JPH0267497A - Muffling device for hermetic compressor - Google Patents

Abstract

PURPOSE:To damp the extent of pressure pulsation being produced in a cylinder by constituting a space opening to be almost orthogonal with a flow direction of working fluid flowing through a notch toward a discharge port from a high pressure chamber. CONSTITUTION:A space 18 installed in a notch 17 of a cylinder 5 is opened so as to be orthogonal with a flow direction of working fluid flowing through the notch 17 toward a discharge port 15 from a high pressure chamber of this cylinder. With this constitution, a pressure pulsation component by sudden expansion of the working fluid compressed at the time of discharge processes and another pressure pulsation component by being suddenly expanded due to open into a low pressure chamber 8 of the compressed working fluid left behind in and around the discharge port 15 at the time of completion of the discharge process when a discharge valve 16 is closed, both are damped, and thereby a level of pressure waves being transmitted to the inside of a discharge muffler chamber 14 and/or the cylinder 5 is abated.

Description

[Detailed description of the invention] (B) Industrial application fields This invention relates to an improvement in a silencer for a hermetic compressor.

BACKGROUND OF THE INVENTION A conventional hermetic compressor has a structure as shown in, for example, Japanese Patent Publication No. 11200/1983. Here, a conventional example will be explained with reference to this publication. In FIGS. 6 and 7, 5o is a closed container having a suction pipe 51 and a discharge pipe 52, and an electric element 53 and a compression element 54 driven by the electric element are housed inside this container. .

Reference numeral 55 denotes a cylinder with both ends open, and a roller 57 rotatably fitted to a part of the rotating shaft 56 is installed in the cylinder.
It's decorated. A vane 58 that divides the inside of the cylinder into a low-pressure chamber and a high-pressure chamber is provided in a part of the cylinder 55 so as to be freely retractable into a guide groove 59, and one end of the vane is always kept in close contact with the side surface of the roller 57. A spring 60 is provided within the guide groove 59 to allow the guide groove to move. -Also, cylinder 5
A rotating shaft 56 is pivotally supported at both ends of the cylinder 5.
An upper bearing part 61 and a lower bearing part 62 are provided, respectively, to seal the end faces of the shaft 5. Reference numeral 63 designates a discharge port formed in the lower bearing portion 62, which communicates with a high pressure chamber within the cylinder 55, and a discharge valve 64 and a discharge valve holder 65 are provided on the discharge side of the discharge port 63, respectively. ing. 66
is a small volume space formed in a complicated manner that comes into contact with the cylinder 55 of the lower bearing portion 62, and this small volume space communicates with the discharge port 63 via a pressure introduction path 67. The width of the pressure introduction path 67 is formed to be smaller than the width of the small volume space 66, as shown in FIG.

Reference numeral 68 denotes a discharge muffler body formed in a dish shape so as to cover the surface of the lower bearing portion 62, and a discharge muffler chamber 69 is formed inside this muffler body.

In a hermetic compressor with this structure, the cylinder 5 of the lower bearing part 62
5 is connected to the discharge port 63 through a pressure introduction path 67 to form a resonant muffler, thereby damping the pressure pulsations of the refrigerant and reducing the noise of the compressor. There is.

(c) Problems to be Solved by the Invention However, in the resonance type muffler, the small volume space 66 and the pressure introduction path 67 are formed in the thin lower bearing part 62 in separate processes, so that the strength is not reduced. There was a problem that it became difficult to process.

The present invention solves the above-mentioned problems, and provides a noise reduction device for a hermetic compressor, which is intended to facilitate space processing and attenuate pressure pulsations generated within a cylinder.

(d) Means for Solving the Problems This invention includes a compression element housed in a closed container, a cylinder, a roller rotating inside the cylinder by an eccentric part of a rotating shaft, and a low pressure chamber in contact with the roller inside the cylinder. It consists of a vane that partitions the cylinder into a high-pressure chamber, and a bearing that seals the opening of the cylinder.The bearing is provided with a discharge port and a discharge valve that opens and closes the discharge port, and the cylinder is equipped with a discharge port and a high-pressure chamber. A notch is provided to communicate with the chamber, a cylindrical space with a bottom is provided in the notch, and the opening of the space is approximately perpendicular to the flow direction of the working fluid flowing through the notch from the high pressure chamber toward the discharge port. This is what I did.

(*) Effect By having the above-described structure, this invention has a bottomed cylindrical shape whose opening is substantially perpendicular to the notch with respect to the flow direction of the working fluid flowing through the notch from the high pressure chamber toward the discharge port. The space is provided to attenuate pressure pulsations in the working fluid, prevent the compressor from vibrating due to pressure pulsation waves, and simplify processing.

(f) Examples The present invention will be explained below based on the examples shown in FIGS. 1 to 4.

Reference numeral 1 denotes a closed container, in which an electric element 3 having a rotation shaft 2 on the upper side and a rotary compression element 4 driven by the rotation shaft 2 of this electric element on the lower side are housed. The element 4 includes a cylinder 5, an eccentric portion 6 of the rotating shaft 2,
A roller 7 that fits into this eccentric portion and rotates inside the cylinder 5, a vane 10 that comes into contact with this roller and divides the inside of the cylinder 5 into a low pressure chamber 8 and a high pressure chamber 9, and an upper bearing that closes the opening of the cylinder 5. 11, a lower bearing part 12, and a discharge muffler body 13 attached so as to cover the surface of this upper bearing part. The upper bearing portion 11 is provided with a discharge port 15 that communicates the high pressure chamber 9 of the cylinder 5 with a discharge muffler chamber 14 formed inside the discharge muffler body 13 . A discharge valve 16 for opening and closing the discharge port 15 is attached to the upper bearing portion 11 on the outlet side of the discharge port. Reference numeral 17 denotes a notch provided in the cylinder 5, and this notch is formed obliquely in a spherical shape so as to smooth the flow of working fluid from the high pressure chamber 9 to the discharge port 15. 18 is a cylindrical space with a bottom, and this space has an opening perpendicular to the notch 17. 19 is a suction passage formed in the cylinder 5, and this suction passage communicates with the low pressure chamber 8. 20 is a discharge pipe, and this discharge pipe is attached to the earthen wall of the closed container 1.

In the silencer for a hermetic compressor configured as described above, the working fluid flowing into the cylinder 5 from the suction passage 19 is compressed by the cooperation of the roller 7 and the vane 10, and the discharge valve 16 is opened from the discharge port 15. Discharge muffler body 13
is discharged into the discharge muffler chamber 14. The working fluid in this discharge muffler body passes through the closed container 1 to the discharge pipe 20.
to an external cooling circuit (not shown).

The space 18 provided in the notch 17 of the cylinder 5 is opened perpendicularly to the flow direction of the working fluid flowing through the notch 17 from the high pressure chamber 9 of the cylinder toward the discharge port 15 during the discharge stroke. This is due to the pressure pulsation component due to the rapid expansion of the compressed working fluid, and the sudden expansion due to the release of the compressed working fluid remaining near the discharge port 15 to the low pressure chamber 8 at the end of the discharge stroke when the discharge valve 16 closes. The pressure pulsation component is attenuated, and the level of pressure waves transmitted to the discharge muffler chamber 14 and cylinder 5 is reduced. Furthermore, the space 18 is configured to attenuate frequency components that transmit noise to the outside using a resonant muffler mechanism, thereby suppressing noise in the entire frequency band to a low level.

Next, the noise characteristics of the compressor having the above configuration will be explained.

The test conditions were a 675W compressor and a condensing temperature of 54.4℃.
, evaporation temperature 7.2℃, discharge temperature 100℃, suction temperature 35℃
The experiment was carried out using a refrigerant of 22 °C and R22.

As a result, as shown in FIG. 5, the noise in the entire frequency band was reduced.

That is, the frequency of a specific pressure pulsating wave that is a source of noise excitation is attenuated in the space 18, thereby reducing the noise of the compressor.

Further, by making the volume of the space 18 extremely small compared to the volume inside the cylinder 5, a decrease in the efficiency of the compressor can be suppressed.

Therefore, in the present invention, by providing a space 18 in the notch 17 of the cylinder 5, it is possible to simplify the machining of this space and to reduce noise.

In the above description, the compressor is operated at the rated operating frequency, but it goes without saying that the same effect can be obtained even if the compressor is applied to an inverter compressor whose operating frequency changes.

(G) Effects of the Invention The silencer for a hermetic compressor of the present invention has a compression element housed in a hermetic container, a cylinder, a roller that rotates the cylinder by an eccentric part of a rotating shaft, and a roller that is in contact with the roller and inside the cylinder. It consists of a vane that divides the cylinder into a low pressure chamber and a high pressure chamber, and a bearing that closes the opening of the cylinder, and the bearing is provided with a discharge port and a discharge valve that opens and closes the discharge port,
In addition, the cylinder is provided with a notch that communicates the discharge port and the high pressure chamber, and a bottomed cylindrical space is provided in the notch, and the working fluid flows in the direction of flow of the working fluid flowing through the notch from the high pressure chamber toward the discharge port. Therefore, by making the opening of the space provided in the cutout substantially perpendicular to the flow direction of the working fluid flowing along the notch, the compressed air near the discharge port can be reduced. It is possible to attenuate a specific frequency band that excites the compressor among the pressure pulsation components caused by the rapid expansion of the working fluid, thereby reducing noise. Moreover, since this invention provides a space in the notch of the cylinder,
It can be easily processed.

[Brief explanation of the drawing]

1 to 4 show the present invention, FIG. 1 is a longitudinal sectional view of a rotary compressor, FIG. 2 is a cross-sectional view of the rotary compressor, and FIG. 3 is an enlarged sectional view of main parts of a discharge port section. , Figure 4 is A of Figure 3.
- A sectional view, Fig. 5 is a noise analysis diagram, Figs. 6 and 7 show conventional examples, Fig. 6 is a longitudinal sectional view of the rotary compressor, and Fig. 7 is a noise analysis diagram.
The figure is a perspective view of the main parts of the muffler mechanism. DESCRIPTION OF SYMBOLS 1... Airtight container, 2... Rotating shaft, 3... Electric element, 4... Rotating compression element, 5... Cylinder, 6... Eccentric part, 7... Roller, 8...
...Low pressure chamber, 9...High pressure chamber, 10...Vane, 11...Upper bearing section, 12...Lower bearing section,
15...Discharge port, 16...Discharge valve, 1
7... Notch, 18... Space. Figure 3! ! ! ! !

Claims (1)

[Claims] 1. An electric element having a rotating shaft and a compression element driven by the rotating shaft of the electric element are housed in a closed container,
This compression element includes a cylinder, an eccentric part of a rotating shaft, a roller that rotates inside the cylinder by this eccentric part, a vane that comes into contact with this roller and divides the inside of the cylinder into a low pressure chamber and a high pressure chamber, and an opening in the cylinder. It consists of a bearing part that seals the
In the hermetic compressor, the bearing portion is provided with a discharge port and a discharge valve for opening and closing the discharge port, and the cylinder is provided with a notch portion communicating the discharge port and the high pressure chamber. The notch of the cylinder is provided with a bottomed cylindrical space, and this space is substantially orthogonal to the flow direction of the working fluid flowing through the notch from the high pressure chamber toward the discharge port. Silencer for hermetic compressors. 2. The hermetic compressor according to claim 1, wherein the notch is provided in the cylinder obliquely with respect to the axis of the rotating shaft, and the bottomed cylindrical space is provided orthogonally to the notch. Silencer.