JPS6056917B2 - hermetic compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hermetic compressor, particularly a hermetic refrigeration compressor provided with noise attenuation means.

In designing a highly efficient compressor, it is important to provide a relatively unrestricted suction gas flow to the compressor.

However, this suction process generates considerable noise due to the rapid flow of suction gas into the compressor and the action of the valves for suction. It is therefore desirable to provide some form of noise damping means in the suction gas flow path. It is also important for overall compressor efficiency to ensure a relatively free and unrestricted flow of suction gas to the compressor. Therefore, the use of various types of restriction or muffler devices in the main flow path is discouraged because such devices create excessive flow losses and require larger conduits to prevent compressor suction failure. This is undesirable because it will cause problems. Nowadays, compressors are required to be designed as compactly as possible.
The space available within the compressor places severe limitations on the dimensions of the suction muffler. Furthermore, these space constraints often require that the suction gas conduit be placed as close as possible to the discharge pipe. Therefore, since the discharge gas is relatively hot due to the compression process, it is desirable to minimize heat transfer to the suction gas to ensure high volumetric efficiency. A typical conventional example of a gas suction pipe and a silencer attached thereto in a hermetic compressor for refrigeration is disclosed in U.S. Pat.
- Corresponds to No. 120206.

) is disclosed. In this conventional example, a suction pipe for guiding suction gas from the inside of the compressor shell toward the compressor main body is formed to have a relatively small flow path cross-sectional area, and a large number of suction pipes are provided at the base end of the suction pipe. A muffler is provided that communicates with the inside of the outer shell through a small hole, and a bypass pipe that communicates with the inside of the outer shell through a small opening is attached to the tip side of the above-mentioned suction pipe. ing. This conventional example achieves noise reduction by restricting the gas flow.
It is based on the idea that the gas flow is restricted by the above-mentioned muffler and suction pipe that form the main suction gas flow path, and that the amount of suction gas that is insufficient can cause starvation (insufficiency) if only the main suction gas flow path is used. There is also a gas flow in the bypass pipe mentioned above, which compensates for this. Due to this limitation, sound deadening is achieved. Noise attenuation means for muffling the discharge gas of a compressor or for muffling air compressors, etc., are disclosed, for example, in Japanese Utility Model Publication No. 49-641 and U.S. Patent No. 49-641. 3645358 (corresponds to Utility Model Publication No. 49-642;

), U.S. Patent No. 2468454, U.S. Patent No. 2
297O46 and U.S. Reissue Patent No. As disclosed in No. 259O9, it is also known that a silencing chamber is provided, which is isolated from the gas flow path and communicated with the gas flow path through a large number of small communication ports or narrow slit-shaped communication ports. be. Such noise attenuation means mainly attenuates sound energy by imparting resistance to the gas flow by restricting the gas flow through a communication port with a small cross-sectional area between the gas flow path and the muffling chamber. Eliminate noise. The gas flow restriction type muffling mechanism described above is relatively difficult to manufacture because it includes small holes and communication ports for restricting gas flow.

A type of silencing mechanism equipped with a silencing chamber that is isolated from the gas flow path and communicated through a small-area communication port has a relatively small attenuated sound wave band width, and generally the silencing chamber forms the gas flow path. Since it is formed to surround the conduit, it is large in size. In a hermetic compressor that is sealed with an outer shell, interference between the noise damping mechanism and the inner wall of the outer shell is likely to occur, and this interference can cause noise and damage to components during operation and assembly of the compressor. It can happen. The above-mentioned interference is caused by the fact that conventional gas suction pipes and muffling mechanisms are made of metal, and if they are placed close to the compression mechanism, which generates heat during operation, the temperature of the suction gas will rise and the compressor will heat up. This is also aided by the fact that it has to be located close to the inner surface of the outer shell due to a decrease in volumetric efficiency. A principal object of the present invention is to provide a hermetic refrigeration compressor which minimizes the noise of arbitrary frequencies generated by the suction process while ensuring a substantially unrestricted flow path for the suction gas. An object of the present invention is to provide a novel compressor equipped with a noise reduction mechanism that effectively attenuates noise and is extremely easy to manufacture.

Another object of the present invention is to provide a gas suction pipe and a silencing mechanism that can be located close to the high temperature part of the compression mechanism without substantially reducing volumetric efficiency and effectively prevent interference with the compressor outer shell. An object of the present invention is to provide a new hermetic compressor for refrigeration, which is equipped with the following.

The hermetic compressor for refrigeration according to the present invention includes: A an outer shell; B a compressor body provided in the outer shell; C a motor device attached to the compressor body; and D a compressor body. an elongated suction tube device having one end attached to the tube, the suction tube device comprising: a a suction tube made from a plastic composition;
a suction pipe that forms a suction gas passage that is relatively large and has a substantially constant cross-sectional area from the inside of the outer shell to the compressor body, and that extends approximately in the vertical direction; b; a longitudinal direction of the suction pipe; a sealed elongated noise attenuating chamber which is arranged on one side of the suction pipe in the middle part so that the axes of the suction pipe are substantially parallel to each other, and c a single chamber provided on the wall of the suction pipe. a single communication port having a relatively large communication cross-sectional area so as to allow the above-described suction gas passage and the chamber to communicate without restriction at the lower end position of the chamber; The tube is constituted by an upper tube member and a lower tube member which are formed by being divided into parts at the portion where the communication port is provided when viewed in the length direction, and are fitted and fixed at their ends, and the chamber is , is characterized in that it is formed within the above-mentioned upper tube member.

As described above, this invention provides an elongated noise attenuation chamber that branches laterally from the suction gas passage and is approximately parallel to the suction gas passage. Due to the unrestricted communication provided by a single communication port with a large communication cross-sectional area, noise attenuation is achieved by a reactive muffler action in which the reflected waves cancel each other and attenuate the noise. The length of the chamber can be set arbitrarily in accordance with the fundamental frequency to be attenuated, and since the communication port is provided at one end of the chamber when viewed in the length direction of the chamber,
4) Wavelength attenuation can be obtained. The silencing mechanism according to the present invention that attenuates noise in this manner is in contrast to an orifice-type or resistance-type muffler in which the above-described noise attenuation chamber is communicated with the suction gas passage through a number of small communication ports. hand,
It has been found that the attenuation bandwidth is substantially large and the amount of attenuation is as good as that of the sound wave of the set fundamental frequency. As described above, the noise reduction mechanism according to the present invention provides a noise attenuation chamber separated from the suction gas passage, thereby ensuring a substantially unrestricted flow path for the suction gas, while attenuating noise very effectively. However, since the above-mentioned chamber is provided on one side of the suction pipe that forms the suction gas passage, the suction pipe and the noise attenuation chamber are installed inside the hermetic compressor, so that the suction pipe and the noise attenuation chamber are located on the inner peripheral surface of the outer shell. It is designed to be extremely compact and can be installed in parallel in the direction along the .

Therefore, it becomes easy to prevent interference with the outer shell by increasing the distance from the inner wall surface of the outer shell. Moreover, since the suction pipe was made of a plastic composition and the noise attenuation chamber was also sectioned with a plastic composition, it was possible to use a plastic composition that has a lower thermal conductivity than metal. Even if the suction pipe and the silencing mechanism attached thereto are placed close to the high temperature part, the temperature rise of the suction gas and therefore the decrease in volumetric efficiency can be suppressed. For this reason,
Place it close to a motor device that gets hot during operation,
The effect of preventing interference with the inner wall surface of the outer shell described above can be further enhanced. The suction pipe device equipped with the silencing mechanism according to the present invention is extremely easy to manufacture.

This is because the suction pipe forming the suction gas passage is divided into two pipe members at the portion where the single communication port is provided, when viewed in the length direction, and the aforementioned chamber for noise attenuation is formed. Same 2
Since it is formed in one of the main pipe members, two pipe members including the above-mentioned chamber and communication port can be manufactured by molding using a mold, and such a molded pipe This is because by fixing the members together at their ends, the suction pipe including the muffling mechanism can be immediately completed. The use of a plastic composition or its easy moldability further enhances the above-mentioned effects of ease of production, and it is also possible to use a mechanical method that utilizes the elasticity of the plastic composition to fit and fix both pipe members at their ends. It is assumed that a suitable engagement can be used. In the noise reduction mechanism according to the present invention, the single communication port that communicates the suction gas passage with the noise attenuation chamber is provided at the lower end of the chamber along the vertical direction. 1/4 wavelength attenuation is performed.

In this way, half-wavelength attenuation has a higher noise attenuation effect than quarter-wavelength attenuation. If the compressor is installed near the center position to perform half-wavelength attenuation, oil or liquid medium that may accompany the suction gas will accumulate in the chamber and reduce the effective length of the chamber, preventing continued operation of the compressor. As time passes, it becomes impossible to obtain the desired sound silencing effect. In contrast, according to the present invention, since the communication port is provided at the lower end of the noise damping chamber, oil or liquid medium does not accumulate in the chamber, and the effective length of the chamber is always maintained constant. The desired silencing effect is guaranteed over a long period of time. The invention will now be described in more detail with reference to the illustrated embodiments.

In the drawings, and in particular in FIG. A motor compressor (compressor main body) 14 is provided to support the compressor.

The motor compressor 14 is of the reciprocating piston type and includes a lower compressor housing 16 having a cylinder head 18 mounted on one side and a compressor housing 16 mounted at the upper end to drive the motor compressor 14. A motor device 20 is operatively connected to the machine 14. A cover 22 that covers the motor device 20 and surrounds the upper end of the motor device also includes:
This cover 22 is provided with a motor starter core (
It has a base portion 24 that comes into contact with the upper surface (not shown). a pair of substantially equal suction tube devices 30 and 31;
is also provided, and each suction pipe device 30, 31 is
Suction mufflers 32 and 33 are provided and are located between the base portion 24 of the cover 22 and the lower compressor housing 16. As clearly shown in FIGS. 2 and 3, the suction tube device 30 is comprised of two components, including an upper tube member 34 and a lower tube member 36. As shown in FIGS.

The upper tube member 34 includes a cylindrical tube section 38 having a hole 40 therethrough along its length and an open lower end 44.
an elongated chamber 42 having side walls 46, 48, 50;
The chamber 42, which is partitioned by the upper wall 52 and the outer wall 54 of the tube section 38, is integrally formed. This chamber 42 is arranged such that its axis is substantially parallel to the axis of the hole 40.
It is located. Lower tube member 36 also includes a cylindrical tube portion 56 having a hole 58 extending therethrough along its length.

Hole 58 has a diameter substantially equal to the diameter of hole 40 described above and is disposed concentrically therewith. ing. A projecting portion 62 is integrally formed at the upper end portion 60 of the lower tube member 36, and this projecting portion 62 extends from the side walls 64, 66, 6.
8 and an end wall 70 along the radial direction at the lower end.
The dimensions and shapes of the tube portion 56 and the overhang 62 are set so that the lower end 72 of the upper tube member 34 can be fitted therein. A step portion 74 extending in the circumferential direction is formed on the inner surface of the upper end portion 60 and the side walls 64, 66, 68, and the step portion 74 is formed along the circumferential direction.
4 relative to the lower tube member 36
4 is restricted from moving downward in a telescopic manner, whereby the end wall 70 of the overhanging portion 62 is distanced from the outer wall portion 54 in the vertical direction, and the holes 40 and 58 and the chamber 42 are communicated with each other. A communication port 76 is formed. Therefore, when the upper tube member 34 and the lower tube member 36 are fixed to each other,
A substantially continuous and unrestricted fluid path is defined for conducting suction gas from shroud 22 to suction gas passage 78 in lower compressor housing 16 .

Communication port 76 allows fluid communication between 42 and holes 40 and 58 and serves to reduce noise generated by the inhalation process. Preferably, as shown in FIG. 3, the communication ports 76 extend circumferentially over an angular range of approximately 180 degrees, with a total communication area approximately equal to the cross-sectional area of the chamber 42. and spans a length range that provides communication between the holes 40 and 58. The length of the chamber 42 is one quarter of the wavelength of the fundamental noise frequency to be attenuated.
(114). The length of the chamber 42 for any desired fundamental frequency can be easily calculated by the following formula: As the volume of the chamber 42 increases, the center Although the attenuation for the fundamental frequency increases and the attenuation bandwidth also increases, it should be noted that if the same volume becomes too large, the center fundamental frequency tuning will be lost.

Additionally, in order to obtain proper damping with minimal interference with the flow of inhaled gas, the width of the chamber 42 should be smaller than the length of the chamber 42 to allow resonance to occur along its length. Facts should also be kept in mind. The above-described suction pipe device 31 is configured in substantially the same manner as the suction pipe device 30 described above, so a description thereof will be omitted. Both the upper tube member 36 and the lower tube member 38 of the inhalation tube device 30 are fabricated from a polymeric composition by injection molding or by any other suitable method.

Many types of plastics are suitable for this purpose, but nylon or AlOx (General Electric, Pittsfield, Mass., USA)
Company (GeneraI Electric CO.)
Glass fiber-reinforced thermoplastic polyesters such as those sold by A.G., Inc. are particularly suitable as they exhibit high resistance to deterioration in the presence of refrigerants and lubricating oils and at the temperatures to which they are exposed in the compressor. The use of polymeric compositions is particularly desirable since plastics have a relatively low heat transfer capacity compared to metals. In order to maintain high volumetric efficiency within the compressor, it is important to suppress the transfer of compression heat from the discharge gas to the suction gas as much as possible. Referring again to FIGS. 1 and 2, the above-mentioned cover 22
A pair of through holes 80 and 82 are provided in the base portion 24 of the unit, and the suction pipe device 3 is inserted into the through holes 80 and 82.
The upper ends 84 and 84'' of 0 and 31 are inserted, respectively.

Upper tube member 34 has a shoulder 86 near its upper end 84 that engages a lower surface 88 of base portion 24 . In order to retain the suction tube devices 30 and 31 in the respective through holes 80 and 82, the inner ends (upper ends) of the suction tube devices 30, 31 are
can easily be expanded radially outward or shaped accordingly. Alternatively, if desired, as shown in FIG. 4, the upper end 90 of the upper tube member 92 includes a plurality of radially outwardly directed projections 94 that resiliently engage the cover base 24''. As shown clearly in FIG. This draft angle is necessary to facilitate removal from the mold during manufacturing. This draft angle extends from the upper end 60 to the lower end 96 of the tube section 56.
By gradually decreasing the outer diameter of the lower end 96,
It may be frictionally fitted and retained within the suction gas passageway 78 of the lower compressor housing 16. This friction fit allows the suction pipe devices 30, 31 to easily accommodate slight dimensional changes due to thermal expansion of the compressor components while maintaining a resiliently fitted state with the passage 78. Additionally, plastic compositions, in contrast to metals, are slightly deformable;
The end 96 is slightly deformable to accommodate deviations from the circular shape of the passageway 78 to ensure a sealing engagement between the end 96 and the passageway 78 .
Lubricating oil is prevented from entering the 8. If desired, to further ensure a seal for passageway 78,
A suitable adhesive may be applied to the end 96. During the inhalation process, the inhaled gas enters the hermetically sealed outer shell 12 through a suitable inlet (
(not shown) from which it is drawn into the jacket 22 and flows around the ends of the motor windings to cool the motor arrangement 20.

The inhalation gas is then transferred from within the cover 22 to the inhalation devices 30, 31.
through which the suction gas is drawn downwardly into the suction gas passage 78 and from there into the compression chamber. As the gas flows through the suction pipe arrangement 30, 31, the noise and valve noise generated by the relatively high velocity pulsating flow is effectively attenuated by the suction mufflers 32, 33. The suction mufflers 32, 33 can be installed at any position in the length direction of the suction pipe devices 30, 31;
33 has been found to be more effective when placed close to the upper ends of the suction tube devices 30, 31. Furthermore, since the communication port 76 of the suction muffler into the chamber 42 is located at the bottom of the chamber 42, oil or liquid refrigerant that may be accompanied by the suction gas does not accumulate in the chamber 42. Further, by using a plastic material as the material for the suction pipe devices 30, 31, heat transfer from the discharged gas is reduced, and the volumetric efficiency of the compressor is ensured. Yet again. Plastic pipes have relatively high elastic deformability compared to metal pipes, so
The tube end 96 readily undergoes slight deformation to accommodate deviations from the circular shape of the suction gas passageway 78. This achieves a fluid-tight seal and prevents the introduction of oil or the like which could cause slugging of the compressor. Additionally, by using the plastic composition, an integrated suction pipe and muffler device can be manufactured relatively inexpensively. That is, the plastic composition can be easily molded into two parts, and the two parts can be easily joined together using a suitable adhesive.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway and partially longitudinally sectional front view of an embodiment of a refrigeration compressor according to the present invention. 2 is an enlarged longitudinal sectional front view showing a suction pipe device with a suction muffler provided in the compressor shown in FIG. 1. FIG. Figure 3 is a cross-sectional view taken along line 3-3 of Figure 2.
The figure is a partially longitudinal front view showing the upper end of the suction pipe device according to a modification of the embodiment shown in FIGS. 1-3. 10...
Compressor, 12... Outer shell, 14... Motor compressor (
compressor body), 20... motor device, 22... cover,
24... Base portion of cover 22, 30, 31... Suction pipe device, 32, 33... Suction muffler, 34... Upper pipe member, 36... Lower pipe member, 38... Cylindrical tube portion, 40... Hole, 42... Chamber, 56... Cylindrical tube portion, 58... Hole, 62... Overhang portion, 74...
・Stepped portion, 76...Communication port, 78...Suction gas passage,
80, 82...Through hole, 92...Upper tube member.

Claims (1)

[Scope of Claims] 1. A hermetic compressor for refrigeration, comprising: A: an outer shell; B: a compressor body provided within the outer shell; and C: a motor device attached to the compressor body; , D, an elongated suction pipe device having one end attached to the compressor body, the suction pipe device comprising: a) a suction pipe made from a plastic composition, and comprising: a suction pipe made from a plastic composition; a suction pipe forming a suction gas passage substantially vertically extending from the inside of the suction pipe to the compressor main body and having a relatively large and almost constant cross-sectional area; a sealed elongated noise damping chamber arranged on one side of the suction pipe so that the axes of the suction pipe are substantially parallel to the axes of the suction pipe; and c a single communication port provided in the wall of the suction pipe. A single communication port having a relatively large communication cross-sectional area is provided to allow the above-described suction gas passage and the chamber to communicate without restriction at a lower end position of the chamber, and the suction pipe has a long length. It is composed of an upper pipe member and a lower pipe member that are formed by being divided into parts at the portion where the communication port is provided when viewed in the horizontal direction, and are fitted and fixed at their ends, and the above-mentioned chamber is connected to the above-mentioned upper part. A hermetic compressor formed within a pipe member. 2. The hermetic compressor according to claim 1, in which a horizontal overhang is formed at the upper end of the lower pipe member and extends in the direction of the chamber for noise attenuation, and the communication port is closed. , a hermetic compressor located within the overhang and provided at the upper end of the lower tube member.