JPH09308189A - Turbo type air compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform the cooling of a high-speed motor surely without causing vibration, etc., by equipping this compressor with a cooling line which introduces a part of the compressed air cooled with a cooler into the casing of a motor. SOLUTION: A first compressor 21 is directly coupled with one end of the rotor shaft 5 of a motor, and a second compressor 22 is directly coupled with the other end, and compressed air which has come to high temperature, being compressed in two stages is cooled with an after cooler 13. A part of this cooled compressed air is introduced into the casing 8 of a motor 1 through a cooling line 14 so as to cool a rotor 4 or a stator 6. Hereby, a fan becomes needless, and the rotor shaft 5 can be shortened, and the occurrence of vibration can be prevented. Moreover, the inside of the motor casing 8 can be cooled surely by using the air cooled with an after cooler 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turbo type air compressor which is directly connected to a rotor shaft of an electric motor and driven.

[0002]

2. Description of the Related Art A turbo type air compressor is driven at tens of thousands of revolutions per minute. A turbine or an electric motor driven by the exhaust gas of the engine is used as a drive source. In the case of a turbine, the compressor and the rotating shaft are directly connected, but in the case of an electric motor, the number of revolutions is several thousand revolutions per minute, so the speed is increased by a speed increaser for driving.

FIG. 3 shows a turbo compressor driven by an electric motor. In the electric motor 1, a rotor 4 is integrated with a rotor shaft 7 and is rotatably supported by a bearing 7, and a stator 6 is arranged around the rotor 4. The rotor 4 and the stator 6 are covered with a casing 8, a fan 9 is fixed to the rotor shaft 5 inside, and the rotor 4 and the stator 6 are cooled by the rotation of the rotor shaft 5. The rotor shaft 5 is connected to the speed increasing gear 3, and the compressor 2 is directly connected to the output shaft of the speed increasing gear 3. The speed increaser 3 increases the speed by a factor of ten and several times, and the compressor 2 is driven at tens of thousands of revolutions per minute.

[0004]

In recent years, advances in power electronics such as power transistors and thyristors have made possible high-speed motors, some of which have tens of thousands of revolutions per minute. Such a high-speed electric motor can be directly connected to the compressor without going through the gearbox. When the fan shown in FIG. 3 is used for cooling because a lot of heat is generated from the rotor due to high speed rotation, it is necessary to lengthen the rotor shaft by the amount of the fan attached. Such a long length may cause vibration. If the cooling of the fan is insufficient, the rotor may be deformed by heat and may not operate at high speed.

The present invention has been made in view of the above problems, and an object of the present invention is to reliably cool a high-speed electric motor without generating vibrations or the like.

[0006]

To achieve the above object, in the invention of claim 1, an electric motor, a compressor directly connected to a rotor shaft of the electric motor, and cooling for cooling compressed air compressed by the compressor. And a cooling line for introducing a part of the compressed air cooled by the cooler into the casing of the electric motor.

Since the compressor is often equipped with a cooler for cooling the temperature of the compressed air, a part of the compressed air cooled by the cooler is introduced into the casing of the electric motor, so that the rotor and the stator are cooled. Cool down. This eliminates the need for a fan, shortens the rotor shaft, and prevents vibrations. Further, the inside of the motor casing can be surely cooled by using the air cooled by the cooler.

According to the second aspect of the present invention, an electric motor, a first compressor directly connected to one end of a rotor shaft of the electric motor, and a compression directly connected to the other end of the rotor shaft and compressed by the first compressor. A second compressor for compressing air, an aftercooler for cooling the compressed air compressed by the second compressor, and a cooling line for introducing a part of the compressed air cooled by the aftercooler into the casing of the electric motor. Prepare

A first compressor is directly connected to one end of an electric motor rotor shaft, and a second compressor is directly connected to the other end of the motor rotor shaft. A part of this cooled compressed air is introduced into the casing of the electric motor to cool the rotor and the stator. This eliminates the need for a fan, shortens the rotor shaft, and prevents vibrations.
Further, the inside of the motor casing can be surely cooled by using the air cooled by the aftercooler.

According to a third aspect of the present invention, an electric motor, a first compressor directly connected to one end of a rotor shaft of the electric motor, an intercooler for cooling compressed air compressed by the first compressor, and the rotor shaft. A second compressor that is directly connected to the other end of the compressor and that compresses the compressed air cooled by the intercooler; and a cooling line that introduces part of the compressed air cooled by the intercooler into the casing of the electric motor.

The first compressor is directly connected to one end of the motor rotor shaft, the second compressor is directly connected to the other end, and the compressed air compressed by the first compressor is cooled by the intercooler to cool the second compressor. Supply to. A part of this cooled compressed air is introduced into the casing of the electric motor to cool the rotor and the stator. This eliminates the need for a fan, shortens the rotor shaft, and prevents vibrations. Further, the inside of the motor casing can be reliably cooled by using the air cooled by the intercooler.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a configuration of a turbo type air compressor of the present embodiment. The rotor 4 of the electric motor 1 is fixed to a rotor shaft 5, and the rotor shaft 5 is supported by a bearing 7 so as to be rotatable at high speed. A stator 6 is arranged around the rotor 4 and rotates the rotor 4 by an electromagnetic force. The rotor 4 and the stator 6 are covered with a casing 8. The electric motor 1 is manufactured using power electronics and rotates at high speed, for example, tens of thousands of revolutions per minute.

Both ends of the rotor shaft 5 project from the casing 8, a first compressor 21 is connected to one end, and a second compressor 22 is connected to the other end. First compressor 21
The impeller 21a is connected to the rotor shaft 5, and the impeller 21a is covered with the compressor casing 21b. Similarly, the second
The impeller 22a of the compressor 22 is coupled to the rotor shaft 5, and the impeller 22a is covered with a compressor casing 22b.

The compressor casing 21b of the first compressor 21.
Of the second compressor 22 and the inlet of the compressor casing 22b of the second compressor 22 are connected by a connection path 11, and an intercooler 12 is provided in the connection path 11 to cool the compressed air compressed by the first stage compressor 21. . An aftercooler 13 is provided at the outlet of the compressor casing 22b of the second compressor 22 to cool the compressed air compressed by the second compressor 22.

The intercooler 12 and the aftercooler 13 are provided with a cooling pipe 12a and a cooling pipe 13a, respectively, and are cooled by cooling water or air. A cooling line 14 is provided to connect the outlet side of the aftercooler 13 and the inlet 8a of the casing 8 of the electric motor 1 to supply cooling air. Cooling line 1
4 is provided with an orifice 14a, and the compressed air is depressurized to almost atmospheric pressure and supplied into the casing 8.

An inlet 8a and an outlet 8b are provided on the left and right sides of the casing 8 with the rotor 4 sandwiched between them. The cooling air flowing from the inlet 8a flows around the rotor 4 and the stator 5, and the outlet 8
It is discharged from b. As a result, the inside of the casing 8 is sufficiently cooled.

FIG. 2 is a diagram showing the configuration of the second embodiment. This embodiment is the same as the first embodiment except that the cooling line 14 is arranged from the outlet of the aftercooler 13 to the inlet 8a of the casing 8. The performance is also equivalent to that of the first embodiment.

[0018]

As is apparent from the above description, according to the present invention, the compressed air of the compressor driven by the electric motor is cooled by the cooler and a part thereof is introduced into the electric motor casing. It is possible to sufficiently cool the heat generating part of. Aftercoolers and intercoolers are used as coolers, and cooling air is extracted from their outlets and introduced into the casing. As a result, it is not necessary to provide a fan as in the conventional case, the rotor shaft is shortened accordingly, and shaft vibration is less likely to occur.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 3 is a diagram showing an example in which an output of an electric motor is increased by a speed increaser to drive a compressor.

[Explanation of symbols]

 1 Electric Motor 4 Rotor 5 Rotor Shaft 6 Stator 7 Bearing 8 Casing 8a Inlet 8b Outlet 11 Communication Path 12 Intercooler 12a, 13a Cooling Pipe 13 Aftercooler 14 Cooling Line 14a Orifice 21 First Compressor 22 Second Compressor 21a, 22a Impeller 21b , 22b Compressor casing

Claims (3)

[Claims] 1. An electric motor, a compressor directly connected to a rotor shaft of the electric motor, a cooler for cooling the compressed air compressed by the compressor, and a part of the compressed air cooled by the cooler for the electric motor. A turbo-type air compressor comprising: a cooling line introduced into the casing. 2. An electric motor, a first compressor directly connected to one end of a rotor shaft of the electric motor, and a first compressor directly connected to the other end of the rotor shaft to compress compressed air compressed by the first compressor. Two compressors, an aftercooler for cooling the compressed air compressed by the second compressor, and a cooling line for introducing a part of the compressed air cooled by the aftercooler into the casing of the electric motor. A turbo type air compressor. 3. An electric motor, a first compressor directly connected to one end of a rotor shaft of the electric motor, an intercooler for cooling compressed air compressed by the first compressor, and an other end of the rotor shaft. A turbo including a second compressor that is directly connected to compress the compressed air cooled by the intercooler, and a cooling line that introduces a part of the compressed air cooled by the intercooler into the casing of the electric motor. Type air compressor.