JPH0610838A - Reciprocating compressor - Google Patents

Abstract

PURPOSE:To reduce a suction loss of a reciprocating compressor with no increase of noise and further to prevent overheating suction gas. CONSTITUTION:A compressor is constituted of a closed case 2, electric motor driven compression element 9 housed in the closed case 2 to be constituted of a compression element 4 and an electric motor 3, cylinder 8 of constituting the compression element 4, suction path 17 for connecting a suction pipe 15 of the closed case 2 to the cylinder 8 and a check valve mechanism 18 provided in the suction path.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suction passage 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 that the refrigerant gas flowing into the compressor from the cooling system is sucked into the compression element through the suction passage without overheating, and the refrigerant gas In order to suppress the generation of noise due to the pulsation, the suction pipe of the closed case and the suction passage of the compression element are connected via a suction muffler. As this conventional technique, for example, there is an intake muffler disclosed in Japanese Patent Publication No. 64-1498.

An example of the above-mentioned conventional suction passage will be described below with reference to the drawings. FIG. 5 is a vertical sectional view of a conventional reciprocating compressor, and FIG. 6 is a top view. FIG. 7 is a sectional view of the suction passage taken along the line BB of FIG. In FIGS. 5, 6 and 7, 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. A compression element 4 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 constitute 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 11b 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 inside, 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, respectively. Suction pipe 14
Is partially inserted into the suction muffler 13, and the suction muffler 13 is made of a material having low thermal conductivity such as plastic.

Reference numeral 16a denotes a suction hole which communicates between the suction passage 4a and the cylinder 8. 16b is a suction lead for opening and closing the suction hole 16a. Reference numeral 17 denotes an intake passage, which connects the intake pipe 15 to the cylinder 8, and includes an intake pipe 14, an intake muffler 13, and an intake passage 4a.
It consists of

The operation of the reciprocating compressor having the above structure will be described below. Rotor 3a of electric motor 3
Along with the reciprocating movement of the connecting rod 6 and the piston 5 due to the rotation of the suction pipe 15, suction pipes 15, suction pipes 14a, 14b, suction springs 14c, suction muffler 13, suction passage 4a, from a system piping (not shown) such as a refrigerating machine. Suction hole 4
Refrigerant gas is drawn into the cylinder 8 through the suction lead 4c. 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.

The refrigerant gas compressed by the reciprocating motion of the piston 5 is discharged by a discharge valve (not shown) and a discharge passage 11.
It is discharged to the system pipe through a, the discharge pipe 11, and the outlet pipe 12.

[0009]

However, in the structure as described above, in the intake stroke, the pressure in the cylinder and the pressure in the intake passage of the compression element are once reduced at the beginning of the intake stroke, but the volume in the cylinder is increased. When the inflow of the intake gas catches up with the pressure in the cylinder and the pressure in the intake passage of the compression element, the pressure in the intake passage is increased due to the flow resistance of the intake passage, the intake pipe and the intake muffler. Or higher than the pressure in the suction muffler.

Therefore, despite the intake stroke, the intake gas flows back from the intake passage to the intake pipe and the intake muffler. As a result, the intake gas cannot flow into the cylinder, increasing the intake loss and increasing the efficiency of the compressor. Had a problem that it decreased.

The present invention solves the conventional problems by preventing backflow of suction gas from the suction passage of the compression element into the suction pipe or the suction muffler, and always supplies the suction gas into the cylinder during the suction stroke. However, the purpose is to improve the efficiency of the compressor.

[0012]

In order to achieve this object, a reciprocating compressor according to the present invention comprises a hermetically sealed case, an electric compression element housed in the hermetically sealed case and constituted by a compression element and an electric motor, and a compression element. It is composed of a constituent cylinder, a suction passage connecting the suction pipe of the closed case and the cylinder, and a check valve mechanism provided in the suction passage.

Further, the check valve mechanism is composed of a valve and a cushioning material mounted on the surface of the valve or on the surface of the end surface of the suction passage facing the valve.

Further, the check valve mechanism is arranged such that the volume of the suction space between the check valve mechanism and the cylinder is at least 30% or more of the cylinder volume of the compressor.

[0015]

In the reciprocating compressor of the present invention, due to the above-mentioned structure, it is possible to prevent the backflow of the suction gas in the suction passage of the compression element, reduce the suction loss, and to close the valve of the check valve mechanism. You can prevent the collision noise that occurs,
Reliability is also improved. Further, it is possible to prevent the intake passage and the intake muffler from becoming larger than necessary, and it is possible to minimize the overheating of the intake gas.

[0016]

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 sectional view of a reciprocating compressor according to a first embodiment of the present invention. FIG. 2 is a sectional view of the suction passage taken along the line AA in FIG.

In FIGS. 1 and 2, reference numeral 4a designates a suction passage, in which a check valve mechanism 18 is provided. The check valve mechanism 18 is composed of a valve 18a and a spring 18b, and the valve 18a is opened when the intake gas flows from the intake pipe 14a to the intake passage 4a.
It is slumped in b. Reference numeral 19 denotes an end surface of the suction passage opened in the suction passage 4a.

The operation of the reciprocating compressor having the above structure will be described below. The reciprocating motion of the piston 5 causes the refrigerant to flow from the suction pipe 15, the suction pipe 14, the suction muffler 13, and the suction passage 1 formed of the suction passage 4a.
It intermittently flows into the cylinder 8 via 7. At this time, the valve 1 of the check valve mechanism 18 provided in the suction passage 4a
8a is opened by the flow of the suction gas.

In this suction stroke, there is no difference between the pressure in the suction passage 4a and the pressure in the suction pipe 14 or the suction muffler 13 due to the flow resistance of the suction passage 4a, the suction pipe 14 and the suction muffler 13. At this time, the valve 18
a is the suction pipe 14a due to the impulsive force of the spring 18b.
It is possible to prevent the backflow of the suction gas from the suction passage 4a to the suction pipe 14 and the suction muffler 13 by closely contacting with each other.

Therefore, in the intake stroke, the reverse flow of the intake gas from the intake passage 4a to the intake pipe 14 and the intake muffler 13 can be prevented, and the intake gas can always be supplied into the cylinder 8. As a result, inhalation loss can be reduced,
The efficiency of the compressor is improved.

As described above, the reciprocating compressor of this embodiment is
Since the check valve mechanism 18 including the valve 18a and the spring 18b is provided in the suction passage 4a, the reverse flow of the suction gas from the suction passage 4a to the suction pipe 14 and the suction muffler 13 can be prevented. Therefore, in the suction stroke, there is no state where the suction gas does not flow into the cylinder 8,
The suction loss can be reduced and the efficiency of the compressor is improved.

Although the check valve mechanism 18 is provided inside the suction passage 4a in this embodiment, it may be provided anywhere in the suction passage 17 composed of the suction muffler 13 and the suction pipes 14a and 14b. It goes without saying that the same effect can be obtained. Further, the check valve mechanism 18 including the valve 18a and the spring 18b has been described, but it goes without saying that the same effect can be obtained with other check valve mechanisms.

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

FIG. 3 is a sectional view of an intake passage of a reciprocating compressor according to a second embodiment of the present invention. In FIG. 3, 18
Reference numeral c is a cushioning material mounted on the surface of the valve 18a facing the suction passage end surface 19.

The operation of the reciprocating compressor having the above structure will be described below. When the refrigerant intermittently flows into the cylinder 8 via the suction passage 17, the suction passage 4
The valve 18a of the check valve mechanism 18 provided in a is opened by the flow of the suction gas. In this suction stroke, the pressure in the suction passage 4a, the suction pipe 14, the suction muffler 13
When there is no difference in the internal pressure or during the compression stroke,
The valve 18a is closed by the biasing force of the spring 18b. At that time, the valve 18a collides with the suction passage end surface 19 facing the valve 18a, but since the cushioning material 18c is attached to the surface of the valve 18a facing the suction passage end surface 19, the collision noise is prevented from being generated. In addition, the reliability of the valve 18a and the suction passage end surface 19 is improved.

As described above, the reciprocating compressor of this embodiment is
Since the check valve mechanism 18 including the valve 18a and the spring 18b and the cushioning member 18c mounted on the surface of the valve 18a are provided in the intake passage 4a, the intake gas does not flow into the cylinder 8 in the intake stroke. There is no condition, and inhalation loss can be reduced. In addition, valve 1
It is possible to prevent the collision noise from occurring when the valve 8a and the suction passage end surface 19 collide with each other, and the reliability of the valve 18a and the suction passage end surface 19 is improved.

In this embodiment, the cushioning material 18c is mounted on the surface of the valve 18a facing the suction passage end surface 19, but the cushioning material 18c is mounted on the surface of the suction passage end surface 19 facing the valve 18a. Needless to say, the same effect can be obtained.

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

FIG. 4 is a sectional view of the suction passage of the reciprocating compressor according to the third embodiment of the present invention. In FIG. 4, 20
Is a suction space formed when the valve 18a is in close contact with the suction passage end surface 19 and the suction lead 16b is in close contact with the suction hole 16a. Further, the valve 18a of the check valve mechanism 18 is configured such that the volume (V) of the suction space 19 is 30% or more of the cylinder volume (Vs) of the compressor.

The operation of the reciprocating compressor having the above structure will be described below. When the refrigerant intermittently flows into the cylinder 8 via the suction passage 17, the suction passage 4
The valve 18a of the check valve mechanism 18 provided in a is opened by the flow of the suction gas. In this suction stroke, the pressure in the suction passage 4a and the suction pipe 1 are affected by the flow resistance of the suction passage 4a, the suction pipe 14, and the suction muffler 13.
4. There is no difference in the pressure inside the suction muffler 13.

At this time, the check valve mechanism 18 to the cylinder 8
The volume (V) of the suction space 20 between them is the cylinder volume (V
s) is less than 30%, the valve 18a is
It cannot be closed in response to the pressure difference between the inside of a and the suction pipe 14 and the suction muffler 13. However, the volume (V) of the suction space 20 is 30 times the cylinder volume (Vs) of the compressor.
If the valve 18a of the check valve mechanism 18 is configured so as to be at least%, the valve 18a can be closed in response to the pressure difference between the inside of the suction passage 4a and the suction pipe 14 and the suction muffler 13. Confirmed by experiments.

Therefore, in the intake stroke, there is no situation where the intake gas flows backward from the intake passage 4a to the intake pipe 14 and the intake muffler 13 and the intake gas does not flow into the cylinder 8, so that the intake loss can be reduced and the compression loss can be reduced. The efficiency of the machine is improved. Furthermore, the volume (V) of the suction space 20 between the check valve mechanism 18 and the cylinder 8 is the cylinder volume (Vs) of the compressor.
The valve 18 of the check valve mechanism 18 should be 30% or more of
By configuring a, it is possible to prevent the suction space 20 from becoming larger than necessary, and it is possible to minimize the overheating of the suction gas.

As described above, the reciprocating compressor of this embodiment is
Since the valve 18a of the check valve mechanism 18 is configured such that the volume of the suction space 20 between the check valve mechanism 18 and the cylinder 8 is at least 30% or more of the cylinder volume of the compressor, the cylinder 8 in the suction stroke. Since there is no state where the suction gas does not flow into the inside, the suction loss can be reduced. further,
It is possible to prevent the suction space 20 from becoming larger than necessary,
The overheating of the inhaled gas can be minimized.

[0035]

As described above, according to the present invention, the closed case, the electric compression element that is housed in the closed case and is composed of the compression element and the electric motor, the cylinder that constitutes the compression element, and the suction pipe of the closed case. And a check valve mechanism provided in the suction passage, the suction pipe is connected to the suction pipe from the suction passage in the suction stroke.
There is no situation where the suction gas flows back to the suction muffler and the suction gas does not flow into the cylinder, so that the suction loss can be reduced and the efficiency of the compressor is improved.

Further, according to the present invention, since the check valve mechanism is constituted by the valve and the cushioning material is mounted on the valve surface or the surface of the end face of the suction passage opposite to the valve, In addition to the effect, it is possible to prevent the occurrence of collision noise when the valve is closed, and improve the reliability of the valve and the end surface of the suction passage.

Further, in the present invention, the volume of the suction space between the check valve mechanism and the cylinder is at least 3 times the cylinder volume of the compressor.
Since it is configured to be 0% or more, in addition to the effect of the first embodiment, it is possible to prevent the suction space from becoming larger than necessary, and it is possible to minimize the overheating of the suction gas.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a reciprocating compressor showing a first embodiment according to the present invention.

FIG. 2 is a sectional view of the suction passage taken along the line AA of the same embodiment.

FIG. 3 is a sectional view of an intake passage showing a second embodiment according to the present invention.

FIG. 4 is a sectional view of an intake passage showing a third embodiment according to 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.

FIG. 7 is a sectional view of a suction passage taken along line BB of the conventional example.

[Explanation of symbols]

 2 Airtight case 3 Electric motor 4 Compression element 8 Cylinder 9 Electric compression element 15 Suction pipe 17 Suction passage 18 Check valve mechanism 18a Valve 18c Cushioning material 19 Suction passage end face 20 Suction space

Claims (3)

[Claims] 1. A hermetically sealed case, and an electric compression element housed in the hermetically sealed case and configured by a compression element and an electric motor,
A reciprocating compressor including a cylinder that constitutes a compression element, a suction passage that connects the suction pipe of the hermetic case to the cylinder, and a check valve mechanism provided in the suction passage. 2. The reciprocating compressor according to claim 1, wherein the check valve mechanism is constituted by a valve, and a cushioning material is attached to a surface of the valve or a surface of an end surface of the suction passage facing the valve. 3. The reciprocating compressor according to claim 1, wherein the volume of the suction space between the check valve mechanism and the cylinder is at least 30% or more of the cylinder volume of the compressor.