JPH05256259A - Reciprocating compressor - Google Patents

Abstract

PURPOSE:To suppress overheat of suction gas and also to improve an effect of reducing a noise by providing communication holes in a suction pipe, by which a suction passage of a compression element part is connected to a suction pipe of a closed case, and a sleeve of communicating with space in the case by covering these communication holes. CONSTITUTION:A refrigerant intermittently flows into a suction pipe 16 through a suction pipe 15 by reciprocating motion of a piston 5. When a cylinder 8 is placed in a suction stroke, suction gas, left as it is, flows into the cylinder 8, but when it is transferred to a compression stroke by ending the suction stroke, the suction gas, because of its inertia force, continues to flow in the suction pipe 16 for a short time. Here are provider communication holes 16a, 16b, 16c in the suction pipe 16, and the suction gas partly flows out into a closed case 2 from these communication holes. Each communication hole, whose opening hole position, quantity and hole size are matched with a noise frequency, effectively reduces a noise. A sleeve 17 having fine space holes 18 is provided by covering this opening hole, to further reduce the noise by suppressing a pulsation of gas.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suction pipe in a closed case of a reciprocating compressor used in a refrigerating machine or the like.

[0002]

2. Description of the Related Art Conventionally, in a reciprocating compressor, it is more efficient to suck the refrigerant gas flowing into the compressor from the cooling system into the compression element without overheating. The suction pipe of the closed case and the suction passage of the compression element were communicated with each other. As this conventional technique, for example, there is an intake muffler disclosed in Japanese Examined Patent Publication No. 64-1498.

An example of the above-mentioned conventional suction muffler will be described below with reference to the drawings.

FIG. 5 is a sectional view of a conventional reciprocating compressor, and FIG. 6 is a top view. In the figure, 1 is a reciprocating compressor and 2 is a closed case. 3 is an electric motor, which is composed of a stator 3a and a rotor 3b. Reference numeral 4 is a compression element, which is composed of a piston 5, a connecting rod 6, a shaft 7, a cylinder 8 and the like. The compression element 4 is fixed to the stator 3a with a screw to form an electric compression element 9.

Reference numerals 10a, 10b, 10c and 10d denote springs, which elastically support the electric compression element 9 in the closed case 2. A discharge pipe 11 elastically connects the compression element 4 to the outlet pipe 12 fixed to the closed case 2.
Reference numeral 13 denotes an expansion-type or interference-type suction muffler having a space therein, and is connected to the suction passage 4a of the compression element 4 and the suction pipe 15 by suction pipes 14a and 14b and a suction spring 14c. The suction pipe 14 is partially inserted into the suction muffler 13, and the suction muffler is made of a material having low thermal conductivity such as plastic.

The operation of the reciprocating compressor having the above structure will be described below. Rotor 3 of electric motor 3
With the reciprocating motion of the connecting rod 6 and the piston 5 due to the rotation of a, the suction pipe 15, the suction pipes 14a, 14b, the suction spring 14c, the suction muffler 13, and the suction passage 4a are connected from a system pipe (not shown) such as a refrigerating machine. Refrigerant gas is sucked into the compression element 4 via the compression element 4. At this time, a part of the sucked refrigerant gas flows into the closed case 2 through a slight gap of the suction spring 14c to keep the closed case 2 at a low pressure.

Therefore, the action of the suction muffler 13 can suppress the generation of noise due to the pulsation of the suction gas,
Also, because the suction muffler is made of plastic,
It is possible to suppress overheating of the intake gas. Further, the refrigerant gas compressed by the reciprocating motion of the piston 5 is discharged by the discharge pipe 1.
1, discharged through the outlet pipe 12 into the system pipe.

[0008]

However, in the above-mentioned structure, the volume of the suction muffler needs to be sufficiently large in order to sufficiently bring out the noise reduction effect due to the pulsating flow of the suction gas. However, even if it is made of plastic, there is a problem that the overheating when the suction gas is sucked into the muffler is still considerably large due to the heat conduction from the compression element.

The present invention solves the conventional problems, and an object thereof is to minimize the overheating of the intake gas and to maximize the noise reduction effect.

[0010]

In order to achieve this object, a reciprocating compressor according to the present invention comprises a hermetically sealed case, an electric compression element section housed in the hermetically sealed case, the electric compression element section being composed of a compression element section and an electric motor section. A suction pipe having a communication hole that connects the suction passage of the compression element portion and the suction pipe of the closed case and communicates the inner and outer surfaces, and a space inside the closed case that covers the communication hole of the suction pipe and has a plurality of holes. And a sleeve that communicates with each other.

Further, the hermetically sealed case, the electric compression element section which is housed in the hermetically sealed case and which is composed of the compression element section and the electric motor section, the suction passage of the compression element section and the suction pipe of the hermetically sealed case are connected through a discontinuous portion. It is composed of a suction pipe that is substantially connected and a sleeve that covers the discontinuous portion of the suction pipe and that communicates the space in the closed case with the discontinuous portion by a plurality of holes.

Further, a sleeve which covers the discontinuous portion of the suction pipe and communicates the space inside the closed case with the discontinuous portion by a plurality of holes, and a sleeve which is provided on a part of the inner diameter side of the sleeve and has a larger inner diameter cross-sectional area than the suction pipe. And a space chamber having a cross-sectional area.

The sleeve is formed of a foam metal having a lower thermal conductivity than copper, a porous metal such as a porous sintered body, or a porous organic material such as foam plastic.

[0014]

With the reciprocating compressor of the present invention having the above-mentioned structure, the noise associated with the pulsation of the suction gas is stored in the gas sealing case in the communication hole, the discontinuity, and the hole of the sleeve provided in the suction pipe. It is suppressed by the minimum inflow and outflow of and, and since the inner volume of the sleeve is smaller than that of the conventional suction muffler, overheating of the suction gas can be prevented and efficiency is improved. Further, by forming the sleeve from foam metal or foam plastic having a lower thermal conductivity than copper, the overheating of the intake gas is further reduced and the efficiency is improved.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a reciprocating compressor according to the present invention will be described below with reference to the drawings. It should be noted that the same components as those of the related art will be denoted by the same reference numerals and detailed description thereof will be omitted.

FIG. 1 is a top view showing a compression element portion of a reciprocating compressor according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of the suction part of the same embodiment.

In FIGS. 1 and 2, reference numeral 16 is a suction pipe, and communication holes 16a, 16 for communicating the inner and outer surfaces of the pipe.
b, 16c. Reference numeral 17 denotes a sleeve, which has many fine holes 18. The hole 18 is the sleeve 17
The inner and outer surfaces of are securely connected.

The operation of the reciprocating compressor having the above structure will be described below. Due to the reciprocating motion of the piston 5, the refrigerant intermittently flows into a suction pipe 16 from a system pipe (not shown) such as a refrigerating machine via a suction pipe 15. At this time, when the inside of the cylinder 8 is in the intake stroke, the intake gas flows into the cylinder 8 through the intake passage 4a as it is. However, when the intake stroke is completed and the compression stroke is started, the intake gas has an inertial force. Immediately, the inflow does not stop and continues to flow into the suction pipe 16.

As a result, the communication hole 16a of the suction pipe 16 is
A part of the liquid flows out of the sealed case from 16b and 16c. Since the communication holes 16a, 16b, 16c can be opened in accordance with the frequency of noise to be reduced in the position of the hole, the number of holes, and the diameter of the hole, the frequency to be effectively reduced can be reduced. Also,
Due to the effect of the sleeve having the holes 18, the communication holes 16
It is possible to widen the band of the noise reduction frequency in a, 16b, 16c, and further reduce the pulsation while minimizing the amount of the refrigerant gas flowing from the communication holes 16a, 16b, 16c into the closed case. Also, the overheating of the refrigerant gas can be minimized, noise can be reduced, and efficiency can be improved.

As described above, the reciprocating compressor of this embodiment is
The suction passage 4a of the compression element portion 4 and the suction pipe 1 of the closed case 2
Communication holes 16a, 16 for connecting 5 and communicating the inner and outer surfaces
suction pipe 16 having b and 16c, and suction pipe 16
Of the communication holes 16a, 16b, 16c of the casing 1 and a plurality of holes 18 and the communication holes 16a, 16
Since it is composed of a sleeve that communicates b and 16c, the communication holes 16a, 16b, and 16c can be opened in accordance with the frequency of noise to be reduced in the opening position, the number of openings, and the opening diameter. The frequency to be reduced can be reduced.
Further, due to the effect of the sleeve having the holes 18, the noise reduction frequency band in the communication holes 16a, 16b, 16c can be widened, and further, the communication holes 16a, 16b, 16c.
The pulsation can be reduced while minimizing the amount of the refrigerant gas flowing out of the closed case to the sealed case, the overheating of the refrigerant gas can be minimized, the noise can be reduced, and the efficiency is improved.

Next, a second embodiment of the reciprocating compressor of the present invention will be described with reference to the drawings.

FIG. 3 is a sectional view of the suction part of the reciprocating compressor according to the second embodiment of the present invention. In FIG. 3, 19
Reference numerals a and 19b are suction pipes and have a discontinuous portion 19c. Reference numeral 20 denotes a sleeve, which has many fine holes 21. The hole 21 surely communicates the inner and outer surfaces of the sleeve 20.

The operation of the reciprocating compressor configured as described above will be described below. Due to the reciprocating motion of the piston 5, the refrigerant intermittently flows into the suction pipe 19a from a system pipe (not shown) such as a refrigerating machine via the suction pipe 15. At this time, when the inside of the cylinder 8 is in the intake stroke, the intake gas flows into the cylinder 8 through the discontinuous portion 19c, the intake pipe 19b, and the intake passage 4a as it is, but when the intake stroke ends and the compression stroke starts. Due to the inertial force, the suction gas does not stop flowing and immediately continues to flow into the suction pipe 19a.

As a result, a portion of the discontinuous portion 19c flows out into the sealed case. At this time, due to the effect of the sleeve 20 having the holes 18, the pulsation can be reduced, the band of the noise reduction frequency in the discontinuous portion 19c can be widened, and the noise can flow out from the discontinuous portion 19c to the closed case 2. In order to minimize the amount of refrigerant gas, overheating of the refrigerant gas can be minimized, noise can be reduced, and efficiency can be improved.

As described above, the reciprocating compressor of this embodiment is
The suction passage 4a of the compression element portion 4 and the suction pipe 1 of the closed case 2
5 for substantially connecting 5 through a discontinuous portion 19c
a, 19b and the discontinuous portion 19c of the suction pipe by covering the discontinuous portion 19c of the suction pipe with a plurality of holes 21.
and a sleeve 20 communicating with c,
Due to the effect of the sleeve 20 having the holes 18, the pulsation can be reduced, the band of the noise reduction frequency in the discontinuous portion 19c can be widened, and the refrigerant gas flowing out from the discontinuous portion 19c to the closed case 2 can be prevented. In order to minimize the amount, overheating of the refrigerant gas can also be minimized, noise can be reduced,
Efficiency is improved.

Next, a third embodiment of the reciprocating compressor of the present invention will be described with reference to the drawings. The same components as those in the second embodiment are designated by the same reference numerals and detailed description thereof will be omitted.

FIG. 4 is a sectional view of a suction part of a reciprocating compressor according to a third embodiment of the present invention. In FIG. 4, reference numeral 22 denotes a sleeve, which has many fine holes 23.
The hole 23 surely communicates the inner and outer surfaces of the sleeve 22. Further, the suction pipe 19 is provided on the inner diameter side of the sleeve 22.
It has a space chamber 22a having a cross-sectional area larger than the inner diameter cross-sectional areas of a and 19b.

The reciprocating compressor configured as described above is
In addition to the second embodiment, the effect of the partial expansion type muffler is added by the space chamber 22a, and the noise can be further reduced.

As described above, the reciprocating compressor of this embodiment is
The sleeve 22 that covers the discontinuous portion 19c of the suction pipe and communicates the space inside the closed case 2 with the discontinuous portion 19c by the plurality of holes 23, and the inner diameters of the suction pipes 19a and 19b that are provided on a part of the inner diameter side of the sleeve 22. The space chamber 22a has a cross-sectional area larger than the cross-sectional area, and in addition to the effect of the second embodiment, the space chamber 22a adds the effect of a partial expansion type muffler, and noise can be further reduced.

Next, a fourth embodiment of the reciprocating compressor of the present invention will be described with reference to the drawings. The first,
The same components as those in the second and third embodiments are designated by the same reference numerals and detailed description thereof will be omitted.

In this embodiment, in the first, second, and third embodiments, the sleeves 17, 20, and 22 are made of a metal foam having a thermal conductivity smaller than that of copper, or a porous sintered body such as a porous sintered body. It is formed of a porous metal such as a porous metal or a foamed plastic.

The reciprocating compressor configured as described above is
In addition to the effects of the first, second, and third embodiments, the sleeve itself is made of a material having a high heat insulating property, and the heat transfer from the refrigerant gas in the closed case 2 and the suction pipes 16, 19a, 19b. Can be suppressed and efficiency can be further improved.

As described above, the reciprocating compressor of this embodiment is
The material of the sleeves 17, 20, 22 is formed of a foam metal, a porous metal, or a porous organic material having a thermal conductivity smaller than that of copper, and has the effect of the first, second, and third embodiments. In addition, the refrigerant gas in the closed case 2 and the suction pipes 16, 1
The heat conduction from 9a and 19b can be suppressed, and the efficiency can be further improved.

In this embodiment, instead of the conventional muffler, the communication hole or discontinuity of the suction pipe and the sleeve are used to improve the efficiency and reduce the noise. It goes without saying that if a muffler is provided as in the conventional case, it is possible to further improve efficiency and reduce noise.

[0035]

As described above, according to the present invention, the suction pipe having the communication hole for connecting the suction passage of the compression element portion and the suction pipe of the closed case and for communicating the inner and outer surfaces, and the communication hole of the suction pipe are covered. In addition, since it is composed of a sleeve that connects the space in the closed case with the communication hole by a plurality of holes, the communication hole has the position, the number of holes, and the diameter of the communication hole according to the frequency of noise to be reduced. Since the holes can be opened, the frequency to be effectively reduced can be reduced. Further, due to the effect of the sleeve having the holes, the pulsation can be reduced, the band of the noise reduction frequency in the communication hole can be widened, and the amount of the refrigerant gas flowing out from the communication hole to the closed case can be minimized. Pulsations can be reduced while suppressing, overheating of the refrigerant gas can be minimized, noise can be reduced, and efficiency can be improved.

Further, according to the present invention, the suction case which substantially connects the suction passage of the compression element portion and the suction pipe of the closed case through the discontinuous portion, and the closed case which covers the discontinuous portion of the suction pipe and has a plurality of holes. It is composed of a sleeve that communicates the internal space with the discontinuous portion, and due to the effect of the sleeve having holes, it is possible to reduce pulsation and widen the noise reduction frequency band at the discontinuous portion. Further, since the amount of the refrigerant gas flowing from the discontinuous portion to the closed case is minimized, the overheating of the refrigerant gas can be minimized, the noise can be reduced, and the efficiency is improved.

Further, according to the present invention, a sleeve which covers the discontinuous portion of the suction pipe and communicates the space in the closed case with the discontinuous portion by a plurality of holes, and an inner diameter of the suction pipe which is provided at a part of the inner diameter side of the sleeve. The space chamber has a cross-sectional area larger than the cross-sectional area. In addition to the effect of the second embodiment, the space chamber partially adds the effect of the expansion type muffler, and noise can be further reduced.

Further, in the present invention, the material of the sleeve is formed of a foam metal, a porous metal or a porous organic material having a thermal conductivity smaller than that of copper. The first, second and third embodiments In addition, the heat transfer from the refrigerant gas in the closed case and the suction pipe can be suppressed, and the efficiency can be further improved.

[Brief description of drawings]

FIG. 1 is a top view showing a compression element portion of a reciprocating compressor showing an embodiment of the present invention.

FIG. 2 is a sectional view of a suction part of the reciprocating compressor of the same embodiment.

FIG. 3 is a sectional view of a suction part of a reciprocating compressor showing second and fifth embodiments according to the present invention.

FIG. 4 is a sectional view of a suction portion of a reciprocating compressor according to third and fifth embodiments of the present invention.

FIG. 5 is a vertical sectional view of a conventional reciprocating compressor.

FIG. 6 is a top view showing a compression element portion of a conventional reciprocating compressor.

[Explanation of symbols]

 2 closed case 3 electric motor 4 compression element 4a suction passage 9 electric compression element 16 suction pipe 16a, 16b, 16c communication hole 17 sleeve 18 hole 19a, 19b suction pipe 19c suction pipe discontinuity 20 sleeve 21 hole 22 sleeve 22a Space room 23 holes

Claims (6)

[Claims] 1. A hermetically sealed case, an electric compression element section housed in the hermetically sealed case and constituted by a compression element section and an electric motor section, a suction passage of the compression element section and a suction pipe of the hermetically sealed case, and inner and outer surfaces thereof are connected to each other. A reciprocating compressor comprising: a suction pipe having a communication hole communicating with each other; and a sleeve which covers the communication hole of the suction pipe and communicates the space in the closed case with the communication hole by a plurality of holes. 2. A hermetically sealed case, an electric compression element section housed in the hermetically sealed case and configured by a compression element section and an electric motor section, and a suction passage of the compression element section and a suction pipe of the hermetically sealed case via a discontinuous section. A reciprocating compressor including a suction pipe that is substantially connected to the suction pipe, and a sleeve that covers the discontinuous portion of the suction pipe and communicates the space in the closed case with the discontinuous portion by a plurality of holes. 3. A sleeve which covers the discontinuous portion of the suction pipe and communicates the space inside the closed case with the discontinuous portion by a plurality of holes, and a sleeve which is provided at a part of the inner diameter side of the sleeve and is larger than the inner diameter cross-sectional area of the suction pipe. The reciprocating compressor according to claim 2, comprising a space chamber having a cross-sectional area. 4. The reciprocating compressor according to claim 1, 2, or 3, wherein the sleeve is made of foam metal having a thermal conductivity lower than that of copper. 5. The reciprocating compressor according to claim 1, 2 or 3, wherein the sleeve is formed of a porous metal such as a porous sintered body having a thermal conductivity smaller than that of copper. 6. The reciprocating compressor according to claim 1, 2 or 3, wherein the sleeve is made of a porous organic material such as foamed plastic having a thermal conductivity smaller than that of copper.