JPH11266566A - Cooling structure of outer rotor type generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce thermal stresses which are generated in a cooling pipe, by providing structure that can be easily deformed in an axial direction at the cooling pipe. SOLUTION: An elastic body 14 is provided at a part where a cooling pipe 13 is supported at an axle 1 so that extension in an axial direction cannot be constrained, thus preventing thermal stresses from being generated at the cooling pipe, since the relative displacement between the cooling pipe 13 and the axle 1 cannot be constrained due to thermal expansion. Or a flexible tube being made of a deformable material is provided halfway at the cooling pipe 13 or a curved part for absorbing the deformation of the cooling pipe 13 may be provided halfway at the cooling pipe 13. Also, by supporting the cooling pipe 13 with an elastic support 19 of the cooling pipe with an anti-vibration effect, damages due to shock loads can be prevented, thus improving the strength reliability of the cooling pipe.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling structure for an outer rotor type electric motor for railway vehicles, and more particularly to a water cooling structure.

[0002]

2. Description of the Related Art As a prior art of an outer rotor type electric motor cooled by using air, there is one disclosed in Japanese Patent Application Laid-Open No. 5-344680. In the cooling mechanism of this technology, air introduced into a motor through a hollow axle cools a stator core and a rotor inserted into the axle.

The air-cooled type has a problem in maintainability due to accumulation of dust taken in together with air. As a prior art of an outer rotor type electric motor cooled by using water, there is one disclosed in European Patent Office Publication No. 0623988A2.

[0004] In the cooling mechanism of this technology, a cooling hole through which cooling water flows is provided in an axle that rotatably supports an outer rotor, and cools a stator directly inserted into the axle. Further, cooling of this type of conventional outer rotor type electric motor will be described with reference to FIG.

In FIG. 6, a basic structure of an outer rotor type electric motor includes a cylinder 2 inserted into an outer periphery of an axle 1 having a cooling water passage 12 therein and supporting a vehicle body (not shown) in a non-rotating state. A wheel 3 rotatably supported via a bearing 5 fitted to one end of the outer periphery of the cylinder 2;
And a rotor frame 4 and a permanent magnet or cage type of an outer rotor type electric motor rotatably supported via a bearing 6 fitted to the other end of the outer periphery of the cylinder and rotatably driving the wheels 3. A rotor 11 includes a stator core 9 and a stator coil 8 which are disposed close to the inside of the permanent magnet or cage rotor 11 and are fitted around the outer periphery of a cylinder between the two bearings. .

Then, it is inserted into the inner surface of the stator core 9,
And a cooling jacket 7 inserted into the outer peripheral portion of the cylinder 2.
The cooling jacket 7 has a plurality of cooling water passages 12 therein communicating with the cooling water passages of the cylinder 2, and is fitted to the cooling jacket 7 with the cooling water passages 12 and the cooling water flowing through the cooling water passages 12. The structure is such that the inserted stator core 9 is cooled.

[0007]

In the conventional cooling structure of the outer rotor type motor using the cooling pipe, there is a problem that a thermal stress is generated in the cooling pipe due to a temperature difference between the cooling pipe and the axle.

It is an object of the present invention to provide a highly reliable cooling structure for supporting a cooling pipe so as not to restrain the elongation of the cooling pipe.

[0009]

In order to achieve the above object, a water cooling structure according to the present invention reduces thermal stress generated in a cooling pipe by providing a structure that is easily deformable in the axial direction. It was made.

Further, in this water cooling structure, the cooling pipe is supported by an elastic body having an anti-vibration effect so that breakage due to an impact load or the like can be prevented.

With such a structure, the thermal stress and vibration stress generated in the cooling pipe can be reduced, and the strength reliability of the cooling pipe can be improved.

[0012]

FIG. 1 shows an embodiment of the present invention.
An elastic body 14 is provided at a place where the cooling pipe 13 is supported on the axle so as not to restrict the axial elongation. In this case, since the relative displacement between the cooling pipe and the axle due to thermal expansion is not restricted, no thermal stress is generated in the cooling pipe. Further, by supporting the cooling pipe with the elastic support 19 of the cooling pipe having an anti-vibration effect, breakage due to an impact load or the like can be prevented.

FIG. 2 shows another embodiment of the present invention.
A flexible tube 15 made of a material that can be easily deformed is provided in the middle of the cooling pipe 13 so as not to restrict the elongation in the axial direction. In this case, since the flexible tube 15 absorbs the relative displacement between the cooling pipe and the axle due to thermal expansion, no thermal stress occurs in the cooling pipe.

In FIG. 3, a curved portion 16 for absorbing deformation of the cooling pipe is provided in the middle of the cooling pipe 13 so as not to restrain the extension in the axial direction. In this case, since the relative displacement between the cooling pipe and the axle caused by the thermal expansion is absorbed by the one-turn bending portion 16, no thermal stress is generated in the cooling pipe.

FIG. 4 shows an omega-shaped bend 17 having the same effect as the bend 16 in FIG.

FIG. 5 shows a case in which a bellows 18 which can be easily deformed is formed in the middle of the cooling pipe 13 so as to absorb the relative displacement due to heat so as not to restrain the elongation in the axial direction.

[0017]

As described in detail above, according to the water cooling structure of the outer rotor type electric motor of the present invention, the thermal stress generated in the cooling pipe by providing the cooling pipe with a structure that is easily deformed in the axial direction. In addition, a structure is provided in which the cooling pipe of the water cooling structure is supported by an elastic body having an anti-vibration effect, whereby damage due to an impact load or the like can be prevented, and the strength reliability of the cooling pipe is improved. be able to.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an outline of a cooling structure of an outer rotor type electric motor according to the present invention.

FIG. 2 is a sectional view showing an outline of a cooling structure of an outer rotor type electric motor according to another example of the present invention.

FIG. 3 is a sectional view showing an outline of a cooling structure of an outer rotor type electric motor according to another example of the present invention.

FIG. 4 is a sectional view showing an outline of a cooling structure of an outer rotor type electric motor according to another example of the present invention.

FIG. 5 is a sectional view showing an outline of a cooling structure of an outer rotor type electric motor according to another example of the present invention.

FIG. 6 is a sectional view showing an outline of a cooling structure of a conventional outer rotor type electric motor using cooling water.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Axle, 2 ... Cylinder, 3 ... Wheel, 4 ... Rotor frame, 5, 6
... bearing, 7 ... cooling jacket, 8 ... stator coil, 9 ...
Stator iron core, 10, 10 '... stator holder, 11 ... permanent magnet or cage rotor, 12 ... cooling water passage, 13 ... cooling pipe, 14 ... elastic body, 15 ... flexible tube, 16
... One-turn curved part, 17 ... Omega-shaped curved part, 18 ... Bellows, 19 ... Elastic support for cooling pipe.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H02K 17/16 H02K 17/16 Z

Claims (3)

[Claims] 1. A permanent magnet or a cage-shaped rotor inserted inside a cylinder rotatably connected to an outer periphery of an axle, and a stator provided with a plurality of cooling water passages inside the cylinder inserted into the outer periphery of an axle. In the outer rotor type electric motor in which the axle is hollow and the cooling pipe is provided, the cooling pipe can be freely deformed in the axial direction so as to absorb a difference in thermal expansion between the cooling pipe and the axle, but is fixed in a direction perpendicular to the axis. A cooling structure for an outer rotor type electric motor, wherein the cooling structure is supported by a structure to be used. 2. A cooling structure for an outer rotor type electric motor according to claim 1, wherein said cooling pipe is supported by an elastic body for suppressing vibration. 3. A cooling structure for an outer rotor type electric motor according to claim 1, wherein a curved portion having low rigidity is provided in a part of said cooling pipe to absorb deformation. Cooling structure.