JPH0666285A - Compressor - Google Patents

Abstract

PURPOSE:To cool an electric motor sufficiently using low-temperature lubricating oil by using cooling means to cool lubricating oil which is discharged from a compressor together with gas, returning the lubricating oil into the oil reservoir of a compressor, sucking the lubricating oil using an oil pump, and introducing the oil into the electric motor through a non-oil passage. CONSTITUTION:Gas of helium and the like which is compressed by a compressor 101 is discharged with lubricating oil contained therein and allowed to enter an oil separator, where the gas is separated from the lubricating oil. The lubricating oil separated from the gas by the oil separator is allowed to pass through a return pipe and enter an oil cooler and is cooled there by cooling water and then returned into a compressor 101 via a suction pipe 82 and retained in the oil reservoir 81 of the compressor. Lubricating oil in the oil reservoir 81 is therefore held at low temperatures. The lubricating oil in the oil reservoir 81 is sucked by an oil pump 51 and supplied to sliding parts such as an upper bearing 71 and a turning bearing 73 through an oil hole 52 and lubricates them. Therefore, an electric motor can be cooled sufficiently by the low-temperature lubricating oil.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetic compressor used in a gas compression unit for helium gas or the like.

[0002]

2. Description of the Related Art An example of a conventional scroll type compressor is shown in FIG.

Inside the closed housing 8, a scroll type compression mechanism C is installed in the upper part thereof, and an electric motor M consisting of a rotor Ma and a stator Mb is installed in the lower part thereof, which are interlockingly connected to each other via a rotary shaft 5. There is.

The scroll-type compression mechanism C allows the fixed scroll 1, the orbiting scroll 2 and the orbiting scroll 2 to freely rotate, but allows the orbiting scroll 2 and the rotation inhibiting mechanism 3 such as an Oldham link to prevent its rotation. It comprises a frame 6 for supporting, a bearing 71 for supporting the rotating shaft 5 and the like.

A centrifugal oil pump 51 is incorporated in the lower portion of the rotary shaft 5, and the lubricating oil stored in an oil sump 81 at the bottom of the closed housing 8 is passed through an oil supply hole 52 bored in the rotary shaft 5. It is supposed to be supplied.

By driving the electric motor M, the orbiting scroll 2 is driven via the rotary shaft 5 and the like, and the orbiting scroll 2 revolves around the axis while being prevented from rotating by the rotation preventing mechanism 3.

Then, the gas enters the closed housing 8 through the suction pipe 82, and in the process of passing through the closed housing 8, the electric motor M
While being cooled, it is sucked into the compression chamber 24 formed by the fixed scroll 1 and the orbiting scroll 2. And
The orbiting scroll 2 revolves around the discharge port 13 while being compressed as the volume of the compression chamber 24 decreases.
Enters the discharge cavity 14 and is discharged to the outside through the discharge pipe 83.

At the same time, the lubricating oil in the oil sump 81 is sucked up by the oil pump 51 and supplied to the sliding parts such as the upper bearing 71 and the swivel bearing 73 through the oil supply hole 52.
Lubricate these. The surplus lubricating oil is discharged to the oil sump 81 through the oil discharge passage 62 formed in the frame 6.

[0009]

The conventional scroll type compressor described above has the following problems to be solved.

That is, in the conventional compressor described above, the electric motor M is cooled by the gas sucked into the closed housing 8 through the suction pipe 82.

However, when the compressor is used in a gas compression unit for helium gas or the like, it is difficult to sufficiently cool it with helium gas having a small cooling capacity, and the temperature of the electric motor M rises to cause a burnout accident. May invite.

In view of the above circumstances, it is an object of the present invention to provide a compressor having means for sufficiently cooling an electric motor.

[0013]

As a means for solving the above problems, the present invention accommodates a compression mechanism for compressing gas and an electric motor for driving the compression mechanism via a rotary shaft in a hermetically sealed housing, The oil pump incorporated in the suction housing sucks up the lubricating oil stored in the oil reservoir at the bottom of the closed housing to supply the sliding parts such as the compression mechanism with excess lubricating oil from the drain passage to the oil reservoir. In the hermetic compressor discharged, cooling means for cooling the lubricating oil discharged along with the gas from the compression mechanism,
A compressor provided with a lubricating oil return pipe communicating the cooling means with the oil sump, and an outlet for guiding the lubricating oil discharged from the drain oil passage to the electric motor. It is what

[0014]

Since the present invention is constructed as described above, it has the following actions.

That is, a cooling means for cooling the lubricating oil discharged from the compression mechanism along with the gas is provided, and a lubricating oil return pipe communicating the cooling means with the oil sump is provided. Since the lubricating oil discharged from the compressor to the electric motor is provided with an outlet for guiding the lubricating oil to the electric motor, the lubricating oil discharged along with the gas from the compressor is cooled by the cooling means and then returned to the oil reservoir through the return pipe. Therefore, the temperature of the lubricating oil in the oil sump is maintained at a low temperature.

The low temperature lubricating oil in the oil sump is sucked up by an oil pump, a part of it is supplied to the sliding portion of the compression mechanism, and the surplus lubricating oil is poured into the electric motor from the drain oil passage through the outlet. Peel off and cool it.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a vertical cross-sectional view of a scroll-type compressor 101 of the present embodiment. The same members as those of the conventional compressor shown in FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted unless necessary. .

In FIG. 1, the outlet 62a of the oil drain passage 62 formed in the frame 6 is located directly above the stator Mb of the electric motor M. It is also possible to provide two or more outlets 62a and position them directly above the stator Mb, or connect a pipe to the outlet 62a and extend the other end near the stator Mb. The other configuration inside the compressor 101 is the same as the conventional example.

FIG. 2 is a system diagram of a gas compression unit incorporating the compressor 101 of FIG. 1. An oil separator 102, a discharge gas cooler 103 and an adsorber 104 are connected to the discharge side of the compressor 101, and the compressor 101. The surge bottle 105 is connected to the suction side of the.

The lower part of the oil separator 102 is the return pipe 1
An oil cooler 107 is interposed in the return pipe 106 by communicating with the suction pipe 82 of the compressor 101 by 06.

Next, the operation of the above configuration will be described. The gas such as helium compressed by the compressor 101 is discharged in a state containing lubricating oil and enters the oil separator 102,
Here, the gas and the lubricating oil are separated. The gas separated from the lubricating oil is guided to the discharge gas cooler 103, where it is cooled by cooling water. Then the gas is adsorber 104
After the oil vapor contained in the gas is removed, it is sent to the expansion mechanism of a cryogenic refrigerator (not shown). The gas flowing from the cryogenic refrigerator passes through the surge bottle 105 and is sucked into the compressor 101 through the suction pipe 82.

The lubricating oil separated from the gas by the oil separator 102 passes through the return pipe 106 and enters the oil cooler 107, where it is cooled by the cooling water and then the suction pipe 82.
It returns to the compressor 101 and is stored in the oil sump 81.

Therefore, the lubricating oil in the oil sump 81 is kept in a low temperature state.

On the other hand, the lubricating oil in the oil sump 81 is the oil pump 5
1, the upper bearing 7 passes through the oil supply hole 52,
1. Lubricated by being supplied to sliding parts such as the orbiting bearing 73. Excess lubricating oil is drained from the oil drain passage 6 formed in the frame 6.
After being discharged from the outlet 62a through the nozzle 2 and being poured into the stator Mb, it falls into the oil sump 81.

Thus, by pouring the lubricating oil of low temperature and large heat capacity directly onto the stator Mb,
Of the stator Mb,
As a result, the temperature rise of the electric motor M can be prevented.

As described above, according to this embodiment, the lubricating oil cooled by the oil cooler 107 is returned to the compressor 10 by the return pipe 106.
1 is returned to the oil sump 81, which is sucked up by the oil pump 51 to lubricate a required part, and the remaining part is drained by the oil discharge passage 62 and the outlet 6.
Since it is poured into the electric motor M via 2a, the electric motor M is cooled by the low temperature lubricating oil, and there is an advantage that there is no fear of causing a burnout accident as in the conventional case.

[0027]

Since the present invention is constructed as described above, it has the following effects.

That is, according to the present invention, the lubricating oil discharged together with the gas from the compressor is cooled by the cooling means and returned to the oil sump of the compressor, and this lubricating oil is sucked up by the oil pump and discharged from the exhaust oil passage. Since the electric motor is guided to the electric motor, the electric motor can be sufficiently cooled by the low temperature lubricating oil. As a result, it is possible to avoid a burnout accident caused by the temperature rise of the electric motor.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a compressor according to an embodiment of the present invention,

FIG. 2 is a system diagram of a gas compression unit using the above embodiment,

FIG. 3 is a vertical sectional view of a conventional compressor.

[Explanation of symbols]

 5 rotating shaft 8 hermetic housing 51 oil pump 62 drain oil passage 62a outlet 71 bearing 73 swivel bearing 82 suction pipe 83 discharge pipe 101 compressor 106 return pipe 107 oil cooler C compression mechanism M electric motor Ma rotor Mb stator

Claims (1)

[Claims] 1. A hermetically sealed housing containing a compression mechanism for compressing gas and an electric motor for driving the compression mechanism via a rotary shaft, and an oil pump incorporated in the rotary shaft to provide oil at the bottom of the hermetically sealed housing. In a hermetic compressor that sucks up the lubricating oil stored in the sump and supplies it to the sliding portion of the compression mechanism or the like and discharges the surplus lubricating oil from the oil discharge passage to the oil sump, Cooling means for cooling the lubricating oil discharged along with the gas, a lubricating oil return pipe communicating the cooling means with the oil reservoir, and guiding the lubricating oil discharged from the drain oil passage to the electric motor. A compressor comprising an outlet.