one end of the bearing housing 6 through the cooling air inlet 14 and the dust-containing air B from the filter 15 is passed through the bypass duct 27. The dust-containing air B flowing into the other end side of the machine and coming through the bypass duct 27 and the air passing through the inside of the machine from the one end side together are exhausted to the outside of the machine from the other end side of the machine. Is released. Due to such ventilation of air, the inside of the machine is cooled substantially evenly and the overheat can be prevented.

FIG. 2 shows another embodiment of the present invention.
In this structure, the straight pipe 37a which is a part of the bypass duct 37 is joined to the dust-containing air discharge port 15b of the filter 15 and the elbow pipe 37b without being fitted to be removable. The straight pipe 37a is fitted to an electrically insulating mounting member 38, and the mounting member 38 is fixed to and supported by the stator 5 by a plurality of bolts 39. Thus, by loosening the bolt 39 and removing the straight pipe 37a together with the mounting member 38, it is possible to easily clean and remove the dust accumulated and deposited on the inner surface of the bypass duct 37.

FIG. 3 shows still another embodiment of the present invention, in which the straight pipe part which is a part of the bypass duct 47 is constituted by a combination of two straight pipes 48 and 49. These straight pipes 48 and 49 are connected to each other by an inner portion 48a and an outer portion 49a which are extendably fitted and connected to each other, and are connected to the dust-containing air discharge port 15b of the filter 15 and the elbow pipe 47b by screwing. There is.

Then, if the two straight pipes 48, 49 are rotated and the dust-containing air discharge port 15b of the filter 15 and the elbow pipe 47b are unscrewed, the two straight pipes 48, 49 are removed.
49 can be removed, and the dust adhering and accumulated on the inner surface of the bypass duct 47 can be easily cleaned and removed.

Further, in the present invention, in addition to the above-mentioned embodiment,
For example, a part of the straight pipe portion or the like of the bypass duct may be made of a flexible material such as a rubber tube, which facilitates the attachment / detachment and improves the assembling workability by simplifying the configuration.

Further, in the present invention, the straight pipe portion which is a part of the bypass duct in each of the above-described embodiments may be made of an insulating material, and by doing so, when the rotary electric machine rotates, Even a slight bearing current of the rotating electric machine itself caused by magnetic imbalance can be cut off, and the effect of preventing electrolytic corrosion of the bearing can be further improved.

Further, the ventilation cooling type rotary electric machine of the present invention is not limited to the self ventilation cooling type system in which a fan is built in the machine as described above, and a blower outside the rotary electric machine is used to blow cooling air such as outside air. Even in the forced ventilation cooling type in which the air is forcibly forced into the machine and ventilated, if the bypass duct is provided, it can be applied in the same manner as described above and the same effect can be obtained. The bypass duct is not only for bypassing the dust-containing air separated by the filter, but also on the leeward side (the other end side) inside the machine.
The purpose of this is to bypass a part of the cooling air in order to accelerate the cooling of, and it becomes possible to cool the entire inside of the machine almost evenly.

[0026]

Since the ventilation cooling type rotary electric machine of the present invention is configured as described above, it is possible to surely prevent ventilation cooling inside the machine and prevent electrolytic corrosion of the bearing even though it has a bypass duct. High performance and high reliability.

[Brief description of drawings]

FIG. 1 is a partially omitted sectional view showing an embodiment of a ventilation cooling type rotary electric machine of the present invention.

FIG. 2A is a sectional view of only a main part showing another embodiment of the ventilation cooling type rotary electric machine of the present invention, and FIG.
Sectional drawing which follows an X-ray.

FIG. 3 is a sectional view of only a main part showing still another embodiment of the ventilation cooling type rotary electric machine of the present invention.

FIG. 4 is a sectional view showing a general example of a state in which a ventilation cooling type rotating electric machine is mounted on a bogie of a vehicle.

FIG. 5 is a cross-sectional view of a conventional draft cooling type rotary electric machine with a part thereof omitted.

FIG. 6 is a cross-sectional view showing a joint structure between a stator and a bearing housing of a conventional ventilation cooling type rotating electric machine.

[Explanation of symbols]

5 ... Stator, 6, 7 ... Bearing housing, 14 ... Cooling air introducing port, 15 ... Filter, 16 ... Exhaust port, 21 ... Electrolytic corrosion preventing insulator, 27, 37, 47 ... Bypass duct.

Claims (5)

[Claims] 1. A bearing housing is provided on both ends of a stator with an insulator for preventing electrolytic corrosion interposed therebetween, and one of the bearing housings is provided with a cooling air inlet for allowing air from a filter to flow into one end of the machine. At the same time, a bypass duct that allows a part of the air from the filter to flow into the other end side of the machine is provided, and the air that has passed through this bypass duct and the air that has passed from the one side to the inside of the machine together A ventilation cooling type rotary electric machine having an exhaust port for discharging the air from the end side to the outside of the machine, wherein the bypass duct is provided separately from and independent of the stator. 2. The draft-cooled rotary electric machine according to claim 1, wherein the bypass duct is supported on the stator by an electrically insulating mounting member. 3. The ventilation cooling type rotary electric machine according to claim 1, wherein the bypass duct is made of an insulating material. 4. The ventilation cooling type rotary electric machine according to claim 1, wherein at least a part of the bypass duct is detachable. 5. The draft cooling type rotary electric machine according to claim 1, wherein the bypass duct is made of a flexible material.