JPH08326679A - Rotary compressor - Google Patents

Abstract

PURPOSE: To sharply reduce columnar resonance in a closed container caused by pressure pulsation of discharging gas and vibration caused by pressure pulsation in the cylinder of a rotary compressing element, and reduce noise on operation. CONSTITUTION: A device consists of a motor element 2 on the lower part in an closed vessel 1 in which refrigerating machine oil O is reserved in a inner bottom part, and a rotary compressing element 4 driven by the motor element 2. The cylinder 5 of the rotary compressing element 4 is interposed between a main bearing 6 for journalling the shaft 3 of the motor element 2 and an auxiliary bearing 7, the cylinder 5 is connected and fixed to the inner circumferential side wall la of the closed vessel 1, and space 10 is formed between the upper end surface 5a of the cylinder 5 and the bottom surface part of the motor element 2. The boundary surface of the space 10 is formed of a noise absorbing material (the oil surface L of the refrigerating machine oil O).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary compressor mounted in, for example, an air conditioner or a refrigerator, and more particularly to a boundary of a space formed between an electric element and a rotary compression element in a hermetic container. By devising the surface structure, it is possible to significantly reduce the air column resonance in the closed container due to the pressure pulsation of the discharge gas and the vibration due to the pressure pulsation in the cylinder of the rotary compression element, and to reduce the noise during operation. It is the one.

[0002]

2. Description of the Related Art Conventionally, in this type of rotary compressor, as shown in FIG. 6, for example, an electric element 2 is provided in a lower portion of a closed container 1 in which a refrigerating machine oil O is stored in an inner bottom portion, and an electric element 2 of this electric element. 2 and a rotary compression element 4 driven by a shaft 3 of the rotary electric compressor 2.
Is interposed between a main bearing 6 and a sub-bearing 7 that axially support the shaft 3, and the cylinder 5 is joined and fixed to the inner peripheral side wall surface 1a of the closed container 1, and the cylinder 5 There is a structure in which a space 10 is formed between the upper end surface 5a of the electric motor 2 and the lower surface 2a of the electric element 2 and the shape of the cylinder 5 is a squid type as shown in FIG. .

[0003]

However, in the rotary compressor having the above-mentioned conventional structure, when the squid-shaped cylinder 5 is adopted as the rotary compression element 4, the number of joints with the hermetically sealed container 1 is small. It is difficult to reduce the vibration of the high-frequency closed container 1.

Further, as shown in FIGS. 8 and 9, even when the conventional round-shaped cylinder 5 is adopted, most of the boundary surface of the space 10 is formed by a rigid wall. Since the sound wave energy has a reflectance close to 100%, it is difficult to reduce the air column resonance in the closed container 1 due to the pressure pulsation of the discharge gas and the vibration due to the pressure pulsation in the cylinder 5. The noise level cannot be reduced.

FIG. 10 shows the measurement results of the resonance frequency near the air gap, near the cup discharge hole, and near the stator core in the space 10 when the conventional round cylinder 5 is adopted. It can be seen that since the interface is formed by a rigid wall, there are many resonance modes and the sound pressure absolute value is also large.

An object of the present invention is to significantly reduce air column resonance in a closed container due to pressure pulsation of discharge gas and vibration due to pressure pulsation in a cylinder of a rotary compression element to reduce noise during operation. The object is to provide a rotary compressor capable of

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to an electric element at a lower part of a closed container in which refrigerating machine oil is stored at an inner bottom and a rotary compression driven by the electric element. An element, and a cylinder of this rotary compression element is interposed between a main bearing and a sub-bearing that axially support the shaft of the electric element to be joined and fixed to the inner peripheral side wall of the hermetically sealed container, and A space is formed between the upper end surface and the lower surface of the electric element, and a part of the boundary surface of the space is formed of a sound absorbing material.

[0008]

That is, according to the present invention, by adopting the above-mentioned structure, a part of the boundary surface of the space between the upper end surface of the cylinder of the rotary compression element and the lower surface portion of the electric element is made of a sound absorbing material. Therefore, due to the sound absorption coefficient of the sound absorbing material, the resonance frequency in the space is shifted to the higher order, and the low frequency is reduced.

Further, when a part of the boundary surface of the space is used as the end surface of the cylinder and a round cylinder is adopted, the number of joints with the closed container increases, so that a high frequency due to pressure pulsation in the cylinder occurs. It is possible to suppress the vibration and vibration of the system to a minimum, and it is possible to reduce the noise level over a wide range from the low frequency region to the high frequency region, whereby the noise during operation can be reduced.

Further, by immersing 50% or more of the area of the upper end surface of the cylinder forming one of the boundary surfaces of the space in the refrigerating machine oil as the sound absorbing material, the sound pressure level of the space is reduced and the resonance frequency is reduced. Shift to higher levels.

Furthermore, by setting the thickness between the upper and lower end surfaces of the cylinder to 45% to 85% of the total thickness of the cylinder, the weight of the cylinder can be reduced, the cost can be reduced, and the weight of the compressor as a whole can be reduced. To do.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described in detail with reference to the drawings shown in FIGS. 1 to 5. A rotary compressor according to the present invention has a conventional structure as shown in FIGS. It has the same overall structure as that of the rotary compressor using the round cylinder.

That is, in the rotary compressor according to the present invention, as shown in FIG. 1, an electric element 2 is provided in a lower portion of a closed container 1 in which refrigerating machine oil O is stored in an inner bottom portion, and the electric element 2 is provided.
A rotary compression element 4 driven by a shaft 3 of the rotary compression element 4 and a cylinder 8 of the rotary compression element 4 between a main bearing 6 and a sub bearing 7 which axially support the shaft 3 of the electric element 2.
This cylinder 5 is joined to and fixed to the inner peripheral side wall surface 1a of the hermetically sealed container 1, and a space 10 is formed between the upper end surface 5a of the cylinder 5 and the lower surface portion 2a of the electric element 2. It has a configuration of

The cylinder 5 has a round shape as shown in FIG. 2, and the upper end surface 5a of the cylinder 5 is one of the boundary surfaces of the space 10 and is hatched in FIG. As shown, the thickness T between the upper and lower end surfaces 5a and 5b
1, the area ratio according to the entire cylinder thickness T is set to 45% to 85%, and as shown by the diagonal lines in FIG. 3, 50% or more of the area of the upper end surface 5a thereof is the refrigerating machine oil O.
The refrigerating machine oil O is used as one of the boundary surfaces of the space 10 by raising the level of the oil surface L so as to be immersed in.

By the way, the reason why the area of the upper end surface 5a of the cylinder 5 immersed in the refrigerating machine oil O is set to 50% or more is that the boundary surface of the space is usually determined when the sound field characteristic in the closed space is calculated. When a sound absorbing material is present, the calculation is performed by giving the normal incident acoustic impedance, but at the boundary between the boundary surface of this sound absorbing material and the boundary surface composed of other rigid walls,
The particle velocity tends to be faster and the sound pressure at the resonance frequency tends to be higher, and when comparing the sound pressure between the boundary surface of the sound absorbing material and the boundary surface of the rigid wall, the boundary surface of the sound absorbing material is This is because the sound pressure tends to be significantly low.

Further, the upper and lower end surfaces 5 of the cylinder 5 are
The reason why the thickness ratio T1 between a and 5b is set to be 45% to 85% based on the entire cylinder thickness T is that the oil level L of the refrigerating machine oil O becomes a hard wall surface when it is 85% or more. This is because the low frequency sound cannot be reduced, and if it is 45% or less, the cylinder inner diameter and the vane slot width are distorted due to shrinkage fitting of the case into the closed container 1 and tack welding. This is because not only the performance of the compressor itself is greatly affected, but also the vibration of the closed container itself cannot be completely suppressed, and high frequency noise cannot be reduced.

FIG. 4 shows the technical idea of the present invention, for example, the measurement result of the resonance frequency in the vicinity of the air gap, the cup discharge hole, and the stator core of the space 10 when the squid-shaped cylinder 5 is adopted. , Fig. 10
Compared with the case where the entire boundary surface of the space 10 is formed by a rigid wall when the conventional round-shaped cylinder 5 shown in FIG. 1 is adopted, the resonance mode is reduced and the sound pressure absolute value is also reduced. I understand that.

Further, FIG. 5 shows a comparison of noise between the rotary compressor of the present invention and the conventional rotary compressor.
The low frequency range in the dotted circle (a) in the figure represents the effect of immersing the upper end surface 5a of the cylinder 5 in the refrigerating machine oil O, and the high frequency range in the dotted circle (b) in the figure is The effect obtained by adopting the round-shaped cylinder 5 is shown, whereby the characteristic of frequency (Hz) A is
The sound pressure level (dB) was reduced to about 3 dB.

[0019]

As is apparent from the above description, the present invention is provided with the electric element in the lower portion of the closed container in which the refrigerating machine oil is stored in the inner bottom and the rotary compression element driven by the electric element. The cylinder of the rotary compression element is interposed between a main bearing and a sub bearing that axially support the shaft of the electric element, and is fixed by being joined to the inner peripheral side wall of the hermetic container, and the upper end surface of the cylinder and the Since a space is formed between the lower surface of the electric element and a part of the boundary surface of this space is made of a sound absorbing material, the sound absorbing coefficient of the sound absorbing material reduces the resonance frequency in the space. It is possible to shift to a higher order, which makes it possible to reduce low frequencies and thus reduce noise during operation.

Further, when a part of the boundary surface of the space is used as the end surface of the cylinder and a round cylinder is used, the number of joints with the closed container increases, and high frequency vibration due to pressure pulsation in the cylinder occurs. Since the vibration can be suppressed to the minimum, the noise level can be reduced over a wide range from the low frequency range to the high frequency range.

Further, in claim 2, the sound pressure level of the space is reduced by immersing 50% or more of the area of the upper end surface of the cylinder forming one of the boundary surfaces of the space in the refrigerating machine oil as the sound absorbing material. It is possible to shift the resonance frequency to a higher order.

Furthermore, in claim 3, by setting the thickness between the upper and lower end surfaces of the cylinder to 45% to 85% of the total thickness of the cylinder, the weight of the cylinder is reduced,
As a result, the cost can be reduced and the weight of the entire compressor can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of essential parts showing an embodiment of a rotary compressor according to the present invention.

FIG. 2 is a plan view showing the area ratio between the entire thickness of the cylinder of the rotary compression element and the end face thickness with diagonal lines.

FIG. 3 is a plan view showing the area of the end surface of the cylinder which is also immersed in the refrigerating machine oil, in a shaded manner.

FIG. 4 is an explanatory diagram showing a measurement result of a resonance frequency of a space when a round-shaped cylinder is adopted.

FIG. 5 is an explanatory diagram comparing noise measurement results of the rotary compressor of the present invention and a conventional rotary compressor.

FIG. 6 is a sectional view of an essential part showing an example of a conventional rotary compressor.

FIG. 7 is a plan view of a conventional squid-shaped cylinder.

FIG. 8 is a sectional view of a main part showing another example of a conventional rotary compressor.

FIG. 9 is a plan view of a conventional cylinder having a round shape.

FIG. 10 is an explanatory view showing a measurement result of a resonance frequency in a space when a conventional circular cylinder is also used.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Airtight container, 1a ... Inner peripheral side wall surface, 2 ... Electric element, 2a ... Lower surface part, 3 ... Shaft, 4 ... Rotary compression element, 5 ... Cylinder, 5a, 5b ... End surface, 6 ... Main bearing, 7 ... Sub bearing, 10 ... Space, T ... Total thickness of cylinder, T1 ... Thickness between upper and lower end surfaces of cylinder, O ... Refrigerating machine oil (sound absorbing material).

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shoji Yamanaka 2-5-5 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd.

Claims (3)

[Claims] 1. An electric element and a rotary compression element driven by the electric element are provided in a lower portion of a closed container in which refrigerating machine oil is stored at an inner bottom portion, and a cylinder of the rotary compression element is provided with a shaft of the electric element. Is interposed between a main bearing and a sub-bearing that support the shaft and is joined and fixed to the inner peripheral side wall of the closed container, and a space is formed between the upper end surface of the cylinder and the lower surface portion of the electric element. The rotary compressor is characterized in that the boundary surface of this space is made of a sound absorbing material. 2. The rotary compressor according to claim 1, wherein 50% or more of the area of the upper end surface of the cylinder forming one of the boundary surfaces of the space is immersed in the refrigerating machine oil as the sound absorbing material. . 3. The rotary compressor according to claim 1, wherein the thickness between the upper and lower end surfaces of the cylinder is set to 45% to 85% of the total thickness of the cylinder.