JPS5836865Y2 - Oil-injected electric compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an oil-injected electric compressor that cools an electric motor using water, oil, or a refrigerant.

For conventional screw compressors driven by standard air-cooled electric motors, when the compressor and electric motor are housed in a package for soundproofing, a suction muffling duct and an exhaust duct are installed at the intake button and outlet of the cooling air of the electric motor, respectively. is necessary,
It is also necessary to partition the intake and exhaust rooms.

One of the sources of noise in screw compressors is the rotating sound of the air cooling fan of the electric motor.

In particular, when a two-pole electric motor is adopted for miniaturization, the level of noise becomes even worse.

In order to eliminate these drawbacks, the present invention doubles the casing of the motor as a noise countermeasure, and between the casings water, oil, or refrigerant that is corrosive to the motor (mainly The motor is cooled by circulating a refrigerant (corrosive to copper and copper alloys).

Next, embodiments of the present invention will be described with reference to the drawings.

Figures 1a and 1b are flow diagrams when the motor is cooled with cooling water passed through the oil cooler in a cooling system equipped with an oil-injected electric compressor, where 1 is the compressor and 2 is the Compressor suction port, 3 is compressor discharge port, 4 is oil separator, 5 is oil outlet, 6 is oil quencher, I is coolant pipe, 8 is electric motor, 9 is coolant inlet, 10 is the coolant outlet.

In step a, oil is separated from the high-pressure refrigerant gas discharged from the discharge port 3 of the compressor 1 in the oil separator 4, and the separated oil is introduced into the oil cooler 6 through the oil outlet D5, where The cooling water in the oil cooler 6 is introduced into the oil cooler 6 from the pipe T, cools the oil there, and then enters the coolant port 9 of the electric motor 8 to cool the electric motor 8. It is cooled and discharged from the coolant discharge port 10, b
In K, cooling water is first introduced from the cooling water port 9 of the electric motor 8, and after cooling the electric motor 8, it is discharged from the coolant discharge port 10, and passes through the discharge pipe 11 to the oil cooler 6.
The structure is such that it is cooled before being discharged.

Figure 2 is a flow system diagram when an electric motor is cooled with oil cooled by an oil cooler in a cooling system equipped with an oil-injected electric compressor. Omitted.

6' is an air-cooled oil cooler, 8 is an electric motor, 9 is a coolant inlet,
10 is a coolant discharge port, and 12 is a discharge pipe.

The oil cooled by the air-cooled oil cooler 6' is introduced from the coolant port 9 of the electric motor 8, cools the electric motor 8, is discharged from the coolant outlet 10, and is supplied to the compressor 1 from the discharge pipe 12. It is something that

Figure 3 shows the flow system when a cooling system equipped with an oil-injected electric compressor is used to cool the motor with a refrigerant that is corrosive to the motor (mainly a refrigerant that is corrosive to copper and copper alloys). In the figure, 1 is a compressor, 2 is a suction port of the compressor, 3 is a discharge port of the compressor, 4 is an oil separator, 13 is a condenser, 14 is an expansion valve, 15 is an evaporator, 16 is a refrigerant pipe, 8 is an electric motor, 9 is a coolant inlet of the electric motor, and 10 is a coolant outlet.

The high-pressure refrigerant gas discharged from the discharge port 3 of the compressor 1 is separated from oil by the oil separator 4, introduced into the condenser 13 to become refrigerant liquid, expanded by the expansion valve 14, and converted into low-pressure refrigerant gas by the evaporator 15. Next, the coolant population 9 of the electric motor passes through the coolant pipe 16
coolant outlet 1 after cooling the motor there.
0 and introduced into the compressor 8 through the suction port 2 of the compressor 8.

FIG. 4a is a partially cutaway vertical cross-sectional view of the electric motor with a double casing structure according to the present invention, and FIG. 4 is a cross-sectional view taken along line A-A in FIG. , 8 is an electric motor, 11 is a double casing, 18 is a stator, 19 is a rotor, 20
9 is a shaft, 9 is a coolant inlet, 10 is a coolant outlet, and 21 is a coolant flow path.

The coolant used in the compressor, such as water, oil, and corrosive refrigerant, is introduced from the population 9 and flows along the coolant flow path 21 formed between the double casing 17 of the electric motor 8. After the electric motor 8 is cooled down, the coolant is discharged from the coolant discharge 10.

As mentioned above, this invention uses two electric motors for an oil-injected electric compressor.
The heavy casing is configured to cool the motor by circulating water, oil, or a refrigerant used in the compressor between the casings, resulting in the following effects. .

(1) An electric compressor that uses a conventional standard air-cooled electric motor and is fitted with a button soundproof package requires a suction muffling duct and an exhaust duct at the air intake and exhaust section for cooling the motor. Although it was necessary to partition the exhaust section room with a partition plate, the present invention eliminates the need for a suction muffling duct, an exhaust duct, and a partition plate, making it possible to reduce the manufacturing cost of the sound muffling package.

(2) It is possible to downsize the oil-injected electric compressor.

(3) Noise is reduced because an electric motor air cooling fan is not required.

(4) In order to downsize the screw compressor and omit parts, the electric motor rotor shaft and the compressor screw rotor shaft or the gear 1 drive shaft are integrated and directly driven by providing a connection box via a flexible coupling. Although a better structure would be better, a structure in which the motor rotor overhangs is suitable for this purpose.

In this case, a standard air-cooled motor has a cooling fan, so
This increases the distance between the rotor center of gravity and the bearing that supports the rotor, which is disadvantageous in terms of structure.

In the present invention, since there is no cooling fan for the electric motor, it is easy to create a structure in which the rotor is overhanged.

[Brief explanation of drawings]

Figures 1a and 1b are flow diagrams when an electric motor is cooled by cooling water introduced into or discharged from an oil cooler according to the present invention;
Figure 2 is a flow system diagram when an electric motor is cooled with oil cooled by the oil cooler according to the present invention, Figure 3 is a flow system diagram when an electric motor is cooled with a refrigerant according to the present invention, and Figure 4 a.
, is a vertical cross-sectional view of a double casing electric motor according to the present invention. FIG. 4 is a sectional view taken along the line A--A in FIG. 4a. 1 is a compressor, 6 and 6' are oil coolers, 8 is an electric motor, and 17 is a double casing.

Claims (1)

[Scope of utility model registration request] A refrigerating machine that has a double-layered motor casing for an oil-injected electric compressor and is used in combination with the compressor.
An oil-injected electric compressor characterized in that the electric motor is cooled by supplying a cold source contained in a device such as an air conditioner or the like between a casing of the electric motor.