JPH076682Y2 - Induction motor for vehicle - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an induction motor bracket for a railway vehicle driven by a variable voltage variable frequency inverter.

[0002]

2. Description of the Related Art Conventionally, steel or cast iron brackets have been used as brackets for induction motors for vehicles. Examples of insulation technology to prevent electrolytic corrosion include ceramic coating between the main motor frame and the mirror lid, cases where the mirror lid and bearing box are separated to insulate the two, and the outer ring outer surface of the bearing There is an example of applying alumina spraying. These are all applied to steel bracket electric motors, not to aluminum brackets.

FIG. 7 is a sectional view of the upper half of a conventional vehicle induction motor. 1 is a stator, 2 is a rotor, 3 is a rotor shaft, 4 is an iron drive side bracket, 5 is a roller bearing box, and 6 is a roller bearing box. Is a roller bearing, 7 is an iron anti-drive side bracket, 8 is a ball bearing box, and 9 is a ball bearing. In FIG. 7, the stator 1, the rotor 2, and the rotor 3 are conventional constituent parts of an electric motor, and therefore their explanations are omitted here. The iron drive side bracket 4, the roller bearing box 5, the roller bearing 6, the iron non-drive side bracket 7,
The ball bearing box 8 and the ball bearing 9 are the components around the bracket according to the present invention, that is, the bearing support.

[0004]

In such a bearing support part, since the bracket of the conventional vehicle induction motor is made of steel or cast iron, the mass of the entire motor becomes large, and thus the track is heavily burdened. It was a hindrance to the weight reduction and speedup of the given vehicle. In addition, although there have been some attempts around conventional main motor bearings, insulation against shaft current has not been put to practical use, and electrolytic corrosion of the bearing occurs, which hinders maintenance-free. The present invention has been made in view of the above-mentioned points, and an object thereof is to provide an induction motor for a vehicle that solves these problems of electrolytic corrosion while maintaining high reliability and high durability. It is a thing.

[0005]

[Means for Solving the Problems] A means for achieving the object is a bracket of an induction motor for a railway vehicle driven by a variable voltage variable frequency inverter, which is made of steel with a ceramics sprayed on the interface with an aluminum casting. The purpose is to obtain an aluminum alloy cast insulation bracket with a boss cast around it. That is, when the bracket is made of aluminum casting to reduce the weight of the vehicle induction motor, the bearing seat is likely to be scratched because it is soft when the bearing is inserted and removed during maintenance.
Therefore, the problem of maintenance is solved by casting a steel boss around this part, but if the insulating ceramic such as alumina is sprayed on the steel boss in advance, the bracket can be inserted from the armature shaft through the bearing. The current flowing therethrough can be interrupted to prevent electrolytic corrosion occurring in the bearing.

[0006]

[Operation] Electrolytic corrosion of the main motor bearing is caused by the generation of shaft voltage due to the imbalance of the magnetic circuit of the motor itself, the leakage current of the iron core and the magnetic frame by the converter such as an inverter, and the diversion of the return current of the rail.
It is the result of several complex phenomena such as impedance bond voltage drop. Since all of these run through the bearing, it is possible to prevent electrolytic corrosion by providing insulation around this. Since the present invention has a structure in which a steel boss is cast around an aluminum casting, an insulating ceramic is sprayed on the outer peripheral surface of the boss to prevent electrolytic corrosion.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to FIG. 7 which is a sectional view of the upper half of the induction motor for a vehicle described in the above-mentioned prior art.
FIG. 1 is an external view of the drive side bracket of the present invention, and FIG.
1 is a sectional view taken along the line of FIG. 1, FIG. 3 is a sectional view of a main portion of FIG. 2, FIG.
6 is a sectional view of the main part of FIG. 5, and 4'is a drive side bracket made of aluminum alloy,
7'is an aluminum alloy anti-drive side bracket, 10 is a drive side steel boss, 11 is an anti drive side steel boss, and 12 and 13 are ceramics of the present invention.

Therefore, the bearing of the electric motor is supported by the aluminum alloy drive side bracket 4'and the aluminum alloy anti-drive side bracket 7'of the present invention. The driving-side boss 10 and the non-driving-side steel boss 11 are cast around. Please note that these aluminum alloy brackets have
4'a and 7'a are provided. In addition, these brackets, as shown in FIGS.
An aluminum alloy cast insulation bracket is formed by casting a steel boss sprayed with ceramics. In the present invention,
When the bracket is cast, a steel boss sprayed with ceramics is heated to an appropriate temperature and then placed in a mold to form a cast doll. At this time, in order to improve the adhesion of the alumina to the steel bracket surface and the adhesion of the alumina and the molten aluminum alloy, for example, Ni-Al is sprayed to form a binder. That is, the steel boss (SS41) is first coated with Ni.
-Al sprayed to a thickness of about 50 μm, then alumina 10
Thermal spraying is performed to a thickness of 0 μm. After that, Ni-Al is sprayed again on the re-surface by about 50 μm. After the casting is complete, the product is cooled and finished grinding is performed. In the product thus obtained, the electrolytic corrosion is significantly reduced because the bearing itself is insulated from the bracket.

[0009]

As described above, according to the present invention, 15
Weight reduction per kg to 30 kg of electric motor is possible, which contributes to speeding up. In addition, electrolytic spraying of the ceramics prevents electrolytic corrosion of the bearings, which contributes to maintenance-free bearings, which was the only maintenance required for induction motors. The benefits of using induction motors as vehicle drive motors are immense. Becomes In addition, when the aluminum casting is rolled around, residual stress acts on the aluminum alloy casting during casting, and even if the temperature of the induction motor rises, there is no gap due to the difference in linear expansion coefficient, providing a highly reliable bracket. can do. In addition, by casting a steel boss around the fitting part with the bearing box, it is possible to prevent rust and scraping that occur when disassembling and assembling, and to maintain the durability of the fitting part due to vibration impact as before. it can. In this example, the aluminum boss is cast around the steel boss, but it goes without saying that the reverse is also included.

[0010]

[Brief description of drawings]

FIG. 1 is an outline view of a driving side bracket showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line of FIG.

3 is a cross-sectional view of the main part of FIG.

FIG. 4 is an outline view of a non-driving side bracket showing an embodiment of the present invention.

FIG. 5 is a sectional view taken along the line E-I of FIG. 4.

6 is a main cross-sectional view of FIG.

FIG. 7 is an upper half sectional view of a conventional vehicle induction motor.

[0011]

[Explanation of symbols]

 1 Stator 2 Rotor 3 Rotating shaft 4'Aluminum alloy drive side bracket 5 Roller bearing box 7'Aluminum alloy anti-drive side bracket 8 Ball bearing box 10 Drive side steel boss 11 Anti drive side steel boss 12 Insulation 13 Insulation

Claims (1)

[Scope of utility model registration request] 1. A bracket of an induction motor for a railway vehicle driven by an inverter of a variable voltage and a variable frequency, wherein a bracket made of an aluminum alloy casting having a detent is encircled with a steel boss sprayed with ceramics to surround the bracket and the electric machine. An induction motor for a vehicle, characterized in that the secondary shaft is insulated to prevent electrolytic corrosion of bearings and the like.