JPH08149758A - Liquid leakage detector for electric rotating machine - Google Patents

Abstract

PURPOSE: To obtain a liquid-cooled electric rotating machine which can be operated continuously in safety day and night without requiring manual intervention. CONSTITUTION: In a liquid-cooled electric rotating machine applied with a mechanical seal unit 7, small quantity of cooling liquid leaked through a sealed part of the mechanical seal unit is introduced to a leaked liquid sump 3a provided for a predetermined plate of an outer cover 3. The leaked liquid is drained from a drain hole communicating the leaked liquid sump 3a through a drain pipe and sensed by means of a lead liquid detector 9 disposed in the way of the drain pipe. A threshold value is set for the quantity of leaked liquid to be drained and when a leaked liquid exceeding the threshold value is detected, the detector 9 delivers a signal for stopping the electric rotating machine through unattended operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid-cooled rotary electric machine equipped with a leak detector for detecting leak of cooling liquid.

[0002]

2. Description of the Related Art FIG. 2 is a partial cross-sectional view of a conventional liquid-cooled rotary electric machine. In FIG. 2, 1 is a bearing, 2 is a bearing housing, 3 is an outer cover, and 3c is a lubricating grease leak of the bearing 1. The oil drain groove 6 provided for preventing the above is a cooling liquid box, and a liquid inlet pipe 6a and a drain port 6b of a predetermined length are attached to the cooling liquid box 6. The cooling method of the rotor 4 is as follows. First, the liquid inlet 6c of the liquid inlet pipe 6a attached to the cooling liquid box 6
A hollow shaft 5 formed by mounting a rotor 4 on which cooling liquid flows from
It is discharged into a hole 5a having a predetermined length provided in the central portion of the.
The cooling liquid discharged into the hole 5a bounces at the end surface 5b of the hole and flows back through the gap 5c between the hole 5a of the hollow shaft and the outer circumference of the liquid inlet pipe 6a, and the inside of the cooling liquid box 6 from the opening 5d of the hole. It is discharged into the space A.

The rotor 4 is cooled by circulating the cooling liquid as described above. 7 is a mechanical seal unit,
The thrust direction sliding ring 7b of this unit is mounted on a mounting member 7a, and this mounting member 7a is mounted on the outer end surface 3d of the outer cover 3. On the other hand, mechanical seal
The rotating ring 7c of the unit 7 is attached to a mounting member 7d, and the mounting member 7d is attached to the outer periphery of the hollow shaft 5 extending to a predetermined position in the internal space A of the cooling liquid box 6, and the sliding ring 7b in the thrust direction. The contact seal surface B of the rotating ring 7c seals the cooling liquid to prevent the leakage of the cooling liquid.

For the slight leakage of the cooling liquid leaking from the contact seal surface B, a liquid leakage reservoir 3b is provided at a predetermined position of the outer cover 3 and is electrically connected to the liquid leakage reservoir 3b. From the drain hole 3b, the leaked liquid is discharged to the outside through a drainage pipe (not shown) or the like. With respect to the liquid leaked to the outside, the amount of the liquid leak is periodically measured with a measuring container (not shown), and it is caused by wear life or damage of the contact seal surface B of the mechanical seal unit 7. Checks and manages abnormal leaks.

[0005]

However, in the above-described conventional liquid leakage measurement and check means, when the liquid-cooled rotary electric machine is continuously operated day and night, the contact seal surface of the mechanical seal unit is worn and damaged. Therefore, it is not possible to know when an abnormal leak will occur, so it is necessary for a person to regularly measure the leak and check for any abnormalities.
It is extremely inefficient. Also, if an abnormal leak occurs in the absence of a person, some of the leaked coolant may enter the inside of the rotating electric machine, causing dielectric breakdown, or insufficient cooling of the rotor may cause burnout. There is a risk of The present invention was made in view of the above-mentioned points, and an object thereof is to provide a liquid-cooled rotary electric machine with a liquid leakage detector that can safely perform continuous operation day and night without human intervention. Especially.

[0006]

[Means for Solving the Problems] In other words, the means for achieving the object is, in a liquid-cooled rotary electric machine equipped with a mechanical seal unit, a slight cooling leaked from the seal portion of the mechanical seal unit. The leakage of the liquid is guided to the leakage reservoir provided on the predetermined plate of the outer cover, and the leakage is conducted through the drain hole through the drain pipe, etc. by conducting with the leakage reservoir, and the drainage is discharged. A leak detector is installed in the middle of the pipe to detect leaks, and a threshold value is set for the amount of leaked liquid. In the case of detection, the rotary electric machine is stopped unmanned by receiving a signal from the leak detector.

[0007]

The operation will be described together with the following embodiment. An embodiment of the present invention will be described in detail below with reference to the drawings.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The cooling means for the rotor 4 of a liquid-cooled rotary electric machine equipped with a mechanical seal unit 7 is exactly the same as in the conventional case shown in FIG. A detailed description will be given below focusing on the part. FIG. 1 is a partially enlarged sectional view of a liquid-cooled rotary electric machine showing an embodiment of the present invention. In FIG. 1, 7 is a mechanical seal unit, and a thrust direction sliding ring 7b of this unit is attached to a fitting 7a. The mounting bracket 7a is attached to the outer cover 3
Is attached to the outer end surface 3d. On the other hand, the rotary ring 7c of the mechanical seal unit 7 is mounted on a mounting metal fitting 7d, and this mounting metal fitting 7d is mounted on the outer periphery of the hollow shaft 5 extending to a predetermined position in the internal space A of the cooling liquid box 6, and the thrust The contact seal surface B of the direction sliding ring 7b and the rotating ring 7c seals the cooling liquid to prevent the leakage of the cooling liquid.

Further, for a slight leakage of the cooling liquid leaking from the contact seal surface B, a liquid leakage reservoir 3b is provided at a predetermined position of the outer cover 3 and a drain connected to the liquid leakage reservoir 3b. The leak liquid is discharged from the hole 3b through a drain pipe (not shown) or the like, and a leak detector 9 is provided in the middle of the drain pipe to detect the leak liquid. .

If a molten metal flow meter or a measuring element intrusion type flow meter is used as an example of the leak detector 9, the leak amount can be sensed as well as the leak amount can be sensed. Further, when a threshold value is set for the amount of leaked liquid and the leak detector 9 detects that the threshold value has been exceeded, rotation is performed by receiving an output signal from the leak detector 9. The electric machine can also be stopped by unmanned operation.

[0011]

As described above, according to the present invention, in a liquid-cooled rotary electric machine equipped with a mechanical seal unit, cooling liquid cooling generated by wear life or damage of the seal surface of the mechanical seal unit. It is possible to manage the check for abnormal leakage of liquid leakage in an unmanned state, and it is also possible to set a threshold value for the amount of liquid leakage and stop the rotating electric machine by unmanned operation. For this reason, the liquid-cooled rotary electric machine can be safely operated continuously day and night without any human intervention, which is extremely useful in practice.

[Brief description of drawings]

FIG. 1 is a partially enlarged sectional view of a liquid-cooled rotary electric machine showing an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of a liquid-cooled rotary electric machine showing a conventional embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bearing 2 Bearing housing 3 Outer cover 3a Leakage reservoir 3b Drain hole 3c Oil drain groove 3d Outer end face 4 Rotor 5 Hollow shaft 5a Hole 5b Hole end face 5c Gap 5d Hole opening 6 Coolant box 6a Liquid pipe 6b Drain port 6c Liquid inlet 7 Mechanical seal unit 7a Mounting bracket 7b Thrust direction sliding ring 7c Rotating ring 7d Mounting bracket A Internal space B Contact seal surface 9 Leak detector C Inside of rotating electric machine

Claims (3)

[Claims] 1. A liquid-cooled rotary electric machine equipped with a mechanical seal unit, wherein:
A small amount of cooling liquid leaking from the seal part of the unit
A liquid leak that is guided to a liquid leakage reservoir provided at a predetermined position on the outer cover, drains the liquid leakage through a drain hole that is connected to the liquid leakage reservoir, and senses the liquid drained through the drain hole. A leak detector for a rotating electric machine, comprising a detector. 2. The leak detector for a rotating electric machine according to claim 1, wherein a melt flow type flow meter or a measuring element insertion type flow meter is used as the leak detector. 3. An output of the leak detector when a threshold is set for the amount of leaked liquid discharged from the drain hole and the leak detector detects that the threshold has been exceeded. The leak detector of the rotating electric machine according to claim 1 or 2, wherein the rotating electric machine is stopped by a signal.